[media] videobuf2-dma-sg: Replace vb2_dma_sg_desc with sg_table

Replace the private struct vb2_dma_sg_desc with the struct sg_table so
we can benefit from all the helping functions in lib/scatterlist.c for
things like allocating the sg or compacting the descriptor.
marvel-ccic and solo6x10 drivers, that use this API have been updated.

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
[s.nawrocki@samsung.com: minor corrections of the changelog]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

4 files changed, 63 insertions, 84 deletions

diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 5184887b155c..32fab30a9105 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1221,16 +1221,16 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 {
         struct mcam_vb_buffer *mvb = vb_to_mvb(vb);
         struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
-        struct vb2_dma_sg_desc *sgd = vb2_dma_sg_plane_desc(vb, 0);
+        struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
         struct mcam_dma_desc *desc = mvb->dma_desc;
         struct scatterlist *sg;
         int i;
 
-        mvb->dma_desc_nent = dma_map_sg(cam->dev, sgd->sglist, sgd->num_pages,
-                        DMA_FROM_DEVICE);
+        mvb->dma_desc_nent = dma_map_sg(cam->dev, sg_table->sgl,
+                        sg_table->nents, DMA_FROM_DEVICE);
         if (mvb->dma_desc_nent <= 0)
                 return -EIO;  /* Not sure what's right here */
-        for_each_sg(sgd->sglist, sg, mvb->dma_desc_nent, i) {
+        for_each_sg(sg_table->sgl, sg, mvb->dma_desc_nent, i) {
                 desc->dma_addr = sg_dma_address(sg);
                 desc->segment_len = sg_dma_len(sg);
                 desc++;
@@ -1241,9 +1241,11 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 static int mcam_vb_sg_buf_finish(struct vb2_buffer *vb)
 {
         struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
-        struct vb2_dma_sg_desc *sgd = vb2_dma_sg_plane_desc(vb, 0);
+        struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
 
-        dma_unmap_sg(cam->dev, sgd->sglist, sgd->num_pages, DMA_FROM_DEVICE);
+        if (sg_table)
+                dma_unmap_sg(cam->dev, sg_table->sgl,
+                                sg_table->nents, DMA_FROM_DEVICE);
         return 0;
 }
 
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 4999c4886898..2f860543912c 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -35,7 +35,9 @@ struct vb2_dma_sg_buf {
         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;
 };
@@ -46,7 +48,7 @@ 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->sg_desc.size;
+        int size = buf->size;
 
         while (size > 0) {
                 struct page *pages;
@@ -74,12 +76,8 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
                 }
 
                 split_page(pages, order);
-                for (i = 0; i < (1 << order); i++) {
-                        buf->pages[last_page] = &pages[i];
-                        sg_set_page(&buf->sg_desc.sglist[last_page],
-                                        buf->pages[last_page], PAGE_SIZE, 0);
-                        last_page++;
-                }
+                for (i = 0; i < (1 << order); i++)
+                        buf->pages[last_page++] = &pages[i];
 
                 size -= PAGE_SIZE << order;
         }
@@ -91,6 +89,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 {
         struct vb2_dma_sg_buf *buf;
         int ret;
+        int num_pages;
 
         buf = kzalloc(sizeof *buf, GFP_KERNEL);
         if (!buf)
@@ -99,17 +98,11 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
         buf->vaddr = NULL;
         buf->write = 0;
         buf->offset = 0;
-        buf->sg_desc.size = size;
+        buf->size = size;
         /* size is already page aligned */
-        buf->sg_desc.num_pages = size >> 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->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;
@@ -118,6 +111,11 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
         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;
         buf->handler.arg = buf;
@@ -125,16 +123,16 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
         atomic_inc(&buf->refcount);
 
         dprintk(1, "%s: Allocated buffer of %d pages\n",
-                __func__, buf->sg_desc.num_pages);
+                __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:
         kfree(buf->pages);
-
 fail_pages_array_alloc:
-        vfree(buf->sg_desc.sglist);
-
-fail_sglist_alloc:
         kfree(buf);
         return NULL;
 }
@@ -142,14 +140,14 @@ 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)) {
                 dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
-                        buf->sg_desc.num_pages);
+                        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);
@@ -162,7 +160,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 {
         struct vb2_dma_sg_buf *buf;
         unsigned long first, last;
-        int num_pages_from_user, i;
+        int num_pages_from_user;
 
         buf = kzalloc(sizeof *buf, GFP_KERNEL);
         if (!buf)
@@ -171,56 +169,41 @@ 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;
+                return NULL;
 
         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:
         dprintk(1, "get_user_pages requested/got: %d/%d]\n",
-               num_pages_from_user, buf->sg_desc.num_pages);
+               num_pages_from_user, buf->num_pages);
         while (--num_pages_from_user >= 0)
                 put_page(buf->pages[num_pages_from_user]);
         kfree(buf->pages);
-
-userptr_fail_pages_array_alloc:
-        vfree(buf->sg_desc.sglist);
-
-userptr_fail_sglist_alloc:
         kfree(buf);
         return NULL;
 }
@@ -232,18 +215,18 @@ 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;
 
         dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
-               __func__, buf->sg_desc.num_pages);
+               __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]);
         }
-        vfree(buf->sg_desc.sglist);
         kfree(buf->pages);
         kfree(buf);
 }
@@ -256,7 +239,7 @@ 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);
 
@@ -312,7 +295,7 @@ 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 = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index a4c589604b02..9a6d5c0b1339 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -346,7 +346,7 @@ static int enc_get_mpeg_dma(struct solo_dev *solo_dev, dma_addr_t dma,
 /* Build a descriptor queue out of an SG list and send it to the P2M for
  * processing. */
 static int solo_send_desc(struct solo_enc_dev *solo_enc, int skip,
-                          struct vb2_dma_sg_desc *vbuf, int off, int size,
+                          struct sg_table *vbuf, int off, int size,
                           unsigned int base, unsigned int base_size)
 {
         struct solo_dev *solo_dev = solo_enc->solo_dev;
@@ -359,7 +359,7 @@ static int solo_send_desc(struct solo_enc_dev *solo_enc, int skip,
 
         solo_enc->desc_count = 1;
 
-        for_each_sg(vbuf->sglist, sg, vbuf->num_pages, i) {
+        for_each_sg(vbuf->sgl, sg, vbuf->nents, i) {
                 struct solo_p2m_desc *desc;
                 dma_addr_t dma;
                 int len;
@@ -434,7 +434,7 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
                 struct vb2_buffer *vb, struct vop_header *vh)
 {
         struct solo_dev *solo_dev = solo_enc->solo_dev;
-        struct vb2_dma_sg_desc *vbuf = vb2_dma_sg_plane_desc(vb, 0);
+        struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
         int frame_size;
         int ret;
 
@@ -443,7 +443,7 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
         if (vb2_plane_size(vb, 0) < vh->jpeg_size + solo_enc->jpeg_len)
                 return -EIO;
 
-        sg_copy_from_buffer(vbuf->sglist, vbuf->num_pages,
+        sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
                         solo_enc->jpeg_header,
                         solo_enc->jpeg_len);
 
@@ -451,12 +451,12 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
                 & ~(DMA_ALIGN - 1);
         vb2_set_plane_payload(vb, 0, vh->jpeg_size + solo_enc->jpeg_len);
 
-        dma_map_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+        dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
                         DMA_FROM_DEVICE);
         ret = solo_send_desc(solo_enc, solo_enc->jpeg_len, vbuf, vh->jpeg_off,
                         frame_size, SOLO_JPEG_EXT_ADDR(solo_dev),
                         SOLO_JPEG_EXT_SIZE(solo_dev));
-        dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+        dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
                         DMA_FROM_DEVICE);
         return ret;
 }
@@ -465,7 +465,7 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
                 struct vb2_buffer *vb, struct vop_header *vh)
 {
         struct solo_dev *solo_dev = solo_enc->solo_dev;
-        struct vb2_dma_sg_desc *vbuf = vb2_dma_sg_plane_desc(vb, 0);
+        struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
         int frame_off, frame_size;
         int skip = 0;
         int ret;
@@ -475,7 +475,7 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 
         /* If this is a key frame, add extra header */
         if (!vh->vop_type) {
-                sg_copy_from_buffer(vbuf->sglist, vbuf->num_pages,
+                sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
                                 solo_enc->vop,
                                 solo_enc->vop_len);
 
@@ -494,12 +494,12 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
         frame_size = (vh->mpeg_size + skip + (DMA_ALIGN - 1))
                 & ~(DMA_ALIGN - 1);
 
-        dma_map_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+        dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
                         DMA_FROM_DEVICE);
         ret = solo_send_desc(solo_enc, skip, vbuf, frame_off, frame_size,
                         SOLO_MP4E_EXT_ADDR(solo_dev),
                         SOLO_MP4E_EXT_SIZE(solo_dev));
-        dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+        dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
                         DMA_FROM_DEVICE);
         return ret;
 }
diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
index 0038526b8ef7..7b89852779af 100644
--- a/include/media/videobuf2-dma-sg.h
+++ b/include/media/videobuf2-dma-sg.h
@@ -15,16 +15,10 @@
 
 #include <media/videobuf2-core.h>
 
-struct vb2_dma_sg_desc {
-        unsigned long           size;
-        unsigned int            num_pages;
-        struct scatterlist      *sglist;
-};
-
-static inline struct vb2_dma_sg_desc *vb2_dma_sg_plane_desc(
+static inline struct sg_table *vb2_dma_sg_plane_desc(
                 struct vb2_buffer *vb, unsigned int plane_no)
 {
-        return (struct vb2_dma_sg_desc *)vb2_plane_cookie(vb, plane_no);
+        return (struct sg_table *)vb2_plane_cookie(vb, plane_no);
 }
 
 extern const struct vb2_mem_ops vb2_dma_sg_memops;