From 50ac952d2263bd5d7812acf1839d57c34c6f8d9f Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Tue, 26 Nov 2013 09:58:44 -0300 Subject: [PATCH] [media] videobuf2-dma-sg: Support io userptr operations on io memory Memory exported via remap_pfn_range cannot be remapped via get_user_pages. Other videobuf2 methods (like the dma-contig) supports io memory. This patch adds support for this kind of memory. v2: Comments by Marek Szyprowski -Use vb2_get_vma and vb2_put_vma Signed-off-by: Ricardo Ribalda Delgado Acked-by: Marek Szyprowski Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-dma-sg.c | 51 ++++++++++++++++++++-- 1 file changed, 47 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index c13bf95f9f5..d86bb8cdadd 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -40,6 +40,7 @@ struct vb2_dma_sg_buf { unsigned int num_pages; atomic_t refcount; struct vb2_vmarea_handler handler; + struct vm_area_struct *vma; }; static void vb2_dma_sg_put(void *buf_priv); @@ -155,12 +156,18 @@ static void vb2_dma_sg_put(void *buf_priv) } } +static inline int vma_is_io(struct vm_area_struct *vma) +{ + return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); +} + static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, unsigned long size, int write) { struct vb2_dma_sg_buf *buf; unsigned long first, last; int num_pages_from_user; + struct vm_area_struct *vma; buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) @@ -180,7 +187,38 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, if (!buf->pages) return NULL; - num_pages_from_user = get_user_pages(current, current->mm, + vma = find_vma(current->mm, vaddr); + if (!vma) { + dprintk(1, "no vma for address %lu\n", vaddr); + goto userptr_fail_find_vma; + } + + if (vma->vm_end < vaddr + size) { + dprintk(1, "vma at %lu is too small for %lu bytes\n", + vaddr, size); + goto userptr_fail_find_vma; + } + + buf->vma = vb2_get_vma(vma); + if (!buf->vma) { + dprintk(1, "failed to copy vma\n"); + goto userptr_fail_find_vma; + } + + if (vma_is_io(buf->vma)) { + for (num_pages_from_user = 0; + num_pages_from_user < buf->num_pages; + ++num_pages_from_user, vaddr += PAGE_SIZE) { + unsigned long pfn; + + if (follow_pfn(buf->vma, vaddr, &pfn)) { + dprintk(1, "no page for address %lu\n", vaddr); + break; + } + buf->pages[num_pages_from_user] = pfn_to_page(pfn); + } + } else + num_pages_from_user = get_user_pages(current, current->mm, vaddr & PAGE_MASK, buf->num_pages, write, @@ -201,8 +239,11 @@ userptr_fail_alloc_table_from_pages: userptr_fail_get_user_pages: dprintk(1, "get_user_pages requested/got: %d/%d]\n", buf->num_pages, num_pages_from_user); - while (--num_pages_from_user >= 0) - put_page(buf->pages[num_pages_from_user]); + if (!vma_is_io(buf->vma)) + while (--num_pages_from_user >= 0) + put_page(buf->pages[num_pages_from_user]); + vb2_put_vma(buf->vma); +userptr_fail_find_vma: kfree(buf->pages); kfree(buf); return NULL; @@ -225,9 +266,11 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) while (--i >= 0) { if (buf->write) set_page_dirty_lock(buf->pages[i]); - put_page(buf->pages[i]); + if (!vma_is_io(buf->vma)) + put_page(buf->pages[i]); } kfree(buf->pages); + vb2_put_vma(buf->vma); kfree(buf); } -- 2.41.0