PCI/AER: Add sysfs attributes to provide AER stats and breakdown (81aa5206) · Commits · e / devices / android_kernel_teracube_emerald

Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats

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Original line number	Diff line number	Diff line
		==========================
		PCIe Device AER statistics
		==========================
		These attributes show up under all the devices that are AER capable. These
		statistical counters indicate the errors "as seen/reported by the device".
		Note that this may mean that if an endpoint is causing problems, the AER
		counters may increment at its link partner (e.g. root port) because the
		errors may be "seen" / reported by the link partner and not the
		problematic endpoint itself (which may report all counters as 0 as it never
		saw any problems).

		Where: /sys/bus/pci/devices/<dev>/aer_dev_correctable
		Date: July 2018
		Kernel Version: 4.19.0
		Contact: linux-pci@vger.kernel.org, rajatja@google.com
		Description: List of correctable errors seen and reported by this
		PCI device using ERR_COR. Note that since multiple errors may
		be reported using a single ERR_COR message, thus
		TOTAL_ERR_COR at the end of the file may not match the actual
		total of all the errors in the file. Sample output:
		-------------------------------------------------------------------------
		localhost /sys/devices/pci0000:00/0000:00:1c.0 # cat aer_dev_correctable
		Receiver Error 2
		Bad TLP 0
		Bad DLLP 0
		RELAY_NUM Rollover 0
		Replay Timer Timeout 0
		Advisory Non-Fatal 0
		Corrected Internal Error 0
		Header Log Overflow 0
		TOTAL_ERR_COR 2
		-------------------------------------------------------------------------

		Where: /sys/bus/pci/devices/<dev>/aer_dev_fatal
		Date: July 2018
		Kernel Version: 4.19.0
		Contact: linux-pci@vger.kernel.org, rajatja@google.com
		Description: List of uncorrectable fatal errors seen and reported by this
		PCI device using ERR_FATAL. Note that since multiple errors may
		be reported using a single ERR_FATAL message, thus
		TOTAL_ERR_FATAL at the end of the file may not match the actual
		total of all the errors in the file. Sample output:
		-------------------------------------------------------------------------
		localhost /sys/devices/pci0000:00/0000:00:1c.0 # cat aer_dev_fatal
		Undefined 0
		Data Link Protocol 0
		Surprise Down Error 0
		Poisoned TLP 0
		Flow Control Protocol 0
		Completion Timeout 0
		Completer Abort 0
		Unexpected Completion 0
		Receiver Overflow 0
		Malformed TLP 0
		ECRC 0
		Unsupported Request 0
		ACS Violation 0
		Uncorrectable Internal Error 0
		MC Blocked TLP 0
		AtomicOp Egress Blocked 0
		TLP Prefix Blocked Error 0
		TOTAL_ERR_FATAL 0
		-------------------------------------------------------------------------

		Where: /sys/bus/pci/devices/<dev>/aer_dev_nonfatal
		Date: July 2018
		Kernel Version: 4.19.0
		Contact: linux-pci@vger.kernel.org, rajatja@google.com
		Description: List of uncorrectable nonfatal errors seen and reported by this
		PCI device using ERR_NONFATAL. Note that since multiple errors
		may be reported using a single ERR_FATAL message, thus
		TOTAL_ERR_NONFATAL at the end of the file may not match the
		actual total of all the errors in the file. Sample output:
		-------------------------------------------------------------------------
		localhost /sys/devices/pci0000:00/0000:00:1c.0 # cat aer_dev_nonfatal
		Undefined 0
		Data Link Protocol 0
		Surprise Down Error 0
		Poisoned TLP 0
		Flow Control Protocol 0
		Completion Timeout 0
		Completer Abort 0
		Unexpected Completion 0
		Receiver Overflow 0
		Malformed TLP 0
		ECRC 0
		Unsupported Request 0
		ACS Violation 0
		Uncorrectable Internal Error 0
		MC Blocked TLP 0
		AtomicOp Egress Blocked 0
		TLP Prefix Blocked Error 0
		TOTAL_ERR_NONFATAL 0
		-------------------------------------------------------------------------

Documentation/PCI/pcieaer-howto.txt

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Original line number	Diff line number	Diff line
		@@ -73,6 +73,11 @@ In the example, 'Requester ID' means the ID of the device who sends
		the error message to root port. Pls. refer to pci express specs for
		other fields.

		2.4 AER Statistics / Counters

		When PCIe AER errors are captured, the counters / statistics are also exposed
		in the form of sysfs attributes which are documented at
		Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats

		3. Developer Guide

drivers/pci/pci-sysfs.c

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		@@ -1746,6 +1746,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
		#endif
		&pci_bridge_attr_group,
		&pcie_dev_attr_group,
		#ifdef CONFIG_PCIEAER
		&aer_stats_attr_group,
		#endif
		NULL,
		};

drivers/pci/pci.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -484,6 +484,7 @@ static inline int devm_of_pci_get_host_bridge_resources(struct device *dev,
		void pci_no_aer(void);
		void pci_aer_init(struct pci_dev *dev);
		void pci_aer_exit(struct pci_dev *dev);
		extern const struct attribute_group aer_stats_attr_group;
		#else
		static inline void pci_no_aer(void) { }
		static inline int pci_aer_init(struct pci_dev *d) { return -ENODEV; }

drivers/pci/pcie/aer.c

+94 −0

Original line number	Diff line number	Diff line
		@@ -542,6 +542,99 @@ static const char *aer_agent_string[] = {
		"Transmitter ID"
		};

		#define aer_stats_dev_attr(name, stats_array, strings_array, \
		total_string, total_field) \
		static ssize_t \
		name##_show(struct device dev, struct device_attribute attr, \
		char *buf) \
		{ \
		unsigned int i; \
		char *str = buf; \
		struct pci_dev *pdev = to_pci_dev(dev); \
		u64 *stats = pdev->aer_stats->stats_array; \
		\
		for (i = 0; i < ARRAY_SIZE(strings_array); i++) { \
		if (strings_array[i]) \
		str += sprintf(str, "%s %llu\n", \
		strings_array[i], stats[i]); \
		else if (stats[i]) \
		str += sprintf(str, #stats_array "_bit[%d] %llu\n",\
		i, stats[i]); \
		} \
		str += sprintf(str, "TOTAL_%s %llu\n", total_string, \
		pdev->aer_stats->total_field); \
		return str-buf; \
		} \
		static DEVICE_ATTR_RO(name)

		aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
		aer_correctable_error_string, "ERR_COR",
		dev_total_cor_errs);
		aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
		aer_uncorrectable_error_string, "ERR_FATAL",
		dev_total_fatal_errs);
		aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
		aer_uncorrectable_error_string, "ERR_NONFATAL",
		dev_total_nonfatal_errs);

		static struct attribute *aer_stats_attrs[] __ro_after_init = {
		&dev_attr_aer_dev_correctable.attr,
		&dev_attr_aer_dev_fatal.attr,
		&dev_attr_aer_dev_nonfatal.attr,
		NULL
		};

		static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
		struct attribute *a, int n)
		{
		struct device *dev = kobj_to_dev(kobj);
		struct pci_dev *pdev = to_pci_dev(dev);

		if (!pdev->aer_stats)
		return 0;

		return a->mode;
		}

		const struct attribute_group aer_stats_attr_group = {
		.attrs = aer_stats_attrs,
		.is_visible = aer_stats_attrs_are_visible,
		};

		static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
		struct aer_err_info *info)
		{
		int status, i, max = -1;
		u64 *counter = NULL;
		struct aer_stats *aer_stats = pdev->aer_stats;

		if (!aer_stats)
		return;

		switch (info->severity) {
		case AER_CORRECTABLE:
		aer_stats->dev_total_cor_errs++;
		counter = &aer_stats->dev_cor_errs[0];
		max = AER_MAX_TYPEOF_COR_ERRS;
		break;
		case AER_NONFATAL:
		aer_stats->dev_total_nonfatal_errs++;
		counter = &aer_stats->dev_nonfatal_errs[0];
		max = AER_MAX_TYPEOF_UNCOR_ERRS;
		break;
		case AER_FATAL:
		aer_stats->dev_total_fatal_errs++;
		counter = &aer_stats->dev_fatal_errs[0];
		max = AER_MAX_TYPEOF_UNCOR_ERRS;
		break;
		}

		status = (info->status & ~info->mask);
		for (i = 0; i < max; i++)
		if (status & (1 << i))
		counter[i]++;
		}

		static void __print_tlp_header(struct pci_dev *dev,
		struct aer_header_log_regs *t)
		{
		@@ -574,6 +667,7 @@ static void __aer_print_error(struct pci_dev *dev,
		pci_err(dev, " [%2d] Unknown Error Bit%s\n",
		i, info->first_error == i ? " (First)" : "");
		}
		pci_dev_aer_stats_incr(dev, info);
		}

		void aer_print_error(struct pci_dev dev, struct aer_err_info info)