* [PATCH v14 01/16] cxl: Drop stale decoder interleave limit comment
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 02/16] cxl: Share CXL port upstream PCI device lookup Srirangan Madhavan
` (14 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan,
Jonathan Cameron
CXL 2.0 added 16-way memory interleaving, making the comment that the
specification supports only 8-way interleaving stale. Remove the comment
without changing CXL_DECODER_MAX_INTERLEAVE.
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Link: https://lore.kernel.org/linux-cxl/20260912003057.3db9335c@jic23-hlaptop/
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
---
drivers/cxl/cxl.h | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 3ef0810ab86b..9e0500d56866 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -269,10 +269,6 @@ enum cxl_decoder_type {
CXL_DECODER_HOSTONLYMEM = 3,
};
-/*
- * Current specification goes up to 8, double that seems a reasonable
- * software max for the foreseeable future
- */
#define CXL_DECODER_MAX_INTERLEAVE 16
#define CXL_QOS_CLASS_INVALID -1
base-commit: fef22d37d47043b63e4007f2f5fe762fa21fae0c
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 02/16] cxl: Share CXL port upstream PCI device lookup
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 01/16] cxl: Drop stale decoder interleave limit comment Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 03/16] cxl: Move decoder declarations to shared header Srirangan Madhavan
` (13 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan,
Jonathan Cameron
read_cdat_data() resolves a CXL port's upstream device to its backing PCI
device. HDM cache updates need the same mapping.
Factor the lookup into cxl_port_get_uport_pci_dev() and return a referenced
PCI device to make caller ownership explicit.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
---
drivers/cxl/core/core.h | 1 +
drivers/cxl/core/pci.c | 19 +++++--------------
drivers/cxl/core/port.c | 26 ++++++++++++++++++++++++++
3 files changed, 32 insertions(+), 14 deletions(-)
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 35eaf636adc9..983d7690c3a5 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -157,6 +157,7 @@ long cxl_pci_get_latency(struct pci_dev *pdev);
int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c);
int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
struct access_coordinate *c);
+struct pci_dev *cxl_port_get_uport_pci_dev(struct cxl_port *port);
static inline struct device *port_to_host(struct cxl_port *port)
{
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9d807c1a002c..99c8b02d42e5 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -564,26 +564,13 @@ static unsigned char cdat_checksum(void *buf, size_t size)
*/
void read_cdat_data(struct cxl_port *port)
{
- struct device *uport = port->uport_dev;
+ struct pci_dev *pdev = cxl_port_get_uport_pci_dev(port);
struct device *dev = &port->dev;
struct pci_doe_mb *doe_mb;
- struct pci_dev *pdev = NULL;
- struct cxl_memdev *cxlmd;
struct cdat_doe_rsp *buf;
size_t table_length, length;
int rc;
- if (is_cxl_memdev(uport)) {
- struct device *host;
-
- cxlmd = to_cxl_memdev(uport);
- host = cxlmd->dev.parent;
- if (dev_is_pci(host))
- pdev = to_pci_dev(host);
- } else if (dev_is_pci(uport)) {
- pdev = to_pci_dev(uport);
- }
-
if (!pdev)
return;
@@ -591,6 +578,7 @@ void read_cdat_data(struct cxl_port *port)
CXL_DOE_PROTOCOL_TABLE_ACCESS);
if (!doe_mb) {
dev_dbg(dev, "No CDAT mailbox\n");
+ pci_dev_put(pdev);
return;
}
@@ -598,6 +586,7 @@ void read_cdat_data(struct cxl_port *port)
if (cxl_cdat_get_length(dev, doe_mb, &length)) {
dev_dbg(dev, "No CDAT length\n");
+ pci_dev_put(pdev);
return;
}
@@ -625,11 +614,13 @@ void read_cdat_data(struct cxl_port *port)
port->cdat.table = buf->data;
port->cdat.length = length;
+ pci_dev_put(pdev);
return;
err:
/* Don't leave table data allocated on error */
devm_kfree(dev, buf);
dev_err(dev, "Failed to read/validate CDAT.\n");
+ pci_dev_put(pdev);
}
EXPORT_SYMBOL_NS_GPL(read_cdat_data, "CXL");
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 625e4aa427db..5dc2815d82d8 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -34,6 +34,32 @@
static DEFINE_IDA(cxl_port_ida);
static DEFINE_XARRAY(cxl_root_buses);
+/**
+ * cxl_port_get_uport_pci_dev - get the PCI device for a port's upstream device
+ * @port: CXL port to map to a PCI device
+ *
+ * Return: A referenced PCI device, or NULL if the upstream device is not PCI.
+ * The caller must release the returned reference with pci_dev_put().
+ */
+struct pci_dev *cxl_port_get_uport_pci_dev(struct cxl_port *port)
+{
+ struct device *uport = port->uport_dev;
+ struct device *host;
+
+ if (is_cxl_memdev(uport)) {
+ struct cxl_memdev *cxlmd = to_cxl_memdev(uport);
+
+ host = cxlmd->dev.parent;
+ } else {
+ host = uport;
+ }
+
+ if (!host || !dev_is_pci(host))
+ return NULL;
+
+ return pci_dev_get(to_pci_dev(host));
+}
+
/*
* The terminal device in PCI is NULL and @platform_bus
* for platform devices (for cxl_test)
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 03/16] cxl: Move decoder declarations to shared header
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 01/16] cxl: Drop stale decoder interleave limit comment Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 02/16] cxl: Share CXL port upstream PCI device lookup Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 04/16] cxl: Embed decoder configuration in a standalone structure Srirangan Madhavan
` (12 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan,
Jonathan Cameron
Move the common decoder declarations to include/cxl/cxl.h for use by
shared decoder settings. Preserve their layout and documentation.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
---
drivers/cxl/cxl.h | 37 -------------------------------------
include/cxl/cxl.h | 41 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 40 insertions(+), 38 deletions(-)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 9e0500d56866..44ff3334648c 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -264,45 +264,8 @@ int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
#define CXL_DECODER_F_NORMALIZED_ADDRESSING BIT(6)
#define CXL_DECODER_F_RESET_MASK (CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK)
-enum cxl_decoder_type {
- CXL_DECODER_DEVMEM = 2,
- CXL_DECODER_HOSTONLYMEM = 3,
-};
-
-#define CXL_DECODER_MAX_INTERLEAVE 16
-
#define CXL_QOS_CLASS_INVALID -1
-/**
- * struct cxl_decoder - Common CXL HDM Decoder Attributes
- * @dev: this decoder's device
- * @id: kernel device name id
- * @hpa_range: Host physical address range mapped by this decoder
- * @interleave_ways: number of cxl_dports in this decode
- * @interleave_granularity: data stride per dport
- * @target_type: accelerator vs expander (type2 vs type3) selector
- * @region: currently assigned region for this decoder
- * @flags: memory type capabilities and locking
- * @target_map: cached copy of hardware port-id list, available at init
- * before all @dport objects have been instantiated. While
- * dport id is 8bit, CFMWS interleave targets are 32bits.
- * @commit: device/decoder-type specific callback to commit settings to hw
- * @reset: device/decoder-type specific callback to reset hw settings
-*/
-struct cxl_decoder {
- struct device dev;
- int id;
- struct range hpa_range;
- int interleave_ways;
- int interleave_granularity;
- enum cxl_decoder_type target_type;
- struct cxl_region *region;
- unsigned long flags;
- u32 target_map[CXL_DECODER_MAX_INTERLEAVE];
- int (*commit)(struct cxl_decoder *cxld);
- void (*reset)(struct cxl_decoder *cxld);
-};
-
/*
* Track whether this decoder is free for userspace provisioning, reserved for
* region autodiscovery, whether it is started connecting (awaiting other
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 802b143de83d..69941f7fdb76 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -5,8 +5,10 @@
#ifndef __CXL_CXL_H__
#define __CXL_CXL_H__
+#include <linux/device.h>
#include <linux/node.h>
#include <linux/ioport.h>
+#include <linux/range.h>
#include <cxl/mailbox.h>
/**
@@ -23,7 +25,44 @@ enum cxl_devtype {
CXL_DEVTYPE_CLASSMEM,
};
-struct device;
+struct cxl_region;
+
+enum cxl_decoder_type {
+ CXL_DECODER_DEVMEM = 2,
+ CXL_DECODER_HOSTONLYMEM = 3,
+};
+
+#define CXL_DECODER_MAX_INTERLEAVE 16
+
+/**
+ * struct cxl_decoder - Common CXL HDM Decoder Attributes
+ * @dev: this decoder's device
+ * @id: kernel device name id
+ * @hpa_range: Host physical address range mapped by this decoder
+ * @interleave_ways: number of cxl_dports in this decode
+ * @interleave_granularity: data stride per dport
+ * @target_type: accelerator vs expander (type2 vs type3) selector
+ * @region: currently assigned region for this decoder
+ * @flags: memory type capabilities and locking
+ * @target_map: cached copy of hardware port-id list, available at init
+ * before all @dport objects have been instantiated. While
+ * dport id is 8bit, CFMWS interleave targets are 32bits.
+ * @commit: device/decoder-type specific callback to commit settings to hw
+ * @reset: device/decoder-type specific callback to reset hw settings
+*/
+struct cxl_decoder {
+ struct device dev;
+ int id;
+ struct range hpa_range;
+ int interleave_ways;
+ int interleave_granularity;
+ enum cxl_decoder_type target_type;
+ struct cxl_region *region;
+ unsigned long flags;
+ u32 target_map[CXL_DECODER_MAX_INTERLEAVE];
+ int (*commit)(struct cxl_decoder *cxld);
+ void (*reset)(struct cxl_decoder *cxld);
+};
/*
* Using struct_group() allows for per register-block-type helper routines,
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 04/16] cxl: Embed decoder configuration in a standalone structure
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (2 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 03/16] cxl: Move decoder declarations to shared header Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 05/16] cxl: Introduce reusable HDM decoder settings Srirangan Madhavan
` (11 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Define cxl_decoder_config independently and embed it in cxl_decoder. Update
decoder field accesses without changing behavior, so reset snapshots can
reuse the configuration type without struct_group_tagged().
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/acpi.c | 26 +++---
drivers/cxl/core/atl.c | 4 +-
drivers/cxl/core/hdm.c | 114 ++++++++++++-------------
drivers/cxl/core/pci.c | 8 +-
drivers/cxl/core/port.c | 42 +++++-----
drivers/cxl/core/region.c | 102 +++++++++++-----------
drivers/cxl/cxl.h | 2 +-
drivers/cxl/pci.c | 2 +-
drivers/cxl/port.c | 4 +-
include/cxl/cxl.h | 26 ++++--
tools/testing/cxl/test/cxl.c | 158 +++++++++++++++++------------------
11 files changed, 246 insertions(+), 242 deletions(-)
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 3b818adbd38b..692a4e067678 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -109,16 +109,16 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
return rc;
/* Does this CXIMS entry apply to the given CXL Window? */
- if (hbig != cxld->interleave_granularity)
+ if (hbig != cxld->config.interleave_granularity)
return 0;
/* IW 1,3 do not use xormaps and skip this parsing entirely */
- if (is_power_of_2(cxld->interleave_ways))
+ if (is_power_of_2(cxld->config.interleave_ways))
/* 2, 4, 8, 16 way */
- nr_maps = ilog2(cxld->interleave_ways);
+ nr_maps = ilog2(cxld->config.interleave_ways);
else
/* 6, 12 way */
- nr_maps = ilog2(cxld->interleave_ways / 3);
+ nr_maps = ilog2(cxld->config.interleave_ways / 3);
if (cxims->nr_xormaps < nr_maps) {
dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n",
@@ -363,7 +363,7 @@ static int add_or_reset_cxl_resource(struct resource *parent, struct resource *r
static void cxl_setup_extended_linear_cache(struct cxl_root_decoder *cxlrd)
{
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
- struct range *hpa = &cxld->hpa_range;
+ struct range *hpa = &cxld->config.hpa_range;
resource_size_t size = range_len(hpa);
resource_size_t start = hpa->start;
resource_size_t cache_size;
@@ -436,13 +436,13 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
return PTR_ERR(cxlrd);
cxld = &cxlrd->cxlsd.cxld;
- cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->hpa_range = (struct range) {
+ cxld->config.flags = cfmws_to_decoder_flags(cfmws->restrictions);
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.hpa_range = (struct range) {
.start = cfmws->base_hpa,
.end = cfmws->base_hpa + cfmws->window_size - 1,
};
- cxld->interleave_ways = ways;
+ cxld->config.interleave_ways = ways;
for (i = 0; i < ways; i++)
cxld->target_map[i] = cfmws->interleave_targets[i];
/*
@@ -451,7 +451,7 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
*/
if (ways == 1)
ig = CXL_DECODER_MIN_GRANULARITY;
- cxld->interleave_granularity = ig;
+ cxld->config.interleave_granularity = ig;
if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
if (ways != 1 && ways != 3) {
@@ -752,7 +752,7 @@ static int add_root_nvdimm_bridge(struct device *match, void *data)
return 0;
cxld = to_cxl_decoder(match);
- if (!(cxld->flags & CXL_DECODER_F_PMEM))
+ if (!(cxld->config.flags & CXL_DECODER_F_PMEM))
return 0;
cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port);
@@ -869,8 +869,8 @@ static int pair_cxl_resource(struct device *dev, void *data)
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct resource res = {
- .start = cxld->hpa_range.start,
- .end = cxld->hpa_range.end,
+ .start = cxld->config.hpa_range.start,
+ .end = cxld->config.hpa_range.end,
.flags = IORESOURCE_MEM,
};
diff --git a/drivers/cxl/core/atl.c b/drivers/cxl/core/atl.c
index 310668786189..07ce7c50c47a 100644
--- a/drivers/cxl/core/atl.c
+++ b/drivers/cxl/core/atl.c
@@ -172,8 +172,8 @@ static int cxl_prm_setup_root(struct cxl_root *cxl_root, void *data)
*
* Indicate that Normalized Addressing is enabled.
*/
- cxld->flags |= CXL_DECODER_F_LOCK;
- cxld->flags |= CXL_DECODER_F_NORMALIZED_ADDRESSING;
+ cxld->config.flags |= CXL_DECODER_F_LOCK;
+ cxld->config.flags |= CXL_DECODER_F_NORMALIZED_ADDRESSING;
ctx->hpa_range = hpa_range;
ctx->interleave_ways = ways;
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 39fe283cbc74..9e05032a5426 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -384,11 +384,11 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
if (cxled->dpa_res) {
dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
- port->id, cxled->cxld.id, cxled->dpa_res);
+ port->id, cxled->cxld.config.id, cxled->dpa_res);
return -EBUSY;
}
- if (port->hdm_end + 1 != cxled->cxld.id) {
+ if (port->hdm_end + 1 != cxled->cxld.config.id) {
/*
* Assumes alloc and commit order is always in hardware instance
* order per expectations from 8.2.5.12.20 Committing Decoder
@@ -396,7 +396,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
* decoder[m+1] commit start.
*/
dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id,
- cxled->cxld.id, port->id, port->hdm_end + 1);
+ cxled->cxld.config.id, port->id, port->hdm_end + 1);
return -EBUSY;
}
@@ -409,7 +409,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
dev_name(&cxled->cxld.dev));
if (IS_ERR(res)) {
dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n",
- port->id, cxled->cxld.id);
+ port->id, cxled->cxld.config.id);
if (skipped)
release_skip(cxlds, base - skipped, skipped);
return PTR_ERR(res);
@@ -432,7 +432,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
/* Empty decoders may not be contained by a partition boundary */
if (cxled->part < 0 && resource_size(res))
dev_warn(dev, "decoder%d.%d: %pr does not map any partition\n",
- port->id, cxled->cxld.id, res);
+ port->id, cxled->cxld.config.id, res);
port->hdm_end++;
get_device(&cxled->cxld.dev);
@@ -580,11 +580,11 @@ int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
dev_name(&cxled->cxld.region->dev));
return -EBUSY;
}
- if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
+ if (cxled->cxld.config.flags & CXL_DECODER_F_ENABLE) {
dev_dbg(dev, "decoder enabled\n");
return -EBUSY;
}
- if (cxled->cxld.id != port->hdm_end) {
+ if (cxled->cxld.config.id != port->hdm_end) {
dev_dbg(dev, "expected decoder%d.%d\n", port->id,
port->hdm_end);
return -EBUSY;
@@ -603,7 +603,7 @@ int cxl_dpa_set_part(struct cxl_endpoint_decoder *cxled,
int part;
guard(rwsem_write)(&cxl_rwsem.dpa);
- if (cxled->cxld.flags & CXL_DECODER_F_ENABLE)
+ if (cxled->cxld.config.flags & CXL_DECODER_F_ENABLE)
return -EBUSY;
for (part = 0; part < cxlds->nr_partitions; part++)
@@ -641,7 +641,7 @@ static int __cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, u64 size)
return -EBUSY;
}
- if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
+ if (cxled->cxld.config.flags & CXL_DECODER_F_ENABLE) {
dev_dbg(dev, "decoder enabled\n");
return -EBUSY;
}
@@ -716,12 +716,12 @@ static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
* Input validation ensures these warns never fire, but otherwise
* suppress unititalized variable usage warnings.
*/
- if (WARN_ONCE(ways_to_eiw(cxld->interleave_ways, &eiw),
- "invalid interleave_ways: %d\n", cxld->interleave_ways))
+ if (WARN_ONCE(ways_to_eiw(cxld->config.interleave_ways, &eiw),
+ "invalid interleave_ways: %d\n", cxld->config.interleave_ways))
return;
- if (WARN_ONCE(granularity_to_eig(cxld->interleave_granularity, &eig),
+ if (WARN_ONCE(granularity_to_eig(cxld->config.interleave_granularity, &eig),
"invalid interleave_granularity: %d\n",
- cxld->interleave_granularity))
+ cxld->config.interleave_granularity))
return;
u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
@@ -732,14 +732,14 @@ static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
{
u32p_replace_bits(ctrl,
- !!(cxld->target_type == CXL_DECODER_HOSTONLYMEM),
+ !!(cxld->config.target_type == CXL_DECODER_HOSTONLYMEM),
CXL_HDM_DECODER0_CTRL_HOSTONLY);
}
static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
{
struct cxl_dport **t = &cxlsd->target[0];
- int ways = cxlsd->cxld.interleave_ways;
+ int ways = cxlsd->cxld.config.interleave_ways;
*tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id);
if (ways > 1)
@@ -786,16 +786,16 @@ static int cxld_await_commit(void __iomem *hdm, int id)
static void setup_hw_decoder(struct cxl_decoder *cxld, void __iomem *hdm)
{
- int id = cxld->id;
+ int id = cxld->config.id;
u64 base, size;
u32 ctrl;
/* common decoder settings */
- ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id));
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->config.id));
cxld_set_interleave(cxld, &ctrl);
cxld_set_type(cxld, &ctrl);
- base = cxld->hpa_range.start;
- size = range_len(&cxld->hpa_range);
+ base = cxld->config.hpa_range.start;
+ size = range_len(&cxld->config.hpa_range);
writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
@@ -830,9 +830,9 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
- int id = cxld->id, rc;
+ int id = cxld->config.id, rc;
- if (cxld->flags & CXL_DECODER_F_ENABLE)
+ if (cxld->config.flags & CXL_DECODER_F_ENABLE)
return 0;
if (cxl_num_decoders_committed(port) != id) {
@@ -865,14 +865,14 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
scoped_guard(rwsem_read, &cxl_rwsem.dpa)
setup_hw_decoder(cxld, hdm);
- rc = cxld_await_commit(hdm, cxld->id);
+ rc = cxld_await_commit(hdm, cxld->config.id);
if (rc) {
dev_dbg(&port->dev, "%s: error %d committing decoder\n",
dev_name(&cxld->dev), rc);
return rc;
}
port->commit_end++;
- cxld->flags |= CXL_DECODER_F_ENABLE;
+ cxld->config.flags |= CXL_DECODER_F_ENABLE;
return 0;
}
@@ -886,8 +886,8 @@ static int commit_reap(struct device *dev, void *data)
return 0;
cxld = to_cxl_decoder(dev);
- if (port->commit_end == cxld->id &&
- ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
+ if (port->commit_end == cxld->config.id &&
+ ((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0)) {
port->commit_end--;
dev_dbg(&port->dev, "reap: %s commit_end: %d\n",
dev_name(&cxld->dev), port->commit_end);
@@ -919,13 +919,13 @@ static void cxl_decoder_reset(struct cxl_decoder *cxld)
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
- int id = cxld->id;
+ int id = cxld->config.id;
u32 ctrl;
- if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
+ if ((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0)
return;
- if (cxld->flags & CXL_DECODER_F_LOCK)
+ if (cxld->config.flags & CXL_DECODER_F_LOCK)
return;
if (port->commit_end == id)
@@ -944,7 +944,7 @@ static void cxl_decoder_reset(struct cxl_decoder *cxld)
writel(0, hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
- cxld->flags &= ~CXL_DECODER_F_ENABLE;
+ cxld->config.flags &= ~CXL_DECODER_F_ENABLE;
/* Userspace is now responsible for reconfiguring this decoder */
if (is_endpoint_decoder(&cxld->dev)) {
@@ -971,23 +971,23 @@ static int cxl_setup_hdm_decoder_from_dvsec(
if (!len)
return -ENOENT;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
cxld->commit = NULL;
cxld->reset = NULL;
- cxld->hpa_range = info->dvsec_range[which];
+ cxld->config.hpa_range = info->dvsec_range[which];
/*
* Set the emulated decoder as locked pending additional support to
* change the range registers at run time.
*/
- cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
- port->commit_end = cxld->id;
+ cxld->config.flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
+ port->commit_end = cxld->config.id;
rc = devm_cxl_dpa_reserve(cxled, *dpa_base, len, 0);
if (rc) {
dev_err(&port->dev,
"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx: %d\n",
- port->id, cxld->id, *dpa_base, *dpa_base + len - 1, rc);
+ port->id, cxld->config.id, *dpa_base, *dpa_base + len - 1, rc);
return rc;
}
*dpa_base += len;
@@ -1030,36 +1030,36 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
size = 0;
if (base == U64_MAX || size == U64_MAX) {
dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",
- port->id, cxld->id);
+ port->id, cxld->config.id);
return -ENXIO;
}
if (info)
cxled = to_cxl_endpoint_decoder(&cxld->dev);
- cxld->hpa_range = (struct range) {
+ cxld->config.hpa_range = (struct range) {
.start = base,
.end = base + size - 1,
};
/* decoders are enabled if committed */
if (committed) {
- cxld->flags |= CXL_DECODER_F_ENABLE;
+ cxld->config.flags |= CXL_DECODER_F_ENABLE;
if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
- cxld->flags |= CXL_DECODER_F_LOCK;
+ cxld->config.flags |= CXL_DECODER_F_LOCK;
if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
else
- cxld->target_type = CXL_DECODER_DEVMEM;
+ cxld->config.target_type = CXL_DECODER_DEVMEM;
guard(rwsem_write)(&cxl_rwsem.region);
- if (cxld->id != cxl_num_decoders_committed(port)) {
+ if (cxld->config.id != cxl_num_decoders_committed(port)) {
dev_warn(&port->dev,
"decoder%d.%d: Committed out of order\n",
- port->id, cxld->id);
+ port->id, cxld->config.id);
return -ENXIO;
}
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
} else {
if (cxled) {
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
@@ -1070,46 +1070,46 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
* more precision.
*/
if (cxlds->type == CXL_DEVTYPE_CLASSMEM)
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
else
- cxld->target_type = CXL_DECODER_DEVMEM;
+ cxld->config.target_type = CXL_DECODER_DEVMEM;
} else {
/* To be overridden by region type at commit time */
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
}
if (!FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl) &&
- cxld->target_type == CXL_DECODER_HOSTONLYMEM) {
+ cxld->config.target_type == CXL_DECODER_HOSTONLYMEM) {
ctrl |= CXL_HDM_DECODER0_CTRL_HOSTONLY;
writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
}
}
rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
- &cxld->interleave_ways);
+ &cxld->config.interleave_ways);
if (rc) {
dev_warn(&port->dev,
"decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",
- port->id, cxld->id, ctrl);
+ port->id, cxld->config.id, ctrl);
return rc;
}
rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
- &cxld->interleave_granularity);
+ &cxld->config.interleave_granularity);
if (rc) {
dev_warn(&port->dev,
"decoder%d.%d: Invalid interleave granularity (ctrl: %#x)\n",
- port->id, cxld->id, ctrl);
+ port->id, cxld->config.id, ctrl);
return rc;
}
dev_dbg(&port->dev, "decoder%d.%d: range: %#llx-%#llx iw: %d ig: %d\n",
- port->id, cxld->id, cxld->hpa_range.start, cxld->hpa_range.end,
- cxld->interleave_ways, cxld->interleave_granularity);
+ port->id, cxld->config.id, cxld->config.hpa_range.start, cxld->config.hpa_range.end,
+ cxld->config.interleave_ways, cxld->config.interleave_granularity);
if (!cxled) {
lo = readl(hdm + CXL_HDM_DECODER0_TL_LOW(which));
hi = readl(hdm + CXL_HDM_DECODER0_TL_HIGH(which));
target_list.value = (hi << 32) + lo;
- for (i = 0; i < cxld->interleave_ways; i++)
+ for (i = 0; i < cxld->config.interleave_ways; i++)
cxld->target_map[i] = target_list.target_id[i];
return 0;
@@ -1118,11 +1118,11 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
if (!committed)
return 0;
- dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder);
+ dpa_size = div_u64_rem(size, cxld->config.interleave_ways, &remainder);
if (remainder) {
dev_err(&port->dev,
"decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n",
- port->id, cxld->id, size, cxld->interleave_ways);
+ port->id, cxld->config.id, size, cxld->config.interleave_ways);
return -ENXIO;
}
lo = readl(hdm + CXL_HDM_DECODER0_SKIP_LOW(which));
@@ -1132,7 +1132,7 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
if (rc) {
dev_err(&port->dev,
"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx: %d\n",
- port->id, cxld->id, *dpa_base,
+ port->id, cxld->config.id, *dpa_base,
*dpa_base + dpa_size + skip - 1, rc);
return rc;
}
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 99c8b02d42e5..9411694b93b3 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -231,10 +231,10 @@ static int dvsec_range_allowed(struct device *dev, const void *arg)
cxld = to_cxl_decoder(dev);
- if (!(cxld->flags & CXL_DECODER_F_RAM))
+ if (!(cxld->config.flags & CXL_DECODER_F_RAM))
return 0;
- return range_contains(&cxld->hpa_range, dev_range);
+ return range_contains(&cxld->config.hpa_range, dev_range);
}
static void disable_hdm(void *_cxlhdm)
@@ -671,12 +671,12 @@ static int __cxl_endpoint_decoder_reset_detected(struct device *dev, void *data)
return 0;
cxld = to_cxl_decoder(dev);
- if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
+ if ((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0)
return 0;
cxlhdm = dev_get_drvdata(&port->dev);
hdm = cxlhdm->regs.hdm_decoder;
- ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id));
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->config.id));
return !FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl);
}
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 5dc2815d82d8..84374873f3d0 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -129,7 +129,7 @@ static ssize_t start_show(struct device *dev, struct device_attribute *attr,
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- return sysfs_emit(buf, "%#llx\n", cxld->hpa_range.start);
+ return sysfs_emit(buf, "%#llx\n", cxld->config.hpa_range.start);
}
static DEVICE_ATTR_ADMIN_RO(start);
@@ -138,7 +138,7 @@ static ssize_t size_show(struct device *dev, struct device_attribute *attr,
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- return sysfs_emit(buf, "%#llx\n", range_len(&cxld->hpa_range));
+ return sysfs_emit(buf, "%#llx\n", range_len(&cxld->config.hpa_range));
}
static DEVICE_ATTR_RO(size);
@@ -149,7 +149,7 @@ static ssize_t name##_show(struct device *dev, \
struct cxl_decoder *cxld = to_cxl_decoder(dev); \
\
return sysfs_emit(buf, "%s\n", \
- (cxld->flags & (flag)) ? "1" : "0"); \
+ (cxld->config.flags & (flag)) ? "1" : "0"); \
} \
static DEVICE_ATTR_RO(name)
@@ -164,7 +164,7 @@ static ssize_t target_type_show(struct device *dev,
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- switch (cxld->target_type) {
+ switch (cxld->config.target_type) {
case CXL_DECODER_DEVMEM:
return sysfs_emit(buf, "accelerator\n");
case CXL_DECODER_HOSTONLYMEM:
@@ -180,14 +180,14 @@ static ssize_t emit_target_list(struct cxl_switch_decoder *cxlsd, char *buf)
ssize_t offset = 0;
int i, rc = 0;
- for (i = 0; i < cxld->interleave_ways; i++) {
+ for (i = 0; i < cxld->config.interleave_ways; i++) {
struct cxl_dport *dport = cxlsd->target[i];
struct cxl_dport *next = NULL;
if (!dport)
break;
- if (i + 1 < cxld->interleave_ways)
+ if (i + 1 < cxld->config.interleave_ways)
next = cxlsd->target[i + 1];
rc = sysfs_emit_at(buf, offset, "%d%s", dport->port_id,
next ? "," : "");
@@ -314,7 +314,7 @@ static ssize_t interleave_granularity_show(struct device *dev,
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- return sysfs_emit(buf, "%d\n", cxld->interleave_granularity);
+ return sysfs_emit(buf, "%d\n", cxld->config.interleave_granularity);
}
static DEVICE_ATTR_RO(interleave_granularity);
@@ -324,7 +324,7 @@ static ssize_t interleave_ways_show(struct device *dev,
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- return sysfs_emit(buf, "%d\n", cxld->interleave_ways);
+ return sysfs_emit(buf, "%d\n", cxld->config.interleave_ways);
}
static DEVICE_ATTR_RO(interleave_ways);
@@ -368,14 +368,14 @@ static bool can_create_pmem(struct cxl_root_decoder *cxlrd)
{
unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_PMEM;
- return (cxlrd->cxlsd.cxld.flags & flags) == flags;
+ return (cxlrd->cxlsd.cxld.config.flags & flags) == flags;
}
static bool can_create_ram(struct cxl_root_decoder *cxlrd)
{
unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_RAM;
- return (cxlrd->cxlsd.cxld.flags & flags) == flags;
+ return (cxlrd->cxlsd.cxld.config.flags & flags) == flags;
}
static umode_t cxl_root_decoder_visible(struct kobject *kobj, struct attribute *a, int n)
@@ -450,7 +450,7 @@ static void __cxl_decoder_release(struct cxl_decoder *cxld)
{
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
- ida_free(&port->decoder_ida, cxld->id);
+ ida_free(&port->decoder_ida, cxld->config.id);
put_device(&port->dev);
}
@@ -1646,7 +1646,7 @@ static int update_decoder_targets(struct device *dev, void *data)
cxld = &cxlsd->cxld;
guard(rwsem_write)(&cxl_rwsem.region);
- for (i = 0; i < cxld->interleave_ways; i++) {
+ for (i = 0; i < cxld->config.interleave_ways; i++) {
if (cxld->target_map[i] == dport->port_id) {
cxlsd->target[i] = dport;
dev_dbg(dev, "dport%d found in target list, index %d\n",
@@ -1952,7 +1952,7 @@ static int decoder_populate_targets(struct cxl_switch_decoder *cxlsd,
return 0;
guard(rwsem_write)(&cxl_rwsem.region);
- for (i = 0; i < cxlsd->cxld.interleave_ways; i++) {
+ for (i = 0; i < cxlsd->cxld.config.interleave_ways; i++) {
struct cxl_dport *dport = find_dport(port, cxld->target_map[i]);
if (!dport) {
@@ -1988,7 +1988,7 @@ static int cxl_decoder_init(struct cxl_port *port, struct cxl_decoder *cxld)
/* need parent to stick around to release the id */
get_device(&port->dev);
- cxld->id = rc;
+ cxld->config.id = rc;
dev = &cxld->dev;
device_initialize(dev);
@@ -1998,10 +1998,10 @@ static int cxl_decoder_init(struct cxl_port *port, struct cxl_decoder *cxld)
dev->bus = &cxl_bus_type;
/* Pre initialize an "empty" decoder */
- cxld->interleave_ways = 1;
- cxld->interleave_granularity = PAGE_SIZE;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->hpa_range = (struct range) {
+ cxld->config.interleave_ways = 1;
+ cxld->config.interleave_granularity = PAGE_SIZE;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.hpa_range = (struct range) {
.start = 0,
.end = -1,
};
@@ -2172,7 +2172,7 @@ int cxl_decoder_add_locked(struct cxl_decoder *cxld)
if (WARN_ON_ONCE(IS_ERR(cxld)))
return PTR_ERR(cxld);
- if (cxld->interleave_ways < 1)
+ if (cxld->config.interleave_ways < 1)
return -EINVAL;
dev = &cxld->dev;
@@ -2182,14 +2182,14 @@ int cxl_decoder_add_locked(struct cxl_decoder *cxld)
struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);
rc = decoder_populate_targets(cxlsd, port);
- if (rc && (cxld->flags & CXL_DECODER_F_ENABLE)) {
+ if (rc && (cxld->config.flags & CXL_DECODER_F_ENABLE)) {
dev_err(&port->dev,
"Failed to populate active decoder targets\n");
return rc;
}
}
- rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id);
+ rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->config.id);
if (rc)
return rc;
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index bb51e67f25f5..8cfc06df3134 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -502,8 +502,8 @@ static int set_interleave_ways(struct cxl_region *cxlr, int val)
* Even for x3, x6, and x12 interleaves the region interleave must be a
* power of 2 multiple of the host bridge interleave.
*/
- if (!is_power_of_2(val / cxld->interleave_ways) ||
- (val % cxld->interleave_ways)) {
+ if (!is_power_of_2(val / cxld->config.interleave_ways) ||
+ (val % cxld->config.interleave_ways)) {
dev_dbg(&cxlr->dev, "invalid interleave: %d\n", val);
return -EINVAL;
}
@@ -580,7 +580,7 @@ static int set_interleave_granularity(struct cxl_region *cxlr, int val)
* with a granularity greater than the root interleave result in invalid
* DPA translations (invalid to support).
*/
- if (cxld->interleave_ways > 1 && val != cxld->interleave_granularity)
+ if (cxld->config.interleave_ways > 1 && val != cxld->config.interleave_granularity)
return -EINVAL;
lockdep_assert_held_write(&cxl_rwsem.region);
@@ -880,7 +880,7 @@ static int check_commit_order(struct device *dev, void *data)
* order shutdown has occurred, block further allocations until
* that is resolved
*/
- if (((cxld->flags & CXL_DECODER_F_ENABLE) == 0))
+ if (((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0))
return -EBUSY;
return 0;
}
@@ -896,7 +896,7 @@ static int match_free_decoder(struct device *dev, const void *data)
cxld = to_cxl_decoder(dev);
- if (cxld->id != port->commit_end + 1)
+ if (cxld->config.id != port->commit_end + 1)
return 0;
if (cxld->region) {
@@ -942,7 +942,7 @@ static int match_auto_decoder(struct device *dev, const void *data)
return 0;
cxld = to_cxl_decoder(dev);
- r = &cxld->hpa_range;
+ r = &cxld->config.hpa_range;
if (spa_maps_hpa(p, r))
return 1;
@@ -1003,10 +1003,10 @@ static bool auto_order_ok(struct cxl_port *port, struct cxl_region *cxlr_iter,
* starting address has the lesser id.
*/
dev_dbg(&cxld->dev, "check for HPA violation %s:%d < %s:%d\n",
- dev_name(&cxld->dev), cxld->id,
- dev_name(&cxld_iter->dev), cxld_iter->id);
+ dev_name(&cxld->dev), cxld->config.id,
+ dev_name(&cxld_iter->dev), cxld_iter->config.id);
- if (cxld_iter->id > cxld->id)
+ if (cxld_iter->config.id > cxld->config.id)
return true;
return false;
@@ -1137,11 +1137,11 @@ static int cxl_rr_assign_decoder(struct cxl_port *port, struct cxl_region *cxlr,
*/
dev_WARN_ONCE(&cxlr->dev,
port == cxled_to_port(cxled) &&
- cxld->target_type != cxlr->type,
+ cxld->config.target_type != cxlr->type,
"%s:%s mismatch decoder type %d -> %d\n",
dev_name(&cxled_to_memdev(cxled)->dev),
- dev_name(&cxld->dev), cxld->target_type, cxlr->type);
- cxld->target_type = cxlr->type;
+ dev_name(&cxld->dev), cxld->config.target_type, cxlr->type);
+ cxld->config.target_type = cxlr->type;
cxl_rr->decoder = cxld;
return 0;
}
@@ -1162,12 +1162,12 @@ static void cxl_region_setup_flags(struct cxl_region *cxlr,
set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
}
- if (cxld->flags & CXL_DECODER_F_LOCK) {
+ if (cxld->config.flags & CXL_DECODER_F_LOCK) {
set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
}
- if (cxld->flags & CXL_DECODER_F_NORMALIZED_ADDRESSING)
+ if (cxld->config.flags & CXL_DECODER_F_NORMALIZED_ADDRESSING)
set_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags);
}
@@ -1483,7 +1483,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
distance *= cxl_rr_iter->nr_targets;
iter = to_cxl_port(iter->dev.parent);
} while (!is_cxl_root(iter));
- distance *= cxlrd->cxlsd.cxld.interleave_ways;
+ distance *= cxlrd->cxlsd.cxld.config.interleave_ways;
for (i = 0; i < cxl_rr->nr_targets_set; i++)
if (ep->dport == cxlsd->target[i]) {
@@ -1505,7 +1505,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
* root IG != region IG.
*/
parent_ig = p->interleave_granularity;
- parent_iw = cxlrd->cxlsd.cxld.interleave_ways;
+ parent_iw = cxlrd->cxlsd.cxld.config.interleave_ways;
/*
* For purposes of address bit routing, use power-of-2 math for
* switch ports.
@@ -1518,8 +1518,8 @@ static int cxl_port_setup_targets(struct cxl_port *port,
parent_rr = cxl_rr_load(parent_port, cxlr);
parent_cxld = parent_rr->decoder;
- parent_ig = parent_cxld->interleave_granularity;
- parent_iw = parent_cxld->interleave_ways;
+ parent_ig = parent_cxld->config.interleave_granularity;
+ parent_iw = parent_cxld->config.interleave_ways;
}
rc = granularity_to_eig(parent_ig, &peig);
@@ -1575,10 +1575,10 @@ static int cxl_port_setup_targets(struct cxl_port *port,
}
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
- if (cxld->interleave_ways != iw ||
- (iw > 1 && cxld->interleave_granularity != ig) ||
- !spa_maps_hpa(p, &cxld->hpa_range) ||
- ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
+ if (cxld->config.interleave_ways != iw ||
+ (iw > 1 && cxld->config.interleave_granularity != ig) ||
+ !spa_maps_hpa(p, &cxld->config.hpa_range) ||
+ ((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0)) {
dev_err(&cxlr->dev,
"%s:%s %s expected iw: %d ig: %d %pr\n",
dev_name(port->uport_dev), dev_name(&port->dev),
@@ -1586,10 +1586,10 @@ static int cxl_port_setup_targets(struct cxl_port *port,
dev_err(&cxlr->dev,
"%s:%s %s got iw: %d ig: %d state: %s %#llx:%#llx\n",
dev_name(port->uport_dev), dev_name(&port->dev),
- __func__, cxld->interleave_ways,
- cxld->interleave_granularity,
- str_enabled_disabled(cxld->flags & CXL_DECODER_F_ENABLE),
- cxld->hpa_range.start, cxld->hpa_range.end);
+ __func__, cxld->config.interleave_ways,
+ cxld->config.interleave_granularity,
+ str_enabled_disabled(cxld->config.flags & CXL_DECODER_F_ENABLE),
+ cxld->config.hpa_range.start, cxld->config.hpa_range.end);
return -ENXIO;
}
} else {
@@ -1602,9 +1602,9 @@ static int cxl_port_setup_targets(struct cxl_port *port,
return rc;
}
- cxld->interleave_ways = iw;
- cxld->interleave_granularity = ig;
- cxld->hpa_range = (struct range) {
+ cxld->config.interleave_ways = iw;
+ cxld->config.interleave_granularity = ig;
+ cxld->config.hpa_range = (struct range) {
.start = p->res->start,
.end = p->res->end,
};
@@ -1657,7 +1657,7 @@ static void cxl_port_reset_targets(struct cxl_port *port,
cxl_rr->nr_targets_set = 0;
cxld = cxl_rr->decoder;
- cxld->hpa_range = (struct range) {
+ cxld->config.hpa_range = (struct range) {
.start = 0,
.end = -1,
};
@@ -1804,7 +1804,7 @@ static int cxl_region_attach_position(struct cxl_region *cxlr,
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd;
struct cxl_decoder *cxld = &cxlsd->cxld;
- int iw = cxld->interleave_ways;
+ int iw = cxld->config.interleave_ways;
struct cxl_port *iter;
int rc;
@@ -1902,7 +1902,7 @@ static int match_switch_decoder_by_range(struct device *dev,
return 0;
cxlsd = to_cxl_switch_decoder(dev);
- r1 = &cxlsd->cxld.hpa_range;
+ r1 = &cxlsd->cxld.config.hpa_range;
if (is_root_decoder(dev))
return range_contains(r1, r2);
@@ -1929,7 +1929,7 @@ static int find_pos_and_ways(struct cxl_port *port, struct range *range,
return rc;
}
cxlsd = to_cxl_switch_decoder(dev);
- *ways = cxlsd->cxld.interleave_ways;
+ *ways = cxlsd->cxld.config.interleave_ways;
for (int i = 0; i < *ways; i++) {
if (cxlsd->target[i] == port->parent_dport) {
@@ -2105,10 +2105,10 @@ static int cxl_region_attach(struct cxl_region *cxlr,
return -ENXIO;
}
- if (cxled->cxld.target_type != cxlr->type) {
+ if (cxled->cxld.config.target_type != cxlr->type) {
dev_dbg(&cxlr->dev, "%s:%s type mismatch: %d vs %d\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
- cxled->cxld.target_type, cxlr->type);
+ cxled->cxld.config.target_type, cxlr->type);
return -ENXIO;
}
@@ -2194,9 +2194,9 @@ static int cxl_region_attach(struct cxl_region *cxlr,
cxl_region_shared_upstream_bandwidth_update(cxlr);
}
- cxled->cxld.interleave_ways = p->interleave_ways;
- cxled->cxld.interleave_granularity = p->interleave_granularity;
- cxled->cxld.hpa_range = (struct range) {
+ cxled->cxld.config.interleave_ways = p->interleave_ways;
+ cxled->cxld.config.interleave_granularity = p->interleave_granularity;
+ cxled->cxld.config.hpa_range = (struct range) {
.start = p->res->start,
.end = p->res->end,
};
@@ -2320,7 +2320,7 @@ __cxl_decoder_detach(struct cxl_region *cxlr,
}
p->targets[cxled->pos] = NULL;
p->nr_targets--;
- cxled->cxld.hpa_range = (struct range) {
+ cxled->cxld.config.hpa_range = (struct range) {
.start = 0,
.end = -1,
};
@@ -2992,7 +2992,7 @@ static int poison_by_decoder(struct device *dev, void *arg)
}
/* Iterate until commit_end is reached */
- if (cxled->cxld.id == ctx->port->commit_end) {
+ if (cxled->cxld.config.id == ctx->port->commit_end) {
ctx->offset = cxled->dpa_res->end + 1;
ctx->part = cxled->part;
return 1;
@@ -3315,10 +3315,10 @@ static u64 restore_parent(u64 addr, u64 pos, u64 gran, u64 ways)
static u64 unaligned_dpa_to_hpa(struct cxl_decoder *cxld,
struct cxl_region_params *p, int pos, u64 dpa)
{
- int ways_port = p->interleave_ways / cxld->interleave_ways;
+ int ways_port = p->interleave_ways / cxld->config.interleave_ways;
int gran_port = p->interleave_granularity;
- int gran_hb = cxld->interleave_granularity;
- int ways_hb = cxld->interleave_ways;
+ int gran_hb = cxld->config.interleave_granularity;
+ int ways_hb = cxld->config.interleave_ways;
int pos_port, pos_hb, gran_shift;
u64 hpa_port = 0;
@@ -3365,7 +3365,7 @@ static bool region_is_unaligned_mod3(struct cxl_region *cxlr)
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct cxl_region_params *p = &cxlr->params;
- int hbiw = cxld->interleave_ways;
+ int hbiw = cxld->config.interleave_ways;
u64 rem;
if (is_power_of_2(hbiw))
@@ -3480,8 +3480,8 @@ static int unaligned_region_offset_to_dpa_result(struct cxl_region *cxlr,
* a dpa_offset independent of the target device and then enumerate
* and test that dpa_offset against each candidate endpoint decoder.
*/
- gran = cxld->interleave_granularity;
- interleave_width = gran * cxld->interleave_ways;
+ gran = cxld->config.interleave_granularity;
+ interleave_width = gran * cxld->config.interleave_ways;
interleave_index = div64_u64(offset, interleave_width);
gran_offset = do_div(tmp, gran);
@@ -3581,7 +3581,7 @@ static int match_root_decoder(struct device *dev, const void *data)
return 0;
cxlrd = to_cxl_root_decoder(dev);
- r1 = &cxlrd->cxlsd.cxld.hpa_range;
+ r1 = &cxlrd->cxlsd.cxld.config.hpa_range;
return range_contains(r1, r2);
}
@@ -3786,7 +3786,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
do {
cxlr = __create_region(cxlrd, cxlds->part[part].mode,
atomic_read(&cxlrd->region_id),
- cxled->cxld.target_type);
+ cxled->cxld.config.target_type);
} while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY);
if (IS_ERR(cxlr)) {
@@ -3829,9 +3829,9 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
ctx = (struct cxl_region_context) {
.cxled = cxled,
- .hpa_range = cxled->cxld.hpa_range,
- .interleave_ways = cxled->cxld.interleave_ways,
- .interleave_granularity = cxled->cxld.interleave_granularity,
+ .hpa_range = cxled->cxld.config.hpa_range,
+ .interleave_ways = cxled->cxld.config.interleave_ways,
+ .interleave_granularity = cxled->cxld.config.interleave_granularity,
};
struct cxl_root_decoder *cxlrd __free(put_cxl_root_decoder) =
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 44ff3334648c..688350c7c5fb 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -281,7 +281,7 @@ enum cxl_decoder_state {
* struct cxl_endpoint_decoder - Endpoint / SPA to DPA decoder
* @cxld: base cxl_decoder_object
* @dpa_res: actively claimed DPA span of this decoder
- * @skip: offset into @dpa_res where @cxld.hpa_range maps
+ * @skip: offset into @dpa_res where @cxld.config.hpa_range maps
* @state: autodiscovery state
* @part: partition index this decoder maps
* @pos: interleave position in @cxld.region
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index c7c91e8dc51d..9a0cbcd230b2 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -966,7 +966,7 @@ static int cxl_endpoint_decoder_clear_reset_flags(struct device *dev, void *data
return 0;
cxled = to_cxl_endpoint_decoder(dev);
- cxled->cxld.flags &= ~CXL_DECODER_F_RESET_MASK;
+ cxled->cxld.config.flags &= ~CXL_DECODER_F_RESET_MASK;
return 0;
}
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index c12fd0b89883..b369d3e3876d 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -40,7 +40,7 @@ static int discover_region(struct device *dev, void *unused)
return 0;
cxled = to_cxl_endpoint_decoder(dev);
- if ((cxled->cxld.flags & CXL_DECODER_F_ENABLE) == 0)
+ if ((cxled->cxld.config.flags & CXL_DECODER_F_ENABLE) == 0)
return 0;
if (cxled->state != CXL_DECODER_STATE_AUTO)
@@ -56,7 +56,7 @@ static int discover_region(struct device *dev, void *unused)
rc = cxl_add_to_region(cxled);
if (rc)
dev_dbg(dev, "failed to add to region: %#llx-%#llx\n",
- cxled->cxld.hpa_range.start, cxled->cxld.hpa_range.end);
+ cxled->cxld.config.hpa_range.start, cxled->cxld.config.hpa_range.end);
return 0;
}
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 69941f7fdb76..237b31d54249 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -35,15 +35,28 @@ enum cxl_decoder_type {
#define CXL_DECODER_MAX_INTERLEAVE 16
/**
- * struct cxl_decoder - Common CXL HDM Decoder Attributes
- * @dev: this decoder's device
+ * struct cxl_decoder_config - CXL HDM decoder programming state
* @id: kernel device name id
* @hpa_range: Host physical address range mapped by this decoder
* @interleave_ways: number of cxl_dports in this decode
* @interleave_granularity: data stride per dport
* @target_type: accelerator vs expander (type2 vs type3) selector
- * @region: currently assigned region for this decoder
* @flags: memory type capabilities and locking
+ */
+struct cxl_decoder_config {
+ int id;
+ struct range hpa_range;
+ int interleave_ways;
+ int interleave_granularity;
+ enum cxl_decoder_type target_type;
+ unsigned long flags;
+};
+
+/**
+ * struct cxl_decoder - Common CXL HDM Decoder Attributes
+ * @dev: this decoder's device
+ * @config: HDM decoder programming state
+ * @region: currently assigned region for this decoder
* @target_map: cached copy of hardware port-id list, available at init
* before all @dport objects have been instantiated. While
* dport id is 8bit, CFMWS interleave targets are 32bits.
@@ -52,13 +65,8 @@ enum cxl_decoder_type {
*/
struct cxl_decoder {
struct device dev;
- int id;
- struct range hpa_range;
- int interleave_ways;
- int interleave_granularity;
- enum cxl_decoder_type target_type;
+ struct cxl_decoder_config config;
struct cxl_region *region;
- unsigned long flags;
u32 target_map[CXL_DECODER_MAX_INTERLEAVE];
int (*commit)(struct cxl_decoder *cxld);
void (*reset)(struct cxl_decoder *cxld);
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 2921f1111870..034d3a923b2c 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -773,7 +773,7 @@ static int map_targets(struct device *dev, void *data)
* id into the low bits.
*
* The key is formed as:
- * ((unsigned long)port->uport_dev << 4) | cxld->id
+ * ((unsigned long)port->uport_dev << 4) | cxld->config.id
*
* The low bits hold the decoder id (which must fit in 4 bits) while
* the remaining bits identify the upstream port. This key is only used
@@ -783,9 +783,9 @@ static unsigned long cxld_registry_index(struct cxl_decoder *cxld)
{
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
- dev_WARN_ONCE(&port->dev, cxld->id >= 16,
- "decoder id:%d out of range\n", cxld->id);
- return (((unsigned long)port->uport_dev) << 4) | cxld->id;
+ dev_WARN_ONCE(&port->dev, cxld->config.id >= 16,
+ "decoder id:%d out of range\n", cxld->config.id);
+ return (((unsigned long)port->uport_dev) << 4) | cxld->config.id;
}
struct cxl_test_decoder {
@@ -801,14 +801,15 @@ static struct cxl_test_decoder *cxld_registry_find(struct cxl_decoder *cxld)
return xa_load(&decoder_registry, cxld_registry_index(cxld));
}
-#define dbg_cxld(port, msg, cxld) \
- do { \
- struct cxl_decoder *___d = (cxld); \
- dev_dbg((port)->uport_dev, \
+#define dbg_cxld(port, msg, cxld) \
+ do { \
+ struct cxl_decoder *___d = (cxld); \
+ const struct cxl_decoder_config *___c = &___d->config; \
+ dev_dbg((port)->uport_dev, \
"decoder%d: %s range: %#llx-%#llx iw: %d ig: %d flags: %#lx\n", \
- ___d->id, msg, ___d->hpa_range.start, \
- ___d->hpa_range.end + 1, ___d->interleave_ways, \
- ___d->interleave_granularity, ___d->flags); \
+ ___c->id, msg, ___c->hpa_range.start, \
+ ___c->hpa_range.end + 1, ___c->interleave_ways, \
+ ___c->interleave_granularity, ___c->flags); \
} while (0)
static int mock_decoder_commit(struct cxl_decoder *cxld);
@@ -817,12 +818,7 @@ static void init_disabled_mock_decoder(struct cxl_decoder *cxld);
static void cxld_copy(struct cxl_decoder *a, struct cxl_decoder *b)
{
- a->id = b->id;
- a->hpa_range = b->hpa_range;
- a->interleave_ways = b->interleave_ways;
- a->interleave_granularity = b->interleave_granularity;
- a->target_type = b->target_type;
- a->flags = b->flags;
+ a->config = b->config;
a->commit = mock_decoder_commit;
a->reset = mock_decoder_reset;
}
@@ -847,7 +843,7 @@ static int cxld_registry_restore(struct cxl_decoder *cxld,
struct cxl_switch_decoder *cxlsd =
to_cxl_switch_decoder(&cxld->dev);
- if (!(td->cxlsd.cxld.flags & CXL_DECODER_F_ENABLE))
+ if (!(td->cxlsd.cxld.config.flags & CXL_DECODER_F_ENABLE))
return 0;
dbg_cxld(port, "restore", &td->cxlsd.cxld);
@@ -860,13 +856,13 @@ static int cxld_registry_restore(struct cxl_decoder *cxld,
cxld->target_map[i] = td->cxlsd.cxld.target_map[i];
}
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
} else {
struct cxl_endpoint_decoder *cxled =
to_cxl_endpoint_decoder(&cxld->dev);
- if (!(td->cxled.cxld.flags & CXL_DECODER_F_ENABLE))
+ if (!(td->cxled.cxld.config.flags & CXL_DECODER_F_ENABLE))
return 0;
dbg_cxld(port, "restore", &td->cxled.cxld);
@@ -881,7 +877,7 @@ static int cxld_registry_restore(struct cxl_decoder *cxld,
init_disabled_mock_decoder(cxld);
return rc;
}
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
}
return 0;
@@ -915,7 +911,7 @@ static void __cxld_registry_save(struct cxl_test_decoder *td,
td->cxled.state = cxled->state;
td->cxled.skip = cxled->skip;
- if (!(cxld->flags & CXL_DECODER_F_ENABLE)) {
+ if (!(cxld->config.flags & CXL_DECODER_F_ENABLE)) {
td->dpa_range.start = 0;
td->dpa_range.end = -1;
} else if (cxled->dpa_res) {
@@ -952,9 +948,9 @@ static void cxld_registry_update(struct cxl_decoder *cxld)
static int mock_decoder_commit(struct cxl_decoder *cxld)
{
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
- int id = cxld->id;
+ int id = cxld->config.id;
- if (cxld->flags & CXL_DECODER_F_ENABLE)
+ if (cxld->config.flags & CXL_DECODER_F_ENABLE)
return 0;
dev_dbg(&port->dev, "%s commit\n", dev_name(&cxld->dev));
@@ -967,7 +963,7 @@ static int mock_decoder_commit(struct cxl_decoder *cxld)
}
port->commit_end++;
- cxld->flags |= CXL_DECODER_F_ENABLE;
+ cxld->config.flags |= CXL_DECODER_F_ENABLE;
if (is_endpoint_decoder(&cxld->dev)) {
struct cxl_endpoint_decoder *cxled =
to_cxl_endpoint_decoder(&cxld->dev);
@@ -982,9 +978,9 @@ static int mock_decoder_commit(struct cxl_decoder *cxld)
static void mock_decoder_reset(struct cxl_decoder *cxld)
{
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
- int id = cxld->id;
+ int id = cxld->config.id;
- if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
+ if ((cxld->config.flags & CXL_DECODER_F_ENABLE) == 0)
return;
dev_dbg(&port->dev, "%s reset\n", dev_name(&cxld->dev));
@@ -994,7 +990,7 @@ static void mock_decoder_reset(struct cxl_decoder *cxld)
dev_dbg(&port->dev,
"%s: out of order reset, expected decoder%d.%d\n",
dev_name(&cxld->dev), port->id, port->commit_end);
- cxld->flags &= ~CXL_DECODER_F_ENABLE;
+ cxld->config.flags &= ~CXL_DECODER_F_ENABLE;
if (is_endpoint_decoder(&cxld->dev)) {
struct cxl_endpoint_decoder *cxled =
@@ -1005,7 +1001,7 @@ static void mock_decoder_reset(struct cxl_decoder *cxld)
}
if (decoder_reset_preserve_registry)
dev_dbg(port->uport_dev, "decoder%d: skip registry update\n",
- cxld->id);
+ cxld->config.id);
else
cxld_registry_update(cxld);
}
@@ -1030,12 +1026,12 @@ static struct cxl_test_decoder *cxld_registry_new(struct cxl_decoder *cxld)
static void init_disabled_mock_decoder(struct cxl_decoder *cxld)
{
- cxld->hpa_range.start = 0;
- cxld->hpa_range.end = -1;
- cxld->interleave_ways = 1;
- cxld->interleave_granularity = 0;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->flags = 0;
+ cxld->config.hpa_range.start = 0;
+ cxld->config.hpa_range.end = -1;
+ cxld->config.interleave_ways = 1;
+ cxld->config.interleave_granularity = 0;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.flags = 0;
cxld->commit = mock_decoder_commit;
cxld->reset = mock_decoder_reset;
@@ -1058,14 +1054,14 @@ static void init_disabled_mock_decoder(struct cxl_decoder *cxld)
static void default_mock_decoder(struct cxl_decoder *cxld)
{
- cxld->hpa_range = (struct range){
+ cxld->config.hpa_range = (struct range){
.start = 0,
.end = -1,
};
- cxld->interleave_ways = 1;
- cxld->interleave_granularity = 256;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.interleave_ways = 1;
+ cxld->config.interleave_granularity = 256;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
cxld->commit = mock_decoder_commit;
cxld->reset = mock_decoder_reset;
@@ -1080,7 +1076,7 @@ static int match_decoder_by_index(struct device *dev, const void *data)
if (!is_switch_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
- return cxld->id == target_id;
+ return cxld->config.id == target_id;
}
/*
@@ -1093,11 +1089,11 @@ static void size_zero_mock_decoder_ep(struct cxl_decoder *cxld, u64 base)
{
struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(&cxld->dev);
- cxld->hpa_range = DEFINE_RANGE(base, base - 1);
- cxld->interleave_ways = 2;
- cxld->interleave_granularity = 4096;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
+ cxld->config.hpa_range = DEFINE_RANGE(base, base - 1);
+ cxld->config.interleave_ways = 2;
+ cxld->config.interleave_granularity = 4096;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
cxled->state = CXL_DECODER_STATE_AUTO;
/* decoder[0] reserved [0, size/2), empty decoders sit at that watermark */
devm_cxl_dpa_reserve(cxled, mock_auto_region_size / 2, 0, 0);
@@ -1108,11 +1104,11 @@ static void size_zero_mock_decoder_ep(struct cxl_decoder *cxld, u64 base)
static void size_zero_mock_decoder_sw(struct cxl_decoder *cxld, u64 base,
int level)
{
- cxld->flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->interleave_ways = level == 0 ? 2 : 1;
- cxld->interleave_granularity = 4096;
- cxld->hpa_range = DEFINE_RANGE(base, base - 1);
+ cxld->config.flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.interleave_ways = level == 0 ? 2 : 1;
+ cxld->config.interleave_granularity = 4096;
+ cxld->config.hpa_range = DEFINE_RANGE(base, base - 1);
cxld->commit = mock_decoder_commit;
cxld->reset = mock_decoder_reset;
}
@@ -1147,7 +1143,7 @@ static enum cxld_init_type get_decoder_init_type(struct cxl_decoder *cxld,
* See 'cxl list -BMPu -m cxl_mem.0,cxl_mem.4'
*/
if (!is_endpoint_decoder(&cxld->dev) || !hb0 || pdev->id % 4 ||
- pdev->id > 4 || cxld->id > (mock_zero_size_decoders ? 2 : 0))
+ pdev->id > 4 || cxld->config.id > (mock_zero_size_decoders ? 2 : 0))
return MOCK_DECODER_INIT_DEFAULT;
return type2_test ? MOCK_DECODER_INIT_TYPE2_AUTO :
@@ -1159,9 +1155,9 @@ static bool mock_decoder_handle_saved(struct cxl_decoder *cxld, struct cxl_test_
bool enabled;
if (is_switch_decoder(&cxld->dev))
- enabled = td->cxlsd.cxld.flags & CXL_DECODER_F_ENABLE;
+ enabled = td->cxlsd.cxld.config.flags & CXL_DECODER_F_ENABLE;
else
- enabled = td->cxled.cxld.flags & CXL_DECODER_F_ENABLE;
+ enabled = td->cxled.cxld.config.flags & CXL_DECODER_F_ENABLE;
if (enabled)
return !cxld_registry_restore(cxld, td);
@@ -1183,19 +1179,19 @@ static void mock_init_hdm_type2_cxled(struct cxl_endpoint_decoder *cxled,
int id = 0;
base = window->base_hpa;
- cxld->hpa_range = (struct range) {
+ cxld->config.hpa_range = (struct range) {
.start = base,
.end = base + mock_auto_region_size - 1,
};
- cxld->interleave_ways = 1;
- eig_to_granularity(window->granularity, &cxld->interleave_granularity);
- cxld->target_type = CXL_DECODER_DEVMEM;
- cxld->flags = CXL_DECODER_F_ENABLE;
+ cxld->config.interleave_ways = 1;
+ eig_to_granularity(window->granularity, &cxld->config.interleave_granularity);
+ cxld->config.target_type = CXL_DECODER_DEVMEM;
+ cxld->config.flags = CXL_DECODER_F_ENABLE;
cxled->state = CXL_DECODER_STATE_AUTO;
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
devm_cxl_dpa_reserve(cxled, 0,
- mock_auto_region_size / cxld->interleave_ways, 0);
+ mock_auto_region_size / cxld->config.interleave_ways, 0);
cxld->commit = mock_decoder_commit;
cxld->reset = mock_decoder_reset;
@@ -1216,13 +1212,13 @@ static void mock_init_hdm_type2_cxled(struct cxl_endpoint_decoder *cxled,
cxlsd = to_cxl_switch_decoder(dev);
cxld = &cxlsd->cxld;
- cxld->target_type = CXL_DECODER_DEVMEM;
- cxld->flags = CXL_DECODER_F_ENABLE;
+ cxld->config.target_type = CXL_DECODER_DEVMEM;
+ cxld->config.flags = CXL_DECODER_F_ENABLE;
root_port->commit_end = 0;
- cxld->interleave_ways = 1;
- cxld->interleave_granularity = 4096;
+ cxld->config.interleave_ways = 1;
+ cxld->config.interleave_granularity = 4096;
cxld->target_map[0] = dport->port_id;
- cxld->hpa_range = (struct range) {
+ cxld->config.hpa_range = (struct range) {
.start = base,
.end = base + mock_auto_region_size - 1,
};
@@ -1258,7 +1254,7 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled,
int i;
/* Simulate missing cxl_mem.4 configuration */
- if (hb0 && pdev->id == 4 && cxld->id == 0 && fail_autoassemble) {
+ if (hb0 && pdev->id == 4 && cxld->config.id == 0 && fail_autoassemble) {
default_mock_decoder(cxld);
return;
}
@@ -1274,25 +1270,25 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled,
* points at a zero-size decoder, exercising the zero-size
* reservation and poison-by-endpoint code paths.
*/
- if (cxld->id == 1 || cxld->id == 2) {
+ if (cxld->config.id == 1 || cxld->config.id == 2) {
size_zero_mock_decoder_ep(cxld, base);
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
WARN_ON_ONCE(!cxld_registry_new(cxld));
return;
}
- cxld->hpa_range = (struct range) {
+ cxld->config.hpa_range = (struct range) {
.start = base,
.end = base + mock_auto_region_size - 1,
};
- cxld->interleave_ways = 2;
- eig_to_granularity(window->granularity, &cxld->interleave_granularity);
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->flags = CXL_DECODER_F_ENABLE;
+ cxld->config.interleave_ways = 2;
+ eig_to_granularity(window->granularity, &cxld->config.interleave_granularity);
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.flags = CXL_DECODER_F_ENABLE;
cxled->state = CXL_DECODER_STATE_AUTO;
- port->commit_end = cxld->id;
+ port->commit_end = cxld->config.id;
devm_cxl_dpa_reserve(cxled, 0,
- mock_auto_region_size / cxld->interleave_ways, 0);
+ mock_auto_region_size / cxld->config.interleave_ways, 0);
cxld->commit = mock_decoder_commit;
cxld->reset = mock_decoder_reset;
@@ -1326,19 +1322,19 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled,
cxlsd->cxld.target_map[0] = dport->port_id;
}
cxld = &cxlsd->cxld;
- cxld->target_type = CXL_DECODER_HOSTONLYMEM;
- cxld->flags = CXL_DECODER_F_ENABLE;
+ cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
+ cxld->config.flags = CXL_DECODER_F_ENABLE;
iter->commit_end = 0;
/*
* Switch targets 2 endpoints, while host bridge targets
* one root port
*/
if (i == 0)
- cxld->interleave_ways = 2;
+ cxld->config.interleave_ways = 2;
else
- cxld->interleave_ways = 1;
- cxld->interleave_granularity = 4096;
- cxld->hpa_range = (struct range) {
+ cxld->config.interleave_ways = 1;
+ cxld->config.interleave_granularity = 4096;
+ cxld->config.hpa_range = (struct range) {
.start = base,
.end = base + mock_auto_region_size - 1,
};
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 05/16] cxl: Introduce reusable HDM decoder settings
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (3 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 04/16] cxl: Embed decoder configuration in a standalone structure Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 06/16] cxl: Move HDM decoder helpers to built-in resource code Srirangan Madhavan
` (10 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Represent HDM programming state with struct cxl_decoder_settings and pass
it to the commit helpers. Keep endpoint skip and switch targets with their
owning types and flatten them only into transient programming settings.
Place flags with the programming state and leave runtime region ownership
outside the snapshot.
Separate commit initiation from completion waiting so reset restoration
can reuse register programming without changing normal DPA-lock policy.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/core.h | 3 ++
drivers/cxl/core/hdm.c | 82 ++++++++++++++++++++++++++---------------
include/cxl/cxl.h | 10 +++++
3 files changed, 66 insertions(+), 29 deletions(-)
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 983d7690c3a5..a3fddb2bed63 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -139,6 +139,9 @@ struct cxl_rwsem {
extern struct cxl_rwsem cxl_rwsem;
+void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings);
+int cxld_await_commit(void __iomem *hdm, int id);
+
int cxl_memdev_init(void);
void cxl_memdev_exit(void);
void cxl_mbox_init(void);
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 9e05032a5426..d3f21dfda146 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -707,7 +707,7 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, u64 size)
return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
}
-static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
+static void cxld_set_interleave(struct cxl_decoder_config *config, u32 *ctrl)
{
u16 eig;
u8 eiw;
@@ -716,12 +716,12 @@ static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
* Input validation ensures these warns never fire, but otherwise
* suppress unititalized variable usage warnings.
*/
- if (WARN_ONCE(ways_to_eiw(cxld->config.interleave_ways, &eiw),
- "invalid interleave_ways: %d\n", cxld->config.interleave_ways))
+ if (WARN_ONCE(ways_to_eiw(config->interleave_ways, &eiw),
+ "invalid interleave_ways: %d\n", config->interleave_ways))
return;
- if (WARN_ONCE(granularity_to_eig(cxld->config.interleave_granularity, &eig),
+ if (WARN_ONCE(granularity_to_eig(config->interleave_granularity, &eig),
"invalid interleave_granularity: %d\n",
- cxld->config.interleave_granularity))
+ config->interleave_granularity))
return;
u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
@@ -729,10 +729,10 @@ static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
*ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
}
-static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
+static void cxld_set_type(struct cxl_decoder_config *config, u32 *ctrl)
{
u32p_replace_bits(ctrl,
- !!(cxld->config.target_type == CXL_DECODER_HOSTONLYMEM),
+ !!(config->target_type == CXL_DECODER_HOSTONLYMEM),
CXL_HDM_DECODER0_CTRL_HOSTONLY);
}
@@ -764,7 +764,7 @@ static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
* clock skew and other marginal behavior
*/
#define COMMIT_TIMEOUT_MS 20
-static int cxld_await_commit(void __iomem *hdm, int id)
+int cxld_await_commit(void __iomem *hdm, int id)
{
u32 ctrl;
int i;
@@ -784,45 +784,66 @@ static int cxld_await_commit(void __iomem *hdm, int id)
return -ETIMEDOUT;
}
-static void setup_hw_decoder(struct cxl_decoder *cxld, void __iomem *hdm)
+static void setup_hw_decoder(void __iomem *hdm,
+ struct cxl_decoder_settings *settings)
{
- int id = cxld->config.id;
+ struct cxl_decoder_config *config = &settings->config;
+ int id = config->id;
+ u64 target_or_skip_reg_val;
u64 base, size;
u32 ctrl;
- /* common decoder settings */
- ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->config.id));
- cxld_set_interleave(cxld, &ctrl);
- cxld_set_type(cxld, &ctrl);
- base = cxld->config.hpa_range.start;
- size = range_len(&cxld->config.hpa_range);
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ cxld_set_interleave(config, &ctrl);
+ cxld_set_type(config, &ctrl);
+ base = config->hpa_range.start;
+ size = range_len(&config->hpa_range);
+ target_or_skip_reg_val = settings->target_or_skip_reg_val;
writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
+ /* Target-list and endpoint-skip registers alias the same slot. */
+ writel(upper_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_HIGH(id));
+ writel(lower_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_LOW(id));
+
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+}
+
+void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings)
+{
+ lockdep_assert_held(&cxl_rwsem.dpa);
+ setup_hw_decoder(hdm, settings);
+}
+
+/*
+ * Endpoint skip and switch targets have different owners. Keep that state with
+ * its owning type and flatten it only into a transient register-programming
+ * snapshot.
+ */
+static void cxl_decoder_snapshot(struct cxl_decoder *cxld,
+ struct cxl_decoder_settings *settings)
+{
+ lockdep_assert_held(&cxl_rwsem.dpa);
+
+ *settings = (struct cxl_decoder_settings) {
+ .config = cxld->config,
+ };
if (is_switch_decoder(&cxld->dev)) {
struct cxl_switch_decoder *cxlsd =
to_cxl_switch_decoder(&cxld->dev);
- void __iomem *tl_hi = hdm + CXL_HDM_DECODER0_TL_HIGH(id);
- void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id);
u64 targets;
cxlsd_set_targets(cxlsd, &targets);
- writel(upper_32_bits(targets), tl_hi);
- writel(lower_32_bits(targets), tl_lo);
+ settings->target_or_skip_reg_val = targets;
} else {
struct cxl_endpoint_decoder *cxled =
to_cxl_endpoint_decoder(&cxld->dev);
- void __iomem *sk_hi = hdm + CXL_HDM_DECODER0_SKIP_HIGH(id);
- void __iomem *sk_lo = hdm + CXL_HDM_DECODER0_SKIP_LOW(id);
- writel(upper_32_bits(cxled->skip), sk_hi);
- writel(lower_32_bits(cxled->skip), sk_lo);
+ settings->target_or_skip_reg_val = cxled->skip;
}
-
- writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
}
static int cxl_decoder_commit(struct cxl_decoder *cxld)
@@ -830,6 +851,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+ struct cxl_decoder_settings settings;
int id = cxld->config.id, rc;
if (cxld->config.flags & CXL_DECODER_F_ENABLE)
@@ -862,10 +884,12 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
}
}
- scoped_guard(rwsem_read, &cxl_rwsem.dpa)
- setup_hw_decoder(cxld, hdm);
+ scoped_guard(rwsem_read, &cxl_rwsem.dpa) {
+ cxl_decoder_snapshot(cxld, &settings);
+ cxl_commit_start(hdm, &settings);
+ }
- rc = cxld_await_commit(hdm, cxld->config.id);
+ rc = cxld_await_commit(hdm, settings.config.id);
if (rc) {
dev_dbg(&port->dev, "%s: error %d committing decoder\n",
dev_name(&cxld->dev), rc);
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 237b31d54249..67c81be47fbb 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -72,6 +72,16 @@ struct cxl_decoder {
void (*reset)(struct cxl_decoder *cxld);
};
+/**
+ * struct cxl_decoder_settings - CXL HDM decoder programming snapshot
+ * @config: common decoder configuration
+ * @target_or_skip_reg_val: switch target list or endpoint skip register value
+ */
+struct cxl_decoder_settings {
+ struct cxl_decoder_config config;
+ u64 target_or_skip_reg_val;
+};
+
/*
* Using struct_group() allows for per register-block-type helper routines,
* without requiring block-type agnostic code to include the prefix.
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 06/16] cxl: Move HDM decoder helpers to built-in resource code
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (4 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 05/16] cxl: Introduce reusable HDM decoder settings Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 07/16] cxl: Share HDM decoder register unpacking Srirangan Madhavan
` (9 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Move the refactored HDM programming helpers and cxl_rwsem from hdm.c to
resource.c. Build resource.o under CONFIG_CXL_RESET so the helpers are
available to built-in PCI code when CXL_BUS is modular. Export only the
symbols used by cxl_core.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/Kconfig | 4 ++
drivers/cxl/core/Makefile | 1 +
drivers/cxl/core/hdm.c | 93 -------------------------------
drivers/cxl/core/resource.c | 106 ++++++++++++++++++++++++++++++++++++
4 files changed, 111 insertions(+), 93 deletions(-)
create mode 100644 drivers/cxl/core/resource.c
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index 80aeb0d556bd..0cd704670735 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -6,6 +6,7 @@ menuconfig CXL_BUS
select FW_UPLOAD
select PCI_DOE
select FIRMWARE_TABLE
+ select CXL_RESET
select NUMA_KEEP_MEMINFO if NUMA_MEMBLKS
select FWCTL if CXL_FEATURES
help
@@ -244,3 +245,6 @@ config CXL_ATL
depends on ACPI_PRMT && AMD_NB
endif
+
+config CXL_RESET
+ bool
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index ce7213818d3c..30470799e059 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CXL_BUS) += cxl_core.o
+obj-$(CONFIG_CXL_RESET) += resource.o
obj-$(CONFIG_CXL_SUSPEND) += suspend.o
ccflags-y += -I$(srctree)/drivers/cxl
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index d3f21dfda146..629e3420ad0b 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -16,11 +16,6 @@
* for enumerating these registers and capabilities.
*/
-struct cxl_rwsem cxl_rwsem = {
- .region = __RWSEM_INITIALIZER(cxl_rwsem.region),
- .dpa = __RWSEM_INITIALIZER(cxl_rwsem.dpa),
-};
-
static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld)
{
int rc;
@@ -707,35 +702,6 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, u64 size)
return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
}
-static void cxld_set_interleave(struct cxl_decoder_config *config, u32 *ctrl)
-{
- u16 eig;
- u8 eiw;
-
- /*
- * Input validation ensures these warns never fire, but otherwise
- * suppress unititalized variable usage warnings.
- */
- if (WARN_ONCE(ways_to_eiw(config->interleave_ways, &eiw),
- "invalid interleave_ways: %d\n", config->interleave_ways))
- return;
- if (WARN_ONCE(granularity_to_eig(config->interleave_granularity, &eig),
- "invalid interleave_granularity: %d\n",
- config->interleave_granularity))
- return;
-
- u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
- u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK);
- *ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
-}
-
-static void cxld_set_type(struct cxl_decoder_config *config, u32 *ctrl)
-{
- u32p_replace_bits(ctrl,
- !!(config->target_type == CXL_DECODER_HOSTONLYMEM),
- CXL_HDM_DECODER0_CTRL_HOSTONLY);
-}
-
static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
{
struct cxl_dport **t = &cxlsd->target[0];
@@ -758,65 +724,6 @@ static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
*tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id);
}
-/*
- * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set
- * committed or error within 10ms, but just be generous with 20ms to account for
- * clock skew and other marginal behavior
- */
-#define COMMIT_TIMEOUT_MS 20
-int cxld_await_commit(void __iomem *hdm, int id)
-{
- u32 ctrl;
- int i;
-
- for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
- ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
- if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
- ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
- writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
- return -EIO;
- }
- if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
- return 0;
- fsleep(1000);
- }
-
- return -ETIMEDOUT;
-}
-
-static void setup_hw_decoder(void __iomem *hdm,
- struct cxl_decoder_settings *settings)
-{
- struct cxl_decoder_config *config = &settings->config;
- int id = config->id;
- u64 target_or_skip_reg_val;
- u64 base, size;
- u32 ctrl;
-
- ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
- cxld_set_interleave(config, &ctrl);
- cxld_set_type(config, &ctrl);
- base = config->hpa_range.start;
- size = range_len(&config->hpa_range);
- target_or_skip_reg_val = settings->target_or_skip_reg_val;
-
- writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
- writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
- writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
- writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
- /* Target-list and endpoint-skip registers alias the same slot. */
- writel(upper_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_HIGH(id));
- writel(lower_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_LOW(id));
-
- writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
-}
-
-void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings)
-{
- lockdep_assert_held(&cxl_rwsem.dpa);
- setup_hw_decoder(hdm, settings);
-}
-
/*
* Endpoint skip and switch targets have different owners. Keep that state with
* its owning type and flatten it only into a transient register-programming
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
new file mode 100644
index 000000000000..ff027cb89e57
--- /dev/null
+++ b/drivers/cxl/core/resource.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2026 NVIDIA Corporation & Affiliates */
+#include <linux/delay.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+#include "cxl.h"
+#include "core.h"
+
+struct cxl_rwsem cxl_rwsem = {
+ .region = __RWSEM_INITIALIZER(cxl_rwsem.region),
+ .dpa = __RWSEM_INITIALIZER(cxl_rwsem.dpa),
+};
+EXPORT_SYMBOL_FOR_MODULES(cxl_rwsem, "cxl_core");
+
+static void cxld_set_interleave(struct cxl_decoder_config *config, u32 *ctrl)
+{
+ u16 eig;
+ u8 eiw;
+
+ /*
+ * Input validation ensures these warns never fire, but otherwise
+ * suppress unititalized variable usage warnings.
+ */
+ if (WARN_ONCE(ways_to_eiw(config->interleave_ways, &eiw),
+ "invalid interleave_ways: %d\n", config->interleave_ways))
+ return;
+ if (WARN_ONCE(granularity_to_eig(config->interleave_granularity, &eig),
+ "invalid interleave_granularity: %d\n",
+ config->interleave_granularity))
+ return;
+
+ u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
+ u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK);
+ *ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
+}
+
+static void cxld_set_type(struct cxl_decoder_config *config, u32 *ctrl)
+{
+ u32p_replace_bits(ctrl,
+ !!(config->target_type == CXL_DECODER_HOSTONLYMEM),
+ CXL_HDM_DECODER0_CTRL_HOSTONLY);
+}
+
+/*
+ * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set
+ * committed or error within 10ms, but just be generous with 20ms to account for
+ * clock skew and other marginal behavior
+ */
+#define COMMIT_TIMEOUT_MS 20
+int cxld_await_commit(void __iomem *hdm, int id)
+{
+ u32 ctrl;
+ int i;
+
+ for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
+ ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ return -EIO;
+ }
+ if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
+ return 0;
+ fsleep(1000);
+ }
+
+ return -ETIMEDOUT;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxld_await_commit, "cxl_core");
+
+static void setup_hw_decoder(void __iomem *hdm,
+ struct cxl_decoder_settings *settings)
+{
+ struct cxl_decoder_config *config = &settings->config;
+ int id = config->id;
+ u64 target_or_skip_reg_val;
+ u64 base, size;
+ u32 ctrl;
+
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ cxld_set_interleave(config, &ctrl);
+ cxld_set_type(config, &ctrl);
+ base = config->hpa_range.start;
+ size = range_len(&config->hpa_range);
+ target_or_skip_reg_val = settings->target_or_skip_reg_val;
+
+ writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
+ writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
+ writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
+ writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
+ /* Target-list and endpoint-skip registers alias the same slot. */
+ writel(upper_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_HIGH(id));
+ writel(lower_32_bits(target_or_skip_reg_val), hdm + CXL_HDM_DECODER0_TL_LOW(id));
+
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+}
+
+void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings)
+{
+ lockdep_assert_held(&cxl_rwsem.dpa);
+ setup_hw_decoder(hdm, settings);
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_commit_start, "cxl_core");
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 07/16] cxl: Share HDM decoder register unpacking
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (5 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 06/16] cxl: Move HDM decoder helpers to built-in resource code Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 08/16] cxl: Reject overflowing HDM decoder ranges Srirangan Madhavan
` (8 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Factor HDM register parsing into cxl_hdm_unpack_decoder(). Validate the
range and interleave parameters in locals before publishing the complete
settings, including enable/lock flags and the target-or-skip register
value.
Use the unpacked settings in init_hdm_decoder(), retaining the target-list
union and passing endpoint skip state to the existing DPA reservation
helper.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/core.h | 4 +++
drivers/cxl/core/hdm.c | 68 +++++++++++--------------------------
drivers/cxl/core/resource.c | 57 +++++++++++++++++++++++++++++++
3 files changed, 81 insertions(+), 48 deletions(-)
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index a3fddb2bed63..a0bef246121d 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -142,6 +142,10 @@ extern struct cxl_rwsem cxl_rwsem;
void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings);
int cxld_await_commit(void __iomem *hdm, int id);
+int cxl_hdm_unpack_decoder(struct cxl_decoder_settings *settings, int id,
+ u32 ctrl, u64 base, u64 size,
+ u64 target_or_skip_reg_val);
+
int cxl_memdev_init(void);
void cxl_memdev_exit(void);
void cxl_mbox_init(void);
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 629e3420ad0b..b6a8fe83d336 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -932,8 +932,8 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
u64 *dpa_base, struct cxl_endpoint_dvsec_info *info)
{
struct cxl_endpoint_decoder *cxled = NULL;
- u64 size, base, skip, dpa_size, lo, hi;
- bool committed;
+ struct cxl_decoder_settings settings;
+ u64 size, base, skip, dpa_size, lo, hi, target_or_skip_reg_val;
u32 remainder;
int i, rc;
u32 ctrl;
@@ -953,35 +953,28 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
lo = readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which));
hi = readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(which));
size = (hi << 32) + lo;
- committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED);
+ lo = readl(hdm + CXL_HDM_DECODER0_TL_LOW(which));
+ hi = readl(hdm + CXL_HDM_DECODER0_TL_HIGH(which));
+ target_or_skip_reg_val = (hi << 32) + lo;
+ rc = cxl_hdm_unpack_decoder(&settings, which, ctrl, base, size,
+ target_or_skip_reg_val);
+ if (rc) {
+ dev_warn(&port->dev,
+ "decoder%d.%d: Invalid decoder configuration (ctrl: %#x): %d\n",
+ port->id, cxld->config.id, ctrl, rc);
+ return rc;
+ }
+
cxld->commit = cxl_decoder_commit;
cxld->reset = cxl_decoder_reset;
-
- if (!committed)
- size = 0;
- if (base == U64_MAX || size == U64_MAX) {
- dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",
- port->id, cxld->config.id);
- return -ENXIO;
- }
+ cxld->config = settings.config;
+ size = range_len(&cxld->config.hpa_range);
if (info)
cxled = to_cxl_endpoint_decoder(&cxld->dev);
- cxld->config.hpa_range = (struct range) {
- .start = base,
- .end = base + size - 1,
- };
/* decoders are enabled if committed */
- if (committed) {
- cxld->config.flags |= CXL_DECODER_F_ENABLE;
- if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
- cxld->config.flags |= CXL_DECODER_F_LOCK;
- if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
- cxld->config.target_type = CXL_DECODER_HOSTONLYMEM;
- else
- cxld->config.target_type = CXL_DECODER_DEVMEM;
-
+ if (cxld->config.flags & CXL_DECODER_F_ENABLE) {
guard(rwsem_write)(&cxl_rwsem.region);
if (cxld->config.id != cxl_num_decoders_committed(port)) {
dev_warn(&port->dev,
@@ -1015,38 +1008,19 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
}
}
- rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
- &cxld->config.interleave_ways);
- if (rc) {
- dev_warn(&port->dev,
- "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",
- port->id, cxld->config.id, ctrl);
- return rc;
- }
- rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
- &cxld->config.interleave_granularity);
- if (rc) {
- dev_warn(&port->dev,
- "decoder%d.%d: Invalid interleave granularity (ctrl: %#x)\n",
- port->id, cxld->config.id, ctrl);
- return rc;
- }
-
dev_dbg(&port->dev, "decoder%d.%d: range: %#llx-%#llx iw: %d ig: %d\n",
port->id, cxld->config.id, cxld->config.hpa_range.start, cxld->config.hpa_range.end,
cxld->config.interleave_ways, cxld->config.interleave_granularity);
if (!cxled) {
- lo = readl(hdm + CXL_HDM_DECODER0_TL_LOW(which));
- hi = readl(hdm + CXL_HDM_DECODER0_TL_HIGH(which));
- target_list.value = (hi << 32) + lo;
+ target_list.value = settings.target_or_skip_reg_val;
for (i = 0; i < cxld->config.interleave_ways; i++)
cxld->target_map[i] = target_list.target_id[i];
return 0;
}
- if (!committed)
+ if (!(cxld->config.flags & CXL_DECODER_F_ENABLE))
return 0;
dpa_size = div_u64_rem(size, cxld->config.interleave_ways, &remainder);
@@ -1056,9 +1030,7 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
port->id, cxld->config.id, size, cxld->config.interleave_ways);
return -ENXIO;
}
- lo = readl(hdm + CXL_HDM_DECODER0_SKIP_LOW(which));
- hi = readl(hdm + CXL_HDM_DECODER0_SKIP_HIGH(which));
- skip = (hi << 32) + lo;
+ skip = settings.target_or_skip_reg_val;
rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip);
if (rc) {
dev_err(&port->dev,
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index ff027cb89e57..8dfeb12de8c9 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -104,3 +104,60 @@ void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings)
setup_hw_decoder(hdm, settings);
}
EXPORT_SYMBOL_FOR_MODULES(cxl_commit_start, "cxl_core");
+
+int cxl_hdm_unpack_decoder(struct cxl_decoder_settings *settings, int id,
+ u32 ctrl, u64 base, u64 size,
+ u64 target_or_skip_reg_val)
+{
+ bool committed = FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl);
+ enum cxl_decoder_type target_type = 0;
+ int interleave_granularity;
+ int interleave_ways;
+ unsigned long flags = 0;
+ struct range hpa_range;
+ int rc;
+
+ if (!committed)
+ size = 0;
+ if (base == U64_MAX || size == U64_MAX)
+ return -ENXIO;
+
+ hpa_range = (struct range) {
+ .start = base,
+ .end = base + size - 1,
+ };
+
+ if (committed) {
+ flags |= CXL_DECODER_F_ENABLE;
+ if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
+ flags |= CXL_DECODER_F_LOCK;
+ if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
+ target_type = CXL_DECODER_HOSTONLYMEM;
+ else
+ target_type = CXL_DECODER_DEVMEM;
+ }
+
+ rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
+ &interleave_ways);
+ if (rc)
+ return rc;
+ rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
+ &interleave_granularity);
+ if (rc)
+ return rc;
+
+ *settings = (struct cxl_decoder_settings) {
+ .config = {
+ .id = id,
+ .hpa_range = hpa_range,
+ .interleave_ways = interleave_ways,
+ .interleave_granularity = interleave_granularity,
+ .target_type = target_type,
+ .flags = flags,
+ },
+ .target_or_skip_reg_val = target_or_skip_reg_val,
+ };
+
+ return 0;
+}
+EXPORT_SYMBOL_FOR_MODULES(cxl_hdm_unpack_decoder, "cxl_core");
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 08/16] cxl: Reject overflowing HDM decoder ranges
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (6 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 07/16] cxl: Share HDM decoder register unpacking Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 09/16] cxl: Refresh cached PCI HDM decoder settings Srirangan Madhavan
` (7 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
An HDM decoder with a nonzero size can report a base and size whose end
address wraps the 64-bit address space. Reject that programming before
publishing the decoder range, so enumeration and later reset handling
cannot use the wrapped range.
Use check_add_overflow() for nonzero ranges. Preserve the existing
empty-range representation for zero-size decoders.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 8dfeb12de8c9..8d2fbc49a06f 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -115,16 +115,21 @@ int cxl_hdm_unpack_decoder(struct cxl_decoder_settings *settings, int id,
int interleave_ways;
unsigned long flags = 0;
struct range hpa_range;
+ u64 end;
int rc;
if (!committed)
size = 0;
if (base == U64_MAX || size == U64_MAX)
return -ENXIO;
+ if (size && check_add_overflow(base, size - 1, &end))
+ return -ENXIO;
+ if (!size)
+ end = base - 1;
hpa_range = (struct range) {
.start = base,
- .end = base + size - 1,
+ .end = end,
};
if (committed) {
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 09/16] cxl: Refresh cached PCI HDM decoder settings
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (7 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 08/16] cxl: Reject overflowing HDM decoder ranges Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 10/16] cxl: Cache endpoint HDM state during PCI enumeration Srirangan Madhavan
` (6 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Early PCI discovery creates the HDM cache, while later CXL enumeration and
decoder operations provide updated programming state.
Refresh the PCI snapshot when decoders are enumerated, committed, or reset
so reset recovery need not walk the CXL topology. Ignore updates when no
cache exists and reject decoder-count mismatches.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/hdm.c | 58 ++++++++++++++++++++++++++++++++++++++++++
include/cxl/cxl.h | 22 ++++++++++++++++
include/linux/pci.h | 6 +++++
3 files changed, 86 insertions(+)
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index b6a8fe83d336..d6b3afbffa3e 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -753,6 +753,44 @@ static void cxl_decoder_snapshot(struct cxl_decoder *cxld,
}
}
+static void cxl_hdm_refresh_decoder(struct cxl_hdm *cxlhdm,
+ struct cxl_decoder *cxld)
+{
+ struct cxl_port *port = cxlhdm->port;
+ void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+ struct cxl_decoder_settings *settings;
+ struct cxl_hdm_info *info;
+ struct pci_dev *pdev __free(pci_dev_put) =
+ cxl_port_get_uport_pci_dev(port);
+
+ if (!pdev || !hdm)
+ return;
+
+ guard(rwsem_write)(&cxl_rwsem.dpa);
+ info = pdev->hdm;
+ if (!info)
+ return;
+ if (cxld->config.id < 0 || cxld->config.id >= info->decoder_count) {
+ pci_warn(pdev, "CXL HDM decoder %d exceeds cached count %d\n",
+ cxld->config.id, info->decoder_count);
+ return;
+ }
+
+ info->global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+ settings = &info->settings[cxld->config.id];
+
+ /*
+ * A disabled decoder's software object may retain its old range and
+ * target state. Leave only the decoder id in the cached settings so stale
+ * state is not restored as an enabled decode.
+ */
+ *settings = (struct cxl_decoder_settings) {
+ .config.id = cxld->config.id,
+ };
+ if (cxld->config.flags & CXL_DECODER_F_ENABLE)
+ cxl_decoder_snapshot(cxld, settings);
+}
+
static int cxl_decoder_commit(struct cxl_decoder *cxld)
{
struct cxl_port *port = to_cxl_port(cxld->dev.parent);
@@ -804,6 +842,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
}
port->commit_end++;
cxld->config.flags |= CXL_DECODER_F_ENABLE;
+ cxl_hdm_refresh_decoder(cxlhdm, cxld);
return 0;
}
@@ -876,6 +915,7 @@ static void cxl_decoder_reset(struct cxl_decoder *cxld)
writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
cxld->config.flags &= ~CXL_DECODER_F_ENABLE;
+ cxl_hdm_refresh_decoder(cxlhdm, cxld);
/* Userspace is now responsible for reconfiguring this decoder */
if (is_endpoint_decoder(&cxld->dev)) {
@@ -1086,6 +1126,23 @@ static int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
int i;
u64 dpa_base = 0;
+ if (is_cxl_endpoint(port) && hdm) {
+ struct pci_dev *pdev __free(pci_dev_put) =
+ cxl_port_get_uport_pci_dev(port);
+
+ if (pdev) {
+ guard(rwsem_read)(&cxl_rwsem.dpa);
+
+ if (pdev->hdm &&
+ pdev->hdm->decoder_count != cxlhdm->decoder_count) {
+ pci_warn(pdev,
+ "CXL HDM cache decoder count mismatch: cached=%d hdm=%d\n",
+ pdev->hdm->decoder_count, cxlhdm->decoder_count);
+ return -ENXIO;
+ }
+ }
+ }
+
cxl_settle_decoders(cxlhdm);
for (i = 0; i < cxlhdm->decoder_count; i++) {
@@ -1124,6 +1181,7 @@ static int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
put_device(&cxld->dev);
return rc;
}
+ cxl_hdm_refresh_decoder(cxlhdm, cxld);
rc = add_hdm_decoder(port, cxld);
if (rc) {
dev_warn(&port->dev,
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 67c81be47fbb..e200c5c56b92 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -82,6 +82,28 @@ struct cxl_decoder_settings {
u64 target_or_skip_reg_val;
};
+/**
+ * struct cxl_hdm_info - cached CXL HDM state for a PCI device
+ * @decoder_count: number of entries in @settings
+ * @hdm_bar: PCI BAR containing the HDM decoder capability
+ * @hdm_offset: offset of the HDM decoder capability in @hdm_bar
+ * @hdm_size: size of the HDM decoder register block
+ * @global_ctrl: HDM decoder global control register
+ * @dvsec_ctrl: CXL DVSEC control register
+ * @dvsec_ctrl_valid: whether @dvsec_ctrl contains valid state
+ * @settings: per-decoder programming state
+ */
+struct cxl_hdm_info {
+ int decoder_count;
+ int hdm_bar;
+ resource_size_t hdm_offset;
+ resource_size_t hdm_size;
+ u32 global_ctrl;
+ u16 dvsec_ctrl;
+ bool dvsec_ctrl_valid;
+ struct cxl_decoder_settings settings[] __counted_by(decoder_count);
+};
+
/*
* Using struct_group() allows for per register-block-type helper routines,
* without requiring block-type agnostic code to include the prefix.
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d31a8d107b1e..7bb37fcb556d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -339,6 +339,9 @@ struct pcie_link_state;
struct pci_sriov;
struct pci_p2pdma;
struct rcec_ea;
+#ifdef CONFIG_CXL_RESET
+struct cxl_hdm_info;
+#endif
/* struct pci_dev - describes a PCI device
*
@@ -566,6 +569,9 @@ struct pci_dev {
#ifdef CONFIG_PCI_DOE
struct xarray doe_mbs; /* Data Object Exchange mailboxes */
#endif
+#ifdef CONFIG_CXL_RESET
+ struct cxl_hdm_info *hdm; /* CXL HDM decoder state */
+#endif
#ifdef CONFIG_PCI_NPEM
struct npem *npem; /* Native PCIe Enclosure Management */
#endif
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 10/16] cxl: Cache endpoint HDM state during PCI enumeration
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (8 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 09/16] cxl: Refresh cached PCI HDM decoder settings Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 11/16] cxl: Add CXL Device Reset sequencing Srirangan Madhavan
` (5 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
PCI capability initialization runs before BAR resources are finalized,
while driver binding is too late for driver-independent reset support.
Create pci_dev->hdm during pci_bus_add_device(), after PCI resource setup
and before driver binding.
Cache BAR-relative HDM location, global control, decoder settings, and CXL
Device DVSEC Control, then publish the completed cache under cxl_rwsem.dpa.
Restore PCI_COMMAND after temporary MMIO access and reject decoder-count
changes.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/Makefile | 3 +-
drivers/cxl/core/pci.c | 15 +-
drivers/cxl/core/regs.c | 9 ++
drivers/cxl/core/resource.c | 277 ++++++++++++++++++++++++++++++++++++
drivers/pci/bus.c | 2 +
drivers/pci/probe.c | 2 +
include/cxl/cxl.h | 21 +++
tools/testing/cxl/Kbuild | 1 -
8 files changed, 326 insertions(+), 4 deletions(-)
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index 30470799e059..2335059f687a 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CXL_BUS) += cxl_core.o
-obj-$(CONFIG_CXL_RESET) += resource.o
+obj-$(CONFIG_CXL_RESET) += regs.o resource.o
obj-$(CONFIG_CXL_SUSPEND) += suspend.o
ccflags-y += -I$(srctree)/drivers/cxl
@@ -8,7 +8,6 @@ CFLAGS_trace.o = -DTRACE_INCLUDE_PATH=. -I$(src)
cxl_core-y := port.o
cxl_core-y += pmem.o
-cxl_core-y += regs.o
cxl_core-y += memdev.o
cxl_core-y += mbox.o
cxl_core-y += pci.o
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9411694b93b3..5fef673ecd65 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -180,6 +180,16 @@ int cxl_await_media_ready(struct cxl_dev_state *cxlds)
}
EXPORT_SYMBOL_NS_GPL(cxl_await_media_ready, "CXL");
+static void cxl_hdm_cache_dvsec_ctrl(struct pci_dev *pdev, u16 ctrl)
+{
+ guard(rwsem_write)(&cxl_rwsem.dpa);
+ if (!pdev->hdm)
+ return;
+
+ pdev->hdm->dvsec_ctrl = ctrl;
+ pdev->hdm->dvsec_ctrl_valid = true;
+}
+
static int cxl_set_mem_enable(struct cxl_dev_state *cxlds, u16 val)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
@@ -191,8 +201,10 @@ static int cxl_set_mem_enable(struct cxl_dev_state *cxlds, u16 val)
if (rc)
return pcibios_err_to_errno(rc);
- if ((ctrl & PCI_DVSEC_CXL_MEM_ENABLE) == val)
+ if ((ctrl & PCI_DVSEC_CXL_MEM_ENABLE) == val) {
+ cxl_hdm_cache_dvsec_ctrl(pdev, ctrl);
return 1;
+ }
ctrl &= ~PCI_DVSEC_CXL_MEM_ENABLE;
ctrl |= val;
@@ -200,6 +212,7 @@ static int cxl_set_mem_enable(struct cxl_dev_state *cxlds, u16 val)
if (rc)
return pcibios_err_to_errno(rc);
+ cxl_hdm_cache_dvsec_ctrl(pdev, ctrl);
return 0;
}
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index 20c2d9fbcfe7..ba1f942d20e1 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -200,6 +200,7 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
return ret_val;
}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_iomap_block, "CXL");
int cxl_map_component_regs(const struct cxl_register_map *map,
struct cxl_component_regs *regs,
@@ -285,6 +286,8 @@ static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
}
map->reg_type = reg_type;
+ map->bar = bar;
+ map->bar_offset = offset;
map->resource = pci_resource_start(pdev, bar) + offset;
map->max_size = pci_resource_len(pdev, bar) - offset;
return true;
@@ -309,6 +312,7 @@ static int __cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_ty
*map = (struct cxl_register_map) {
.host = &pdev->dev,
.resource = CXL_RESOURCE_NONE,
+ .bar = -1,
};
regloc = pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_CXL,
@@ -339,6 +343,8 @@ static int __cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_ty
}
map->resource = CXL_RESOURCE_NONE;
+ map->bar = -1;
+ map->bar_offset = 0;
if (index == CXL_INSTANCES_COUNT)
return instance;
@@ -518,6 +524,7 @@ u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb)
return offset;
}
+EXPORT_SYMBOL_NS_GPL(cxl_rcrb_to_aer, "CXL");
static resource_size_t cxl_rcrb_to_linkcap(struct device *dev, struct cxl_dport *dport)
{
@@ -634,6 +641,7 @@ resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri
return component_reg_phys;
}
+EXPORT_SYMBOL_NS_GPL(__rcrb_to_component, "CXL");
resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
struct cxl_dport *dport)
@@ -642,3 +650,4 @@ resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
return CXL_RESOURCE_NONE;
return __rcrb_to_component(dev, &dport->rcrb, CXL_RCRB_UPSTREAM);
}
+EXPORT_SYMBOL_NS_GPL(cxl_rcd_component_reg_phys, "CXL");
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 8d2fbc49a06f..c3f53c1b93fd 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -2,9 +2,17 @@
/* Copyright (c) 2026 NVIDIA Corporation & Affiliates */
#include <linux/delay.h>
#include <linux/bug.h>
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
#include <linux/errno.h>
#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include <cxl/pci.h>
#include "cxl.h"
#include "core.h"
@@ -166,3 +174,272 @@ int cxl_hdm_unpack_decoder(struct cxl_decoder_settings *settings, int id,
return 0;
}
EXPORT_SYMBOL_FOR_MODULES(cxl_hdm_unpack_decoder, "cxl_core");
+
+static int cxl_pci_hdm_dvsec(struct pci_dev *pdev)
+{
+ u16 cap;
+ int dvsec;
+ int rc;
+
+ dvsec = pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_CXL,
+ PCI_DVSEC_CXL_DEVICE);
+ if (!dvsec)
+ return -ENXIO;
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CAP, &cap);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (!(cap & PCI_DVSEC_CXL_MEM_CAPABLE) ||
+ !FIELD_GET(PCI_DVSEC_CXL_HDM_COUNT, cap))
+ return -ENXIO;
+
+ return dvsec;
+}
+
+static int cxl_pci_hdm_read_decoder(struct pci_dev *pdev,
+ struct cxl_decoder_settings *settings,
+ void __iomem *hdm, int id)
+{
+ u64 target_or_skip, base, size;
+ u32 ctrl;
+ int rc;
+
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ base = ((u64)readl(hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id)) << 32) |
+ readl(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
+ size = ((u64)readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id)) << 32) |
+ readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
+ target_or_skip =
+ ((u64)readl(hdm + CXL_HDM_DECODER0_TL_HIGH(id)) << 32) |
+ readl(hdm + CXL_HDM_DECODER0_TL_LOW(id));
+
+ rc = cxl_hdm_unpack_decoder(settings, id, ctrl, base, size,
+ target_or_skip);
+ if (rc) {
+ pci_err(pdev,
+ "CXL HDM decoder %d has invalid configuration: %d\n",
+ id, rc);
+ return rc;
+ }
+
+ if (!(settings->config.flags & CXL_DECODER_F_ENABLE))
+ *settings = (struct cxl_decoder_settings) {
+ .config.id = id,
+ };
+
+ return 0;
+}
+
+static void __iomem *cxl_pci_hdm_map_regs(struct pci_dev *pdev,
+ struct cxl_register_map *map,
+ resource_size_t *hdm_offset,
+ int *decoder_count)
+{
+ struct cxl_reg_map *hdm_map = &map->component_map.hdm_decoder;
+ void __iomem *hdm;
+ size_t required;
+ int rc;
+
+ /* cxl_setup_regs() populates hdm_map, including its valid bit. */
+ rc = cxl_setup_regs(map);
+ if (rc)
+ return ERR_PTR(rc);
+ if (!hdm_map->valid)
+ return ERR_PTR(-ENODEV);
+ if (hdm_map->offset > map->max_size ||
+ hdm_map->size > map->max_size - hdm_map->offset)
+ return ERR_PTR(-ENXIO);
+ if (check_add_overflow(map->bar_offset,
+ (resource_size_t)hdm_map->offset, hdm_offset))
+ return ERR_PTR(-EOVERFLOW);
+
+ hdm = ioremap(map->resource + hdm_map->offset, hdm_map->size);
+ if (!hdm)
+ return ERR_PTR(-ENOMEM);
+
+ *decoder_count =
+ cxl_hdm_decoder_count(readl(hdm + CXL_HDM_DECODER_CAP_OFFSET));
+ if (*decoder_count < 0) {
+ iounmap(hdm);
+ return ERR_PTR(*decoder_count);
+ }
+
+ /* The last decoder's target-list high register must fit in the mapping. */
+ required = CXL_HDM_DECODER0_TL_HIGH(*decoder_count - 1) + sizeof(u32);
+ if (required > hdm_map->size) {
+ pci_err(pdev,
+ "CXL HDM decoder count exceeds mapped register block\n");
+ iounmap(hdm);
+ return ERR_PTR(-ENXIO);
+ }
+
+ return hdm;
+}
+
+static struct cxl_hdm_info *__cxl_pci_hdm_read_info(struct pci_dev *pdev,
+ struct cxl_register_map *map,
+ int dvsec)
+{
+ struct cxl_reg_map *hdm_map = &map->component_map.hdm_decoder;
+ resource_size_t hdm_offset;
+ void __iomem *hdm;
+ int decoder_count;
+ u16 dvsec_ctrl;
+ int rc;
+
+ hdm = cxl_pci_hdm_map_regs(pdev, map, &hdm_offset, &decoder_count);
+ if (IS_ERR(hdm))
+ return ERR_CAST(hdm);
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL,
+ &dvsec_ctrl);
+ if (rc) {
+ rc = pcibios_err_to_errno(rc);
+ goto out_unmap;
+ }
+
+ struct cxl_hdm_info *info =
+ kzalloc_flex(*info, settings, decoder_count, GFP_KERNEL);
+ if (!info) {
+ rc = -ENOMEM;
+ goto out_unmap;
+ }
+
+ info->decoder_count = decoder_count;
+ info->hdm_bar = map->bar;
+ info->hdm_offset = hdm_offset;
+ info->hdm_size = hdm_map->size;
+ info->global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+ info->dvsec_ctrl = dvsec_ctrl;
+ info->dvsec_ctrl_valid = true;
+
+ for (int i = 0; i < decoder_count; i++) {
+ rc = cxl_pci_hdm_read_decoder(pdev, &info->settings[i], hdm, i);
+ if (rc)
+ goto out_free;
+ }
+
+ /*
+ * A changed decoder count means the snapshot no longer describes the
+ * complete hardware state. Reject it rather than publish a partial cache.
+ */
+ rc = cxl_hdm_decoder_count(readl(hdm + CXL_HDM_DECODER_CAP_OFFSET));
+ if (rc != decoder_count) {
+ pci_err(pdev, "CXL HDM decoder count changed from %d to %d\n",
+ decoder_count, rc);
+ rc = -ENXIO;
+ goto out_free;
+ }
+
+ iounmap(hdm);
+ return info;
+
+out_free:
+ kfree(info);
+out_unmap:
+ iounmap(hdm);
+ return ERR_PTR(rc);
+}
+
+static struct cxl_hdm_info *cxl_pci_hdm_read_info(struct pci_dev *pdev,
+ struct cxl_register_map *map,
+ int dvsec)
+{
+ struct cxl_hdm_info *info;
+ u16 command;
+ int rc;
+
+ guard(pci_dev)(pdev);
+
+ rc = pci_read_config_word(pdev, PCI_COMMAND, &command);
+ if (rc)
+ return ERR_PTR(pcibios_err_to_errno(rc));
+
+ if (command & PCI_COMMAND_MEMORY)
+ return __cxl_pci_hdm_read_info(pdev, map, dvsec);
+
+ rc = pci_write_config_word(pdev, PCI_COMMAND,
+ command | PCI_COMMAND_MEMORY);
+ if (rc)
+ return ERR_PTR(pcibios_err_to_errno(rc));
+
+ info = __cxl_pci_hdm_read_info(pdev, map, dvsec);
+ rc = pci_write_config_word(pdev, PCI_COMMAND, command);
+ if (!rc)
+ return info;
+
+ if (IS_ERR(info)) {
+ pci_err(pdev,
+ "failed to restore PCI_COMMAND after CXL HDM cache init: %d\n",
+ pcibios_err_to_errno(rc));
+ return info;
+ }
+
+ kfree(info);
+ return ERR_PTR(pcibios_err_to_errno(rc));
+}
+
+static int __pci_cxl_hdm_cache_init(struct pci_dev *pdev)
+{
+ struct cxl_register_map map = { };
+ struct resource *bar;
+ int dvsec;
+ int rc;
+
+ /* Avoid duplicate MMIO reads when the cache is already present. */
+ scoped_guard(rwsem_read, &cxl_rwsem.dpa)
+ if (pdev->hdm)
+ return 0;
+
+ dvsec = cxl_pci_hdm_dvsec(pdev);
+ if (dvsec == -ENXIO)
+ return 0;
+ if (dvsec < 0)
+ return dvsec;
+
+ rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
+ if (rc)
+ return rc;
+ if (map.bar < 0 || map.bar >= PCI_STD_NUM_BARS)
+ return -ENODEV;
+
+ bar = &pdev->resource[map.bar];
+ if (!pci_resource_len(pdev, map.bar) ||
+ (bar->flags & (IORESOURCE_UNSET | IORESOURCE_DISABLED)) ||
+ resource_type(bar) != IORESOURCE_MEM || !bar->start || !bar->end)
+ return -ENODEV;
+
+ struct cxl_hdm_info *read_info =
+ cxl_pci_hdm_read_info(pdev, &map, dvsec);
+ if (IS_ERR(read_info))
+ return PTR_ERR(read_info);
+
+ struct cxl_hdm_info *info __free(kfree) = read_info;
+ guard(rwsem_write)(&cxl_rwsem.dpa);
+ /* Another initializer may have published while we read MMIO. */
+ if (!pdev->hdm)
+ pdev->hdm = no_free_ptr(info);
+
+ return 0;
+}
+
+void pci_cxl_hdm_cache_init(struct pci_dev *pdev)
+{
+ int rc;
+
+ rc = __pci_cxl_hdm_cache_init(pdev);
+ if (rc)
+ pci_dbg(pdev, "CXL HDM cache init failed: %d\n", rc);
+}
+EXPORT_SYMBOL_FOR_MODULES(pci_cxl_hdm_cache_init, "cxl_core");
+
+void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
+{
+ struct cxl_hdm_info *info;
+
+ guard(rwsem_write)(&cxl_rwsem.dpa);
+ info = pdev->hdm;
+ /* Unpublish before freeing so subsequent readers cannot use stale state. */
+ pdev->hdm = NULL;
+ kfree(info);
+}
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 655ed53436d3..d866452222b6 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -18,6 +18,7 @@
#include <linux/pm_runtime.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
+#include <cxl/cxl.h>
#include "pci.h"
@@ -359,6 +360,7 @@ void pci_bus_add_device(struct pci_dev *dev)
/* Save config space for error recoverability */
pci_save_state(dev);
+ pci_cxl_hdm_cache_init(dev);
/*
* Enable runtime PM, which potentially allows the device to
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 27008e2ea5af..752347464a4d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -24,6 +24,7 @@
#include <linux/pm_runtime.h>
#include <linux/bitfield.h>
#include <trace/events/pci.h>
+#include <cxl/cxl.h>
#include "pci.h"
static struct resource busn_resource = {
@@ -2484,6 +2485,7 @@ static void pci_release_dev(struct device *dev)
struct pci_dev *pci_dev;
pci_dev = to_pci_dev(dev);
+ pci_cxl_hdm_cache_release(pci_dev);
pci_release_capabilities(pci_dev);
pci_release_of_node(pci_dev);
pcibios_release_device(pci_dev);
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index e200c5c56b92..a1c63e031dd4 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -26,6 +26,7 @@ enum cxl_devtype {
};
struct cxl_region;
+struct pci_dev;
enum cxl_decoder_type {
CXL_DECODER_DEVMEM = 2,
@@ -92,6 +93,9 @@ struct cxl_decoder_settings {
* @dvsec_ctrl: CXL DVSEC control register
* @dvsec_ctrl_valid: whether @dvsec_ctrl contains valid state
* @settings: per-decoder programming state
+ *
+ * Publication through pci_dev.hdm and all mutable fields are protected by
+ * cxl_rwsem.dpa.
*/
struct cxl_hdm_info {
int decoder_count;
@@ -177,6 +181,8 @@ struct cxl_pmu_reg_map {
* @base: virtual base of the register-block-BAR + @block_offset
* @resource: physical resource base of the register block
* @max_size: maximum mapping size to perform register search
+ * @bar: PCI BAR containing the register block
+ * @bar_offset: register block offset relative to @bar
* @reg_type: see enum cxl_regloc_type
* @component_map: cxl_reg_map for component registers
* @device_map: cxl_reg_maps for device registers
@@ -187,6 +193,8 @@ struct cxl_register_map {
void __iomem *base;
resource_size_t resource;
resource_size_t max_size;
+ int bar;
+ resource_size_t bar_offset;
u8 reg_type;
union {
struct cxl_component_reg_map component_map;
@@ -195,6 +203,19 @@ struct cxl_register_map {
};
};
+#ifdef CONFIG_CXL_RESET
+void pci_cxl_hdm_cache_init(struct pci_dev *pdev);
+void pci_cxl_hdm_cache_release(struct pci_dev *pdev);
+#else
+static inline void pci_cxl_hdm_cache_init(struct pci_dev *pdev)
+{
+}
+
+static inline void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
+{
+}
+#endif
+
/**
* struct cxl_dpa_perf - DPA performance property entry
* @dpa_range: range for DPA address
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 2be1df80fcc9..e80500f457a9 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -55,7 +55,6 @@ obj-m += cxl_core.o
cxl_core-y := $(CXL_CORE_SRC)/port.o
cxl_core-y += $(CXL_CORE_SRC)/pmem.o
-cxl_core-y += $(CXL_CORE_SRC)/regs.o
cxl_core-y += $(CXL_CORE_SRC)/memdev.o
cxl_core-y += $(CXL_CORE_SRC)/mbox.o
cxl_core-y += $(CXL_CORE_SRC)/pci.o
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 11/16] cxl: Add CXL Device Reset sequencing
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (9 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 10/16] cxl: Cache endpoint HDM state during PCI enumeration Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 12/16] cxl: Validate and synchronize HDM ranges around reset Srirangan Madhavan
` (4 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Implement CXL Device Reset for eligible Type 2 devices: disable CXL.cache,
perform supported writeback, drain transactions, prepare the IOMMU,
initiate reset with Memory Clear enabled, and wait for completion.
Observe the 100 ms post-reset quiet period before polling Status2, and
treat an all-ones read as not ready. Treat Control2 command bits as
transient state, restore cache policy on exit, preserve the primary error,
and abort when IOMMU preparation fails.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 252 ++++++++++++++++++++++++++++++++++
include/cxl/cxl.h | 7 +
include/uapi/linux/pci_regs.h | 14 ++
3 files changed, 273 insertions(+)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index c3f53c1b93fd..94f854520a1c 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -8,6 +8,8 @@
#include <linux/export.h>
#include <linux/io.h>
#include <linux/ioport.h>
+#include <linux/iommu.h>
+#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
@@ -443,3 +445,253 @@ void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
pdev->hdm = NULL;
kfree(info);
}
+
+/*
+ * CXL r4.0 sec 9.7.2 defines the reset completion timeout encodings.
+ * Sec 9.7.3 leaves config-space access behavior undefined for 100 ms after
+ * initiating CXL Reset, then limits software to CXL Status2 access until
+ * reset completion, timeout, or error.
+ */
+#define CXL_RESET_RRS_WAIT_MS 100
+#define CXL_RESET_STATUS_POLL_MS 20
+#define CXL_RESET_MAX_WAIT_MS 20000
+static const u32 cxl_reset_timeout_ms[] = {
+ 10, 100, 1000, 10000, 100000,
+};
+
+#define CXL_CACHE_WBI_TIMEOUT_US 100000
+#define CXL_CACHE_WBI_POLL_US 100
+
+#define CXL_RESET_CTRL2_CMD_MASK \
+ (PCI_DVSEC_CXL_INIT_CACHE_WBI | PCI_DVSEC_CXL_INIT_CXL_RST)
+
+static int cxl_reset_update_ctrl2_no_replay(struct pci_dev *pdev, int dvsec,
+ u16 set, u16 clear)
+{
+ u16 ctrl2;
+ int rc;
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, &ctrl2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(ctrl2))
+ return -ENODEV;
+
+ /*
+ * INIT_CACHE_WBI and INIT_CXL_RST are commands. Do not replay a command
+ * that remains set in the value read back while updating persistent
+ * Control2 state.
+ */
+ ctrl2 &= ~CXL_RESET_CTRL2_CMD_MASK;
+ ctrl2 &= ~clear;
+ ctrl2 |= set;
+
+ rc = pci_write_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, ctrl2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+
+ return 0;
+}
+
+static int cxl_reset_wait_cache_wbi(struct pci_dev *pdev, int dvsec)
+{
+ unsigned long deadline;
+ u16 status2;
+ int rc;
+
+ rc = cxl_reset_update_ctrl2_no_replay(pdev, dvsec,
+ PCI_DVSEC_CXL_INIT_CACHE_WBI, 0);
+ if (rc)
+ return rc;
+
+ deadline = jiffies + usecs_to_jiffies(CXL_CACHE_WBI_TIMEOUT_US);
+ while (time_before(jiffies, deadline)) {
+ usleep_range(CXL_CACHE_WBI_POLL_US,
+ CXL_CACHE_WBI_POLL_US * 2);
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_STATUS2,
+ &status2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(status2))
+ return -ENODEV;
+ if (status2 & PCI_DVSEC_CXL_CACHE_INV)
+ return 0;
+ }
+
+ /* Do not miss completion concurrent with the polling deadline. */
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_STATUS2,
+ &status2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(status2))
+ return -ENODEV;
+ if (status2 & PCI_DVSEC_CXL_CACHE_INV)
+ return 0;
+
+ return -ETIMEDOUT;
+}
+
+static int cxl_reset_disable_cache(struct pci_dev *pdev, int dvsec, u16 cap)
+{
+ int rc;
+
+ rc = cxl_reset_update_ctrl2_no_replay(pdev, dvsec,
+ PCI_DVSEC_CXL_DISABLE_CACHING, 0);
+ if (rc || !(cap & PCI_DVSEC_CXL_CACHE_WBI_CAPABLE))
+ return rc;
+
+ return cxl_reset_wait_cache_wbi(pdev, dvsec);
+}
+
+static int cxl_reset_restore_cache_policy(struct pci_dev *pdev, int dvsec,
+ u16 saved_ctrl2)
+{
+ int rc;
+
+ rc = cxl_reset_update_ctrl2_no_replay(pdev, dvsec,
+ saved_ctrl2 & PCI_DVSEC_CXL_DISABLE_CACHING,
+ PCI_DVSEC_CXL_DISABLE_CACHING);
+ if (rc)
+ pci_err(pdev, "failed to restore CXL cache policy: %d\n", rc);
+
+ return rc;
+}
+
+static int cxl_reset_wait_done(struct pci_dev *pdev, int dvsec, u16 cap)
+{
+ unsigned long deadline;
+ u32 timeout_ms;
+ u16 status2;
+ int idx, rc;
+
+ idx = FIELD_GET(PCI_DVSEC_CXL_RST_TIMEOUT, cap);
+ if (idx >= ARRAY_SIZE(cxl_reset_timeout_ms)) {
+ pci_warn(pdev,
+ "unknown CXL reset timeout encoding %d; using %u ms\n",
+ idx, CXL_RESET_MAX_WAIT_MS);
+ idx = ARRAY_SIZE(cxl_reset_timeout_ms) - 1;
+ }
+
+ /* Allow one retry after the mandatory 100 ms quiet period. */
+ timeout_ms = clamp_t(u32, cxl_reset_timeout_ms[idx],
+ CXL_RESET_RRS_WAIT_MS + CXL_RESET_STATUS_POLL_MS,
+ CXL_RESET_MAX_WAIT_MS);
+ msleep(CXL_RESET_RRS_WAIT_MS);
+ deadline = jiffies + msecs_to_jiffies(timeout_ms -
+ CXL_RESET_RRS_WAIT_MS);
+
+ for (;;) {
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_STATUS2,
+ &status2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (status2 != U16_MAX) {
+ if (status2 & PCI_DVSEC_CXL_RST_ERR)
+ return -EIO;
+ if (status2 & PCI_DVSEC_CXL_RST_DONE)
+ return 0;
+ }
+
+ if (time_after_eq(jiffies, deadline))
+ return -ETIMEDOUT;
+
+ msleep(CXL_RESET_STATUS_POLL_MS);
+ }
+}
+
+static int cxl_clear_memory(struct pci_dev *pdev, int dvsec, bool initiate)
+{
+ if (initiate)
+ return cxl_reset_update_ctrl2_no_replay(pdev, dvsec,
+ PCI_DVSEC_CXL_INIT_CXL_RST |
+ PCI_DVSEC_CXL_RST_MEM_CLR_EN,
+ 0);
+
+ return cxl_reset_update_ctrl2_no_replay(pdev, dvsec, 0,
+ PCI_DVSEC_CXL_RST_MEM_CLR_EN);
+}
+
+static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
+{
+ int rc, rc2;
+
+ if (!pci_wait_for_pending_transaction(pdev)) {
+ pci_err(pdev, "timed out waiting for pending transactions\n");
+ return -ETIMEDOUT;
+ }
+
+ rc = pci_dev_reset_iommu_prepare(pdev);
+ if (rc) {
+ pci_err(pdev, "failed to stop IOMMU for CXL reset: %d\n", rc);
+ return rc;
+ }
+
+ rc = cxl_clear_memory(pdev, dvsec, true);
+ if (!rc)
+ rc = cxl_reset_wait_done(pdev, dvsec, cap);
+
+ /* Always clear Memory Clear; successful cleanup must not hide reset failure. */
+ rc2 = cxl_clear_memory(pdev, dvsec, false);
+ if (rc2)
+ pci_err(pdev, "failed to clear CXL Reset Memory Clear: %d\n", rc2);
+ rc = rc ?: rc2;
+
+ pci_dev_reset_iommu_done(pdev);
+ return rc;
+}
+
+static int cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
+{
+ u16 saved_ctrl2;
+ int rc, rc2;
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, &saved_ctrl2);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(saved_ctrl2))
+ return -ENODEV;
+
+ rc = cxl_reset_disable_cache(pdev, dvsec, cap);
+ if (!rc)
+ rc = __cxl_reset_execute(pdev, dvsec, cap);
+ /* Restore cache policy after any attempt to disable caching. */
+ rc2 = cxl_reset_restore_cache_policy(pdev, dvsec, saved_ctrl2);
+ return rc ?: rc2;
+}
+
+int cxl_reset_function(struct pci_dev *pdev, bool probe)
+{
+ int dvsec, rc;
+ u16 cap, ctrl;
+
+ dvsec = pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_CXL,
+ PCI_DVSEC_CXL_DEVICE);
+ if (!dvsec)
+ return -ENOTTY;
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CAP, &cap);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(cap))
+ return -ENODEV;
+ if (!(cap & PCI_DVSEC_CXL_CACHE_CAPABLE) ||
+ !(cap & PCI_DVSEC_CXL_MEM_CAPABLE) ||
+ !(cap & PCI_DVSEC_CXL_RST_CAPABLE) ||
+ !(cap & PCI_DVSEC_CXL_RST_MEM_CLR_CAPABLE))
+ return -ENOTTY;
+
+ rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL, &ctrl);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(ctrl))
+ return -ENODEV;
+ if (!(ctrl & PCI_DVSEC_CXL_CACHE_ENABLE) ||
+ !(ctrl & PCI_DVSEC_CXL_MEM_ENABLE))
+ return -ENOTTY;
+
+ if (probe)
+ return 0;
+
+ return cxl_reset_execute(pdev, dvsec, cap);
+}
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index a1c63e031dd4..9904eaed5af1 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -6,6 +6,7 @@
#define __CXL_CXL_H__
#include <linux/device.h>
+#include <linux/errno.h>
#include <linux/node.h>
#include <linux/ioport.h>
#include <linux/range.h>
@@ -206,6 +207,7 @@ struct cxl_register_map {
#ifdef CONFIG_CXL_RESET
void pci_cxl_hdm_cache_init(struct pci_dev *pdev);
void pci_cxl_hdm_cache_release(struct pci_dev *pdev);
+int cxl_reset_function(struct pci_dev *pdev, bool probe);
#else
static inline void pci_cxl_hdm_cache_init(struct pci_dev *pdev)
{
@@ -214,6 +216,11 @@ static inline void pci_cxl_hdm_cache_init(struct pci_dev *pdev)
static inline void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
{
}
+
+static inline int cxl_reset_function(struct pci_dev *pdev, bool probe)
+{
+ return -ENOTTY;
+}
#endif
/**
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index facaa324bd86..7224857c7b30 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -1352,8 +1352,22 @@
#define PCI_DVSEC_CXL_CACHE_CAPABLE _BITUL(0)
#define PCI_DVSEC_CXL_MEM_CAPABLE _BITUL(2)
#define PCI_DVSEC_CXL_HDM_COUNT __GENMASK(5, 4)
+#define PCI_DVSEC_CXL_CACHE_WBI_CAPABLE _BITUL(6)
+#define PCI_DVSEC_CXL_RST_CAPABLE _BITUL(7)
+#define PCI_DVSEC_CXL_RST_TIMEOUT __GENMASK(10, 8)
+#define PCI_DVSEC_CXL_RST_MEM_CLR_CAPABLE _BITUL(11)
#define PCI_DVSEC_CXL_CTRL 0xC
+#define PCI_DVSEC_CXL_CACHE_ENABLE _BITUL(0)
#define PCI_DVSEC_CXL_MEM_ENABLE _BITUL(2)
+#define PCI_DVSEC_CXL_CTRL2 0x10
+#define PCI_DVSEC_CXL_DISABLE_CACHING _BITUL(0)
+#define PCI_DVSEC_CXL_INIT_CACHE_WBI _BITUL(1)
+#define PCI_DVSEC_CXL_INIT_CXL_RST _BITUL(2)
+#define PCI_DVSEC_CXL_RST_MEM_CLR_EN _BITUL(3)
+#define PCI_DVSEC_CXL_STATUS2 0x12
+#define PCI_DVSEC_CXL_CACHE_INV _BITUL(0)
+#define PCI_DVSEC_CXL_RST_DONE _BITUL(1)
+#define PCI_DVSEC_CXL_RST_ERR _BITUL(2)
#define PCI_DVSEC_CXL_RANGE_SIZE_HIGH(i) (0x18 + (i * 0x10))
#define PCI_DVSEC_CXL_RANGE_SIZE_LOW(i) (0x1C + (i * 0x10))
#define PCI_DVSEC_CXL_MEM_INFO_VALID _BITUL(0)
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 12/16] cxl: Validate and synchronize HDM ranges around reset
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (10 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 11/16] cxl: Add CXL Device Reset sequencing Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 13/16] PCI/CXL: Reject reset with unsafe function scope Srirangan Madhavan
` (3 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Refuse reset unless enabled system-physical HDM ranges can be reserved
exclusively and CPU-cache invalidation is available. Invalidate before
reset and again before ending IOMMU exclusion, holding range reservations
until the second invalidation completes. A later patch places state
restoration before the second invalidation.
Reject normalized-addressing decoders because their cached ranges are not
system physical addresses. Ignore zero-size decoders because they map no
address range.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 248 +++++++++++++++++++++++++++++++++++-
1 file changed, 241 insertions(+), 7 deletions(-)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 94f854520a1c..584b51cd9e28 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -11,6 +11,8 @@
#include <linux/iommu.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/memregion.h>
#include <linux/pci.h>
#include <linux/slab.h>
@@ -462,6 +464,205 @@ static const u32 cxl_reset_timeout_ms[] = {
#define CXL_CACHE_WBI_TIMEOUT_US 100000
#define CXL_CACHE_WBI_POLL_US 100
+struct cxl_hdm_range {
+ struct list_head list;
+ struct pci_dev *pdev;
+ struct range hpa_range;
+ u64 len;
+ struct resource *res;
+};
+
+struct cxl_hdm_range_context {
+ struct list_head ranges;
+};
+
+static void cxl_hdm_range_context_destroy(struct cxl_hdm_range_context *ctx)
+{
+ struct cxl_hdm_range *range, *next;
+
+ list_for_each_entry_safe(range, next, &ctx->ranges, list) {
+ list_del(&range->list);
+ if (range->res)
+ release_mem_region(range->hpa_range.start,
+ resource_size(range->res));
+ kfree(range);
+ }
+}
+
+/*
+ * Bound the range twice: request_mem_region() takes resource_size_t while
+ * cpu_cache_invalidate_memregion() takes size_t, and the two differ on
+ * 32-bit builds with CONFIG_PHYS_ADDR_T_64BIT. range_len() can also reach
+ * RESOURCE_SIZE_MAX + 1 for a full-width range, and wraps to zero when
+ * resource_size_t is 64-bit, which the !len test catches.
+ */
+static int cxl_hdm_range_validate(struct pci_dev *pdev,
+ const struct range *hpa_range)
+{
+ u64 len = range_len(hpa_range);
+
+ if (!len)
+ return -EINVAL;
+
+ if (hpa_range->end > RESOURCE_SIZE_MAX) {
+ pci_err(pdev,
+ "CXL reset range [%#llx-%#llx] exceeds resource address size\n",
+ hpa_range->start, hpa_range->end);
+ return -EOVERFLOW;
+ }
+
+ if (len > RESOURCE_SIZE_MAX) {
+ pci_err(pdev,
+ "CXL reset range [%#llx-%#llx] exceeds resource size\n",
+ hpa_range->start, hpa_range->end);
+ return -EOVERFLOW;
+ }
+
+ if (len > SIZE_MAX) {
+ pci_err(pdev,
+ "CXL reset range [%#llx-%#llx] exceeds cache flush size\n",
+ hpa_range->start, hpa_range->end);
+ return -EOVERFLOW;
+ }
+
+ return 0;
+}
+
+static int cxl_hdm_range_add(struct cxl_hdm_range_context *ctx,
+ struct pci_dev *pdev, const struct range *hpa_range)
+{
+ struct cxl_hdm_range *range, *next, *new_range;
+ int rc;
+
+ rc = cxl_hdm_range_validate(pdev, hpa_range);
+ if (rc)
+ return rc;
+
+ list_for_each_entry(range, &ctx->ranges, list)
+ if (range_contains(&range->hpa_range, hpa_range))
+ return 0;
+
+ new_range = kzalloc_obj(*new_range);
+ if (!new_range)
+ return -ENOMEM;
+
+ new_range->pdev = pdev;
+ new_range->hpa_range = *hpa_range;
+ new_range->len = range_len(hpa_range);
+
+ list_for_each_entry_safe(range, next, &ctx->ranges, list) {
+ if (range_contains(hpa_range, &range->hpa_range)) {
+ list_del(&range->list);
+ kfree(range);
+ }
+ }
+ list_add_tail(&new_range->list, &ctx->ranges);
+
+ return 0;
+}
+
+static int cxl_hdm_ranges_collect(struct cxl_hdm_range_context *ctx,
+ struct pci_dev *pdev)
+{
+ struct cxl_hdm_info *info;
+ int rc;
+
+ guard(rwsem_read)(&cxl_rwsem.dpa);
+ info = pdev->hdm;
+ if (!info) {
+ pci_err(pdev, "CXL HDM decoder state unavailable\n");
+ return -ENXIO;
+ }
+
+ for (int i = 0; i < info->decoder_count; i++) {
+ struct cxl_decoder_config *config = &info->settings[i].config;
+
+ /* A committed zero-size decoder maps no HPA. */
+ if (!(config->flags & CXL_DECODER_F_ENABLE) ||
+ !range_len(&config->hpa_range))
+ continue;
+
+ if (config->flags & CXL_DECODER_F_NORMALIZED_ADDRESSING) {
+ pci_err(pdev,
+ "CXL reset does not support normalized address decoders\n");
+ return -EOPNOTSUPP;
+ }
+
+ rc = cxl_hdm_range_add(ctx, pdev, &config->hpa_range);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+static int cxl_hdm_ranges_request(struct cxl_hdm_range_context *ctx)
+{
+ struct cxl_hdm_range *range;
+
+ lockdep_assert_held_write(&cxl_rwsem.region);
+
+ list_for_each_entry(range, &ctx->ranges, list) {
+ const struct range *hpa_range = &range->hpa_range;
+
+ range->res = request_mem_region(hpa_range->start, range->len,
+ "cxl_reset");
+ if (!range->res) {
+ pci_err(range->pdev,
+ "cannot reset while CXL memory range is busy [%#llx-%#llx]\n",
+ hpa_range->start, hpa_range->end);
+ return -EBUSY;
+ }
+ }
+
+ return 0;
+}
+
+static int cxl_hdm_ranges_invalidate(struct cxl_hdm_range_context *ctx)
+{
+ struct cxl_hdm_range *range;
+ int rc = 0;
+
+ lockdep_assert_held_write(&cxl_rwsem.region);
+
+ list_for_each_entry(range, &ctx->ranges, list) {
+ const struct range *hpa_range = &range->hpa_range;
+ int rc2;
+
+ rc2 = cpu_cache_invalidate_memregion(hpa_range->start, range->len);
+ if (rc2)
+ pci_err(range->pdev,
+ "failed to invalidate CPU cache [%#llx-%#llx]: %d\n",
+ hpa_range->start, hpa_range->end, rc2);
+ rc = rc ?: rc2;
+ }
+
+ return rc;
+}
+
+static int cxl_hdm_ranges_prepare(struct cxl_hdm_range_context *ctx,
+ struct pci_dev *pdev)
+{
+ int rc;
+
+ lockdep_assert_held_write(&cxl_rwsem.region);
+
+ if (!cpu_cache_has_invalidate_memregion()) {
+ pci_err(pdev, "CPU cache invalidation unavailable\n");
+ return -ENXIO;
+ }
+
+ rc = cxl_hdm_ranges_collect(ctx, pdev);
+ if (rc)
+ return rc;
+
+ rc = cxl_hdm_ranges_request(ctx);
+ if (rc)
+ return rc;
+
+ return cxl_hdm_ranges_invalidate(ctx);
+}
+
#define CXL_RESET_CTRL2_CMD_MASK \
(PCI_DVSEC_CXL_INIT_CACHE_WBI | PCI_DVSEC_CXL_INIT_CXL_RST)
@@ -612,7 +813,8 @@ static int cxl_clear_memory(struct pci_dev *pdev, int dvsec, bool initiate)
PCI_DVSEC_CXL_RST_MEM_CLR_EN);
}
-static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
+static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap,
+ struct cxl_hdm_range_context *range_ctx)
{
int rc, rc2;
@@ -637,31 +839,42 @@ static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
pci_err(pdev, "failed to clear CXL Reset Memory Clear: %d\n", rc2);
rc = rc ?: rc2;
+ /* Evict lines fetched during reset before ending DMA exclusion. */
+ rc2 = cxl_hdm_ranges_invalidate(range_ctx);
+ rc = rc ?: rc2;
+
pci_dev_reset_iommu_done(pdev);
return rc;
}
-static int cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
+static int cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap,
+ struct cxl_hdm_range_context *range_ctx)
{
u16 saved_ctrl2;
int rc, rc2;
rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, &saved_ctrl2);
if (rc)
- return pcibios_err_to_errno(rc);
- if (PCI_POSSIBLE_ERROR(saved_ctrl2))
- return -ENODEV;
+ rc = pcibios_err_to_errno(rc);
+ else if (PCI_POSSIBLE_ERROR(saved_ctrl2))
+ rc = -ENODEV;
+ if (rc) {
+ cxl_hdm_range_context_destroy(range_ctx);
+ return rc;
+ }
rc = cxl_reset_disable_cache(pdev, dvsec, cap);
if (!rc)
- rc = __cxl_reset_execute(pdev, dvsec, cap);
+ rc = __cxl_reset_execute(pdev, dvsec, cap, range_ctx);
/* Restore cache policy after any attempt to disable caching. */
rc2 = cxl_reset_restore_cache_policy(pdev, dvsec, saved_ctrl2);
+ cxl_hdm_range_context_destroy(range_ctx);
return rc ?: rc2;
}
int cxl_reset_function(struct pci_dev *pdev, bool probe)
{
+ struct cxl_hdm_range_context range_ctx;
int dvsec, rc;
u16 cap, ctrl;
@@ -693,5 +906,26 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
if (probe)
return 0;
- return cxl_reset_execute(pdev, dvsec, cap);
+ /* The cache is owned by @pdev and does not require a bound CXL driver. */
+ scoped_guard(rwsem_read, &cxl_rwsem.dpa)
+ if (!pdev->hdm || !pdev->hdm->hdm_size)
+ return -ENOTTY;
+
+ if (!cpu_cache_has_invalidate_memregion())
+ return -ENOTTY;
+
+ INIT_LIST_HEAD(&range_ctx.ranges);
+
+ scoped_guard(rwsem_write, &cxl_rwsem.region) {
+ rc = cxl_hdm_ranges_prepare(&range_ctx, pdev);
+ if (rc) {
+ cxl_hdm_range_context_destroy(&range_ctx);
+ return rc;
+ }
+
+ /* cxl_reset_execute() releases the ranges on success and failure. */
+ rc = cxl_reset_execute(pdev, dvsec, cap, &range_ctx);
+ }
+
+ return rc;
}
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 13/16] PCI/CXL: Reject reset with unsafe function scope
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (11 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 12/16] cxl: Validate and synchronize HDM ranges around reset Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 14/16] cxl: Restore CXL state after PCI reset Srirangan Madhavan
` (2 subsequent siblings)
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
The per-device PCI reset interface must not reset sibling functions.
Reject cxl_reset and cxl_bus for multifunction devices and PFs with
enabled VFs.
Suggested-by: Alex Williamson <alwilliamson@nvidia.com>
Link: https://lore.kernel.org/linux-cxl/20260626160846.426e71b6@nvidia.com/
Link: https://lore.kernel.org/linux-cxl/6a50441e2bb5e_3cabcb1003e@djbw-dev.notmuch/
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 3 +++
drivers/pci/pci.c | 3 +++
2 files changed, 6 insertions(+)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 584b51cd9e28..679a605da24c 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -903,6 +903,9 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
!(ctrl & PCI_DVSEC_CXL_MEM_ENABLE))
return -ENOTTY;
+ if (pdev->multifunction || pci_num_vf(pdev))
+ return -ENOTTY;
+
if (probe)
return 0;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b2879a6be5f8..fe611340f5ab 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5026,6 +5026,9 @@ static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
if (!dvsec)
return -ENOTTY;
+ if (dev->multifunction || pci_num_vf(dev))
+ return -ENOTTY;
+
if (probe)
return 0;
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 14/16] cxl: Restore CXL state after PCI reset
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (12 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 13/16] PCI/CXL: Reject reset with unsafe function scope Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 15/16] PCI/CXL: Expose CXL Reset as a PCI reset method Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 16/16] PCI/CXL: Restore CXL state after CXL bus reset Srirangan Madhavan
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Restore the PCI configuration needed for HDM access, followed by cached
HDM decoder and CXL Device DVSEC state. Recommit a cleared locked decoder
before restoring its lock, but leave surviving locked state unchanged.
Stop at the first restoration failure and preserve a disabled PCI command
snapshot. Keep IOMMU exclusion active through restoration and post-reset
cache invalidation.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 418 +++++++++++++++++++++++++++++++++---
1 file changed, 392 insertions(+), 26 deletions(-)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 679a605da24c..0acc471d0d7e 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/memregion.h>
+#include <linux/overflow.h>
#include <linux/pci.h>
#include <linux/slab.h>
@@ -83,6 +84,26 @@ int cxld_await_commit(void __iomem *hdm, int id)
}
EXPORT_SYMBOL_FOR_MODULES(cxld_await_commit, "cxl_core");
+static int cxld_await_uncommit(void __iomem *hdm, int id)
+{
+ u32 ctrl;
+ int i;
+
+ for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
+ ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ return -EIO;
+ }
+ if (!FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
+ return 0;
+ fsleep(1000);
+ }
+
+ return -ETIMEDOUT;
+}
+
static void setup_hw_decoder(void __iomem *hdm,
struct cxl_decoder_settings *settings)
{
@@ -448,6 +469,335 @@ void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
kfree(info);
}
+static void __iomem *cxl_pci_hdm_ioremap_current(struct pci_dev *pdev,
+ int bar,
+ resource_size_t offset,
+ resource_size_t size)
+{
+ struct resource *res;
+ resource_size_t hdm_start;
+ void __iomem *hdm;
+
+ if (bar < 0 || bar >= PCI_STD_NUM_BARS || !size)
+ return ERR_PTR(-EINVAL);
+
+ res = &pdev->resource[bar];
+ if (!pci_resource_len(pdev, bar) ||
+ (res->flags & (IORESOURCE_UNSET | IORESOURCE_DISABLED)) ||
+ resource_type(res) != IORESOURCE_MEM || !res->start || !res->end)
+ return ERR_PTR(-ENODEV);
+ if (offset > resource_size(res) || size > resource_size(res) - offset)
+ return ERR_PTR(-ENODEV);
+ if (check_add_overflow(res->start, offset, &hdm_start))
+ return ERR_PTR(-EOVERFLOW);
+
+ hdm = ioremap(hdm_start, size);
+ if (!hdm) {
+ pci_err(pdev, "failed to remap CXL HDM decoder registers\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return hdm;
+}
+
+static int cxl_hdm_decoder_uncommit(struct pci_dev *pdev, void __iomem *hdm,
+ int id, bool *retained)
+{
+ u32 ctrl;
+ int rc;
+
+ *retained = false;
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+ if (PCI_POSSIBLE_ERROR(ctrl))
+ return -EIO;
+ if (ctrl & CXL_HDM_DECODER0_CTRL_COMMIT_ERROR) {
+ pci_err(pdev, "CXL HDM decoder %d has commit error set\n", id);
+ return -EIO;
+ }
+
+ if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK) {
+ if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED) {
+ *retained = true;
+ return 0;
+ }
+
+ pci_err(pdev, "CXL HDM decoder %d is locked and uncommitted\n",
+ id);
+ return -EIO;
+ }
+
+ if (!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED))
+ return 0;
+
+ ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+
+ rc = cxld_await_uncommit(hdm, id);
+ if (rc)
+ pci_err(pdev, "CXL HDM decoder %d uncommit failed: %d\n", id,
+ rc);
+
+ return rc;
+}
+
+static bool cxl_hdm_decoder_settings_match(
+ const struct cxl_decoder_settings *saved,
+ const struct cxl_decoder_settings *active)
+{
+ const struct cxl_decoder_config *a = &saved->config;
+ const struct cxl_decoder_config *b = &active->config;
+
+ return a->id == b->id &&
+ a->hpa_range.start == b->hpa_range.start &&
+ a->hpa_range.end == b->hpa_range.end &&
+ a->interleave_ways == b->interleave_ways &&
+ a->interleave_granularity == b->interleave_granularity &&
+ a->target_type == b->target_type &&
+ (a->flags & CXL_DECODER_F_RESET_MASK) ==
+ (b->flags & CXL_DECODER_F_RESET_MASK) &&
+ saved->target_or_skip_reg_val == active->target_or_skip_reg_val;
+}
+
+static int cxl_restore_hdm_decoder_commit(
+ void __iomem *hdm, struct cxl_decoder_settings *settings)
+{
+ guard(rwsem_read)(&cxl_rwsem.dpa);
+
+ cxl_commit_start(hdm, settings);
+ return cxld_await_commit(hdm, settings->config.id);
+}
+
+static int cxl_restore_hdm_decoder(struct pci_dev *pdev, void __iomem *hdm,
+ struct cxl_decoder_settings *settings)
+{
+ struct cxl_decoder_config *config = &settings->config;
+ bool retained;
+ u32 ctrl;
+ int rc;
+
+ rc = cxl_hdm_decoder_uncommit(pdev, hdm, config->id, &retained);
+ if (rc)
+ return rc;
+
+ if (retained) {
+ struct cxl_decoder_settings active;
+
+ rc = cxl_pci_hdm_read_decoder(pdev, &active, hdm,
+ config->id);
+ if (rc)
+ return rc;
+ if (!cxl_hdm_decoder_settings_match(settings, &active)) {
+ pci_err(pdev,
+ "CXL HDM decoder %d retained unexpected locked state\n",
+ config->id);
+ return -EIO;
+ }
+ return 0;
+ }
+
+ if (!(config->flags & CXL_DECODER_F_ENABLE))
+ return 0;
+
+ rc = cxl_restore_hdm_decoder_commit(hdm, settings);
+ if (rc) {
+ pci_err(pdev, "CXL HDM decoder %d restore failed: %d\n",
+ config->id, rc);
+ return rc;
+ }
+
+ if (!(config->flags & CXL_DECODER_F_LOCK))
+ return 0;
+
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(config->id));
+ if (PCI_POSSIBLE_ERROR(ctrl))
+ return -EIO;
+ ctrl |= CXL_HDM_DECODER0_CTRL_LOCK;
+ writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(config->id));
+
+ ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(config->id));
+ if (PCI_POSSIBLE_ERROR(ctrl) ||
+ !(ctrl & CXL_HDM_DECODER0_CTRL_LOCK)) {
+ pci_err(pdev, "CXL HDM decoder %d failed to restore lock\n",
+ config->id);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int cxl_snapshot_hdm(struct pci_dev *pdev,
+ struct cxl_hdm_info **snapshot)
+{
+ struct cxl_hdm_info *info;
+ size_t size;
+
+ guard(rwsem_read)(&cxl_rwsem.dpa);
+ info = pdev->hdm;
+ if (!info)
+ return -ENXIO;
+ if (info->decoder_count <= 0)
+ return -EINVAL;
+
+ size = struct_size(info, settings, info->decoder_count);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+ *snapshot = kmemdup(info, size, GFP_KERNEL);
+ if (!*snapshot)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void cxl_restore_pci_state_for_hdm_restore(struct pci_dev *pdev,
+ u16 *command)
+{
+ u32 saved_config = pdev->saved_config_space[PCI_COMMAND / 4];
+ u32 restore_config;
+
+ device_lock_assert(&pdev->dev);
+ *command = saved_config & 0xffff;
+
+ /*
+ * pci_restore_state() is the available interface for restoring BARs and
+ * related PCI state needed to reach HDM MMIO. Temporarily alter its saved
+ * command value so that it enables MSE but cannot enable BME or INTx
+ * before CXL state restoration completes. Preserve the original saved
+ * value for the outer PCI reset path.
+ */
+ restore_config = saved_config | PCI_COMMAND_MEMORY |
+ PCI_COMMAND_INTX_DISABLE;
+ restore_config &= ~PCI_COMMAND_MASTER;
+
+ pdev->saved_config_space[PCI_COMMAND / 4] = restore_config;
+ pci_restore_state(pdev);
+ pdev->saved_config_space[PCI_COMMAND / 4] = saved_config;
+}
+
+static int cxl_restore_dvsec_ctrl(struct pci_dev *pdev, u16 saved_ctrl)
+{
+ int dvsec;
+ int rc;
+
+ dvsec = pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_CXL,
+ PCI_DVSEC_CXL_DEVICE);
+ if (!dvsec)
+ return -ENOTTY;
+
+ rc = pci_write_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL,
+ saved_ctrl);
+ if (rc)
+ return pcibios_err_to_errno(rc);
+
+ return 0;
+}
+
+static int cxl_restore_hdm_state(struct pci_dev *pdev, void __iomem *hdm,
+ struct cxl_hdm_info *snapshot)
+{
+ int count;
+ int rc;
+
+ count = cxl_hdm_decoder_count(readl(hdm + CXL_HDM_DECODER_CAP_OFFSET));
+ if (count != snapshot->decoder_count) {
+ pci_err(pdev, "CXL HDM decoder count changed from %d to %d\n",
+ snapshot->decoder_count, count);
+ return -ENXIO;
+ }
+
+ /* Restore global HDM control before committing individual decoders. */
+ writel(snapshot->global_ctrl, hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+
+ for (int i = 0; i < snapshot->decoder_count; i++) {
+ rc = cxl_restore_hdm_decoder(pdev, hdm,
+ &snapshot->settings[i]);
+ if (rc)
+ return rc;
+ }
+
+ /* Flush posted HDM writes before restoring protocol enables. */
+ readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+
+ return 0;
+}
+
+static int cxl_restore_state(struct pci_dev *pdev,
+ struct cxl_hdm_info *snapshot)
+{
+ void __iomem *hdm;
+ int rc;
+
+ hdm = cxl_pci_hdm_ioremap_current(pdev, snapshot->hdm_bar,
+ snapshot->hdm_offset,
+ snapshot->hdm_size);
+ if (IS_ERR(hdm)) {
+ pci_err(pdev, "failed to map CXL HDM state for restore: %ld\n",
+ PTR_ERR(hdm));
+ return PTR_ERR(hdm);
+ }
+
+ rc = cxl_restore_hdm_state(pdev, hdm, snapshot);
+ iounmap(hdm);
+ if (rc)
+ return rc;
+
+ if (!snapshot->dvsec_ctrl_valid) {
+ pci_err(pdev, "CXL DVSEC control snapshot is invalid\n");
+ return -ENXIO;
+ }
+ rc = cxl_restore_dvsec_ctrl(pdev, snapshot->dvsec_ctrl);
+ if (rc)
+ pci_err(pdev, "failed to restore CXL DVSEC control: %d\n", rc);
+
+ return rc;
+}
+
+static void cxl_reset_save_disabled_state(struct pci_dev *pdev)
+{
+ u32 *saved_command = &pdev->saved_config_space[PCI_COMMAND / 4];
+ int rc;
+
+ rc = pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
+ if (rc)
+ pci_err(pdev,
+ "failed to disable device after CXL reset failure: %d\n",
+ pcibios_err_to_errno(rc));
+
+ /* Preserve the pre-reset snapshot if PCI state has not been restored. */
+ if (!pdev->state_saved) {
+ rc = pci_save_state(pdev);
+ if (rc)
+ pci_err(pdev,
+ "failed to save disabled state after CXL reset failure: %d\n",
+ rc);
+ }
+
+ /* Ensure the outer PCI restore cannot re-enable MSE or BME. */
+ *saved_command &= GENMASK(31, 16);
+ *saved_command |= PCI_COMMAND_INTX_DISABLE;
+}
+
+static int cxl_reset_save_restored_state(struct pci_dev *pdev, u16 command)
+{
+ int rc;
+
+ rc = pci_write_config_word(pdev, PCI_COMMAND, command);
+ if (rc) {
+ rc = pcibios_err_to_errno(rc);
+ pci_err(pdev, "failed to restore PCI command state: %d\n", rc);
+ cxl_reset_save_disabled_state(pdev);
+ return rc;
+ }
+
+ rc = pci_save_state(pdev);
+ if (rc) {
+ pci_err(pdev, "failed to save restored state after CXL reset: %d\n",
+ rc);
+ cxl_reset_save_disabled_state(pdev);
+ }
+
+ return rc;
+}
+
/*
* CXL r4.0 sec 9.7.2 defines the reset completion timeout encodings.
* Sec 9.7.3 leaves config-space access behavior undefined for 100 ms after
@@ -814,7 +1164,9 @@ static int cxl_clear_memory(struct pci_dev *pdev, int dvsec, bool initiate)
}
static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap,
- struct cxl_hdm_range_context *range_ctx)
+ struct cxl_hdm_info *snapshot,
+ struct cxl_hdm_range_context *range_ctx,
+ u16 *command)
{
int rc, rc2;
@@ -839,42 +1191,69 @@ static int __cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap,
pci_err(pdev, "failed to clear CXL Reset Memory Clear: %d\n", rc2);
rc = rc ?: rc2;
+ if (!rc) {
+ cxl_restore_pci_state_for_hdm_restore(pdev, command);
+ rc = cxl_restore_state(pdev, snapshot);
+ }
+
/* Evict lines fetched during reset before ending DMA exclusion. */
rc2 = cxl_hdm_ranges_invalidate(range_ctx);
rc = rc ?: rc2;
+ if (rc)
+ cxl_reset_save_disabled_state(pdev);
pci_dev_reset_iommu_done(pdev);
return rc;
}
-static int cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap,
- struct cxl_hdm_range_context *range_ctx)
+static int cxl_reset_execute(struct pci_dev *pdev, int dvsec, u16 cap)
{
- u16 saved_ctrl2;
+ struct cxl_hdm_info *snapshot = NULL;
+ struct cxl_hdm_range_context range_ctx;
+ u16 command, saved_ctrl2;
int rc, rc2;
+ guard(rwsem_write)(&cxl_rwsem.region);
rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, &saved_ctrl2);
if (rc)
- rc = pcibios_err_to_errno(rc);
- else if (PCI_POSSIBLE_ERROR(saved_ctrl2))
- rc = -ENODEV;
+ return pcibios_err_to_errno(rc);
+ if (PCI_POSSIBLE_ERROR(saved_ctrl2))
+ return -ENODEV;
+
+ INIT_LIST_HEAD(&range_ctx.ranges);
+
+ rc = cxl_hdm_ranges_prepare(&range_ctx, pdev);
+ if (rc) {
+ cxl_hdm_range_context_destroy(&range_ctx);
+ return rc;
+ }
+
+ rc = cxl_snapshot_hdm(pdev, &snapshot);
if (rc) {
- cxl_hdm_range_context_destroy(range_ctx);
+ cxl_hdm_range_context_destroy(&range_ctx);
return rc;
}
rc = cxl_reset_disable_cache(pdev, dvsec, cap);
if (!rc)
- rc = __cxl_reset_execute(pdev, dvsec, cap, range_ctx);
+ rc = __cxl_reset_execute(pdev, dvsec, cap, snapshot, &range_ctx,
+ &command);
/* Restore cache policy after any attempt to disable caching. */
rc2 = cxl_reset_restore_cache_policy(pdev, dvsec, saved_ctrl2);
- cxl_hdm_range_context_destroy(range_ctx);
- return rc ?: rc2;
+ kfree(snapshot);
+ cxl_hdm_range_context_destroy(&range_ctx);
+ if (rc)
+ return rc;
+ if (rc2) {
+ cxl_reset_save_disabled_state(pdev);
+ return rc2;
+ }
+
+ return cxl_reset_save_restored_state(pdev, command);
}
int cxl_reset_function(struct pci_dev *pdev, bool probe)
{
- struct cxl_hdm_range_context range_ctx;
int dvsec, rc;
u16 cap, ctrl;
@@ -917,18 +1296,5 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
if (!cpu_cache_has_invalidate_memregion())
return -ENOTTY;
- INIT_LIST_HEAD(&range_ctx.ranges);
-
- scoped_guard(rwsem_write, &cxl_rwsem.region) {
- rc = cxl_hdm_ranges_prepare(&range_ctx, pdev);
- if (rc) {
- cxl_hdm_range_context_destroy(&range_ctx);
- return rc;
- }
-
- /* cxl_reset_execute() releases the ranges on success and failure. */
- rc = cxl_reset_execute(pdev, dvsec, cap, &range_ctx);
- }
-
- return rc;
+ return cxl_reset_execute(pdev, dvsec, cap);
}
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 15/16] PCI/CXL: Expose CXL Reset as a PCI reset method
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (13 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 14/16] cxl: Restore CXL state after PCI reset Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
2026-10-01 9:22 ` [PATCH v14 16/16] PCI/CXL: Restore CXL state after CXL bus reset Srirangan Madhavan
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
Register cxl_reset with the PCI reset-method interface and place it before
FLR, which does not reset CXL.cache or CXL.mem protocol state.
Return -ENOTTY when device capabilities, function scope, cached HDM state,
or required cache synchronization do not permit a safe reset.
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 8 ++++----
drivers/pci/pci.c | 2 ++
include/linux/pci.h | 2 +-
3 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index 0acc471d0d7e..efbab341b30f 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -1264,9 +1264,9 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CAP, &cap);
if (rc)
- return pcibios_err_to_errno(rc);
+ return probe ? -ENOTTY : pcibios_err_to_errno(rc);
if (PCI_POSSIBLE_ERROR(cap))
- return -ENODEV;
+ return probe ? -ENOTTY : -ENODEV;
if (!(cap & PCI_DVSEC_CXL_CACHE_CAPABLE) ||
!(cap & PCI_DVSEC_CXL_MEM_CAPABLE) ||
!(cap & PCI_DVSEC_CXL_RST_CAPABLE) ||
@@ -1275,9 +1275,9 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL, &ctrl);
if (rc)
- return pcibios_err_to_errno(rc);
+ return probe ? -ENOTTY : pcibios_err_to_errno(rc);
if (PCI_POSSIBLE_ERROR(ctrl))
- return -ENODEV;
+ return probe ? -ENOTTY : -ENODEV;
if (!(ctrl & PCI_DVSEC_CXL_CACHE_ENABLE) ||
!(ctrl & PCI_DVSEC_CXL_MEM_ENABLE))
return -ENOTTY;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index fe611340f5ab..dc57a202c91f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -35,6 +35,7 @@
#include <linux/aer.h>
#include <linux/bitfield.h>
#include <linux/suspend.h>
+#include <cxl/cxl.h>
#include "pci.h"
DEFINE_MUTEX(pci_slot_mutex);
@@ -5148,6 +5149,7 @@ const struct pci_reset_fn_method pci_reset_fn_methods[] = {
{ },
{ pci_dev_specific_reset, .name = "device_specific" },
{ pci_dev_acpi_reset, .name = "acpi" },
+ { cxl_reset_function, .name = "cxl_reset" },
{ pcie_reset_flr, .name = "flr" },
{ pci_af_flr, .name = "af_flr" },
{ pci_pm_reset, .name = "pm" },
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7bb37fcb556d..743b57ff885a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,7 +52,7 @@
PCI_STATUS_PARITY)
/* Number of reset methods used in pci_reset_fn_methods array in pci.c */
-#define PCI_NUM_RESET_METHODS 8
+#define PCI_NUM_RESET_METHODS 9
#define PCI_RESET_PROBE true
#define PCI_RESET_DO_RESET false
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread* [PATCH v14 16/16] PCI/CXL: Restore CXL state after CXL bus reset
2026-10-01 9:22 [PATCH v14 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
` (14 preceding siblings ...)
2026-10-01 9:22 ` [PATCH v14 15/16] PCI/CXL: Expose CXL Reset as a PCI reset method Srirangan Madhavan
@ 2026-10-01 9:22 ` Srirangan Madhavan
15 siblings, 0 replies; 17+ messages in thread
From: Srirangan Madhavan @ 2026-10-01 9:22 UTC (permalink / raw)
To: Alison Schofield, Bjorn Helgaas, Dave Jiang, Davidlohr Bueso,
Ira Weiny, Jonathan Cameron, Vishal Verma, linux-cxl, linux-pci,
linux-kernel
Cc: Alex Williamson, vsethi, alwilliamson,
Sai Yashwanth Reddy Kancherla, Vishal Aslot, Manish Honap,
Jiandi An, Richard Cheng, linux-tegra, Srirangan Madhavan
CXL bus reset can clear HDM decoder programming and CXL Device DVSEC
control state. Restore the cached state after a successful cxl_bus reset
while IOMMU exclusion remains active.
Restore PCI configuration first so HDM MMIO is accessible, and preserve a
disabled state if restoration fails.
Tested-by: Richard Cheng <icheng@nvidia.com>
Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
drivers/cxl/core/resource.c | 23 +++++++++++++++++++++--
drivers/pci/pci.c | 8 ++++++++
include/cxl/cxl.h | 17 +++++++++++++++++
3 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
index efbab341b30f..3422139ae3ab 100644
--- a/drivers/cxl/core/resource.c
+++ b/drivers/cxl/core/resource.c
@@ -625,12 +625,12 @@ static int cxl_restore_hdm_decoder(struct pci_dev *pdev, void __iomem *hdm,
return 0;
}
-static int cxl_snapshot_hdm(struct pci_dev *pdev,
- struct cxl_hdm_info **snapshot)
+int cxl_snapshot_hdm(struct pci_dev *pdev, struct cxl_hdm_info **snapshot)
{
struct cxl_hdm_info *info;
size_t size;
+ device_lock_assert(&pdev->dev);
guard(rwsem_read)(&cxl_rwsem.dpa);
info = pdev->hdm;
if (!info)
@@ -798,6 +798,25 @@ static int cxl_reset_save_restored_state(struct pci_dev *pdev, u16 command)
return rc;
}
+int cxl_restore_state_after_pci_reset(struct pci_dev *pdev,
+ struct cxl_hdm_info *snapshot)
+{
+ u16 command;
+ int rc;
+
+ device_lock_assert(&pdev->dev);
+ guard(rwsem_write)(&cxl_rwsem.region);
+
+ cxl_restore_pci_state_for_hdm_restore(pdev, &command);
+ rc = cxl_restore_state(pdev, snapshot);
+ if (rc) {
+ cxl_reset_save_disabled_state(pdev);
+ return rc;
+ }
+
+ return cxl_reset_save_restored_state(pdev, command);
+}
+
/*
* CXL r4.0 sec 9.7.2 defines the reset completion timeout encodings.
* Sec 9.7.3 leaves config-space access behavior undefined for 100 ms after
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index dc57a202c91f..6928c99aa785 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5015,6 +5015,7 @@ static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
{
+ struct cxl_hdm_info *snapshot __free(kfree) = NULL;
struct pci_dev *bridge;
u16 dvsec, reg, val;
int rc;
@@ -5037,6 +5038,10 @@ static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
if (rc)
return -ENOTTY;
+ rc = cxl_snapshot_hdm(dev, &snapshot);
+ if (rc && rc != -ENXIO)
+ return rc;
+
rc = pci_dev_reset_iommu_prepare(dev);
if (rc) {
pci_err(dev, "failed to stop IOMMU for a PCI reset: %d\n", rc);
@@ -5057,6 +5062,9 @@ static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
pci_write_config_word(bridge, dvsec + PCI_DVSEC_CXL_PORT_CTL,
reg);
+ if (!rc && snapshot)
+ rc = cxl_restore_state_after_pci_reset(dev, snapshot);
+
pci_dev_reset_iommu_done(dev);
return rc;
}
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 9904eaed5af1..b83cfaed618f 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -207,6 +207,9 @@ struct cxl_register_map {
#ifdef CONFIG_CXL_RESET
void pci_cxl_hdm_cache_init(struct pci_dev *pdev);
void pci_cxl_hdm_cache_release(struct pci_dev *pdev);
+int cxl_snapshot_hdm(struct pci_dev *pdev, struct cxl_hdm_info **snapshot);
+int cxl_restore_state_after_pci_reset(struct pci_dev *pdev,
+ struct cxl_hdm_info *snapshot);
int cxl_reset_function(struct pci_dev *pdev, bool probe);
#else
static inline void pci_cxl_hdm_cache_init(struct pci_dev *pdev)
@@ -217,6 +220,20 @@ static inline void pci_cxl_hdm_cache_release(struct pci_dev *pdev)
{
}
+static inline int cxl_snapshot_hdm(struct pci_dev *pdev,
+ struct cxl_hdm_info **snapshot)
+{
+ *snapshot = NULL;
+ return -ENXIO;
+}
+
+static inline int
+cxl_restore_state_after_pci_reset(struct pci_dev *pdev,
+ struct cxl_hdm_info *snapshot)
+{
+ return 0;
+}
+
static inline int cxl_reset_function(struct pci_dev *pdev, bool probe)
{
return -ENOTTY;
--
2.43.0
^ permalink raw reply [flat|nested] 17+ messages in thread