diff mbox series

[2/2] kernel/dma: rename dma_alloc_direct and dma_map_direct

Message ID YhToPpeuTqdQgC80@MiWiFi-R3L-srv (mailing list archive)
State New
Headers show
Series [1/2] dma-mapping: check dma_mask for streaming mapping allocs | expand

Commit Message

Baoquan He Feb. 22, 2022, 1:42 p.m. UTC 
In the old dma mapping, coherent mapping uses dma_alloc_coherent() to
allocate DMA buffer and mapping; while streaming mapping can only get
memory from slab or buddy allocator, then map with dma_map_single().
In that situation, dma_alloc_direct() checks a direct mapping for
coherent DMA, dma_map_direct() checks a direct mapping for streaming
DMA.

However, several new APIs have been added for streaming mapping, e.g
dma_alloc_pages(). These new APIs take care of DMA buffer allocating
and mapping which are similar with dma_alloc_coherent(). So we should
rename both of them to reflect their real intention to avoid confusion.

       dma_alloc_direct()  ==>  dma_coherent_direct()
       dma_map_direct()    ==>  dma_streaming_direct()

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 kernel/dma/mapping.c | 44 ++++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

Comments

Christoph Hellwig Feb. 22, 2022, 3:59 p.m. UTC | #1 
On Tue, Feb 22, 2022 at 09:42:22PM +0800, Baoquan He wrote:
> In the old dma mapping, coherent mapping uses dma_alloc_coherent() to
> allocate DMA buffer and mapping; while streaming mapping can only get
> memory from slab or buddy allocator, then map with dma_map_single().
> In that situation, dma_alloc_direct() checks a direct mapping for
> coherent DMA, dma_map_direct() checks a direct mapping for streaming
> DMA.
> 
> However, several new APIs have been added for streaming mapping, e.g
> dma_alloc_pages(). These new APIs take care of DMA buffer allocating
> and mapping which are similar with dma_alloc_coherent(). So we should
> rename both of them to reflect their real intention to avoid confusion.
> 
>        dma_alloc_direct()  ==>  dma_coherent_direct()
>        dma_map_direct()    ==>  dma_streaming_direct()

No, these new names are highly misleading.
diff mbox series

Patch

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index e66847aeac67..2835b08e96c6 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -127,13 +127,13 @@  static bool dma_go_direct(struct device *dev, dma_addr_t mask,
  * This allows IOMMU drivers to set a bypass mode if the DMA mask is large
  * enough.
  */
-static inline bool dma_alloc_direct(struct device *dev,
+static inline bool dma_coherent_direct(struct device *dev,
 		const struct dma_map_ops *ops)
 {
 	return dma_go_direct(dev, dev->coherent_dma_mask, ops);
 }
 
-static inline bool dma_map_direct(struct device *dev,
+static inline bool dma_streaming_direct(struct device *dev,
 		const struct dma_map_ops *ops)
 {
 	return dma_go_direct(dev, *dev->dma_mask, ops);
@@ -151,7 +151,7 @@  dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
 	if (WARN_ON_ONCE(!dev->dma_mask))
 		return DMA_MAPPING_ERROR;
 
-	if (dma_map_direct(dev, ops) ||
+	if (dma_streaming_direct(dev, ops) ||
 	    arch_dma_map_page_direct(dev, page_to_phys(page) + offset + size))
 		addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
 	else
@@ -168,7 +168,7 @@  void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (dma_map_direct(dev, ops) ||
+	if (dma_streaming_direct(dev, ops) ||
 	    arch_dma_unmap_page_direct(dev, addr + size))
 		dma_direct_unmap_page(dev, addr, size, dir, attrs);
 	else if (ops->unmap_page)
@@ -188,7 +188,7 @@  static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 	if (WARN_ON_ONCE(!dev->dma_mask))
 		return 0;
 
-	if (dma_map_direct(dev, ops) ||
+	if (dma_streaming_direct(dev, ops) ||
 	    arch_dma_map_sg_direct(dev, sg, nents))
 		ents = dma_direct_map_sg(dev, sg, nents, dir, attrs);
 	else
@@ -277,7 +277,7 @@  void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
 
 	BUG_ON(!valid_dma_direction(dir));
 	debug_dma_unmap_sg(dev, sg, nents, dir);
-	if (dma_map_direct(dev, ops) ||
+	if (dma_streaming_direct(dev, ops) ||
 	    arch_dma_unmap_sg_direct(dev, sg, nents))
 		dma_direct_unmap_sg(dev, sg, nents, dir, attrs);
 	else if (ops->unmap_sg)
@@ -296,7 +296,7 @@  dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
 	if (WARN_ON_ONCE(!dev->dma_mask))
 		return DMA_MAPPING_ERROR;
 
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
 	else if (ops->map_resource)
 		addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
@@ -312,7 +312,7 @@  void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (!dma_map_direct(dev, ops) && ops->unmap_resource)
+	if (!dma_streaming_direct(dev, ops) && ops->unmap_resource)
 		ops->unmap_resource(dev, addr, size, dir, attrs);
 	debug_dma_unmap_resource(dev, addr, size, dir);
 }
@@ -324,7 +324,7 @@  void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
 	else if (ops->sync_single_for_cpu)
 		ops->sync_single_for_cpu(dev, addr, size, dir);
@@ -338,7 +338,7 @@  void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		dma_direct_sync_single_for_device(dev, addr, size, dir);
 	else if (ops->sync_single_for_device)
 		ops->sync_single_for_device(dev, addr, size, dir);
@@ -352,7 +352,7 @@  void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir);
 	else if (ops->sync_sg_for_cpu)
 		ops->sync_sg_for_cpu(dev, sg, nelems, dir);
@@ -366,7 +366,7 @@  void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		dma_direct_sync_sg_for_device(dev, sg, nelems, dir);
 	else if (ops->sync_sg_for_device)
 		ops->sync_sg_for_device(dev, sg, nelems, dir);
@@ -391,7 +391,7 @@  int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_alloc_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
 				size, attrs);
 	if (!ops->get_sgtable)
@@ -430,7 +430,7 @@  bool dma_can_mmap(struct device *dev)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_alloc_direct(dev, ops))
+	if (dma_coherent_direct(dev, ops))
 		return dma_direct_can_mmap(dev);
 	return ops->mmap != NULL;
 }
@@ -455,7 +455,7 @@  int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_alloc_direct(dev, ops))
+	if (dma_coherent_direct(dev, ops))
 		return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
 				attrs);
 	if (!ops->mmap)
@@ -468,7 +468,7 @@  u64 dma_get_required_mask(struct device *dev)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_alloc_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		return dma_direct_get_required_mask(dev);
 	if (ops->get_required_mask)
 		return ops->get_required_mask(dev);
@@ -499,7 +499,7 @@  void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
 	/* let the implementation decide on the zone to allocate from: */
 	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
 
-	if (dma_alloc_direct(dev, ops))
+	if (dma_coherent_direct(dev, ops))
 		cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
 	else if (ops->alloc)
 		cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
@@ -531,7 +531,7 @@  void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 		return;
 
 	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
-	if (dma_alloc_direct(dev, ops))
+	if (dma_coherent_direct(dev, ops))
 		dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
 	else if (ops->free)
 		ops->free(dev, size, cpu_addr, dma_handle, attrs);
@@ -550,7 +550,7 @@  static struct page *__dma_alloc_pages(struct device *dev, size_t size,
         gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
 
 	size = PAGE_ALIGN(size);
-	if (dma_alloc_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		return dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp);
 	if (!ops->alloc_pages)
 		return NULL;
@@ -574,7 +574,7 @@  static void __dma_free_pages(struct device *dev, size_t size, struct page *page,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	size = PAGE_ALIGN(size);
-	if (dma_alloc_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		dma_direct_free_pages(dev, size, page, dma_handle, dir);
 	else if (ops->free_pages)
 		ops->free_pages(dev, size, page, dma_handle, dir);
@@ -769,7 +769,7 @@  size_t dma_max_mapping_size(struct device *dev)
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	size_t size = SIZE_MAX;
 
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		size = dma_direct_max_mapping_size(dev);
 	else if (ops && ops->max_mapping_size)
 		size = ops->max_mapping_size(dev);
@@ -782,7 +782,7 @@  bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_map_direct(dev, ops))
+	if (dma_streaming_direct(dev, ops))
 		return dma_direct_need_sync(dev, dma_addr);
 	return ops->sync_single_for_cpu || ops->sync_single_for_device;
 }