[PATCH] ppc64: error code cleanups for rtas wrappers

This patch is from John Rose <johnrose@austin.ibm.com>

This patch changes the rtas wrapper functions in rtas.c to map RTAS
failure codes to conventional error values.  The goal is to make
failure conditions obvious in the wrapper functions and in the caller
code.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/kernel/pSeries_smp.c

@@ -151,7 +151,7 @@ static unsigned int find_physical_cpu_to_start(unsigned int old_hwindex)
 		if (index) {
 			int state;
 			int rc = rtas_get_sensor(9003, *index, &state);
-			if (rc != 0 || state != 1)
+			if (rc < 0 || state != 1)
 				continue;
 		}
 

arch/ppc64/kernel/rtas.c

@@ -255,29 +255,59 @@ rtas_extended_busy_delay_time(int status)
 	return ms; 
 }
 
-int
-rtas_get_power_level(int powerdomain, int *level)
+int rtas_error_rc(int rtas_rc)
+{
+	int rc;
+
+	switch (rtas_rc) {
+		case -1: 		/* Hardware Error */
+			rc = -EIO;
+			break;
+		case -3:		/* Bad indicator/domain/etc */
+			rc = -EINVAL;
+			break;
+		case -9000:		/* Isolation error */
+			rc = -EFAULT;
+			break;
+		case -9001:		/* Outstanding TCE/PTE */
+			rc = -EEXIST;
+			break;
+		case -9002:		/* No usable slot */
+			rc = -ENODEV;
+			break;
+		default:
+			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
+					__FUNCTION__, rtas_rc);
+			rc = -ERANGE;
+			break;
+	}
+	return rc;
+}
+
+int rtas_get_power_level(int powerdomain, int *level)
 {
 	int token = rtas_token("get-power-level");
 	int rc;
 
 	if (token == RTAS_UNKNOWN_SERVICE)
-		return RTAS_UNKNOWN_OP;
+		return -ENOENT;
 
 	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
 		udelay(1);
+
+	if (rc < 0)
+		return rtas_error_rc(rc);
 	return rc;
 }
 
-int
-rtas_set_power_level(int powerdomain, int level, int *setlevel)
+int rtas_set_power_level(int powerdomain, int level, int *setlevel)
 {
 	int token = rtas_token("set-power-level");
 	unsigned int wait_time;
 	int rc;
 
 	if (token == RTAS_UNKNOWN_SERVICE)
-		return RTAS_UNKNOWN_OP;
+		return -ENOENT;
 
 	while (1) {
 		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
@@ -289,18 +319,20 @@ rtas_set_power_level(int powerdomain, int level, int *setlevel)
 		} else
 			break;
 	}
+
+	if (rc < 0)
+		return rtas_error_rc(rc);
 	return rc;
 }
 
-int
-rtas_get_sensor(int sensor, int index, int *state)
+int rtas_get_sensor(int sensor, int index, int *state)
 {
 	int token = rtas_token("get-sensor-state");
 	unsigned int wait_time;
 	int rc;
 
 	if (token == RTAS_UNKNOWN_SERVICE)
-		return RTAS_UNKNOWN_OP;
+		return -ENOENT;
 
 	while (1) {
 		rc = rtas_call(token, 2, 2, state, sensor, index);
@@ -312,18 +344,20 @@ rtas_get_sensor(int sensor, int index, int *state)
 		} else
 			break;
 	}
+
+	if (rc < 0)
+		return rtas_error_rc(rc);
 	return rc;
 }
 
-int
-rtas_set_indicator(int indicator, int index, int new_value)
+int rtas_set_indicator(int indicator, int index, int new_value)
 {
 	int token = rtas_token("set-indicator");
 	unsigned int wait_time;
 	int rc;
 
 	if (token == RTAS_UNKNOWN_SERVICE)
-		return RTAS_UNKNOWN_OP;
+		return -ENOENT;
 
 	while (1) {
 		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
@@ -337,6 +371,8 @@ rtas_set_indicator(int indicator, int index, int new_value)
 			break;
 	}
 
+	if (rc < 0)
+		return rtas_error_rc(rc);
 	return rc;
 }
 

arch/ppc64/kernel/rtasd.c

@@ -347,7 +347,7 @@ static int enable_surveillance(int timeout)
 	if (error == 0)
 		return 0;
 
-	if (error == RTAS_NO_SUCH_INDICATOR) {
+	if (error == -EINVAL) {
 		printk(KERN_INFO "rtasd: surveillance not supported\n");
 		return 0;
 	}

arch/ppc64/kernel/xics.c

@@ -654,7 +654,7 @@ void xics_migrate_irqs_away(void)
 	/* remove ourselves from the global interrupt queue */
 	status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 		(1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
-	WARN_ON(status != 0);
+	WARN_ON(status < 0);
 
 	/* Allow IPIs again... */
 	ops->cppr_info(cpu, DEFAULT_PRIORITY);

include/asm-ppc64/rtas.h

@@ -24,12 +24,9 @@
 
 /* RTAS return status codes */
 #define RTAS_BUSY		-2    /* RTAS Busy */
-#define RTAS_NO_SUCH_INDICATOR	-3    /* No such indicator implemented */
 #define RTAS_EXTENDED_DELAY_MIN	9900
 #define RTAS_EXTENDED_DELAY_MAX	9905
 
-#define RTAS_UNKNOWN_OP		-1099 /* Unknown RTAS Token */
-
 /*
  * In general to call RTAS use rtas_token("string") to lookup
  * an RTAS token for the given string (e.g. "event-scan").