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>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 01e53cd105dd000f6e75df674df85f3c015aad53..3c7e693018d90c53687e38e0ebc8340a5685674b 100644 (file)
--- 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;
 }