From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients Date: Tue, 7 Feb 2017 22:12:08 +0530 Message-ID: <20170207164207.GI19244@localhost> 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=us-ascii Cc: Dan Williams , 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: Anup Patel Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Tue, Feb 07, 2017 at 02:32:15PM +0530, 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. If the question is only for advertising caps, then why not do as done for dma_get_slave_caps(). you can add dma_get_pq_caps() so that clients (md) in this case would know the HW capability. > 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. > > Regards, > Anup -- ~Vinod From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755200AbdBGQlo (ORCPT ); Tue, 7 Feb 2017 11:41:44 -0500 Received: from mga02.intel.com ([134.134.136.20]:58088 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752160AbdBGQlm (ORCPT ); Tue, 7 Feb 2017 11:41:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,346,1477983600"; d="scan'208";a="931157246" Date: Tue, 7 Feb 2017 22:12:08 +0530 From: Vinod Koul To: Anup Patel Cc: Dan Williams , 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 Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients Message-ID: <20170207164207.GI19244@localhost> 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=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 07, 2017 at 02:32:15PM +0530, 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. If the question is only for advertising caps, then why not do as done for dma_get_slave_caps(). you can add dma_get_pq_caps() so that clients (md) in this case would know the HW capability. > 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. > > Regards, > Anup -- ~Vinod From mboxrd@z Thu Jan 1 00:00:00 1970 From: vinod.koul@intel.com (Vinod Koul) Date: Tue, 7 Feb 2017 22:12:08 +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: <20170207164207.GI19244@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Feb 07, 2017 at 02:32:15PM +0530, 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. If the question is only for advertising caps, then why not do as done for dma_get_slave_caps(). you can add dma_get_pq_caps() so that clients (md) in this case would know the HW capability. > 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. > > Regards, > Anup -- ~Vinod