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kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from…
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…_contiguous()

The CMA memory allocator doesn't support standard gfp flags for memory
allocation, so there is no point having it as a parameter for
dma_alloc_from_contiguous() function.  Replace it by a boolean no_warn
argument, which covers all the underlaying cma_alloc() function
supports.

This will help to avoid giving false feeling that this function supports
standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer,
what has already been an issue: see commit dd65a94 ("arm64:
dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag").

Link: http://lkml.kernel.org/r/20180709122020eucas1p21a71b092975cb4a3b9954ffc63f699d1~-sqUFoa-h2939329393eucas1p2Y@eucas1p2.samsung.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Michał Nazarewicz <mina86@mina86.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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mszyprow authored and torvalds committed Aug 17, 2018
1 parent 6518202 commit d834c5a
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Showing 8 changed files with 16 additions and 14 deletions.
5 changes: 3 additions & 2 deletions arch/arm/mm/dma-mapping.c
Original file line number Diff line number Diff line change
Expand Up @@ -594,7 +594,7 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size,
struct page *page;
void *ptr = NULL;

page = dma_alloc_from_contiguous(dev, count, order, gfp);
page = dma_alloc_from_contiguous(dev, count, order, gfp & __GFP_NOWARN);
if (!page)
return NULL;

Expand Down Expand Up @@ -1299,7 +1299,8 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
unsigned long order = get_order(size);
struct page *page;

page = dma_alloc_from_contiguous(dev, count, order, gfp);
page = dma_alloc_from_contiguous(dev, count, order,
gfp & __GFP_NOWARN);
if (!page)
goto error;

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4 changes: 2 additions & 2 deletions arch/arm64/mm/dma-mapping.c
Original file line number Diff line number Diff line change
Expand Up @@ -355,7 +355,7 @@ static int __init atomic_pool_init(void)

if (dev_get_cma_area(NULL))
page = dma_alloc_from_contiguous(NULL, nr_pages,
pool_size_order, GFP_KERNEL);
pool_size_order, false);
else
page = alloc_pages(GFP_DMA32, pool_size_order);

Expand Down Expand Up @@ -573,7 +573,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
struct page *page;

page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size), gfp);
get_order(size), gfp & __GFP_NOWARN);
if (!page)
return NULL;

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2 changes: 1 addition & 1 deletion arch/xtensa/kernel/pci-dma.c
Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,

if (gfpflags_allow_blocking(flag))
page = dma_alloc_from_contiguous(dev, count, get_order(size),
flag);
flag & __GFP_NOWARN);

if (!page)
page = alloc_pages(flag, get_order(size));
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2 changes: 1 addition & 1 deletion drivers/iommu/amd_iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -2620,7 +2620,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
return NULL;

page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size), flag);
get_order(size), flag & __GFP_NOWARN);
if (!page)
return NULL;
}
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3 changes: 2 additions & 1 deletion drivers/iommu/intel-iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -3758,7 +3758,8 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
if (gfpflags_allow_blocking(flags)) {
unsigned int count = size >> PAGE_SHIFT;

page = dma_alloc_from_contiguous(dev, count, order, flags);
page = dma_alloc_from_contiguous(dev, count, order,
flags & __GFP_NOWARN);
if (page && iommu_no_mapping(dev) &&
page_to_phys(page) + size > dev->coherent_dma_mask) {
dma_release_from_contiguous(dev, page, count);
Expand Down
4 changes: 2 additions & 2 deletions include/linux/dma-contiguous.h
Original file line number Diff line number Diff line change
Expand Up @@ -112,7 +112,7 @@ static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size,
}

struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int order, gfp_t gfp_mask);
unsigned int order, bool no_warn);
bool dma_release_from_contiguous(struct device *dev, struct page *pages,
int count);

Expand Down Expand Up @@ -145,7 +145,7 @@ int dma_declare_contiguous(struct device *dev, phys_addr_t size,

static inline
struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int order, gfp_t gfp_mask)
unsigned int order, bool no_warn)
{
return NULL;
}
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7 changes: 3 additions & 4 deletions kernel/dma/contiguous.c
Original file line number Diff line number Diff line change
Expand Up @@ -178,21 +178,20 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
* @dev: Pointer to device for which the allocation is performed.
* @count: Requested number of pages.
* @align: Requested alignment of pages (in PAGE_SIZE order).
* @gfp_mask: GFP flags to use for this allocation.
* @no_warn: Avoid printing message about failed allocation.
*
* This function allocates memory buffer for specified device. It uses
* device specific contiguous memory area if available or the default
* global one. Requires architecture specific dev_get_cma_area() helper
* function.
*/
struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int align, gfp_t gfp_mask)
unsigned int align, bool no_warn)
{
if (align > CONFIG_CMA_ALIGNMENT)
align = CONFIG_CMA_ALIGNMENT;

return cma_alloc(dev_get_cma_area(dev), count, align,
gfp_mask & __GFP_NOWARN);
return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
}

/**
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3 changes: 2 additions & 1 deletion kernel/dma/direct.c
Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
again:
/* CMA can be used only in the context which permits sleeping */
if (gfpflags_allow_blocking(gfp)) {
page = dma_alloc_from_contiguous(dev, count, page_order, gfp);
page = dma_alloc_from_contiguous(dev, count, page_order,
gfp & __GFP_NOWARN);
if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
dma_release_from_contiguous(dev, page, count);
page = NULL;
Expand Down

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