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Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r--arch/arm/mm/dma-mapping.c62
1 files changed, 50 insertions, 12 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ef3e0f3aac9..7f9b1798c6c 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -250,7 +250,7 @@ static void __dma_free_buffer(struct page *page, size_t size)
#ifdef CONFIG_MMU
#ifdef CONFIG_HUGETLB_PAGE
-#error ARM Coherent DMA allocator does not (yet) support huge TLB
+#warning ARM Coherent DMA allocator does not (yet) support huge TLB
#endif
static void *__alloc_from_contiguous(struct device *dev, size_t size,
@@ -880,10 +880,24 @@ static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
/*
- * Mark the D-cache clean for this page to avoid extra flushing.
+ * Mark the D-cache clean for these pages to avoid extra flushing.
*/
- if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
- set_bit(PG_dcache_clean, &page->flags);
+ if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) {
+ unsigned long pfn;
+ size_t left = size;
+
+ pfn = page_to_pfn(page) + off / PAGE_SIZE;
+ off %= PAGE_SIZE;
+ if (off) {
+ pfn++;
+ left -= PAGE_SIZE - off;
+ }
+ while (left >= PAGE_SIZE) {
+ page = pfn_to_page(pfn++);
+ set_bit(PG_dcache_clean, &page->flags);
+ left -= PAGE_SIZE;
+ }
+ }
}
/**
@@ -1314,6 +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;
@@ -1372,16 +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;
}
@@ -1636,13 +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;
@@ -1907,7 +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));