| Message ID | 1385470724-20632-1-git-send-email-ricardo.ribalda@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello, On 2013-11-26 13:58, Ricardo Ribalda Delgado wrote: > 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 <ricardo.ribalda@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/media/v4l2-core/videobuf2-dma-sg.c | 54 +++++++++++++++++++++++++++--- > 1 file changed, 49 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c > index 2f86054..104e4b9 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) > @@ -178,9 +185,40 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, > buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), > GFP_KERNEL); > if (!buf->pages) > - return NULL; > + goto userptr_fail_alloc_pages; > + > + 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; > > - num_pages_from_user = get_user_pages(current, current->mm, > + 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, > @@ -201,9 +239,13 @@ userptr_fail_alloc_table_from_pages: > userptr_fail_get_user_pages: > dprintk(1, "get_user_pages requested/got: %d/%d]\n", > num_pages_from_user, buf->num_pages); > - 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); > +userptr_fail_alloc_pages: > kfree(buf); > return NULL; > } > @@ -225,9 +267,11 @@ 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); > } > Best regards
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index 2f86054..104e4b9 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) @@ -178,9 +185,40 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), GFP_KERNEL); if (!buf->pages) - return NULL; + goto userptr_fail_alloc_pages; + + 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; - num_pages_from_user = get_user_pages(current, current->mm, + 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, @@ -201,9 +239,13 @@ userptr_fail_alloc_table_from_pages: userptr_fail_get_user_pages: dprintk(1, "get_user_pages requested/got: %d/%d]\n", num_pages_from_user, buf->num_pages); - 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); +userptr_fail_alloc_pages: kfree(buf); return NULL; } @@ -225,9 +267,11 @@ 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); }
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 <ricardo.ribalda@gmail.com> --- drivers/media/v4l2-core/videobuf2-dma-sg.c | 54 +++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 5 deletions(-)