powerpc/opal: Add inline function to get rc from an ASYNC_COMP opal_msg

An opal_msg of type OPAL_MSG_ASYNC_COMP contains the return code in the
params[1] struct member. However this isn't intuitive or obvious when
reading the code and requires that a user look at the skiboot
documentation or opal-api.h to verify this.

Add an inline function to get the return code from an opal_msg and update
call sites accordingly.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index fa71fea..9ab52e2 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -282,6 +282,14 @@
 
 ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count);
 
+static inline int opal_get_async_rc(struct opal_msg msg)
+{
+	if (msg.msg_type != OPAL_MSG_ASYNC_COMP)
+		return OPAL_PARAMETER;
+	else
+		return be64_to_cpu(msg.params[1]);
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_OPAL_H */
diff --git a/arch/powerpc/platforms/powernv/opal-sensor.c b/arch/powerpc/platforms/powernv/opal-sensor.c
index a06059d..308efd1 100644
--- a/arch/powerpc/platforms/powernv/opal-sensor.c
+++ b/arch/powerpc/platforms/powernv/opal-sensor.c
@@ -55,7 +55,7 @@
 			goto out_token;
 		}
 
-		ret = opal_error_code(be64_to_cpu(msg.params[1]));
+		ret = opal_error_code(opal_get_async_rc(msg));
 		*sensor_data = be32_to_cpu(data);
 		break;
 
diff --git a/arch/powerpc/platforms/powernv/opal-sysparam.c b/arch/powerpc/platforms/powernv/opal-sysparam.c
index afe66c5..23fb664 100644
--- a/arch/powerpc/platforms/powernv/opal-sysparam.c
+++ b/arch/powerpc/platforms/powernv/opal-sysparam.c
@@ -67,7 +67,7 @@
 		goto out_token;
 	}
 
-	ret = opal_error_code(be64_to_cpu(msg.params[1]));
+	ret = opal_error_code(opal_get_async_rc(msg));
 
 out_token:
 	opal_async_release_token(token);
@@ -103,7 +103,7 @@
 		goto out_token;
 	}
 
-	ret = opal_error_code(be64_to_cpu(msg.params[1]));
+	ret = opal_error_code(opal_get_async_rc(msg));
 
 out_token:
 	opal_async_release_token(token);
diff --git a/drivers/i2c/busses/i2c-opal.c b/drivers/i2c/busses/i2c-opal.c
index 75dd6d04..11e2a1f 100644
--- a/drivers/i2c/busses/i2c-opal.c
+++ b/drivers/i2c/busses/i2c-opal.c
@@ -71,7 +71,7 @@
 	if (rc)
 		goto exit;
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS) {
 		rc = i2c_opal_translate_error(rc);
 		goto exit;
diff --git a/drivers/leds/leds-powernv.c b/drivers/leds/leds-powernv.c
index dfb8bd3..b2a98c7 100644
--- a/drivers/leds/leds-powernv.c
+++ b/drivers/leds/leds-powernv.c
@@ -118,7 +118,7 @@
 		goto out_token;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS)
 		dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n",
 			__func__, rc);
diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
index d5b870b..f5396f26 100644
--- a/drivers/mtd/devices/powernv_flash.c
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -95,7 +95,7 @@
 		return -EIO;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc == OPAL_SUCCESS) {
 		rc = 0;
 		if (retlen)
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index 9c18d6f..ea20f62 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -134,7 +134,7 @@
 		goto exit;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS) {
 		rc = -EIO;
 		goto exit;
@@ -181,7 +181,7 @@
 		goto exit;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS)
 		rc = -EIO;