Re: [PATCH v8 02/16] PCI/AER: Modify AER driver logging to report CXL or PCIe bus error type

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Mar 26, 2025 at 08:47:03PM -0500, Terry Bowman wrote:
> The AER service driver and aer_event tracing currently log 'PCIe Bus Type'
> for all errors. Update the driver and aer_event tracing to log 'CXL Bus
> Type' for CXL device errors.
> 
> This requires the AER can identify and distinguish between PCIe errors and
> CXL errors.
> 
> Introduce boolean 'is_cxl' to 'struct aer_err_info'. Add assignment in
> aer_get_device_error_info() and pci_print_aer().
> 
> Update the aer_event trace routine to accept a bus type string parameter.

> +++ b/drivers/pci/pci.h
> @@ -533,6 +533,7 @@ static inline bool pci_dev_test_and_set_removed(struct pci_dev *dev)
>  struct aer_err_info {
>  	struct pci_dev *dev[AER_MAX_MULTI_ERR_DEVICES];
>  	int error_dev_num;
> +	bool is_cxl;
>  
>  	unsigned int id:16;
>  
> @@ -549,6 +550,11 @@ struct aer_err_info {
>  	struct pcie_tlp_log tlp;	/* TLP Header */
>  };
>  
> +static inline const char *aer_err_bus(struct aer_err_info *info)
> +{
> +	return info->is_cxl ? "CXL" : "PCIe";

I don't really see the point in adding struct aer_err_info.is_cxl.
Every place where we call aer_err_bus() to look at it, we also have
the struct pci_dev pointer, so we could just as easily use
pcie_is_cxl() here.

> +}
> +
>  int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
>  void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
>  
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 508474e17183..83f2069f111e 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -694,13 +694,14 @@ static void __aer_print_error(struct pci_dev *dev,
>  
>  void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  {
> +	const char *bus_type = aer_err_bus(info);
>  	int layer, agent;
>  	int id = pci_dev_id(dev);
>  	const char *level;
>  
>  	if (!info->status) {
> -		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
> -			aer_error_severity_string[info->severity]);
> +		pci_err(dev, "%s Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
> +			bus_type, aer_error_severity_string[info->severity]);
>  		goto out;
>  	}
>  
> @@ -709,8 +710,8 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  
>  	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
>  
> -	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
> -		   aer_error_severity_string[info->severity],
> +	pci_printk(level, dev, "%s Bus Error: severity=%s, type=%s, (%s)\n",
> +		   bus_type, aer_error_severity_string[info->severity],
>  		   aer_error_layer[layer], aer_agent_string[agent]);
>  
>  	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
> @@ -725,7 +726,7 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  	if (info->id && info->error_dev_num > 1 && info->id == id)
>  		pci_err(dev, "  Error of this Agent is reported first\n");
>  
> -	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
> +	trace_aer_event(dev_name(&dev->dev), bus_type, (info->status & ~info->mask),
>  			info->severity, info->tlp_header_valid, &info->tlp);
>  }
>  
> @@ -759,6 +760,7 @@ EXPORT_SYMBOL_GPL(cper_severity_to_aer);
>  void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  		   struct aer_capability_regs *aer)
>  {
> +	const char *bus_type;
>  	int layer, agent, tlp_header_valid = 0;
>  	u32 status, mask;
>  	struct aer_err_info info;
> @@ -780,6 +782,9 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  	info.status = status;
>  	info.mask = mask;
>  	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
> +	info.is_cxl = pcie_is_cxl(dev);
> +
> +	bus_type = aer_err_bus(&info);
>  
>  	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
>  	__aer_print_error(dev, &info);
> @@ -793,7 +798,7 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  	if (tlp_header_valid)
>  		pcie_print_tlp_log(dev, &aer->header_log, dev_fmt("  "));
>  
> -	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
> +	trace_aer_event(dev_name(&dev->dev), bus_type, (status & ~mask),
>  			aer_severity, tlp_header_valid, &aer->header_log);
>  }
>  EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
> @@ -1211,6 +1216,7 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
>  	/* Must reset in this function */
>  	info->status = 0;
>  	info->tlp_header_valid = 0;
> +	info->is_cxl = pcie_is_cxl(dev);
>  
>  	/* The device might not support AER */
>  	if (!aer)
> diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
> index e5f7ee0864e7..1bf8e7050ba8 100644
> --- a/include/ras/ras_event.h
> +++ b/include/ras/ras_event.h
> @@ -297,15 +297,17 @@ TRACE_EVENT(non_standard_event,
>  
>  TRACE_EVENT(aer_event,
>  	TP_PROTO(const char *dev_name,
> +		 const char *bus_type,
>  		 const u32 status,
>  		 const u8 severity,
>  		 const u8 tlp_header_valid,
>  		 struct pcie_tlp_log *tlp),
>  
> -	TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp),
> +	TP_ARGS(dev_name, bus_type, status, severity, tlp_header_valid, tlp),
>  
>  	TP_STRUCT__entry(
>  		__string(	dev_name,	dev_name	)
> +		__string(	bus_type,	bus_type	)
>  		__field(	u32,		status		)
>  		__field(	u8,		severity	)
>  		__field(	u8, 		tlp_header_valid)
> @@ -314,6 +316,7 @@ TRACE_EVENT(aer_event,
>  
>  	TP_fast_assign(
>  		__assign_str(dev_name);
> +		__assign_str(bus_type);
>  		__entry->status		= status;
>  		__entry->severity	= severity;
>  		__entry->tlp_header_valid = tlp_header_valid;
> @@ -325,8 +328,8 @@ TRACE_EVENT(aer_event,
>  		}
>  	),
>  
> -	TP_printk("%s PCIe Bus Error: severity=%s, %s, TLP Header=%s\n",
> -		__get_str(dev_name),
> +	TP_printk("%s %s Bus Error: severity=%s, %s, TLP Header=%s\n",
> +		__get_str(dev_name), __get_str(bus_type),
>  		__entry->severity == AER_CORRECTABLE ? "Corrected" :
>  			__entry->severity == AER_FATAL ?
>  			"Fatal" : "Uncorrected, non-fatal",
> -- 
> 2.34.1
>