Re: [PATCH 3/4 v3] ACPI: extlog: Trace CPER PCI Express Error Section

[Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>]

On 6/3/25 8:54 AM, Fabio M. De Francesco wrote:
> I/O Machine Check Architecture events may signal failing PCIe components
> or links. The AER event contains details on what was happening on the wire
> when the error was signaled.
>
> Trace the CPER PCIe Error section (UEFI v2.10, Appendix N.2.7) reported
> by the I/O MCA.
>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
> ---
>   drivers/acpi/Kconfig       |  1 +
>   drivers/acpi/acpi_extlog.c | 32 ++++++++++++++++++++++++++++++++
>   drivers/pci/pcie/aer.c     |  2 +-
>   include/linux/aer.h        |  8 ++++++--
>   4 files changed, 40 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 7bc40c2735ac0..2bbd9e4868ad7 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -493,6 +493,7 @@ config ACPI_EXTLOG
>   	tristate "Extended Error Log support"
>   	depends on X86_MCE && X86_LOCAL_APIC && EDAC
>   	select UEFI_CPER
> +	select ACPI_APEI_PCIEAER
>   	help
>   	  Certain usages such as Predictive Failure Analysis (PFA) require
>   	  more information about the error than what can be described in
> diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
> index 47d11cb5c9120..b2928ff297eda 100644
> --- a/drivers/acpi/acpi_extlog.c
> +++ b/drivers/acpi/acpi_extlog.c
> @@ -132,6 +132,34 @@ static int print_extlog_rcd(const char *pfx,
>   	return 1;
>   }
>   
> +static void extlog_print_pcie(struct cper_sec_pcie *pcie_err,
> +			      int severity)
> +{
> +	struct aer_capability_regs *aer;
> +	struct pci_dev *pdev;
> +	unsigned int devfn;
> +	unsigned int bus;
> +	int aer_severity;
> +	int domain;
> +
> +	if (!(pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID ||
> +	      pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO))
> +		return;
> +
> +	aer_severity = cper_severity_to_aer(severity);
> +	aer = (struct aer_capability_regs *)pcie_err->aer_info;
> +	domain = pcie_err->device_id.segment;
> +	bus = pcie_err->device_id.bus;
> +	devfn = PCI_DEVFN(pcie_err->device_id.device,
> +			  pcie_err->device_id.function);
> +	pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
> +	if (!pdev)
> +		return;
> +
> +	pci_print_aer(KERN_DEBUG, pdev, aer_severity, aer);
> +	pci_dev_put(pdev);
> +}
> +
>   static int extlog_print(struct notifier_block *nb, unsigned long val,
>   			void *data)
>   {
> @@ -183,6 +211,10 @@ static int extlog_print(struct notifier_block *nb, unsigned long val,
>   			if (gdata->error_data_length >= sizeof(*mem))
>   				trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
>   						       (u8)gdata->error_severity);
> +		} else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
> +			struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
> +
> +			extlog_print_pcie(pcie_err, gdata->error_severity);
>   		} else {
>   			void *err = acpi_hest_get_payload(gdata);
>   
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index d0ebf7c15afa9..627fcf4346983 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -801,7 +801,7 @@ void pci_print_aer(char *level, struct pci_dev *dev, int aer_severity,
>   	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
>   			aer_severity, tlp_header_valid, &aer->header_log);
>   }
> -EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
> +EXPORT_SYMBOL_GPL(pci_print_aer);
>   
>   /**
>    * add_error_device - list device to be handled
> diff --git a/include/linux/aer.h b/include/linux/aer.h
> index 45d0fb2e2e759..6ce433cee4625 100644
> --- a/include/linux/aer.h
> +++ b/include/linux/aer.h
> @@ -56,16 +56,20 @@ struct aer_capability_regs {
>   #if defined(CONFIG_PCIEAER)
>   int pci_aer_clear_nonfatal_status(struct pci_dev *dev);
>   int pcie_aer_is_native(struct pci_dev *dev);
> +void pci_print_aer(char *level, struct pci_dev *dev, int aer_severity,
> +		   struct aer_capability_regs *aer);
>   #else
>   static inline int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
>   {
>   	return -EINVAL;
>   }
>   static inline int pcie_aer_is_native(struct pci_dev *dev) { return 0; }
> +static inline void pci_print_aer(char *level, struct pci_dev *dev,
> +				 int aer_severity,
> +				 struct aer_capability_regs *aer)
> +{ }

This also needs rebase. With the patches queued for v6.16, you may not
need to pass level any more.

>   #endif
>   
> -void pci_print_aer(char *level, struct pci_dev *dev, int aer_severity,
> -		   struct aer_capability_regs *aer);
>   int cper_severity_to_aer(int cper_severity);
>   void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
>   		       int severity, struct aer_capability_regs *aer_regs);

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer