Hi, On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > From: Andrzej Pietrasiewicz <[email protected]> > > Scatter-gather lib provides a helper functions to allocate scatter list, > so there is no need to use vmalloc for it. sg_alloc_table() splits > allocation into page size chunks and links them together into a chain.
Last time I check ARM platforms didn't support SG list chaining. Has that been fixed ? > Signed-off-by: Andrzej Pietrasiewicz <[email protected]> > Signed-off-by: Kyungmin Park <[email protected]> > Signed-off-by: Marek Szyprowski <[email protected]> > CC: Pawel Osciak <[email protected]> > --- > drivers/media/video/videobuf2-dma-sg.c | 54 > +++++++++++++++++++------------ 1 files changed, 33 insertions(+), 21 > deletions(-) > > diff --git a/drivers/media/video/videobuf2-dma-sg.c > b/drivers/media/video/videobuf2-dma-sg.c index 065f468..e1158f9 100644 > --- a/drivers/media/video/videobuf2-dma-sg.c > +++ b/drivers/media/video/videobuf2-dma-sg.c > @@ -36,6 +36,8 @@ static void vb2_dma_sg_put(void *buf_priv); > static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size) > { > struct vb2_dma_sg_buf *buf; > + struct sg_table sgt; > + struct scatterlist *sl; > int i; > > buf = kzalloc(sizeof *buf, GFP_KERNEL); > @@ -48,23 +50,21 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned > long size) buf->sg_desc.size = size; > buf->sg_desc.num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; > > - buf->sg_desc.sglist = vzalloc(buf->sg_desc.num_pages * > - sizeof(*buf->sg_desc.sglist)); > - if (!buf->sg_desc.sglist) > + if (sg_alloc_table(&sgt, buf->sg_desc.num_pages, GFP_KERNEL)) > goto fail_sglist_alloc; > - sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages); > + buf->sg_desc.sglist = sgt.sgl; > > buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *), > GFP_KERNEL); > if (!buf->pages) > goto fail_pages_array_alloc; > > - for (i = 0; i < buf->sg_desc.num_pages; ++i) { > - buf->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO | > __GFP_NOWARN); > + for_each_sg(buf->sg_desc.sglist, sl, buf->sg_desc.num_pages, i) { > + buf->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO | > + __GFP_NOWARN); > if (NULL == buf->pages[i]) > goto fail_pages_alloc; > - sg_set_page(&buf->sg_desc.sglist[i], > - buf->pages[i], PAGE_SIZE, 0); > + sg_set_page(sl, buf->pages[i], PAGE_SIZE, 0); > } > > buf->handler.refcount = &buf->refcount; > @@ -89,7 +89,7 @@ fail_pages_alloc: > kfree(buf->pages); > > fail_pages_array_alloc: > - vfree(buf->sg_desc.sglist); > + sg_free_table(&sgt); > > fail_sglist_alloc: > kfree(buf); > @@ -99,6 +99,7 @@ fail_sglist_alloc: > static void vb2_dma_sg_put(void *buf_priv) > { > struct vb2_dma_sg_buf *buf = buf_priv; > + struct sg_table sgt; > int i = buf->sg_desc.num_pages; > > if (atomic_dec_and_test(&buf->refcount)) { > @@ -106,7 +107,9 @@ static void vb2_dma_sg_put(void *buf_priv) > buf->sg_desc.num_pages); > if (buf->vaddr) > vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages); > - vfree(buf->sg_desc.sglist); > + sgt.sgl = buf->sg_desc.sglist; > + sgt.orig_nents = sgt.nents = i; > + sg_free_table(&sgt); > while (--i >= 0) > __free_page(buf->pages[i]); > kfree(buf->pages); > @@ -118,6 +121,8 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, > unsigned long vaddr, unsigned long size, int write) > { > struct vb2_dma_sg_buf *buf; > + struct sg_table sgt; > + struct scatterlist *sl; > unsigned long first, last; > int num_pages_from_user, i; > > @@ -134,12 +139,9 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, > unsigned long vaddr, last = ((vaddr + size - 1) & PAGE_MASK) >> > PAGE_SHIFT; > buf->sg_desc.num_pages = last - first + 1; > > - buf->sg_desc.sglist = vzalloc( > - buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist)); > - if (!buf->sg_desc.sglist) > + if (sg_alloc_table(&sgt, buf->sg_desc.num_pages, GFP_KERNEL)) > goto userptr_fail_sglist_alloc; > - > - sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages); > + buf->sg_desc.sglist = sgt.sgl; > > buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *), > GFP_KERNEL); > @@ -158,12 +160,12 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, > unsigned long vaddr, if (num_pages_from_user != buf->sg_desc.num_pages) > goto userptr_fail_get_user_pages; > > - sg_set_page(&buf->sg_desc.sglist[0], buf->pages[0], > - PAGE_SIZE - buf->offset, buf->offset); > + sl = buf->sg_desc.sglist; > + sg_set_page(sl, buf->pages[0], PAGE_SIZE - buf->offset, buf->offset); > size -= PAGE_SIZE - buf->offset; > for (i = 1; i < buf->sg_desc.num_pages; ++i) { > - sg_set_page(&buf->sg_desc.sglist[i], buf->pages[i], > - min_t(size_t, PAGE_SIZE, size), 0); > + sl = sg_next(sl); > + sg_set_page(sl, buf->pages[i], min_t(size_t, PAGE_SIZE, size), > 0); > size -= min_t(size_t, PAGE_SIZE, size); > } > return buf; > @@ -176,7 +178,7 @@ userptr_fail_get_user_pages: > kfree(buf->pages); > > userptr_fail_pages_array_alloc: > - vfree(buf->sg_desc.sglist); > + sg_free_table(&sgt); > > userptr_fail_sglist_alloc: > kfree(buf); > @@ -190,6 +192,8 @@ userptr_fail_sglist_alloc: > static void vb2_dma_sg_put_userptr(void *buf_priv) > { > struct vb2_dma_sg_buf *buf = buf_priv; > + struct sg_table sgt; > + > int i = buf->sg_desc.num_pages; > > printk(KERN_DEBUG "%s: Releasing userspace buffer of %d pages\n", > @@ -201,7 +205,9 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) > set_page_dirty_lock(buf->pages[i]); > put_page(buf->pages[i]); > } > - vfree(buf->sg_desc.sglist); > + sgt.sgl = buf->sg_desc.sglist; > + sgt.orig_nents = sgt.nents = buf->sg_desc.num_pages; > + sg_free_table(&sgt); > kfree(buf->pages); > kfree(buf); > } > @@ -218,6 +224,12 @@ static void *vb2_dma_sg_vaddr(void *buf_priv) > -1, > PAGE_KERNEL); > > + if (!buf->vaddr) { > + printk(KERN_ERR "Cannot map buffer memory " > + "into kernel address space\n"); > + return NULL; > + } > + > /* add offset in case userptr is not page-aligned */ > return buf->vaddr + buf->offset; > } -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
