Re: [PATCH 1/7] crypto: qce: common: Add MAC failed error checking

[Thara Gopinath]

Hi Bjorn,

Thanks for the reviews.
I realized that I had these replies in my draft for a while and forgot 
to send them!

On 4/5/21 1:36 PM, Bjorn Andersson wrote:
> On Thu 25 Feb 12:27 CST 2021, Thara Gopinath wrote:
>
> > MAC_FAILED gets set in the status register if authenthication fails
> > for ccm algorithms(during decryption). Add support to catch and flag
> > this error.
> >
> > Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
> > ---
> >   drivers/crypto/qce/common.c | 11 ++++++++---
> >   1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/crypto/qce/common.c b/drivers/crypto/qce/common.c
> > index dceb9579d87a..7c3cb483749e 100644
> > --- a/drivers/crypto/qce/common.c
> > +++ b/drivers/crypto/qce/common.c
> > @@ -403,7 +403,8 @@ int qce_start(struct crypto_async_request *async_req, u32 type)
> >   }
> >   
> >   #define STATUS_ERRORS	\
> > -		(BIT(SW_ERR_SHIFT) | BIT(AXI_ERR_SHIFT) | BIT(HSD_ERR_SHIFT))
> > +		(BIT(SW_ERR_SHIFT) | BIT(AXI_ERR_SHIFT) |	\
> > +		 BIT(HSD_ERR_SHIFT) | BIT(MAC_FAILED_SHIFT))
> >   
> >   int qce_check_status(struct qce_device *qce, u32 *status)
> >   {
> > @@ -417,8 +418,12 @@ int qce_check_status(struct qce_device *qce, u32 *status)
> >   	 * use result_status from result dump the result_status needs to be byte
> >   	 * swapped, since we set the device to little endian.
> >   	 */
> > -	if (*status & STATUS_ERRORS || !(*status & BIT(OPERATION_DONE_SHIFT)))
> > -		ret = -ENXIO;
> > +	if (*status & STATUS_ERRORS || !(*status & BIT(OPERATION_DONE_SHIFT))) {
> > +		if (*status & BIT(MAC_FAILED_SHIFT))
>
> Afaict MAC_FAILED indicates a different category of errors from the
> others. So I would prefer that the conditionals are flattened.
>
> Is OPERATION_DONE set when MAC_FAILED?
Yes it is. I will change the check to the pattern you have suggested. It 
is less confusing..

> If so:
>
> if (errors || !done)
> 	return -ENXIO;
> else if (*status & BIT(MAC_FAILED))
> 	return -EBADMSG;
>
> Would be cleaner in my opinion.
>
> Regards,
> Bjorn
>
> > +			ret = -EBADMSG;
> > +		else
> > +			ret = -ENXIO;
> > +	}
> >   
> >   	return ret;
> >   }
> > --
> > 2.25.1

--
Warm Regards
Thara