ipmi: simplify locking

Now that the the IPMI driver is using a tasklet, we can simplify the
locking in the driver and get rid of the message lock.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 21 insertions, 33 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 01e53cd105dd..3c7e693018d9 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -171,7 +171,6 @@ struct smi_info {
         struct si_sm_handlers  *handlers;
         enum si_type           si_type;
         spinlock_t             si_lock;
-        spinlock_t             msg_lock;
         struct list_head       xmit_msgs;
         struct list_head       hp_xmit_msgs;
         struct ipmi_smi_msg    *curr_msg;
@@ -350,13 +349,6 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
         struct timeval t;
 #endif
 
-        /*
-         * No need to save flags, we aleady have interrupts off and we
-         * already hold the SMI lock.
-         */
-        if (!smi_info->run_to_completion)
-                spin_lock(&(smi_info->msg_lock));
-
         /* Pick the high priority queue first. */
         if (!list_empty(&(smi_info->hp_xmit_msgs))) {
                 entry = smi_info->hp_xmit_msgs.next;
@@ -394,9 +386,6 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
                 rv = SI_SM_CALL_WITHOUT_DELAY;
         }
  out:
-        if (!smi_info->run_to_completion)
-                spin_unlock(&(smi_info->msg_lock));
-
         return rv;
 }
 
@@ -879,19 +868,6 @@ static void sender(void                *send_info,
         printk("**Enqueue: %d.%9.9d\n", t.tv_sec, t.tv_usec);
 #endif
 
-        /*
-         * last_timeout_jiffies is updated here to avoid
-         * smi_timeout() handler passing very large time_diff
-         * value to smi_event_handler() that causes
-         * the send command to abort.
-         */
-        smi_info->last_timeout_jiffies = jiffies;
-
-        mod_timer(&smi_info->si_timer, jiffies + SI_TIMEOUT_JIFFIES);
-
-        if (smi_info->thread)
-                wake_up_process(smi_info->thread);
-
         if (smi_info->run_to_completion) {
                 /*
                  * If we are running to completion, then throw it in
@@ -914,15 +890,26 @@ static void sender(void                *send_info,
                 return;
         }
 
-        spin_lock_irqsave(&smi_info->msg_lock, flags);
+        spin_lock_irqsave(&smi_info->si_lock, flags);
         if (priority > 0)
                 list_add_tail(&msg->link, &smi_info->hp_xmit_msgs);
         else
                 list_add_tail(&msg->link, &smi_info->xmit_msgs);
-        spin_unlock_irqrestore(&smi_info->msg_lock, flags);
 
-        spin_lock_irqsave(&smi_info->si_lock, flags);
         if (smi_info->si_state == SI_NORMAL && smi_info->curr_msg == NULL) {
+                /*
+                 * last_timeout_jiffies is updated here to avoid
+                 * smi_timeout() handler passing very large time_diff
+                 * value to smi_event_handler() that causes
+                 * the send command to abort.
+                 */
+                smi_info->last_timeout_jiffies = jiffies;
+
+                mod_timer(&smi_info->si_timer, jiffies + SI_TIMEOUT_JIFFIES);
+
+                if (smi_info->thread)
+                        wake_up_process(smi_info->thread);
+
                 start_next_msg(smi_info);
                 smi_event_handler(smi_info, 0);
         }
@@ -1026,16 +1013,19 @@ static int ipmi_thread(void *data)
 static void poll(void *send_info)
 {
         struct smi_info *smi_info = send_info;
-        unsigned long flags;
+        unsigned long flags = 0;
+        int run_to_completion = smi_info->run_to_completion;
 
         /*
          * Make sure there is some delay in the poll loop so we can
          * drive time forward and timeout things.
          */
         udelay(10);
-        spin_lock_irqsave(&smi_info->si_lock, flags);
+        if (!run_to_completion)
+                spin_lock_irqsave(&smi_info->si_lock, flags);
         smi_event_handler(smi_info, 10);
-        spin_unlock_irqrestore(&smi_info->si_lock, flags);
+        if (!run_to_completion)
+                spin_unlock_irqrestore(&smi_info->si_lock, flags);
 }
 
 static void request_events(void *send_info)
@@ -1672,10 +1662,8 @@ static struct smi_info *smi_info_alloc(void)
 {
         struct smi_info *info = kzalloc(sizeof(*info), GFP_KERNEL);
 
-        if (info) {
+        if (info)
                 spin_lock_init(&info->si_lock);
-                spin_lock_init(&info->msg_lock);
-        }
         return info;
 }