Async Crypto API

Async Crypto API

[Dmitry Kasatkin]

Hello,

I have one question about async api.

I work on AHASH driver and wonder about one thing.

while calculating hash, client might call many times

ahash_request_set_crypt(req, &sg, sha1, len);
crypto_ahash_update(req);
..
..
ahash_request_set_crypt(req, &sg, sha1, len);
crypto_ahash_finup(req);

right?

But because it is async and driver does not wait_for_completion,
 previous request may not be completed before client will call next update.

But what should be the behavior of the driver?

Thanks,
Dmitry

Re: Async Crypto API

[Herbert Xu]

Dmitry Kasatkin <dmitry.kasatkin@nokia.com> wrote:
> Hello,
> 
> I have one question about async api.
> 
> I work on AHASH driver and wonder about one thing.
> 
> while calculating hash, client might call many times
> 
> ahash_request_set_crypt(req, &sg, sha1, len);
> crypto_ahash_update(req);
> ..
> ..
> ahash_request_set_crypt(req, &sg, sha1, len);
> crypto_ahash_finup(req);
> 
> right?
> 
> But because it is async and driver does not wait_for_completion,
> previous request may not be completed before client will call next update.
> 
> But what should be the behavior of the driver?

If any async operation returns EINPROGRESS, the client must not
proceed until that operation has completed.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: Async Crypto API

[Dmitry Kasatkin]

Hi,

1 more question.

>From what context "crypto_completion_t" can be called?
irq/tasklet/process
or something else?


Thanks,
Dmitry



ext Herbert Xu wrote:
> Dmitry Kasatkin <dmitry.kasatkin@nokia.com> wrote:
>   
>> Hello,
>>
>> I have one question about async api.
>>
>> I work on AHASH driver and wonder about one thing.
>>
>> while calculating hash, client might call many times
>>
>> ahash_request_set_crypt(req, &sg, sha1, len);
>> crypto_ahash_update(req);
>> ..
>> ..
>> ahash_request_set_crypt(req, &sg, sha1, len);
>> crypto_ahash_finup(req);
>>
>> right?
>>
>> But because it is async and driver does not wait_for_completion,
>> previous request may not be completed before client will call next update.
>>
>> But what should be the behavior of the driver?
>>     
>
> If any async operation returns EINPROGRESS, the client must not
> proceed until that operation has completed.
>
> Cheers,
>   

Re: Async Crypto API

[Herbert Xu]

On Wed, Jan 27, 2010 at 08:45:12AM +0200, Dmitry Kasatkin wrote:
> Hi,
> 
> 1 more question.
> 
> >From what context "crypto_completion_t" can be called?
> irq/tasklet/process
> or something else?

tasklet or process with BH off.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: Async Crypto API

[Dmitry Kasatkin]

Hi,

In the case when finup() is not used, just update/update/../final
driver finalize calculation from the final function.

It takes a time and if it may not sleep, can final() also return
EINPROGRESS?

Thanks,
Dmitry


ext Herbert Xu wrote:
> Dmitry Kasatkin <dmitry.kasatkin@nokia.com> wrote:
>   
>> Hello,
>>
>> I have one question about async api.
>>
>> I work on AHASH driver and wonder about one thing.
>>
>> while calculating hash, client might call many times
>>
>> ahash_request_set_crypt(req, &sg, sha1, len);
>> crypto_ahash_update(req);
>> ..
>> ..
>> ahash_request_set_crypt(req, &sg, sha1, len);
>> crypto_ahash_finup(req);
>>
>> right?
>>
>> But because it is async and driver does not wait_for_completion,
>> previous request may not be completed before client will call next update.
>>
>> But what should be the behavior of the driver?
>>     
>
> If any async operation returns EINPROGRESS, the client must not
> proceed until that operation has completed.
>
> Cheers,
>   

Re: Async Crypto API

[Dmitry Kasatkin]

Hi,

It actually would not make sense as final() suppose to cleanup
everything and in the case of EINPROGRESS we can not do it.

So the question how then to "wait for completion" of the hash by HW if
not to use finup()

- Dmitry


Kasatkin Dmitry (Nokia-D/Helsinki) wrote:
> Hi,
>
> In the case when finup() is not used, just update/update/../final
> driver finalize calculation from the final function.
>
> It takes a time and if it may not sleep, can final() also return
> EINPROGRESS?
>
> Thanks,
> Dmitry
>
>
> ext Herbert Xu wrote:
>   
>> Dmitry Kasatkin <dmitry.kasatkin@nokia.com> wrote:
>>   
>>     
>>> Hello,
>>>
>>> I have one question about async api.
>>>
>>> I work on AHASH driver and wonder about one thing.
>>>
>>> while calculating hash, client might call many times
>>>
>>> ahash_request_set_crypt(req, &sg, sha1, len);
>>> crypto_ahash_update(req);
>>> ..
>>> ..
>>> ahash_request_set_crypt(req, &sg, sha1, len);
>>> crypto_ahash_finup(req);
>>>
>>> right?
>>>
>>> But because it is async and driver does not wait_for_completion,
>>> previous request may not be completed before client will call next update.
>>>
>>> But what should be the behavior of the driver?
>>>     
>>>       
>> If any async operation returns EINPROGRESS, the client must not
>> proceed until that operation has completed.
>>
>> Cheers,
>>   
>>     
> --
> To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>   

Re: Async Crypto API

[Dmitry Kasatkin]

in sync API final() does not have any data.

Is async driver also should ignore req->src in final() call?

- Dmitry


Kasatkin Dmitry (Nokia-D/Helsinki) wrote:
> Hi,
>
> It actually would not make sense as final() suppose to cleanup
> everything and in the case of EINPROGRESS we can not do it.
>
> So the question how then to "wait for completion" of the hash by HW if
> not to use finup()
>
> - Dmitry
>
>
> Kasatkin Dmitry (Nokia-D/Helsinki) wrote:
>   
>> Hi,
>>
>> In the case when finup() is not used, just update/update/../final
>> driver finalize calculation from the final function.
>>
>> It takes a time and if it may not sleep, can final() also return
>> EINPROGRESS?
>>
>> Thanks,
>> Dmitry
>>
>>
>> ext Herbert Xu wrote:
>>   
>>     
>>> Dmitry Kasatkin <dmitry.kasatkin@nokia.com> wrote:
>>>   
>>>     
>>>       
>>>> Hello,
>>>>
>>>> I have one question about async api.
>>>>
>>>> I work on AHASH driver and wonder about one thing.
>>>>
>>>> while calculating hash, client might call many times
>>>>
>>>> ahash_request_set_crypt(req, &sg, sha1, len);
>>>> crypto_ahash_update(req);
>>>> ..
>>>> ..
>>>> ahash_request_set_crypt(req, &sg, sha1, len);
>>>> crypto_ahash_finup(req);
>>>>
>>>> right?
>>>>
>>>> But because it is async and driver does not wait_for_completion,
>>>> previous request may not be completed before client will call next update.
>>>>
>>>> But what should be the behavior of the driver?
>>>>     
>>>>       
>>>>         
>>> If any async operation returns EINPROGRESS, the client must not
>>> proceed until that operation has completed.
>>>
>>> Cheers,
>>>   
>>>     
>>>       
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>   
>>     
> --
> To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>   

Re: Async Crypto API

[Herbert Xu]

On Tue, Feb 02, 2010 at 03:46:58PM +0200, Dmitry Kasatkin wrote:
> in sync API final() does not have any data.
> 
> Is async driver also should ignore req->src in final() call?

Yes req->src can be ignored in final.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: Async Crypto API

[Herbert Xu]

On Tue, Feb 02, 2010 at 02:17:51PM +0200, Dmitry Kasatkin wrote:
> Hi,
> 
> In the case when finup() is not used, just update/update/../final
> driver finalize calculation from the final function.
> 
> It takes a time and if it may not sleep, can final() also return
> EINPROGRESS?

Sure, final can certainly return EINPROGRESS.
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt