The desirable DMA attributes are not generic for all devices using
Videobuf2 contiguous DMA ops. Let the drivers decide.
This change also results in MMAP buffers always having an sg_table
(dma_sgt field).
Also arrange the header files alphabetically.
As a result, also the DMA-BUF exporter must provide ops for synchronising
the cache. This adds begin_cpu_access and end_cpu_access ops to
vb2_dc_dmabuf_ops.
The driver API changes were done using the following coccinelle spatch:
@@
expression E;
@@
- vb2_dma_contig_init_ctx(E)
+ vb2_dma_contig_init_ctx(E, NULL)
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/videobuf2-dma-contig.c | 104 ++++++++++++++++++-------
include/media/videobuf2-dma-contig.h | 3 +-
2 files changed, 79 insertions(+), 28 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 65bc687..65ee122 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -11,11 +11,11 @@
*/
#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/dma-mapping.h>
#include <media/videobuf2-core.h>
#include <media/videobuf2-dma-contig.h>
@@ -23,6 +23,7 @@
struct vb2_dc_conf {
struct device *dev;
+ struct dma_attrs attrs;
};
struct vb2_dc_buf {
@@ -34,6 +35,7 @@ struct vb2_dc_buf {
struct sg_table *dma_sgt;
/* MMAP related */
+ struct dma_attrs *attrs;
struct vb2_vmarea_handler handler;
atomic_t refcount;
@@ -135,8 +137,12 @@ static void vb2_dc_prepare(void *buf_priv)
struct vb2_dc_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;
- /* DMABUF exporter will flush the cache for us */
- if (!buf->vma)
+ /*
+ * DMABUF exporter will flush the cache for us; only USERPTR
+ * and MMAP buffers with non-coherent memory will be flushed.
+ */
+ if (!buf->attrs ||
+ !dma_get_attr(DMA_ATTR_NON_CONSISTENT, buf->attrs))
return;
dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
@@ -147,8 +153,12 @@ static void vb2_dc_finish(void *buf_priv)
struct vb2_dc_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;
- /* DMABUF exporter will flush the cache for us */
- if (!buf->vma)
+ /*
+ * DMABUF exporter will flush the cache for us; only USERPTR
+ * and MMAP buffers with non-coherent memory will be flushed.
+ */
+ if (!buf->attrs ||
+ !dma_get_attr(DMA_ATTR_NON_CONSISTENT, buf->attrs))
return;
dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
@@ -169,7 +179,8 @@ static void vb2_dc_put(void *buf_priv)
sg_free_table(buf->dma_sgt);
kfree(buf->dma_sgt);
}
- dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
+ dma_free_attrs(buf->dev, buf->size, buf->vaddr, buf->dma_addr,
+ buf->attrs);
put_device(buf->dev);
kfree(buf);
}
@@ -185,14 +196,25 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size,
if (!buf)
return ERR_PTR(-ENOMEM);
- buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr,
- GFP_KERNEL | gfp_flags);
+ buf->attrs = &conf->attrs;
+
+ buf->vaddr = dma_alloc_attrs(dev, size, &buf->dma_addr,
+ GFP_KERNEL | gfp_flags, buf->attrs);
if (!buf->vaddr) {
- dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
+ dev_err(dev, "dma_alloc_attrs of size %ld failed\n", size);
kfree(buf);
return ERR_PTR(-ENOMEM);
}
+ if (dma_get_attr(DMA_ATTR_NON_CONSISTENT, buf->attrs)) {
+ buf->dma_sgt = vb2_dc_get_base_sgt(buf);
+ if (!buf->dma_sgt) {
+ dma_free_attrs(dev, size, buf->vaddr, buf->dma_addr,
+ buf->attrs);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
/* Prevent the device from being released while the buffer is used */
buf->dev = get_device(dev);
buf->size = size;
@@ -223,8 +245,8 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
*/
vma->vm_pgoff = 0;
- ret = dma_mmap_coherent(buf->dev, vma, buf->vaddr,
- buf->dma_addr, buf->size);
+ ret = dma_mmap_attrs(buf->dev, vma, buf->vaddr, buf->dma_addr,
+ buf->size, buf->attrs);
if (ret) {
pr_err("Remapping memory failed, error: %d\n", ret);
@@ -370,6 +392,34 @@ static void *vb2_dc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
return buf->vaddr + pgnum * PAGE_SIZE;
}
+static int vb2_dc_dmabuf_ops_begin_cpu_access(
+ struct dma_buf *dbuf, size_t start, size_t len,
+ enum dma_data_direction direction)
+{
+ struct vb2_dc_buf *buf = dbuf->priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, buf->attrs))
+ return 0;
+
+ dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+
+ return 0;
+}
+
+static void vb2_dc_dmabuf_ops_end_cpu_access(
+ struct dma_buf *dbuf, size_t start, size_t len,
+ enum dma_data_direction direction)
+{
+ struct vb2_dc_buf *buf = dbuf->priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, buf->attrs))
+ return;
+
+ dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf)
{
struct vb2_dc_buf *buf = dbuf->priv;
@@ -390,6 +440,8 @@ static struct dma_buf_ops vb2_dc_dmabuf_ops = {
.unmap_dma_buf = vb2_dc_dmabuf_ops_unmap,
.kmap = vb2_dc_dmabuf_ops_kmap,
.kmap_atomic = vb2_dc_dmabuf_ops_kmap,
+ .begin_cpu_access = vb2_dc_dmabuf_ops_begin_cpu_access,
+ .end_cpu_access = vb2_dc_dmabuf_ops_end_cpu_access,
.vmap = vb2_dc_dmabuf_ops_vmap,
.mmap = vb2_dc_dmabuf_ops_mmap,
.release = vb2_dc_dmabuf_ops_release,
@@ -514,15 +566,13 @@ static void vb2_dc_put_userptr(void *buf_priv)
struct sg_table *sgt = buf->dma_sgt;
if (sgt) {
- DEFINE_DMA_ATTRS(attrs);
-
- dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
/*
- * No need to sync to CPU, it's already synced to the CPU
- * since the finish() memop will have been called before this.
+ * Don't ask to skip cache sync in case if the user
+ * did ask to skip cache flush the last time the
+ * buffer was dequeued.
*/
dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, &attrs);
+ buf->dma_dir, buf->attrs);
if (!vma_is_io(buf->vma))
vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
@@ -579,9 +629,6 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
struct sg_table *sgt;
unsigned long contig_size;
unsigned long dma_align = dma_get_cache_alignment();
- DEFINE_DMA_ATTRS(attrs);
-
- dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
/* Only cache aligned DMA transfers are reliable */
if (!IS_ALIGNED(vaddr | size, dma_align)) {
@@ -598,6 +645,8 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
if (!buf)
return ERR_PTR(-ENOMEM);
+ buf->attrs = &conf->attrs;
+
buf->dev = conf->dev;
buf->dma_dir = dma_dir;
@@ -667,12 +716,8 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
kfree(pages);
pages = NULL;
- /*
- * No need to sync to the device, this will happen later when the
- * prepare() memop is called.
- */
sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, &attrs);
+ buf->dma_dir, buf->attrs);
if (sgt->nents <= 0) {
pr_err("failed to map scatterlist\n");
ret = -EIO;
@@ -695,7 +740,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
fail_map_sg:
dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, &attrs);
+ buf->dma_dir, buf->attrs);
fail_sgt_init:
if (!vma_is_io(buf->vma))
@@ -856,7 +901,7 @@ const struct vb2_mem_ops vb2_dma_contig_memops = {
};
EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
-void *vb2_dma_contig_init_ctx(struct device *dev)
+void *vb2_dma_contig_init_ctx(struct device *dev, struct dma_attrs *attrs)
{
struct vb2_dc_conf *conf;
@@ -866,6 +911,11 @@ void *vb2_dma_contig_init_ctx(struct device *dev)
conf->dev = dev;
+ if (!attrs)
+ init_dma_attrs(&conf->attrs);
+ else
+ conf->attrs = *attrs;
+
return conf;
}
EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);
diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h
index 8197f87..1b85282 100644
--- a/include/media/videobuf2-dma-contig.h
+++ b/include/media/videobuf2-dma-contig.h
@@ -24,7 +24,8 @@ vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, unsigned int plane_no)
return *addr;
}
-void *vb2_dma_contig_init_ctx(struct device *dev);
+void *vb2_dma_contig_init_ctx(struct device *dev,
+ struct dma_attrs *attrs);
void vb2_dma_contig_cleanup_ctx(void *alloc_ctx);
extern const struct vb2_mem_ops vb2_dma_contig_memops;
--
2.1.0.231.g7484e3b
--
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