From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:57860 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753798Ab2DFPMw (ORCPT ); Fri, 6 Apr 2012 11:12:52 -0400 From: Laurent Pinchart To: Tomasz Stanislawski Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, airlied@redhat.com, m.szyprowski@samsung.com, kyungmin.park@samsung.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, Sumit Semwal Subject: Re: [PATCH 11/11] v4l: vb2: Add dma-contig allocator as dma_buf user Date: Fri, 06 Apr 2012 17:12:56 +0200 Message-ID: <3806078.bLkgp7kyMX@avalon> In-Reply-To: <1333634408-4960-12-git-send-email-t.stanislaws@samsung.com> References: <1333634408-4960-1-git-send-email-t.stanislaws@samsung.com> <1333634408-4960-12-git-send-email-t.stanislaws@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Tomasz, On Thursday 05 April 2012 16:00:08 Tomasz Stanislawski wrote: > From: Sumit Semwal > > This patch makes changes for adding dma-contig as a dma_buf user. It > provides function implementations for the {attach, detach, map, > unmap}_dmabuf() mem_ops of DMABUF memory type. > > Signed-off-by: Sumit Semwal > Signed-off-by: Sumit Semwal > [author of the original patch] > Signed-off-by: Tomasz Stanislawski > [integration with refactored dma-contig allocator] > --- > drivers/media/video/videobuf2-dma-contig.c | 117 +++++++++++++++++++++++++ > 1 files changed, 117 insertions(+), 0 deletions(-) > > diff --git a/drivers/media/video/videobuf2-dma-contig.c > b/drivers/media/video/videobuf2-dma-contig.c index 30f316588..6329483 > 100644 > --- a/drivers/media/video/videobuf2-dma-contig.c > +++ b/drivers/media/video/videobuf2-dma-contig.c > @@ -10,6 +10,7 @@ > * the Free Software Foundation. > */ > > +#include > #include > #include > #include > @@ -33,6 +34,9 @@ struct vb2_dc_buf { > > /* USERPTR related */ > struct vm_area_struct *vma; > + > + /* DMABUF related */ > + struct dma_buf_attachment *db_attach; > }; > > /*********************************************/ > @@ -425,6 +429,115 @@ fail_buf: > } > > /*********************************************/ > +/* callbacks for DMABUF buffers */ > +/*********************************************/ > + > +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; > + > + if (WARN_ON(!buf->db_attach)) { > + printk(KERN_ERR "trying to pin a non attached buffer\n"); > + return -EINVAL; > + } > + > + if (WARN_ON(buf->dma_sgt)) { > + printk(KERN_ERR "dmabuf buffer is already pinned\n"); > + return 0; > + } > + > + /* get the associated scatterlist for this buffer */ > + sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir); > + if (IS_ERR_OR_NULL(sgt)) { > + printk(KERN_ERR "Error getting dmabuf scatterlist\n"); > + return -EINVAL; > + } > + > + /* 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; The fail_map label is only used here, you can move the dma_buf_unmap_attachment() call here and return -EFAULT directly. > + } > + > + buf->dma_addr = sg_dma_address(sgt->sgl); > + buf->dma_sgt = sgt; > + > + return 0; > + > +fail_map: > + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); > + > + return ret; > +} > + > +static void vb2_dc_unmap_dmabuf(void *mem_priv) > +{ > + struct vb2_dc_buf *buf = mem_priv; > + struct sg_table *sgt = buf->dma_sgt; > + > + if (WARN_ON(!buf->db_attach)) { > + printk(KERN_ERR "trying to unpin a not attached buffer\n"); > + return; > + } > + > + if (WARN_ON(!sgt)) { > + printk(KERN_ERR "dmabuf buffer is already unpinned\n"); > + return; > + } > + > + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); > + > + buf->dma_addr = 0; > + buf->dma_sgt = NULL; > +} > + > +static void vb2_dc_detach_dmabuf(void *mem_priv) > +{ > + struct vb2_dc_buf *buf = mem_priv; > + > + if (buf->dma_addr) > + vb2_dc_unmap_dmabuf(buf); What would you think about calling vb2_dc_unmap_dmabuf() from vb2 core instead, to keep the map/unmap calls symmetrical (the second WARN_ON and the related printk in vb2_dc_unmap_dmabuf() might need to go then) ? > + /* detach this attachment */ > + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); > + kfree(buf); > +} > + > +static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, > + unsigned long size, int write) > +{ > + struct vb2_dc_buf *buf; > + struct dma_buf_attachment *dba; > + > + if (dbuf->size < size) > + return ERR_PTR(-EFAULT); > + > + buf = kzalloc(sizeof *buf, GFP_KERNEL); > + if (!buf) > + return ERR_PTR(-ENOMEM); > + > + buf->dev = alloc_ctx; > + /* create attachment for the dmabuf with the user device */ > + dba = dma_buf_attach(dbuf, buf->dev); > + if (IS_ERR(dba)) { > + printk(KERN_ERR "failed to attach dmabuf\n"); > + kfree(buf); > + return dba; > + } > + > + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; > + buf->size = size; > + buf->db_attach = dba; > + > + return buf; > +} > + > +/*********************************************/ > /* DMA CONTIG exported functions */ > /*********************************************/ > > @@ -438,6 +551,10 @@ const struct vb2_mem_ops vb2_dma_contig_memops = { > .put_userptr = vb2_dc_put_userptr, > .prepare = vb2_dc_prepare, > .finish = vb2_dc_finish, > + .map_dmabuf = vb2_dc_map_dmabuf, > + .unmap_dmabuf = vb2_dc_unmap_dmabuf, > + .attach_dmabuf = vb2_dc_attach_dmabuf, > + .detach_dmabuf = vb2_dc_detach_dmabuf, > .num_users = vb2_dc_num_users, > }; > EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); -- Regards, Laurent Pinchart