ARM: dma-mapping: fix atomic allocation alignment
Aaro Koskinen [Tue, 7 Aug 2012 12:39:25 +0000 (14:39 +0200)]
The alignment mask is calculated incorrectly. Fixing the calculation
makes strange hangs/lockups disappear during the boot with Amstrad E3
and 3.6-rc1 kernel.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

arch/arm/mm/dma-mapping.c

index 00f86fc..6f64abf 100644 (file)
@@ -423,7 +423,7 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
        unsigned int pageno;
        unsigned long flags;
        void *ptr = NULL;
-       size_t align;
+       unsigned long align_mask;
 
        if (!pool->vaddr) {
                WARN(1, "coherent pool not initialised!\n");
@@ -435,11 +435,11 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
         * small, so align them to their order in pages, minimum is a page
         * size. This helps reduce fragmentation of the DMA space.
         */
-       align = PAGE_SIZE << get_order(size);
+       align_mask = (1 << get_order(size)) - 1;
 
        spin_lock_irqsave(&pool->lock, flags);
        pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,
-                                           0, count, (1 << align) - 1);
+                                           0, count, align_mask);
        if (pageno < pool->nr_pages) {
                bitmap_set(pool->bitmap, pageno, count);
                ptr = pool->vaddr + PAGE_SIZE * pageno;