Merge branch 'akpm' (Andrew's patch-bomb)

Merge third batch of patches from Andrew Morton:
 - Some MM stragglers
 - core SMP library cleanups (on_each_cpu_mask)
 - Some IPI optimisations
 - kexec
 - kdump
 - IPMI
 - the radix-tree iterator work
 - various other misc bits.

 "That'll do for -rc1.  I still have ~10 patches for 3.4, will send
  those along when they've baked a little more."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  backlight: fix typo in tosa_lcd.c
  crc32: add help text for the algorithm select option
  mm: move hugepage test examples to tools/testing/selftests/vm
  mm: move slabinfo.c to tools/vm
  mm: move page-types.c from Documentation to tools/vm
  selftests/Makefile: make `run_tests' depend on `all'
  selftests: launch individual selftests from the main Makefile
  radix-tree: use iterators in find_get_pages* functions
  radix-tree: rewrite gang lookup using iterator
  radix-tree: introduce bit-optimized iterator
  fs/proc/namespaces.c: prevent crash when ns_entries[] is empty
  nbd: rename the nbd_device variable from lo to nbd
  pidns: add reboot_pid_ns() to handle the reboot syscall
  sysctl: use bitmap library functions
  ipmi: use locks on watchdog timeout set on reboot
  ipmi: simplify locking
  ipmi: fix message handling during panics
  ipmi: use a tasklet for handling received messages
  ipmi: increase KCS timeouts
  ipmi: decrease the IPMI message transaction time in interrupt mode
  ...

1 files changed, 131 insertions, 111 deletions

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index c90e9390b78c..2c29942b1326 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -45,6 +45,7 @@
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/rcupdate.h>
+#include <linux/interrupt.h>
 
 #define PFX "IPMI message handler: "
 
@@ -52,6 +53,8 @@
 
 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
 static int ipmi_init_msghandler(void);
+static void smi_recv_tasklet(unsigned long);
+static void handle_new_recv_msgs(ipmi_smi_t intf);
 
 static int initialized;
 
@@ -354,12 +357,15 @@ struct ipmi_smi {
 	int curr_seq;
 
 	/*
-	 * Messages that were delayed for some reason (out of memory,
-	 * for instance), will go in here to be processed later in a
-	 * periodic timer interrupt.
+	 * Messages queued for delivery.  If delivery fails (out of memory
+	 * for instance), They will stay in here to be processed later in a
+	 * periodic timer interrupt.  The tasklet is for handling received
+	 * messages directly from the handler.
 	 */
 	spinlock_t       waiting_msgs_lock;
 	struct list_head waiting_msgs;
+	atomic_t	 watchdog_pretimeouts_to_deliver;
+	struct tasklet_struct recv_tasklet;
 
 	/*
 	 * The list of command receivers that are registered for commands
@@ -492,6 +498,8 @@ static void clean_up_interface_data(ipmi_smi_t intf)
 	struct cmd_rcvr  *rcvr, *rcvr2;
 	struct list_head list;
 
+	tasklet_kill(&intf->recv_tasklet);
+
 	free_smi_msg_list(&intf->waiting_msgs);
 	free_recv_msg_list(&intf->waiting_events);
 
@@ -2785,12 +2793,17 @@ channel_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
 	return;
 }
 
-void ipmi_poll_interface(ipmi_user_t user)
+static void ipmi_poll(ipmi_smi_t intf)
 {
-	ipmi_smi_t intf = user->intf;
-
 	if (intf->handlers->poll)
 		intf->handlers->poll(intf->send_info);
+	/* In case something came in */
+	handle_new_recv_msgs(intf);
+}
+
+void ipmi_poll_interface(ipmi_user_t user)
+{
+	ipmi_poll(user->intf);
 }
 EXPORT_SYMBOL(ipmi_poll_interface);
 
@@ -2859,6 +2872,10 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
 #endif
 	spin_lock_init(&intf->waiting_msgs_lock);
 	INIT_LIST_HEAD(&intf->waiting_msgs);
+	tasklet_init(&intf->recv_tasklet,
+		     smi_recv_tasklet,
+		     (unsigned long) intf);
+	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
 	spin_lock_init(&intf->events_lock);
 	INIT_LIST_HEAD(&intf->waiting_events);
 	intf->waiting_events_count = 0;
@@ -3621,11 +3638,11 @@ static int handle_bmc_rsp(ipmi_smi_t          intf,
 }
 
 /*
- * Handle a new message.  Return 1 if the message should be requeued,
+ * Handle a received message.  Return 1 if the message should be requeued,
  * 0 if the message should be freed, or -1 if the message should not
  * be freed or requeued.
  */
-static int handle_new_recv_msg(ipmi_smi_t          intf,
+static int handle_one_recv_msg(ipmi_smi_t          intf,
 			       struct ipmi_smi_msg *msg)
 {
 	int requeue;
@@ -3783,12 +3800,72 @@ static int handle_new_recv_msg(ipmi_smi_t          intf,
 	return requeue;
 }
 
+/*
+ * If there are messages in the queue or pretimeouts, handle them.
+ */
+static void handle_new_recv_msgs(ipmi_smi_t intf)
+{
+	struct ipmi_smi_msg  *smi_msg;
+	unsigned long        flags = 0;
+	int                  rv;
+	int                  run_to_completion = intf->run_to_completion;
+
+	/* See if any waiting messages need to be processed. */
+	if (!run_to_completion)
+		spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
+	while (!list_empty(&intf->waiting_msgs)) {
+		smi_msg = list_entry(intf->waiting_msgs.next,
+				     struct ipmi_smi_msg, link);
+		list_del(&smi_msg->link);
+		if (!run_to_completion)
+			spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
+		rv = handle_one_recv_msg(intf, smi_msg);
+		if (!run_to_completion)
+			spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
+		if (rv == 0) {
+			/* Message handled */
+			ipmi_free_smi_msg(smi_msg);
+		} else if (rv < 0) {
+			/* Fatal error on the message, del but don't free. */
+		} else {
+			/*
+			 * To preserve message order, quit if we
+			 * can't handle a message.
+			 */
+			list_add(&smi_msg->link, &intf->waiting_msgs);
+			break;
+		}
+	}
+	if (!run_to_completion)
+		spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
+
+	/*
+	 * If the pretimout count is non-zero, decrement one from it and
+	 * deliver pretimeouts to all the users.
+	 */
+	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
+		ipmi_user_t user;
+
+		rcu_read_lock();
+		list_for_each_entry_rcu(user, &intf->users, link) {
+			if (user->handler->ipmi_watchdog_pretimeout)
+				user->handler->ipmi_watchdog_pretimeout(
+					user->handler_data);
+		}
+		rcu_read_unlock();
+	}
+}
+
+static void smi_recv_tasklet(unsigned long val)
+{
+	handle_new_recv_msgs((ipmi_smi_t) val);
+}
+
 /* Handle a new message from the lower layer. */
 void ipmi_smi_msg_received(ipmi_smi_t          intf,
 			   struct ipmi_smi_msg *msg)
 {
 	unsigned long flags = 0; /* keep us warning-free. */
-	int           rv;
 	int           run_to_completion;
 
 
@@ -3842,31 +3919,11 @@ void ipmi_smi_msg_received(ipmi_smi_t          intf,
 	run_to_completion = intf->run_to_completion;
 	if (!run_to_completion)
 		spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
-	if (!list_empty(&intf->waiting_msgs)) {
-		list_add_tail(&msg->link, &intf->waiting_msgs);
-		if (!run_to_completion)
-			spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
-		goto out;
-	}
+	list_add_tail(&msg->link, &intf->waiting_msgs);
 	if (!run_to_completion)
 		spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
 
-	rv = handle_new_recv_msg(intf, msg);
-	if (rv > 0) {
-		/*
-		 * Could not handle the message now, just add it to a
-		 * list to handle later.
-		 */
-		run_to_completion = intf->run_to_completion;
-		if (!run_to_completion)
-			spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
-		list_add_tail(&msg->link, &intf->waiting_msgs);
-		if (!run_to_completion)
-			spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
-	} else if (rv == 0) {
-		ipmi_free_smi_msg(msg);
-	}
-
+	tasklet_schedule(&intf->recv_tasklet);
  out:
 	return;
 }
@@ -3874,16 +3931,8 @@ EXPORT_SYMBOL(ipmi_smi_msg_received);
 
 void ipmi_smi_watchdog_pretimeout(ipmi_smi_t intf)
 {
-	ipmi_user_t user;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(user, &intf->users, link) {
-		if (!user->handler->ipmi_watchdog_pretimeout)
-			continue;
-
-		user->handler->ipmi_watchdog_pretimeout(user->handler_data);
-	}
-	rcu_read_unlock();
+	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
+	tasklet_schedule(&intf->recv_tasklet);
 }
 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
 
@@ -3997,28 +4046,12 @@ static void ipmi_timeout_handler(long timeout_period)
 	ipmi_smi_t           intf;
 	struct list_head     timeouts;
 	struct ipmi_recv_msg *msg, *msg2;
-	struct ipmi_smi_msg  *smi_msg, *smi_msg2;
 	unsigned long        flags;
 	int                  i;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
-		/* See if any waiting messages need to be processed. */
-		spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
-		list_for_each_entry_safe(smi_msg, smi_msg2,
-					 &intf->waiting_msgs, link) {
-			if (!handle_new_recv_msg(intf, smi_msg)) {
-				list_del(&smi_msg->link);
-				ipmi_free_smi_msg(smi_msg);
-			} else {
-				/*
-				 * To preserve message order, quit if we
-				 * can't handle a message.
-				 */
-				break;
-			}
-		}
-		spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
+		tasklet_schedule(&intf->recv_tasklet);
 
 		/*
 		 * Go through the seq table and find any messages that
@@ -4172,12 +4205,48 @@ EXPORT_SYMBOL(ipmi_free_recv_msg);
 
 #ifdef CONFIG_IPMI_PANIC_EVENT
 
+static atomic_t panic_done_count = ATOMIC_INIT(0);
+
 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
 {
+	atomic_dec(&panic_done_count);
 }
 
 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
 {
+	atomic_dec(&panic_done_count);
+}
+
+/*
+ * Inside a panic, send a message and wait for a response.
+ */
+static void ipmi_panic_request_and_wait(ipmi_smi_t           intf,
+					struct ipmi_addr     *addr,
+					struct kernel_ipmi_msg *msg)
+{
+	struct ipmi_smi_msg  smi_msg;
+	struct ipmi_recv_msg recv_msg;
+	int rv;
+
+	smi_msg.done = dummy_smi_done_handler;
+	recv_msg.done = dummy_recv_done_handler;
+	atomic_add(2, &panic_done_count);
+	rv = i_ipmi_request(NULL,
+			    intf,
+			    addr,
+			    0,
+			    msg,
+			    intf,
+			    &smi_msg,
+			    &recv_msg,
+			    0,
+			    intf->channels[0].address,
+			    intf->channels[0].lun,
+			    0, 1); /* Don't retry, and don't wait. */
+	if (rv)
+		atomic_sub(2, &panic_done_count);
+	while (atomic_read(&panic_done_count) != 0)
+		ipmi_poll(intf);
 }
 
 #ifdef CONFIG_IPMI_PANIC_STRING
@@ -4216,8 +4285,6 @@ static void send_panic_events(char *str)
 	unsigned char                     data[16];
 	struct ipmi_system_interface_addr *si;
 	struct ipmi_addr                  addr;
-	struct ipmi_smi_msg               smi_msg;
-	struct ipmi_recv_msg              recv_msg;
 
 	si = (struct ipmi_system_interface_addr *) &addr;
 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
@@ -4245,9 +4312,6 @@ static void send_panic_events(char *str)
 		data[7] = str[2];
 	}
 
-	smi_msg.done = dummy_smi_done_handler;
-	recv_msg.done = dummy_recv_done_handler;
-
 	/* For every registered interface, send the event. */
 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
 		if (!intf->handlers)
@@ -4257,18 +4321,7 @@ static void send_panic_events(char *str)
 		intf->run_to_completion = 1;
 		/* Send the event announcing the panic. */
 		intf->handlers->set_run_to_completion(intf->send_info, 1);
-		i_ipmi_request(NULL,
-			       intf,
-			       &addr,
-			       0,
-			       &msg,
-			       intf,
-			       &smi_msg,
-			       &recv_msg,
-			       0,
-			       intf->channels[0].address,
-			       intf->channels[0].lun,
-			       0, 1); /* Don't retry, and don't wait. */
+		ipmi_panic_request_and_wait(intf, &addr, &msg);
 	}
 
 #ifdef CONFIG_IPMI_PANIC_STRING
@@ -4316,18 +4369,7 @@ static void send_panic_events(char *str)
 		msg.data = NULL;
 		msg.data_len = 0;
 		intf->null_user_handler = device_id_fetcher;
-		i_ipmi_request(NULL,
-			       intf,
-			       &addr,
-			       0,
-			       &msg,
-			       intf,
-			       &smi_msg,
-			       &recv_msg,
-			       0,
-			       intf->channels[0].address,
-			       intf->channels[0].lun,
-			       0, 1); /* Don't retry, and don't wait. */
+		ipmi_panic_request_and_wait(intf, &addr, &msg);
 
 		if (intf->local_event_generator) {
 			/* Request the event receiver from the local MC. */
@@ -4336,18 +4378,7 @@ static void send_panic_events(char *str)
 			msg.data = NULL;
 			msg.data_len = 0;
 			intf->null_user_handler = event_receiver_fetcher;
-			i_ipmi_request(NULL,
-				       intf,
-				       &addr,
-				       0,
-				       &msg,
-				       intf,
-				       &smi_msg,
-				       &recv_msg,
-				       0,
-				       intf->channels[0].address,
-				       intf->channels[0].lun,
-				       0, 1); /* no retry, and no wait. */
+			ipmi_panic_request_and_wait(intf, &addr, &msg);
 		}
 		intf->null_user_handler = NULL;
 
@@ -4404,18 +4435,7 @@ static void send_panic_events(char *str)
 			strncpy(data+5, p, 11);
 			p += size;
 
-			i_ipmi_request(NULL,
-				       intf,
-				       &addr,
-				       0,
-				       &msg,
-				       intf,
-				       &smi_msg,
-				       &recv_msg,
-				       0,
-				       intf->channels[0].address,
-				       intf->channels[0].lun,
-				       0, 1); /* no retry, and no wait. */
+			ipmi_panic_request_and_wait(intf, &addr, &msg);
 		}
 	}
 #endif /* CONFIG_IPMI_PANIC_STRING */