1 files changed, 106 insertions, 32 deletions

diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index dbe95ec5917e..d930416d4c90 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -16,6 +16,7 @@
 #include <asm/sclp.h>
 
 #include "pci_bus.h"
+#include "pci_report.h"
 
 /* Content Code Description for PCI Function Error */
 struct zpci_ccdf_err {
@@ -53,6 +54,7 @@ static inline bool ers_result_indicates_abort(pci_ers_result_t ers_res)
 	case PCI_ERS_RESULT_CAN_RECOVER:
 	case PCI_ERS_RESULT_RECOVERED:
 	case PCI_ERS_RESULT_NEED_RESET:
+	case PCI_ERS_RESULT_NONE:
 		return false;
 	default:
 		return true;
@@ -77,10 +79,6 @@ static bool is_driver_supported(struct pci_driver *driver)
 		return false;
 	if (!driver->err_handler->error_detected)
 		return false;
-	if (!driver->err_handler->slot_reset)
-		return false;
-	if (!driver->err_handler->resume)
-		return false;
 	return true;
 }
 
@@ -105,6 +103,10 @@ static pci_ers_result_t zpci_event_do_error_state_clear(struct pci_dev *pdev,
 	struct zpci_dev *zdev = to_zpci(pdev);
 	int rc;
 
+	/* The underlying device may have been disabled by the event */
+	if (!zdev_enabled(zdev))
+		return PCI_ERS_RESULT_NEED_RESET;
+
 	pr_info("%s: Unblocking device access for examination\n", pci_name(pdev));
 	rc = zpci_reset_load_store_blocked(zdev);
 	if (rc) {
@@ -113,16 +115,18 @@ static pci_ers_result_t zpci_event_do_error_state_clear(struct pci_dev *pdev,
 		return PCI_ERS_RESULT_NEED_RESET;
 	}
 
-	if (driver->err_handler->mmio_enabled) {
+	if (driver->err_handler->mmio_enabled)
 		ers_res = driver->err_handler->mmio_enabled(pdev);
-		if (ers_result_indicates_abort(ers_res)) {
-			pr_info("%s: Automatic recovery failed after MMIO re-enable\n",
-				pci_name(pdev));
-			return ers_res;
-		} else if (ers_res == PCI_ERS_RESULT_NEED_RESET) {
-			pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
-			return ers_res;
-		}
+	else
+		ers_res = PCI_ERS_RESULT_NONE;
+
+	if (ers_result_indicates_abort(ers_res)) {
+		pr_info("%s: Automatic recovery failed after MMIO re-enable\n",
+			pci_name(pdev));
+		return ers_res;
+	} else if (ers_res == PCI_ERS_RESULT_NEED_RESET) {
+		pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
+		return ers_res;
 	}
 
 	pr_debug("%s: Unblocking DMA\n", pci_name(pdev));
@@ -149,7 +153,12 @@ static pci_ers_result_t zpci_event_do_reset(struct pci_dev *pdev,
 		return ers_res;
 	}
 	pdev->error_state = pci_channel_io_normal;
-	ers_res = driver->err_handler->slot_reset(pdev);
+
+	if (driver->err_handler->slot_reset)
+		ers_res = driver->err_handler->slot_reset(pdev);
+	else
+		ers_res = PCI_ERS_RESULT_NONE;
+
 	if (ers_result_indicates_abort(ers_res)) {
 		pr_info("%s: Automatic recovery failed after slot reset\n", pci_name(pdev));
 		return ers_res;
@@ -169,6 +178,8 @@ static pci_ers_result_t zpci_event_do_reset(struct pci_dev *pdev,
 static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
 {
 	pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
+	struct zpci_dev *zdev = to_zpci(pdev);
+	char *status_str = "success";
 	struct pci_driver *driver;
 
 	/*
@@ -186,37 +197,56 @@ static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
 	if (is_passed_through(pdev)) {
 		pr_info("%s: Cannot be recovered in the host because it is a pass-through device\n",
 			pci_name(pdev));
+		status_str = "failed (pass-through)";
 		goto out_unlock;
 	}
 
 	driver = to_pci_driver(pdev->dev.driver);
 	if (!is_driver_supported(driver)) {
-		if (!driver)
+		if (!driver) {
 			pr_info("%s: Cannot be recovered because no driver is bound to the device\n",
 				pci_name(pdev));
-		else
+			status_str = "failed (no driver)";
+		} else {
 			pr_info("%s: The %s driver bound to the device does not support error recovery\n",
 				pci_name(pdev),
 				driver->name);
+			status_str = "failed (no driver support)";
+		}
 		goto out_unlock;
 	}
 
 	ers_res = zpci_event_notify_error_detected(pdev, driver);
-	if (ers_result_indicates_abort(ers_res))
+	if (ers_result_indicates_abort(ers_res)) {
+		status_str = "failed (abort on detection)";
 		goto out_unlock;
+	}
 
-	if (ers_res == PCI_ERS_RESULT_CAN_RECOVER) {
+	if (ers_res != PCI_ERS_RESULT_NEED_RESET) {
 		ers_res = zpci_event_do_error_state_clear(pdev, driver);
-		if (ers_result_indicates_abort(ers_res))
+		if (ers_result_indicates_abort(ers_res)) {
+			status_str = "failed (abort on MMIO enable)";
 			goto out_unlock;
+		}
 	}
 
 	if (ers_res == PCI_ERS_RESULT_NEED_RESET)
 		ers_res = zpci_event_do_reset(pdev, driver);
 
+	/*
+	 * ers_res can be PCI_ERS_RESULT_NONE either because the driver
+	 * decided to return it, indicating that it abstains from voting
+	 * on how to recover, or because it didn't implement the callback.
+	 * Both cases assume, that if there is nothing else causing a
+	 * disconnect, we recovered successfully.
+	 */
+	if (ers_res == PCI_ERS_RESULT_NONE)
+		ers_res = PCI_ERS_RESULT_RECOVERED;
+
 	if (ers_res != PCI_ERS_RESULT_RECOVERED) {
 		pr_err("%s: Automatic recovery failed; operator intervention is required\n",
 		       pci_name(pdev));
+		status_str = "failed (driver can't recover)";
 		goto out_unlock;
 	}
 
@@ -225,6 +255,7 @@ static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
 		driver->err_handler->resume(pdev);
 out_unlock:
 	pci_dev_unlock(pdev);
+	zpci_report_status(zdev, "recovery", status_str);
 
 	return ers_res;
 }
@@ -260,6 +291,8 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
 	struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
 	struct pci_dev *pdev = NULL;
 	pci_ers_result_t ers_res;
+	u32 fh = 0;
+	int rc;
 
 	zpci_dbg(3, "err fid:%x, fh:%x, pec:%x\n",
 		 ccdf->fid, ccdf->fh, ccdf->pec);
@@ -268,6 +301,15 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
 
 	if (zdev) {
 		mutex_lock(&zdev->state_lock);
+		rc = clp_refresh_fh(zdev->fid, &fh);
+		if (rc)
+			goto no_pdev;
+		if (!fh || ccdf->fh != fh) {
+			/* Ignore events with stale handles */
+			zpci_dbg(3, "err fid:%x, fh:%x (stale %x)\n",
+				 ccdf->fid, fh, ccdf->fh);
+			goto no_pdev;
+		}
 		zpci_update_fh(zdev, ccdf->fh);
 		if (zdev->zbus->bus)
 			pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
@@ -280,18 +322,19 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
 		goto no_pdev;
 
 	switch (ccdf->pec) {
-	case 0x003a: /* Service Action or Error Recovery Successful */
+	case 0x002a: /* Error event concerns FMB */
+	case 0x002b:
+	case 0x002c:
+		break;
+	case 0x0040: /* Service Action or Error Recovery Failed */
+	case 0x003b:
+		zpci_event_io_failure(pdev, pci_channel_io_perm_failure);
+		break;
+	default: /* PCI function left in the error state attempt to recover */
 		ers_res = zpci_event_attempt_error_recovery(pdev);
 		if (ers_res != PCI_ERS_RESULT_RECOVERED)
 			zpci_event_io_failure(pdev, pci_channel_io_perm_failure);
 		break;
-	default:
-		/*
-		 * Mark as frozen not permanently failed because the device
-		 * could be subsequently recovered by the platform.
-		 */
-		zpci_event_io_failure(pdev, pci_channel_io_frozen);
-		break;
 	}
 	pci_dev_put(pdev);
 no_pdev:
@@ -321,6 +364,22 @@ static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
 	zdev->state = ZPCI_FN_STATE_STANDBY;
 }
 
+static void zpci_event_reappear(struct zpci_dev *zdev)
+{
+	lockdep_assert_held(&zdev->state_lock);
+	/*
+	 * The zdev is in the reserved state. This means that it was presumed to
+	 * go away but there are still undropped references. Now, the platform
+	 * announced its availability again. Bring back the lingering zdev
+	 * to standby. This is safe because we hold a temporary reference
+	 * now so that it won't go away. Account for the re-appearance of the
+	 * underlying device by incrementing the reference count.
+	 */
+	zdev->state = ZPCI_FN_STATE_STANDBY;
+	zpci_zdev_get(zdev);
+	zpci_dbg(1, "rea fid:%x, fh:%x\n", zdev->fid, zdev->fh);
+}
+
 static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 {
 	struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
@@ -339,19 +398,34 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 			zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED);
 			if (IS_ERR(zdev))
 				break;
+			if (zpci_add_device(zdev)) {
+				kfree(zdev);
+				break;
+			}
 		} else {
+			if (zdev->state == ZPCI_FN_STATE_RESERVED)
+				zpci_event_reappear(zdev);
 			/* the configuration request may be stale */
-			if (zdev->state != ZPCI_FN_STATE_STANDBY)
+			else if (zdev->state != ZPCI_FN_STATE_STANDBY)
 				break;
 			zdev->state = ZPCI_FN_STATE_CONFIGURED;
 		}
 		zpci_scan_configured_device(zdev, ccdf->fh);
 		break;
 	case 0x0302: /* Reserved -> Standby */
-		if (!zdev)
-			zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
-		else
+		if (!zdev) {
+			zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
+			if (IS_ERR(zdev))
+				break;
+			if (zpci_add_device(zdev)) {
+				kfree(zdev);
+				break;
+			}
+		} else {
+			if (zdev->state == ZPCI_FN_STATE_RESERVED)
+				zpci_event_reappear(zdev);
 			zpci_update_fh(zdev, ccdf->fh);
+		}
 		break;
 	case 0x0303: /* Deconfiguration requested */
 		if (zdev) {
@@ -380,7 +454,7 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 		break;
 	case 0x0306: /* 0x308 or 0x302 for multiple devices */
 		zpci_remove_reserved_devices();
-		clp_scan_pci_devices();
+		zpci_scan_devices();
 		break;
 	case 0x0308: /* Standby -> Reserved */
 		if (!zdev)