1 files changed, 148 insertions, 72 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 25c3b360e1a..adefc31bb85 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -21,22 +21,76 @@
 #include <media/videobuf2-memops.h>
 #include <media/videobuf2-dma-sg.h>
 
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...)					\
+	do {								\
+		if (debug >= level)					\
+			printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg);	\
+	} while (0)
+
 struct vb2_dma_sg_buf {
 	void				*vaddr;
 	struct page			**pages;
 	int				write;
 	int				offset;
-	struct vb2_dma_sg_desc		sg_desc;
+	struct sg_table			sg_table;
+	size_t				size;
+	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);
 
-static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
+static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
+		gfp_t gfp_flags)
+{
+	unsigned int last_page = 0;
+	int size = buf->size;
+
+	while (size > 0) {
+		struct page *pages;
+		int order;
+		int i;
+
+		order = get_order(size);
+		/* Dont over allocate*/
+		if ((PAGE_SIZE << order) > size)
+			order--;
+
+		pages = NULL;
+		while (!pages) {
+			pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
+					__GFP_NOWARN | gfp_flags, order);
+			if (pages)
+				break;
+
+			if (order == 0) {
+				while (last_page--)
+					__free_page(buf->pages[last_page]);
+				return -ENOMEM;
+			}
+			order--;
+		}
+
+		split_page(pages, order);
+		for (i = 0; i < (1 << order); i++)
+			buf->pages[last_page++] = &pages[i];
+
+		size -= PAGE_SIZE << order;
+	}
+
+	return 0;
+}
+
+static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
 {
 	struct vb2_dma_sg_buf *buf;
-	int i;
+	int ret;
+	int num_pages;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
@@ -45,27 +99,23 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
 	buf->vaddr = NULL;
 	buf->write = 0;
 	buf->offset = 0;
-	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)
-		goto fail_sglist_alloc;
-	sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+	buf->size = size;
+	/* size is already page aligned */
+	buf->num_pages = size >> PAGE_SHIFT;
 
-	buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+	buf->pages = kzalloc(buf->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);
-		if (NULL == buf->pages[i])
-			goto fail_pages_alloc;
-		sg_set_page(&buf->sg_desc.sglist[i],
-			    buf->pages[i], PAGE_SIZE, 0);
-	}
+	ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
+	if (ret)
+		goto fail_pages_alloc;
+
+	ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+			buf->num_pages, 0, size, gfp_flags);
+	if (ret)
+		goto fail_table_alloc;
 
 	buf->handler.refcount = &buf->refcount;
 	buf->handler.put = vb2_dma_sg_put;
@@ -73,19 +123,17 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
 
 	atomic_inc(&buf->refcount);
 
-	printk(KERN_DEBUG "%s: Allocated buffer of %d pages\n",
-		__func__, buf->sg_desc.num_pages);
+	dprintk(1, "%s: Allocated buffer of %d pages\n",
+		__func__, buf->num_pages);
 	return buf;
 
+fail_table_alloc:
+	num_pages = buf->num_pages;
+	while (num_pages--)
+		__free_page(buf->pages[num_pages]);
 fail_pages_alloc:
-	while (--i >= 0)
-		__free_page(buf->pages[i]);
 	kfree(buf->pages);
-
 fail_pages_array_alloc:
-	vfree(buf->sg_desc.sglist);
-
-fail_sglist_alloc:
 	kfree(buf);
 	return NULL;
 }
@@ -93,14 +141,14 @@ fail_sglist_alloc:
 static void vb2_dma_sg_put(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	int i = buf->sg_desc.num_pages;
+	int i = buf->num_pages;
 
 	if (atomic_dec_and_test(&buf->refcount)) {
-		printk(KERN_DEBUG "%s: Freeing buffer of %d pages\n", __func__,
-			buf->sg_desc.num_pages);
+		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
+			buf->num_pages);
 		if (buf->vaddr)
-			vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
-		vfree(buf->sg_desc.sglist);
+			vm_unmap_ram(buf->vaddr, buf->num_pages);
+		sg_free_table(&buf->sg_table);
 		while (--i >= 0)
 			__free_page(buf->pages[i]);
 		kfree(buf->pages);
@@ -108,12 +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, i;
+	int num_pages_from_user;
+	struct vm_area_struct *vma;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
@@ -122,56 +176,76 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->vaddr = NULL;
 	buf->write = write;
 	buf->offset = vaddr & ~PAGE_MASK;
-	buf->sg_desc.size = size;
+	buf->size = size;
 
 	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
 	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)
-		goto userptr_fail_sglist_alloc;
+	buf->num_pages = last - first + 1;
 
-	sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
-
-	buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
 			     GFP_KERNEL);
 	if (!buf->pages)
-		goto userptr_fail_pages_array_alloc;
+		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;
+	}
 
-	num_pages_from_user = get_user_pages(current, current->mm,
+	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(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->sg_desc.num_pages,
+					     buf->num_pages,
 					     write,
 					     1, /* force */
 					     buf->pages,
 					     NULL);
 
-	if (num_pages_from_user != buf->sg_desc.num_pages)
+	if (num_pages_from_user != buf->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);
-	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);
-		size -= min_t(size_t, PAGE_SIZE, size);
-	}
+	if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+			buf->num_pages, buf->offset, size, 0))
+		goto userptr_fail_alloc_table_from_pages;
+
 	return buf;
 
+userptr_fail_alloc_table_from_pages:
 userptr_fail_get_user_pages:
-	printk(KERN_DEBUG "get_user_pages requested/got: %d/%d]\n",
-	       num_pages_from_user, buf->sg_desc.num_pages);
-	while (--num_pages_from_user >= 0)
-		put_page(buf->pages[num_pages_from_user]);
+	dprintk(1, "get_user_pages requested/got: %d/%d]\n",
+		buf->num_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_pages_array_alloc:
-	vfree(buf->sg_desc.sglist);
-
-userptr_fail_sglist_alloc:
+userptr_fail_alloc_pages:
 	kfree(buf);
 	return NULL;
 }
@@ -183,19 +257,21 @@ userptr_fail_sglist_alloc:
 static void vb2_dma_sg_put_userptr(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	int i = buf->sg_desc.num_pages;
+	int i = buf->num_pages;
 
-	printk(KERN_DEBUG "%s: Releasing userspace buffer of %d pages\n",
-	       __func__, buf->sg_desc.num_pages);
+	dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
+	       __func__, buf->num_pages);
 	if (buf->vaddr)
-		vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
+		vm_unmap_ram(buf->vaddr, buf->num_pages);
+	sg_free_table(&buf->sg_table);
 	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]);
 	}
-	vfree(buf->sg_desc.sglist);
 	kfree(buf->pages);
+	vb2_put_vma(buf->vma);
 	kfree(buf);
 }
 
@@ -207,7 +283,7 @@ static void *vb2_dma_sg_vaddr(void *buf_priv)
 
 	if (!buf->vaddr)
 		buf->vaddr = vm_map_ram(buf->pages,
-					buf->sg_desc.num_pages,
+					buf->num_pages,
 					-1,
 					PAGE_KERNEL);
 
@@ -263,7 +339,7 @@ static void *vb2_dma_sg_cookie(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
 
-	return &buf->sg_desc;
+	return &buf->sg_table;
 }
 
 const struct vb2_mem_ops vb2_dma_sg_memops = {