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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80912C4332F for ; Sun, 13 Nov 2022 16:27:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235320AbiKMQ1d (ORCPT ); Sun, 13 Nov 2022 11:27:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233794AbiKMQ13 (ORCPT ); Sun, 13 Nov 2022 11:27:29 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D85025FFE; Sun, 13 Nov 2022 08:27:28 -0800 (PST) Received: from [192.168.2.125] (unknown [109.252.117.140]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 6E46F660036D; Sun, 13 Nov 2022 16:27:26 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1668356847; bh=depGYhwkKPmSm4U0mvWNMVYV3VfG81IAL1hmomv9Y0g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=gFZK+iuy/tTCaxzkIzB0TWH9EBcISskrDZy5noHC46JFBCkB8r5rIr1p9M9Full0S 9vJ5IdE+f3O2K/qhP95QoSOohhWeiLXsobZXetARESBFvl5231xj+FVyA10Yx2LBw6 GCNvRZnvwN32PbFTTDU33gHQlK9VJaPuKhpYRaacjataB6C/Dz/mMDtPeZrr9WJZwU 7Yi4BOaJNe68nA0bwPaO31AF4tghE8T30uf5fnImRIym3JiJ/E61qkovRtOe94B9+9 dl/39/9dUzeSxI2rUgqYkHoMo0IlrXXjHwYBykC9mNdIhuNtHwJzzrs1Dsvl8qFUCZ 1O69e41WwciqQ== Message-ID: <69cff33f-fd6e-f931-c469-a383d816b956@collabora.com> Date: Sun, 13 Nov 2022 19:27:22 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.0 Subject: Re: [PATCH v2] udmabuf: add vmap method to udmabuf_ops To: Lukasz Wiecaszek , Gerd Hoffmann Cc: Lukasz Wiecaszek , kernel test robot , Sumit Semwal , =?UTF-8?Q?Christian_K=c3=b6nig?= , dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org References: <20221113150511.8878-1-lukasz.wiecaszek@gmail.com> Content-Language: en-US From: Dmitry Osipenko In-Reply-To: <20221113150511.8878-1-lukasz.wiecaszek@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/13/22 18:05, Lukasz Wiecaszek wrote: > The reason behind that patch is associated with videobuf2 subsystem > (or more genrally with v4l2 framework) and user created > dma buffers (udmabuf). In some circumstances > when dealing with V4L2_MEMORY_DMABUF buffers videobuf2 subsystem > wants to use dma_buf_vmap() method on the attached dma buffer. > As udmabuf does not have .vmap operation implemented, > such dma_buf_vmap() natually fails. > > videobuf2_common: [cap-000000003473b2f1] __vb2_queue_alloc: allocated 3 buffers, 1 plane(s) each > videobuf2_common: [cap-000000003473b2f1] __prepare_dmabuf: buffer for plane 0 changed > videobuf2_common: [cap-000000003473b2f1] __prepare_dmabuf: failed to map dmabuf for plane 0 > videobuf2_common: [cap-000000003473b2f1] __buf_prepare: buffer preparation failed: -14 > > The patch itself seems to be strighforward. > It adds implementation of .vmap method to 'struct dma_buf_ops udmabuf_ops'. > .vmap method itself uses vm_map_ram() to map pages linearly > into the kernel virtual address space (only if such mapping > hasn't been created yet). > > Signed-off-by: Lukasz Wiecaszek > Reported-by: kernel test robot > --- > v1: https://lore.kernel.org/linux-media/202211120352.G7WPASoP-lkp@intel.com/T/#t > > v1 -> v2: Patch prepared and tested against 6.1.0-rc2+ > > drivers/dma-buf/udmabuf.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c > index 2bcdb935a3ac..2ca0e3639360 100644 > --- a/drivers/dma-buf/udmabuf.c > +++ b/drivers/dma-buf/udmabuf.c > @@ -12,6 +12,8 @@ > #include > #include > #include > +#include > +#include > > static int list_limit = 1024; > module_param(list_limit, int, 0644); > @@ -26,6 +28,7 @@ struct udmabuf { > struct page **pages; > struct sg_table *sg; > struct miscdevice *device; > + void *vaddr; > }; > > static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) > @@ -57,6 +60,21 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) > return 0; > } > > +static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map) > +{ > + struct udmabuf *ubuf = buf->priv; > + > + if (!ubuf->vaddr) { > + ubuf->vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1); > + if (!ubuf->vaddr) > + return -EINVAL; > + } > + > + iosys_map_set_vaddr(map, ubuf->vaddr); > + > + return 0; > +} > + > static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf, > enum dma_data_direction direction) > { > @@ -159,6 +177,7 @@ static const struct dma_buf_ops udmabuf_ops = { > .unmap_dma_buf = unmap_udmabuf, > .release = release_udmabuf, > .mmap = mmap_udmabuf, > + .vmap = vmap_udmabuf, > .begin_cpu_access = begin_cpu_udmabuf, > .end_cpu_access = end_cpu_udmabuf, > }; Where is vunmap? -- Best regards, Dmitry