From: Dan Williams Subject: Re: [PATCH 3/6] async_tx: Handle DMA devices having support for fewer PQ coefficients Date: Wed, 1 Feb 2017 22:01:13 -0800 Message-ID: References: <1486010836-25228-1-git-send-email-anup.patel@broadcom.com> <1486010836-25228-4-git-send-email-anup.patel@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Vinod Koul , Rob Herring , Mark Rutland , Herbert Xu , "David S . Miller" , Jassi Brar , Ray Jui , Scott Branden , Jon Mason , Rob Rice , bcm-kernel-feedback-list@broadcom.com, "dmaengine@vger.kernel.org" , devicetree@vger.kernel.org, "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org, linux-raid To: Anup Patel Return-path: Received: from mail-ot0-f169.google.com ([74.125.82.169]:34572 "EHLO mail-ot0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbdBBGBO (ORCPT ); Thu, 2 Feb 2017 01:01:14 -0500 Received: by mail-ot0-f169.google.com with SMTP id f9so4745898otd.1 for ; Wed, 01 Feb 2017 22:01:14 -0800 (PST) In-Reply-To: <1486010836-25228-4-git-send-email-anup.patel@broadcom.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Wed, Feb 1, 2017 at 8:47 PM, Anup Patel wrote: > The DMAENGINE framework assumes that if PQ offload is supported by a > DMA device then all 256 PQ coefficients are supported. This assumption > does not hold anymore because we now have BCM-SBA-RAID offload engine > which supports PQ offload with limited number of PQ coefficients. > > This patch extends async_tx APIs to handle DMA devices with support > for fewer PQ coefficients. > > Signed-off-by: Anup Patel > Reviewed-by: Scott Branden > --- > crypto/async_tx/async_pq.c | 3 +++ > crypto/async_tx/async_raid6_recov.c | 12 ++++++++++-- > include/linux/dmaengine.h | 19 +++++++++++++++++++ > include/linux/raid/pq.h | 3 +++ > 4 files changed, 35 insertions(+), 2 deletions(-) So, I hate the way async_tx does these checks on each operation, and it's ok for me to say that because it's my fault. Really it's md that should be validating engine offload capabilities once at the beginning of time. I'd rather we move in that direction than continue to pile onto a bad design.