Subject: Re: [v2,1/3] powerpc/powernv: convert codes returned by OPAL calls

From: Cedric Le Goater <[email-masked]>
Date: Fri, 27 Mar 2015 11:45:00 +0100

On 03/27/2015 10:59 AM, Michael Ellerman wrote:
> On Thu, 2015-26-03 at 16:04:45 UTC, =?utf-8?q?C=C3=A9dric_Le_Goater?= wrote:
>> OPAL has its own list of return codes. The patch provides a translation
>> of such codes in errnos for the opal_sensor_read call.
>>
>> Signed-off-by: Cédric Le Goater <[email-masked]>
>> ---
>>  arch/powerpc/platforms/powernv/opal-sensor.c |   37 ++++++++++++++++++++++++++-
>>  1 file changed, 36 insertions(+), 1 deletion(-)
>>
>> Index: linux.git/arch/powerpc/platforms/powernv/opal-sensor.c
>> ===================================================================
>> --- linux.git.orig/arch/powerpc/platforms/powernv/opal-sensor.c
>> +++ linux.git/arch/powerpc/platforms/powernv/opal-sensor.c
>> @@ -26,6 +26,38 @@
>   
>> +static int convert_opal_code(int ret)
>> +{
>> +	switch (ret) {
>> +	case OPAL_SUCCESS:		return 0;
>> +	case OPAL_PARAMETER:		return -EINVAL;
>> +	case OPAL_UNSUPPORTED:		return -ENOSYS;
>> +	case OPAL_ASYNC_COMPLETION:	return -EAGAIN;
>> +	case OPAL_BUSY_EVENT:		return -EBUSY;
>> +	case OPAL_NO_MEM:		return -ENOMEM;
>> +	case OPAL_HARDWARE:		return -ENOENT;
>> +	case OPAL_INTERNAL_ERROR:	return -EIO;
>> +	default:			return -EIO;
>> +	}
>> +}
> 
> That looks a bit familiar :)

Ah ! I only looked in opal ...

> static 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",
> 					__func__, rtas_rc);
> 			rc = -ERANGE;

this a better code default value.

> 			break;
> 	}
> 	return rc;
> }
> 
> 
> But I guess we still should have it.
> 
> Can you put it in opal.h and give it a better name, maybe opal_error_code() ?

Sure. I will change the name but opal.c looks better, knowing that opal.h is 
shared with skiboot.

> 
>>  /*
>>   * This will return sensor information to driver based on the requested sensor
>>   * handle. A handle is an opaque id for the powernv, read by the driver from the
>> @@ -46,8 +78,10 @@ int opal_get_sensor_data(u32 sensor_hndl
>>  
>>  	mutex_lock(&opal_sensor_mutex);
>>  	ret = opal_sensor_read(sensor_hndl, token, &data);
>> -	if (ret != OPAL_ASYNC_COMPLETION)
>> +	if (ret != OPAL_ASYNC_COMPLETION) {
>> +		ret = convert_opal_code(ret);
>>  		goto out_token;
>> +	}
>>  
>>  	ret = opal_async_wait_response(token, &msg);
>>  	if (ret) {
>> @@ -58,6 +92,7 @@ int opal_get_sensor_data(u32 sensor_hndl
>>  
>>  	*sensor_data = be32_to_cpu(data);
>>  	ret = be64_to_cpu(msg.params[1]);
>> +	ret = convert_opal_code(ret);
> 
> I'd do:
> 	ret = convert_opal_code(be64_to_cpu(msg.params[1]));

Yes. the double 'ret =' is ugly.

Thanks,

C.