On 5 Nov 2020, at 16:14, Sean V Kelley wrote:

From: Qiuxu Zhuo <qiuxu.z...@intel.com>

When attempting error recovery for an RCiEP associated with an RCEC device, there needs to be a way to update the Root Error Status, the Uncorrectable Error Status and the Uncorrectable Error Severity of the parent RCEC. In some non-native cases in which there is no OS-visible device associated
with the RCiEP, there is nothing to act upon as the firmware is acting
before the OS.

Add handling for the linked RCEC in AER/ERR while taking into account
non-native cases.

Co-developed-by: Sean V Kelley <sean.v.kel...@intel.com>
Link: https://lore.kernel.org/r/20201002184735.1229220-12-seanvk....@oregontracks.org
Signed-off-by: Sean V Kelley <sean.v.kel...@intel.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.z...@intel.com>
Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com>
---
 drivers/pci/pcie/aer.c | 35 +++++++++++++++++++++++++++--------
 drivers/pci/pcie/err.c | 20 ++++++++++----------
 2 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 4ab379fa1506..3498af81d240 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1357,29 +1357,48 @@ static int aer_probe(struct pcie_device *dev)
  */
 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 {
+       int type = pci_pcie_type(dev);
        int aer = dev->aer_cap;
+       struct pci_dev *root;
        int rc = 0;
        u32 reg32;

+       if (type == PCI_EXP_TYPE_RC_END)
+               /*
+                * The reset should only clear the Root Error Status
+                * of the RCEC. Only perform this for the
+                * native case, i.e., an RCEC is present.
+                */
+               root = dev->rcec;
+       else
+               root = dev;
+
        if (pcie_aer_is_native(dev)) {
                /* Disable Root's interrupt in response to error messages */
-               pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+               pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
                reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
-               pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+               pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
        }

-       rc = pci_bus_error_reset(dev);
-       pci_info(dev, "Root Port link has been reset (%d)\n", rc);
+       if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
+               if (pcie_has_flr(root)) {
+                       rc = pcie_flr(root);
+                       pci_info(dev, "has been reset (%d)\n", rc);
+               }
+       } else {
+               rc = pci_bus_error_reset(root);
+               pci_info(dev, "Root Port link has been reset (%d)\n", rc);
+       }

So this needs to change as I didn’t use the aer = dev->aer_cap from before because I’m checking explicitly for pcie_aer_is_native(). However, we still have the scenario of non-native and root = dev->rcec = NULL. Secondly, for the flr, that should be happening on the dev and that should trump use of the root var anyway.

So I would change it to: (replacing root with dev)

 +      if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
 +              if (pcie_has_flr(dev)) {
 +                      rc = pcie_flr(dev);
 +                      pci_info(dev, "has been reset (%d)\n", rc);
 +              }
 +      } else {
 +              rc = pci_bus_error_reset(dev);
 +              pci_info(dev, "Root Port link has been reset (%d)\n", rc);
 +      }

Thanks,

Sean



        if (pcie_aer_is_native(dev)) {
                /* Clear Root Error Status */
-               pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &reg32);
-               pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, reg32);
+               pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
+               pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);

                /* Enable Root Port's interrupt in response to error messages */
-               pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+               pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
                reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
-               pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+               pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
        }

        return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 7883c9791562..cbc5abfe767b 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -148,10 +148,10 @@ static int report_resume(struct pci_dev *dev, void *data)

 /**
  * pci_walk_bridge - walk bridges potentially AER affected
- * @bridge: bridge which may be a Port, an RCEC with associated RCiEPs,
- *             or an RCiEP associated with an RCEC
- * @cb:                callback to be called for each device found
- * @userdata:  arbitrary pointer to be passed to callback
+ * @bridge   bridge which may be an RCEC with associated RCiEPs,
+ *           or a Port.
+ * @cb       callback to be called for each device found
+ * @userdata arbitrary pointer to be passed to callback.
  *
* If the device provided is a bridge, walk the subordinate bus, including * any bridged devices on buses under this bus. Call the provided callback @@ -164,8 +164,14 @@ static void pci_walk_bridge(struct pci_dev *bridge,
                            int (*cb)(struct pci_dev *, void *),
                            void *userdata)
 {
+       /*
+        * In a non-native case where there is no OS-visible reporting
+ * device the bridge will be NULL, i.e., no RCEC, no Downstream Port.
+        */
        if (bridge->subordinate)
                pci_walk_bus(bridge->subordinate, cb, userdata);
+       else if (bridge->rcec)
+               cb(bridge->rcec, userdata);
        else
                cb(bridge, userdata);
 }
@@ -194,12 +200,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
        pci_dbg(bridge, "broadcast error_detected message\n");
        if (state == pci_channel_io_frozen) {
                pci_walk_bridge(bridge, report_frozen_detected, &status);
-               if (type == PCI_EXP_TYPE_RC_END) {
- pci_warn(dev, "subordinate device reset not possible for RCiEP\n");
-                       status = PCI_ERS_RESULT_NONE;
-                       goto failed;
-               }
-
                status = reset_subordinates(bridge);
                if (status != PCI_ERS_RESULT_RECOVERED) {
                        pci_warn(bridge, "subordinate device reset failed\n");
--
2.29.2

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