This adds support for new noncontiguous DMA API, which
requires allocators to have two execution branches: one
for the current API, and one for the new one.

Signed-off-by: Sergey Senozhatsky <senozhat...@chromium.org>
[hch: untested conversion to the ne API]
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 .../common/videobuf2/videobuf2-dma-contig.c   | 141 +++++++++++++++---
 1 file changed, 117 insertions(+), 24 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c 
b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index 1e218bc440c6..d6a9f7b682f3 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -17,6 +17,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
+#include <linux/highmem.h>
 
 #include <media/videobuf2-v4l2.h>
 #include <media/videobuf2-dma-contig.h>
@@ -42,8 +43,14 @@ struct vb2_dc_buf {
        struct dma_buf_attachment       *db_attach;
 
        struct vb2_buffer               *vb;
+       unsigned int                    non_coherent_mem:1;
 };
 
+static bool vb2_dc_is_coherent(struct vb2_dc_buf *buf)
+{
+       return !buf->non_coherent_mem;
+}
+
 /*********************************************/
 /*        scatterlist table functions        */
 /*********************************************/
@@ -78,12 +85,21 @@ static void *vb2_dc_cookie(struct vb2_buffer *vb, void 
*buf_priv)
 static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv)
 {
        struct vb2_dc_buf *buf = buf_priv;
-       struct dma_buf_map map;
-       int ret;
 
-       if (!buf->vaddr && buf->db_attach) {
-               ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
-               buf->vaddr = ret ? NULL : map.vaddr;
+       if (buf->vaddr)
+               return buf->vaddr;
+
+       if (buf->db_attach) {
+               struct dma_buf_map map;
+
+               if (!dma_buf_vmap(buf->db_attach->dmabuf, &map))
+                       buf->vaddr = map.vaddr;
+       }
+
+       if (!vb2_dc_is_coherent(buf)) {
+               buf->vaddr = dma_vmap_noncontiguous(buf->dev,
+                                                   buf->size,
+                                                   buf->dma_sgt);
        }
 
        return buf->vaddr;
@@ -101,13 +117,26 @@ static void vb2_dc_prepare(void *buf_priv)
        struct vb2_dc_buf *buf = buf_priv;
        struct sg_table *sgt = buf->dma_sgt;
 
+       /* This takes care of DMABUF and user-enforced cache sync hint */
        if (buf->vb->skip_cache_sync_on_prepare)
                return;
 
+       /*
+        * Coherent MMAP buffers do not need to be synced, unlike coherent
+        * USERPTR and non-coherent MMAP buffers.
+        */
+       if (buf->vb->memory == V4L2_MEMORY_MMAP && vb2_dc_is_coherent(buf))
+               return;
+
        if (!sgt)
                return;
 
+       /* For both USERPTR and non-coherent MMAP */
        dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
+
+       /* Non-coherrent MMAP only */
+       if (!vb2_dc_is_coherent(buf) && buf->vaddr)
+               flush_kernel_vmap_range(buf->vaddr, buf->size);
 }
 
 static void vb2_dc_finish(void *buf_priv)
@@ -115,19 +144,46 @@ static void vb2_dc_finish(void *buf_priv)
        struct vb2_dc_buf *buf = buf_priv;
        struct sg_table *sgt = buf->dma_sgt;
 
+       /* This takes care of DMABUF and user-enforced cache sync hint */
        if (buf->vb->skip_cache_sync_on_finish)
                return;
 
+       /*
+        * Coherent MMAP buffers do not need to be synced, unlike coherent
+        * USERPTR and non-coherent MMAP buffers.
+        */
+       if (buf->vb->memory == V4L2_MEMORY_MMAP && vb2_dc_is_coherent(buf))
+               return;
+
        if (!sgt)
                return;
 
+       /* For both USERPTR and non-coherent MMAP */
        dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
+
+       /* Non-coherrent MMAP only */
+       if (!vb2_dc_is_coherent(buf) && buf->vaddr)
+               invalidate_kernel_vmap_range(buf->vaddr, buf->size);
 }
 
 /*********************************************/
 /*        callbacks for MMAP buffers         */
 /*********************************************/
 
+static void __vb2_dc_put(struct vb2_dc_buf *buf)
+{
+       if (vb2_dc_is_coherent(buf)) {
+               dma_free_attrs(buf->dev, buf->size, buf->cookie,
+                              buf->dma_addr, buf->attrs);
+               return;
+       }
+
+       if (buf->vaddr)
+               dma_vunmap_noncontiguous(buf->dev, buf->vaddr);
+       dma_free_noncontiguous(buf->dev, buf->size,
+                              buf->dma_sgt, buf->dma_addr);
+}
+
 static void vb2_dc_put(void *buf_priv)
 {
        struct vb2_dc_buf *buf = buf_priv;
@@ -139,17 +195,47 @@ static void vb2_dc_put(void *buf_priv)
                sg_free_table(buf->sgt_base);
                kfree(buf->sgt_base);
        }
-       dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr,
-                      buf->attrs);
+       __vb2_dc_put(buf);
        put_device(buf->dev);
        kfree(buf);
 }
 
+static int vb2_dc_alloc_coherent(struct vb2_dc_buf *buf)
+{
+       struct vb2_queue *q = buf->vb->vb2_queue;
+
+       buf->cookie = dma_alloc_attrs(buf->dev,
+                                     buf->size,
+                                     &buf->dma_addr,
+                                     GFP_KERNEL | q->gfp_flags,
+                                     buf->attrs);
+       if (!buf->cookie)
+               return -ENOMEM;
+       if ((q->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0)
+               buf->vaddr = buf->cookie;
+       return 0;
+}
+
+static int vb2_dc_alloc_non_coherent(struct vb2_dc_buf *buf)
+{
+       struct vb2_queue *q = buf->vb->vb2_queue;
+
+       buf->dma_sgt = dma_alloc_noncontiguous(buf->dev,
+                                              buf->size,
+                                              buf->dma_dir,
+                                              GFP_KERNEL | q->gfp_flags,
+                                              buf->attrs);
+       if (!buf->dma_sgt)
+               return -ENOMEM;
+       return 0;
+}
+
 static void *vb2_dc_alloc(struct vb2_buffer *vb,
                          struct device *dev,
                          unsigned long size)
 {
        struct vb2_dc_buf *buf;
+       int ret;
 
        if (WARN_ON(!dev))
                return ERR_PTR(-EINVAL);
@@ -159,27 +245,28 @@ static void *vb2_dc_alloc(struct vb2_buffer *vb,
                return ERR_PTR(-ENOMEM);
 
        buf->attrs = vb->vb2_queue->dma_attrs;
-       buf->cookie = dma_alloc_attrs(dev, size, &buf->dma_addr,
-                                     GFP_KERNEL | vb->vb2_queue->gfp_flags,
-                                     buf->attrs);
-       if (!buf->cookie) {
-               dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
-               kfree(buf);
-               return ERR_PTR(-ENOMEM);
-       }
-
-       if ((buf->attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0)
-               buf->vaddr = buf->cookie;
+       buf->dma_dir = vb->vb2_queue->dma_dir;
+       buf->vb = vb;
+       buf->non_coherent_mem = vb->vb2_queue->non_coherent_mem;
 
+       buf->size = size;
        /* Prevent the device from being released while the buffer is used */
        buf->dev = get_device(dev);
-       buf->size = size;
-       buf->dma_dir = vb->vb2_queue->dma_dir;
+
+       if (vb2_dc_is_coherent(buf))
+               ret = vb2_dc_alloc_coherent(buf);
+       else
+               ret = vb2_dc_alloc_non_coherent(buf);
+
+       if (ret) {
+               dev_err(dev, "dma alloc of size %ld failed\n", size);
+               kfree(buf);
+               return ERR_PTR(-ENOMEM);
+       }
 
        buf->handler.refcount = &buf->refcount;
        buf->handler.put = vb2_dc_put;
        buf->handler.arg = buf;
-       buf->vb = vb;
 
        refcount_set(&buf->refcount, 1);
 
@@ -196,9 +283,12 @@ static int vb2_dc_mmap(void *buf_priv, struct 
vm_area_struct *vma)
                return -EINVAL;
        }
 
-       ret = dma_mmap_attrs(buf->dev, vma, buf->cookie,
-               buf->dma_addr, buf->size, buf->attrs);
-
+       if (vb2_dc_is_coherent(buf))
+               ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, buf->dma_addr,
+                                    buf->size, buf->attrs);
+       else
+               ret = dma_mmap_noncontiguous(buf->dev, vma, buf->size,
+                                            buf->dma_sgt);
        if (ret) {
                pr_err("Remapping memory failed, error: %d\n", ret);
                return ret;
@@ -390,6 +480,9 @@ static struct sg_table *vb2_dc_get_base_sgt(struct 
vb2_dc_buf *buf)
        int ret;
        struct sg_table *sgt;
 
+       if (!vb2_dc_is_coherent(buf))
+               return buf->dma_sgt;
+
        sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
        if (!sgt) {
                dev_err(buf->dev, "failed to alloc sg table\n");
-- 
2.30.1.766.gb4fecdf3b7-goog

Reply via email to