Subject: [PATCH 1/2] mm/arch: use __free_reserved_page() to simplify the code

From: Xishi Qiu <[email-masked]>
Date: Wed, 4 Sep 2013 18:41:35 +0800

Use __free_reserved_page() to simplify the code in arch.

It used split_page() in consistent_alloc()/__dma_alloc_coherent()/dma_alloc_coherent(),
so page->_count == 1, and we can free it safely.

__free_reserved_page()
	ClearPageReserved()
	init_page_count()  // it won't change the value
	__free_page()

Signed-off-by: Xishi Qiu <[email-masked]>
---
 arch/metag/kernel/dma.c           |    4 +---
 arch/microblaze/mm/consistent.c   |    7 ++-----
 arch/powerpc/mm/dma-noncoherent.c |    4 +---
 3 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c
index 8c00ded..db589ad 100644
--- a/arch/metag/kernel/dma.c
+++ b/arch/metag/kernel/dma.c
@@ -305,9 +305,7 @@ void dma_free_coherent(struct device *dev, size_t size,
 
 			if (pfn_valid(pfn)) {
 				struct page *page = pfn_to_page(pfn);
-				ClearPageReserved(page);
-
-				__free_page(page);
+				__free_reserved_page(page);
 				continue;
 			}
 		}
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
index 5226b09..dbbf224 100644
--- a/arch/microblaze/mm/consistent.c
+++ b/arch/microblaze/mm/consistent.c
@@ -176,8 +176,7 @@ void consistent_free(size_t size, void *vaddr)
 	page = virt_to_page(vaddr);
 
 	do {
-		ClearPageReserved(page);
-		__free_page(page);
+		__free_reserved_page(page);
 		page++;
 	} while (size -= PAGE_SIZE);
 #else
@@ -194,9 +193,7 @@ void consistent_free(size_t size, void *vaddr)
 			pte_clear(&init_mm, (unsigned int)vaddr, ptep);
 			if (pfn_valid(pfn)) {
 				page = pfn_to_page(pfn);
-
-				ClearPageReserved(page);
-				__free_page(page);
+				__free_reserved_page(page);
 			}
 		}
 		vaddr += PAGE_SIZE;
diff --git a/arch/powerpc/mm/dma-noncoherent.c b/arch/powerpc/mm/dma-noncoherent.c
index 6747eec..7b6c107 100644
--- a/arch/powerpc/mm/dma-noncoherent.c
+++ b/arch/powerpc/mm/dma-noncoherent.c
@@ -287,9 +287,7 @@ void __dma_free_coherent(size_t size, void *vaddr)
 			pte_clear(&init_mm, addr, ptep);
 			if (pfn_valid(pfn)) {
 				struct page *page = pfn_to_page(pfn);
-
-				ClearPageReserved(page);
-				__free_page(page);
+				__free_reserved_page(page);
 			}
 		}
 		addr += PAGE_SIZE;
-- 
1.7.1