Re: [PATCH] PCI/AER: Print TLP Log for errors introduced since PCIe r1.1

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Sep 01, 2025 at 09:44:52AM +0200, Lukas Wunner wrote:
> When reporting an error, the AER driver prints the TLP Header / Prefix Log
> only for errors enumerated in the AER_LOG_TLP_MASKS macro.
> 
> The macro was never amended since its introduction in 2006 with commit
> 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver").
> At the time, PCIe r1.1 was the latest spec revision.
> 
> Amend the macro with errors defined since then to avoid omitting the TLP
> Header / Prefix Log for newer errors.
> 
> The order of the errors in AER_LOG_TLP_MASKS follows PCIe r1.1 sec 6.2.7
> rather than 7.10.2, because only the former documents for which errors a
> TLP Header / Prefix is logged.  Retain this order.  The section number is
> still 6.2.7 in today's PCIe r7.0.
> 
> For Completion Timeouts, the TLP Header / Prefix is only logged if the
> Completion Timeout Prefix / Header Log Capable bit is set in the AER
> Capabilities and Control register.  Introduce a tlp_header_logged() helper
> to check whether the TLP Header / Prefix Log is populated and use it in
> the two places which currently match against AER_LOG_TLP_MASKS directly.
> 
> For Uncorrectable Internal Errors, logging of the TLP Header / Prefix is
> optional per PCIe r7.0 sec 6.2.7.  If needed, drivers could indicate
> through a flag whether devices are capable and tlp_header_logged() could
> then check that flag.
> 
> pcitools introduced macros for newer errors with commit 144b0911cc0b
> ("ls-ecaps: extend decode support for more fields for AER CE and UE
> status"):
>   https://git.kernel.org/pub/scm/utils/pciutils/pciutils.git/commit/?id=144b0911cc0b
> 
> Unfortunately some of those macros are overly long:
>   PCI_ERR_UNC_POISONED_TLP_EGRESS
>   PCI_ERR_UNC_DMWR_REQ_EGRESS_BLOCKED
>   PCI_ERR_UNC_IDE_CHECK
>   PCI_ERR_UNC_MISR_IDE_TLP
>   PCI_ERR_UNC_PCRC_CHECK
>   PCI_ERR_UNC_TLP_XLAT_EGRESS_BLOCKED
> 
> This seems unsuitable for <linux/pci_regs.h>, so shorten to:
>   PCI_ERR_UNC_POISON_BLK
>   PCI_ERR_UNC_DMWR_BLK
>   PCI_ERR_UNC_IDE_CHECK
>   PCI_ERR_UNC_MISR_IDE
>   PCI_ERR_UNC_PCRC_CHECK
>   PCI_ERR_UNC_XLAT_BLK
> 
> Note that some of the existing macros in <linux/pci_regs.h> do not match
> exactly with pcitools (e.g. PCI_ERR_UNC_SDES versus PCI_ERR_UNC_SURPDN),
> so it does not seem mandatory for them to be identical.
> 
> Signed-off-by: Lukas Wunner <lukas@wunner.de>

Applied to pci/aer for v6.18, thanks, Lukas!

> ---
>  drivers/pci/pcie/aer.c        | 30 +++++++++++++++++++++++++++---
>  include/uapi/linux/pci_regs.h |  8 ++++++++
>  2 files changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 15ed541..62c74b5 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -96,11 +96,21 @@ struct aer_info {
>  };
>  
>  #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
> +					PCI_ERR_UNC_POISON_BLK |	\
>  					PCI_ERR_UNC_ECRC|		\
>  					PCI_ERR_UNC_UNSUP|		\
>  					PCI_ERR_UNC_COMP_ABORT|		\
>  					PCI_ERR_UNC_UNX_COMP|		\
> -					PCI_ERR_UNC_MALF_TLP)
> +					PCI_ERR_UNC_ACSV |		\
> +					PCI_ERR_UNC_MCBTLP |		\
> +					PCI_ERR_UNC_ATOMEG |		\
> +					PCI_ERR_UNC_DMWR_BLK |		\
> +					PCI_ERR_UNC_XLAT_BLK |		\
> +					PCI_ERR_UNC_TLPPRE |		\
> +					PCI_ERR_UNC_MALF_TLP |		\
> +					PCI_ERR_UNC_IDE_CHECK |		\
> +					PCI_ERR_UNC_MISR_IDE |		\
> +					PCI_ERR_UNC_PCRC_CHECK)
>  
>  #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
>  					PCI_EXP_RTCTL_SENFEE|	\
> @@ -796,6 +806,20 @@ static int aer_ratelimit(struct pci_dev *dev, unsigned int severity)
>  	}
>  }
>  
> +static bool tlp_header_logged(u32 status, u32 capctl)
> +{
> +	/* Errors for which a header is always logged (PCIe r7.0 sec 6.2.7) */
> +	if (status & AER_LOG_TLP_MASKS)
> +		return true;
> +
> +	/* Completion Timeout header is only logged on capable devices */
> +	if (status & PCI_ERR_UNC_COMP_TIME &&
> +	    capctl & PCI_ERR_CAP_COMP_TIME_LOG)
> +		return true;
> +
> +	return false;
> +}
> +
>  static void __aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  {
>  	const char **strings;
> @@ -910,7 +934,7 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  		status = aer->uncor_status;
>  		mask = aer->uncor_mask;
>  		info.level = KERN_ERR;
> -		tlp_header_valid = status & AER_LOG_TLP_MASKS;
> +		tlp_header_valid = tlp_header_logged(status, aer->cap_control);
>  	}
>  
>  	info.status = status;
> @@ -1401,7 +1425,7 @@ int aer_get_device_error_info(struct aer_err_info *info, int i)
>  		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &aercc);
>  		info->first_error = PCI_ERR_CAP_FEP(aercc);
>  
> -		if (info->status & AER_LOG_TLP_MASKS) {
> +		if (tlp_header_logged(info->status, aercc)) {
>  			info->tlp_header_valid = 1;
>  			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG,
>  					  aer + PCI_ERR_PREFIX_LOG,
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index f5b1774..d2e1bbb 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -776,6 +776,13 @@
>  #define  PCI_ERR_UNC_MCBTLP	0x00800000	/* MC blocked TLP */
>  #define  PCI_ERR_UNC_ATOMEG	0x01000000	/* Atomic egress blocked */
>  #define  PCI_ERR_UNC_TLPPRE	0x02000000	/* TLP prefix blocked */
> +#define  PCI_ERR_UNC_POISON_BLK	0x04000000	/* Poisoned TLP Egress Blocked */
> +#define  PCI_ERR_UNC_DMWR_BLK	0x08000000	/* DMWr Request Egress Blocked */
> +#define  PCI_ERR_UNC_IDE_CHECK	0x10000000	/* IDE Check Failed */
> +#define  PCI_ERR_UNC_MISR_IDE	0x20000000	/* Misrouted IDE TLP */
> +#define  PCI_ERR_UNC_PCRC_CHECK	0x40000000	/* PCRC Check Failed */
> +#define  PCI_ERR_UNC_XLAT_BLK	0x80000000	/* TLP Translation Egress Blocked */
> +
>  #define PCI_ERR_UNCOR_MASK	0x08	/* Uncorrectable Error Mask */
>  	/* Same bits as above */
>  #define PCI_ERR_UNCOR_SEVER	0x0c	/* Uncorrectable Error Severity */
> @@ -798,6 +805,7 @@
>  #define  PCI_ERR_CAP_ECRC_CHKC		0x00000080 /* ECRC Check Capable */
>  #define  PCI_ERR_CAP_ECRC_CHKE		0x00000100 /* ECRC Check Enable */
>  #define  PCI_ERR_CAP_PREFIX_LOG_PRESENT	0x00000800 /* TLP Prefix Log Present */
> +#define  PCI_ERR_CAP_COMP_TIME_LOG	0x00001000 /* Completion Timeout Prefix/Header Log Capable */
>  #define  PCI_ERR_CAP_TLP_LOG_FLIT	0x00040000 /* TLP was logged in Flit Mode */
>  #define  PCI_ERR_CAP_TLP_LOG_SIZE	0x00f80000 /* Logged TLP Size (only in Flit mode) */
>  #define PCI_ERR_HEADER_LOG	0x1c	/* Header Log Register (16 bytes) */
> -- 
> 2.50.1
>