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dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
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Currently the generic dma remap allocator gets a vm_flags passed by
the caller that is a little confusing.  We just introduced a generic
vmalloc-level flag to identify the dma coherent allocations, so use
that everywhere and remove the now pointless argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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Christoph Hellwig committed Sep 4, 2019
1 parent fe9041c commit 5123174
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Showing 5 changed files with 21 additions and 28 deletions.
10 changes: 4 additions & 6 deletions arch/arm/mm/dma-mapping.c
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Original file line number Diff line number Diff line change
Expand Up @@ -343,13 +343,12 @@ static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
return dma_common_contiguous_remap(page, size, VM_DMA_COHERENT,
prot, caller);
return dma_common_contiguous_remap(page, size, prot, caller);
}

static void __dma_free_remap(void *cpu_addr, size_t size)
{
dma_common_free_remap(cpu_addr, size, VM_DMA_COHERENT);
dma_common_free_remap(cpu_addr, size);
}

#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
Expand Down Expand Up @@ -1365,8 +1364,7 @@ static void *
__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
return dma_common_pages_remap(pages, size, VM_DMA_COHERENT, prot,
caller);
return dma_common_pages_remap(pages, size, prot, caller);
}

/*
Expand Down Expand Up @@ -1609,7 +1607,7 @@ void __arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
}

if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0)
dma_common_free_remap(cpu_addr, size, VM_DMA_COHERENT);
dma_common_free_remap(cpu_addr, size);

__iommu_remove_mapping(dev, handle, size);
__iommu_free_buffer(dev, pages, size, attrs);
Expand Down
4 changes: 2 additions & 2 deletions arch/xtensa/kernel/pci-dma.c
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Original file line number Diff line number Diff line change
Expand Up @@ -167,7 +167,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
if (PageHighMem(page)) {
void *p;

p = dma_common_contiguous_remap(page, size, VM_MAP,
p = dma_common_contiguous_remap(page, size,
pgprot_noncached(PAGE_KERNEL),
__builtin_return_address(0));
if (!p) {
Expand All @@ -192,7 +192,7 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
page = virt_to_page(platform_vaddr_to_cached(vaddr));
} else {
#ifdef CONFIG_MMU
dma_common_free_remap(vaddr, size, VM_MAP);
dma_common_free_remap(vaddr, size);
#endif
page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle)));
}
Expand Down
6 changes: 3 additions & 3 deletions drivers/iommu/dma-iommu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -617,7 +617,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
< size)
goto out_free_sg;

vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
vaddr = dma_common_pages_remap(pages, size, prot,
__builtin_return_address(0));
if (!vaddr)
goto out_unmap;
Expand Down Expand Up @@ -941,7 +941,7 @@ static void __iommu_dma_free(struct device *dev, size_t size, void *cpu_addr)
pages = __iommu_dma_get_pages(cpu_addr);
if (!pages)
page = vmalloc_to_page(cpu_addr);
dma_common_free_remap(cpu_addr, alloc_size, VM_USERMAP);
dma_common_free_remap(cpu_addr, alloc_size);
} else {
/* Lowmem means a coherent atomic or CMA allocation */
page = virt_to_page(cpu_addr);
Expand Down Expand Up @@ -979,7 +979,7 @@ static void *iommu_dma_alloc_pages(struct device *dev, size_t size,
pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs);

cpu_addr = dma_common_contiguous_remap(page, alloc_size,
VM_USERMAP, prot, __builtin_return_address(0));
prot, __builtin_return_address(0));
if (!cpu_addr)
goto out_free_pages;

Expand Down
6 changes: 2 additions & 4 deletions include/linux/dma-mapping.h
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Original file line number Diff line number Diff line change
Expand Up @@ -627,13 +627,11 @@ extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
unsigned long attrs);

void *dma_common_contiguous_remap(struct page *page, size_t size,
unsigned long vm_flags,
pgprot_t prot, const void *caller);

void *dma_common_pages_remap(struct page **pages, size_t size,
unsigned long vm_flags, pgprot_t prot,
const void *caller);
void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags);
pgprot_t prot, const void *caller);
void dma_common_free_remap(void *cpu_addr, size_t size);

bool dma_in_atomic_pool(void *start, size_t size);
void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags);
Expand Down
23 changes: 10 additions & 13 deletions kernel/dma/remap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,12 +12,11 @@
#include <linux/vmalloc.h>

static struct vm_struct *__dma_common_pages_remap(struct page **pages,
size_t size, unsigned long vm_flags, pgprot_t prot,
const void *caller)
size_t size, pgprot_t prot, const void *caller)
{
struct vm_struct *area;

area = get_vm_area_caller(size, vm_flags, caller);
area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
if (!area)
return NULL;

Expand All @@ -34,12 +33,11 @@ static struct vm_struct *__dma_common_pages_remap(struct page **pages,
* Cannot be used in non-sleeping contexts
*/
void *dma_common_pages_remap(struct page **pages, size_t size,
unsigned long vm_flags, pgprot_t prot,
const void *caller)
pgprot_t prot, const void *caller)
{
struct vm_struct *area;

area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
area = __dma_common_pages_remap(pages, size, prot, caller);
if (!area)
return NULL;

Expand All @@ -53,7 +51,6 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
* Cannot be used in non-sleeping contexts
*/
void *dma_common_contiguous_remap(struct page *page, size_t size,
unsigned long vm_flags,
pgprot_t prot, const void *caller)
{
int i;
Expand All @@ -67,7 +64,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
for (i = 0; i < (size >> PAGE_SHIFT); i++)
pages[i] = nth_page(page, i);

area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
area = __dma_common_pages_remap(pages, size, prot, caller);

kfree(pages);

Expand All @@ -79,11 +76,11 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
/*
* Unmaps a range previously mapped by dma_common_*_remap
*/
void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
void dma_common_free_remap(void *cpu_addr, size_t size)
{
struct vm_struct *area = find_vm_area(cpu_addr);

if (!area || (area->flags & vm_flags) != vm_flags) {
if (!area || area->flags != VM_DMA_COHERENT) {
WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
return;
}
Expand Down Expand Up @@ -136,7 +133,7 @@ static int __init dma_atomic_pool_init(void)
if (!atomic_pool)
goto free_page;

addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP,
addr = dma_common_contiguous_remap(page, atomic_pool_size,
pgprot_dmacoherent(PAGE_KERNEL),
__builtin_return_address(0));
if (!addr)
Expand All @@ -153,7 +150,7 @@ static int __init dma_atomic_pool_init(void)
return 0;

remove_mapping:
dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
dma_common_free_remap(addr, atomic_pool_size);
destroy_genpool:
gen_pool_destroy(atomic_pool);
atomic_pool = NULL;
Expand Down Expand Up @@ -228,7 +225,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
arch_dma_prep_coherent(page, size);

/* create a coherent mapping */
ret = dma_common_contiguous_remap(page, size, VM_USERMAP,
ret = dma_common_contiguous_remap(page, size,
dma_pgprot(dev, PAGE_KERNEL, attrs),
__builtin_return_address(0));
if (!ret) {
Expand Down

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