summaryrefslogtreecommitdiffstats
path: root/drivers/char/ipmi/ipmi_watchdog.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/ipmi/ipmi_watchdog.c')
-rw-r--r--drivers/char/ipmi/ipmi_watchdog.c1344
1 files changed, 1344 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..5b4e67792
--- /dev/null
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -0,0 +1,1344 @@
+// 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.
+ */
+
+#define pr_fmt(fmt) "IPMI Watchdog: " fmt
+
+#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
+
+/*
+ * 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, len;
+
+ rv = fn(NULL, buffer);
+ if (rv)
+ return rv;
+
+ len = strlen(buffer);
+ buffer[len++] = '\n';
+ buffer[len] = 0;
+
+ return len;
+}
+
+
+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, &param_ops_str, action_op, 0644);
+MODULE_PARM_DESC(action, "Timeout action. One of: "
+ "reset, none, power_cycle, power_off.");
+
+module_param_cb(preaction, &param_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, &param_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)) {
+ if (!oops_in_progress)
+ complete(&msg_wait);
+ }
+}
+static void msg_free_recv(struct ipmi_recv_msg *msg)
+{
+ if (atomic_dec_and_test(&msg_tofree)) {
+ if (!oops_in_progress)
+ complete(&msg_wait);
+ }
+}
+static struct ipmi_smi_msg smi_msg = INIT_IPMI_SMI_MSG(msg_free_smi);
+static struct ipmi_recv_msg recv_msg = INIT_IPMI_RECV_MSG(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("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) {
+ atomic_set(&msg_tofree, 0);
+ 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 =
+ INIT_IPMI_SMI_MSG(panic_smi_free);
+static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
+ INIT_IPMI_RECV_MSG(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(2, &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(2, &panic_done_count);
+}
+
+static struct ipmi_smi_msg panic_halt_smi_msg =
+ INIT_IPMI_SMI_MSG(panic_smi_free);
+static struct ipmi_recv_msg panic_halt_recv_msg =
+ INIT_IPMI_RECV_MSG(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(2, &panic_done_count);
+ rv = __ipmi_set_timeout(&panic_halt_smi_msg,
+ &panic_halt_recv_msg,
+ &send_heartbeat_now);
+ if (rv) {
+ atomic_sub(2, &panic_done_count);
+ pr_warn("Unable to extend the watchdog timeout\n");
+ } 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) {
+ atomic_set(&msg_tofree, 0);
+ pr_warn("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("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("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 const 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 stream_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("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,
+ .compat_ioctl = compat_ptr_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("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("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("Unable to register with ipmi\n");
+ goto out;
+ }
+
+ rv = ipmi_get_version(watchdog_user,
+ &ipmi_version_major,
+ &ipmi_version_minor);
+ if (rv) {
+ pr_warn("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("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("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("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("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("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, "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("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("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("Unknown action '%s', defaulting to reset\n", action);
+ }
+
+ if (preaction_op(preaction, NULL)) {
+ preaction_op("pre_none", NULL);
+ pr_info("Unknown preaction '%s', defaulting to none\n",
+ preaction);
+ }
+
+ if (preop_op(preop, NULL)) {
+ preop_op("preop_none", NULL);
+ pr_info("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("can't register smi watcher\n");
+ return rv;
+ }
+
+ pr_info("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.");