Allow userspace to read/write log ratelimits per device (including
enable/disable). Create aer/ sysfs directory to store them and any
future AER configs.
The new sysfs files are:
/sys/bus/pci/devices/*/aer/correctable_ratelimit_burst
/sys/bus/pci/devices/*/aer/correctable_ratelimit_interval_ms
/sys/bus/pci/devices/*/aer/nonfatal_ratelimit_burst
/sys/bus/pci/devices/*/aer/nonfatal_ratelimit_interval_ms
The default values are ratelimit_burst=10, ratelimit_interval_ms=5000, so
if we try to emit more than 10 messages in a 5 second period, some are
suppressed.
Update AER sysfs ABI filename to reflect the broader scope of AER sysfs
attributes (e.g. stats and ratelimits).
Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats ->
sysfs-bus-pci-devices-aer
Tested using aer-inject[1]. Configured correctable log ratelimit to 5.
Sent 6 AER errors. Observed 5 errors logged while AER stats
(cat /sys/bus/pci/devices/<dev>/aer_dev_correctable) shows 6.
Disabled ratelimiting and sent 6 more AER errors. Observed all 6 errors
logged and accounted in AER stats (12 total errors).
[1] https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git
[bhelgaas: note fatal errors are not ratelimited, "aer_report" ->
"aer_info", replace ratelimit_log_enable toggle with *_ratelimit_interval_ms]
Signed-off-by: Karolina Stolarek <karolina.stolarek@oracle.com>
Signed-off-by: Jon Pan-Doh <pandoh@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-21-helgaas@kernel.org
--- /dev/null
+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).
+
+What: /sys/bus/pci/devices/<dev>/aer_dev_correctable
+Date: July 2018
+KernelVersion: 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
+
+What: /sys/bus/pci/devices/<dev>/aer_dev_fatal
+Date: July 2018
+KernelVersion: 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
+
+What: /sys/bus/pci/devices/<dev>/aer_dev_nonfatal
+Date: July 2018
+KernelVersion: 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
+
+PCIe Rootport AER statistics
+----------------------------
+
+These attributes show up under only the rootports (or root complex event
+collectors) that are AER capable. These indicate the number of error messages as
+"reported to" the rootport. Please note that the rootports also transmit
+(internally) the ERR_* messages for errors seen by the internal rootport PCI
+device, so these counters include them and are thus cumulative of all the error
+messages on the PCI hierarchy originating at that root port.
+
+What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_cor
+Date: July 2018
+KernelVersion: 4.19.0
+Contact: linux-pci@vger.kernel.org, rajatja@google.com
+Description: Total number of ERR_COR messages reported to rootport.
+
+What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_fatal
+Date: July 2018
+KernelVersion: 4.19.0
+Contact: linux-pci@vger.kernel.org, rajatja@google.com
+Description: Total number of ERR_FATAL messages reported to rootport.
+
+What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_nonfatal
+Date: July 2018
+KernelVersion: 4.19.0
+Contact: linux-pci@vger.kernel.org, rajatja@google.com
+Description: Total number of ERR_NONFATAL messages reported to rootport.
+
+PCIe AER ratelimits
+-------------------
+
+These attributes show up under all the devices that are AER capable.
+They represent configurable ratelimits of logs per error type.
+
+See Documentation/PCI/pcieaer-howto.rst for more info on ratelimits.
+
+What: /sys/bus/pci/devices/<dev>/aer/correctable_ratelimit_interval_ms
+Date: May 2025
+KernelVersion: 6.16.0
+Contact: linux-pci@vger.kernel.org
+Description: Writing 0 disables AER correctable error log ratelimiting.
+ Writing a positive value sets the ratelimit interval in ms.
+ Default is DEFAULT_RATELIMIT_INTERVAL (5000 ms).
+
+What: /sys/bus/pci/devices/<dev>/aer/correctable_ratelimit_burst
+Date: May 2025
+KernelVersion: 6.16.0
+Contact: linux-pci@vger.kernel.org
+Description: Ratelimit burst for correctable error logs. Writing a value
+ changes the number of errors (burst) allowed per interval
+ before ratelimiting. Reading gets the current ratelimit
+ burst. Default is DEFAULT_RATELIMIT_BURST (10).
+
+What: /sys/bus/pci/devices/<dev>/aer/nonfatal_ratelimit_interval_ms
+Date: May 2025
+KernelVersion: 6.16.0
+Contact: linux-pci@vger.kernel.org
+Description: Writing 0 disables AER non-fatal uncorrectable error log
+ ratelimiting. Writing a positive value sets the ratelimit
+ interval in ms. Default is DEFAULT_RATELIMIT_INTERVAL
+ (5000 ms).
+
+What: /sys/bus/pci/devices/<dev>/aer/nonfatal_ratelimit_burst
+Date: May 2025
+KernelVersion: 6.16.0
+Contact: linux-pci@vger.kernel.org
+Description: Ratelimit burst for non-fatal uncorrectable error logs.
+ Writing a value changes the number of errors (burst)
+ allowed per interval before ratelimiting. Reading gets the
+ current ratelimit burst. Default is DEFAULT_RATELIMIT_BURST
+ (10).
+++ /dev/null
-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).
-
-What: /sys/bus/pci/devices/<dev>/aer_dev_correctable
-Date: July 2018
-KernelVersion: 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
-
-What: /sys/bus/pci/devices/<dev>/aer_dev_fatal
-Date: July 2018
-KernelVersion: 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
-
-What: /sys/bus/pci/devices/<dev>/aer_dev_nonfatal
-Date: July 2018
-KernelVersion: 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
-
-PCIe Rootport AER statistics
-----------------------------
-
-These attributes show up under only the rootports (or root complex event
-collectors) that are AER capable. These indicate the number of error messages as
-"reported to" the rootport. Please note that the rootports also transmit
-(internally) the ERR_* messages for errors seen by the internal rootport PCI
-device, so these counters include them and are thus cumulative of all the error
-messages on the PCI hierarchy originating at that root port.
-
-What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_cor
-Date: July 2018
-KernelVersion: 4.19.0
-Contact: linux-pci@vger.kernel.org, rajatja@google.com
-Description: Total number of ERR_COR messages reported to rootport.
-
-What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_fatal
-Date: July 2018
-KernelVersion: 4.19.0
-Contact: linux-pci@vger.kernel.org, rajatja@google.com
-Description: Total number of ERR_FATAL messages reported to rootport.
-
-What: /sys/bus/pci/devices/<dev>/aer_rootport_total_err_nonfatal
-Date: July 2018
-KernelVersion: 4.19.0
-Contact: linux-pci@vger.kernel.org, rajatja@google.com
-Description: Total number of ERR_NONFATAL messages reported to rootport.
AER uses the default ratelimit of DEFAULT_RATELIMIT_BURST (10 events) over
DEFAULT_RATELIMIT_INTERVAL (5 seconds).
+Ratelimits are exposed in the form of sysfs attributes and configurable.
+See Documentation/ABI/testing/sysfs-bus-pci-devices-aer.
+
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
+Documentation/ABI/testing/sysfs-bus-pci-devices-aer.
Developer Guide
===============
&pcie_dev_attr_group,
#ifdef CONFIG_PCIEAER
&aer_stats_attr_group,
+ &aer_attr_group,
#endif
#ifdef CONFIG_PCIEASPM
&aspm_ctrl_attr_group,
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;
+extern const struct attribute_group aer_attr_group;
void pci_aer_clear_fatal_status(struct pci_dev *dev);
int pci_aer_clear_status(struct pci_dev *dev);
int pci_aer_raw_clear_status(struct pci_dev *dev);
.is_visible = aer_stats_attrs_are_visible,
};
+/*
+ * Ratelimit interval
+ * <=0: disabled with ratelimit.interval = 0
+ * >0: enabled with ratelimit.interval in ms
+ */
+#define aer_ratelimit_interval_attr(name, ratelimit) \
+ static ssize_t \
+ name##_show(struct device *dev, struct device_attribute *attr, \
+ char *buf) \
+ { \
+ struct pci_dev *pdev = to_pci_dev(dev); \
+ \
+ return sysfs_emit(buf, "%d\n", \
+ pdev->aer_info->ratelimit.interval); \
+ } \
+ \
+ static ssize_t \
+ name##_store(struct device *dev, struct device_attribute *attr, \
+ const char *buf, size_t count) \
+ { \
+ struct pci_dev *pdev = to_pci_dev(dev); \
+ int interval; \
+ \
+ if (!capable(CAP_SYS_ADMIN)) \
+ return -EPERM; \
+ \
+ if (kstrtoint(buf, 0, &interval) < 0) \
+ return -EINVAL; \
+ \
+ if (interval <= 0) \
+ interval = 0; \
+ else \
+ interval = msecs_to_jiffies(interval); \
+ \
+ pdev->aer_info->ratelimit.interval = interval; \
+ \
+ return count; \
+ } \
+ static DEVICE_ATTR_RW(name);
+
+#define aer_ratelimit_burst_attr(name, ratelimit) \
+ static ssize_t \
+ name##_show(struct device *dev, struct device_attribute *attr, \
+ char *buf) \
+ { \
+ struct pci_dev *pdev = to_pci_dev(dev); \
+ \
+ return sysfs_emit(buf, "%d\n", \
+ pdev->aer_info->ratelimit.burst); \
+ } \
+ \
+ static ssize_t \
+ name##_store(struct device *dev, struct device_attribute *attr, \
+ const char *buf, size_t count) \
+ { \
+ struct pci_dev *pdev = to_pci_dev(dev); \
+ int burst; \
+ \
+ if (!capable(CAP_SYS_ADMIN)) \
+ return -EPERM; \
+ \
+ if (kstrtoint(buf, 0, &burst) < 0) \
+ return -EINVAL; \
+ \
+ pdev->aer_info->ratelimit.burst = burst; \
+ \
+ return count; \
+ } \
+ static DEVICE_ATTR_RW(name);
+
+#define aer_ratelimit_attrs(name) \
+ aer_ratelimit_interval_attr(name##_ratelimit_interval_ms, \
+ name##_ratelimit) \
+ aer_ratelimit_burst_attr(name##_ratelimit_burst, \
+ name##_ratelimit)
+
+aer_ratelimit_attrs(correctable)
+aer_ratelimit_attrs(nonfatal)
+
+static struct attribute *aer_attrs[] = {
+ &dev_attr_correctable_ratelimit_interval_ms.attr,
+ &dev_attr_correctable_ratelimit_burst.attr,
+ &dev_attr_nonfatal_ratelimit_interval_ms.attr,
+ &dev_attr_nonfatal_ratelimit_burst.attr,
+ NULL
+};
+
+static umode_t aer_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_info)
+ return 0;
+
+ return a->mode;
+}
+
+const struct attribute_group aer_attr_group = {
+ .name = "aer",
+ .attrs = aer_attrs,
+ .is_visible = aer_attrs_are_visible,
+};
+
static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
struct aer_err_info *info)
{