From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:16881 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758702Ab2DJNK5 (ORCPT ); Tue, 10 Apr 2012 09:10:57 -0400 Received: from euspt2 (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 <0M2900LLSLWHV7@mailout1.w1.samsung.com> for linux-media@vger.kernel.org; Tue, 10 Apr 2012 14:09:54 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0M2900ML3LY1QL@spt2.w1.samsung.com> for linux-media@vger.kernel.org; Tue, 10 Apr 2012 14:10:50 +0100 (BST) Date: Tue, 10 Apr 2012 15:10:39 +0200 From: Tomasz Stanislawski Subject: [RFC 05/13] v4l: vb2-dma-contig: add support for DMABUF exporting In-reply-to: <1334063447-16824-1-git-send-email-t.stanislaws@samsung.com> To: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: airlied@redhat.com, m.szyprowski@samsung.com, t.stanislaws@samsung.com, kyungmin.park@samsung.com, laurent.pinchart@ideasonboard.com, sumit.semwal@ti.com, daeinki@gmail.com, daniel.vetter@ffwll.ch, robdclark@gmail.com, pawel@osciak.com, linaro-mm-sig@lists.linaro.org, subashrp@gmail.com, mchehab@redhat.com Message-id: <1334063447-16824-6-git-send-email-t.stanislaws@samsung.com> MIME-version: 1.0 Content-type: TEXT/PLAIN Content-transfer-encoding: 7BIT References: <1334063447-16824-1-git-send-email-t.stanislaws@samsung.com> Sender: linux-media-owner@vger.kernel.org List-ID: This patch adds support for exporting a dma-contig buffer using DMABUF interface. Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park --- drivers/media/video/videobuf2-dma-contig.c | 128 ++++++++++++++++++++++++++++ 1 files changed, 128 insertions(+), 0 deletions(-) diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index 0cdcd2b..e1ad47e 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -31,6 +31,7 @@ struct vb2_dc_buf { /* MMAP related */ struct vb2_vmarea_handler handler; atomic_t refcount; + struct dma_buf *dma_buf; struct sg_table *sgt_base; /* USERPTR related */ @@ -190,6 +191,8 @@ static void vb2_dc_put(void *buf_priv) if (!atomic_dec_and_test(&buf->refcount)) return; + if (buf->dma_buf) + dma_buf_put(buf->dma_buf); vb2_dc_release_sgtable(buf->sgt_base); dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr); kfree(buf); @@ -306,6 +309,130 @@ 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) +{ + /* nothing to be done */ + return 0; +} + +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; + + if (!attach) + return; + + sgt = &attach->sgt; + + dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->nents, attach->dir); + sg_free_table(sgt); + kfree(attach); + db_attach->priv = NULL; +} + +static struct sg_table *vb2_dc_dmabuf_ops_map( + struct dma_buf_attachment *db_attach, enum dma_data_direction dir) +{ + 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 scatterlist *rd, *wr; + int i, ret; + + /* return previously mapped sg table */ + if (attach) + return &attach->sgt; + + attach = kzalloc(sizeof *attach, GFP_KERNEL); + if (!attach) + 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); + return ERR_PTR(-ENOMEM); + } + + rd = buf->sgt_base->sgl; + wr = sgt->sgl; + for (i = 0; i < sgt->orig_nents; ++i) { + sg_set_page(wr, sg_page(rd), rd->length, rd->offset); + rd = sg_next(rd); + 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; + + return sgt; +} + +static void vb2_dc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, + struct sg_table *sgt, enum dma_data_direction dir) +{ + /* nothing to be done here */ +} + +static void vb2_dc_dmabuf_ops_release(struct dma_buf *dbuf) +{ + /* drop reference obtained in vb2_dc_get_dmabuf */ + vb2_dc_put(dbuf->priv); +} + +static struct dma_buf_ops vb2_dc_dmabuf_ops = { + .attach = vb2_dc_dmabuf_ops_attach, + .detach = vb2_dc_dmabuf_ops_detach, + .map_dma_buf = vb2_dc_dmabuf_ops_map, + .unmap_dma_buf = vb2_dc_dmabuf_ops_unmap, + .release = vb2_dc_dmabuf_ops_release, +}; + +static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + struct dma_buf *dbuf; + + if (buf->dma_buf) + return buf->dma_buf; + + /* dmabuf keeps reference to vb2 buffer */ + atomic_inc(&buf->refcount); + dbuf = dma_buf_export(buf, &vb2_dc_dmabuf_ops, buf->size, 0); + if (IS_ERR(dbuf)) { + atomic_dec(&buf->refcount); + return NULL; + } + + buf->dma_buf = dbuf; + + return dbuf; +} + +/*********************************************/ /* callbacks for USERPTR buffers */ /*********************************************/ @@ -615,6 +742,7 @@ static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, const struct vb2_mem_ops vb2_dma_contig_memops = { .alloc = vb2_dc_alloc, .put = vb2_dc_put, + .get_dmabuf = vb2_dc_get_dmabuf, .cookie = vb2_dc_cookie, .vaddr = vb2_dc_vaddr, .mmap = vb2_dc_mmap, -- 1.7.5.4