From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Stanislawski Subject: [RFCv2 PATCH 7/9] v4l: vb2-dma-contig: change map/unmap behaviour Date: Tue, 13 Mar 2012 11:17:05 +0100 Message-ID: <1331633827-503-8-git-send-email-t.stanislaws@samsung.com> References: <1331633827-503-1-git-send-email-t.stanislaws@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.w1.samsung.com (mailout1.w1.samsung.com [210.118.77.11]) by gabe.freedesktop.org (Postfix) with ESMTP id 8A4E89EFA7 for ; Tue, 13 Mar 2012 03:17:16 -0700 (PDT) Received: from euspt1 (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTP id <0M0T007CGJ8KJ3@mailout1.w1.samsung.com> for dri-devel@lists.freedesktop.org; Tue, 13 Mar 2012 10:17:09 +0000 (GMT) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0M0T00IYUJ8N5N@spt1.w1.samsung.com> for dri-devel@lists.freedesktop.org; Tue, 13 Mar 2012 10:17:12 +0000 (GMT) In-reply-to: <1331633827-503-1-git-send-email-t.stanislaws@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: dri-devel@lists.freedesktop.org Cc: t.stanislaws@samsung.com, ben@bwidawsk.net, daniel.vetter@ffwll.ch, linaro-mm-sig@lists.linaro.org, kyungmin.park@samsung.com, sakari.ailus@iki.fi, airlied@redhat.com, m.szyprowski@samsung.com List-Id: dri-devel@lists.freedesktop.org The DMABUF documentation says that the map_dma_buf callback should return scatterlist that is mapped into a caller's address space. In practice, almost none of existing implementations of DMABUF exporter does it. This patch breaks the DMABUF specification in order to allow exchange DMABUF buffers between other APIs like DRM. Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park --- drivers/media/video/videobuf2-dma-contig.c | 64 ++++++++++++---------------- 1 files changed, 27 insertions(+), 37 deletions(-) diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index d95b23a..32bb16b 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -315,11 +315,6 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) /* DMABUF ops for exporters */ /*********************************************/ -struct vb2_dc_attachment { - struct sg_table sgt; - enum dma_data_direction dir; -}; - static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev, struct dma_buf_attachment *dbuf_attach) { @@ -330,17 +325,13 @@ static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev, static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf, struct dma_buf_attachment *db_attach) { - struct vb2_dc_attachment *attach = db_attach->priv; - struct sg_table *sgt; + struct sg_table *sgt = db_attach->priv; - if (!attach) + if (!sgt) return; - sgt = &attach->sgt; - - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->nents, attach->dir); sg_free_table(sgt); - kfree(attach); + kfree(sgt); db_attach->priv = NULL; } @@ -349,26 +340,22 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( { struct dma_buf *dbuf = db_attach->dmabuf; struct vb2_dc_buf *buf = dbuf->priv; - struct vb2_dc_attachment *attach = db_attach->priv; - struct sg_table *sgt; + struct sg_table *sgt = db_attach->priv; struct scatterlist *rd, *wr; int i, ret; /* return previously mapped sg table */ - if (attach) - return &attach->sgt; + if (sgt) + return sgt; - attach = kzalloc(sizeof *attach, GFP_KERNEL); - if (!attach) + sgt = kzalloc(sizeof *sgt, GFP_KERNEL); + if (!sgt) return ERR_PTR(-ENOMEM); - sgt = &attach->sgt; - attach->dir = dir; - /* copying the buf->base_sgt to attachment */ ret = sg_alloc_table(sgt, buf->sgt_base->orig_nents, GFP_KERNEL); if (ret) { - kfree(attach); + kfree(sgt); return ERR_PTR(-ENOMEM); } @@ -380,16 +367,7 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( wr = sg_next(wr); } - /* mapping new sglist to the client */ - ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dir); - if (ret <= 0) { - printk(KERN_ERR "failed to map scatterlist\n"); - sg_free_table(sgt); - kfree(attach); - return ERR_PTR(-EIO); - } - - db_attach->priv = attach; + db_attach->priv = sgt; return sgt; } @@ -623,7 +601,7 @@ static int vb2_dc_map_dmabuf(void *mem_priv) struct vb2_dc_buf *buf = mem_priv; struct sg_table *sgt; unsigned long contig_size; - int ret = 0; + int ret = -EFAULT; if (WARN_ON(!buf->db_attach)) { printk(KERN_ERR "trying to pin a non attached buffer\n"); @@ -642,12 +620,20 @@ static int vb2_dc_map_dmabuf(void *mem_priv) return -EINVAL; } + /* mapping new sglist to the client */ + sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents, + buf->dma_dir); + if (sgt->nents <= 0) { + printk(KERN_ERR "failed to map scatterlist\n"); + goto fail_map_attachment; + } + /* checking if dmabuf is big enough to store contiguous chunk */ contig_size = vb2_dc_get_contiguous_size(sgt); if (contig_size < buf->size) { - printk(KERN_ERR "contiguous chunk of dmabuf is too small\n"); - ret = -EFAULT; - goto fail_map; + printk(KERN_ERR "contiguous chunk of dmabuf is too small " + "%lu/%lu bytes\n", contig_size, buf->size); + goto fail_map_sg; } buf->dma_addr = sg_dma_address(sgt->sgl); @@ -655,7 +641,10 @@ static int vb2_dc_map_dmabuf(void *mem_priv) return 0; -fail_map: +fail_map_sg: + dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + +fail_map_attachment: dma_buf_unmap_attachment(buf->db_attach, sgt); return ret; @@ -676,6 +665,7 @@ static void vb2_dc_unmap_dmabuf(void *mem_priv) return; } + dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); dma_buf_unmap_attachment(buf->db_attach, sgt); buf->dma_addr = 0; -- 1.7.5.4