Merge branch 'for-v3.11' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull ARM DMA mapping updates from Marek Szyprowski:
 "This contains important bugfixes and an update for IOMMU integration
  support for ARM architecture"

* 'for-v3.11' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma: Drop __GFP_COMP for iommu dma memory allocations
  ARM: DMA-mapping: mark all !DMA_TO_DEVICE pages in unmapping as clean
  ARM: dma-mapping: NULLify dev->archdata.mapping pointer on detach
  ARM: dma-mapping: convert DMA direction into IOMMU protection attributes
  ARM: dma-mapping: Get pages if the cpu_addr is out of atomic_pool

1 files changed, 32 insertions, 8 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7ec02961dfa0..7f9b1798c6cf 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1328,6 +1328,15 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
         if (gfp & GFP_ATOMIC)
                 return __iommu_alloc_atomic(dev, size, handle);
 
+        /*
+         * Following is a work-around (a.k.a. hack) to prevent pages
+         * with __GFP_COMP being passed to split_page() which cannot
+         * handle them.  The real problem is that this flag probably
+         * should be 0 on ARM as it is not supported on this
+         * platform; see CONFIG_HUGETLBFS.
+         */
+        gfp &= ~(__GFP_COMP);
+
         pages = __iommu_alloc_buffer(dev, size, gfp, attrs);
         if (!pages)
                 return NULL;
@@ -1386,16 +1395,17 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
                           dma_addr_t handle, struct dma_attrs *attrs)
 {
-        struct page **pages = __iommu_get_pages(cpu_addr, attrs);
+        struct page **pages;
         size = PAGE_ALIGN(size);
 
-        if (!pages) {
-                WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+        if (__in_atomic_pool(cpu_addr, size)) {
+                __iommu_free_atomic(dev, cpu_addr, handle, size);
                 return;
         }
 
-        if (__in_atomic_pool(cpu_addr, size)) {
-                __iommu_free_atomic(dev, cpu_addr, handle, size);
+        pages = __iommu_get_pages(cpu_addr, attrs);
+        if (!pages) {
+                WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
                 return;
         }
 
@@ -1650,13 +1660,27 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 {
         struct dma_iommu_mapping *mapping = dev->archdata.mapping;
         dma_addr_t dma_addr;
-        int ret, len = PAGE_ALIGN(size + offset);
+        int ret, prot, len = PAGE_ALIGN(size + offset);
 
         dma_addr = __alloc_iova(mapping, len);
         if (dma_addr == DMA_ERROR_CODE)
                 return dma_addr;
 
-        ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
+        switch (dir) {
+        case DMA_BIDIRECTIONAL:
+                prot = IOMMU_READ | IOMMU_WRITE;
+                break;
+        case DMA_TO_DEVICE:
+                prot = IOMMU_READ;
+                break;
+        case DMA_FROM_DEVICE:
+                prot = IOMMU_WRITE;
+                break;
+        default:
+                prot = 0;
+        }
+
+        ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
         if (ret < 0)
                 goto fail;
 
@@ -1921,7 +1945,7 @@ void arm_iommu_detach_device(struct device *dev)
 
         iommu_detach_device(mapping->domain, dev);
         kref_put(&mapping->kref, release_iommu_mapping);
-        mapping = NULL;
+        dev->archdata.mapping = NULL;
         set_dma_ops(dev, NULL);
 
         pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));