From patchwork Tue Nov 15 20:04:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Wiecaszek X-Patchwork-Id: 624994 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 B2F51C433FE for ; Tue, 15 Nov 2022 20:05:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231381AbiKOUFu (ORCPT ); Tue, 15 Nov 2022 15:05:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230236AbiKOUFt (ORCPT ); Tue, 15 Nov 2022 15:05:49 -0500 Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BBC6C77A; Tue, 15 Nov 2022 12:05:47 -0800 (PST) Received: by mail-lj1-x22b.google.com with SMTP id l8so19004016ljh.13; Tue, 15 Nov 2022 12:05:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Y3n9eTzyovuImpyqmAEmozCytKhOiLUTsASX6dM4moQ=; b=SHSAvtomDRH42ON709sBLl59XSWVsQy34EfQhfVbSa08rIXrY84R4COytoYvMmr1D1 e81p11b2gX1IxLp1Wk3EkpuupEzk/0g0oEX+s/Xo9NDE8m7Y/DrAO/I7u/1IQNqQ7brM z7GcVDKVktm0xwphBqywkq2JL0Sl/h/v9YrR/zfFOmyKDg1rGnrI3hYQTexcbuj67QiH 2d7TPxNf1woM7AXMXa0qxMhpJl+sDCjl1+WpbKEPOB22Dkw3yERFVMZsq6xKyyzmvog9 xMGJv7WgIGWmBi+2AlBz4d4c6vWTcA7c+xO9LI2oe1m94jw589WP/uY5i7EHwlS6RkEv Fr0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Y3n9eTzyovuImpyqmAEmozCytKhOiLUTsASX6dM4moQ=; b=Lq1q8ORnzl5Ffx2u5NmyZ2smEv9Qo1pE8BK449OdaqBsRhlYe7ynCSNlhLTfMN8oFg 2z53MXXAYs0X37fEDqT9q24eBWpZvviXgN7wgBD3benGy5nYZdfvt/hc17TUF2sWILZJ NX8w8KSBth4odZN4zcX3oWsowUu8jzs+0rkPl9MxW4/bdPusUVySS/RZ9ECHvdYnybEo P1IqfRYm7KGxxlV+EFry5Iqo9eyRP1DVej6eDbSP/KWJIVnIg+36Q9UdFv+RMKd92T2e my4fwKxRPpGhLvg+KSd7H888Ikv0+m6VZznlP2Q8G0/vedqDF9Z32Jo4VL4IMVCiRdIf 0FhQ== X-Gm-Message-State: ANoB5pngQaBh1x5o5IXbAbD0dxsEcdMGwGauRBrywtiTdNcJmst+pN1M uxexTv1TsFx7kzz3IaLNd6Y= X-Google-Smtp-Source: AA0mqf5jt+shThPbnx0wtDVLw2x666FkmDvA0ANREZf/u2AiwQmmMNKF+SrjKK9g7V3hpCfvUArtew== X-Received: by 2002:a2e:940a:0:b0:278:ecbe:ebba with SMTP id i10-20020a2e940a000000b00278ecbeebbamr6252965ljh.450.1668542745717; Tue, 15 Nov 2022 12:05:45 -0800 (PST) Received: from localhost.localdomain ([78.133.163.249]) by smtp.googlemail.com with ESMTPSA id h8-20020ac24da8000000b004ad5f5c2b28sm2308586lfe.119.2022.11.15.12.05.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 12:05:45 -0800 (PST) From: Lukasz Wiecaszek X-Google-Original-From: Lukasz Wiecaszek To: Gerd Hoffmann Cc: Dmitry Osipenko , 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 Subject: [PATCH v3] udmabuf: add vmap and vunmap methods to udmabuf_ops Date: Tue, 15 Nov 2022 21:04:26 +0100 Message-Id: <20221115200426.4801-1-lukasz.wiecaszek@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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: __vb2_queue_alloc: allocated 3 buffers, 1 plane(s) each videobuf2_common: __prepare_dmabuf: buffer for plane 0 changed videobuf2_common: __prepare_dmabuf: failed to map dmabuf for plane 0 videobuf2_common: __buf_prepare: buffer preparation failed: -14 The patch itself seems to be strighforward. It adds implementation of .vmap and .vunmap methods to 'struct dma_buf_ops udmabuf_ops'. .vmap method itself uses vm_map_ram() to map pages linearly into the kernel virtual address space. .vunmap removes mapping created earlier by .vmap. All locking and 'vmapping counting' is done in dma_buf.c so it seems to be redundant/unnecessary in .vmap/.vunmap. Signed-off-by: Lukasz Wiecaszek Reported-by: kernel test robot --- v1: https://lore.kernel.org/linux-media/202211120352.G7WPASoP-lkp@intel.com/T/#t v2: https://lore.kernel.org/linux-media/20221114052944.GA7264@thinkpad-p72/T/#t v2 -> v3: Added .vunmap to 'struct dma_buf_ops udmabuf_ops' v1 -> v2: Patch prepared and tested against 6.1.0-rc2+ drivers/dma-buf/udmabuf.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 283816fbd72f..740d6e426ee9 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include static int list_limit = 1024; module_param(list_limit, int, 0644); @@ -60,6 +62,30 @@ 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; + void *vaddr; + + dma_resv_assert_held(buf->resv); + + vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1); + if (!vaddr) + return -EINVAL; + + iosys_map_set_vaddr(map, vaddr); + return 0; +} + +static void vunmap_udmabuf(struct dma_buf *buf, struct iosys_map *map) +{ + struct udmabuf *ubuf = buf->priv; + + dma_resv_assert_held(buf->resv); + + vm_unmap_ram(map->vaddr, ubuf->pagecount); +} + static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf, enum dma_data_direction direction) { @@ -162,6 +188,8 @@ static const struct dma_buf_ops udmabuf_ops = { .unmap_dma_buf = unmap_udmabuf, .release = release_udmabuf, .mmap = mmap_udmabuf, + .vmap = vmap_udmabuf, + .vunmap = vunmap_udmabuf, .begin_cpu_access = begin_cpu_udmabuf, .end_cpu_access = end_cpu_udmabuf, };