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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A9382C49EA5 for ; Fri, 25 Jun 2021 03:10:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91749613FA for ; Fri, 25 Jun 2021 03:10:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233089AbhFYDM6 (ORCPT ); Thu, 24 Jun 2021 23:12:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232973AbhFYDMz (ORCPT ); Thu, 24 Jun 2021 23:12:55 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D11B1C061756 for ; Thu, 24 Jun 2021 20:10:35 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id i6so6923516pfq.1 for ; Thu, 24 Jun 2021 20:10:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=EHF4hXE1BofxiNAxyTu0OOal5JJOm5OszXgmCJK9iiA=; b=f4nq0N9EujiAI6HzSt7qwQNFrzIXuOou3PVS9akh+S1P7E555UZxrGQXPU9uZ2fNic BJbUrlVDNCCZByRe0KeNEkMol6uYdlYFRyuCR5tW1WVMTcXibXI6MlNQIsT1LgiRu72e c4QLDt2mQjVTMN4grbZRyJM950p5BhOcdA2DQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=EHF4hXE1BofxiNAxyTu0OOal5JJOm5OszXgmCJK9iiA=; b=RrdMIS/fFJr6pisESy8TGaw80+I5H6UhZfHj+gRI7HxT8jdTtrCE1+23Mngw71dJ11 2plaMLEQuCke0ToyNNyhSUbuo3XwuDn3OmchtSaQLXZyzBlCleEq4gzYeL3uEm+fmWEk NumVt5k2hL5GYTBuJv/eAVl9vOIekX54vL3xQtRABI0P2OJkhN3hiWKqHYWgRQz7hyPy x8L4Q72xbU9n8BB4n7iQ0WiThWVy/E5s/BuisBYsqxJqqu9zujSgsYnudbobrDsg2SGk lmLkFzFdbvIk/Sfbw3HSvyt8Cma2HbwVHQNM5H0jik0bW8RRu71bomRdykX1sTcCnx7d S6Yw== X-Gm-Message-State: AOAM530kbxvUOG/MVBb1aBStB4WGbr7+dX2FdhMZbAV3uyV3Q8Lj2Bna xf4qA6/eZJJZwlTmQ2w5DA+zGQ== X-Google-Smtp-Source: ABdhPJyXehUV2SIhmH5Jr3Xh7AXmXjKpVWqO1MypdP0+F+Ezg1KAhPoQeVFlvjROnlIm4K4WIuKVNQ== X-Received: by 2002:a63:ef44:: with SMTP id c4mr7433314pgk.162.1624590635359; Thu, 24 Jun 2021 20:10:35 -0700 (PDT) Received: from google.com ([2409:10:2e40:5100:86d5:e5c:bdd4:774f]) by smtp.gmail.com with ESMTPSA id o9sm4323763pfh.217.2021.06.24.20.10.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Jun 2021 20:10:34 -0700 (PDT) Date: Fri, 25 Jun 2021 12:10:30 +0900 From: Sergey Senozhatsky To: Hans Verkuil Cc: Tomasz Figa , Ricardo Ribalda , Christoph Hellwig , Mauro Carvalho Chehab , Sergey Senozhatsky , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 8/8] videobuf2: handle non-contiguous DMA allocations Message-ID: References: <20210427131344.139443-1-senozhatsky@chromium.org> <20210427131344.139443-9-senozhatsky@chromium.org> <10a0903a-e295-5cba-683a-1eb89a0804ed@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hans, On (21/06/17 16:56), Sergey Senozhatsky wrote: [..] > static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv) > { > struct vb2_dc_buf *buf = buf_priv; > > if (buf->vaddr) > return buf->vaddr; > > if (buf->db_attach) { > struct dma_buf_map map; > > if (!dma_buf_vmap(buf->db_attach->dmabuf, &map)) > buf->vaddr = map.vaddr; > > return buf->vaddr; > } > > if (!buf->coherent_mem) > buf->vaddr = dma_vmap_noncontiguous(buf->dev, buf->size, > buf->dma_sgt); > return buf->vaddr; > } > > And in vb2_dc_alloc functions set vaddr for !DMA_ATTR_NO_KERNEL_MAPPING > in both coherent and non-coherent. So that we probably can have less > branches when ->vaddr is NULL for one type of allocations, and is not > NULL for another. > > static int vb2_dc_alloc_coherent(struct vb2_dc_buf *buf) > { > struct vb2_queue *q = buf->vb->vb2_queue; > > buf->cookie = dma_alloc_attrs(buf->dev, > buf->size, > &buf->dma_addr, > GFP_KERNEL | q->gfp_flags, > buf->attrs); > if (!buf->cookie) > return -ENOMEM; > > if (q->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING) > return 0; > > buf->vaddr = buf->cookie; > return 0; > } > > static int vb2_dc_alloc_non_coherent(struct vb2_dc_buf *buf) > { > struct vb2_queue *q = buf->vb->vb2_queue; > > buf->dma_sgt = dma_alloc_noncontiguous(buf->dev, > buf->size, > buf->dma_dir, > GFP_KERNEL | q->gfp_flags, > buf->attrs); > if (!buf->dma_sgt) > return -ENOMEM; > > if (q->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING) > return 0; > > buf->vaddr = dma_vmap_noncontiguous(buf->dev, buf->size, buf->dma_sgt); > if (!buf->vaddr) { > dma_free_noncontiguous(buf->dev, buf->size, > buf->dma_sgt, buf->dma_addr); > return -ENOMEM; > } > return 0; > } I guess this should address the case when "after allocating the buffer, the buffer is exported as a dma_buf and another device calls dma_buf_ops vb2_dc_dmabuf_ops_vmap, which in turn calls dma_buf_map_set_vaddr(map, buf->vaddr); with a NULL buf->vaddr" Because ->vaddr will not be NULL now after allocation for both coherent and non-coherent buffers (modulo DMA_ATTR_NO_KERNEL_MAPPING requests). What do you think?