Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull CMA and ARM DMA-mapping updates from Marek Szyprowski:
 "These patches contain two major updates for DMA mapping subsystem
  (mainly for ARM architecture).  First one is Contiguous Memory
  Allocator (CMA) which makes it possible for device drivers to allocate
  big contiguous chunks of memory after the system has booted.

  The main difference from the similar frameworks is the fact that CMA
  allows to transparently reuse the memory region reserved for the big
  chunk allocation as a system memory, so no memory is wasted when no
  big chunk is allocated.  Once the alloc request is issued, the
  framework migrates system pages to create space for the required big
  chunk of physically contiguous memory.

  For more information one can refer to nice LWN articles:

   - 'A reworked contiguous memory allocator':
		http://lwn.net/Articles/447405/

   - 'CMA and ARM':
		http://lwn.net/Articles/450286/

   - 'A deep dive into CMA':
		http://lwn.net/Articles/486301/

   - and the following thread with the patches and links to all previous
     versions:
		https://lkml.org/lkml/2012/4/3/204

  The main client for this new framework is ARM DMA-mapping subsystem.

  The second part provides a complete redesign in ARM DMA-mapping
  subsystem.  The core implementation has been changed to use common
  struct dma_map_ops based infrastructure with the recent updates for
  new dma attributes merged in v3.4-rc2.  This allows to use more than
  one implementation of dma-mapping calls and change/select them on the
  struct device basis.  The first client of this new infractructure is
  dmabounce implementation which has been completely cut out of the
  core, common code.

  The last patch of this redesign update introduces a new, experimental
  implementation of dma-mapping calls on top of generic IOMMU framework.
  This lets ARM sub-platform to transparently use IOMMU for DMA-mapping
  calls if one provides required IOMMU hardware.

  For more information please refer to the following thread:
		http://www.spinics.net/lists/arm-kernel/msg175729.html

  The last patch merges changes from both updates and provides a
  resolution for the conflicts which cannot be avoided when patches have
  been applied on the same files (mainly arch/arm/mm/dma-mapping.c)."

Acked by Andrew Morton <akpm@linux-foundation.org>:
 "Yup, this one please.  It's had much work, plenty of review and I
  think even Russell is happy with it."

* 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: (28 commits)
  ARM: dma-mapping: use PMD size for section unmap
  cma: fix migration mode
  ARM: integrate CMA with DMA-mapping subsystem
  X86: integrate CMA with DMA-mapping subsystem
  drivers: add Contiguous Memory Allocator
  mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks
  mm: extract reclaim code from __alloc_pages_direct_reclaim()
  mm: Serialize access to min_free_kbytes
  mm: page_isolation: MIGRATE_CMA isolation functions added
  mm: mmzone: MIGRATE_CMA migration type added
  mm: page_alloc: change fallbacks array handling
  mm: page_alloc: introduce alloc_contig_range()
  mm: compaction: export some of the functions
  mm: compaction: introduce isolate_freepages_range()
  mm: compaction: introduce map_pages()
  mm: compaction: introduce isolate_migratepages_range()
  mm: page_alloc: remove trailing whitespace
  ARM: dma-mapping: add support for IOMMU mapper
  ARM: dma-mapping: use alloc, mmap, free from dma_ops
  ARM: dma-mapping: remove redundant code and do the cleanup
  ...

Conflicts:
	arch/x86/include/asm/dma-mapping.h

1 files changed, 40 insertions, 7 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 41aa49b74821..4871e31ae277 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -35,13 +35,39 @@
  */
 #define PAGE_ALLOC_COSTLY_ORDER 3
 
-#define MIGRATE_UNMOVABLE     0
-#define MIGRATE_RECLAIMABLE   1
-#define MIGRATE_MOVABLE       2
-#define MIGRATE_PCPTYPES      3 /* the number of types on the pcp lists */
-#define MIGRATE_RESERVE       3
-#define MIGRATE_ISOLATE       4 /* can't allocate from here */
-#define MIGRATE_TYPES         5
+enum {
+	MIGRATE_UNMOVABLE,
+	MIGRATE_RECLAIMABLE,
+	MIGRATE_MOVABLE,
+	MIGRATE_PCPTYPES,	/* the number of types on the pcp lists */
+	MIGRATE_RESERVE = MIGRATE_PCPTYPES,
+#ifdef CONFIG_CMA
+	/*
+	 * MIGRATE_CMA migration type is designed to mimic the way
+	 * ZONE_MOVABLE works.  Only movable pages can be allocated
+	 * from MIGRATE_CMA pageblocks and page allocator never
+	 * implicitly change migration type of MIGRATE_CMA pageblock.
+	 *
+	 * The way to use it is to change migratetype of a range of
+	 * pageblocks to MIGRATE_CMA which can be done by
+	 * __free_pageblock_cma() function.  What is important though
+	 * is that a range of pageblocks must be aligned to
+	 * MAX_ORDER_NR_PAGES should biggest page be bigger then
+	 * a single pageblock.
+	 */
+	MIGRATE_CMA,
+#endif
+	MIGRATE_ISOLATE,	/* can't allocate from here */
+	MIGRATE_TYPES
+};
+
+#ifdef CONFIG_CMA
+#  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
+#  define cma_wmark_pages(zone)	zone->min_cma_pages
+#else
+#  define is_migrate_cma(migratetype) false
+#  define cma_wmark_pages(zone) 0
+#endif
 
 #define for_each_migratetype_order(order, type) \
 	for (order = 0; order < MAX_ORDER; order++) \
@@ -347,6 +373,13 @@ struct zone {
 	/* see spanned/present_pages for more description */
 	seqlock_t		span_seqlock;
 #endif
+#ifdef CONFIG_CMA
+	/*
+	 * CMA needs to increase watermark levels during the allocation
+	 * process to make sure that the system is not starved.
+	 */
+	unsigned long		min_cma_pages;
+#endif
 	struct free_area	free_area[MAX_ORDER];
 
 #ifndef CONFIG_SPARSEMEM