[IA64-SGI] Handle SC env. powerdown events

Handle system controller power down pending events
on SN systems. This allows the system to gracefully shutdown
before the system controller removes power due to
an adverse environmental condition.
Signed-off-by: Aaron Young <ayoung@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

drivers/char/snsc.h

@@ -5,7 +5,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2004 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2004-2006 Silicon Graphics, Inc. All rights reserved.
  */
 
 /*
@@ -70,6 +70,9 @@ struct sysctl_data_s {
 #define EV_CLASS_TEST_WARNING	0x6000ul
 #define EV_CLASS_PWRD_NOTIFY	0x8000ul
 
+/* ENV class codes */
+#define ENV_PWRDN_PEND		0x4101ul
+
 #define EV_SEVERITY_POWER_STABLE	0x0000ul
 #define EV_SEVERITY_POWER_LOW_WARNING	0x0100ul
 #define EV_SEVERITY_POWER_HIGH_WARNING	0x0200ul

drivers/char/snsc_event.c

@@ -5,7 +5,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2004 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2004-2006 Silicon Graphics, Inc. All rights reserved.
  */
 
 /*
@@ -187,7 +187,8 @@ scdrv_event_severity(int code)
 static void
 scdrv_dispatch_event(char *event, int len)
 {
-	int code, esp_code, src;
+	static int snsc_shutting_down = 0;
+	int code, esp_code, src, class;
 	char desc[CHUNKSIZE];
 	char *severity;
 
@@ -199,9 +200,25 @@ scdrv_dispatch_event(char *event, int len)
 	/* how urgent is the message? */
 	severity = scdrv_event_severity(code);
 
-	if ((code & EV_CLASS_MASK) == EV_CLASS_PWRD_NOTIFY) {
+	class = (code & EV_CLASS_MASK);
+
+	if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
 		struct task_struct *p;
 
+		if (snsc_shutting_down)
+			return;
+
+		snsc_shutting_down = 1;
+
+		/* give a message for each type of event */
+		if (class == EV_CLASS_PWRD_NOTIFY)
+			printk(KERN_NOTICE "Power off indication received."
+			       " Sending SIGPWR to init...\n");
+		else if (code == ENV_PWRDN_PEND)
+			printk(KERN_CRIT "WARNING: Shutting down the system"
+			       " due to a critical environmental condition."
+			       " Sending SIGPWR to init...\n");
+
 		/* give a SIGPWR signal to init proc */
 
 		/* first find init's task */
@@ -210,12 +227,11 @@ scdrv_dispatch_event(char *event, int len)
 			if (p->pid == 1)
 				break;
 		}
-		if (p) { /* we found init's task */
-			printk(KERN_EMERG "Power off indication received. Initiating power fail sequence...\n");
+		if (p) {
 			force_sig(SIGPWR, p);
-		} else { /* failed to find init's task - just give message(s) */
-			printk(KERN_WARNING "Failed to find init proc to handle power off!\n");
-			printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
+		} else {
+			printk(KERN_ERR "Failed to signal init!\n");
+			snsc_shutting_down = 0; /* so can try again (?) */
 		}
 		read_unlock(&tasklist_lock);
 	} else {