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 <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>

arch/powerpc/include/asm/opal.h

···
 
 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 */

arch/powerpc/platforms/powernv/opal-sensor.c

···
 			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;
 

arch/powerpc/platforms/powernv/opal-sysparam.c

···
 		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);
···
 		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);

drivers/i2c/busses/i2c-opal.c

···
 	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;

drivers/leds/leds-powernv.c

···
 		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);

drivers/mtd/devices/powernv_flash.c

···
 		return -EIO;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc == OPAL_SUCCESS) {
 		rc = 0;
 		if (retlen)

drivers/rtc/rtc-opal.c

···
 		goto exit;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS) {
 		rc = -EIO;
 		goto exit;
···
 		goto exit;
 	}
 
-	rc = be64_to_cpu(msg.params[1]);
+	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS)
 		rc = -EIO;