Allow userspace to read/write ratelimits per device. Create aer/ sysfs directory to store them and any future aer configs. Tested using aer-inject[1] tool. Configured correctable log/irq ratelimits to 5/10 respectively. Sent 12 AER errors. Observed 5 errors logged while AER stats (cat /sys/bus/pci/devices/<dev>/aer_dev_correctable) shows 11 (1 masked). Before: CEMsk: BadTLP- After: CEMsk: BadTLP+. [1] https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git Signed-off-by: Jon Pan-Doh <pandoh@xxxxxxxxxx> --- .../testing/sysfs-bus-pci-devices-aer_stats | 32 +++++++++++ Documentation/PCI/pcieaer-howto.rst | 4 +- drivers/pci/pci-sysfs.c | 1 + drivers/pci/pci.h | 1 + drivers/pci/pcie/aer.c | 56 +++++++++++++++++++ 5 files changed, 93 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats b/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats index d1f67bb81d5d..c680a53af0f4 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats +++ b/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats @@ -117,3 +117,35 @@ Date: July 2018 KernelVersion: 4.19.0 Contact: linux-pci@xxxxxxxxxxxxxxx, rajatja@xxxxxxxxxx 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. Provides +configurable ratelimits of logs/irq per error type. Writing a nonzero value +changes the number of errors (burst) allowed per 5 second window before +ratelimiting. Reading gets the current ratelimits. + +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_cor_irq +Date: Jan 2025 +KernelVersion: 6.14.0 +Contact: linux-pci@xxxxxxxxxxxxxxx, pandoh@xxxxxxxxxx +Description: IRQ ratelimit for correctable errors. + +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_uncor_irq +Date: Jan 2025 +KernelVersion: 6.14.0 +Contact: linux-pci@xxxxxxxxxxxxxxx, pandoh@xxxxxxxxxx +Description: IRQ ratelimit for uncorrectable errors. + +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_cor_log +Date: Jan 2025 +KernelVersion: 6.14.0 +Contact: linux-pci@xxxxxxxxxxxxxxx, pandoh@xxxxxxxxxx +Description: Log ratelimit for correctable errors. + +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_uncor_log +Date: Jan 2025 +KernelVersion: 6.14.0 +Contact: linux-pci@xxxxxxxxxxxxxxx, pandoh@xxxxxxxxxx +Description: Log ratelimit for uncorrectable errors. diff --git a/Documentation/PCI/pcieaer-howto.rst b/Documentation/PCI/pcieaer-howto.rst index d41272504b18..4d5b0638f120 100644 --- a/Documentation/PCI/pcieaer-howto.rst +++ b/Documentation/PCI/pcieaer-howto.rst @@ -89,7 +89,9 @@ AER Ratelimits ------------------------- Errors, both at log and IRQ level, are ratelimited per device and error type. -This prevents spammy devices from stalling execution. +This prevents spammy devices from stalling execution. Ratelimits are exposed +in the form of sysfs attributes and configurable. See +Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats AER Statistics / Counters ------------------------- diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 7679d75d71e5..41acb6713e2d 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1693,6 +1693,7 @@ const struct attribute_group *pci_dev_attr_groups[] = { &pcie_dev_attr_group, #ifdef CONFIG_PCIEAER &aer_stats_attr_group, + &aer_attr_group, #endif #ifdef CONFIG_PCIEASPM &aspm_ctrl_attr_group, diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 2e40fc63ba31..9d0272a890ef 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -881,6 +881,7 @@ 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; +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); diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index 1db70ae87f52..e48e2951baae 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -630,6 +630,62 @@ const struct attribute_group aer_stats_attr_group = { .is_visible = aer_stats_attrs_are_visible, }; +#define aer_ratelimit_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, "%u errors every %u seconds\n", \ + pdev->aer_info->ratelimit.burst, \ + pdev->aer_info->ratelimit.interval / HZ); \ +} \ + \ + 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 (kstrtoint(buf, 0, &burst) < 0) \ + return -EINVAL; \ + \ + pdev->aer_info->ratelimit.burst = burst; \ + return count; \ +} \ +static DEVICE_ATTR_RW(name) + +aer_ratelimit_attr(ratelimit_cor_irq, cor_irq_ratelimit); +aer_ratelimit_attr(ratelimit_uncor_irq, uncor_irq_ratelimit); +aer_ratelimit_attr(ratelimit_cor_log, cor_log_ratelimit); +aer_ratelimit_attr(ratelimit_uncor_log, uncor_log_ratelimit); + +static struct attribute *aer_attrs[] __ro_after_init = { + &dev_attr_ratelimit_cor_irq.attr, + &dev_attr_ratelimit_uncor_irq.attr, + &dev_attr_ratelimit_cor_log.attr, + &dev_attr_ratelimit_uncor_log.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) { -- 2.48.0.rc2.279.g1de40edade-goog
