[mm PATCH v2 23/26] dma: Add calls for dma_map_page_attrs and dma_unmap_page_attrs

From: Alexander Duyck
Date: Wed Nov 02 2016 - 13:17:04 EST


Add support for mapping and unmapping a page with attributes. The primary
use for this is currently to allow for us to pass the
DMA_ATTR_SKIP_CPU_SYNC attribute when mapping and unmapping a page. On
some architectures such as ARM the synchronization has significant overhead
and if we are already taking care of the sync_for_cpu and sync_for_device
from the driver there isn't much need to handle this in the map/unmap calls
as well.

Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
---
include/linux/dma-mapping.h | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 08528af..10c5a17 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -243,29 +243,33 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg
ops->unmap_sg(dev, sg, nents, dir, attrs);
}

-static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
- size_t offset, size_t size,
- enum dma_data_direction dir)
+static inline dma_addr_t dma_map_page_attrs(struct device *dev,
+ struct page *page,
+ size_t offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
{
struct dma_map_ops *ops = get_dma_ops(dev);
dma_addr_t addr;

kmemcheck_mark_initialized(page_address(page) + offset, size);
BUG_ON(!valid_dma_direction(dir));
- addr = ops->map_page(dev, page, offset, size, dir, 0);
+ addr = ops->map_page(dev, page, offset, size, dir, attrs);
debug_dma_map_page(dev, page, offset, size, dir, addr, false);

return addr;
}

-static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,
- size_t size, enum dma_data_direction dir)
+static inline void dma_unmap_page_attrs(struct device *dev,
+ dma_addr_t addr, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
{
struct dma_map_ops *ops = get_dma_ops(dev);

BUG_ON(!valid_dma_direction(dir));
if (ops->unmap_page)
- ops->unmap_page(dev, addr, size, dir, 0);
+ ops->unmap_page(dev, addr, size, dir, attrs);
debug_dma_unmap_page(dev, addr, size, dir, false);
}

@@ -385,6 +389,8 @@ static inline void dma_sync_single_range_for_device(struct device *dev,
#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
+#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
+#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)

extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size);