From de27891f675ed1e46e8821d2e05e036e5f97586b Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 9 Sep 2021 13:24:30 +0200 Subject: [PATCH] media: videobuf2: handle non-contiguous DMA allocations This adds support for the 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 Acked-by: Christoph Hellwig Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- .../common/videobuf2/videobuf2-dma-contig.c | 161 ++++++++++++++---- 1 file changed, 130 insertions(+), 31 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index 1e218bc440c6..b052a4e36961 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -42,6 +43,7 @@ struct vb2_dc_buf { struct dma_buf_attachment *db_attach; struct vb2_buffer *vb; + bool non_coherent_mem; }; /*********************************************/ @@ -75,17 +77,39 @@ static void *vb2_dc_cookie(struct vb2_buffer *vb, void *buf_priv) return &buf->dma_addr; } +/* + * This function may fail if: + * + * - dma_buf_vmap() fails + * E.g. due to lack of virtual mapping address space, or due to + * dmabuf->ops misconfiguration. + * + * - dma_vmap_noncontiguous() fails + * For instance, when requested buffer size is larger than totalram_pages(). + * Relevant for buffers that use non-coherent memory. + * + * - Queue DMA attrs have DMA_ATTR_NO_KERNEL_MAPPING set + * Relevant for buffers that use coherent memory. + */ 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->non_coherent_mem) + buf->vaddr = dma_vmap_noncontiguous(buf->dev, buf->size, + buf->dma_sgt); return buf->vaddr; } @@ -101,13 +125,19 @@ 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; - if (!sgt) + if (!buf->non_coherent_mem) 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->vaddr) + flush_kernel_vmap_range(buf->vaddr, buf->size); } static void vb2_dc_finish(void *buf_priv) @@ -115,13 +145,19 @@ 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; - if (!sgt) + if (!buf->non_coherent_mem) 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->vaddr) + invalidate_kernel_vmap_range(buf->vaddr, buf->size); } /*********************************************/ @@ -135,21 +171,69 @@ static void vb2_dc_put(void *buf_priv) if (!refcount_dec_and_test(&buf->refcount)) return; - if (buf->sgt_base) { - sg_free_table(buf->sgt_base); - kfree(buf->sgt_base); + if (buf->non_coherent_mem) { + if (buf->vaddr) + dma_vunmap_noncontiguous(buf->dev, buf->vaddr); + dma_free_noncontiguous(buf->dev, buf->size, + buf->dma_sgt, buf->dma_dir); + } else { + if (buf->sgt_base) { + sg_free_table(buf->sgt_base); + kfree(buf->sgt_base); + } + dma_free_attrs(buf->dev, buf->size, buf->cookie, + buf->dma_addr, buf->attrs); } - dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, - buf->attrs); 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; + + buf->dma_addr = sg_dma_address(buf->dma_sgt->sgl); + + /* + * For non-coherent buffers the kernel mapping is created on demand + * in vb2_dc_vaddr(). + */ + 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 +243,28 @@ 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); + buf->dma_dir = vb->vb2_queue->dma_dir; + buf->vb = vb; + buf->non_coherent_mem = vb->vb2_queue->non_coherent_mem; + + buf->size = size; + /* Prevent the device from being released while the buffer is used */ + buf->dev = get_device(dev); + + if (buf->non_coherent_mem) + ret = vb2_dc_alloc_non_coherent(buf); + else + ret = vb2_dc_alloc_coherent(buf); + + if (ret) { + dev_err(dev, "dma alloc 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; - - /* 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; - 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 +281,12 @@ 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->non_coherent_mem) + ret = dma_mmap_noncontiguous(buf->dev, vma, buf->size, + buf->dma_sgt); + else + 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); return ret; @@ -360,9 +448,15 @@ vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf, static int vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map) { - struct vb2_dc_buf *buf = dbuf->priv; + struct vb2_dc_buf *buf; + void *vaddr; - dma_buf_map_set_vaddr(map, buf->vaddr); + buf = dbuf->priv; + vaddr = vb2_dc_vaddr(buf->vb, buf); + if (!vaddr) + return -EINVAL; + + dma_buf_map_set_vaddr(map, vaddr); return 0; } @@ -390,6 +484,9 @@ static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) int ret; struct sg_table *sgt; + if (buf->non_coherent_mem) + return buf->dma_sgt; + sgt = kmalloc(sizeof(*sgt), GFP_KERNEL); if (!sgt) { dev_err(buf->dev, "failed to alloc sg table\n"); @@ -567,6 +664,8 @@ static void *vb2_dc_get_userptr(struct vb2_buffer *vb, struct device *dev, buf->dma_addr = sg_dma_address(sgt->sgl); buf->dma_sgt = sgt; + buf->non_coherent_mem = 1; + out: buf->size = size;