powerpc/powernv: convert codes returned by OPAL calls

OPAL has its own list of return codes. The patch provides a translation
of such codes in errnos for the opal_sensor_read call, and possibly
others if needed.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/opal.h

@@ -247,6 +247,8 @@ struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
 					     unsigned long vmalloc_size);
 void opal_free_sg_list(struct opal_sg_list *sg);
 
+extern int opal_error_code(int rc);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_OPAL_H */

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

@@ -46,8 +46,10 @@ int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
 
 	mutex_lock(&opal_sensor_mutex);
 	ret = opal_sensor_read(sensor_hndl, token, &data);
-	if (ret != OPAL_ASYNC_COMPLETION)
+	if (ret != OPAL_ASYNC_COMPLETION) {
+		ret = opal_error_code(ret);
 		goto out_token;
+	}
 
 	ret = opal_async_wait_response(token, &msg);
 	if (ret) {
@@ -57,7 +59,7 @@ int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
 	}
 
 	*sensor_data = be32_to_cpu(data);
-	ret = be64_to_cpu(msg.params[1]);
+	ret = opal_error_code(be64_to_cpu(msg.params[1]));
 
 out_token:
 	mutex_unlock(&opal_sensor_mutex);

arch/powerpc/platforms/powernv/opal.c

@@ -931,6 +931,25 @@ void opal_free_sg_list(struct opal_sg_list *sg)
 	}
 }
 
+int opal_error_code(int rc)
+{
+	switch (rc) {
+	case OPAL_SUCCESS:		return 0;
+
+	case OPAL_PARAMETER:		return -EINVAL;
+	case OPAL_ASYNC_COMPLETION:	return -EINPROGRESS;
+	case OPAL_BUSY_EVENT:		return -EBUSY;
+	case OPAL_NO_MEM:		return -ENOMEM;
+
+	case OPAL_UNSUPPORTED:		return -EIO;
+	case OPAL_HARDWARE:		return -EIO;
+	case OPAL_INTERNAL_ERROR:	return -EIO;
+	default:
+		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
+		return -EIO;
+	}
+}
+
 EXPORT_SYMBOL_GPL(opal_poll_events);
 EXPORT_SYMBOL_GPL(opal_rtc_read);
 EXPORT_SYMBOL_GPL(opal_rtc_write);