ipmi: Remove the now unnecessary message queue

A message queue was added to the message handler, so the SMI
interfaces only need to handle one message at a time.  Pull out
the message queue.  This also leads to some significant
simplification in the shutdown of an interface, since the
message handler now does a lot of the cleanup.

Signed-off-by: Corey Minyard <cminyard@mvista.com>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index e36487d..d31a7fc 100644 (file)
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -170,8 +170,7 @@ struct smi_info {
        struct si_sm_handlers  *handlers;
        enum si_type           si_type;
        spinlock_t             si_lock;
-       struct list_head       xmit_msgs;
-       struct list_head       hp_xmit_msgs;
+       struct ipmi_smi_msg    *waiting_msg;
        struct ipmi_smi_msg    *curr_msg;
        enum si_intf_state     si_state;
 
@@ -250,9 +249,6 @@ struct smi_info {
        /* The time (in jiffies) the last timeout occurred at. */
        unsigned long       last_timeout_jiffies;
 
-       /* Used to gracefully stop the timer without race conditions. */
-       atomic_t            stop_operation;
-
        /* Are we waiting for the events, pretimeouts, received msgs? */
        atomic_t            need_watch;
 
@@ -355,28 +351,18 @@ static void return_hosed_msg(struct smi_info *smi_info, int cCode)
 static enum si_sm_result start_next_msg(struct smi_info *smi_info)
 {
        int              rv;
-       struct list_head *entry = NULL;
 #ifdef DEBUG_TIMING
        struct timeval t;
 #endif
 
-       /* Pick the high priority queue first. */
-       if (!list_empty(&(smi_info->hp_xmit_msgs))) {
-               entry = smi_info->hp_xmit_msgs.next;
-       } else if (!list_empty(&(smi_info->xmit_msgs))) {
-               entry = smi_info->xmit_msgs.next;
-       }
-
-       if (!entry) {
+       if (!smi_info->waiting_msg) {
                smi_info->curr_msg = NULL;
                rv = SI_SM_IDLE;
        } else {
                int err;
 
-               list_del(entry);
-               smi_info->curr_msg = list_entry(entry,
-                                               struct ipmi_smi_msg,
-                                               link);
+               smi_info->curr_msg = smi_info->waiting_msg;
+               smi_info->waiting_msg = NULL;
 #ifdef DEBUG_TIMING
                do_gettimeofday(&t);
                printk(KERN_DEBUG "**Start2: %d.%9.9d\n", t.tv_sec, t.tv_usec);
@@ -916,14 +902,8 @@ static void sender(void                *send_info,
        struct timeval    t;
 #endif
 
-       if (atomic_read(&smi_info->stop_operation)) {
-               msg->rsp[0] = msg->data[0] | 4;
-               msg->rsp[1] = msg->data[1];
-               msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
-               msg->rsp_size = 3;
-               deliver_recv_msg(smi_info, msg);
-               return;
-       }
+       BUG_ON(smi_info->waiting_msg);
+       smi_info->waiting_msg = msg;
 
 #ifdef DEBUG_TIMING
        do_gettimeofday(&t);
@@ -932,16 +912,16 @@ static void sender(void                *send_info,
 
        if (smi_info->run_to_completion) {
                /*
-                * If we are running to completion, then throw it in
-                * the list and run transactions until everything is
-                * clear.  Priority doesn't matter here.
+                * If we are running to completion, start it and run
+                * transactions until everything is clear.
                 */
+               smi_info->curr_msg = smi_info->waiting_msg;
+               smi_info->waiting_msg = NULL;
 
                /*
                 * Run to completion means we are single-threaded, no
                 * need for locks.
                 */
-               list_add_tail(&(msg->link), &(smi_info->xmit_msgs));
 
                result = smi_event_handler(smi_info, 0);
                while (result != SI_SM_IDLE) {
@@ -953,11 +933,6 @@ static void sender(void                *send_info,
        }
 
        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);
-
        check_start_timer_thread(smi_info);
        spin_unlock_irqrestore(&smi_info->si_lock, flags);
 }
@@ -1095,8 +1070,7 @@ static void request_events(void *send_info)
 {
        struct smi_info *smi_info = send_info;
 
-       if (atomic_read(&smi_info->stop_operation) ||
-                               !smi_info->has_event_buffer)
+       if (!smi_info->has_event_buffer)
                return;
 
        atomic_set(&smi_info->req_events, 1);
@@ -3220,15 +3194,10 @@ static void setup_xaction_handlers(struct smi_info *smi_info)
 
 static inline void wait_for_timer_and_thread(struct smi_info *smi_info)
 {
-       if (smi_info->intf) {
-               /*
-                * The timer and thread are only running if the
-                * interface has been started up and registered.
-                */
-               if (smi_info->thread != NULL)
-                       kthread_stop(smi_info->thread);
+       if (smi_info->thread != NULL)
+               kthread_stop(smi_info->thread);
+       if (smi_info->timer_running)
                del_timer_sync(&smi_info->si_timer);
-       }
 }
 
 static struct ipmi_default_vals
@@ -3403,8 +3372,7 @@ static int try_smi_init(struct smi_info *new_smi)
        setup_oem_data_handler(new_smi);
        setup_xaction_handlers(new_smi);
 
-       INIT_LIST_HEAD(&(new_smi->xmit_msgs));
-       INIT_LIST_HEAD(&(new_smi->hp_xmit_msgs));
+       new_smi->waiting_msg = NULL;
        new_smi->curr_msg = NULL;
        atomic_set(&new_smi->req_events, 0);
        new_smi->run_to_completion = false;
@@ -3412,7 +3380,6 @@ static int try_smi_init(struct smi_info *new_smi)
                atomic_set(&new_smi->stats[i], 0);
 
        new_smi->interrupt_disabled = true;
-       atomic_set(&new_smi->stop_operation, 0);
        atomic_set(&new_smi->need_watch, 0);
        new_smi->intf_num = smi_num;
        smi_num++;
@@ -3497,15 +3464,15 @@ static int try_smi_init(struct smi_info *new_smi)
        return 0;
 
  out_err_stop_timer:
-       atomic_inc(&new_smi->stop_operation);
        wait_for_timer_and_thread(new_smi);
 
  out_err:
        new_smi->interrupt_disabled = true;
 
        if (new_smi->intf) {
-               ipmi_unregister_smi(new_smi->intf);
+               ipmi_smi_t intf = new_smi->intf;
                new_smi->intf = NULL;
+               ipmi_unregister_smi(intf);
        }
 
        if (new_smi->irq_cleanup) {
@@ -3684,60 +3651,49 @@ module_init(init_ipmi_si);
 static void cleanup_one_si(struct smi_info *to_clean)
 {
        int           rv = 0;
-       unsigned long flags;
 
        if (!to_clean)
                return;
 
+       if (to_clean->intf) {
+               ipmi_smi_t intf = to_clean->intf;
+
+               to_clean->intf = NULL;
+               rv = ipmi_unregister_smi(intf);
+               if (rv) {
+                       pr_err(PFX "Unable to unregister device: errno=%d\n",
+                              rv);
+               }
+       }
+
        if (to_clean->dev)
                dev_set_drvdata(to_clean->dev, NULL);
 
        list_del(&to_clean->link);
 
-       /* Tell the driver that we are shutting down. */
-       atomic_inc(&to_clean->stop_operation);
-
        /*
-        * Make sure the timer and thread are stopped and will not run
-        * again.
+        * Make sure that interrupts, the timer and the thread are
+        * stopped and will not run again.
         */
+       if (to_clean->irq_cleanup)
+               to_clean->irq_cleanup(to_clean);
        wait_for_timer_and_thread(to_clean);
 
        /*
         * Timeouts are stopped, now make sure the interrupts are off
-        * for the device.  A little tricky with locks to make sure
-        * there are no races.
+        * in the BMC.  Note that timers and CPU interrupts are off,
+        * so no need for locks.
         */
-       spin_lock_irqsave(&to_clean->si_lock, flags);
        while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
-               spin_unlock_irqrestore(&to_clean->si_lock, flags);
                poll(to_clean);
                schedule_timeout_uninterruptible(1);
-               spin_lock_irqsave(&to_clean->si_lock, flags);
        }
        disable_si_irq(to_clean);
-       spin_unlock_irqrestore(&to_clean->si_lock, flags);
-       while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
-               poll(to_clean);
-               schedule_timeout_uninterruptible(1);
-       }
-
-       /* Clean up interrupts and make sure that everything is done. */
-       if (to_clean->irq_cleanup)
-               to_clean->irq_cleanup(to_clean);
        while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
                poll(to_clean);
                schedule_timeout_uninterruptible(1);
        }
 
-       if (to_clean->intf)
-               rv = ipmi_unregister_smi(to_clean->intf);
-
-       if (rv) {
-               printk(KERN_ERR PFX "Unable to unregister device: errno=%d\n",
-                      rv);
-       }
-
        if (to_clean->handlers)
                to_clean->handlers->cleanup(to_clean->si_sm);