drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP

When the DMA_MEMORY_MAP flag is used, memory which can be accessed
directly should be returned, so use memremap(..., MEMREMAP_WC) to
provide a writecombine mapping.

Signed-off-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Brian Starkey 2016-03-22 14:28:03 -07:00 коммит произвёл Linus Torvalds
Родитель c907e0eb43
Коммит 6b03ae0d42
1 изменённых файлов: 16 добавлений и 4 удалений

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@ -2,6 +2,7 @@
* Coherent per-device memory handling.
* Borrowed from i386
*/
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
@ -31,7 +32,10 @@ static bool dma_init_coherent_memory(
if (!size)
goto out;
mem_base = ioremap(phys_addr, size);
if (flags & DMA_MEMORY_MAP)
mem_base = memremap(phys_addr, size, MEMREMAP_WC);
else
mem_base = ioremap(phys_addr, size);
if (!mem_base)
goto out;
@ -54,8 +58,12 @@ static bool dma_init_coherent_memory(
out:
kfree(dma_mem);
if (mem_base)
iounmap(mem_base);
if (mem_base) {
if (flags & DMA_MEMORY_MAP)
memunmap(mem_base);
else
iounmap(mem_base);
}
return false;
}
@ -63,7 +71,11 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
{
if (!mem)
return;
iounmap(mem->virt_base);
if (mem->flags & DMA_MEMORY_MAP)
memunmap(mem->virt_base);
else
iounmap(mem->virt_base);
kfree(mem->bitmap);
kfree(mem);
}