From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anup Patel Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients Date: Wed, 8 Feb 2017 14:27:23 +0530 Message-ID: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-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 , "dmaengine@vger.kernel.org" , Device Tree , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org, linux-raid To: Dan Williams Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Tue, Feb 7, 2017 at 11:46 PM, Dan Williams wrote: > On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: >> On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >>> On Tue, Feb 7, 2017 at 12:16 AM, 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 >>> >>> I don't like this approach. Define an interface for md to query the >>> offload engine once at the beginning of time. We should not be adding >>> any new extensions to async_tx. >> >> Even if we do capability checks in Linux MD, we still need a way >> for DMAENGINE drivers to advertise number of PQ coefficients >> handled by the HW. >> >> I agree capability checks should be done once in Linux MD but I don't >> see why this has to be part of BCM-SBA-RAID driver patches. We need >> separate patchsets to address limitations of async_tx framework. > > Right, separate enabling before we pile on new hardware support to a > known broken framework. Linux Async Tx not broken framework. The issue is: 1. Its not complete enough 2. Its not optimized for very high through-put offload engines Regards, Anup From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933039AbdBHI63 (ORCPT ); Wed, 8 Feb 2017 03:58:29 -0500 Received: from mail-ua0-f181.google.com ([209.85.217.181]:34960 "EHLO mail-ua0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932954AbdBHI5Z (ORCPT ); Wed, 8 Feb 2017 03:57:25 -0500 MIME-Version: 1.0 In-Reply-To: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-git-send-email-anup.patel@broadcom.com> From: Anup Patel Date: Wed, 8 Feb 2017 14:27:23 +0530 Message-ID: Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients To: Dan Williams 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 , "dmaengine@vger.kernel.org" , Device Tree , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org, linux-raid Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 7, 2017 at 11:46 PM, Dan Williams wrote: > On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: >> On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >>> On Tue, Feb 7, 2017 at 12:16 AM, 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 >>> >>> I don't like this approach. Define an interface for md to query the >>> offload engine once at the beginning of time. We should not be adding >>> any new extensions to async_tx. >> >> Even if we do capability checks in Linux MD, we still need a way >> for DMAENGINE drivers to advertise number of PQ coefficients >> handled by the HW. >> >> I agree capability checks should be done once in Linux MD but I don't >> see why this has to be part of BCM-SBA-RAID driver patches. We need >> separate patchsets to address limitations of async_tx framework. > > Right, separate enabling before we pile on new hardware support to a > known broken framework. Linux Async Tx not broken framework. The issue is: 1. Its not complete enough 2. Its not optimized for very high through-put offload engines Regards, Anup From mboxrd@z Thu Jan 1 00:00:00 1970 From: anup.patel@broadcom.com (Anup Patel) Date: Wed, 8 Feb 2017 14:27:23 +0530 Subject: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients In-Reply-To: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-git-send-email-anup.patel@broadcom.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Feb 7, 2017 at 11:46 PM, Dan Williams wrote: > On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: >> On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >>> On Tue, Feb 7, 2017 at 12:16 AM, 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 >>> >>> I don't like this approach. Define an interface for md to query the >>> offload engine once at the beginning of time. We should not be adding >>> any new extensions to async_tx. >> >> Even if we do capability checks in Linux MD, we still need a way >> for DMAENGINE drivers to advertise number of PQ coefficients >> handled by the HW. >> >> I agree capability checks should be done once in Linux MD but I don't >> see why this has to be part of BCM-SBA-RAID driver patches. We need >> separate patchsets to address limitations of async_tx framework. > > Right, separate enabling before we pile on new hardware support to a > known broken framework. Linux Async Tx not broken framework. The issue is: 1. Its not complete enough 2. Its not optimized for very high through-put offload engines Regards, Anup