PCI/DPC: Log Error Source ID only when valid

DPC Error Source ID is only valid when the DPC Trigger Reason indicates
that DPC was triggered due to reception of an ERR_NONFATAL or ERR_FATAL
Message (PCIe r6.0, sec 7.9.14.5).

When DPC was triggered by ERR_NONFATAL (PCI_EXP_DPC_STATUS_TRIGGER_RSN_NFE)
or ERR_FATAL (PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE) from a downstream device,
log the Error Source ID (decoded into domain/bus/device/function).  Don't
print the source otherwise, since it's not valid.

For DPC trigger due to reception of ERR_NONFATAL or ERR_FATAL, the dmesg
logging changes:

  - pci 0000:00:01.0: DPC: containment event, status:0x000d source:0x0200
  - pci 0000:00:01.0: DPC: ERR_FATAL detected
  + pci 0000:00:01.0: DPC: containment event, status:0x000d, ERR_FATAL received from 0000:02:00.0

and when DPC triggered for other reasons, where DPC Error Source ID is
undefined, e.g., unmasked uncorrectable error:

  - pci 0000:00:01.0: DPC: containment event, status:0x0009 source:0x0200
  - pci 0000:00:01.0: DPC: unmasked uncorrectable error detected
  + pci 0000:00:01.0: DPC: containment event, status:0x0009: unmasked uncorrectable error detected

Previously the "containment event" message was at KERN_INFO and the
"%s detected" message was at KERN_WARNING.  Now the single message is at
KERN_WARNING.

Fixes: 26e515713342 ("PCI: Add Downstream Port Containment driver")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-3-helgaas@kernel.org

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 3daaf61c79c9fb31723cc46f0bc2786b08de849a..9d85f1b3b761125219cef99973fa1de4746ad052 100644 (file)
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -261,37 +261,45 @@ void dpc_process_error(struct pci_dev *pdev)
        struct aer_err_info info = {};
 
        pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
-       pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source);
-
-       pci_info(pdev, "containment event, status:%#06x source:%#06x\n",
-                status, source);
 
        reason = status & PCI_EXP_DPC_STATUS_TRIGGER_RSN;
-       ext_reason = status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT;
-       pci_warn(pdev, "%s detected\n",
-                (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_UNCOR) ?
-                "unmasked uncorrectable error" :
-                (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_NFE) ?
-                "ERR_NONFATAL" :
-                (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE) ?
-                "ERR_FATAL" :
-                (ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_RP_PIO) ?
-                "RP PIO error" :
-                (ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_SW_TRIGGER) ?
-                "software trigger" :
-                "reserved error");
-
-       /* show RP PIO error detail information */
-       if (pdev->dpc_rp_extensions &&
-           reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_IN_EXT &&
-           ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_RP_PIO)
-               dpc_process_rp_pio_error(pdev);
-       else if (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_UNCOR &&
-                dpc_get_aer_uncorrect_severity(pdev, &info) &&
-                aer_get_device_error_info(pdev, &info)) {
-               aer_print_error(pdev, &info);
-               pci_aer_clear_nonfatal_status(pdev);
-               pci_aer_clear_fatal_status(pdev);
+
+       switch (reason) {
+       case PCI_EXP_DPC_STATUS_TRIGGER_RSN_UNCOR:
+               pci_warn(pdev, "containment event, status:%#06x: unmasked uncorrectable error detected\n",
+                        status);
+               if (dpc_get_aer_uncorrect_severity(pdev, &info) &&
+                   aer_get_device_error_info(pdev, &info)) {
+                       aer_print_error(pdev, &info);
+                       pci_aer_clear_nonfatal_status(pdev);
+                       pci_aer_clear_fatal_status(pdev);
+               }
+               break;
+       case PCI_EXP_DPC_STATUS_TRIGGER_RSN_NFE:
+       case PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE:
+               pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID,
+                                    &source);
+               pci_warn(pdev, "containment event, status:%#06x, %s received from %04x:%02x:%02x.%d\n",
+                        status,
+                        (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE) ?
+                               "ERR_FATAL" : "ERR_NONFATAL",
+                        pci_domain_nr(pdev->bus), PCI_BUS_NUM(source),
+                        PCI_SLOT(source), PCI_FUNC(source));
+               break;
+       case PCI_EXP_DPC_STATUS_TRIGGER_RSN_IN_EXT:
+               ext_reason = status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT;
+               pci_warn(pdev, "containment event, status:%#06x: %s detected\n",
+                        status,
+                        (ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_RP_PIO) ?
+                        "RP PIO error" :
+                        (ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_SW_TRIGGER) ?
+                        "software trigger" :
+                        "reserved error");
+               /* show RP PIO error detail information */
+               if (ext_reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_RP_PIO &&
+                   pdev->dpc_rp_extensions)
+                       dpc_process_rp_pio_error(pdev);
+               break;
        }
 }