From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7649FC433DB for ; Tue, 26 Jan 2021 21:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D92420449 for ; Tue, 26 Jan 2021 21:51:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbhAZVuZ (ORCPT ); Tue, 26 Jan 2021 16:50:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:60210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727650AbhAZRDk (ORCPT ); Tue, 26 Jan 2021 12:03:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C416022EBD; Tue, 26 Jan 2021 17:02:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611680579; bh=bUosObEPj6sBUrbn1Vw5C/9VJJ2eDmdALlTgxMH/ih0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r1Ctjdc16APYIO80/vAyDnXkJOPATRq8vAQ4XGokaXNNwlEHPGjoJjmD5Z5L5pj0A ytk+fyGbUcmuE8VQUk8L3c2h52CB/0x7Z+dHM1/KdDduuFgEUMs19WhzW0b/lSkqAr agj3UnYnx1UzPzAKEjC54N8y8UDWRWg1Dw9p7bMVymhAzidJGd4DV64pDhG7sjoTS3 p+Ql5w6ytQtgIWI0TWmQ5rATEKEzcpO4rlAeAvMmCn1RtcuvjyjgHf7hKsHmTX2PQL Q2/alOOKGNQVTbQzdFAqscmYUSxO0FZPJSeqItIBh+GPAMDJCdczAFpTP2hsYgUvm0 0ULRhvJ/sQKeA== Date: Tue, 26 Jan 2021 22:32:55 +0530 From: Vinod Koul To: Dave Jiang Cc: dmaengine@vger.kernel.org Subject: Re: [PATCH] dmaengine: idxd: add module parameter to force disable of SVA Message-ID: <20210126170255.GP2771@vkoul-mobl> References: <161074811013.2184257.13335125853932003159.stgit@djiang5-desk3.ch.intel.com> <20210117065115.GL2771@vkoul-mobl> <20210119163822.GC2771@vkoul-mobl> <425267d2-dd13-5710-65b9-d98beff2b328@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <425267d2-dd13-5710-65b9-d98beff2b328@intel.com> Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 19-01-21, 12:44, Dave Jiang wrote: > > On 1/19/2021 9:38 AM, Vinod Koul wrote: > > On 18-01-21, 10:06, Dave Jiang wrote: > > > On 1/16/2021 11:51 PM, Vinod Koul wrote: > > > > On 15-01-21, 15:01, Dave Jiang wrote: > > > > > Add a module parameter that overrides the SVA feature enabling. This keeps > > > > > the driver in legacy mode even when intel_iommu=sm_on is set. In this mode, > > > > > the descriptor fields must be programmed with dma_addr_t from the Linux DMA > > > > > API for source, destination, and completion descriptors. > > > > > > > > > > Signed-off-by: Dave Jiang > > > > > --- > > > > > drivers/dma/idxd/init.c | 8 +++++++- > > > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > > > > > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c > > > > > index 25cc947c6179..9687a24ff982 100644 > > > > > --- a/drivers/dma/idxd/init.c > > > > > +++ b/drivers/dma/idxd/init.c > > > > > @@ -26,6 +26,10 @@ MODULE_VERSION(IDXD_DRIVER_VERSION); > > > > > MODULE_LICENSE("GPL v2"); > > > > > MODULE_AUTHOR("Intel Corporation"); > > > > > +static bool sva = true; > > > > > +module_param(sva, bool, 0644); > > > > > +MODULE_PARM_DESC(sva, "Toggle SVA support on/off"); > > > > Documentation for this please.. > > > Just comments or is there somewhere specific for driver module parameter > > > documentations? > > All the parameters are supposed to be documented in Documentation/admin-guide/kernel-parameters.txt > > It seems to be for core kernel components and subsystems, and not specific > device drivers. I'm not seeing any of the dmaengine driver module params > being in this doc after grepping in drivers/dma. Yeah we should fix that as well :) -- ~Vinod