[SCSI] mpt2sas: RESCAN Barrier work is added in case of HBA reset.

Add the cancel_pending_work flag from the fw_event_work structure, and then to
set the flag during host reset, check the flag later from work threads
context and if cancel_pending_work_flag is set ingore those events.

Now Rescan after host reset is changed.
Added special task MPT2SAS_RESCAN_AFTER_HOST_RESET. This task will be queued
at the time of HBA reset. this task is treated as barrier. All work after
MPT2SAS_RESCAN_AFTER_HOST_RESET will be treated as new work and will be
server by callback handle. If host_recovery is going on while running RESCAN
task, it will wait for shos_recovery_done completion which will be called
from HBA reset DONE context.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Reviewed-by: Eric Moore <eric.moore@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

3 files changed, 79 insertions, 69 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index 88e6eebc3159..da4bfbf95a7a 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -3607,6 +3607,8 @@ mpt2sas_base_attach(struct MPT2SAS_ADAPTER *ioc)
         ioc->ctl_cmds.status = MPT2_CMD_NOT_USED;
         mutex_init(&ioc->ctl_cmds.mutex);
 
+        init_completion(&ioc->shost_recovery_done);
+
         for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                 ioc->event_masks[i] = -1;
 
@@ -3811,9 +3813,8 @@ mpt2sas_base_hard_reset_handler(struct MPT2SAS_ADAPTER *ioc, int sleep_flag,
 
         spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
         ioc->shost_recovery = 0;
+        complete(&ioc->shost_recovery_done);
         spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
 
-        if (!r)
-                _base_reset_handler(ioc, MPT2_IOC_RUNNING);
         return r;
 }
diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.h b/drivers/scsi/mpt2sas/mpt2sas_base.h
index e18b0544c38f..a5ec09f7c90a 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.h
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.h
@@ -119,7 +119,6 @@
 #define MPT2_IOC_PRE_RESET              1 /* prior to host reset */
 #define MPT2_IOC_AFTER_RESET            2 /* just after host reset */
 #define MPT2_IOC_DONE_RESET             3 /* links re-initialized */
-#define MPT2_IOC_RUNNING                4 /* shost running */
 
 /*
  * logging format
@@ -603,7 +602,6 @@ struct MPT2SAS_ADAPTER {
         /* fw event handler */
         char            firmware_event_name[20];
         struct workqueue_struct *firmware_event_thread;
-        u8              fw_events_off;
         spinlock_t      fw_event_lock;
         struct list_head fw_event_list;
 
@@ -611,6 +609,7 @@ struct MPT2SAS_ADAPTER {
         int             aen_event_read_flag;
         u8              broadcast_aen_busy;
         u8              shost_recovery;
+        struct completion       shost_recovery_done;
         spinlock_t      ioc_reset_in_progress_lock;
         u8              ioc_link_reset_in_progress;
         u8              ignore_loginfos;
diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index aa67b757bf23..6f121a904d05 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -109,14 +109,16 @@ struct sense_info {
 };
 
 
+#define MPT2SAS_RESCAN_AFTER_HOST_RESET (0xFFFF)
+
 /**
  * struct fw_event_work - firmware event struct
  * @list: link list framework
  * @work: work object (ioc->fault_reset_work_q)
+ * @cancel_pending_work: flag set during reset handling
  * @ioc: per adapter object
  * @VF_ID: virtual function id
  * @VP_ID: virtual port id
- * @host_reset_handling: handling events during host reset
  * @ignore: flag meaning this event has been marked to ignore
  * @event: firmware event MPI2_EVENT_XXX defined in mpt2_ioc.h
  * @event_data: reply event data payload follows
@@ -125,11 +127,11 @@ struct sense_info {
  */
 struct fw_event_work {
         struct list_head        list;
-        struct work_struct      work;
+        u8                      cancel_pending_work;
+        struct delayed_work     delayed_work;
         struct MPT2SAS_ADAPTER *ioc;
         u8                      VF_ID;
         u8                      VP_ID;
-        u8                      host_reset_handling;
         u8                      ignore;
         u16                     event;
         void                    *event_data;
@@ -2325,8 +2327,9 @@ _scsih_fw_event_add(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work *fw_event)
 
         spin_lock_irqsave(&ioc->fw_event_lock, flags);
         list_add_tail(&fw_event->list, &ioc->fw_event_list);
-        INIT_WORK(&fw_event->work, _firmware_event_work);
-        queue_work(ioc->firmware_event_thread, &fw_event->work);
+        INIT_DELAYED_WORK(&fw_event->delayed_work, _firmware_event_work);
+        queue_delayed_work(ioc->firmware_event_thread,
+            &fw_event->delayed_work, 0);
         spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
 }
 
@@ -2353,62 +2356,55 @@ _scsih_fw_event_free(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work
         spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
 }
 
+
 /**
- * _scsih_fw_event_add - requeue an event
+ * _scsih_queue_rescan - queue a topology rescan from user context
  * @ioc: per adapter object
- * @fw_event: object describing the event
- * Context: This function will acquire ioc->fw_event_lock.
  *
  * Return nothing.
  */
 static void
-_scsih_fw_event_requeue(struct MPT2SAS_ADAPTER *ioc, struct fw_event_work
-    *fw_event, unsigned long delay)
+_scsih_queue_rescan(struct MPT2SAS_ADAPTER *ioc)
 {
-        unsigned long flags;
-        if (ioc->firmware_event_thread == NULL)
-                return;
+        struct fw_event_work *fw_event;
 
-        spin_lock_irqsave(&ioc->fw_event_lock, flags);
-        queue_work(ioc->firmware_event_thread, &fw_event->work);
-        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
+        if (ioc->wait_for_port_enable_to_complete)
+                return;
+        fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
+        if (!fw_event)
+                return;
+        fw_event->event = MPT2SAS_RESCAN_AFTER_HOST_RESET;
+        fw_event->ioc = ioc;
+        _scsih_fw_event_add(ioc, fw_event);
 }
 
 /**
- * _scsih_fw_event_off - turn flag off preventing event handling
+ * _scsih_fw_event_cleanup_queue - cleanup event queue
  * @ioc: per adapter object
  *
- * Used to prevent handling of firmware events during adapter reset
- * driver unload.
+ * Walk the firmware event queue, either killing timers, or waiting
+ * for outstanding events to complete
  *
  * Return nothing.
  */
 static void
-_scsih_fw_event_off(struct MPT2SAS_ADAPTER *ioc)
+_scsih_fw_event_cleanup_queue(struct MPT2SAS_ADAPTER *ioc)
 {
-        unsigned long flags;
+        struct fw_event_work *fw_event, *next;
 
-        spin_lock_irqsave(&ioc->fw_event_lock, flags);
-        ioc->fw_events_off = 1;
-        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
+        if (list_empty(&ioc->fw_event_list) ||
+             !ioc->firmware_event_thread || in_interrupt())
+                return;
 
+        list_for_each_entry_safe(fw_event, next, &ioc->fw_event_list, list) {
+                if (cancel_delayed_work(&fw_event->delayed_work)) {
+                        _scsih_fw_event_free(ioc, fw_event);
+                        continue;
+                }
+                fw_event->cancel_pending_work = 1;
+        }
 }
 
-/**
- * _scsih_fw_event_on - turn flag on allowing firmware event handling
- * @ioc: per adapter object
- *
- * Returns nothing.
- */
-static void
-_scsih_fw_event_on(struct MPT2SAS_ADAPTER *ioc)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&ioc->fw_event_lock, flags);
-        ioc->fw_events_off = 0;
-        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
-}
 
 /**
  * _scsih_ublock_io_device - set the device state to SDEV_RUNNING
@@ -5694,13 +5690,13 @@ _scsih_search_responding_expanders(struct MPT2SAS_ADAPTER *ioc)
 }
 
 /**
- * _scsih_remove_unresponding_devices - removing unresponding devices
+ * _scsih_remove_unresponding_sas_devices - removing unresponding devices
  * @ioc: per adapter object
  *
  * Return nothing.
  */
 static void
-_scsih_remove_unresponding_devices(struct MPT2SAS_ADAPTER *ioc)
+_scsih_remove_unresponding_sas_devices(struct MPT2SAS_ADAPTER *ioc)
 {
         struct _sas_device *sas_device, *sas_device_next;
         struct _sas_node *sas_expander;
@@ -5774,31 +5770,28 @@ mpt2sas_scsih_reset_handler(struct MPT2SAS_ADAPTER *ioc, int reset_phase)
         case MPT2_IOC_PRE_RESET:
                 dtmprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s: "
                     "MPT2_IOC_PRE_RESET\n", ioc->name, __func__));
-                _scsih_fw_event_off(ioc);
                 break;
         case MPT2_IOC_AFTER_RESET:
                 dtmprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s: "
                     "MPT2_IOC_AFTER_RESET\n", ioc->name, __func__));
+                if (ioc->scsih_cmds.status & MPT2_CMD_PENDING) {
+                        ioc->scsih_cmds.status |= MPT2_CMD_RESET;
+                        mpt2sas_base_free_smid(ioc, ioc->scsih_cmds.smid);
+                        complete(&ioc->scsih_cmds.done);
+                }
                 if (ioc->tm_cmds.status & MPT2_CMD_PENDING) {
                         ioc->tm_cmds.status |= MPT2_CMD_RESET;
                         mpt2sas_base_free_smid(ioc, ioc->tm_cmds.smid);
                         complete(&ioc->tm_cmds.done);
                 }
-                _scsih_fw_event_on(ioc);
+                _scsih_fw_event_cleanup_queue(ioc);
                 _scsih_flush_running_cmds(ioc);
+                _scsih_queue_rescan(ioc);
                 break;
         case MPT2_IOC_DONE_RESET:
                 dtmprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s: "
                     "MPT2_IOC_DONE_RESET\n", ioc->name, __func__));
                 _scsih_sas_host_refresh(ioc);
-                _scsih_search_responding_sas_devices(ioc);
-                _scsih_search_responding_raid_devices(ioc);
-                _scsih_search_responding_expanders(ioc);
-                break;
-        case MPT2_IOC_RUNNING:
-                dtmprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s: "
-                    "MPT2_IOC_RUNNING\n", ioc->name, __func__));
-                _scsih_remove_unresponding_devices(ioc);
                 break;
         }
 }
@@ -5815,21 +5808,31 @@ static void
 _firmware_event_work(struct work_struct *work)
 {
         struct fw_event_work *fw_event = container_of(work,
-            struct fw_event_work, work);
+            struct fw_event_work, delayed_work.work);
         unsigned long flags;
         struct MPT2SAS_ADAPTER *ioc = fw_event->ioc;
 
         /* the queue is being flushed so ignore this event */
-        spin_lock_irqsave(&ioc->fw_event_lock, flags);
-        if (ioc->fw_events_off || ioc->remove_host) {
-                spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
+        if (ioc->remove_host || fw_event->cancel_pending_work) {
                 _scsih_fw_event_free(ioc, fw_event);
                 return;
         }
-        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
 
-        if (ioc->shost_recovery) {
-                _scsih_fw_event_requeue(ioc, fw_event, 1000);
+        if (fw_event->event == MPT2SAS_RESCAN_AFTER_HOST_RESET) {
+                _scsih_fw_event_free(ioc, fw_event);
+                spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
+                if (ioc->shost_recovery) {
+                        init_completion(&ioc->shost_recovery_done);
+                        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock,
+                            flags);
+                        wait_for_completion(&ioc->shost_recovery_done);
+                } else
+                        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock,
+                            flags);
+                _scsih_search_responding_sas_devices(ioc);
+                _scsih_search_responding_raid_devices(ioc);
+                _scsih_search_responding_expanders(ioc);
+                _scsih_remove_unresponding_sas_devices(ioc);
                 return;
         }
 
@@ -5891,16 +5894,11 @@ mpt2sas_scsih_event_callback(struct MPT2SAS_ADAPTER *ioc, u8 msix_index,
 {
         struct fw_event_work *fw_event;
         Mpi2EventNotificationReply_t *mpi_reply;
-        unsigned long flags;
         u16 event;
 
         /* events turned off due to host reset or driver unloading */
-        spin_lock_irqsave(&ioc->fw_event_lock, flags);
-        if (ioc->fw_events_off || ioc->remove_host) {
-                spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
+        if (ioc->remove_host)
                 return 1;
-        }
-        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
 
         mpi_reply = mpt2sas_base_get_reply_virt_addr(ioc, reply);
         event = le16_to_cpu(mpi_reply->Event);
@@ -6158,6 +6156,18 @@ _scsih_shutdown(struct pci_dev *pdev)
 {
         struct Scsi_Host *shost = pci_get_drvdata(pdev);
         struct MPT2SAS_ADAPTER *ioc = shost_priv(shost);
+        struct workqueue_struct *wq;
+        unsigned long flags;
+
+        ioc->remove_host = 1;
+        _scsih_fw_event_cleanup_queue(ioc);
+
+        spin_lock_irqsave(&ioc->fw_event_lock, flags);
+        wq = ioc->firmware_event_thread;
+        ioc->firmware_event_thread = NULL;
+        spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
+        if (wq)
+                destroy_workqueue(wq);
 
         _scsih_ir_shutdown(ioc);
         mpt2sas_base_detach(ioc);
@@ -6184,7 +6194,7 @@ _scsih_remove(struct pci_dev *pdev)
         unsigned long flags;
 
         ioc->remove_host = 1;
-        _scsih_fw_event_off(ioc);
+        _scsih_fw_event_cleanup_queue(ioc);
 
         spin_lock_irqsave(&ioc->fw_event_lock, flags);
         wq = ioc->firmware_event_thread;