From: Dan Streetman Subject: Re: [PATCH 09/11] crypto: remove LZO fallback from crypto 842 Date: Wed, 8 Apr 2015 10:28:23 -0400 Message-ID: References: <1428428070-17803-1-git-send-email-ddstreet@ieee.org> <1428428070-17803-10-git-send-email-ddstreet@ieee.org> <20150408141600.GA30338@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: "David S. Miller" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Seth Jennings , Robert Jennings , linux-crypto@vger.kernel.org, "linuxppc-dev@lists.ozlabs.org" , linux-kernel To: Herbert Xu Return-path: In-Reply-To: <20150408141600.GA30338@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Wed, Apr 8, 2015 at 10:16 AM, Herbert Xu wrote: > On Tue, Apr 07, 2015 at 01:34:28PM -0400, Dan Streetman wrote: >> Update the crypto 842 driver to no longer fallback to LZO if the 842 >> hardware is unavailable. Simplify the crpypto 842 driver to remove all >> headers indicating 842/lzo. >> >> The crypto 842 driver should do 842-format compression and decompression >> only. It should not fallback to LZO compression/decompression. The >> user of the crypto 842 driver can fallback to another format if desired. >> >> Signed-off-by: Dan Streetman > > Thanks for the series. I don't know how I missed it when it was > merged originally but crypto/842.c needs to be moved over to > drivers/crypto. Your software implementation should take its > places as the reference implementation. So, the sw implementation is only for decompression; there's no sw compression implementation in these patches. The hw 842 driver is currently at drivers/crypto/nx, and the crypto/842 driver just calls the hw driver (after correctly aligning/sizing the provided buffers to what the hw driver expects), and falls back to the sw decompression if the hw decompression fails (there is no compression fallback, a failure is reported to the caller). Is that setup ok? If users had to directly call the hw driver, instead of using the generic crypto_comp interface, it would complicate things, e.g. in zswap it only expects to call crypto_comp_compress()/decompress(), not call the 842 hw driver directly. > > Cheers, > -- > Email: Herbert Xu > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt