From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v2 1/8] crypto: support (de)compression API that doesn't
 require tfm object
Date: Thu, 20 Aug 2015 17:05:48 +0900
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Cc: Andrew Morton <akpm@linux-foundation.org>,
	Minchan Kim <minchan@kernel.org>,
	Nitin Gupta <ngupta@vflare.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Stephan Mueller <smueller@chronox.de>
To: Herbert Xu <herbert@gondor.apana.org.au>
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On Thu, Aug 20, 2015 at 03:50:35PM +0800, Herbert Xu wrote:
> On Thu, Aug 20, 2015 at 04:52:17PM +0900, Joonsoo Kim wrote:
> > 
> > Hmm... I guess there is no problem. crypto_alg object fetched by
> > crypto_get_comp() introduced in this patch could be hardware device
> > algorithm which is same one that we can eventually fetch from tfm object.
> > So, this approach would correctly track the crypto_alg regardless
> > it is a hardware one or not. If there is some dependency between
> > algorithm and tfm, it can't support _noctx API. Am I missing
> > something?
> 
> Your approach limits what hardware devices we can support in
> future.  It is fairly common for hardware drivers to only allocate
> resources when a tfm is created.  With your tfmless interface,
> the driver would have to unconditionally allocate resources.

Ah...Okay. thanks for clarifying.

> 
> It is essentially a global tfm without the tfm.
> 
> > Yes, I thought this way before, but, current way is much simpler so
> > I try it first. If it is not acceptable, I will implement this
> > approach.
> 
> Please go with a global tfm.

Okay. Will do that in next spin.

Thanks.