dma-mapping: support highmem in the generic remap allocator

By using __dma_direct_alloc_pages we can deal entirely with struct page
instead of having to derive a kernel virtual address.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index b32bb08..dcc82dd 100644 (file)
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -196,7 +196,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
                gfp_t flags, unsigned long attrs)
 {
        struct page *page = NULL;
-       void *ret, *kaddr;
+       void *ret;
 
        size = PAGE_ALIGN(size);
 
@@ -208,10 +208,9 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
                return ret;
        }
 
-       kaddr = dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs);
-       if (!kaddr)
+       page = __dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs);
+       if (!page)
                return NULL;
-       page = virt_to_page(kaddr);
 
        /* remove any dirty cache lines on the kernel alias */
        arch_dma_prep_coherent(page, size);
@@ -221,7 +220,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
                        arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs),
                        __builtin_return_address(0));
        if (!ret)
-               dma_direct_free_pages(dev, size, kaddr, *dma_handle, attrs);
+               __dma_direct_free_pages(dev, size, page);
        return ret;
 }
 
@@ -229,10 +228,11 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
                dma_addr_t dma_handle, unsigned long attrs)
 {
        if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) {
-               void *kaddr = phys_to_virt(dma_to_phys(dev, dma_handle));
+               phys_addr_t phys = dma_to_phys(dev, dma_handle);
+               struct page *page = pfn_to_page(__phys_to_pfn(phys));
 
                vunmap(vaddr);
-               dma_direct_free_pages(dev, size, kaddr, dma_handle, attrs);
+               __dma_direct_free_pages(dev, size, page);
        }
 }