[PATCH v12 16/25] CXL/PCI: Introduce PCI_ERS_RESULT_PANIC

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

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>

---

Changes v11 -> v12:
- Documentation requested by (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 42e1e78353f3..f823a6c1fb23 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_recdovery(). 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 53a45e92c635..bc3a7b6d0f94 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -889,6 +889,9 @@ 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