mm/arch: use __free_reserved_page() to simplify the code

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 <qiuxishi@huawei.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 4 insertions, 11 deletions

diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c
index 8c00dedadc54..db589ad5dbc4 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 5226b09cbbb2..dbbf2246a260 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 6747eece84af..7b6c10750179 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;