[media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector (fb639eb3) · Commits · 戴 / test

drivers/media/v4l2-core/videobuf2-dma-contig.c

+34 −178

Original line number	Diff line number	Diff line
		@@ -32,15 +32,13 @@ struct vb2_dc_buf {
		dma_addr_t dma_addr;
		enum dma_data_direction dma_dir;
		struct sg_table *dma_sgt;
		struct frame_vector *vec;

		/* MMAP related */
		struct vb2_vmarea_handler handler;
		atomic_t refcount;
		struct sg_table *sgt_base;

		/* USERPTR related */
		struct vm_area_struct *vma;

		/* DMABUF related */
		struct dma_buf_attachment *db_attach;
		};
		@@ -49,24 +47,6 @@ struct vb2_dc_buf {
		/* scatterlist table functions */
		/*********************************************/


		static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
		void (cb)(struct page pg))
		{
		struct scatterlist *s;
		unsigned int i;

		for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
		struct page *page = sg_page(s);
		unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
		>> PAGE_SHIFT;
		unsigned int j;

		for (j = 0; j < n_pages; ++j, ++page)
		cb(page);
		}
		}

		static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
		{
		struct scatterlist *s;
		@@ -429,92 +409,12 @@ static struct dma_buf vb2_dc_get_dmabuf(void buf_priv, unsigned long flags)
		/* callbacks for USERPTR buffers */
		/*********************************************/

		static inline int vma_is_io(struct vm_area_struct *vma)
		{
		return !!(vma->vm_flags & (VM_IO \| VM_PFNMAP));
		}

		static int vb2_dc_get_user_pfn(unsigned long start, int n_pages,
		struct vm_area_struct vma, unsigned long res)
		{
		unsigned long pfn, start_pfn, prev_pfn;
		unsigned int i;
		int ret;

		if (!vma_is_io(vma))
		return -EFAULT;

		ret = follow_pfn(vma, start, &pfn);
		if (ret)
		return ret;

		start_pfn = pfn;
		start += PAGE_SIZE;

		for (i = 1; i < n_pages; ++i, start += PAGE_SIZE) {
		prev_pfn = pfn;
		ret = follow_pfn(vma, start, &pfn);

		if (ret) {
		pr_err("no page for address %lu\n", start);
		return ret;
		}
		if (pfn != prev_pfn + 1)
		return -EINVAL;
		}

		*res = start_pfn;
		return 0;
		}

		static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
		int n_pages, struct vm_area_struct *vma,
		enum dma_data_direction dma_dir)
		{
		if (vma_is_io(vma)) {
		unsigned int i;

		for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
		unsigned long pfn;
		int ret = follow_pfn(vma, start, &pfn);

		if (!pfn_valid(pfn))
		return -EINVAL;

		if (ret) {
		pr_err("no page for address %lu\n", start);
		return ret;
		}
		pages[i] = pfn_to_page(pfn);
		}
		} else {
		int n;

		n = get_user_pages(current, current->mm, start & PAGE_MASK,
		n_pages, dma_dir == DMA_FROM_DEVICE, 1, pages, NULL);
		/* negative error means that no page was pinned */
		n = max(n, 0);
		if (n != n_pages) {
		pr_err("got only %d of %d user pages\n", n, n_pages);
		while (n)
		put_page(pages[--n]);
		return -EFAULT;
		}
		}

		return 0;
		}

		static void vb2_dc_put_dirty_page(struct page *page)
		{
		set_page_dirty_lock(page);
		put_page(page);
		}

		static void vb2_dc_put_userptr(void *buf_priv)
		{
		struct vb2_dc_buf *buf = buf_priv;
		struct sg_table *sgt = buf->dma_sgt;
		int i;
		struct page **pages;

		if (sgt) {
		DEFINE_DMA_ATTRS(attrs);
		@@ -526,13 +426,15 @@ static void vb2_dc_put_userptr(void *buf_priv)
		*/
		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
		buf->dma_dir, &attrs);
		if (!vma_is_io(buf->vma))
		vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);

		pages = frame_vector_pages(buf->vec);
		/* sgt should exist only if vector contains pages... */
		BUG_ON(IS_ERR(pages));
		for (i = 0; i < frame_vector_count(buf->vec); i++)
		set_page_dirty_lock(pages[i]);
		sg_free_table(sgt);
		kfree(sgt);
		}
		vb2_put_vma(buf->vma);
		vb2_destroy_framevec(buf->vec);
		kfree(buf);
		}

		@@ -572,13 +474,10 @@ static void vb2_dc_get_userptr(void alloc_ctx, unsigned long vaddr,
		{
		struct vb2_dc_conf *conf = alloc_ctx;
		struct vb2_dc_buf *buf;
		unsigned long start;
		unsigned long end;
		struct frame_vector *vec;
		unsigned long offset;
		struct page **pages;
		int n_pages;
		int n_pages, i;
		int ret = 0;
		struct vm_area_struct *vma;
		struct sg_table *sgt;
		unsigned long contig_size;
		unsigned long dma_align = dma_get_cache_alignment();
		@@ -604,75 +503,43 @@ static void vb2_dc_get_userptr(void alloc_ctx, unsigned long vaddr,
		buf->dev = conf->dev;
		buf->dma_dir = dma_dir;

		start = vaddr & PAGE_MASK;
		offset = vaddr & ~PAGE_MASK;
		end = PAGE_ALIGN(vaddr + size);
		n_pages = (end - start) >> PAGE_SHIFT;

		pages = kmalloc(n_pages * sizeof(pages[0]), GFP_KERNEL);
		if (!pages) {
		ret = -ENOMEM;
		pr_err("failed to allocate pages table\n");
		vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
		if (IS_ERR(vec)) {
		ret = PTR_ERR(vec);
		goto fail_buf;
		}
		buf->vec = vec;
		n_pages = frame_vector_count(vec);
		ret = frame_vector_to_pages(vec);
		if (ret < 0) {
		unsigned long *nums = frame_vector_pfns(vec);

		down_read(&current->mm->mmap_sem);
		/* current->mm->mmap_sem is taken by videobuf2 core */
		vma = find_vma(current->mm, vaddr);
		if (!vma) {
		pr_err("no vma for address %lu\n", vaddr);
		ret = -EFAULT;
		goto fail_pages;
		}

		if (vma->vm_end < vaddr + size) {
		pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size);
		ret = -EFAULT;
		goto fail_pages;
		}

		buf->vma = vb2_get_vma(vma);
		if (!buf->vma) {
		pr_err("failed to copy vma\n");
		ret = -ENOMEM;
		goto fail_pages;
		}

		/* extract page list from userspace mapping */
		ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, dma_dir);
		if (ret) {
		unsigned long pfn;
		if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) {
		up_read(&current->mm->mmap_sem);
		buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, pfn);
		buf->size = size;
		kfree(pages);
		return buf;
		}

		pr_err("failed to get user pages\n");
		goto fail_vma;
		/*
		* Failed to convert to pages... Check the memory is physically
		* contiguous and use direct mapping
		*/
		for (i = 1; i < n_pages; i++)
		if (nums[i-1] + 1 != nums[i])
		goto fail_pfnvec;
		buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]);
		goto out;
		}
		up_read(&current->mm->mmap_sem);

		sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
		if (!sgt) {
		pr_err("failed to allocate sg table\n");
		ret = -ENOMEM;
		goto fail_get_user_pages;
		goto fail_pfnvec;
		}

		ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
		ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages,
		offset, size, GFP_KERNEL);
		if (ret) {
		pr_err("failed to initialize sg table\n");
		goto fail_sgt;
		}

		/* pages are no longer needed */
		kfree(pages);
		pages = NULL;

		/*
		* No need to sync to the device, this will happen later when the
		* prepare() memop is called.
		@@ -694,8 +561,9 @@ static void vb2_dc_get_userptr(void alloc_ctx, unsigned long vaddr,
		}

		buf->dma_addr = sg_dma_address(sgt->sgl);
		buf->size = size;
		buf->dma_sgt = sgt;
		out:
		buf->size = size;

		return buf;

		@@ -704,25 +572,13 @@ fail_map_sg:
		buf->dma_dir, &attrs);

		fail_sgt_init:
		if (!vma_is_io(buf->vma))
		vb2_dc_sgt_foreach_page(sgt, put_page);
		sg_free_table(sgt);

		fail_sgt:
		kfree(sgt);

		fail_get_user_pages:
		if (pages && !vma_is_io(buf->vma))
		while (n_pages)
		put_page(pages[--n_pages]);

		down_read(&current->mm->mmap_sem);
		fail_vma:
		vb2_put_vma(buf->vma);

		fail_pages:
		up_read(&current->mm->mmap_sem);
		kfree(pages); /* kfree is NULL-proof */
		fail_pfnvec:
		vb2_destroy_framevec(vec);

		fail_buf:
		kfree(buf);

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