dma-mapping: use 'bitmap_zalloc()' when applicable

'dma_mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
improve the semantic and avoid some open-coded arithmetic in allocator
arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index 25fc85a..375fb3c 100644 (file)
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -40,7 +40,6 @@ static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr,
 {
        struct dma_coherent_mem *dma_mem;
        int pages = size >> PAGE_SHIFT;
-       int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
        void *mem_base;
 
        if (!size)
@@ -53,7 +52,7 @@ static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr,
        dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
        if (!dma_mem)
                goto out_unmap_membase;
-       dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+       dma_mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL);
        if (!dma_mem->bitmap)
                goto out_free_dma_mem;
 
@@ -81,7 +80,7 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
                return;
 
        memunmap(mem->virt_base);
-       kfree(mem->bitmap);
+       bitmap_free(mem->bitmap);
        kfree(mem);
 }