From: Srirangan Madhavan <smadhavan@nvidia.com>
To: Alison Schofield <alison.schofield@intel.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Dave Jiang <dave.jiang@intel.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Ira Weiny <ira.weiny@intel.com>,
Jonathan Cameron <jic23@kernel.org>,
Vishal Verma <vishal.l.verma@intel.com>,
linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
vsethi@nvidia.com, alwilliamson@nvidia.com,
Sai Yashwanth Reddy Kancherla <skancherla@nvidia.com>,
Vishal Aslot <vaslot@nvidia.com>,
Manish Honap <mhonap@nvidia.com>, Jiandi An <jan@nvidia.com>,
Richard Cheng <icheng@nvidia.com>,
linux-tegra@vger.kernel.org,
Srirangan Madhavan <smadhavan@nvidia.com>
Subject: [PATCH v15 14/16] PCI/CXL: Expose CXL Reset as a PCI reset method
Date: Sun, 11 Oct 2026 02:14:20 +0000 [thread overview]
Message-ID: <20261011021422.3428136-15-smadhavan@nvidia.com> (raw)
In-Reply-To: <20261011021422.3428136-1-smadhavan@nvidia.com>
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/pci/cxl.c | 12 +++++++++---
drivers/pci/pci.c | 1 +
include/linux/pci.h | 2 +-
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/cxl.c b/drivers/pci/cxl.c
index 4c6b712ed4fa..7a225e215ca5 100644
--- a/drivers/pci/cxl.c
+++ b/drivers/pci/cxl.c
@@ -642,7 +642,7 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
rc = cxl_pci_device_dvsec(pdev, &dvsec, &cap);
if (rc)
- return rc;
+ return probe ? -ENOTTY : rc;
if (!(cap & PCI_DVSEC_CXL_CACHE_CAPABLE) ||
!(cap & PCI_DVSEC_CXL_MEM_CAPABLE) ||
!(cap & PCI_DVSEC_CXL_RST_CAPABLE) ||
@@ -651,9 +651,9 @@ 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;
@@ -675,5 +675,11 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe)
if (!cpu_cache_has_invalidate_memregion())
return -ENOTTY;
+ /* Raw reset callers may not have saved the PCI state needed for restore. */
+ if (!pdev->state_saved) {
+ pci_err(pdev, "CXL reset requires saved PCI state\n");
+ return -EINVAL;
+ }
+
return cxl_reset_execute(pdev, dvsec, cap);
}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index fe611340f5ab..b58a6a613311 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5148,6 +5148,7 @@ 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
next prev parent reply other threads:[~2026-10-11 2:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-11 2:14 [PATCH v15 00/16] PCI/CXL: Add CXL reset support for Type 2 devices Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 01/16] cxl: Drop stale decoder interleave limit comment Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 02/16] cxl: Share CXL port upstream PCI device lookup Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 03/16] cxl: Move decoder declarations to shared header Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 04/16] cxl: Embed decoder configuration in a standalone structure Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 05/16] cxl: Introduce endpoint HDM decoder settings Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 06/16] cxl: Move HDM decoder helpers to built-in code Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 07/16] cxl: Share HDM decoder register unpacking Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 08/16] cxl: Refresh cached PCI HDM decoder settings Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 09/16] PCI/CXL: Cache endpoint HDM state during PCI enumeration Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 10/16] PCI/CXL: Add CXL Device Reset sequencing Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 11/16] cxl: Validate and synchronize HDM ranges around reset Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 12/16] PCI/CXL: Reject reset with unsafe function scope Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 13/16] PCI/CXL: Restore CXL state after PCI reset Srirangan Madhavan
2026-10-11 2:14 ` Srirangan Madhavan [this message]
2026-10-11 2:14 ` [PATCH v15 15/16] PCI/CXL: Restore CXL state after CXL bus reset Srirangan Madhavan
2026-10-11 2:14 ` [PATCH v15 16/16] tools/testing/cxl: Add HDM decoder range checks Srirangan Madhavan
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