diff options
Diffstat (limited to 'drivers/char/ipmi/ipmi_watchdog.c')
| -rw-r--r-- | drivers/char/ipmi/ipmi_watchdog.c | 1341 |
1 files changed, 1341 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c new file mode 100644 index 000000000..f016d54b2 --- /dev/null +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -0,0 +1,1341 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ipmi_watchdog.c + * + * A watchdog timer based upon the IPMI interface. + * + * Author: MontaVista Software, Inc. + * Corey Minyard <minyard@mvista.com> + * source@mvista.com + * + * Copyright 2002 MontaVista Software Inc. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/ipmi.h> +#include <linux/ipmi_smi.h> +#include <linux/mutex.h> +#include <linux/watchdog.h> +#include <linux/miscdevice.h> +#include <linux/init.h> +#include <linux/completion.h> +#include <linux/kdebug.h> +#include <linux/rwsem.h> +#include <linux/errno.h> +#include <linux/uaccess.h> +#include <linux/notifier.h> +#include <linux/nmi.h> +#include <linux/reboot.h> +#include <linux/wait.h> +#include <linux/poll.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/atomic.h> +#include <linux/sched/signal.h> + +#ifdef CONFIG_X86 +/* + * This is ugly, but I've determined that x86 is the only architecture + * that can reasonably support the IPMI NMI watchdog timeout at this + * time. If another architecture adds this capability somehow, it + * will have to be a somewhat different mechanism and I have no idea + * how it will work. So in the unlikely event that another + * architecture supports this, we can figure out a good generic + * mechanism for it at that time. + */ +#include <asm/kdebug.h> +#include <asm/nmi.h> +#define HAVE_DIE_NMI +#endif + +#define PFX "IPMI Watchdog: " + +/* + * The IPMI command/response information for the watchdog timer. + */ + +/* values for byte 1 of the set command, byte 2 of the get response. */ +#define WDOG_DONT_LOG (1 << 7) +#define WDOG_DONT_STOP_ON_SET (1 << 6) +#define WDOG_SET_TIMER_USE(byte, use) \ + byte = ((byte) & 0xf8) | ((use) & 0x7) +#define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7) +#define WDOG_TIMER_USE_BIOS_FRB2 1 +#define WDOG_TIMER_USE_BIOS_POST 2 +#define WDOG_TIMER_USE_OS_LOAD 3 +#define WDOG_TIMER_USE_SMS_OS 4 +#define WDOG_TIMER_USE_OEM 5 + +/* values for byte 2 of the set command, byte 3 of the get response. */ +#define WDOG_SET_PRETIMEOUT_ACT(byte, use) \ + byte = ((byte) & 0x8f) | (((use) & 0x7) << 4) +#define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7) +#define WDOG_PRETIMEOUT_NONE 0 +#define WDOG_PRETIMEOUT_SMI 1 +#define WDOG_PRETIMEOUT_NMI 2 +#define WDOG_PRETIMEOUT_MSG_INT 3 + +/* Operations that can be performed on a pretimout. */ +#define WDOG_PREOP_NONE 0 +#define WDOG_PREOP_PANIC 1 +/* Cause data to be available to read. Doesn't work in NMI mode. */ +#define WDOG_PREOP_GIVE_DATA 2 + +/* Actions to perform on a full timeout. */ +#define WDOG_SET_TIMEOUT_ACT(byte, use) \ + byte = ((byte) & 0xf8) | ((use) & 0x7) +#define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7) +#define WDOG_TIMEOUT_NONE 0 +#define WDOG_TIMEOUT_RESET 1 +#define WDOG_TIMEOUT_POWER_DOWN 2 +#define WDOG_TIMEOUT_POWER_CYCLE 3 + +/* + * Byte 3 of the get command, byte 4 of the get response is the + * pre-timeout in seconds. + */ + +/* Bits for setting byte 4 of the set command, byte 5 of the get response. */ +#define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1) +#define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2) +#define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3) +#define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4) +#define WDOG_EXPIRE_CLEAR_OEM (1 << 5) + +/* + * Setting/getting the watchdog timer value. This is for bytes 5 and + * 6 (the timeout time) of the set command, and bytes 6 and 7 (the + * timeout time) and 8 and 9 (the current countdown value) of the + * response. The timeout value is given in seconds (in the command it + * is 100ms intervals). + */ +#define WDOG_SET_TIMEOUT(byte1, byte2, val) \ + (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8) +#define WDOG_GET_TIMEOUT(byte1, byte2) \ + (((byte1) | ((byte2) << 8)) / 10) + +#define IPMI_WDOG_RESET_TIMER 0x22 +#define IPMI_WDOG_SET_TIMER 0x24 +#define IPMI_WDOG_GET_TIMER 0x25 + +#define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80 + +static DEFINE_MUTEX(ipmi_watchdog_mutex); +static bool nowayout = WATCHDOG_NOWAYOUT; + +static struct ipmi_user *watchdog_user; +static int watchdog_ifnum; + +/* Default the timeout to 10 seconds. */ +static int timeout = 10; + +/* The pre-timeout is disabled by default. */ +static int pretimeout; + +/* Default timeout to set on panic */ +static int panic_wdt_timeout = 255; + +/* Default action is to reset the board on a timeout. */ +static unsigned char action_val = WDOG_TIMEOUT_RESET; + +static char action[16] = "reset"; + +static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; + +static char preaction[16] = "pre_none"; + +static unsigned char preop_val = WDOG_PREOP_NONE; + +static char preop[16] = "preop_none"; +static DEFINE_SPINLOCK(ipmi_read_lock); +static char data_to_read; +static DECLARE_WAIT_QUEUE_HEAD(read_q); +static struct fasync_struct *fasync_q; +static atomic_t pretimeout_since_last_heartbeat; +static char expect_close; + +static int ifnum_to_use = -1; + +/* Parameters to ipmi_set_timeout */ +#define IPMI_SET_TIMEOUT_NO_HB 0 +#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 +#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. + */ +static int start_now; + +static int set_param_timeout(const char *val, const struct kernel_param *kp) +{ + char *endp; + int l; + int rv = 0; + + if (!val) + return -EINVAL; + l = simple_strtoul(val, &endp, 0); + if (endp == val) + return -EINVAL; + + *((int *)kp->arg) = l; + if (watchdog_user) + rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); + + return rv; +} + +static const struct kernel_param_ops param_ops_timeout = { + .set = set_param_timeout, + .get = param_get_int, +}; +#define param_check_timeout param_check_int + +typedef int (*action_fn)(const char *intval, char *outval); + +static int action_op(const char *inval, char *outval); +static int preaction_op(const char *inval, char *outval); +static int preop_op(const char *inval, char *outval); +static void check_parms(void); + +static int set_param_str(const char *val, const struct kernel_param *kp) +{ + action_fn fn = (action_fn) kp->arg; + int rv = 0; + char valcp[16]; + char *s; + + strncpy(valcp, val, 15); + valcp[15] = '\0'; + + s = strstrip(valcp); + + rv = fn(s, NULL); + if (rv) + goto out; + + check_parms(); + if (watchdog_user) + rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); + + out: + return rv; +} + +static int get_param_str(char *buffer, const struct kernel_param *kp) +{ + action_fn fn = (action_fn) kp->arg; + int rv; + + rv = fn(NULL, buffer); + if (rv) + return rv; + return strlen(buffer); +} + + +static int set_param_wdog_ifnum(const char *val, const 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; +} + +static const struct kernel_param_ops param_ops_wdog_ifnum = { + .set = set_param_wdog_ifnum, + .get = param_get_int, +}; + +#define param_check_wdog_ifnum param_check_int + +static const struct kernel_param_ops param_ops_str = { + .set = set_param_str, + .get = get_param_str, +}; + +module_param(ifnum_to_use, wdog_ifnum, 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(timeout, timeout, 0644); +MODULE_PARM_DESC(timeout, "Timeout value in seconds."); + +module_param(pretimeout, timeout, 0644); +MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); + +module_param(panic_wdt_timeout, timeout, 0644); +MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds."); + +module_param_cb(action, ¶m_ops_str, action_op, 0644); +MODULE_PARM_DESC(action, "Timeout action. One of: " + "reset, none, power_cycle, power_off."); + +module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); +MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " + "pre_none, pre_smi, pre_nmi, pre_int."); + +module_param_cb(preop, ¶m_ops_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, 0444); +MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" + "soon as the driver is loaded."); + +module_param(nowayout, bool, 0644); +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; + +/* Is someone using the watchdog? Only one user is allowed. */ +static unsigned long ipmi_wdog_open; + +/* + * If set to 1, the heartbeat command will set the state to reset and + * start the timer. The timer doesn't normally run when the driver is + * first opened until the heartbeat is set the first time, this + * variable is used to accomplish this. + */ +static int ipmi_start_timer_on_heartbeat; + +/* IPMI version of the BMC. */ +static unsigned char ipmi_version_major; +static unsigned char ipmi_version_minor; + +/* If a pretimeout occurs, this is used to allow only one panic to happen. */ +static atomic_t preop_panic_excl = ATOMIC_INIT(-1); + +#ifdef HAVE_DIE_NMI +static int testing_nmi; +static int nmi_handler_registered; +#endif + +static int __ipmi_heartbeat(void); + +/* + * We use a mutex to make sure that only one thing can send a set a + * message at one time. The mutex is claimed when a message is sent + * and freed when both the send and receive messages are free. + */ +static atomic_t msg_tofree = ATOMIC_INIT(0); +static DECLARE_COMPLETION(msg_wait); +static void msg_free_smi(struct ipmi_smi_msg *msg) +{ + if (atomic_dec_and_test(&msg_tofree)) + complete(&msg_wait); +} +static void msg_free_recv(struct ipmi_recv_msg *msg) +{ + if (atomic_dec_and_test(&msg_tofree)) + complete(&msg_wait); +} +static struct ipmi_smi_msg smi_msg = { + .done = msg_free_smi +}; +static struct ipmi_recv_msg recv_msg = { + .done = msg_free_recv +}; + +static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, + struct ipmi_recv_msg *recv_msg, + int *send_heartbeat_now) +{ + struct kernel_ipmi_msg msg; + unsigned char data[6]; + int rv; + struct ipmi_system_interface_addr addr; + int hbnow = 0; + + + data[0] = 0; + WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); + + if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { + if ((ipmi_version_major > 1) || + ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { + /* This is an IPMI 1.5-only feature. */ + data[0] |= WDOG_DONT_STOP_ON_SET; + } else { + /* + * In ipmi 1.0, setting the timer stops the watchdog, we + * need to start it back up again. + */ + hbnow = 1; + } + } + + data[1] = 0; + WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); + if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { + WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); + data[2] = pretimeout; + } else { + WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); + data[2] = 0; /* No pretimeout. */ + } + data[3] = 0; + WDOG_SET_TIMEOUT(data[4], data[5], timeout); + + addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; + addr.channel = IPMI_BMC_CHANNEL; + addr.lun = 0; + + msg.netfn = 0x06; + msg.cmd = IPMI_WDOG_SET_TIMER; + msg.data = data; + msg.data_len = sizeof(data); + rv = ipmi_request_supply_msgs(watchdog_user, + (struct ipmi_addr *) &addr, + 0, + &msg, + NULL, + smi_msg, + recv_msg, + 1); + if (rv) + pr_warn(PFX "set timeout error: %d\n", rv); + else if (send_heartbeat_now) + *send_heartbeat_now = hbnow; + + return rv; +} + +static int _ipmi_set_timeout(int do_heartbeat) +{ + int send_heartbeat_now; + int rv; + + if (!watchdog_user) + return -ENODEV; + + atomic_set(&msg_tofree, 2); + + rv = __ipmi_set_timeout(&smi_msg, + &recv_msg, + &send_heartbeat_now); + if (rv) + return rv; + + wait_for_completion(&msg_wait); + + if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) + || ((send_heartbeat_now) + && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) + rv = __ipmi_heartbeat(); + + return rv; +} + +static int ipmi_set_timeout(int do_heartbeat) +{ + int rv; + + mutex_lock(&ipmi_watchdog_mutex); + rv = _ipmi_set_timeout(do_heartbeat); + mutex_unlock(&ipmi_watchdog_mutex); + + return rv; +} + +static atomic_t panic_done_count = ATOMIC_INIT(0); + +static void panic_smi_free(struct ipmi_smi_msg *msg) +{ + atomic_dec(&panic_done_count); +} +static void panic_recv_free(struct ipmi_recv_msg *msg) +{ + atomic_dec(&panic_done_count); +} + +static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { + .done = panic_smi_free +}; +static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { + .done = panic_recv_free +}; + +static void panic_halt_ipmi_heartbeat(void) +{ + struct kernel_ipmi_msg msg; + struct ipmi_system_interface_addr addr; + int rv; + + /* + * Don't reset the timer if we have the timer turned off, that + * re-enables the watchdog. + */ + if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) + return; + + addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; + addr.channel = IPMI_BMC_CHANNEL; + addr.lun = 0; + + msg.netfn = 0x06; + msg.cmd = IPMI_WDOG_RESET_TIMER; + msg.data = NULL; + msg.data_len = 0; + atomic_add(1, &panic_done_count); + rv = ipmi_request_supply_msgs(watchdog_user, + (struct ipmi_addr *) &addr, + 0, + &msg, + NULL, + &panic_halt_heartbeat_smi_msg, + &panic_halt_heartbeat_recv_msg, + 1); + if (rv) + atomic_sub(1, &panic_done_count); +} + +static struct ipmi_smi_msg panic_halt_smi_msg = { + .done = panic_smi_free +}; +static struct ipmi_recv_msg panic_halt_recv_msg = { + .done = panic_recv_free +}; + +/* + * Special call, doesn't claim any locks. This is only to be called + * at panic or halt time, in run-to-completion mode, when the caller + * is the only CPU and the only thing that will be going is these IPMI + * calls. + */ +static void panic_halt_ipmi_set_timeout(void) +{ + int send_heartbeat_now; + int rv; + + /* Wait for the messages to be free. */ + while (atomic_read(&panic_done_count) != 0) + ipmi_poll_interface(watchdog_user); + atomic_add(1, &panic_done_count); + rv = __ipmi_set_timeout(&panic_halt_smi_msg, + &panic_halt_recv_msg, + &send_heartbeat_now); + if (rv) { + atomic_sub(1, &panic_done_count); + pr_warn(PFX "Unable to extend the watchdog timeout."); + } else { + if (send_heartbeat_now) + panic_halt_ipmi_heartbeat(); + } + while (atomic_read(&panic_done_count) != 0) + ipmi_poll_interface(watchdog_user); +} + +static int __ipmi_heartbeat(void) +{ + struct kernel_ipmi_msg msg; + int rv; + struct ipmi_system_interface_addr addr; + int timeout_retries = 0; + +restart: + /* + * Don't reset the timer if we have the timer turned off, that + * re-enables the watchdog. + */ + if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) + return 0; + + atomic_set(&msg_tofree, 2); + + addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; + addr.channel = IPMI_BMC_CHANNEL; + addr.lun = 0; + + msg.netfn = 0x06; + msg.cmd = IPMI_WDOG_RESET_TIMER; + msg.data = NULL; + msg.data_len = 0; + rv = ipmi_request_supply_msgs(watchdog_user, + (struct ipmi_addr *) &addr, + 0, + &msg, + NULL, + &smi_msg, + &recv_msg, + 1); + if (rv) { + pr_warn(PFX "heartbeat send failure: %d\n", rv); + return rv; + } + + /* Wait for the heartbeat to be sent. */ + wait_for_completion(&msg_wait); + + if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) { + timeout_retries++; + if (timeout_retries > 3) { + pr_err(PFX ": Unable to restore the IPMI watchdog's settings, giving up.\n"); + rv = -EIO; + goto out; + } + + /* + * The timer was not initialized, that means the BMC was + * probably reset and lost the watchdog information. Attempt + * to restore the timer's info. Note that we still hold + * the heartbeat lock, to keep a heartbeat from happening + * in this process, so must say no heartbeat to avoid a + * deadlock on this mutex + */ + rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + if (rv) { + pr_err(PFX ": Unable to send the command to set the watchdog's settings, giving up.\n"); + goto out; + } + + /* Might need a heartbeat send, go ahead and do it. */ + goto restart; + } else if (recv_msg.msg.data[0] != 0) { + /* + * Got an error in the heartbeat response. It was already + * reported in ipmi_wdog_msg_handler, but we should return + * an error here. + */ + rv = -EINVAL; + } + +out: + return rv; +} + +static int _ipmi_heartbeat(void) +{ + int rv; + + if (!watchdog_user) + return -ENODEV; + + if (ipmi_start_timer_on_heartbeat) { + ipmi_start_timer_on_heartbeat = 0; + ipmi_watchdog_state = action_val; + rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); + } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) { + /* + * A pretimeout occurred, make sure we set the timeout. + * We don't want to set the action, though, we want to + * leave that alone (thus it can't be combined with the + * above operation. + */ + rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); + } else { + rv = __ipmi_heartbeat(); + } + + return rv; +} + +static int ipmi_heartbeat(void) +{ + int rv; + + mutex_lock(&ipmi_watchdog_mutex); + rv = _ipmi_heartbeat(); + mutex_unlock(&ipmi_watchdog_mutex); + + return rv; +} + +static struct watchdog_info ident = { + .options = 0, /* WDIOF_SETTIMEOUT, */ + .firmware_version = 1, + .identity = "IPMI" +}; + +static int ipmi_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int i; + int val; + + switch (cmd) { + case WDIOC_GETSUPPORT: + i = copy_to_user(argp, &ident, sizeof(ident)); + return i ? -EFAULT : 0; + + case WDIOC_SETTIMEOUT: + i = copy_from_user(&val, argp, sizeof(int)); + if (i) + return -EFAULT; + timeout = val; + return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); + + case WDIOC_GETTIMEOUT: + i = copy_to_user(argp, &timeout, sizeof(timeout)); + if (i) + return -EFAULT; + return 0; + + case WDIOC_SETPRETIMEOUT: + i = copy_from_user(&val, argp, sizeof(int)); + if (i) + return -EFAULT; + pretimeout = val; + return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); + + case WDIOC_GETPRETIMEOUT: + i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); + if (i) + return -EFAULT; + return 0; + + case WDIOC_KEEPALIVE: + return _ipmi_heartbeat(); + + case WDIOC_SETOPTIONS: + i = copy_from_user(&val, argp, sizeof(int)); + if (i) + return -EFAULT; + if (val & WDIOS_DISABLECARD) { + ipmi_watchdog_state = WDOG_TIMEOUT_NONE; + _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + ipmi_start_timer_on_heartbeat = 0; + } + + if (val & WDIOS_ENABLECARD) { + ipmi_watchdog_state = action_val; + _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); + } + return 0; + + case WDIOC_GETSTATUS: + val = 0; + i = copy_to_user(argp, &val, sizeof(val)); + if (i) + return -EFAULT; + return 0; + + default: + return -ENOIOCTLCMD; + } +} + +static long ipmi_unlocked_ioctl(struct file *file, + unsigned int cmd, + unsigned long arg) +{ + int ret; + + mutex_lock(&ipmi_watchdog_mutex); + ret = ipmi_ioctl(file, cmd, arg); + mutex_unlock(&ipmi_watchdog_mutex); + + return ret; +} + +static ssize_t ipmi_write(struct file *file, + const char __user *buf, + size_t len, + loff_t *ppos) +{ + int rv; + + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + rv = ipmi_heartbeat(); + if (rv) + return rv; + } + return len; +} + +static ssize_t ipmi_read(struct file *file, + char __user *buf, + size_t count, + loff_t *ppos) +{ + int rv = 0; + wait_queue_entry_t wait; + + if (count <= 0) + return 0; + + /* + * Reading returns if the pretimeout has gone off, and it only does + * it once per pretimeout. + */ + spin_lock_irq(&ipmi_read_lock); + if (!data_to_read) { + if (file->f_flags & O_NONBLOCK) { + rv = -EAGAIN; + goto out; + } + + init_waitqueue_entry(&wait, current); + add_wait_queue(&read_q, &wait); + while (!data_to_read) { + set_current_state(TASK_INTERRUPTIBLE); + spin_unlock_irq(&ipmi_read_lock); + schedule(); + spin_lock_irq(&ipmi_read_lock); + } + remove_wait_queue(&read_q, &wait); + + if (signal_pending(current)) { + rv = -ERESTARTSYS; + goto out; + } + } + data_to_read = 0; + + out: + spin_unlock_irq(&ipmi_read_lock); + + if (rv == 0) { + if (copy_to_user(buf, &data_to_read, 1)) + rv = -EFAULT; + else + rv = 1; + } + + return rv; +} + +static int ipmi_open(struct inode *ino, struct file *filep) +{ + switch (iminor(ino)) { + case WATCHDOG_MINOR: + if (test_and_set_bit(0, &ipmi_wdog_open)) + return -EBUSY; + + + /* + * Don't start the timer now, let it start on the + * first heartbeat. + */ + ipmi_start_timer_on_heartbeat = 1; + return nonseekable_open(ino, filep); + + default: + return (-ENODEV); + } +} + +static __poll_t ipmi_poll(struct file *file, poll_table *wait) +{ + __poll_t mask = 0; + + poll_wait(file, &read_q, wait); + + spin_lock_irq(&ipmi_read_lock); + if (data_to_read) + mask |= (EPOLLIN | EPOLLRDNORM); + spin_unlock_irq(&ipmi_read_lock); + + return mask; +} + +static int ipmi_fasync(int fd, struct file *file, int on) +{ + int result; + + result = fasync_helper(fd, file, on, &fasync_q); + + return (result); +} + +static int ipmi_close(struct inode *ino, struct file *filep) +{ + if (iminor(ino) == WATCHDOG_MINOR) { + if (expect_close == 42) { + mutex_lock(&ipmi_watchdog_mutex); + ipmi_watchdog_state = WDOG_TIMEOUT_NONE; + _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + mutex_unlock(&ipmi_watchdog_mutex); + } else { + pr_crit(PFX + "Unexpected close, not stopping watchdog!\n"); + ipmi_heartbeat(); + } + clear_bit(0, &ipmi_wdog_open); + } + + expect_close = 0; + + return 0; +} + +static const struct file_operations ipmi_wdog_fops = { + .owner = THIS_MODULE, + .read = ipmi_read, + .poll = ipmi_poll, + .write = ipmi_write, + .unlocked_ioctl = ipmi_unlocked_ioctl, + .open = ipmi_open, + .release = ipmi_close, + .fasync = ipmi_fasync, + .llseek = no_llseek, +}; + +static struct miscdevice ipmi_wdog_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ipmi_wdog_fops +}; + +static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, + void *handler_data) +{ + if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER && + msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) + pr_info(PFX "response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n"); + else if (msg->msg.data[0] != 0) + pr_err(PFX "response: Error %x on cmd %x\n", + msg->msg.data[0], + msg->msg.cmd); + + ipmi_free_recv_msg(msg); +} + +static void ipmi_wdog_pretimeout_handler(void *handler_data) +{ + if (preaction_val != WDOG_PRETIMEOUT_NONE) { + if (preop_val == WDOG_PREOP_PANIC) { + if (atomic_inc_and_test(&preop_panic_excl)) + panic("Watchdog pre-timeout"); + } else if (preop_val == WDOG_PREOP_GIVE_DATA) { + unsigned long flags; + + spin_lock_irqsave(&ipmi_read_lock, flags); + data_to_read = 1; + wake_up_interruptible(&read_q); + kill_fasync(&fasync_q, SIGIO, POLL_IN); + spin_unlock_irqrestore(&ipmi_read_lock, flags); + } + } + + /* + * On some machines, the heartbeat will give an error and not + * work unless we re-enable the timer. So do so. + */ + atomic_set(&pretimeout_since_last_heartbeat, 1); +} + +static void ipmi_wdog_panic_handler(void *user_data) +{ + static int panic_event_handled; + + /* + * On a panic, if we have a panic timeout, make sure to extend + * the watchdog timer to a reasonable value to complete the + * panic, if the watchdog timer is running. Plus the + * pretimeout is meaningless at panic time. + */ + if (watchdog_user && !panic_event_handled && + ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { + /* Make sure we do this only once. */ + panic_event_handled = 1; + + timeout = panic_wdt_timeout; + pretimeout = 0; + panic_halt_ipmi_set_timeout(); + } +} + +static const struct ipmi_user_hndl ipmi_hndlrs = { + .ipmi_recv_hndl = ipmi_wdog_msg_handler, + .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler, + .ipmi_panic_handler = ipmi_wdog_panic_handler +}; + +static void ipmi_register_watchdog(int ipmi_intf) +{ + int rv = -EBUSY; + + 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) { + pr_crit(PFX "Unable to register with ipmi\n"); + goto out; + } + + rv = ipmi_get_version(watchdog_user, + &ipmi_version_major, + &ipmi_version_minor); + if (rv) { + pr_warn(PFX "Unable to get IPMI version, assuming 1.0\n"); + ipmi_version_major = 1; + ipmi_version_minor = 0; + } + + rv = misc_register(&ipmi_wdog_miscdev); + if (rv < 0) { + ipmi_destroy_user(watchdog_user); + watchdog_user = NULL; + pr_crit(PFX "Unable to register misc device\n"); + } + +#ifdef HAVE_DIE_NMI + if (nmi_handler_registered) { + int old_pretimeout = pretimeout; + int old_timeout = timeout; + int old_preop_val = preop_val; + + /* + * Set the pretimeout to go off in a second and give + * ourselves plenty of time to stop the timer. + */ + ipmi_watchdog_state = WDOG_TIMEOUT_RESET; + preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ + pretimeout = 99; + timeout = 100; + + testing_nmi = 1; + + rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); + if (rv) { + pr_warn(PFX "Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n", + rv); + rv = 0; + goto out_restore; + } + + msleep(1500); + + if (testing_nmi != 2) { + pr_warn(PFX "IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n"); + } + out_restore: + testing_nmi = 0; + preop_val = old_preop_val; + pretimeout = old_pretimeout; + timeout = old_timeout; + } +#endif + + out: + if ((start_now) && (rv == 0)) { + /* Run from startup, so start the timer now. */ + start_now = 0; /* Disable this function after first startup. */ + ipmi_watchdog_state = action_val; + ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); + pr_info(PFX "Starting now!\n"); + } else { + /* Stop the timer now. */ + ipmi_watchdog_state = WDOG_TIMEOUT_NONE; + ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + } +} + +static void ipmi_unregister_watchdog(int ipmi_intf) +{ + int rv; + struct ipmi_user *loc_user = watchdog_user; + + if (!loc_user) + return; + + if (watchdog_ifnum != ipmi_intf) + return; + + /* Make sure no one can call us any more. */ + misc_deregister(&ipmi_wdog_miscdev); + + watchdog_user = NULL; + + /* + * 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(&msg_tofree)) + msg_free_smi(NULL); + + mutex_lock(&ipmi_watchdog_mutex); + + /* Disconnect from IPMI. */ + rv = ipmi_destroy_user(loc_user); + if (rv) + pr_warn(PFX "error unlinking from IPMI: %d\n", rv); + + /* If it comes back, restart it properly. */ + ipmi_start_timer_on_heartbeat = 1; + + mutex_unlock(&ipmi_watchdog_mutex); +} + +#ifdef HAVE_DIE_NMI +static int +ipmi_nmi(unsigned int val, struct pt_regs *regs) +{ + /* + * If we get here, it's an NMI that's not a memory or I/O + * error. We can't truly tell if it's from IPMI or not + * without sending a message, and sending a message is almost + * impossible because of locking. + */ + + if (testing_nmi) { + testing_nmi = 2; + return NMI_HANDLED; + } + + /* If we are not expecting a timeout, ignore it. */ + if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) + return NMI_DONE; + + if (preaction_val != WDOG_PRETIMEOUT_NMI) + return NMI_DONE; + + /* + * If no one else handled the NMI, we assume it was the IPMI + * watchdog. + */ + if (preop_val == WDOG_PREOP_PANIC) { + /* On some machines, the heartbeat will give + an error and not work unless we re-enable + the timer. So do so. */ + atomic_set(&pretimeout_since_last_heartbeat, 1); + if (atomic_inc_and_test(&preop_panic_excl)) + nmi_panic(regs, PFX "pre-timeout"); + } + + return NMI_HANDLED; +} +#endif + +static int wdog_reboot_handler(struct notifier_block *this, + unsigned long code, + void *unused) +{ + static int reboot_event_handled; + + if ((watchdog_user) && (!reboot_event_handled)) { + /* Make sure we only do this once. */ + reboot_event_handled = 1; + + if (code == SYS_POWER_OFF || code == SYS_HALT) { + /* Disable the WDT if we are shutting down. */ + ipmi_watchdog_state = WDOG_TIMEOUT_NONE; + ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { + /* Set a long timer to let the reboot happen or + reset if it hangs, but only if the watchdog + timer was already running. */ + if (timeout < 120) + timeout = 120; + pretimeout = 0; + ipmi_watchdog_state = WDOG_TIMEOUT_RESET; + ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); + } + } + return NOTIFY_OK; +} + +static struct notifier_block wdog_reboot_notifier = { + .notifier_call = wdog_reboot_handler, + .next = NULL, + .priority = 0 +}; + +static void ipmi_new_smi(int if_num, struct device *device) +{ + ipmi_register_watchdog(if_num); +} + +static void ipmi_smi_gone(int if_num) +{ + ipmi_unregister_watchdog(if_num); +} + +static struct ipmi_smi_watcher smi_watcher = { + .owner = THIS_MODULE, + .new_smi = ipmi_new_smi, + .smi_gone = ipmi_smi_gone +}; + +static int action_op(const char *inval, char *outval) +{ + if (outval) + strcpy(outval, action); + + if (!inval) + return 0; + + if (strcmp(inval, "reset") == 0) + action_val = WDOG_TIMEOUT_RESET; + else if (strcmp(inval, "none") == 0) + action_val = WDOG_TIMEOUT_NONE; + else if (strcmp(inval, "power_cycle") == 0) + action_val = WDOG_TIMEOUT_POWER_CYCLE; + else if (strcmp(inval, "power_off") == 0) + action_val = WDOG_TIMEOUT_POWER_DOWN; + else + return -EINVAL; + strcpy(action, inval); + return 0; +} + +static int preaction_op(const char *inval, char *outval) +{ + if (outval) + strcpy(outval, preaction); + + if (!inval) + return 0; + + if (strcmp(inval, "pre_none") == 0) + preaction_val = WDOG_PRETIMEOUT_NONE; + else if (strcmp(inval, "pre_smi") == 0) + preaction_val = WDOG_PRETIMEOUT_SMI; +#ifdef HAVE_DIE_NMI + else if (strcmp(inval, "pre_nmi") == 0) + preaction_val = WDOG_PRETIMEOUT_NMI; +#endif + else if (strcmp(inval, "pre_int") == 0) + preaction_val = WDOG_PRETIMEOUT_MSG_INT; + else + return -EINVAL; + strcpy(preaction, inval); + return 0; +} + +static int preop_op(const char *inval, char *outval) +{ + if (outval) + strcpy(outval, preop); + + if (!inval) + return 0; + + if (strcmp(inval, "preop_none") == 0) + preop_val = WDOG_PREOP_NONE; + else if (strcmp(inval, "preop_panic") == 0) + preop_val = WDOG_PREOP_PANIC; + else if (strcmp(inval, "preop_give_data") == 0) + preop_val = WDOG_PREOP_GIVE_DATA; + else + return -EINVAL; + strcpy(preop, inval); + return 0; +} + +static void check_parms(void) +{ +#ifdef HAVE_DIE_NMI + int do_nmi = 0; + int rv; + + if (preaction_val == WDOG_PRETIMEOUT_NMI) { + do_nmi = 1; + if (preop_val == WDOG_PREOP_GIVE_DATA) { + pr_warn(PFX "Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n"); + preop_op("preop_none", NULL); + do_nmi = 0; + } + } + if (do_nmi && !nmi_handler_registered) { + rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0, + "ipmi"); + if (rv) { + pr_warn(PFX "Can't register nmi handler\n"); + return; + } else + nmi_handler_registered = 1; + } else if (!do_nmi && nmi_handler_registered) { + unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); + nmi_handler_registered = 0; + } +#endif +} + +static int __init ipmi_wdog_init(void) +{ + int rv; + + if (action_op(action, NULL)) { + action_op("reset", NULL); + pr_info(PFX "Unknown action '%s', defaulting to reset\n", + action); + } + + if (preaction_op(preaction, NULL)) { + preaction_op("pre_none", NULL); + pr_info(PFX "Unknown preaction '%s', defaulting to none\n", + preaction); + } + + if (preop_op(preop, NULL)) { + preop_op("preop_none", NULL); + pr_info(PFX "Unknown preop '%s', defaulting to none\n", preop); + } + + check_parms(); + + register_reboot_notifier(&wdog_reboot_notifier); + + rv = ipmi_smi_watcher_register(&smi_watcher); + if (rv) { +#ifdef HAVE_DIE_NMI + if (nmi_handler_registered) + unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); +#endif + unregister_reboot_notifier(&wdog_reboot_notifier); + pr_warn(PFX "can't register smi watcher\n"); + return rv; + } + + pr_info(PFX "driver initialized\n"); + + return 0; +} + +static void __exit ipmi_wdog_exit(void) +{ + ipmi_smi_watcher_unregister(&smi_watcher); + ipmi_unregister_watchdog(watchdog_ifnum); + +#ifdef HAVE_DIE_NMI + if (nmi_handler_registered) + unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); +#endif + + unregister_reboot_notifier(&wdog_reboot_notifier); +} +module_exit(ipmi_wdog_exit); +module_init(ipmi_wdog_init); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); +MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface."); |