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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>
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
This commit is contained in:
Laura Abbott 2013-01-16 18:23:19 -08:00 committed by Gerrit - the friendly Code Review server
parent 05d90a59b6
commit 19e308d6ca
1 changed files with 23 additions and 11 deletions
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34
arch/arm/mm/dma-mapping.c
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@ -116,7 +116,7 @@ static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller);
static void __dma_free_remap(void *cpu_addr, size_t size);
static void __dma_free_remap(void *cpu_addr, size_t size, bool warn);
static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot);
@ -392,10 +392,10 @@ __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, false);
VM_ARM_DMA_CONSISTENT | VM_USERMAP, no_warn);
}
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
@ -583,12 +583,14 @@ static void __dma_remap(struct page *page, size_t size, pgprot_t prot,
flush_tlb_kernel_range(start, end);
}
#define NO_KERNEL_MAPPING_DUMMY 0x2222
static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
pgprot_t prot, struct page **ret_page,
const void *caller, bool want_vaddr)
{
struct page *page;
void *ptr = NULL;
void *ptr = (void *)NO_KERNEL_MAPPING_DUMMY;
/*
* __alloc_remap_buffer is only called when the device is
* non-coherent
@ -663,10 +665,20 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size,
__dma_clear_buffer(page, size, coherent_flag);
if (PageHighMem(page)) {
ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller);
if (!ptr) {
dma_release_from_contiguous(dev, page, count);
return NULL;
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);
@ -681,7 +693,7 @@ 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, true);
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
@ -777,7 +789,7 @@ static void *remap_allocator_alloc(struct arm_dma_alloc_args *args,
static void remap_allocator_free(struct arm_dma_free_args *args)
{
if (args->want_vaddr)
__dma_free_remap(args->cpu_addr, args->size);
__dma_free_remap(args->cpu_addr, args->size, false);
__dma_free_buffer(args->page, args->size);
}
@ -864,7 +876,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
kfree(buf);
}
return args.want_vaddr ? addr : page;
return addr;
}
/*