[PATCH] ipmi: add power cycle capability

This patch to adds "power cycle" functionality to the IPMI power off module
ipmi_poweroff.  It also contains changes to support procfs control of the
feature.

The power cycle action is considered an optional chassis control in the IPMI
specification.  However, it is definitely useful when the hardware supports
it.  A power cycle is usually required in order to reset a firmware in a bad
state.  This action is critical to allow remote management of servers.

The implementation adds power cycle as optional to the ipmi_poweroff module.
It can be modified dynamically through the proc entry mentioned above.  During
a power down and enabled, the power cycle command is sent to the BMC firmware.
 If it fails either due to non-support or some error, it will retry to send
the command as power off.

Signed-off-by: Christopher A. Poblete <Chris_Poblete@dell.com>
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 103 insertions, 9 deletions

diff --git a/drivers/char/ipmi/ipmi_poweroff.c b/drivers/char/ipmi/ipmi_poweroff.c
index cb5cdc6f14bf..61329b55c4a9 100644
--- a/drivers/char/ipmi/ipmi_poweroff.c
+++ b/drivers/char/ipmi/ipmi_poweroff.c
@@ -34,6 +34,8 @@
 #include <asm/semaphore.h>
 #include <linux/kdev_t.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/proc_fs.h>
 #include <linux/string.h>
 #include <linux/ipmi.h>
 #include <linux/ipmi_smi.h>
@@ -44,6 +46,18 @@
 /* Where to we insert our poweroff function? */
 extern void (*pm_power_off)(void);
 
+/* Definitions for controlling power off (if the system supports it).  It
+ * conveniently matches the IPMI chassis control values. */
+#define IPMI_CHASSIS_POWER_DOWN         0       /* power down, the default. */
+#define IPMI_CHASSIS_POWER_CYCLE        0x02    /* power cycle */
+
+/* the IPMI data command */
+static int poweroff_control = IPMI_CHASSIS_POWER_DOWN;
+
+/* parameter definition to allow user to flag power cycle */
+module_param(poweroff_control, int, IPMI_CHASSIS_POWER_DOWN);
+MODULE_PARM_DESC(poweroff_control, " Set to 2 to enable power cycle instead of power down. Power cycle is contingent on hardware support, otherwise it defaults back to power down.");
+
 /* Stuff from the get device id command. */
 static unsigned int mfg_id;
 static unsigned int prod_id;
@@ -349,26 +363,38 @@ static void ipmi_poweroff_chassis (ipmi_user_t user)
         smi_addr.channel = IPMI_BMC_CHANNEL;
         smi_addr.lun = 0;
 
-        printk(KERN_INFO PFX "Powering down via IPMI chassis control command\n");
+ powercyclefailed:
+        printk(KERN_INFO PFX "Powering %s via IPMI chassis control command\n",
+                ((poweroff_control != IPMI_CHASSIS_POWER_CYCLE) ? "down" : "cycle"));
 
         /*
          * Power down
          */
         send_msg.netfn = IPMI_NETFN_CHASSIS_REQUEST;
         send_msg.cmd = IPMI_CHASSIS_CONTROL_CMD;
-        data[0] = 0; /* Power down */
+        data[0] = poweroff_control;
         send_msg.data = data;
         send_msg.data_len = sizeof(data);
         rv = ipmi_request_in_rc_mode(user,
                                      (struct ipmi_addr *) &smi_addr,
                                      &send_msg);
         if (rv) {
-                printk(KERN_ERR PFX "Unable to send chassis powerdown message,"
-                       " IPMI error 0x%x\n", rv);
-                goto out;
+                switch (poweroff_control) {
+                        case IPMI_CHASSIS_POWER_CYCLE:
+                                /* power cycle failed, default to power down */
+                                printk(KERN_ERR PFX "Unable to send chassis power " \
+                                        "cycle message, IPMI error 0x%x\n", rv);
+                                poweroff_control = IPMI_CHASSIS_POWER_DOWN;
+                                goto powercyclefailed;
+
+                        case IPMI_CHASSIS_POWER_DOWN:
+                        default:
+                                printk(KERN_ERR PFX "Unable to send chassis power " \
+                                        "down message, IPMI error 0x%x\n", rv);
+                                break;
+                }
         }
 
- out:
         return;
 }
 
@@ -430,7 +456,8 @@ static void ipmi_po_new_smi(int if_num)
         if (ready)
                 return;
 
-        rv = ipmi_create_user(if_num, &ipmi_poweroff_handler, NULL, &ipmi_user);
+        rv = ipmi_create_user(if_num, &ipmi_poweroff_handler, NULL,
+                              &ipmi_user);
         if (rv) {
                 printk(KERN_ERR PFX "could not create IPMI user, error %d\n",
                        rv);
@@ -509,21 +536,84 @@ static struct ipmi_smi_watcher smi_watcher =
 };
 
 
+#ifdef CONFIG_PROC_FS
+/* displays properties to proc */
+static int proc_read_chassctrl(char *page, char **start, off_t off, int count,
+                               int *eof, void *data)
+{
+        return sprintf(page, "%d\t[ 0=powerdown 2=powercycle ]\n",
+                        poweroff_control);
+}
+
+/* process property writes from proc */
+static int proc_write_chassctrl(struct file *file, const char *buffer,
+                                unsigned long count, void *data)
+{
+        int          rv = count;
+        unsigned int newval = 0;
+
+        sscanf(buffer, "%d", &newval);
+        switch (newval) {
+                case IPMI_CHASSIS_POWER_CYCLE:
+                        printk(KERN_INFO PFX "power cycle is now enabled\n");
+                        poweroff_control = newval;
+                        break;
+
+                case IPMI_CHASSIS_POWER_DOWN:
+                        poweroff_control = IPMI_CHASSIS_POWER_DOWN;
+                        break;
+
+                default:
+                        rv = -EINVAL;
+                        break;
+        }
+
+        return rv;
+}
+#endif /* CONFIG_PROC_FS */
+
 /*
  * Startup and shutdown functions.
  */
 static int ipmi_poweroff_init (void)
 {
-        int rv;
+        int                   rv;
+        struct proc_dir_entry *file;
 
         printk ("Copyright (C) 2004 MontaVista Software -"
                 " IPMI Powerdown via sys_reboot version "
                 IPMI_POWEROFF_VERSION ".\n");
 
+        switch (poweroff_control) {
+                case IPMI_CHASSIS_POWER_CYCLE:
+                        printk(KERN_INFO PFX "Power cycle is enabled.\n");
+                        break;
+
+                case IPMI_CHASSIS_POWER_DOWN:
+                default:
+                        poweroff_control = IPMI_CHASSIS_POWER_DOWN;
+                        break;
+        }
+
         rv = ipmi_smi_watcher_register(&smi_watcher);
-        if (rv)
+        if (rv) {
                 printk(KERN_ERR PFX "Unable to register SMI watcher: %d\n", rv);
+                goto out_err;
+        }
+
+#ifdef CONFIG_PROC_FS
+        file = create_proc_entry("poweroff_control", 0, proc_ipmi_root);
+        if (!file) {
+                printk(KERN_ERR PFX "Unable to create proc power control\n");
+        } else {
+                file->nlink = 1;
+                file->read_proc = proc_read_chassctrl;
+                file->write_proc = proc_write_chassctrl;
+                file->owner = THIS_MODULE;
+        }
+#endif
 
+ out_err:
         return rv;
 }
 
@@ -532,6 +622,10 @@ static __exit void ipmi_poweroff_cleanup(void)
 {
         int rv;
 
+#ifdef CONFIG_PROC_FS
+        remove_proc_entry("poweroff_control", proc_ipmi_root);
+#endif
+
         ipmi_smi_watcher_unregister(&smi_watcher);
 
         if (ready) {