[PATCH] IPMI: Add maintenance mode

Some commands and operations on a BMC can cause the BMC to "go away" for a
while.  This can cause the automatic flag processing and other things of that
nature to timeout and generate annoying logs, or possibly cause other bad
things to happen when in firmware update mode.

Add detection of those commands (cold reset, warm reset, and any firmware
command) and turns off automatic processing for 30 seconds.  It also add a
manual override either way.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 116 insertions, 1 deletions

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 03f32611831d..ff0e68f0386b 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -48,7 +48,7 @@
 
 #define PFX "IPMI message handler: "
 
-#define IPMI_DRIVER_VERSION "39.0"
+#define IPMI_DRIVER_VERSION "39.1"
 
 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
 static int ipmi_init_msghandler(void);
@@ -59,6 +59,9 @@ static int initialized = 0;
 static struct proc_dir_entry *proc_ipmi_root = NULL;
 #endif /* CONFIG_PROC_FS */
 
+/* Remain in auto-maintenance mode for this amount of time (in ms). */
+#define IPMI_MAINTENANCE_MODE_TIMEOUT 30000
+
 #define MAX_EVENTS_IN_QUEUE     25
 
 /* Don't let a message sit in a queue forever, always time it with at lest
@@ -262,6 +265,12 @@ struct ipmi_smi
         unsigned char local_sel_device;
         unsigned char local_event_generator;
 
+        /* For handling of maintenance mode. */
+        int maintenance_mode;
+        int maintenance_mode_enable;
+        int auto_maintenance_timeout;
+        spinlock_t maintenance_mode_lock; /* Used in a timer... */
+
         /* A cheap hack, if this is non-null and a message to an
            interface comes in with a NULL user, call this routine with
            it.  Note that the message will still be freed by the
@@ -985,6 +994,65 @@ int ipmi_get_my_LUN(ipmi_user_t   user,
         return 0;
 }
 
+int ipmi_get_maintenance_mode(ipmi_user_t user)
+{
+        int           mode;
+        unsigned long flags;
+
+        spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
+        mode = user->intf->maintenance_mode;
+        spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
+
+        return mode;
+}
+EXPORT_SYMBOL(ipmi_get_maintenance_mode);
+
+static void maintenance_mode_update(ipmi_smi_t intf)
+{
+        if (intf->handlers->set_maintenance_mode)
+                intf->handlers->set_maintenance_mode(
+                        intf->send_info, intf->maintenance_mode_enable);
+}
+
+int ipmi_set_maintenance_mode(ipmi_user_t user, int mode)
+{
+        int           rv = 0;
+        unsigned long flags;
+        ipmi_smi_t    intf = user->intf;
+
+        spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
+        if (intf->maintenance_mode != mode) {
+                switch (mode) {
+                case IPMI_MAINTENANCE_MODE_AUTO:
+                        intf->maintenance_mode = mode;
+                        intf->maintenance_mode_enable
+                                = (intf->auto_maintenance_timeout > 0);
+                        break;
+
+                case IPMI_MAINTENANCE_MODE_OFF:
+                        intf->maintenance_mode = mode;
+                        intf->maintenance_mode_enable = 0;
+                        break;
+
+                case IPMI_MAINTENANCE_MODE_ON:
+                        intf->maintenance_mode = mode;
+                        intf->maintenance_mode_enable = 1;
+                        break;
+
+                default:
+                        rv = -EINVAL;
+                        goto out_unlock;
+                }
+
+                maintenance_mode_update(intf);
+        }
+ out_unlock:
+        spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
+
+        return rv;
+}
+EXPORT_SYMBOL(ipmi_set_maintenance_mode);
+
 int ipmi_set_gets_events(ipmi_user_t user, int val)
 {
         unsigned long        flags;
@@ -1322,6 +1390,24 @@ static int i_ipmi_request(ipmi_user_t          user,
                         goto out_err;
                 }
 
+                if (((msg->netfn == IPMI_NETFN_APP_REQUEST)
+                      && ((msg->cmd == IPMI_COLD_RESET_CMD)
+                          || (msg->cmd == IPMI_WARM_RESET_CMD)))
+                     || (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST))
+                {
+                        spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
+                        intf->auto_maintenance_timeout
+                                = IPMI_MAINTENANCE_MODE_TIMEOUT;
+                        if (!intf->maintenance_mode
+                            && !intf->maintenance_mode_enable)
+                        {
+                                intf->maintenance_mode_enable = 1;
+                                maintenance_mode_update(intf);
+                        }
+                        spin_unlock_irqrestore(&intf->maintenance_mode_lock,
+                                               flags);
+                }
+
                 if ((msg->data_len + 2) > IPMI_MAX_MSG_LENGTH) {
                         spin_lock_irqsave(&intf->counter_lock, flags);
                         intf->sent_invalid_commands++;
@@ -2605,6 +2691,7 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
         INIT_LIST_HEAD(&intf->waiting_events);
         intf->waiting_events_count = 0;
         mutex_init(&intf->cmd_rcvrs_mutex);
+        spin_lock_init(&intf->maintenance_mode_lock);
         INIT_LIST_HEAD(&intf->cmd_rcvrs);
         init_waitqueue_head(&intf->waitq);
 
@@ -3593,6 +3680,30 @@ static void ipmi_timeout_handler(long timeout_period)
 
                 list_for_each_entry_safe(msg, msg2, &timeouts, link)
                         deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
+
+                /*
+                 * Maintenance mode handling.  Check the timeout
+                 * optimistically before we claim the lock.  It may
+                 * mean a timeout gets missed occasionally, but that
+                 * only means the timeout gets extended by one period
+                 * in that case.  No big deal, and it avoids the lock
+                 * most of the time.
+                 */
+                if (intf->auto_maintenance_timeout > 0) {
+                        spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
+                        if (intf->auto_maintenance_timeout > 0) {
+                                intf->auto_maintenance_timeout
+                                        -= timeout_period;
+                                if (!intf->maintenance_mode
+                                    && (intf->auto_maintenance_timeout <= 0))
+                                {
+                                        intf->maintenance_mode_enable = 0;
+                                        maintenance_mode_update(intf);
+                                }
+                        }
+                        spin_unlock_irqrestore(&intf->maintenance_mode_lock,
+                                               flags);
+                }
         }
         rcu_read_unlock();
 }
@@ -3606,6 +3717,10 @@ static void ipmi_request_event(void)
         /* Called from the timer, no need to check if handlers is
          * valid. */
         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
+                /* No event requests when in maintenance mode. */
+                if (intf->maintenance_mode_enable)
+                        continue;
+
                 handlers = intf->handlers;
                 if (handlers)
                         handlers->request_events(intf->send_info);