1 files changed, 14 insertions, 18 deletions

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index c0b49399225d..c75d5c3470e3 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -24,30 +24,29 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
         struct page *page;
         phys_addr_t paddr;
         void *kvaddr;
-        int need_coh = 1, need_kvaddr = 0;
+        bool need_coh = !(attrs & DMA_ATTR_NON_CONSISTENT);
+
+        /*
+         * __GFP_HIGHMEM flag is cleared by upper layer functions
+         * (in include/linux/dma-mapping.h) so we should never get a
+         * __GFP_HIGHMEM here.
+         */
+        BUG_ON(gfp & __GFP_HIGHMEM);
 
         page = alloc_pages(gfp, order);
         if (!page)
                 return NULL;
 
-        if (attrs & DMA_ATTR_NON_CONSISTENT)
-                need_coh = 0;
-
-        /*
-         * - A coherent buffer needs MMU mapping to enforce non-cachability
-         * - A highmem page needs a virtual handle (hence MMU mapping)
-         *   independent of cachability
-         */
-        if (PageHighMem(page) || need_coh)
-                need_kvaddr = 1;
-
         /* This is linear addr (0x8000_0000 based) */
         paddr = page_to_phys(page);
 
         *dma_handle = paddr;
 
-        /* This is kernel Virtual address (0x7000_0000 based) */
-        if (need_kvaddr) {
+        /*
+         * A coherent buffer needs MMU mapping to enforce non-cachability.
+         * kvaddr is kernel Virtual address (0x7000_0000 based).
+         */
+        if (need_coh) {
                 kvaddr = ioremap_nocache(paddr, size);
                 if (kvaddr == NULL) {
                         __free_pages(page, order);
@@ -78,11 +77,8 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
 {
         phys_addr_t paddr = dma_handle;
         struct page *page = virt_to_page(paddr);
-        int is_non_coh = 1;
-
-        is_non_coh = (attrs & DMA_ATTR_NON_CONSISTENT);
 
-        if (PageHighMem(page) || !is_non_coh)
+        if (!(attrs & DMA_ATTR_NON_CONSISTENT))
                 iounmap((void __force __iomem *)vaddr);
 
         __free_pages(page, get_order(size));