Hi Doug, Is there any reason to think that different planes will need different DMA attrs? I ask because this patch series of mine:
http://www.spinics.net/lists/linux-media/msg97522.html does away with allocating allocation contexts (struct vb2_dc_conf). For dma_attr this would mean that struct dma_attrs would probably be implemented as a struct dma_attrs pointer in the vb2_queue struct once I rebase that patch series on top of this patch. In other words, the same dma_attrs struct would be used for all planes. Second question: would specifying dma_attrs also make sense for videobuf2-dma-sg.c? Regards, Hans On 01/11/2016 06:30 PM, Douglas Anderson wrote: > From: Tomasz Figa <tf...@chromium.org> > > DMA allocations might be subject to certain reqiurements specific to the > hardware using the buffers, such as availability of kernel mapping (for > contents fix-ups in the driver). The only entity that knows them is the > driver, so it must share this knowledge with vb2-dc. > > This patch extends the alloc_ctx initialization interface to let the > driver specify DMA attrs, which are then stored inside the allocation > context and will be used for all allocations with that context. > > As a side effect, all dma_*_coherent() calls are turned into > dma_*_attrs() calls, because the attributes need to be carried over > through all DMA operations. > > Signed-off-by: Tomasz Figa <tf...@chromium.org> > Signed-off-by: Douglas Anderson <diand...@chromium.org> > --- > Changes in v6: None > Changes in v5: > - Let drivers specify DMA attrs new for v5 > > Changes in v4: None > Changes in v3: None > Changes in v2: None > > drivers/media/v4l2-core/videobuf2-dma-contig.c | 33 > +++++++++++++++++--------- > include/media/videobuf2-dma-contig.h | 11 ++++++++- > 2 files changed, 32 insertions(+), 12 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c > b/drivers/media/v4l2-core/videobuf2-dma-contig.c > index c33127284cfe..5361197f3e57 100644 > --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c > +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c > @@ -23,13 +23,16 @@ > > struct vb2_dc_conf { > struct device *dev; > + struct dma_attrs attrs; > }; > > struct vb2_dc_buf { > struct device *dev; > void *vaddr; > unsigned long size; > + void *cookie; > dma_addr_t dma_addr; > + struct dma_attrs attrs; > enum dma_data_direction dma_dir; > struct sg_table *dma_sgt; > struct frame_vector *vec; > @@ -131,7 +134,8 @@ static void vb2_dc_put(void *buf_priv) > sg_free_table(buf->sgt_base); > kfree(buf->sgt_base); > } > - dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr); > + dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, > + &buf->attrs); > put_device(buf->dev); > kfree(buf); > } > @@ -147,14 +151,18 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned > long size, > if (!buf) > return ERR_PTR(-ENOMEM); > > - buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, > - GFP_KERNEL | gfp_flags); > - if (!buf->vaddr) { > + buf->attrs = conf->attrs; > + buf->cookie = dma_alloc_attrs(dev, size, &buf->dma_addr, > + GFP_KERNEL | gfp_flags, &buf->attrs); > + if (!buf->cookie) { > dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size); > kfree(buf); > return ERR_PTR(-ENOMEM); > } > > + if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, &buf->attrs)) > + buf->vaddr = buf->cookie; > + > /* Prevent the device from being released while the buffer is used */ > buf->dev = get_device(dev); > buf->size = size; > @@ -185,8 +193,8 @@ static int vb2_dc_mmap(void *buf_priv, struct > vm_area_struct *vma) > */ > vma->vm_pgoff = 0; > > - ret = dma_mmap_coherent(buf->dev, vma, buf->vaddr, > - buf->dma_addr, buf->size); > + ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, > + buf->dma_addr, buf->size, &buf->attrs); > > if (ret) { > pr_err("Remapping memory failed, error: %d\n", ret); > @@ -329,7 +337,7 @@ static void *vb2_dc_dmabuf_ops_kmap(struct dma_buf *dbuf, > unsigned long pgnum) > { > struct vb2_dc_buf *buf = dbuf->priv; > > - return buf->vaddr + pgnum * PAGE_SIZE; > + return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL; > } > > static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf) > @@ -368,8 +376,8 @@ static struct sg_table *vb2_dc_get_base_sgt(struct > vb2_dc_buf *buf) > return NULL; > } > > - ret = dma_get_sgtable(buf->dev, sgt, buf->vaddr, buf->dma_addr, > - buf->size); > + ret = dma_get_sgtable_attrs(buf->dev, sgt, buf->cookie, buf->dma_addr, > + buf->size, &buf->attrs); > if (ret < 0) { > dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); > kfree(sgt); > @@ -721,7 +729,8 @@ const struct vb2_mem_ops vb2_dma_contig_memops = { > }; > EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); > > -void *vb2_dma_contig_init_ctx(struct device *dev) > +void *vb2_dma_contig_init_ctx_attrs(struct device *dev, > + struct dma_attrs *attrs) > { > struct vb2_dc_conf *conf; > > @@ -730,10 +739,12 @@ void *vb2_dma_contig_init_ctx(struct device *dev) > return ERR_PTR(-ENOMEM); > > conf->dev = dev; > + if (attrs) > + conf->attrs = *attrs; > > return conf; > } > -EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx); > +EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx_attrs); > > void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) > { > diff --git a/include/media/videobuf2-dma-contig.h > b/include/media/videobuf2-dma-contig.h > index c33dfa69d7ab..2087c9a68be3 100644 > --- a/include/media/videobuf2-dma-contig.h > +++ b/include/media/videobuf2-dma-contig.h > @@ -16,6 +16,8 @@ > #include <media/videobuf2-v4l2.h> > #include <linux/dma-mapping.h> > > +struct dma_attrs; > + > static inline dma_addr_t > vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, unsigned int plane_no) > { > @@ -24,7 +26,14 @@ vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, > unsigned int plane_no) > return *addr; > } > > -void *vb2_dma_contig_init_ctx(struct device *dev); > +void *vb2_dma_contig_init_ctx_attrs(struct device *dev, > + struct dma_attrs *attrs); > + > +static inline void *vb2_dma_contig_init_ctx(struct device *dev) > +{ > + return vb2_dma_contig_init_ctx_attrs(dev, NULL); > +} > + > void vb2_dma_contig_cleanup_ctx(void *alloc_ctx); > > extern const struct vb2_mem_ops vb2_dma_contig_memops; >
