From b2c03941b50944a268ee4d5823872f220809a3ba Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Wed, 6 Dec 2006 20:41:00 -0800 Subject: [PATCH] IPMI: Allow hot system interface remove This modifies the IPMI driver so that a lower-level interface can be dynamically removed while in use so it can support hot-removal of hardware. It also adds the ability to specify and dynamically change the IPMI interface the watchdog timer and the poweroff code use. Signed-off-by: Corey Minyard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/ipmi/ipmi_watchdog.c | 121 ++++++++++++++++++++++++-------------- 1 file changed, 78 insertions(+), 43 deletions(-) (limited to 'drivers/char/ipmi/ipmi_watchdog.c') diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c index 73f759eaa5a6..90fb2a541916 100644 --- a/drivers/char/ipmi/ipmi_watchdog.c +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -135,6 +135,7 @@ static int nowayout = WATCHDOG_NOWAYOUT; static ipmi_user_t watchdog_user = NULL; +static int watchdog_ifnum; /* Default the timeout to 10 seconds. */ static int timeout = 10; @@ -161,6 +162,8 @@ static struct fasync_struct *fasync_q = NULL; static char pretimeout_since_last_heartbeat = 0; static char expect_close; +static int ifnum_to_use = -1; + static DECLARE_RWSEM(register_sem); /* Parameters to ipmi_set_timeout */ @@ -169,6 +172,8 @@ static DECLARE_RWSEM(register_sem); #define IPMI_SET_TIMEOUT_FORCE_HB 2 static int ipmi_set_timeout(int do_heartbeat); +static void ipmi_register_watchdog(int ipmi_intf); +static void ipmi_unregister_watchdog(int ipmi_intf); /* If true, the driver will start running as soon as it is configured and ready. */ @@ -245,6 +250,26 @@ static int get_param_str(char *buffer, struct kernel_param *kp) return strlen(buffer); } + +static int set_param_wdog_ifnum(const char *val, struct kernel_param *kp) +{ + int rv = param_set_int(val, kp); + if (rv) + return rv; + if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) + return 0; + + ipmi_unregister_watchdog(watchdog_ifnum); + ipmi_register_watchdog(ifnum_to_use); + return 0; +} + +module_param_call(ifnum_to_use, set_param_wdog_ifnum, get_param_int, + &ifnum_to_use, 0644); +MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " + "timer. Setting to -1 defaults to the first registered " + "interface"); + module_param_call(timeout, set_param_int, get_param_int, &timeout, 0644); MODULE_PARM_DESC(timeout, "Timeout value in seconds."); @@ -263,12 +288,13 @@ module_param_call(preop, set_param_str, get_param_str, preop_op, 0644); MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " "preop_none, preop_panic, preop_give_data."); -module_param(start_now, int, 0); +module_param(start_now, int, 0444); MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" "soon as the driver is loaded."); module_param(nowayout, int, 0644); -MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=CONFIG_WATCHDOG_NOWAYOUT)"); /* Default state of the timer. */ static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; @@ -872,6 +898,11 @@ static void ipmi_register_watchdog(int ipmi_intf) if (watchdog_user) goto out; + if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) + goto out; + + watchdog_ifnum = ipmi_intf; + rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); if (rv < 0) { printk(KERN_CRIT PFX "Unable to register with ipmi\n"); @@ -901,6 +932,39 @@ static void ipmi_register_watchdog(int ipmi_intf) } } +static void ipmi_unregister_watchdog(int ipmi_intf) +{ + int rv; + + down_write(®ister_sem); + + if (!watchdog_user) + goto out; + + if (watchdog_ifnum != ipmi_intf) + goto out; + + /* Make sure no one can call us any more. */ + misc_deregister(&ipmi_wdog_miscdev); + + /* Wait to make sure the message makes it out. The lower layer has + pointers to our buffers, we want to make sure they are done before + we release our memory. */ + while (atomic_read(&set_timeout_tofree)) + schedule_timeout_uninterruptible(1); + + /* Disconnect from IPMI. */ + rv = ipmi_destroy_user(watchdog_user); + if (rv) { + printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n", + rv); + } + watchdog_user = NULL; + + out: + up_write(®ister_sem); +} + #ifdef HAVE_NMI_HANDLER static int ipmi_nmi(void *dev_id, int cpu, int handled) @@ -1004,9 +1068,7 @@ static void ipmi_new_smi(int if_num, struct device *device) static void ipmi_smi_gone(int if_num) { - /* This can never be called, because once the watchdog is - registered, the interface can't go away until the watchdog - is unregistered. */ + ipmi_unregister_watchdog(if_num); } static struct ipmi_smi_watcher smi_watcher = @@ -1148,30 +1210,32 @@ static int __init ipmi_wdog_init(void) check_parms(); + register_reboot_notifier(&wdog_reboot_notifier); + atomic_notifier_chain_register(&panic_notifier_list, + &wdog_panic_notifier); + rv = ipmi_smi_watcher_register(&smi_watcher); if (rv) { #ifdef HAVE_NMI_HANDLER if (preaction_val == WDOG_PRETIMEOUT_NMI) release_nmi(&ipmi_nmi_handler); #endif + atomic_notifier_chain_unregister(&panic_notifier_list, + &wdog_panic_notifier); + unregister_reboot_notifier(&wdog_reboot_notifier); printk(KERN_WARNING PFX "can't register smi watcher\n"); return rv; } - register_reboot_notifier(&wdog_reboot_notifier); - atomic_notifier_chain_register(&panic_notifier_list, - &wdog_panic_notifier); - printk(KERN_INFO PFX "driver initialized\n"); return 0; } -static __exit void ipmi_unregister_watchdog(void) +static void __exit ipmi_wdog_exit(void) { - int rv; - - down_write(®ister_sem); + ipmi_smi_watcher_unregister(&smi_watcher); + ipmi_unregister_watchdog(watchdog_ifnum); #ifdef HAVE_NMI_HANDLER if (nmi_handler_registered) @@ -1179,37 +1243,8 @@ static __exit void ipmi_unregister_watchdog(void) #endif atomic_notifier_chain_unregister(&panic_notifier_list, - &wdog_panic_notifier); + &wdog_panic_notifier); unregister_reboot_notifier(&wdog_reboot_notifier); - - if (! watchdog_user) - goto out; - - /* Make sure no one can call us any more. */ - misc_deregister(&ipmi_wdog_miscdev); - - /* Wait to make sure the message makes it out. The lower layer has - pointers to our buffers, we want to make sure they are done before - we release our memory. */ - while (atomic_read(&set_timeout_tofree)) - schedule_timeout_uninterruptible(1); - - /* Disconnect from IPMI. */ - rv = ipmi_destroy_user(watchdog_user); - if (rv) { - printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n", - rv); - } - watchdog_user = NULL; - - out: - up_write(®ister_sem); -} - -static void __exit ipmi_wdog_exit(void) -{ - ipmi_smi_watcher_unregister(&smi_watcher); - ipmi_unregister_watchdog(); } module_exit(ipmi_wdog_exit); module_init(ipmi_wdog_init); -- cgit v1.2.3