Re: [PATCH] PCI/AER: add pcie TLP header information in the tracepoint

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Steve, Alex]

On Mon, Apr 02, 2018 at 11:47:08AM -0400, Thomas Tai wrote:
> When a PCIe AER occurs, the TLP header information is
> printed in the kernel message but it is missing from
> the tracepoint. A userspace program can use this information
> in the tracepoint to better analyze problems.
> 
> Example tracepoint output:
> aer_event: 0000:01:00.0
> PCIe Bus Error: severity=Uncorrected, non-fatal, Completer Abort
> TLP Header={0x0,0x1,0x2,0x3}
> 
> Signed-off-by: Thomas Tai <thomas.tai@oracle.com>

I tentatively applied this to pci/aer for v4.18, thanks!

Steve, let me know if you have any comments.

Alex, I just copied you because you've been unifying the AER native and
CPER paths, and this is another case of code that appears in both paths.
FYI only, no action required :)

> ---
>  drivers/pci/pcie/aer/aerdrv_errprint.c |  4 ++--
>  include/ras/ras_event.h                | 20 ++++++++++++++++----
>  2 files changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/pcie/aer/aerdrv_errprint.c b/drivers/pci/pcie/aer/aerdrv_errprint.c
> index 6a352e638699..0a78a773bd25 100644
> --- a/drivers/pci/pcie/aer/aerdrv_errprint.c
> +++ b/drivers/pci/pcie/aer/aerdrv_errprint.c
> @@ -192,7 +192,7 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  		pci_err(dev, "  Error of this Agent(%04x) is reported first\n", id);
>  
>  	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
> -			info->severity);
> +			info->severity, info->tlp_header_valid, &info->tlp);
>  }
>  
>  void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
> @@ -252,6 +252,6 @@ void cper_print_aer(struct pci_dev *dev, int aer_severity,
>  		__print_tlp_header(dev, &aer->header_log);
>  
>  	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
> -			aer_severity);
> +			aer_severity, tlp_header_valid, &aer->header_log);
>  }
>  #endif
> diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
> index 9c689868eb4d..90f59556f595 100644
> --- a/include/ras/ras_event.h
> +++ b/include/ras/ras_event.h
> @@ -298,30 +298,42 @@ TRACE_EVENT(non_standard_event,
>  TRACE_EVENT(aer_event,
>  	TP_PROTO(const char *dev_name,
>  		 const u32 status,
> -		 const u8 severity),
> +		 const u8 severity,
> +		 const u32 tlp_header_valid,
> +		 struct aer_header_log_regs *tlp),
>  
> -	TP_ARGS(dev_name, status, severity),
> +	TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp),
>  
>  	TP_STRUCT__entry(
>  		__string(	dev_name,	dev_name	)
>  		__field(	u32,		status		)
>  		__field(	u8,		severity	)
> +		__field(	u32, 		tlp_header_valid)
> +		__array(	u32, 		buf, 4		)
>  	),
>  
>  	TP_fast_assign(
>  		__assign_str(dev_name, dev_name);
>  		__entry->status		= status;
>  		__entry->severity	= severity;
> +		__entry->tlp_header_valid = tlp_header_valid;
> +		__entry->buf[0] = tlp->dw0;
> +		__entry->buf[1] = tlp->dw1;
> +		__entry->buf[2] = tlp->dw2;
> +		__entry->buf[3] = tlp->dw3;
>  	),
>  
> -	TP_printk("%s PCIe Bus Error: severity=%s, %s\n",
> +	TP_printk("%s PCIe Bus Error: severity=%s, %s, TLP Header=%s\n",
>  		__get_str(dev_name),
>  		__entry->severity == AER_CORRECTABLE ? "Corrected" :
>  			__entry->severity == AER_FATAL ?
>  			"Fatal" : "Uncorrected, non-fatal",
>  		__entry->severity == AER_CORRECTABLE ?
>  		__print_flags(__entry->status, "|", aer_correctable_errors) :
> -		__print_flags(__entry->status, "|", aer_uncorrectable_errors))
> +		__print_flags(__entry->status, "|", aer_uncorrectable_errors),
> +		__entry->tlp_header_valid ?
> +			__print_array(__entry->buf, 4, sizeof(unsigned int)) :
> +			"Not available")
>  );
>  
>  /*
> -- 
> 2.14.1
>