[SCSI] hpsa: use workqueue instead of kernel thread for lockup detection

Much simpler and avoids races starting/stopping the thread.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 91e2d83..f929875 100644 (file)
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -168,10 +168,6 @@ static struct board_type products[] = {
 
 static int number_of_controllers;
 
-static struct list_head hpsa_ctlr_list = LIST_HEAD_INIT(hpsa_ctlr_list);
-static spinlock_t lockup_detector_lock;
-static struct task_struct *hpsa_lockup_detector;
-
 static irqreturn_t do_hpsa_intr_intx(int irq, void *dev_id);
 static irqreturn_t do_hpsa_intr_msi(int irq, void *dev_id);
 static int hpsa_ioctl(struct scsi_device *dev, int cmd, void *arg);
@@ -4716,16 +4712,6 @@ static void hpsa_undo_allocations_after_kdump_soft_reset(struct ctlr_info *h)
        kfree(h);
 }
 
-static void remove_ctlr_from_lockup_detector_list(struct ctlr_info *h)
-{
-       assert_spin_locked(&lockup_detector_lock);
-       if (!hpsa_lockup_detector)
-               return;
-       if (h->lockup_detected)
-               return; /* already stopped the lockup detector */
-       list_del(&h->lockup_list);
-}
-
 /* Called when controller lockup detected. */
 static void fail_all_cmds_on_list(struct ctlr_info *h, struct list_head *list)
 {
@@ -4744,8 +4730,6 @@ static void controller_lockup_detected(struct ctlr_info *h)
 {
        unsigned long flags;
 
-       assert_spin_locked(&lockup_detector_lock);
-       remove_ctlr_from_lockup_detector_list(h);
        h->access.set_intr_mask(h, HPSA_INTR_OFF);
        spin_lock_irqsave(&h->lock, flags);
        h->lockup_detected = readl(h->vaddr + SA5_SCRATCHPAD_OFFSET);
@@ -4765,7 +4749,6 @@ static void detect_controller_lockup(struct ctlr_info *h)
        u32 heartbeat;
        unsigned long flags;
 
-       assert_spin_locked(&lockup_detector_lock);
        now = get_jiffies_64();
        /* If we've received an interrupt recently, we're ok. */
        if (time_after64(h->last_intr_timestamp +
@@ -4795,68 +4778,22 @@ static void detect_controller_lockup(struct ctlr_info *h)
        h->last_heartbeat_timestamp = now;
 }
 
-static int detect_controller_lockup_thread(void *notused)
-{
-       struct ctlr_info *h;
-       unsigned long flags;
-
-       while (1) {
-               struct list_head *this, *tmp;
-
-               schedule_timeout_interruptible(HEARTBEAT_SAMPLE_INTERVAL);
-               if (kthread_should_stop())
-                       break;
-               spin_lock_irqsave(&lockup_detector_lock, flags);
-               list_for_each_safe(this, tmp, &hpsa_ctlr_list) {
-                       h = list_entry(this, struct ctlr_info, lockup_list);
-                       detect_controller_lockup(h);
-               }
-               spin_unlock_irqrestore(&lockup_detector_lock, flags);
-       }
-       return 0;
-}
-
-static void add_ctlr_to_lockup_detector_list(struct ctlr_info *h)
+static void hpsa_monitor_ctlr_worker(struct work_struct *work)
 {
        unsigned long flags;
-
-       h->heartbeat_sample_interval = HEARTBEAT_SAMPLE_INTERVAL;
-       spin_lock_irqsave(&lockup_detector_lock, flags);
-       list_add_tail(&h->lockup_list, &hpsa_ctlr_list);
-       spin_unlock_irqrestore(&lockup_detector_lock, flags);
-}
-
-static void start_controller_lockup_detector(struct ctlr_info *h)
-{
-       /* Start the lockup detector thread if not already started */
-       if (!hpsa_lockup_detector) {
-               spin_lock_init(&lockup_detector_lock);
-               hpsa_lockup_detector =
-                       kthread_run(detect_controller_lockup_thread,
-                                               NULL, HPSA);
-       }
-       if (!hpsa_lockup_detector) {
-               dev_warn(&h->pdev->dev,
-                       "Could not start lockup detector thread\n");
+       struct ctlr_info *h = container_of(to_delayed_work(work),
+                                       struct ctlr_info, monitor_ctlr_work);
+       detect_controller_lockup(h);
+       if (h->lockup_detected)
+               return;
+       spin_lock_irqsave(&h->lock, flags);
+       if (h->remove_in_progress) {
+               spin_unlock_irqrestore(&h->lock, flags);
                return;
        }
-       add_ctlr_to_lockup_detector_list(h);
-}
-
-static void stop_controller_lockup_detector(struct ctlr_info *h)
-{
-       unsigned long flags;
-
-       spin_lock_irqsave(&lockup_detector_lock, flags);
-       remove_ctlr_from_lockup_detector_list(h);
-       /* If the list of ctlr's to monitor is empty, stop the thread */
-       if (list_empty(&hpsa_ctlr_list)) {
-               spin_unlock_irqrestore(&lockup_detector_lock, flags);
-               kthread_stop(hpsa_lockup_detector);
-               spin_lock_irqsave(&lockup_detector_lock, flags);
-               hpsa_lockup_detector = NULL;
-       }
-       spin_unlock_irqrestore(&lockup_detector_lock, flags);
+       schedule_delayed_work(&h->monitor_ctlr_work,
+                               h->heartbeat_sample_interval);
+       spin_unlock_irqrestore(&h->lock, flags);
 }
 
 static int hpsa_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
@@ -5004,7 +4941,12 @@ reinit_after_soft_reset:
 
        hpsa_hba_inquiry(h);
        hpsa_register_scsi(h);  /* hook ourselves into SCSI subsystem */
-       start_controller_lockup_detector(h);
+
+       /* Monitor the controller for firmware lockups */
+       h->heartbeat_sample_interval = HEARTBEAT_SAMPLE_INTERVAL;
+       INIT_DELAYED_WORK(&h->monitor_ctlr_work, hpsa_monitor_ctlr_worker);
+       schedule_delayed_work(&h->monitor_ctlr_work,
+                               h->heartbeat_sample_interval);
        return 0;
 
 clean4:
@@ -5079,13 +5021,20 @@ static void hpsa_free_device_info(struct ctlr_info *h)
 static void hpsa_remove_one(struct pci_dev *pdev)
 {
        struct ctlr_info *h;
+       unsigned long flags;
 
        if (pci_get_drvdata(pdev) == NULL) {
                dev_err(&pdev->dev, "unable to remove device\n");
                return;
        }
        h = pci_get_drvdata(pdev);
-       stop_controller_lockup_detector(h);
+
+       /* Get rid of any controller monitoring work items */
+       spin_lock_irqsave(&h->lock, flags);
+       h->remove_in_progress = 1;
+       cancel_delayed_work(&h->monitor_ctlr_work);
+       spin_unlock_irqrestore(&h->lock, flags);
+
        hpsa_unregister_scsi(h);        /* unhook from SCSI subsystem */
        hpsa_shutdown(pdev);
        iounmap(h->vaddr);

diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 5f3f72f..01c3283 100644 (file)
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -135,7 +135,8 @@ struct ctlr_info {
        u32 heartbeat_sample_interval;
        atomic_t firmware_flash_in_progress;
        u32 lockup_detected;
-       struct list_head lockup_list;
+       struct delayed_work monitor_ctlr_work;
+       int remove_in_progress;
        u32 fifo_recently_full;
        /* Address of h->q[x] is passed to intr handler to know which queue */
        u8 q[MAX_REPLY_QUEUES];