[PATCH 3/4] ARC: refactor arch/arc/mm/dma.c

From: Eugeniy Paltsev
Date: Tue Jul 24 2018 - 06:10:44 EST


Refactoring, no functional change intended.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
---
arch/arc/mm/dma.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index b693818cd8e5..46584c7c2858 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -27,30 +27,24 @@ 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);

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
+ * - A highmem page needs a virtual handle (hence MMU mapping)
+ * independent of cachability.
+ * kvaddr is kernel Virtual address (0x7000_0000 based)
+ */
+ if (PageHighMem(page) || need_coh) {
kvaddr = ioremap_nocache(paddr, size);
if (kvaddr == NULL) {
__free_pages(page, order);
@@ -81,11 +75,9 @@ 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);
+ bool is_coh = !(attrs & DMA_ATTR_NON_CONSISTENT);

- if (PageHighMem(page) || !is_non_coh)
+ if (PageHighMem(page) || is_coh)
iounmap((void __force __iomem *)vaddr);

__free_pages(page, get_order(size));
--
2.14.4