From bda4c30aa6f7dc1483f39ea1dfe37bcab8a96207 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Tue, 29 Apr 2008 01:01:02 -0700 Subject: [PATCH] ipmi: run to completion fixes The "run_to_completion" mode was somewhat broken. Locks need to be avoided in run_to_completion mode, and it shouldn't be used by normal users, just internally for panic situations. This patch removes locks in run_to_completion mode and removes the user call for setting the mode. The only user was the poweroff code, but it was easily converted to use the polling interface. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Corey Minyard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/ipmi/ipmi_msghandler.c | 8 ------ drivers/char/ipmi/ipmi_poweroff.c | 20 +++++++++++--- drivers/char/ipmi/ipmi_si_intf.c | 43 +++++++++++++---------------- include/linux/ipmi.h | 11 ++------ 4 files changed, 37 insertions(+), 45 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 32b2b22996dc..9f0075ca34ba 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1197,13 +1197,6 @@ int ipmi_unregister_for_cmd(ipmi_user_t user, return rv; } -void ipmi_user_set_run_to_completion(ipmi_user_t user, int val) -{ - ipmi_smi_t intf = user->intf; - if (intf->handlers) - intf->handlers->set_run_to_completion(intf->send_info, val); -} - static unsigned char ipmb_checksum(unsigned char *data, int size) { @@ -4190,5 +4183,4 @@ EXPORT_SYMBOL(ipmi_get_my_address); EXPORT_SYMBOL(ipmi_set_my_LUN); EXPORT_SYMBOL(ipmi_get_my_LUN); EXPORT_SYMBOL(ipmi_smi_add_proc_entry); -EXPORT_SYMBOL(ipmi_user_set_run_to_completion); EXPORT_SYMBOL(ipmi_free_recv_msg); diff --git a/drivers/char/ipmi/ipmi_poweroff.c b/drivers/char/ipmi/ipmi_poweroff.c index b86186de7f07..b065a53d1ca8 100644 --- a/drivers/char/ipmi/ipmi_poweroff.c +++ b/drivers/char/ipmi/ipmi_poweroff.c @@ -99,11 +99,14 @@ static unsigned char ipmi_version; allocate them, since we may be in a panic situation. The whole thing is single-threaded, anyway, so multiple messages are not required. */ +static atomic_t dummy_count = ATOMIC_INIT(0); static void dummy_smi_free(struct ipmi_smi_msg *msg) { + atomic_dec(&dummy_count); } static void dummy_recv_free(struct ipmi_recv_msg *msg) { + atomic_dec(&dummy_count); } static struct ipmi_smi_msg halt_smi_msg = { @@ -152,17 +155,28 @@ static int ipmi_request_wait_for_response(ipmi_user_t user, return halt_recv_msg.msg.data[0]; } -/* We are in run-to-completion mode, no completion is desired. */ +/* Wait for message to complete, spinning. */ static int ipmi_request_in_rc_mode(ipmi_user_t user, struct ipmi_addr *addr, struct kernel_ipmi_msg *send_msg) { int rv; + atomic_set(&dummy_count, 2); rv = ipmi_request_supply_msgs(user, addr, 0, send_msg, NULL, &halt_smi_msg, &halt_recv_msg, 0); - if (rv) + if (rv) { + atomic_set(&dummy_count, 0); return rv; + } + + /* + * Spin until our message is done. + */ + while (atomic_read(&dummy_count) > 0) { + ipmi_poll_interface(user); + cpu_relax(); + } return halt_recv_msg.msg.data[0]; } @@ -531,9 +545,7 @@ static void ipmi_poweroff_function (void) return; /* Use run-to-completion mode, since interrupts may be off. */ - ipmi_user_set_run_to_completion(ipmi_user, 1); specific_poweroff_func(ipmi_user); - ipmi_user_set_run_to_completion(ipmi_user, 0); } /* Wait for an IPMI interface to be installed, the first one installed diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 1a8c1ca90557..30f535657342 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -806,56 +806,53 @@ static void sender(void *send_info, return; } - spin_lock_irqsave(&(smi_info->msg_lock), flags); #ifdef DEBUG_TIMING do_gettimeofday(&t); printk("**Enqueue: %d.%9.9d\n", t.tv_sec, t.tv_usec); #endif 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, then throw it in + * the list and run transactions until everything is + * clear. Priority doesn't matter here. + */ + + /* + * Run to completion means we are single-threaded, no + * need for locks. + */ list_add_tail(&(msg->link), &(smi_info->xmit_msgs)); - /* We have to release the msg lock and claim the smi - lock in this case, because of race conditions. */ - spin_unlock_irqrestore(&(smi_info->msg_lock), flags); - - spin_lock_irqsave(&(smi_info->si_lock), flags); result = smi_event_handler(smi_info, 0); while (result != SI_SM_IDLE) { udelay(SI_SHORT_TIMEOUT_USEC); result = smi_event_handler(smi_info, SI_SHORT_TIMEOUT_USEC); } - spin_unlock_irqrestore(&(smi_info->si_lock), flags); return; - } else { - 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); + spin_lock_irqsave(&smi_info->msg_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)) { start_next_msg(smi_info); } - spin_unlock_irqrestore(&(smi_info->si_lock), flags); + spin_unlock_irqrestore(&smi_info->si_lock, flags); } static void set_run_to_completion(void *send_info, int i_run_to_completion) { struct smi_info *smi_info = send_info; enum si_sm_result result; - unsigned long flags; - - spin_lock_irqsave(&(smi_info->si_lock), flags); smi_info->run_to_completion = i_run_to_completion; if (i_run_to_completion) { @@ -866,8 +863,6 @@ static void set_run_to_completion(void *send_info, int i_run_to_completion) SI_SHORT_TIMEOUT_USEC); } } - - spin_unlock_irqrestore(&(smi_info->si_lock), flags); } static int ipmi_thread(void *data) diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h index c5bd28b69aec..1144b32f5310 100644 --- a/include/linux/ipmi.h +++ b/include/linux/ipmi.h @@ -368,9 +368,8 @@ int ipmi_request_supply_msgs(ipmi_user_t user, * Poll the IPMI interface for the user. This causes the IPMI code to * do an immediate check for information from the driver and handle * anything that is immediately pending. This will not block in any - * way. This is useful if you need to implement polling from the user - * for things like modifying the watchdog timeout when a panic occurs - * or disabling the watchdog timer on a reboot. + * way. This is useful if you need to spin waiting for something to + * happen in the IPMI driver. */ void ipmi_poll_interface(ipmi_user_t user); @@ -421,12 +420,6 @@ int ipmi_unregister_for_cmd(ipmi_user_t user, int ipmi_get_maintenance_mode(ipmi_user_t user); int ipmi_set_maintenance_mode(ipmi_user_t user, int mode); -/* - * Allow run-to-completion mode to be set for the interface of - * a specific user. - */ -void ipmi_user_set_run_to_completion(ipmi_user_t user, int val); - /* * When the user is created, it will not receive IPMI events by * default. The user must set this to TRUE to get incoming events. -- 2.39.5