From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032181AbdD0PqX (ORCPT ); Thu, 27 Apr 2017 11:46:23 -0400 Received: from ale.deltatee.com ([207.54.116.67]:56991 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030419AbdD0PqO (ORCPT ); Thu, 27 Apr 2017 11:46:14 -0400 To: Herbert Xu References: <1493144468-22493-1-git-send-email-logang@deltatee.com> <1493144468-22493-8-git-send-email-logang@deltatee.com> <20170427035603.GA32212@gondor.apana.org.au> Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-nvdimm@ml01.01.org, linux-scsi@vger.kernel.org, open-iscsi@googlegroups.com, megaraidlinux.pdl@broadcom.com, sparmaintainer@unisys.com, devel@driverdev.osuosl.org, target-devel@vger.kernel.org, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, dm-devel@redhat.com, Christoph Hellwig , "Martin K. Petersen" , "James E.J. Bottomley" , Jens Axboe , Greg Kroah-Hartman , Dan Williams , Ross Zwisler , Matthew Wilcox , Sumit Semwal , Stephen Bates , "David S. Miller" From: Logan Gunthorpe Message-ID: <94123cbf-3287-f05e-7267-0bcf08ab0a8b@deltatee.com> Date: Thu, 27 Apr 2017 09:45:57 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170427035603.GA32212@gondor.apana.org.au> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.111 X-SA-Exim-Rcpt-To: davem@davemloft.net, sbates@raithlin.com, sumit.semwal@linaro.org, mawilcox@microsoft.com, ross.zwisler@linux.intel.com, dan.j.williams@intel.com, gregkh@linuxfoundation.org, axboe@kernel.dk, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, hch@lst.de, dm-devel@redhat.com, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, target-devel@vger.kernel.org, devel@driverdev.osuosl.org, sparmaintainer@unisys.com, megaraidlinux.pdl@broadcom.com, open-iscsi@googlegroups.com, linux-scsi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mmc@vger.kernel.org, linux-raid@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, herbert@gondor.apana.org.au X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v2 07/21] crypto: shash, caam: Make use of the new sg_map helper function X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/04/17 09:56 PM, Herbert Xu wrote: > On Tue, Apr 25, 2017 at 12:20:54PM -0600, Logan Gunthorpe wrote: >> Very straightforward conversion to the new function in the caam driver >> and shash library. >> >> Signed-off-by: Logan Gunthorpe >> Cc: Herbert Xu >> Cc: "David S. Miller" >> --- >> crypto/shash.c | 9 ++++++--- >> drivers/crypto/caam/caamalg.c | 8 +++----- >> 2 files changed, 9 insertions(+), 8 deletions(-) >> >> diff --git a/crypto/shash.c b/crypto/shash.c >> index 5e31c8d..5914881 100644 >> --- a/crypto/shash.c >> +++ b/crypto/shash.c >> @@ -283,10 +283,13 @@ int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc) >> if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) { >> void *data; >> >> - data = kmap_atomic(sg_page(sg)); >> - err = crypto_shash_digest(desc, data + offset, nbytes, >> + data = sg_map(sg, 0, SG_KMAP_ATOMIC); >> + if (IS_ERR(data)) >> + return PTR_ERR(data); >> + >> + err = crypto_shash_digest(desc, data, nbytes, >> req->result); >> - kunmap_atomic(data); >> + sg_unmap(sg, data, 0, SG_KMAP_ATOMIC); >> crypto_yield(desc->flags); >> } else >> err = crypto_shash_init(desc) ?: > > Nack. This is an optimisation for the special case of a single > SG list entry. In fact in the common case the kmap_atomic should > disappear altogether in the no-highmem case. So replacing it > with sg_map is not acceptable. What you seem to have missed is that sg_map is just a thin wrapper around kmap_atomic. Perhaps with a future check for a mappable page. This change should have zero impact on performance. Logan