[PATCH 1/3] mm: alloc_contig_range: allow to specify GFP mask

[PATCH 1/3] mm: alloc_contig_range: allow to specify GFP mask

[Lucas Stach]

Currently alloc_contig_range assumes that the compaction should
be done with the default GFP_KERNEL flags. This is probably
right for all current uses of this interface, but may change as
CMA is used in more use-cases (including being the default DMA
memory allocator on some platforms).

Change the function prototype, to allow for passing through the
GFP mask set by upper layers. No functional change in this patch,
just making the assumptions a bit more obvious.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 include/linux/gfp.h | 2 +-
 mm/cma.c            | 3 ++-
 mm/hugetlb.c        | 3 ++-
 mm/page_alloc.c     | 5 +++--
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 4175dca4ac39..1efa221e0e1d 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -549,7 +549,7 @@ static inline bool pm_suspended_storage(void)
 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
 /* The below functions must be run on a range from a single zone. */
 extern int alloc_contig_range(unsigned long start, unsigned long end,
-			      unsigned migratetype);
+			      unsigned migratetype, gfp_t gfp_mask);
 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 #endif
 
diff --git a/mm/cma.c b/mm/cma.c
index c960459eda7e..fbd67d866f67 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -407,7 +407,8 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 
 		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
 		mutex_lock(&cma_mutex);
-		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
+		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
+					 GFP_KERNEL);
 		mutex_unlock(&cma_mutex);
 		if (ret == 0) {
 			page = pfn_to_page(pfn);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3edb759c5c7d..6ed8b160fc0d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1051,7 +1051,8 @@ static int __alloc_gigantic_page(unsigned long start_pfn,
 				unsigned long nr_pages)
 {
 	unsigned long end_pfn = start_pfn + nr_pages;
-	return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
+	return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
+				  GFP_KERNEL);
 }
 
 static bool pfn_range_valid_gigantic(struct zone *z,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index eced9fee582b..6d392d8dee36 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7230,6 +7230,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
  *			#MIGRATE_MOVABLE or #MIGRATE_CMA).  All pageblocks
  *			in range must have the same migratetype and it must
  *			be either of the two.
+ * @gfp_mask:	GFP mask to use during compaction
  *
  * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
  * aligned, however it's the caller's responsibility to guarantee that
@@ -7243,7 +7244,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
  * need to be freed with free_contig_range().
  */
 int alloc_contig_range(unsigned long start, unsigned long end,
-		       unsigned migratetype)
+		       unsigned migratetype, gfp_t gfp_mask)
 {
 	unsigned long outer_start, outer_end;
 	unsigned int order;
@@ -7255,7 +7256,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 		.zone = page_zone(pfn_to_page(start)),
 		.mode = MIGRATE_SYNC,
 		.ignore_skip_hint = true,
-		.gfp_mask = GFP_KERNEL,
+		.gfp_mask = gfp_mask,
 	};
 	INIT_LIST_HEAD(&cc.migratepages);
 
-- 
2.11.0

[PATCH 2/3] mm: cma_alloc: allow to specify GFP mask

[Lucas Stach]

Most users of this interface just want to use it with the default
GFP_KERNEL flags, but for cases where DMA memory is allocated it may
be called from a different context.

No functional change yet, just passing through the flag to the
underlying alloc_contig_range function.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 arch/powerpc/kvm/book3s_hv_builtin.c | 3 ++-
 drivers/base/dma-contiguous.c        | 2 +-
 include/linux/cma.h                  | 3 ++-
 mm/cma.c                             | 5 +++--
 mm/cma_debug.c                       | 2 +-
 5 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 5bb24be0b346..56a62d97ab2d 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -56,7 +56,8 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages)
 {
 	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
 
-	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES));
+	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
+			 GFP_KERNEL);
 }
 EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
 
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index e167a1e1bccb..d1a9cbabc627 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -193,7 +193,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
 	if (align > CONFIG_CMA_ALIGNMENT)
 		align = CONFIG_CMA_ALIGNMENT;
 
-	return cma_alloc(dev_get_cma_area(dev), count, align);
+	return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL);
 }
 
 /**
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 6f0a91b37f68..03f32d0bd1d8 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -29,6 +29,7 @@ extern int __init cma_declare_contiguous(phys_addr_t base,
 extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
 					unsigned int order_per_bit,
 					struct cma **res_cma);
-extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align);
+extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
+			      gfp_t gfp_mask);
 extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
 #endif
diff --git a/mm/cma.c b/mm/cma.c
index fbd67d866f67..a33ddfde315d 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -362,7 +362,8 @@ int __init cma_declare_contiguous(phys_addr_t base,
  * This function allocates part of contiguous memory on specific
  * contiguous memory area.
  */
-struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
+struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
+		       gfp_t gfp_mask)
 {
 	unsigned long mask, offset;
 	unsigned long pfn = -1;
@@ -408,7 +409,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
 		mutex_lock(&cma_mutex);
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
-					 GFP_KERNEL);
+					 gfp_mask);
 		mutex_unlock(&cma_mutex);
 		if (ret == 0) {
 			page = pfn_to_page(pfn);
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index f8e4b60db167..ffc0c3d0ae64 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -138,7 +138,7 @@ static int cma_alloc_mem(struct cma *cma, int count)
 	if (!mem)
 		return -ENOMEM;
 
-	p = cma_alloc(cma, count, 0);
+	p = cma_alloc(cma, count, 0, GFP_KERNEL);
 	if (!p) {
 		kfree(mem);
 		return -ENOMEM;
-- 
2.11.0

[PATCH 3/3] mm: wire up GFP flag passing in dma_alloc_from_contiguous

[Lucas Stach]

The callers of the DMA alloc functions already provide the proper
context GFP flags. Make sure to pass them through to the CMA
allocator, to make the CMA compaction context aware.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 arch/arm/mm/dma-mapping.c      | 16 +++++++++-------
 arch/arm64/mm/dma-mapping.c    |  4 ++--
 arch/mips/mm/dma-default.c     |  4 ++--
 arch/x86/kernel/pci-dma.c      |  3 ++-
 arch/xtensa/kernel/pci-dma.c   |  3 ++-
 drivers/base/dma-contiguous.c  |  5 +++--
 drivers/iommu/amd_iommu.c      |  2 +-
 drivers/iommu/intel-iommu.c    |  2 +-
 include/linux/dma-contiguous.h |  4 ++--
 9 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab7710002ba6..4d6ec7d821c8 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -349,7 +349,7 @@ static void __dma_free_buffer(struct page *page, size_t size)
 static void *__alloc_from_contiguous(struct device *dev, size_t size,
 				     pgprot_t prot, struct page **ret_page,
 				     const void *caller, bool want_vaddr,
-				     int coherent_flag);
+				     int coherent_flag, gfp_t gfp);
 
 static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
 				 pgprot_t prot, struct page **ret_page,
@@ -420,7 +420,8 @@ static int __init atomic_pool_init(void)
 	 */
 	if (dev_get_cma_area(NULL))
 		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,
-				      &page, atomic_pool_init, true, NORMAL);
+				      &page, atomic_pool_init, true, NORMAL,
+				      GFP_KERNEL);
 	else
 		ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,
 					   &page, atomic_pool_init, true);
@@ -594,14 +595,14 @@ static int __free_from_pool(void *start, size_t size)
 static void *__alloc_from_contiguous(struct device *dev, size_t size,
 				     pgprot_t prot, struct page **ret_page,
 				     const void *caller, bool want_vaddr,
-				     int coherent_flag)
+				     int coherent_flag, gfp_t gfp)
 {
 	unsigned long order = get_order(size);
 	size_t count = size >> PAGE_SHIFT;
 	struct page *page;
 	void *ptr = NULL;
 
-	page = dma_alloc_from_contiguous(dev, count, order);
+	page = dma_alloc_from_contiguous(dev, count, order, gfp);
 	if (!page)
 		return NULL;
 
@@ -655,7 +656,7 @@ static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
 #define __get_dma_pgprot(attrs, prot)				__pgprot(0)
 #define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv)	NULL
 #define __alloc_from_pool(size, ret_page)			NULL
-#define __alloc_from_contiguous(dev, size, prot, ret, c, wv, coherent_flag)	NULL
+#define __alloc_from_contiguous(dev, size, prot, ret, c, wv, coherent_flag, gfp)	NULL
 #define __free_from_pool(cpu_addr, size)			do { } while (0)
 #define __free_from_contiguous(dev, page, cpu_addr, size, wv)	do { } while (0)
 #define __dma_free_remap(cpu_addr, size)			do { } while (0)
@@ -697,7 +698,8 @@ static void *cma_allocator_alloc(struct arm_dma_alloc_args *args,
 {
 	return __alloc_from_contiguous(args->dev, args->size, args->prot,
 				       ret_page, args->caller,
-				       args->want_vaddr, args->coherent_flag);
+				       args->want_vaddr, args->coherent_flag,
+				       args->gfp);
 }
 
 static void cma_allocator_free(struct arm_dma_free_args *args)
@@ -1293,7 +1295,7 @@ 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);
+		page = dma_alloc_from_contiguous(dev, count, order, gfp);
 		if (!page)
 			goto error;
 
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index e04082700bb1..b998f56e6a53 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -107,7 +107,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
 		void *addr;
 
 		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
-							get_order(size));
+						 get_order(size), flags);
 		if (!page)
 			return NULL;
 
@@ -379,7 +379,7 @@ static int __init atomic_pool_init(void)
 
 	if (dev_get_cma_area(NULL))
 		page = dma_alloc_from_contiguous(NULL, nr_pages,
-							pool_size_order);
+						 pool_size_order, GFP_KERNEL);
 	else
 		page = alloc_pages(GFP_DMA, pool_size_order);
 
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index a39c36af97ad..1895a692efd4 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -148,8 +148,8 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 	gfp = massage_gfp_flags(dev, gfp);
 
 	if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
-		page = dma_alloc_from_contiguous(dev,
-					count, get_order(size));
+		page = dma_alloc_from_contiguous(dev, count, get_order(size),
+						 gfp);
 	if (!page)
 		page = alloc_pages(gfp, get_order(size));
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index d30c37750765..d5c223c9cf11 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -91,7 +91,8 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 	page = NULL;
 	/* CMA can be used only in the context which permits sleeping */
 	if (gfpflags_allow_blocking(flag)) {
-		page = dma_alloc_from_contiguous(dev, count, get_order(size));
+		page = dma_alloc_from_contiguous(dev, count, get_order(size),
+						 flag);
 		if (page && page_to_phys(page) + size > dma_mask) {
 			dma_release_from_contiguous(dev, page, count);
 			page = NULL;
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 70e362e6038e..34c1f9fa6acc 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -158,7 +158,8 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
 		flag |= GFP_DMA;
 
 	if (gfpflags_allow_blocking(flag))
-		page = dma_alloc_from_contiguous(dev, count, get_order(size));
+		page = dma_alloc_from_contiguous(dev, count, get_order(size),
+						 flag);
 
 	if (!page)
 		page = alloc_pages(flag, get_order(size));
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index d1a9cbabc627..b55804cac4c4 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -181,6 +181,7 @@ 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.
  *
  * This function allocates memory buffer for specified device. It uses
  * device specific contiguous memory area if available or the default
@@ -188,12 +189,12 @@ 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)
+				       unsigned int align, gfp_t gfp_mask)
 {
 	if (align > CONFIG_CMA_ALIGNMENT)
 		align = CONFIG_CMA_ALIGNMENT;
 
-	return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL);
+	return cma_alloc(dev_get_cma_area(dev), count, align, gfp_mask);
 }
 
 /**
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 3ef0f42984f2..bd2e335cdf39 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2668,7 +2668,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
 			return NULL;
 
 		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
-						 get_order(size));
+						 get_order(size), flag);
 		if (!page)
 			return NULL;
 	}
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 8a185250ae5a..3f804eb4299a 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3827,7 +3827,7 @@ 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);
+		page = dma_alloc_from_contiguous(dev, count, order, flags);
 		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 fec734df1524..b67bf6ac907d 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);
+				       unsigned int order, gfp_t gfp_mask);
 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)
+				       unsigned int order, gfp_t gfp_mask)
 {
 	return NULL;
 }
-- 
2.11.0

Re: [PATCH 1/3] mm: alloc_contig_range: allow to specify GFP mask

[Vlastimil Babka]

On 01/19/2017 06:07 PM, Lucas Stach wrote:
> Currently alloc_contig_range assumes that the compaction should
> be done with the default GFP_KERNEL flags. This is probably
> right for all current uses of this interface, but may change as
> CMA is used in more use-cases (including being the default DMA
> memory allocator on some platforms).
> 
> Change the function prototype, to allow for passing through the
> GFP mask set by upper layers. No functional change in this patch,
> just making the assumptions a bit more obvious.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

[...]

> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index eced9fee582b..6d392d8dee36 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7230,6 +7230,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
>   *			#MIGRATE_MOVABLE or #MIGRATE_CMA).  All pageblocks
>   *			in range must have the same migratetype and it must
>   *			be either of the two.
> + * @gfp_mask:	GFP mask to use during compaction
>   *
>   * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
>   * aligned, however it's the caller's responsibility to guarantee that
> @@ -7243,7 +7244,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
>   * need to be freed with free_contig_range().
>   */
>  int alloc_contig_range(unsigned long start, unsigned long end,
> -		       unsigned migratetype)
> +		       unsigned migratetype, gfp_t gfp_mask)
>  {
>  	unsigned long outer_start, outer_end;
>  	unsigned int order;
> @@ -7255,7 +7256,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
>  		.zone = page_zone(pfn_to_page(start)),
>  		.mode = MIGRATE_SYNC,
>  		.ignore_skip_hint = true,
> -		.gfp_mask = GFP_KERNEL,
> +		.gfp_mask = gfp_mask,

I think you should apply memalloc_noio_flags() here (and Michal should
then convert it to the new name in his scoped gfp_nofs series). Note
that then it's technically a functional change, but it's needed.
Otherwise looks good.

>  	};
>  	INIT_LIST_HEAD(&cc.migratepages);
>  
> 

Re: [PATCH 2/3] mm: cma_alloc: allow to specify GFP mask

[Vlastimil Babka]

On 01/19/2017 06:07 PM, Lucas Stach wrote:
> Most users of this interface just want to use it with the default
> GFP_KERNEL flags, but for cases where DMA memory is allocated it may
> be called from a different context.
> 
> No functional change yet, just passing through the flag to the
> underlying alloc_contig_range function.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  arch/powerpc/kvm/book3s_hv_builtin.c | 3 ++-
>  drivers/base/dma-contiguous.c        | 2 +-
>  include/linux/cma.h                  | 3 ++-
>  mm/cma.c                             | 5 +++--
>  mm/cma_debug.c                       | 2 +-
>  5 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
> index 5bb24be0b346..56a62d97ab2d 100644
> --- a/arch/powerpc/kvm/book3s_hv_builtin.c
> +++ b/arch/powerpc/kvm/book3s_hv_builtin.c
> @@ -56,7 +56,8 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages)
>  {
>  	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
>  
> -	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES));
> +	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
> +			 GFP_KERNEL);
>  }
>  EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
>  
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index e167a1e1bccb..d1a9cbabc627 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -193,7 +193,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
>  	if (align > CONFIG_CMA_ALIGNMENT)
>  		align = CONFIG_CMA_ALIGNMENT;
>  
> -	return cma_alloc(dev_get_cma_area(dev), count, align);
> +	return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL);
>  }
>  
>  /**
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 6f0a91b37f68..03f32d0bd1d8 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -29,6 +29,7 @@ extern int __init cma_declare_contiguous(phys_addr_t base,
>  extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>  					unsigned int order_per_bit,
>  					struct cma **res_cma);
> -extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align);
> +extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +			      gfp_t gfp_mask);
>  extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
>  #endif
> diff --git a/mm/cma.c b/mm/cma.c
> index fbd67d866f67..a33ddfde315d 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -362,7 +362,8 @@ int __init cma_declare_contiguous(phys_addr_t base,
>   * This function allocates part of contiguous memory on specific
>   * contiguous memory area.
>   */
> -struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
> +struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +		       gfp_t gfp_mask)
>  {
>  	unsigned long mask, offset;
>  	unsigned long pfn = -1;
> @@ -408,7 +409,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
>  		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
>  		mutex_lock(&cma_mutex);
>  		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
> -					 GFP_KERNEL);
> +					 gfp_mask);
>  		mutex_unlock(&cma_mutex);
>  		if (ret == 0) {
>  			page = pfn_to_page(pfn);
> diff --git a/mm/cma_debug.c b/mm/cma_debug.c
> index f8e4b60db167..ffc0c3d0ae64 100644
> --- a/mm/cma_debug.c
> +++ b/mm/cma_debug.c
> @@ -138,7 +138,7 @@ static int cma_alloc_mem(struct cma *cma, int count)
>  	if (!mem)
>  		return -ENOMEM;
>  
> -	p = cma_alloc(cma, count, 0);
> +	p = cma_alloc(cma, count, 0, GFP_KERNEL);
>  	if (!p) {
>  		kfree(mem);
>  		return -ENOMEM;
> 

Re: [PATCH 3/3] mm: wire up GFP flag passing in dma_alloc_from_contiguous

[Vlastimil Babka]

On 01/19/2017 06:07 PM, Lucas Stach wrote:
> The callers of the DMA alloc functions already provide the proper
> context GFP flags. Make sure to pass them through to the CMA
> allocator, to make the CMA compaction context aware.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

Re: [PATCH 1/3] mm: alloc_contig_range: allow to specify GFP mask

[Michal Hocko]

On Fri 20-01-17 13:35:40, Vlastimil Babka wrote:
> On 01/19/2017 06:07 PM, Lucas Stach wrote:
[...]
> > @@ -7255,7 +7256,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
> >  		.zone = page_zone(pfn_to_page(start)),
> >  		.mode = MIGRATE_SYNC,
> >  		.ignore_skip_hint = true,
> > -		.gfp_mask = GFP_KERNEL,
> > +		.gfp_mask = gfp_mask,
> 
> I think you should apply memalloc_noio_flags() here (and Michal should
> then convert it to the new name in his scoped gfp_nofs series). Note
> that then it's technically a functional change, but it's needed.
> Otherwise looks good.

yes, with that added, feel free to add
Acked-by: Michal Hocko <mhocko@suse.com>

> 
> >  	};
> >  	INIT_LIST_HEAD(&cc.migratepages);
> >  
> > 

-- 
Michal Hocko
SUSE Labs

Re: [PATCH 2/3] mm: cma_alloc: allow to specify GFP mask

[Michal Hocko]

On Thu 19-01-17 18:07:06, Lucas Stach wrote:
> Most users of this interface just want to use it with the default
> GFP_KERNEL flags, but for cases where DMA memory is allocated it may
> be called from a different context.
> 
> No functional change yet, just passing through the flag to the
> underlying alloc_contig_range function.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  arch/powerpc/kvm/book3s_hv_builtin.c | 3 ++-
>  drivers/base/dma-contiguous.c        | 2 +-
>  include/linux/cma.h                  | 3 ++-
>  mm/cma.c                             | 5 +++--
>  mm/cma_debug.c                       | 2 +-
>  5 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
> index 5bb24be0b346..56a62d97ab2d 100644
> --- a/arch/powerpc/kvm/book3s_hv_builtin.c
> +++ b/arch/powerpc/kvm/book3s_hv_builtin.c
> @@ -56,7 +56,8 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages)
>  {
>  	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
>  
> -	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES));
> +	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
> +			 GFP_KERNEL);
>  }
>  EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
>  
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index e167a1e1bccb..d1a9cbabc627 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -193,7 +193,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
>  	if (align > CONFIG_CMA_ALIGNMENT)
>  		align = CONFIG_CMA_ALIGNMENT;
>  
> -	return cma_alloc(dev_get_cma_area(dev), count, align);
> +	return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL);
>  }
>  
>  /**
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 6f0a91b37f68..03f32d0bd1d8 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -29,6 +29,7 @@ extern int __init cma_declare_contiguous(phys_addr_t base,
>  extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>  					unsigned int order_per_bit,
>  					struct cma **res_cma);
> -extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align);
> +extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +			      gfp_t gfp_mask);
>  extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
>  #endif
> diff --git a/mm/cma.c b/mm/cma.c
> index fbd67d866f67..a33ddfde315d 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -362,7 +362,8 @@ int __init cma_declare_contiguous(phys_addr_t base,
>   * This function allocates part of contiguous memory on specific
>   * contiguous memory area.
>   */
> -struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
> +struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +		       gfp_t gfp_mask)
>  {
>  	unsigned long mask, offset;
>  	unsigned long pfn = -1;
> @@ -408,7 +409,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
>  		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
>  		mutex_lock(&cma_mutex);
>  		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
> -					 GFP_KERNEL);
> +					 gfp_mask);
>  		mutex_unlock(&cma_mutex);
>  		if (ret == 0) {
>  			page = pfn_to_page(pfn);
> diff --git a/mm/cma_debug.c b/mm/cma_debug.c
> index f8e4b60db167..ffc0c3d0ae64 100644
> --- a/mm/cma_debug.c
> +++ b/mm/cma_debug.c
> @@ -138,7 +138,7 @@ static int cma_alloc_mem(struct cma *cma, int count)
>  	if (!mem)
>  		return -ENOMEM;
>  
> -	p = cma_alloc(cma, count, 0);
> +	p = cma_alloc(cma, count, 0, GFP_KERNEL);
>  	if (!p) {
>  		kfree(mem);
>  		return -ENOMEM;
> -- 
> 2.11.0
> 

-- 
Michal Hocko
SUSE Labs

Re: [PATCH 3/3] mm: wire up GFP flag passing in dma_alloc_from_contiguous

[Michal Hocko]

On Thu 19-01-17 18:07:07, Lucas Stach wrote:
> The callers of the DMA alloc functions already provide the proper
> context GFP flags. Make sure to pass them through to the CMA
> allocator, to make the CMA compaction context aware.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

Looks good to me
Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  arch/arm/mm/dma-mapping.c      | 16 +++++++++-------
>  arch/arm64/mm/dma-mapping.c    |  4 ++--
>  arch/mips/mm/dma-default.c     |  4 ++--
>  arch/x86/kernel/pci-dma.c      |  3 ++-
>  arch/xtensa/kernel/pci-dma.c   |  3 ++-
>  drivers/base/dma-contiguous.c  |  5 +++--
>  drivers/iommu/amd_iommu.c      |  2 +-
>  drivers/iommu/intel-iommu.c    |  2 +-
>  include/linux/dma-contiguous.h |  4 ++--
>  9 files changed, 24 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index ab7710002ba6..4d6ec7d821c8 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -349,7 +349,7 @@ static void __dma_free_buffer(struct page *page, size_t size)
>  static void *__alloc_from_contiguous(struct device *dev, size_t size,
>  				     pgprot_t prot, struct page **ret_page,
>  				     const void *caller, bool want_vaddr,
> -				     int coherent_flag);
> +				     int coherent_flag, gfp_t gfp);
>  
>  static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
>  				 pgprot_t prot, struct page **ret_page,
> @@ -420,7 +420,8 @@ static int __init atomic_pool_init(void)
>  	 */
>  	if (dev_get_cma_area(NULL))
>  		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,
> -				      &page, atomic_pool_init, true, NORMAL);
> +				      &page, atomic_pool_init, true, NORMAL,
> +				      GFP_KERNEL);
>  	else
>  		ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,
>  					   &page, atomic_pool_init, true);
> @@ -594,14 +595,14 @@ static int __free_from_pool(void *start, size_t size)
>  static void *__alloc_from_contiguous(struct device *dev, size_t size,
>  				     pgprot_t prot, struct page **ret_page,
>  				     const void *caller, bool want_vaddr,
> -				     int coherent_flag)
> +				     int coherent_flag, gfp_t gfp)
>  {
>  	unsigned long order = get_order(size);
>  	size_t count = size >> PAGE_SHIFT;
>  	struct page *page;
>  	void *ptr = NULL;
>  
> -	page = dma_alloc_from_contiguous(dev, count, order);
> +	page = dma_alloc_from_contiguous(dev, count, order, gfp);
>  	if (!page)
>  		return NULL;
>  
> @@ -655,7 +656,7 @@ static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
>  #define __get_dma_pgprot(attrs, prot)				__pgprot(0)
>  #define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv)	NULL
>  #define __alloc_from_pool(size, ret_page)			NULL
> -#define __alloc_from_contiguous(dev, size, prot, ret, c, wv, coherent_flag)	NULL
> +#define __alloc_from_contiguous(dev, size, prot, ret, c, wv, coherent_flag, gfp)	NULL
>  #define __free_from_pool(cpu_addr, size)			do { } while (0)
>  #define __free_from_contiguous(dev, page, cpu_addr, size, wv)	do { } while (0)
>  #define __dma_free_remap(cpu_addr, size)			do { } while (0)
> @@ -697,7 +698,8 @@ static void *cma_allocator_alloc(struct arm_dma_alloc_args *args,
>  {
>  	return __alloc_from_contiguous(args->dev, args->size, args->prot,
>  				       ret_page, args->caller,
> -				       args->want_vaddr, args->coherent_flag);
> +				       args->want_vaddr, args->coherent_flag,
> +				       args->gfp);
>  }
>  
>  static void cma_allocator_free(struct arm_dma_free_args *args)
> @@ -1293,7 +1295,7 @@ 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);
> +		page = dma_alloc_from_contiguous(dev, count, order, gfp);
>  		if (!page)
>  			goto error;
>  
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index e04082700bb1..b998f56e6a53 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -107,7 +107,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
>  		void *addr;
>  
>  		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
> -							get_order(size));
> +						 get_order(size), flags);
>  		if (!page)
>  			return NULL;
>  
> @@ -379,7 +379,7 @@ static int __init atomic_pool_init(void)
>  
>  	if (dev_get_cma_area(NULL))
>  		page = dma_alloc_from_contiguous(NULL, nr_pages,
> -							pool_size_order);
> +						 pool_size_order, GFP_KERNEL);
>  	else
>  		page = alloc_pages(GFP_DMA, pool_size_order);
>  
> diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
> index a39c36af97ad..1895a692efd4 100644
> --- a/arch/mips/mm/dma-default.c
> +++ b/arch/mips/mm/dma-default.c
> @@ -148,8 +148,8 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
>  	gfp = massage_gfp_flags(dev, gfp);
>  
>  	if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
> -		page = dma_alloc_from_contiguous(dev,
> -					count, get_order(size));
> +		page = dma_alloc_from_contiguous(dev, count, get_order(size),
> +						 gfp);
>  	if (!page)
>  		page = alloc_pages(gfp, get_order(size));
>  
> diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
> index d30c37750765..d5c223c9cf11 100644
> --- a/arch/x86/kernel/pci-dma.c
> +++ b/arch/x86/kernel/pci-dma.c
> @@ -91,7 +91,8 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
>  	page = NULL;
>  	/* CMA can be used only in the context which permits sleeping */
>  	if (gfpflags_allow_blocking(flag)) {
> -		page = dma_alloc_from_contiguous(dev, count, get_order(size));
> +		page = dma_alloc_from_contiguous(dev, count, get_order(size),
> +						 flag);
>  		if (page && page_to_phys(page) + size > dma_mask) {
>  			dma_release_from_contiguous(dev, page, count);
>  			page = NULL;
> diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
> index 70e362e6038e..34c1f9fa6acc 100644
> --- a/arch/xtensa/kernel/pci-dma.c
> +++ b/arch/xtensa/kernel/pci-dma.c
> @@ -158,7 +158,8 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
>  		flag |= GFP_DMA;
>  
>  	if (gfpflags_allow_blocking(flag))
> -		page = dma_alloc_from_contiguous(dev, count, get_order(size));
> +		page = dma_alloc_from_contiguous(dev, count, get_order(size),
> +						 flag);
>  
>  	if (!page)
>  		page = alloc_pages(flag, get_order(size));
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index d1a9cbabc627..b55804cac4c4 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -181,6 +181,7 @@ 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.
>   *
>   * This function allocates memory buffer for specified device. It uses
>   * device specific contiguous memory area if available or the default
> @@ -188,12 +189,12 @@ 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)
> +				       unsigned int align, gfp_t gfp_mask)
>  {
>  	if (align > CONFIG_CMA_ALIGNMENT)
>  		align = CONFIG_CMA_ALIGNMENT;
>  
> -	return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL);
> +	return cma_alloc(dev_get_cma_area(dev), count, align, gfp_mask);
>  }
>  
>  /**
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 3ef0f42984f2..bd2e335cdf39 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -2668,7 +2668,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
>  			return NULL;
>  
>  		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
> -						 get_order(size));
> +						 get_order(size), flag);
>  		if (!page)
>  			return NULL;
>  	}
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 8a185250ae5a..3f804eb4299a 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3827,7 +3827,7 @@ 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);
> +		page = dma_alloc_from_contiguous(dev, count, order, flags);
>  		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 fec734df1524..b67bf6ac907d 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);
> +				       unsigned int order, gfp_t gfp_mask);
>  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)
> +				       unsigned int order, gfp_t gfp_mask)
>  {
>  	return NULL;
>  }
> -- 
> 2.11.0
> 

-- 
Michal Hocko
SUSE Labs