[ARM] dma: provide a better dma_map_page() implementation
We can translate a struct page directly to a DMA address using
page_to_dma(). No need to use page_address() followed by
virt_to_dma().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 35c72bc..c7f23ce 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -412,6 +412,19 @@
return dma_addr;
}
+dma_addr_t dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir)
+{
+ dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n",
+ __func__, page, offset, size, dir);
+
+ BUG_ON(dir == DMA_NONE);
+
+ return map_single(dev, page_address(page) + offset, size, dir);
+}
+EXPORT_SYMBOL(dma_map_page);
+
/*
* see if a mapped address was really a "safe" buffer and if so, copy
* the data from the safe buffer back to the unsafe buffer and free up
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index eff9548..856ee1b 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -227,13 +227,22 @@
* can regain ownership by calling dma_unmap_page() or
* dma_sync_single_for_cpu().
*/
+#ifndef CONFIG_DMABOUNCE
static inline dma_addr_t
dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir)
{
- return dma_map_single(dev, page_address(page) + offset, size, dir);
+ if (!arch_is_coherent())
+ dma_cache_maint(page_address(page) + offset, size, dir);
+
+ return page_to_dma(dev, page) + offset;
}
+#else
+extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir);
+#endif
/**
* dma_unmap_single - unmap a single buffer previously mapped