[PATCH v1 01/14] cxl/core: Return endpoint decoder information from region search

[Anisa Su <anisa.su887@gmail.com>]

From: Ira Weiny <iweiny@kernel.org>

cxl_dpa_to_region() finds the region from a <DPA, device> tuple.
The search involves finding the device endpoint decoder as well.

Dynamic capacity extent processing uses the endpoint decoder HPA
information to calculate the HPA offset.  In addition, well behaved
extents should be contained within an endpoint decoder.

Return the endpoint decoder found to be used in subsequent DCD code.

Signed-off-by: Ira Weiny <iweiny@kernel.org>
Co-developed-by: Anisa Su <anisa.su@samsung.com>
Signed-off-by: Anisa Su <anisa.su@samsung.com>
Tested-by: Wonjae Lee <wj28.lee@samsung.com>
Tested-by: Junhee Park <jh9934.park@samsung.com>
Tested-by: Heesoo Kim <habil.kim@samsung.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Fan Ni <nifan.cxl@gmail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/core/core.h   |  8 ++++++--
 drivers/cxl/core/mbox.c   |  2 +-
 drivers/cxl/core/memdev.c |  4 ++--
 drivers/cxl/core/region.c | 12 +++++++++++-
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 79918fde1575..8a81be004d00 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -47,7 +47,8 @@ int cxl_decoder_detach(struct cxl_region *cxlr,
 int cxl_region_init(void);
 void cxl_region_exit(void);
 int cxl_get_poison_by_endpoint(struct cxl_port *port);
-struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa);
+struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa,
+				     struct cxl_endpoint_decoder **cxled);
 u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 		   u64 dpa);
 int devm_cxl_add_dax_region(struct cxl_region *cxlr);
@@ -61,8 +62,11 @@ static inline u64 cxl_dpa_to_hpa(struct cxl_region *cxlr,
 	return ULLONG_MAX;
 }
 static inline
-struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa)
+struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa,
+				     struct cxl_endpoint_decoder **cxled)
 {
+	if (cxled)
+		*cxled = NULL;
 	return NULL;
 }
 static inline int cxl_get_poison_by_endpoint(struct cxl_port *port)
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 39485b6bcb97..13a68f5cef69 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -966,7 +966,7 @@ void cxl_event_trace_record(struct cxl_memdev *cxlmd,
 		guard(rwsem_read)(&cxl_rwsem.dpa);
 
 		dpa = le64_to_cpu(evt->media_hdr.phys_addr) & CXL_DPA_MASK;
-		cxlr = cxl_dpa_to_region(cxlmd, dpa);
+		cxlr = cxl_dpa_to_region(cxlmd, dpa, NULL);
 		if (cxlr) {
 			u64 cache_size = cxlr->params.cache_size;
 
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 787988e92965..81f1e0441787 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -309,7 +309,7 @@ int cxl_inject_poison_locked(struct cxl_memdev *cxlmd, u64 dpa)
 	if (rc)
 		return rc;
 
-	cxlr = cxl_dpa_to_region(cxlmd, dpa);
+	cxlr = cxl_dpa_to_region(cxlmd, dpa, NULL);
 	if (cxlr)
 		dev_warn_once(cxl_mbox->host,
 			      "poison inject dpa:%#llx region: %s\n", dpa,
@@ -378,7 +378,7 @@ int cxl_clear_poison_locked(struct cxl_memdev *cxlmd, u64 dpa)
 	if (rc)
 		return rc;
 
-	cxlr = cxl_dpa_to_region(cxlmd, dpa);
+	cxlr = cxl_dpa_to_region(cxlmd, dpa, NULL);
 	if (cxlr)
 		dev_warn_once(cxl_mbox->host,
 			      "poison clear dpa:%#llx region: %s\n", dpa,
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index a048bd5c06cb..f4a9839c73d2 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3045,6 +3045,7 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port)
 struct cxl_dpa_to_region_context {
 	struct cxl_region *cxlr;
 	u64 dpa;
+	struct cxl_endpoint_decoder *cxled;
 };
 
 static int __cxl_dpa_to_region(struct device *dev, void *arg)
@@ -3078,15 +3079,21 @@ static int __cxl_dpa_to_region(struct device *dev, void *arg)
 			dev_name(dev));
 
 	ctx->cxlr = cxlr;
+	ctx->cxled = cxled;
 
 	return 1;
 }
 
-struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa)
+/* @cxled receives the decoder mapping @dpa, if any, even with no region. */
+struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa,
+				     struct cxl_endpoint_decoder **cxled)
 {
 	struct cxl_dpa_to_region_context ctx;
 	struct cxl_port *port = cxlmd->endpoint;
 
+	if (cxled)
+		*cxled = NULL;
+
 	if (!cxlmd->dev.driver)
 		return NULL;
 
@@ -3096,6 +3103,9 @@ struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa)
 	if (cxl_num_decoders_committed(port))
 		device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region);
 
+	if (cxled)
+		*cxled = ctx.cxled;
+
 	return ctx.cxlr;
 }
 
-- 
2.43.0