[PATCH v15 3/9] PCI/ERR: Introduce PCI_ERS_RESULT_PANIC

[Terry Bowman <terry.bowman@amd.com>]

The CXL driver's uncorrectable (UCE) protocol error handling will be updated
in the future. One required change is for the error handlers 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>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>

---

Changes in v14 -> v15:
- None

Changes in v13 -> v14:
- Add review-by for Dan
- Update Title prefix (Bjorn)
- Removed merge_result. Only logging error for device reporting the
  error (Dan)

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 | 2 ++
 include/linux/pci.h                      | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/Documentation/PCI/pci-error-recovery.rst b/Documentation/PCI/pci-error-recovery.rst
index 43bc4e3665b4..82ee2c8c0450 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,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f8e8b3df794d..ee05d5925b13 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -921,6 +921,9 @@ 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