platform/x86/intel/vsec: Add PCI error recovery support to Intel PMT

Add PCI error recovery support for Intel PMT driver to recover
from PCI fatal errors

Cc: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Cc: David E Box <david.e.box@intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@linux.intel.com>
Link: https://lore.kernel.org/r/20220629221334.434307-5-gayatri.kammela@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index 9368a3d..70c76f5 100644 (file)
--- a/drivers/platform/x86/intel/vsec.c
+++ b/drivers/platform/x86/intel/vsec.c
@@ -15,6 +15,7 @@
 
 #include <linux/auxiliary_bus.h>
 #include <linux/bits.h>
+#include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/idr.h>
 #include <linux/module.h>
@@ -30,9 +31,13 @@
 #define INTEL_DVSEC_TABLE_BAR(x)       ((x) & GENMASK(2, 0))
 #define INTEL_DVSEC_TABLE_OFFSET(x)    ((x) & GENMASK(31, 3))
 #define TABLE_OFFSET_SHIFT             3
+#define PMT_XA_START                   0
+#define PMT_XA_MAX                     INT_MAX
+#define PMT_XA_LIMIT                   XA_LIMIT(PMT_XA_START, PMT_XA_MAX)
 
 static DEFINE_IDA(intel_vsec_ida);
 static DEFINE_IDA(intel_vsec_sdsi_ida);
+static DEFINE_XARRAY_ALLOC(auxdev_array);
 
 /**
  * struct intel_vsec_header - Common fields of Intel VSEC and DVSEC registers.
@@ -132,7 +137,7 @@ static int intel_vsec_add_aux(struct pci_dev *pdev, struct intel_vsec_device *in
                              const char *name)
 {
        struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
-       int ret;
+       int ret, id;
 
        ret = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
        if (ret < 0) {
@@ -159,7 +164,18 @@ static int intel_vsec_add_aux(struct pci_dev *pdev, struct intel_vsec_device *in
                return ret;
        }
 
-       return devm_add_action_or_reset(&pdev->dev, intel_vsec_remove_aux, auxdev);
+       ret = devm_add_action_or_reset(&pdev->dev, intel_vsec_remove_aux,
+                                      auxdev);
+       if (ret < 0)
+               return ret;
+
+       /* Add auxdev to list */
+       ret = xa_alloc(&auxdev_array, &id, intel_vsec_dev, PMT_XA_LIMIT,
+                      GFP_KERNEL);
+       if (ret)
+               return ret;
+
+       return 0;
 }
 
 static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *header,
@@ -345,6 +361,7 @@ static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id
        if (ret)
                return ret;
 
+       pci_save_state(pdev);
        info = (struct intel_vsec_platform_info *)id->driver_data;
        if (!info)
                return -EINVAL;
@@ -406,10 +423,71 @@ static const struct pci_device_id intel_vsec_pci_ids[] = {
 };
 MODULE_DEVICE_TABLE(pci, intel_vsec_pci_ids);
 
+static pci_ers_result_t intel_vsec_pci_error_detected(struct pci_dev *pdev,
+                                                     pci_channel_state_t state)
+{
+       pci_channel_state_t status = PCI_ERS_RESULT_NEED_RESET;
+
+       dev_info(&pdev->dev, "PCI error detected, state %d", state);
+
+       if (state == pci_channel_io_perm_failure)
+               status = PCI_ERS_RESULT_DISCONNECT;
+       else
+               pci_disable_device(pdev);
+
+       return status;
+}
+
+static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
+{
+       struct intel_vsec_device *intel_vsec_dev;
+       pci_channel_state_t status = PCI_ERS_RESULT_DISCONNECT;
+       const struct pci_device_id *pci_dev_id;
+       unsigned long index;
+
+       dev_info(&pdev->dev, "Resetting PCI slot\n");
+
+       msleep(2000);
+       if (pci_enable_device(pdev)) {
+               dev_info(&pdev->dev,
+                        "Failed to re-enable PCI device after reset.\n");
+               goto out;
+       }
+
+       status =  PCI_ERS_RESULT_RECOVERED;
+
+       xa_for_each(&auxdev_array, index, intel_vsec_dev) {
+               /* check if pdev doesn't match */
+               if (pdev != intel_vsec_dev->pcidev)
+                       continue;
+               devm_release_action(&pdev->dev, intel_vsec_remove_aux,
+                                   &intel_vsec_dev->auxdev);
+       }
+       pci_disable_device(pdev);
+       pci_restore_state(pdev);
+       pci_dev_id = pci_match_id(intel_vsec_pci_ids, pdev);
+       intel_vsec_pci_probe(pdev, pci_dev_id);
+
+out:
+       return status;
+}
+
+static void intel_vsec_pci_resume(struct pci_dev *pdev)
+{
+       dev_info(&pdev->dev, "Done resuming PCI device\n");
+}
+
+const struct pci_error_handlers intel_vsec_pci_err_handlers = {
+       .error_detected = intel_vsec_pci_error_detected,
+       .slot_reset = intel_vsec_pci_slot_reset,
+       .resume = intel_vsec_pci_resume,
+};
+
 static struct pci_driver intel_vsec_pci_driver = {
        .name = "intel_vsec",
        .id_table = intel_vsec_pci_ids,
        .probe = intel_vsec_pci_probe,
+       .err_handler = &intel_vsec_pci_err_handlers,
 };
 module_pci_driver(intel_vsec_pci_driver);