[POWERPC] check firmware state before suspending

Currently the kernel blindly halts all the processors and calls the
ibm,suspend-me rtas call.  If the firmware is not in the correct
state, we then re-start all the processors and return.  It is much
smarter to first check the firmware state, and only if it is waiting,
call the ibm,suspend-me call.
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/rtas.c

@@ -593,9 +593,31 @@ static void rtas_percpu_suspend_me(void *info)
 static int rtas_ibm_suspend_me(struct rtas_args *args)
 {
 	int i;
+	long state;
+	long rc;
+	unsigned long dummy;
 
 	struct rtas_suspend_me_data data;
 
+	/* Make sure the state is valid */
+	rc = plpar_hcall(H_VASI_STATE,
+			 ((u64)args->args[0] << 32) | args->args[1],
+			 0, 0, 0,
+			 &state, &dummy, &dummy);
+
+	if (rc) {
+		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
+		return rc;
+	} else if (state == H_VASI_ENABLED) {
+		args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
+		return 0;
+	} else if (state != H_VASI_SUSPENDING) {
+		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
+		       state);
+		args->args[args->nargs] = -1;
+		return 0;
+	}
+
 	data.waiting = 1;
 	data.args = args;
 

include/asm-powerpc/hvcall.h

@@ -102,6 +102,15 @@
 #define H_PP1			(1UL<<(63-62))
 #define H_PP2			(1UL<<(63-63))
 
+/* VASI States */
+#define H_VASI_INVALID          0
+#define H_VASI_ENABLED          1
+#define H_VASI_ABORTED          2
+#define H_VASI_SUSPENDING       3
+#define H_VASI_SUSPENDED        4
+#define H_VASI_RESUMED          5
+#define H_VASI_COMPLETED        6
+
 /* DABRX flags */
 #define H_DABRX_HYPERVISOR	(1UL<<(63-61))
 #define H_DABRX_KERNEL		(1UL<<(63-62))
@@ -190,6 +199,7 @@
 #define H_QUERY_INT_STATE       0x1E4
 #define H_POLL_PENDING		0x1D8
 #define H_JOIN			0x298
+#define H_VASI_STATE            0x2A4
 #define H_ENABLE_CRQ		0x2B0
 
 #ifndef __ASSEMBLY__

include/asm-powerpc/rtas.h

@@ -24,6 +24,7 @@
 #define RTAS_RMOBUF_MAX (64 * 1024)
 
 /* RTAS return status codes */
+#define RTAS_NOT_SUSPENDABLE	-9004
 #define RTAS_BUSY		-2    /* RTAS Busy */
 #define RTAS_EXTENDED_DELAY_MIN	9900
 #define RTAS_EXTENDED_DELAY_MAX	9905