[PATCH] powerpc/eeh: parse AER registers

[Mahesh J Salgaonkar]

On 2025-07-03 09:15:04 Thu, Ganesh Goudar wrote:
> parse AER uncorrectable and correctable error status
> registers to print error type and severity.
> 
> output looks like
> EEH:AER Uncorrectable Error
> EEH:AER Error Type: Data Link Protocol Error [Fatal]

Thanks for working on this. But how do we know which PHB this error is
reported on ? Can we have PHB details as prefix in the error message ?

Also, can we have Error message format something like below ?

0000:50:00.0: PCIe Bus Error: severity=Uncorrected (Fatal), type=Transaction Layer, id=0500(Requester ID)

Thanks,
-Mahesh.

> 
> Signed-off-by: Ganesh Goudar <ganeshgr at linux.ibm.com>
> ---
>  arch/powerpc/kernel/eeh.c | 84 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 83 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
> index 83fe99861eb1..03e1e2eeb679 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 +203,43 @@ 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 && !cor_status)
> +		return;
> +
> +	if (uncor_status) {
> +		pr_err("EEH:AER Uncorrectable Error\n");
> +		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 Error Type: %s [%s]\n", error_type,
> +				       (uncor_severity & (1 << i)) ? "Fatal" : "Non-Fatal");
> +			}
> +		}
> +	}
> +
> +	if (cor_status) {
> +		pr_err("EEH:AER Correctable Error\n");
> +		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 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 +317,11 @@ 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");
>  
> -- 
> 2.48.1
> 
> 

-- 
Mahesh J Salgaonkar