[PATCH] ipmi: watchdog parms in sysfs

Modify the IPMI watchdog parameters (the ones that make sense) to be exported
from sysfs.  This is somewhat complicated because these parameters have
side-effects that must be handled.

Signed-off-by: Corey Minyard <minyard@acm.org>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 196 insertions, 50 deletions

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 2da64bf7469c..405697a9f4d9 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -47,6 +47,8 @@
 #include <linux/reboot.h>
 #include <linux/wait.h>
 #include <linux/poll.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/apic.h>
 #endif
@@ -158,27 +160,120 @@ static struct fasync_struct *fasync_q = NULL;
 static char pretimeout_since_last_heartbeat = 0;
 static char expect_close;
 
+static DECLARE_RWSEM(register_sem);
+
+/* 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);
+
 /* If true, the driver will start running as soon as it is configured
    and ready. */
 static int start_now = 0;
 
-module_param(timeout, int, 0);
+static int set_param_int(const char *val, 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;
+
+        down_read(&register_sem);
+        *((int *)kp->arg) = l;
+        if (watchdog_user)
+                rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+        up_read(&register_sem);
+
+        return rv;
+}
+
+static int get_param_int(char *buffer, struct kernel_param *kp)
+{
+        return sprintf(buffer, "%i", *((int *)kp->arg));
+}
+
+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, struct kernel_param *kp)
+{
+        action_fn  fn = (action_fn) kp->arg;
+        int        rv = 0;
+        const char *end;
+        char       valcp[16];
+        int        len;
+
+        /* Truncate leading and trailing spaces. */
+        while (isspace(*val))
+                val++;
+        end = val + strlen(val) - 1;
+        while ((end >= val) && isspace(*end))
+                end--;
+        len = end - val + 1;
+        if (len > sizeof(valcp) - 1)
+                return -EINVAL;
+        memcpy(valcp, val, len);
+        valcp[len] = '\0';
+
+        down_read(&register_sem);
+        rv = fn(valcp, NULL);
+        if (rv)
+                goto out_unlock;
+
+        check_parms();
+        if (watchdog_user)
+                rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+
+ out_unlock:
+        up_read(&register_sem);
+        return rv;
+}
+
+static int get_param_str(char *buffer, struct kernel_param *kp)
+{
+        action_fn fn = (action_fn) kp->arg;
+        int       rv;
+
+        rv = fn(NULL, buffer);
+        if (rv)
+                return rv;
+        return strlen(buffer);
+}
+
+module_param_call(timeout, set_param_int, get_param_int, &timeout, 0644);
 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
-module_param(pretimeout, int, 0);
+
+module_param_call(pretimeout, set_param_int, get_param_int, &pretimeout, 0644);
 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
-module_param_string(action, action, sizeof(action), 0);
+
+module_param_call(action, set_param_str, get_param_str, action_op, 0644);
 MODULE_PARM_DESC(action, "Timeout action. One of: "
                  "reset, none, power_cycle, power_off.");
-module_param_string(preaction, preaction, sizeof(preaction), 0);
+
+module_param_call(preaction, set_param_str, get_param_str, preaction_op, 0644);
 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
                  "pre_none, pre_smi, pre_nmi, pre_int.");
-module_param_string(preop, preop, sizeof(preop), 0);
+
+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_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
                  "soon as the driver is loaded.");
-module_param(nowayout, int, 0);
+
+module_param(nowayout, int, 0644);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 
 /* Default state of the timer. */
@@ -294,11 +389,6 @@ static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
         return rv;
 }
 
-/* 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)
 {
         int send_heartbeat_now;
@@ -732,8 +822,6 @@ static struct miscdevice ipmi_wdog_miscdev = {
         .fops           = &ipmi_wdog_fops
 };
 
-static DECLARE_RWSEM(register_sem);
-
 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
                                   void                 *handler_data)
 {
@@ -839,6 +927,7 @@ static struct nmi_handler ipmi_nmi_handler =
         .handler  = ipmi_nmi,
         .priority = 0, /* Call us last. */
 };
+int nmi_handler_registered;
 #endif
 
 static int wdog_reboot_handler(struct notifier_block *this,
@@ -921,59 +1010,86 @@ static struct ipmi_smi_watcher smi_watcher =
         .smi_gone = ipmi_smi_gone
 };
 
-static int __init ipmi_wdog_init(void)
+static int action_op(const char *inval, char *outval)
 {
-        int rv;
+        if (outval)
+                strcpy(outval, action);
+
+        if (!inval)
+                return 0;
 
-        if (strcmp(action, "reset") == 0) {
+        if (strcmp(inval, "reset") == 0)
                 action_val = WDOG_TIMEOUT_RESET;
-        } else if (strcmp(action, "none") == 0) {
+        else if (strcmp(inval, "none") == 0)
                 action_val = WDOG_TIMEOUT_NONE;
-        } else if (strcmp(action, "power_cycle") == 0) {
+        else if (strcmp(inval, "power_cycle") == 0)
                 action_val = WDOG_TIMEOUT_POWER_CYCLE;
-        } else if (strcmp(action, "power_off") == 0) {
+        else if (strcmp(inval, "power_off") == 0)
                 action_val = WDOG_TIMEOUT_POWER_DOWN;
-        } else {
-                action_val = WDOG_TIMEOUT_RESET;
-                printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
-                       " reset\n", action);
-        }
+        else
+                return -EINVAL;
+        strcpy(action, inval);
+        return 0;
+}
+
+static int preaction_op(const char *inval, char *outval)
+{
+        if (outval)
+                strcpy(outval, preaction);
 
-        if (strcmp(preaction, "pre_none") == 0) {
+        if (!inval)
+                return 0;
+
+        if (strcmp(inval, "pre_none") == 0)
                 preaction_val = WDOG_PRETIMEOUT_NONE;
-        } else if (strcmp(preaction, "pre_smi") == 0) {
+        else if (strcmp(inval, "pre_smi") == 0)
                 preaction_val = WDOG_PRETIMEOUT_SMI;
 #ifdef HAVE_NMI_HANDLER
-        } else if (strcmp(preaction, "pre_nmi") == 0) {
+        else if (strcmp(inval, "pre_nmi") == 0)
                 preaction_val = WDOG_PRETIMEOUT_NMI;
 #endif
-        } else if (strcmp(preaction, "pre_int") == 0) {
+        else if (strcmp(inval, "pre_int") == 0)
                 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
-        } else {
-                preaction_val = WDOG_PRETIMEOUT_NONE;
-                printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
-                       " none\n", preaction);
-        }
+        else
+                return -EINVAL;
+        strcpy(preaction, inval);
+        return 0;
+}
+
+static int preop_op(const char *inval, char *outval)
+{
+        if (outval)
+                strcpy(outval, preop);
 
-        if (strcmp(preop, "preop_none") == 0) {
+        if (!inval)
+                return 0;
+
+        if (strcmp(inval, "preop_none") == 0)
                 preop_val = WDOG_PREOP_NONE;
-        } else if (strcmp(preop, "preop_panic") == 0) {
+        else if (strcmp(inval, "preop_panic") == 0)
                 preop_val = WDOG_PREOP_PANIC;
-        } else if (strcmp(preop, "preop_give_data") == 0) {
+        else if (strcmp(inval, "preop_give_data") == 0)
                 preop_val = WDOG_PREOP_GIVE_DATA;
-        } else {
-                preop_val = WDOG_PREOP_NONE;
-                printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
-                       " none\n", preop);
-        }
+        else
+                return -EINVAL;
+        strcpy(preop, inval);
+        return 0;
+}
 
+static void check_parms(void)
+{
 #ifdef HAVE_NMI_HANDLER
+        int do_nmi = 0;
+        int rv;
+
         if (preaction_val == WDOG_PRETIMEOUT_NMI) {
+                do_nmi = 1;
                 if (preop_val == WDOG_PREOP_GIVE_DATA) {
                         printk(KERN_WARNING PFX "Pretimeout op is to give data"
                                " but NMI pretimeout is enabled, setting"
                                " pretimeout op to none\n");
-                        preop_val = WDOG_PREOP_NONE;
+                        preop_op("preop_none", NULL);
+                        do_nmi = 0;
                 }
 #ifdef CONFIG_X86_LOCAL_APIC
                 if (nmi_watchdog == NMI_IO_APIC) {
@@ -983,18 +1099,48 @@ static int __init ipmi_wdog_init(void)
                                " Disabling IPMI nmi pretimeout.\n",
                                nmi_watchdog);
                         preaction_val = WDOG_PRETIMEOUT_NONE;
-                } else {
+                        do_nmi = 0;
+                }
 #endif
+        }
+        if (do_nmi && !nmi_handler_registered) {
                 rv = request_nmi(&ipmi_nmi_handler);
                 if (rv) {
-                        printk(KERN_WARNING PFX "Can't register nmi handler\n");
-                        return rv;
-                }
-#ifdef CONFIG_X86_LOCAL_APIC
-                }
-#endif
+                        printk(KERN_WARNING PFX
+                               "Can't register nmi handler\n");
+                        return;
+                } else
+                        nmi_handler_registered = 1;
+        } else if (!do_nmi && nmi_handler_registered) {
+                release_nmi(&ipmi_nmi_handler);
+                nmi_handler_registered = 0;
         }
 #endif
+}
+
+static int __init ipmi_wdog_init(void)
+{
+        int rv;
+
+        if (action_op(action, NULL)) {
+                action_op("reset", NULL);
+                printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
+                       " reset\n", action);
+        }
+
+        if (preaction_op(preaction, NULL)) {
+                preaction_op("pre_none", NULL);
+                printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
+                       " none\n", preaction);
+        }
+
+        if (preop_op(preop, NULL)) {
+                preop_op("preop_none", NULL);
+                printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
+                       " none\n", preop);
+        }
+
+        check_parms();
 
         rv = ipmi_smi_watcher_register(&smi_watcher);
         if (rv) {
@@ -1021,7 +1167,7 @@ static __exit void ipmi_unregister_watchdog(void)
         down_write(&register_sem);
 
 #ifdef HAVE_NMI_HANDLER
-        if (preaction_val == WDOG_PRETIMEOUT_NMI)
+        if (nmi_handler_registered)
                 release_nmi(&ipmi_nmi_handler);
 #endif