Message ID | 20210709092027.1050834-9-senozhatsky@chromium.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | videobuf2: support new noncontiguous DMA API | expand |
Hi On 09.07.21 11:20, Sergey Senozhatsky wrote: > This adds support for new noncontiguous DMA API, which > requires allocators to have two execution branches: one > for the current API, and one for the new one. > > Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> > Acked-by: Christoph Hellwig <hch@lst.de> > --- > .../common/videobuf2/videobuf2-dma-contig.c | 139 ++++++++++++++---- > 1 file changed, 114 insertions(+), 25 deletions(-) > > diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c > index 1e218bc440c6..7408ac9ed60a 100644 > --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c > +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c > @@ -17,6 +17,7 @@ > #include <linux/sched.h> > #include <linux/slab.h> > #include <linux/dma-mapping.h> > +#include <linux/highmem.h> > > #include <media/videobuf2-v4l2.h> > #include <media/videobuf2-dma-contig.h> > @@ -42,6 +43,7 @@ struct vb2_dc_buf { > struct dma_buf_attachment *db_attach; > > struct vb2_buffer *vb; > + bool coherent_mem; > }; > > /*********************************************/ > @@ -78,14 +80,22 @@ static void *vb2_dc_cookie(struct vb2_buffer *vb, void *buf_priv) > static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv) > { > struct vb2_dc_buf *buf = buf_priv; > - struct dma_buf_map map; > - int ret; > > - if (!buf->vaddr && buf->db_attach) { > - ret = dma_buf_vmap(buf->db_attach->dmabuf, &map); > - buf->vaddr = ret ? NULL : map.vaddr; > + 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; > } > > @@ -101,13 +111,26 @@ static void vb2_dc_prepare(void *buf_priv) > struct vb2_dc_buf *buf = buf_priv; > struct sg_table *sgt = buf->dma_sgt; > > + /* This takes care of DMABUF and user-enforced cache sync hint */ > if (buf->vb->skip_cache_sync_on_prepare) > return; > > + /* > + * Coherent MMAP buffers do not need to be synced, unlike USERPTR > + * and non-coherent MMAP buffers. > + */ > + if (buf->vb->memory == V4L2_MEMORY_MMAP && buf->coherent_mem) > + return; > + > if (!sgt) > return; > > + /* For both USERPTR and non-coherent MMAP */ > dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); > + > + /* Non-coherent MMAP only */ > + if (!buf->coherent_mem && buf->vaddr) > + flush_kernel_vmap_range(buf->vaddr, buf->size); > } > > static void vb2_dc_finish(void *buf_priv) > @@ -115,13 +138,26 @@ static void vb2_dc_finish(void *buf_priv) > struct vb2_dc_buf *buf = buf_priv; > struct sg_table *sgt = buf->dma_sgt; > > + /* This takes care of DMABUF and user-enforced cache sync hint */ > if (buf->vb->skip_cache_sync_on_finish) > return; > > + /* > + * Coherent MMAP buffers do not need to be synced, unlike USERPTR > + * and non-coherent MMAP buffers. > + */ > + if (buf->vb->memory == V4L2_MEMORY_MMAP && buf->coherent_mem) > + return; > + > if (!sgt) > return; > > + /* For both USERPTR and non-coherent MMAP */ > dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); > + > + /* Non-coherent MMAP only */ > + if (!buf->coherent_mem && buf->vaddr) > + invalidate_kernel_vmap_range(buf->vaddr, buf->size); > } > > /*********************************************/ > @@ -139,17 +175,63 @@ static void vb2_dc_put(void *buf_priv) > sg_free_table(buf->sgt_base); > kfree(buf->sgt_base); > } > - dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, > - buf->attrs); > + > + if (buf->coherent_mem) { > + dma_free_attrs(buf->dev, buf->size, buf->cookie, > + buf->dma_addr, buf->attrs); > + } else { > + if (buf->vaddr) > + dma_vunmap_noncontiguous(buf->dev, buf->vaddr); > + dma_free_noncontiguous(buf->dev, buf->size, > + buf->dma_sgt, buf->dma_addr); The last argument for dma_free_noncontiguous should be dma_dir. Also, the 'cookie' cb returns buf->dma_addr which is not initialized for the noncontiguous api. So it is not clear how drivers should use the new api. Many drivers call vb2_dma_contig_plane_dma_addr which returns the cookie. Thanks, Dafna > + } > put_device(buf->dev); > kfree(buf); > } > > +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; > + /* > + * For requests that need kernel mapping (DMA_ATTR_NO_KERNEL_MAPPING > + * bit is cleared) we perform dma_vmap_noncontiguous() in vb2_dc_vadd(). > + */ > + return 0; > +} > + > static void *vb2_dc_alloc(struct vb2_buffer *vb, > struct device *dev, > unsigned long size) > { > struct vb2_dc_buf *buf; > + int ret; > > if (WARN_ON(!dev)) > return ERR_PTR(-EINVAL); > @@ -159,27 +241,28 @@ static void *vb2_dc_alloc(struct vb2_buffer *vb, > return ERR_PTR(-ENOMEM); > > buf->attrs = vb->vb2_queue->dma_attrs; > - buf->cookie = dma_alloc_attrs(dev, size, &buf->dma_addr, > - GFP_KERNEL | vb->vb2_queue->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 ((buf->attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0) > - buf->vaddr = buf->cookie; > + buf->dma_dir = vb->vb2_queue->dma_dir; > + buf->vb = vb; > + buf->coherent_mem = vb->vb2_queue->coherent_mem; > > + buf->size = size; > /* Prevent the device from being released while the buffer is used */ > buf->dev = get_device(dev); > - buf->size = size; > - buf->dma_dir = vb->vb2_queue->dma_dir; > + > + if (buf->coherent_mem) > + ret = vb2_dc_alloc_coherent(buf); > + else > + ret = vb2_dc_alloc_non_coherent(buf); > + > + if (ret) { > + dev_err(dev, "dma alloc of size %ld failed\n", size); > + kfree(buf); > + return ERR_PTR(-ENOMEM); > + } > > buf->handler.refcount = &buf->refcount; > buf->handler.put = vb2_dc_put; > buf->handler.arg = buf; > - buf->vb = vb; > > refcount_set(&buf->refcount, 1); > > @@ -196,9 +279,12 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) > return -EINVAL; > } > > - ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, > - buf->dma_addr, buf->size, buf->attrs); > - > + if (buf->coherent_mem) > + ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, buf->dma_addr, > + buf->size, buf->attrs); > + else > + ret = dma_mmap_noncontiguous(buf->dev, vma, buf->size, > + buf->dma_sgt); > if (ret) { > pr_err("Remapping memory failed, error: %d\n", ret); > return ret; > @@ -362,7 +448,7 @@ static int vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map) > { > struct vb2_dc_buf *buf = dbuf->priv; > > - dma_buf_map_set_vaddr(map, buf->vaddr); > + dma_buf_map_set_vaddr(map, vb2_dc_vaddr(buf->vb, buf)); > > return 0; > } > @@ -390,6 +476,9 @@ static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) > int ret; > struct sg_table *sgt; > > + if (!buf->coherent_mem) > + return buf->dma_sgt; > + > sgt = kmalloc(sizeof(*sgt), GFP_KERNEL); > if (!sgt) { > dev_err(buf->dev, "failed to alloc sg table\n"); >
On (21/07/22 19:26), Dafna Hirschfeld wrote: > Also, the 'cookie' cb returns buf->dma_addr which is not initialized for > the noncontiguous api. So it is not clear how drivers should use the new api. > Many drivers call vb2_dma_contig_plane_dma_addr which returns the cookie. Hmm, that's a good find. Is ->dma_addr the same as what we have in sgt.sgl->dma_address for non-contig?
On Mon, Jul 26, 2021 at 12:59 PM Sergey Senozhatsky <senozhatsky@chromium.org> wrote: > > On (21/07/22 19:26), Dafna Hirschfeld wrote: > > Also, the 'cookie' cb returns buf->dma_addr which is not initialized for > > the noncontiguous api. So it is not clear how drivers should use the new api. > > Many drivers call vb2_dma_contig_plane_dma_addr which returns the cookie. > > Hmm, that's a good find. Is ->dma_addr the same as what we have in > sgt.sgl->dma_address for non-contig? Yes. As per [1]: "The return sg_table is guaranteed to have 1 single DMA mapped segment as indicated by sgt->nents, but it might have multiple CPU side segments as indicated by sgt->orig_nents." [1] https://www.kernel.org/doc/html/latest/core-api/dma-api.html#part-ii-non-coherent-dma-allocations
On (21/07/26 13:04), Tomasz Figa wrote: > On Mon, Jul 26, 2021 at 12:59 PM Sergey Senozhatsky > <senozhatsky@chromium.org> wrote: > > > > On (21/07/22 19:26), Dafna Hirschfeld wrote: > > > Also, the 'cookie' cb returns buf->dma_addr which is not initialized for > > > the noncontiguous api. So it is not clear how drivers should use the new api. > > > Many drivers call vb2_dma_contig_plane_dma_addr which returns the cookie. > > > > Hmm, that's a good find. Is ->dma_addr the same as what we have in > > sgt.sgl->dma_address for non-contig? > > Yes. As per [1]: > > "The return sg_table is guaranteed to have 1 single DMA mapped segment > as indicated by sgt->nents, but it might have multiple CPU side > segments as indicated by sgt->orig_nents." Thanks. So the fix can look as follows: --- 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; + buf->dma_addr = sg_dma_address(buf->dma_sgt->sgl); ---
On (21/07/22 19:26), Dafna Hirschfeld wrote: > > /*********************************************/ > > @@ -139,17 +175,63 @@ static void vb2_dc_put(void *buf_priv) > > sg_free_table(buf->sgt_base); > > kfree(buf->sgt_base); > > } > > - dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, > > - buf->attrs); > > + > > + if (buf->coherent_mem) { > > + dma_free_attrs(buf->dev, buf->size, buf->cookie, > > + buf->dma_addr, buf->attrs); > > + } else { > > + if (buf->vaddr) > > + dma_vunmap_noncontiguous(buf->dev, buf->vaddr); > > + dma_free_noncontiguous(buf->dev, buf->size, > > + buf->dma_sgt, buf->dma_addr); > > The last argument for dma_free_noncontiguous should be dma_dir. > Also, the 'cookie' cb returns buf->dma_addr which is not initialized for > the noncontiguous api. So it is not clear how drivers should use the new api. Done. Thank you Dafna.
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index 1e218bc440c6..7408ac9ed60a 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -17,6 +17,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/dma-mapping.h> +#include <linux/highmem.h> #include <media/videobuf2-v4l2.h> #include <media/videobuf2-dma-contig.h> @@ -42,6 +43,7 @@ struct vb2_dc_buf { struct dma_buf_attachment *db_attach; struct vb2_buffer *vb; + bool coherent_mem; }; /*********************************************/ @@ -78,14 +80,22 @@ static void *vb2_dc_cookie(struct vb2_buffer *vb, void *buf_priv) static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv) { struct vb2_dc_buf *buf = buf_priv; - struct dma_buf_map map; - int ret; - if (!buf->vaddr && buf->db_attach) { - ret = dma_buf_vmap(buf->db_attach->dmabuf, &map); - buf->vaddr = ret ? NULL : map.vaddr; + 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; } @@ -101,13 +111,26 @@ static void vb2_dc_prepare(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; + /* This takes care of DMABUF and user-enforced cache sync hint */ if (buf->vb->skip_cache_sync_on_prepare) return; + /* + * Coherent MMAP buffers do not need to be synced, unlike USERPTR + * and non-coherent MMAP buffers. + */ + if (buf->vb->memory == V4L2_MEMORY_MMAP && buf->coherent_mem) + return; + if (!sgt) return; + /* For both USERPTR and non-coherent MMAP */ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); + + /* Non-coherent MMAP only */ + if (!buf->coherent_mem && buf->vaddr) + flush_kernel_vmap_range(buf->vaddr, buf->size); } static void vb2_dc_finish(void *buf_priv) @@ -115,13 +138,26 @@ static void vb2_dc_finish(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; + /* This takes care of DMABUF and user-enforced cache sync hint */ if (buf->vb->skip_cache_sync_on_finish) return; + /* + * Coherent MMAP buffers do not need to be synced, unlike USERPTR + * and non-coherent MMAP buffers. + */ + if (buf->vb->memory == V4L2_MEMORY_MMAP && buf->coherent_mem) + return; + if (!sgt) return; + /* For both USERPTR and non-coherent MMAP */ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); + + /* Non-coherent MMAP only */ + if (!buf->coherent_mem && buf->vaddr) + invalidate_kernel_vmap_range(buf->vaddr, buf->size); } /*********************************************/ @@ -139,17 +175,63 @@ static void vb2_dc_put(void *buf_priv) sg_free_table(buf->sgt_base); kfree(buf->sgt_base); } - dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, - buf->attrs); + + if (buf->coherent_mem) { + dma_free_attrs(buf->dev, buf->size, buf->cookie, + buf->dma_addr, buf->attrs); + } else { + if (buf->vaddr) + dma_vunmap_noncontiguous(buf->dev, buf->vaddr); + dma_free_noncontiguous(buf->dev, buf->size, + buf->dma_sgt, buf->dma_addr); + } put_device(buf->dev); kfree(buf); } +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; + /* + * For requests that need kernel mapping (DMA_ATTR_NO_KERNEL_MAPPING + * bit is cleared) we perform dma_vmap_noncontiguous() in vb2_dc_vadd(). + */ + return 0; +} + static void *vb2_dc_alloc(struct vb2_buffer *vb, struct device *dev, unsigned long size) { struct vb2_dc_buf *buf; + int ret; if (WARN_ON(!dev)) return ERR_PTR(-EINVAL); @@ -159,27 +241,28 @@ static void *vb2_dc_alloc(struct vb2_buffer *vb, return ERR_PTR(-ENOMEM); buf->attrs = vb->vb2_queue->dma_attrs; - buf->cookie = dma_alloc_attrs(dev, size, &buf->dma_addr, - GFP_KERNEL | vb->vb2_queue->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 ((buf->attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0) - buf->vaddr = buf->cookie; + buf->dma_dir = vb->vb2_queue->dma_dir; + buf->vb = vb; + buf->coherent_mem = vb->vb2_queue->coherent_mem; + buf->size = size; /* Prevent the device from being released while the buffer is used */ buf->dev = get_device(dev); - buf->size = size; - buf->dma_dir = vb->vb2_queue->dma_dir; + + if (buf->coherent_mem) + ret = vb2_dc_alloc_coherent(buf); + else + ret = vb2_dc_alloc_non_coherent(buf); + + if (ret) { + dev_err(dev, "dma alloc of size %ld failed\n", size); + kfree(buf); + return ERR_PTR(-ENOMEM); + } buf->handler.refcount = &buf->refcount; buf->handler.put = vb2_dc_put; buf->handler.arg = buf; - buf->vb = vb; refcount_set(&buf->refcount, 1); @@ -196,9 +279,12 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) return -EINVAL; } - ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, - buf->dma_addr, buf->size, buf->attrs); - + if (buf->coherent_mem) + ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, buf->dma_addr, + buf->size, buf->attrs); + else + ret = dma_mmap_noncontiguous(buf->dev, vma, buf->size, + buf->dma_sgt); if (ret) { pr_err("Remapping memory failed, error: %d\n", ret); return ret; @@ -362,7 +448,7 @@ static int vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map) { struct vb2_dc_buf *buf = dbuf->priv; - dma_buf_map_set_vaddr(map, buf->vaddr); + dma_buf_map_set_vaddr(map, vb2_dc_vaddr(buf->vb, buf)); return 0; } @@ -390,6 +476,9 @@ static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) int ret; struct sg_table *sgt; + if (!buf->coherent_mem) + return buf->dma_sgt; + sgt = kmalloc(sizeof(*sgt), GFP_KERNEL); if (!sgt) { dev_err(buf->dev, "failed to alloc sg table\n");