On Mon, 9 Jul 2018 13:20 Marek Szyprowski, m.szyprowski@samsung.com wrote:

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 dd65a941f6ba ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag").

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com

Acked-by: Michał Nazarewicz mina86@mina86.com

---

arch/arm/mm/dma-mapping.c | 5 +++-- arch/arm64/mm/dma-mapping.c | 4 ++-- arch/xtensa/kernel/pci-dma.c | 2 +- drivers/iommu/amd_iommu.c | 2 +- drivers/iommu/intel-iommu.c | 3 ++- include/linux/dma-contiguous.h | 4 ++-- kernel/dma/contiguous.c | 7 +++---- kernel/dma/direct.c | 3 ++- 8 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index be0fa7e39c26..121c6c3ba9e0 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -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;

@@ -1294,7 +1294,8 @@ 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;
  
  

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 61e93f0b5482..072c51fb07d7 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -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);
  
  

@@ -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;

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c index ba4640cc0093..b2c7ba91fb08 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -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));
  

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 64cfe854e0f5..5ec97ffb561a 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2622,7 +2622,7 @@ 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; } diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 869321c594e2..dd2d343428ab 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3746,7 +3746,8 @@ 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);
  

diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h index 3c5a4cb3eb95..f247e8aa5e3d 100644 --- a/include/linux/dma-contiguous.h +++ b/include/linux/dma-contiguous.h @@ -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);

@@ -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; } diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 19ea5d70150c..286d82329eb0 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -178,7 +178,7 @@ 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

@@ -186,13 +186,12 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,

• 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);
  

}

/** diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 8be8106270c2..e0241beeb645 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -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; -- 2.17.1