sh: split coherent pages

Split pages returned by dma_alloc_coherent() and make sure
we free them one by one.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 9f8ea3ada4db..edcd5fbf9651 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -42,6 +42,8 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
                 return NULL;
         }
 
+        split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
+
         *dma_handle = virt_to_phys(ret);
         return ret_nocache;
 }
@@ -51,10 +53,13 @@ void dma_free_coherent(struct device *dev, size_t size,
                          void *vaddr, dma_addr_t dma_handle)
 {
         int order = get_order(size);
+        unsigned long pfn = dma_handle >> PAGE_SHIFT;
+        int k;
 
         if (!dma_release_from_coherent(dev, order, vaddr)) {
                 WARN_ON(irqs_disabled());       /* for portability */
-                free_pages((unsigned long)phys_to_virt(dma_handle), order);
+                for (k = 0; k < (1 << order); k++)
+                        __free_pages(pfn_to_page(pfn + k), 0);
                 iounmap(vaddr);
         }
 }