| Message ID | 1312964617-3192-1-git-send-email-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > 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 <andrzej.p@samsung.com> > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > CC: Pawel Osciak <pawel@osciak.com> > --- > 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; > }
Hello, On Friday, August 12, 2011 11:55 PM Laurent Pinchart wrote: > On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > > > 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 ? DMA-mapping code for ARM platform use for_each_sg() macro which has no problems with chained SG lists. (snipped) Best regards
Hi Marek, On Tuesday 16 August 2011 07:35:05 Marek Szyprowski wrote: > On Friday, August 12, 2011 11:55 PM Laurent Pinchart wrote: > > On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > > > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > > > > > 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 ? > > DMA-mapping code for ARM platform use for_each_sg() macro which has no > problems with chained SG lists. for_each_sg() is fine, but sg_alloc_table() doesn't seem to be. __sg_alloc_table(), called from sg_alloc_table(), starts with #ifndef ARCH_HAS_SG_CHAIN BUG_ON(nents > max_ents); #endif It also calls sg_chain() internally, which starts with #ifndef ARCH_HAS_SG_CHAIN BUG(); #endif ARCH_HAS_SG_CHAIN is defined on ARM if CONFIG_ARM_HAS_SG_CHAIN is set. That's a boolean Kconfig option that is currently never set.
Hello, On Tuesday, August 16, 2011 10:42 AM Laurent Pinchart wrote: > On Tuesday 16 August 2011 07:35:05 Marek Szyprowski wrote: > > On Friday, August 12, 2011 11:55 PM Laurent Pinchart wrote: > > > On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > > > > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > > > > > > > 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 ? > > > > DMA-mapping code for ARM platform use for_each_sg() macro which has no > > problems with chained SG lists. > > for_each_sg() is fine, but sg_alloc_table() doesn't seem to be. > __sg_alloc_table(), called from sg_alloc_table(), starts with > > #ifndef ARCH_HAS_SG_CHAIN > BUG_ON(nents > max_ents); > #endif > > It also calls sg_chain() internally, which starts with > > #ifndef ARCH_HAS_SG_CHAIN > BUG(); > #endif > > ARCH_HAS_SG_CHAIN is defined on ARM if CONFIG_ARM_HAS_SG_CHAIN is set. That's > a boolean Kconfig option that is currently never set. Right, I wasn't aware of that, but it still doesn't look like an issue. The only client of dma-sg allocator is marvell-ccic, which is used on x86 systems. If one needs dma-sg allocator on ARM, he should follow the suggestion from the 74facffeca3795ffb5cf8898f5859fbb822e4c5d commit message. Best regards
Hi Marek, On Tuesday 16 August 2011 12:34:56 Marek Szyprowski wrote: > On Tuesday, August 16, 2011 10:42 AM Laurent Pinchart wrote: > > On Tuesday 16 August 2011 07:35:05 Marek Szyprowski wrote: > > > On Friday, August 12, 2011 11:55 PM Laurent Pinchart wrote: > > > > On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > > > > > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > > > > > > > > > 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 ? > > > > > > DMA-mapping code for ARM platform use for_each_sg() macro which has no > > > problems with chained SG lists. > > > > for_each_sg() is fine, but sg_alloc_table() doesn't seem to be. > > __sg_alloc_table(), called from sg_alloc_table(), starts with > > > > #ifndef ARCH_HAS_SG_CHAIN > > > > BUG_ON(nents > max_ents); > > > > #endif > > > > It also calls sg_chain() internally, which starts with > > > > #ifndef ARCH_HAS_SG_CHAIN > > > > BUG(); > > > > #endif > > > > ARCH_HAS_SG_CHAIN is defined on ARM if CONFIG_ARM_HAS_SG_CHAIN is set. > > That's a boolean Kconfig option that is currently never set. > > Right, I wasn't aware of that, but it still doesn't look like an issue. The > only client of dma-sg allocator is marvell-ccic, which is used on x86 > systems. If one needs dma-sg allocator on ARM, he should follow the > suggestion from the 74facffeca3795ffb5cf8898f5859fbb822e4c5d commit message. Won't the dma-sg allocator be the right one for systems with an IOMMU ? If so we'll soon run into this issue. I'd like to port the OMAP3 ISP driver to videobuf2.
Hello, On Tuesday, August 16, 2011 1:02 PM Laurent Pinchart wrote: > On Tuesday 16 August 2011 12:34:56 Marek Szyprowski wrote: > > On Tuesday, August 16, 2011 10:42 AM Laurent Pinchart wrote: > > > On Tuesday 16 August 2011 07:35:05 Marek Szyprowski wrote: > > > > On Friday, August 12, 2011 11:55 PM Laurent Pinchart wrote: > > > > > On Wednesday 10 August 2011 10:23:37 Marek Szyprowski wrote: > > > > > > From: Andrzej Pietrasiewicz <andrzej.p@samsung.com> > > > > > > > > > > > > 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 ? > > > > > > > > DMA-mapping code for ARM platform use for_each_sg() macro which has no > > > > problems with chained SG lists. > > > > > > for_each_sg() is fine, but sg_alloc_table() doesn't seem to be. > > > __sg_alloc_table(), called from sg_alloc_table(), starts with > > > > > > #ifndef ARCH_HAS_SG_CHAIN > > > > > > BUG_ON(nents > max_ents); > > > > > > #endif > > > > > > It also calls sg_chain() internally, which starts with > > > > > > #ifndef ARCH_HAS_SG_CHAIN > > > > > > BUG(); > > > > > > #endif > > > > > > ARCH_HAS_SG_CHAIN is defined on ARM if CONFIG_ARM_HAS_SG_CHAIN is set. > > > That's a boolean Kconfig option that is currently never set. > > > > Right, I wasn't aware of that, but it still doesn't look like an issue. The > > only client of dma-sg allocator is marvell-ccic, which is used on x86 > > systems. If one needs dma-sg allocator on ARM, he should follow the > > suggestion from the 74facffeca3795ffb5cf8898f5859fbb822e4c5d commit message. > > Won't the dma-sg allocator be the right one for systems with an IOMMU ? If so > we'll soon run into this issue. I'd like to port the OMAP3 ISP driver to > videobuf2. Nope. The correct place for IOMMU is dma-contig allocator. In theory DMA-mapping functions SHOULD hide the presence of the IOMMU from the driver. The driver would only need to get the 'dma_address' of the buffer and write it to the respective multimedia device register. The proof-of-concept of such solution for kernel allocated buffer has been presented in my first ARM dma-mapping patches: http://git.infradead.org/users/kmpark/linux-2.6-samsung/shortlog/refs/heads/dma- mapping User pointer buffers will need a bit more work to get them working correctly for both iommu and non-iommu cases. For IOMMU dma_map_sg() will just fill the scatter list with just one dma_addr entry and it will contain the address of the buffer in driver's io address space. Non-IOMMU needs some more tweaking (also in the DMA-mapping) IMHO the best way to porting OMAP3 ISP to videobuf2 is to first create a custom memory allocator that working with OMAP3 IOMMU directly and then adapt/merge/port it to DMA-mapping based approach. You can also refer to our first approaches with videobuf2-dma-iommu allocator: http://lwn.net/Articles/439175/ Especially the discussion in that thread is really important for understanding how the IOMMU should be integrated in the Linux kernel. Best regards
On Tue, 16 Aug 2011 12:34:56 +0200 Marek Szyprowski <m.szyprowski@samsung.com> wrote: > Right, I wasn't aware of that, but it still doesn't look like an issue. The only > > client of dma-sg allocator is marvell-ccic, which is used on x86 systems. If one > needs dma-sg allocator on ARM, he should follow the suggestion from the > 74facffeca3795ffb5cf8898f5859fbb822e4c5d commit message. Um...that driver runs on ARM, actually - the controller is part of the ARMADA 610 SoC... For the OLPC 1.75 there will never be a scatterlist longer than one page, I don't think. That controller can do HD, though, so longer lists are possible in the future. jon -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, On Wednesday, August 17, 2011 2:03 AM Jonathan Corbet wrote: > On Tue, 16 Aug 2011 12:34:56 +0200 > Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > > Right, I wasn't aware of that, but it still doesn't look like an issue. The only > > > > client of dma-sg allocator is marvell-ccic, which is used on x86 systems. If one > > needs dma-sg allocator on ARM, he should follow the suggestion from the > > 74facffeca3795ffb5cf8898f5859fbb822e4c5d commit message. > > Um...that driver runs on ARM, actually - the controller is part of the > ARMADA 610 SoC... Ups, I'm really sorry, it looks that I mixed something. I thought that OLPCs are only x86 based. > For the OLPC 1.75 there will never be a scatterlist longer than one > page, I don't think. That controller can do HD, though, so longer > lists are possible in the future. Ok, I see. Do you think it would be possible to ask PXA/MMP platform developers to review all the drivers that can be used on that platform and enable scatter-list chaining for this arm sub-arch? If this is a problem then we will have to delay this sg chaining patch. Best regards
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; }