[media] vb2-dma-sg: move dma_(un)map_sg here

This moves dma_(un)map_sg to the get_userptr/put_userptr and alloc/put
memops of videobuf2-dma-sg.c and adds dma_sync_sg_for_device/cpu to the
prepare/finish memops.

Now that vb2-dma-sg will sync the buffers for you in the prepare/finish
memops we can drop that from the drivers that use dma-sg.

For the solo6x10 driver that was a bit more involved because it needs to
copy JPEG or MPEG headers to the buffer before returning it to userspace,
and that cannot be done in the old place since the buffer there is still
setup for DMA access, not for CPU access. However, the buf_finish
op is the ideal place to do this. By the time buf_finish is called
the buffer is available for CPU access, so copying to the buffer is fine.

[mchehab@osg.samsung.com: Fix a compilation breakage:
 drivers/media/v4l2-core/videobuf2-dma-sg.c:150:19: error: 'struct vb2_dma_sg_buf' has no member named 'dma_sgt']

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 2bf13dc4df34..346e39b2aae8 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -96,6 +96,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
 {
         struct vb2_dma_sg_conf *conf = alloc_ctx;
         struct vb2_dma_sg_buf *buf;
+        struct sg_table *sgt;
         int ret;
         int num_pages;
 
@@ -128,6 +129,12 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
 
         /* Prevent the device from being released while the buffer is used */
         buf->dev = get_device(conf->dev);
+
+        sgt = &buf->sg_table;
+        if (dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir) == 0)
+                goto fail_map;
+        dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+
         buf->handler.refcount = &buf->refcount;
         buf->handler.put = vb2_dma_sg_put;
         buf->handler.arg = buf;
@@ -138,6 +145,9 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
                 __func__, buf->num_pages);
         return buf;
 
+fail_map:
+        put_device(buf->dev);
+        sg_free_table(sgt);
 fail_table_alloc:
         num_pages = buf->num_pages;
         while (num_pages--)
@@ -152,11 +162,13 @@ fail_pages_array_alloc:
 static void vb2_dma_sg_put(void *buf_priv)
 {
         struct vb2_dma_sg_buf *buf = buf_priv;
+        struct sg_table *sgt = &buf->sg_table;
         int i = buf->num_pages;
 
         if (atomic_dec_and_test(&buf->refcount)) {
                 dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
                         buf->num_pages);
+                dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
                 if (buf->vaddr)
                         vm_unmap_ram(buf->vaddr, buf->num_pages);
                 sg_free_table(&buf->sg_table);
@@ -168,6 +180,22 @@ static void vb2_dma_sg_put(void *buf_priv)
         }
 }
 
+static void vb2_dma_sg_prepare(void *buf_priv)
+{
+        struct vb2_dma_sg_buf *buf = buf_priv;
+        struct sg_table *sgt = &buf->sg_table;
+
+        dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
+static void vb2_dma_sg_finish(void *buf_priv)
+{
+        struct vb2_dma_sg_buf *buf = buf_priv;
+        struct sg_table *sgt = &buf->sg_table;
+
+        dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
 static inline int vma_is_io(struct vm_area_struct *vma)
 {
         return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
@@ -177,16 +205,19 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
                                     unsigned long size,
                                     enum dma_data_direction dma_dir)
 {
+        struct vb2_dma_sg_conf *conf = alloc_ctx;
         struct vb2_dma_sg_buf *buf;
         unsigned long first, last;
         int num_pages_from_user;
         struct vm_area_struct *vma;
+        struct sg_table *sgt;
 
         buf = kzalloc(sizeof *buf, GFP_KERNEL);
         if (!buf)
                 return NULL;
 
         buf->vaddr = NULL;
+        buf->dev = conf->dev;
         buf->dma_dir = dma_dir;
         buf->offset = vaddr & ~PAGE_MASK;
         buf->size = size;
@@ -246,8 +277,14 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
                         buf->num_pages, buf->offset, size, 0))
                 goto userptr_fail_alloc_table_from_pages;
 
+        sgt = &buf->sg_table;
+        if (dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir) == 0)
+                goto userptr_fail_map;
+        dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
         return buf;
 
+userptr_fail_map:
+        sg_free_table(&buf->sg_table);
 userptr_fail_alloc_table_from_pages:
 userptr_fail_get_user_pages:
         dprintk(1, "get_user_pages requested/got: %d/%d]\n",
@@ -270,10 +307,12 @@ userptr_fail_alloc_pages:
 static void vb2_dma_sg_put_userptr(void *buf_priv)
 {
         struct vb2_dma_sg_buf *buf = buf_priv;
+        struct sg_table *sgt = &buf->sg_table;
         int i = buf->num_pages;
 
         dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
                __func__, buf->num_pages);
+        dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
         if (buf->vaddr)
                 vm_unmap_ram(buf->vaddr, buf->num_pages);
         sg_free_table(&buf->sg_table);
@@ -360,6 +399,8 @@ const struct vb2_mem_ops vb2_dma_sg_memops = {
         .put            = vb2_dma_sg_put,
         .get_userptr    = vb2_dma_sg_get_userptr,
         .put_userptr    = vb2_dma_sg_put_userptr,
+        .prepare        = vb2_dma_sg_prepare,
+        .finish         = vb2_dma_sg_finish,
         .vaddr          = vb2_dma_sg_vaddr,
         .mmap           = vb2_dma_sg_mmap,
         .num_users      = vb2_dma_sg_num_users,