[PATCH v2] powerpc/eeh: parse AER registers

parse AER uncorrectable and correctable error status
registers to print error type and severity.

output looks like
EEH:AER severity=Uncorrected (Fatal), Error Type: Data Link Protocol Error

Signed-off-by: Ganesh Goudar <redacted>
---
v2:
* Remove unnecessary checks.
* Change the error message format.
---
  arch/powerpc/kernel/eeh.c | 81 ++++++++++++++++++++++++++++++++++++++-
  1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 83fe99861eb1..cd083e59d6b3 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -139,6 +139,49 @@ struct eeh_stats {
  
  static struct eeh_stats eeh_stats;
  
+static const char * const aer_uncor_errors[] = {
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Data Link Protocol",
+	"Surprise Down",
+	"Poisoned TLP",
+	"Flow Control Protocol",
+	"Completion Timeout",
+	"Completer Abort",
+	"Unexpected Completion",
+	"Receiver Overflow",
+	"Malformed TLP",
+	"ECRC Error",
+	"Unsupported Request",
+	"ACS Violation",
+	"Uncorrectable Internal Error",
+	"MC Blocked TLP",
+	"AtomicOp Egress Blocked",
+	"TLPPrefix Blocked",
+	"Poisoned TLP Egress Blocked"
+};
+
+static const char * const aer_cor_errors[] = {
+	"Receiver Error",
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Bad TLP",
+	"Bad DLLP",
+	"Replay Num Rollover",
+	"Undefined",
+	"Undefined",
+	"Undefined",
+	"Replay Timer Timeout",
+	"Advisory Non-Fatal Error",
+	"Corrected Internal Error",
+	"Header Log Overflow",
+};
+
  static int __init eeh_setup(char *str)
  {
  	if (!strcmp(str, "off"))

@@ -160,6 +203,40 @@ void eeh_show_enabled(void)
  		pr_info("EEH: No capable adapters found: recovery disabled.\n");
  }
  
+static void eeh_parse_aer_registers(struct eeh_dev *edev, int cap)
+{
+	int i;
+	const char *error_type;
+	u32 uncor_status, uncor_severity, cor_status;
+
+	eeh_ops->read_config(edev, cap + PCI_ERR_UNCOR_STATUS, 4, &uncor_status);
+	eeh_ops->read_config(edev, cap + PCI_ERR_UNCOR_SEVER, 4, &uncor_severity);
+	eeh_ops->read_config(edev, cap + PCI_ERR_COR_STATUS, 4, &cor_status);
+
+	if (uncor_status) {
+		for (i = 0; i < ARRAY_SIZE(aer_uncor_errors); i++) {
+			if (uncor_status & (1 << i)) {
+				error_type = (i < ARRAY_SIZE(aer_uncor_errors))
+					     ? aer_uncor_errors[i] : "Unknown";
+				pr_err("EEH:AER severity=Uncorrected (%s), Error type: %s\n",
+				       (uncor_severity & (1 << i)) ?
+				       "Fatal" : "Non-Fatal", error_type);
+			}
+		}
+	}
+
+	if (cor_status) {
+		for (i = 0; i < ARRAY_SIZE(aer_cor_errors); i++) {
+			if (cor_status & (1 << i)) {
+				error_type = (i < ARRAY_SIZE(aer_cor_errors))
+					      ? aer_cor_errors[i] : "Unknown";
+				pr_err("EEH:AER severity=Correctable, Error Type: %s\n",
+				       error_type);
+			}
+		}
+	}
+}
+

  /*
   * This routine captures assorted PCI configuration space data
   * for the indicated PCI device, and puts them into a buffer

@@ -237,9 +314,11 @@ static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len)
  		pr_warn("%s\n", buffer);
  	}
  
-	/* If AER capable, dump it */
+	/* If AER capable, parse and dump it */
  	cap = edev->aer_cap;
  	if (cap) {
+		eeh_parse_aer_registers(edev, cap);
+
  		n += scnprintf(buf+n, len-n, "pci-e AER:\n");
  		pr_warn("EEH: PCI-E AER capability register set follows:\n");