IB/mthca: Recover from catastrophic errors

Trigger device remove and then add when a catastrophic error is
detected in hardware.  This, in turn, will cause a device reset, which
we hope will recover from the catastrophic condition.

Since this might interefere with debugging the root cause, add a
module option to suppress this behaviour.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 136 insertions, 21 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_catas.c b/drivers/infiniband/hw/mthca/mthca_catas.c
index c3bec7490f52..cd044ea2dfa4 100644
--- a/drivers/infiniband/hw/mthca/mthca_catas.c
+++ b/drivers/infiniband/hw/mthca/mthca_catas.c
@@ -34,6 +34,7 @@
 
 #include <linux/jiffies.h>
 #include <linux/timer.h>
+#include <linux/workqueue.h>
 
 #include "mthca_dev.h"
 
@@ -48,9 +49,41 @@ enum {
 
 static DEFINE_SPINLOCK(catas_lock);
 
+static LIST_HEAD(catas_list);
+static struct workqueue_struct *catas_wq;
+static struct work_struct catas_work;
+
+static int catas_reset_disable;
+module_param_named(catas_reset_disable, catas_reset_disable, int, 0644);
+MODULE_PARM_DESC(catas_reset_disable, "disable reset on catastrophic event if nonzero");
+
+static void catas_reset(void *work_ptr)
+{
+        struct mthca_dev *dev, *tmpdev;
+        LIST_HEAD(tlist);
+        int ret;
+
+        mutex_lock(&mthca_device_mutex);
+
+        spin_lock_irq(&catas_lock);
+        list_splice_init(&catas_list, &tlist);
+        spin_unlock_irq(&catas_lock);
+
+        list_for_each_entry_safe(dev, tmpdev, &tlist, catas_err.list) {
+                ret = __mthca_restart_one(dev->pdev);
+                if (ret)
+                        mthca_err(dev, "Reset failed (%d)\n", ret);
+                else
+                        mthca_dbg(dev, "Reset succeeded\n");
+        }
+
+        mutex_unlock(&mthca_device_mutex);
+}
+
 static void handle_catas(struct mthca_dev *dev)
 {
         struct ib_event event;
+        unsigned long flags;
         const char *type;
         int i;
 
@@ -82,6 +115,14 @@ static void handle_catas(struct mthca_dev *dev)
         for (i = 0; i < dev->catas_err.size; ++i)
                 mthca_err(dev, "  buf[%02x]: %08x\n",
                           i, swab32(readl(dev->catas_err.map + i)));
+
+        if (catas_reset_disable)
+                return;
+
+        spin_lock_irqsave(&catas_lock, flags);
+        list_add(&dev->catas_err.list, &catas_list);
+        queue_work(catas_wq, &catas_work);
+        spin_unlock_irqrestore(&catas_lock, flags);
 }
 
 static void poll_catas(unsigned long dev_ptr)
@@ -135,6 +176,7 @@ void mthca_start_catas_poll(struct mthca_dev *dev)
         dev->catas_err.timer.data     = (unsigned long) dev;
         dev->catas_err.timer.function = poll_catas;
         dev->catas_err.timer.expires  = jiffies + MTHCA_CATAS_POLL_INTERVAL;
+        INIT_LIST_HEAD(&dev->catas_err.list);
         add_timer(&dev->catas_err.timer);
 }
 
@@ -153,4 +195,24 @@ void mthca_stop_catas_poll(struct mthca_dev *dev)
                                     dev->catas_err.addr),
                                    dev->catas_err.size * 4);
         }
+
+        spin_lock_irq(&catas_lock);
+        list_del(&dev->catas_err.list);
+        spin_unlock_irq(&catas_lock);
+}
+
+int __init mthca_catas_init(void)
+{
+        INIT_WORK(&catas_work, catas_reset, NULL);
+
+        catas_wq = create_singlethread_workqueue("mthca_catas");
+        if (!catas_wq)
+                return -ENOMEM;
+
+        return 0;
+}
+
+void mthca_catas_cleanup(void)
+{
+        destroy_workqueue(catas_wq);
 }
diff --git a/drivers/infiniband/hw/mthca/mthca_dev.h b/drivers/infiniband/hw/mthca/mthca_dev.h
index 33bd0b8bfd13..fe5cecf70fed 100644
--- a/drivers/infiniband/hw/mthca/mthca_dev.h
+++ b/drivers/infiniband/hw/mthca/mthca_dev.h
@@ -45,6 +45,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/timer.h>
 #include <linux/mutex.h>
+#include <linux/list.h>
 
 #include <asm/semaphore.h>
 
@@ -283,8 +284,11 @@ struct mthca_catas_err {
         unsigned long           stop;
         u32                     size;
         struct timer_list       timer;
+        struct list_head        list;
 };
 
+extern struct mutex mthca_device_mutex;
+
 struct mthca_dev {
         struct ib_device  ib_dev;
         struct pci_dev   *pdev;
@@ -450,6 +454,9 @@ void mthca_unregister_device(struct mthca_dev *dev);
 
 void mthca_start_catas_poll(struct mthca_dev *dev);
 void mthca_stop_catas_poll(struct mthca_dev *dev);
+int __mthca_restart_one(struct pci_dev *pdev);
+int mthca_catas_init(void);
+void mthca_catas_cleanup(void);
 
 int mthca_uar_alloc(struct mthca_dev *dev, struct mthca_uar *uar);
 void mthca_uar_free(struct mthca_dev *dev, struct mthca_uar *uar);
diff --git a/drivers/infiniband/hw/mthca/mthca_main.c b/drivers/infiniband/hw/mthca/mthca_main.c
index 7b82c1907f04..47ea02148368 100644
--- a/drivers/infiniband/hw/mthca/mthca_main.c
+++ b/drivers/infiniband/hw/mthca/mthca_main.c
@@ -80,6 +80,8 @@ static int tune_pci = 0;
 module_param(tune_pci, int, 0444);
 MODULE_PARM_DESC(tune_pci, "increase PCI burst from the default set by BIOS if nonzero");
 
+struct mutex mthca_device_mutex;
+
 static const char mthca_version[] __devinitdata =
         DRV_NAME ": Mellanox InfiniBand HCA driver v"
         DRV_VERSION " (" DRV_RELDATE ")\n";
@@ -978,28 +980,15 @@ static struct {
                                         MTHCA_FLAG_SINAI_OPT }
 };
 
-static int __devinit mthca_init_one(struct pci_dev *pdev,
-                                    const struct pci_device_id *id)
+static int __mthca_init_one(struct pci_dev *pdev, int hca_type)
 {
-        static int mthca_version_printed = 0;
         int ddr_hidden = 0;
         int err;
         struct mthca_dev *mdev;
 
-        if (!mthca_version_printed) {
-                printk(KERN_INFO "%s", mthca_version);
-                ++mthca_version_printed;
-        }
-
         printk(KERN_INFO PFX "Initializing %s\n",
                pci_name(pdev));
 
-        if (id->driver_data >= ARRAY_SIZE(mthca_hca_table)) {
-                printk(KERN_ERR PFX "%s has invalid driver data %lx\n",
-                       pci_name(pdev), id->driver_data);
-                return -ENODEV;
-        }
-
         err = pci_enable_device(pdev);
         if (err) {
                 dev_err(&pdev->dev, "Cannot enable PCI device, "
@@ -1065,7 +1054,7 @@ static int __devinit mthca_init_one(struct pci_dev *pdev,
 
         mdev->pdev = pdev;
 
-        mdev->mthca_flags = mthca_hca_table[id->driver_data].flags;
+        mdev->mthca_flags = mthca_hca_table[hca_type].flags;
         if (ddr_hidden)
                 mdev->mthca_flags |= MTHCA_FLAG_DDR_HIDDEN;
 
@@ -1099,13 +1088,13 @@ static int __devinit mthca_init_one(struct pci_dev *pdev,
         if (err)
                 goto err_cmd;
 
-        if (mdev->fw_ver < mthca_hca_table[id->driver_data].latest_fw) {
+        if (mdev->fw_ver < mthca_hca_table[hca_type].latest_fw) {
                 mthca_warn(mdev, "HCA FW version %d.%d.%d is old (%d.%d.%d is current).\n",
                            (int) (mdev->fw_ver >> 32), (int) (mdev->fw_ver >> 16) & 0xffff,
                            (int) (mdev->fw_ver & 0xffff),
-                           (int) (mthca_hca_table[id->driver_data].latest_fw >> 32),
-                           (int) (mthca_hca_table[id->driver_data].latest_fw >> 16) & 0xffff,
-                           (int) (mthca_hca_table[id->driver_data].latest_fw & 0xffff));
+                           (int) (mthca_hca_table[hca_type].latest_fw >> 32),
+                           (int) (mthca_hca_table[hca_type].latest_fw >> 16) & 0xffff,
+                           (int) (mthca_hca_table[hca_type].latest_fw & 0xffff));
                 mthca_warn(mdev, "If you have problems, try updating your HCA FW.\n");
         }
 
@@ -1122,6 +1111,7 @@ static int __devinit mthca_init_one(struct pci_dev *pdev,
                 goto err_unregister;
 
         pci_set_drvdata(pdev, mdev);
+        mdev->hca_type = hca_type;
 
         return 0;
 
@@ -1166,7 +1156,7 @@ err_disable_pdev:
         return err;
 }
 
-static void __devexit mthca_remove_one(struct pci_dev *pdev)
+static void __mthca_remove_one(struct pci_dev *pdev)
 {
         struct mthca_dev *mdev = pci_get_drvdata(pdev);
         u8 status;
@@ -1211,6 +1201,51 @@ static void __devexit mthca_remove_one(struct pci_dev *pdev)
         }
 }
 
+int __mthca_restart_one(struct pci_dev *pdev)
+{
+        struct mthca_dev *mdev;
+
+        mdev = pci_get_drvdata(pdev);
+        if (!mdev)
+                return -ENODEV;
+        __mthca_remove_one(pdev);
+        return __mthca_init_one(pdev, mdev->hca_type);
+}
+
+static int __devinit mthca_init_one(struct pci_dev *pdev,
+                             const struct pci_device_id *id)
+{
+        static int mthca_version_printed = 0;
+        int ret;
+
+        mutex_lock(&mthca_device_mutex);
+
+        if (!mthca_version_printed) {
+                printk(KERN_INFO "%s", mthca_version);
+                ++mthca_version_printed;
+        }
+
+        if (id->driver_data >= ARRAY_SIZE(mthca_hca_table)) {
+                printk(KERN_ERR PFX "%s has invalid driver data %lx\n",
+                       pci_name(pdev), id->driver_data);
+                mutex_unlock(&mthca_device_mutex);
+                return -ENODEV;
+        }
+
+        ret = __mthca_init_one(pdev, id->driver_data);
+
+        mutex_unlock(&mthca_device_mutex);
+
+        return ret;
+}
+
+static void __devexit mthca_remove_one(struct pci_dev *pdev)
+{
+        mutex_lock(&mthca_device_mutex);
+        __mthca_remove_one(pdev);
+        mutex_unlock(&mthca_device_mutex);
+}
+
 static struct pci_device_id mthca_pci_table[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_MELLANOX, PCI_DEVICE_ID_MELLANOX_TAVOR),
           .driver_data = TAVOR },
@@ -1248,13 +1283,24 @@ static int __init mthca_init(void)
 {
         int ret;
 
+        mutex_init(&mthca_device_mutex);
+        ret = mthca_catas_init();
+        if (ret)
+                return ret;
+
         ret = pci_register_driver(&mthca_driver);
-        return ret < 0 ? ret : 0;
+        if (ret < 0) {
+                mthca_catas_cleanup();
+                return ret;
+        }
+
+        return 0;
 }
 
 static void __exit mthca_cleanup(void)
 {
         pci_unregister_driver(&mthca_driver);
+        mthca_catas_cleanup();
 }
 
 module_init(mthca_init);