Re: [PATCH v7 04/17] PCI/AER: Modify AER driver logging to report CXL or PCIe bus error type

Bowman, Terry
2025-02-12T19:15:08Z

On 2/11/2025 5:47 PM, Dan Williams wrote:
> Terry Bowman wrote:
>> The AER 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.
>>
>> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> Reviewed-by: Fan Ni <fan.ni@samsung.com>
>> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
>> Reviewed-by: Gregory Price <gourry@gourry.net>
>> ---
>> drivers/pci/pcie/aer.c | 14 ++++++++------
>> include/ras/ras_event.h | 9 ++++++---
>> 2 files changed, 14 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
>> index 6e8de77d0fc4..f99a1c6fb274 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 = pcie_is_cxl(dev) ? "CXL" : "PCIe";
> I was expecting that this would be more than just a CXL link check
> because CXL AER events are only a subset of the events that can trigger
> an AER interrupt on a CXL device.
>
> Also, with CXL protocol errors the TLP log is sourced from CXL RAS
> registers and is distinct from the PCIe ->tlp in 'struct aer_err_info'.
>
> All that to say that I think this patch probably wants to decorate the
> bus type in 'struct aer_err_info' and then use that rather than just the ->is_cxl
> flag of the device.
>
> In the interest of moving the patch set along perhaps just do something
> like this for now and circle back to make it more sophisticated later:
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 01e51db8d285..eed098c134a6 100644
> --- a/drivers/pci/pci.h
> +++ 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";
> +}
> +
> 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..405f15c878ff 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1211,6 +1211,7 @@ 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 = dev->is_cxl;
>
> /* The device might not support AER */
> if (!aer)
>
> Other than that, this patch looks good to me:
>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Ok. I can add is_cxl to 'struct aer_err_info'. Shall I set it by reading the
alternate protocol link state?

Terry