This patch removes a workaround for extraction of struct pages from DMA buffer. The method of using follow_pfn for artificial VMA is dropped in favour of dma_get_sgtable function.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/videobuf2-dma-contig.c | 60 ++-------------------------- 1 file changed, 4 insertions(+), 56 deletions(-)
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index a845ff7..73297b7 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -361,73 +361,21 @@ static struct dma_buf_ops vb2_dc_dmabuf_ops = { .release = vb2_dc_dmabuf_ops_release, };
-/** - * vb2_dc_kaddr_to_pages() - extract list of struct pages from a kernel - * pointer. This function is a workaround to extract pages from a pointer - * returned by dma_alloc_coherent. The pages are obtained by creating an - * artificial vma and using follow_pfn to do a page walk to find a PFN - */ -static int vb2_dc_kaddr_to_pages(unsigned long kaddr, - struct page **pages, unsigned int n_pages) -{ - unsigned int i; - unsigned long pfn; - /* create an artificial VMA */ - struct vm_area_struct vma = { - .vm_flags = VM_IO | VM_PFNMAP, - .vm_mm = &init_mm, - }; - - for (i = 0; i < n_pages; ++i, kaddr += PAGE_SIZE) { - if (follow_pfn(&vma, kaddr, &pfn)) - break; - pages[i] = pfn_to_page(pfn); - } - - return i; -} - static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) { - int n_pages; - struct page **pages = NULL; int ret; struct sg_table *sgt;
- n_pages = PAGE_ALIGN(buf->size) >> PAGE_SHIFT; - - pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL); - if (!pages) { - dev_err(buf->dev, "failed to alloc page table\n"); - return ERR_PTR(-ENOMEM); - } - - ret = vb2_dc_kaddr_to_pages((unsigned long)buf->vaddr, pages, n_pages); - if (ret < 0) { - dev_err(buf->dev, "failed to get buffer pages from DMA API\n"); - kfree(pages); - return ERR_PTR(ret); - } - if (ret != n_pages) { - dev_err(buf->dev, "got only %d of %d pages from DMA API\n", - ret, n_pages); - kfree(pages); - return ERR_PTR(-EFAULT); - } - sgt = kmalloc(sizeof *sgt, GFP_KERNEL); if (!sgt) { dev_err(buf->dev, "failed to alloc sg table\n"); - kfree(pages); return ERR_PTR(-ENOMEM); }
- ret = sg_alloc_table_from_pages(sgt, pages, n_pages, 0, - buf->size, GFP_KERNEL); - /* failure or not, pages are no longer needed */ - kfree(pages); - if (ret) { - dev_err(buf->dev, "failed to covert pages to sg table\n"); + ret = dma_get_sgtable(buf->dev, sgt, buf->vaddr, buf->dma_addr, + buf->size, NULL); + if (ret < 0) { + dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); kfree(sgt); return ERR_PTR(ret); }