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=-18.2 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,USER_AGENT_SANE_1 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 B8194C07E95 for ; Fri, 16 Jul 2021 15:29:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95682613F6 for ; Fri, 16 Jul 2021 15:29:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240736AbhGPPcw (ORCPT ); Fri, 16 Jul 2021 11:32:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:54360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240361AbhGPPcu (ORCPT ); Fri, 16 Jul 2021 11:32:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5133E613E3; Fri, 16 Jul 2021 15:29:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626449395; bh=gwbpEM2I/t3yULslsQrJ4ImN5wzlSWPQIZoIz0IW+1s=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=f4ofUif5kH18TRPd4Y5z3aE1G7LQpbotUnjc8VuGp2I0yUtnZmdrMkMmoSR88EIa+ 93kwmtIAUZ+oxmpJDNFFwxMEHn0SbGInIDxf63X8rFRBR/PMU2qW79TzYbsdKUXP6E TUlYwbBlP/kaK9xxZMt+hsAHUqpt7w2RQi8IUzGxo22CMlgSQ1xq/KON5g8oKnjDtG K1m2MpWwWkYQGM59WC2at2zpyln+B+Pz1po9li/5AK7BX73kdWyYxj8uTBAb1OJoMe bW9dDdfbJ+KUVFSQqbzf2kBoLOQu77gYyJ+5VtTHbUVbGYj6U6W33FpA43P3eumjUD 88TIOyOE730zQ== Date: Fri, 16 Jul 2021 08:29:54 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Roman Skakun cc: Christoph Hellwig , Stefano Stabellini , Boris Ostrovsky , Konrad Rzeszutek Wilk , Juergen Gross , xen-devel@lists.xenproject.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Oleksandr Tyshchenko , Oleksandr Andrushchenko , Volodymyr Babchuk , Andrii Anisov , Roman Skakun Subject: Re: [PATCH v2] dma-mapping: use vmalloc_to_page for vmalloc addresses In-Reply-To: Message-ID: References: <20210715170011.GA17324@lst.de> <20210716083934.154992-1-rm.skakun@gmail.com> <20210716093551.GA17981@lst.de> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-2042327733-1626449395=:3916" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-2042327733-1626449395=:3916 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Fri, 16 Jul 2021, Roman Skakun wrote: > > Technically this looks good. But given that exposing a helper > > that does either vmalloc_to_page or virt_to_page is one of the > > never ending MM discussions I don't want to get into that discussion > > and just keep it local in the DMA code. > > > > Are you fine with me applying this version? > > Looks good to me, thanks! > But, Stefano asked me about using created helper in the > xen_swiotlb_free_coherent() > and I created a patch according to this mention. > > We can merge this patch and create a new one for > xen_swiotlb_free_coherent() later. Yeah, no worries, I didn't know that exposing dma_common_vaddr_to_page was problematic. This patch is fine by me. > пт, 16 июл. 2021 г. в 12:35, Christoph Hellwig : > > > > Technically this looks good. But given that exposing a helper > > that does either vmalloc_to_page or virt_to_page is one of the > > never ending MM discussions I don't want to get into that discussion > > and just keep it local in the DMA code. > > > > Are you fine with me applying this version? > > > > --- > > From 40ac971eab89330d6153e7721e88acd2d98833f9 Mon Sep 17 00:00:00 2001 > > From: Roman Skakun > > Date: Fri, 16 Jul 2021 11:39:34 +0300 > > Subject: dma-mapping: handle vmalloc addresses in > > dma_common_{mmap,get_sgtable} > > > > xen-swiotlb can use vmalloc backed addresses for dma coherent allocations > > and uses the common helpers. Properly handle them to unbreak Xen on > > ARM platforms. > > > > Fixes: 1b65c4e5a9af ("swiotlb-xen: use xen_alloc/free_coherent_pages") > > Signed-off-by: Roman Skakun > > Reviewed-by: Andrii Anisov > > [hch: split the patch, renamed the helpers] > > Signed-off-by: Christoph Hellwig > > --- > > kernel/dma/ops_helpers.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > > index 910ae69cae77..af4a6ef48ce0 100644 > > --- a/kernel/dma/ops_helpers.c > > +++ b/kernel/dma/ops_helpers.c > > @@ -5,6 +5,13 @@ > > */ > > #include > > > > +static struct page *dma_common_vaddr_to_page(void *cpu_addr) > > +{ > > + if (is_vmalloc_addr(cpu_addr)) > > + return vmalloc_to_page(cpu_addr); > > + return virt_to_page(cpu_addr); > > +} > > + > > /* > > * Create scatter-list for the already allocated DMA buffer. > > */ > > @@ -12,7 +19,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > > void *cpu_addr, dma_addr_t dma_addr, size_t size, > > unsigned long attrs) > > { > > - struct page *page = virt_to_page(cpu_addr); > > + struct page *page = dma_common_vaddr_to_page(cpu_addr); > > int ret; > > > > ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > > @@ -32,6 +39,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > > unsigned long user_count = vma_pages(vma); > > unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; > > unsigned long off = vma->vm_pgoff; > > + struct page *page = dma_common_vaddr_to_page(cpu_addr); > > int ret = -ENXIO; > > > > vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); > > @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > > return -ENXIO; > > > > return remap_pfn_range(vma, vma->vm_start, > > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > > + page_to_pfn(page) + vma->vm_pgoff, > > user_count << PAGE_SHIFT, vma->vm_page_prot); > > #else > > return -ENXIO; > > -- > > 2.30.2 > > > > > -- > Best Regards, Roman. > --8323329-2042327733-1626449395=:3916--