On Thu, Jun 21, 2018 at 6:17 AM, Bjorn Helgaas [off-list ref] wrote:

On Wed, Jun 20, 2018 at 04:41:43PM -0700, Rajat Jain wrote:

quoted

Define a structure to hold the AER statistics. There are 2 groups
of statistics: dev_* counters that are to be collected for all AER
capable devices and rootport_* counters that are collected for all
(AER capable) rootports only. Allocate and free this structure when
device is added or released (thus counters survive the lifetime of the
device).

Signed-off-by: Rajat Jain <redacted>
---
v5: Same as v4
v4: Same as v3
v3: Merge everything in aer.c

 drivers/pci/pcie/aer.c | 60 ++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/probe.c    |  1 +
 include/linux/pci.h    |  3 +++
 3 files changed, 64 insertions(+)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index a2e88386af28..f9fa994b6c33 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c

@@ -33,6 +33,9 @@
 #define AER_ERROR_SOURCES_MAX                100
 #define AER_MAX_MULTI_ERR_DEVICES    5       /* Not likely to have more */

+#define AER_MAX_TYPEOF_CORRECTABLE_ERRS 16   /* as per PCI_ERR_COR_STATUS */
+#define AER_MAX_TYPEOF_UNCORRECTABLE_ERRS 26 /* as per PCI_ERR_UNCOR_STATUS*/
+
 struct aer_err_info {
      struct pci_dev *dev[AER_MAX_MULTI_ERR_DEVICES];
      int error_dev_num;

@@ -76,6 +79,40 @@ struct aer_rpc {
                                       */
 };

+/* AER stats for the device */
+struct aer_stats {
+
+     /*
+      * Fields for all AER capable devices. They indicate the errors
+      * "as seen by this device". Note that this may mean that if an
+      * end point is causing problems, the AER counters may increment
+      * at its link partner (e.g. root port) because the errors will be
+      * "seen" by the link partner and not the the problematic end point
+      * itself (which may report all counters as 0 as it never saw any
+      * problems).
+      */
+     /* Individual counters for different type of correctable errors */
+     u64 dev_cor_errs[AER_MAX_TYPEOF_CORRECTABLE_ERRS];
+     /* Individual counters for different type of uncorrectable errors */
+     u64 dev_uncor_errs[AER_MAX_TYPEOF_UNCORRECTABLE_ERRS];
+     /* Total number of correctable errors seen by this device */
+     u64 dev_total_cor_errs;
+     /* Total number of fatal uncorrectable errors seen by this device */
+     u64 dev_total_fatal_errs;
+     /* Total number of fatal uncorrectable errors seen by this device */
+     u64 dev_total_nonfatal_errs;
+
+     /*
+      * Fields for Root ports only, these indicate the total number of
+      * ERR_COR, ERR_FATAL, and ERR_NONFATAL messages received by the
+      * rootport, INCLUDING the ones that are generated internally (by
+      * the rootport itself)

Strictly speaking, I think these are applicable for both root ports
and root complex event collectors, right?

Correct, I will reword this comment to state this.

quoted

+      */
+     u64 rootport_total_cor_errs;
+     u64 rootport_total_fatal_errs;
+     u64 rootport_total_nonfatal_errs;
+};
+
 #define AER_LOG_TLP_MASKS            (PCI_ERR_UNC_POISON_TLP|        \
                                      PCI_ERR_UNC_ECRC|               \
                                      PCI_ERR_UNC_UNSUP|              \

@@ -402,12 +439,35 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
      return 0;
 }

+static int pci_aer_stats_init(struct pci_dev *pdev)
+{
+     pdev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
+     if (!pdev->aer_stats) {
+             dev_err(&pdev->dev, "No memory for aer_stats\n");

pci_err(), if we need the message at all.

Based on c7abb2352c29 ("PCI: Remove unnecessary messages for memory
allocation failures"), I'd be inclined to drop the message completely.

Will do.

quoted

+             return -ENOMEM;
+     }
+     return 0;
+}
+
+static void pci_aer_stats_exit(struct pci_dev *pdev)
+{
+     kfree(pdev->aer_stats);
+     pdev->aer_stats = NULL;
+}
+
 int pci_aer_init(struct pci_dev *dev)
 {
      dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+     if (!dev->aer_cap || pci_aer_stats_init(dev))
+             return -EIO;

This skips pci_cleanup_aer_error_status_regs() if the kzalloc() fails.
I think we should still do pci_cleanup_aer_error_status_regs(), even
if the alloc fails.

Will do.

Nobody checks the return value of pci_aer_init(), so I think you can
simplify this by making these functions void.

Will do.

Maybe even squash them together, i.e., do the kzalloc() directly in
pci_aer_init() and the kfree() directly in pci_aer_exit()?

Will do.

quoted

      return pci_cleanup_aer_error_status_regs(dev);
 }

+void pci_aer_exit(struct pci_dev *dev)
+{
+     pci_aer_stats_exit(dev);
+}
+
 #define AER_AGENT_RECEIVER           0
 #define AER_AGENT_REQUESTER          1
 #define AER_AGENT_COMPLETER          2

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ac876e32de4b..48edd0c9e4bc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c

@@ -2064,6 +2064,7 @@ static void pci_configure_device(struct pci_dev *dev)

 static void pci_release_capabilities(struct pci_dev *dev)
 {
+     pci_aer_exit(dev);
      pci_vpd_release(dev);
      pci_iov_release(dev);
      pci_free_cap_save_buffers(dev);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 340029b2fb38..8d59c6c19a19 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -299,6 +299,7 @@ struct pci_dev {
      u8              hdr_type;       /* PCI header type (`multi' flag masked out) */
 #ifdef CONFIG_PCIEAER
      u16             aer_cap;        /* AER capability offset */
+     struct aer_stats *aer_stats;    /* AER stats for this device */
 #endif
      u8              pcie_cap;       /* PCIe capability offset */
      u8              msi_cap;        /* MSI capability offset */

@@ -1471,10 +1472,12 @@ static inline bool pcie_aspm_support_enabled(void) { return false; }
 void pci_no_aer(void);
 bool pci_aer_available(void);
 int pci_aer_init(struct pci_dev *dev);
+void pci_aer_exit(struct pci_dev *dev);

With the exception of pci_aer_available(), these are only used inside
drivers/pci.  This might be a good opportunity to move those private
things to drivers/pci/pci.h (in a separate patch, of course).

Will do.

quoted

 #else
 static inline void pci_no_aer(void) { }
 static inline bool pci_aer_available(void) { return false; }
 static inline int pci_aer_init(struct pci_dev *d) { return -ENODEV; }
+static inline void pci_aer_exit(struct pci_dev *d) { }
 #endif

 #ifdef CONFIG_PCIE_ECRC
--
2.18.0.rc1.244.gcf134e6275-goog

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