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

3 files changed, 19 insertions, 9 deletions

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 3003250ac51..62c9457ccd2 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -100,14 +100,18 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
                                  struct dma_attrs *attrs)
 {
         unsigned long dma_mask;
-        struct page *page;
+        struct page *page = NULL;
+        unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
         dma_addr_t addr;
 
         dma_mask = dma_alloc_coherent_mask(dev, flag);
 
         flag |= __GFP_ZERO;
 again:
-        page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
+        if (!(flag & GFP_ATOMIC))
+                page = dma_alloc_from_contiguous(dev, count, get_order(size));
+        if (!page)
+                page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
         if (!page)
                 return NULL;
 
@@ -127,6 +131,16 @@ again:
         return page_address(page);
 }
 
+void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
+                               dma_addr_t dma_addr, struct dma_attrs *attrs)
+{
+        unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+        struct page *page = virt_to_page(vaddr);
+
+        if (!dma_release_from_contiguous(dev, page, count))
+                free_pages((unsigned long)vaddr, get_order(size));
+}
+
 /*
  * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel
  * parameter documentation.
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index f96050685b4..871be4a84c7 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -74,12 +74,6 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
         return nents;
 }
 
-static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
-                                dma_addr_t dma_addr, struct dma_attrs *attrs)
-{
-        free_pages((unsigned long)vaddr, get_order(size));
-}
-
 static void nommu_sync_single_for_device(struct device *dev,
                         dma_addr_t addr, size_t size,
                         enum dma_data_direction dir)
@@ -97,7 +91,7 @@ static void nommu_sync_sg_for_device(struct device *dev,
 
 struct dma_map_ops nommu_dma_ops = {
         .alloc                  = dma_generic_alloc_coherent,
-        .free                   = nommu_free_coherent,
+        .free                   = dma_generic_free_coherent,
         .map_sg                 = nommu_map_sg,
         .map_page               = nommu_map_page,
         .sync_single_for_device = nommu_sync_single_for_device,
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 366c688d619..f2afee6a19c 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -49,6 +49,7 @@
 #include <asm/pci-direct.h>
 #include <linux/init_ohci1394_dma.h>
 #include <linux/kvm_para.h>
+#include <linux/dma-contiguous.h>
 
 #include <linux/errno.h>
 #include <linux/kernel.h>
@@ -925,6 +926,7 @@ void __init setup_arch(char **cmdline_p)
         }
 #endif
         memblock.current_limit = get_max_mapped();
+        dma_contiguous_reserve(0);
 
         /*
          * NOTE: On x86-32, only from this point on, fixmaps are ready for use.