[RESEND v13 15/25] CXL/PCI: Introduce PCI_ERS_RESULT_PANIC

Terry Bowman
2025-11-04T17:06:03Z

The CXL driver's error handling for uncorrectable errors (UCE) will be
updated in the future. A required change is for the error handlers to
to force a system panic when a UCE is detected.

Introduce PCI_ERS_RESULT_PANIC as a 'enum pci_ers_result' type. This will
be used by CXL UCE fatal and non-fatal recovery in future patches. Update
PCIe recovery documentation with details of PCI_ERS_RESULT_PANIC.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>

---

Changes in v12->v13:
- Add Dave Jiang's, Jonathan's, Ben's review-by
- Typo fix (Ben)

Changes v11 -> v12:
- Documentation requested (Lukas)
---
Documentation/PCI/pci-error-recovery.rst | 6 ++++++
include/linux/pci.h | 3 +++
2 files changed, 9 insertions(+)

diff --git a/Documentation/PCI/pci-error-recovery.rst b/Documentation/PCI/pci-error-recovery.rst
index 5df481ac6193..83505a585116 100644
--- a/Documentation/PCI/pci-error-recovery.rst
+++ b/Documentation/PCI/pci-error-recovery.rst
@@ -102,6 +102,8 @@ Possible return values are::
PCI_ERS_RESULT_NEED_RESET, /* Device driver wants slot to be reset. */
PCI_ERS_RESULT_DISCONNECT, /* Device has completely failed, is unrecoverable */
PCI_ERS_RESULT_RECOVERED, /* Device driver is fully recovered and operational */
+ PCI_ERS_RESULT_NO_AER_DRIVER, /* No AER capabilities registered for the driver */
+ PCI_ERS_RESULT_PANIC, /* System is unstable, panic. Is CXL specific */
};

A driver does not have to implement all of these callbacks; however,
@@ -116,6 +118,10 @@ The actual steps taken by a platform to recover from a PCI error
event will be platform-dependent, but will follow the general
sequence described below.

+PCI_ERS_RESULT_PANIC is currently unique to CXL and handled in CXL
+cxl_do_recovery(). The PCI pcie_do_recovery() routine does not report or
+handle PCI_ERS_RESULT_PANIC.
+
STEP 0: Error Event
-------------------
A PCI bus error is detected by the PCI hardware. On powerpc, the slot
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5c4759078d2f..cffa5535f28d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -890,6 +890,9 @@ enum pci_ers_result {

/* No AER capabilities registered for the driver */
PCI_ERS_RESULT_NO_AER_DRIVER = (__force pci_ers_result_t) 6,
+
+ /* System is unstable, panic. Is CXL specific */
+ PCI_ERS_RESULT_PANIC = (__force pci_ers_result_t) 7,
};

/* PCI bus error event callbacks */
--
2.34.1