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ARM: dma-mapping: Allow highmem pages to not have a mapping

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The DMA_ATTR_NO_KERNEL_MAPPING is used to make sure that CMA
pages have no kernel mapping. Add support to make sure that
highmem pages have no mapping.

Change-Id: Ife76df126ecfedf0dba81a35e0de8a1787355b3d
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
This commit is contained in:
Laura Abbott 2013-01-16 18:23:19 -08:00 • committed by David Keitel
parent d224f0017f
commit 0a2980a12b
1 changed files with 20 additions and 9 deletions
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23
arch/arm/mm/dma-mapping.c
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@ -333,10 +333,10 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
prot, caller);
}
static void __dma_free_remap(void *cpu_addr, size_t size)
static void __dma_free_remap(void *cpu_addr, size_t size, bool no_warn)
{
dma_common_free_remap(cpu_addr, size,
VM_ARM_DMA_CONSISTENT | VM_USERMAP);
VM_ARM_DMA_CONSISTENT | VM_USERMAP, no_warn);
}
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
@ -578,6 +578,7 @@ static int __free_from_pool(void *start, size_t size)
return 1;
}
#define NO_KERNEL_MAPPING_DUMMY 0x2222
static void *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page,
const void *caller,
@ -602,11 +603,21 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size,
__dma_clear_buffer(page, size, attrs);
if (PageHighMem(page)) {
ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller);
if (!want_vaddr) {
/*
* Something non-NULL needs to be returned here. Give
* back a dummy address that is unmapped to catch
* clients trying to use the address incorrectly
*/
ptr = (void *)NO_KERNEL_MAPPING_DUMMY;
} else {
ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot,
caller);
if (!ptr) {
dma_release_from_contiguous(dev, page, count);
return NULL;
}
}
} else {
__dma_remap(page, size, prot, want_vaddr);
ptr = page_address(page);
@ -620,7 +631,7 @@ static void __free_from_contiguous(struct device *dev, struct page *page,
void *cpu_addr, size_t size, bool want_vaddr)
{
if (PageHighMem(page))
__dma_free_remap(cpu_addr, size);
__dma_free_remap(cpu_addr, size, true);
else
__dma_remap(page, size, PAGE_KERNEL, false);
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
@ -651,7 +662,7 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
#define __alloc_from_contiguous(dev, size, prot, ret, c, wv) NULL
#define __free_from_pool(cpu_addr, size) 0
#define __free_from_contiguous(dev, page, cpu_addr, size, wv) do { } while (0)
#define __dma_free_remap(cpu_addr, size) do { } while (0)
#define __dma_free_remap(cpu_addr, size, w) do { } while (0)
#endif /* CONFIG_MMU */
@ -838,7 +849,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
return;
} else if (!dev_get_cma_area(dev)) {
if (want_vaddr && !is_coherent)
__dma_free_remap(cpu_addr, size);
__dma_free_remap(cpu_addr, size, false);
__dma_free_buffer(page, size);
} else {
/*