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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, TVD_SUBJ_WIPE_DEBT,URIBL_BLOCKED,USER_AGENT_SANE_2 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 2EE17C2BB1D for ; Thu, 9 Apr 2020 08:55:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EF45E20757 for ; Thu, 9 Apr 2020 08:55:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF45E20757 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AA4D48E000D; Thu, 9 Apr 2020 04:55:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A2E798E0006; Thu, 9 Apr 2020 04:55:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 91DFB8E000D; Thu, 9 Apr 2020 04:55:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0185.hostedemail.com [216.40.44.185]) by kanga.kvack.org (Postfix) with ESMTP id 81C3C8E0006 for ; Thu, 9 Apr 2020 04:55:25 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4CC10181AEF3F for ; Thu, 9 Apr 2020 08:55:25 +0000 (UTC) X-FDA: 76687707810.28.sense12_4c606f5d9cc3e X-HE-Tag: sense12_4c606f5d9cc3e X-Filterd-Recvd-Size: 4291 Received: from kernel.crashing.org (kernel.crashing.org [76.164.61.194]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Apr 2020 08:55:24 +0000 (UTC) Received: from localhost (gate.crashing.org [63.228.1.57]) (authenticated bits=0) by kernel.crashing.org (8.14.7/8.14.7) with ESMTP id 0398s3us004063 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 9 Apr 2020 03:54:07 -0500 Message-ID: Subject: Re: [PATCH 19/28] gpu/drm: remove the powerpc hack in drm_legacy_sg_alloc From: Benjamin Herrenschmidt To: Daniel Vetter , Christoph Hellwig Cc: Andrew Morton , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , x86@kernel.org, David Airlie , Laura Abbott , Sumit Semwal , Sakari Ailus , Minchan Kim , Nitin Gupta , Robin Murphy , Christophe Leroy , Peter Zijlstra , linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 09 Apr 2020 18:54:01 +1000 In-Reply-To: <20200408122504.GO3456981@phenom.ffwll.local> References: <20200408115926.1467567-1-hch@lst.de> <20200408115926.1467567-20-hch@lst.de> <20200408122504.GO3456981@phenom.ffwll.local> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 2020-04-08 at 14:25 +0200, Daniel Vetter wrote: > On Wed, Apr 08, 2020 at 01:59:17PM +0200, Christoph Hellwig wrote: > > If this code was broken for non-coherent caches a crude powerpc hack > > isn't going to help anyone else. Remove the hack as it is the last > > user of __vmalloc passing a page protection flag other than PAGE_KERNEL. > > Well Ben added this to make stuff work on ppc, ofc the home grown dma > layer in drm from back then isn't going to work in other places. I guess > should have at least an ack from him, in case anyone still cares about > this on ppc. Adding Ben to cc. This was due to some drivers (radeon ?) trying to use vmalloc pages for coherent DMA, which means on those 4xx powerpc's need to be non-cached. There were machines using that (440 based iirc), though I honestly can't tell if anybody still uses any of it. Cheers, Ben. > -Daniel > > > > > Signed-off-by: Christoph Hellwig > > --- > > drivers/gpu/drm/drm_scatter.c | 11 +---------- > > 1 file changed, 1 insertion(+), 10 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c > > index ca520028b2cb..f4e6184d1877 100644 > > --- a/drivers/gpu/drm/drm_scatter.c > > +++ b/drivers/gpu/drm/drm_scatter.c > > @@ -43,15 +43,6 @@ > > > > #define DEBUG_SCATTER 0 > > > > -static inline void *drm_vmalloc_dma(unsigned long size) > > -{ > > -#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) > > - return __vmalloc(size, GFP_KERNEL, pgprot_noncached_wc(PAGE_KERNEL)); > > -#else > > - return vmalloc_32(size); > > -#endif > > -} > > - > > static void drm_sg_cleanup(struct drm_sg_mem * entry) > > { > > struct page *page; > > @@ -126,7 +117,7 @@ int drm_legacy_sg_alloc(struct drm_device *dev, void *data, > > return -ENOMEM; > > } > > > > - entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT); > > + entry->virtual = vmalloc_32(pages << PAGE_SHIFT); > > if (!entry->virtual) { > > kfree(entry->busaddr); > > kfree(entry->pagelist); > > -- > > 2.25.1 > > > >