Commit 8dfcc9ba authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
Browse files

[PATCH] mm: split highorder pages 



Have an explicit mm call to split higher order pages into individual pages.
 Should help to avoid bugs and be more explicit about the code's intention.

Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: default avatarYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 8e7a9aae

arch/arm/mm/consistent.c

+2 −2
Original line number Diff line number Diff line
@@ -223,6 +223,8 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, 
		pte = consistent_pte[idx] + off;

		c->vm_pages = page;



		split_page(page, order);



		/*

		 * Set the "dma handle"

		 */
@@ -231,7 +233,6 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, 
		do {

			BUG_ON(!pte_none(*pte));



			set_page_count(page, 1);

			/*

			 * x86 does not mark the pages reserved...

			 */
@@ -250,7 +251,6 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, 
		 * Free the otherwise unused pages.

		 */

		while (page < end) {

			set_page_count(page, 1);

			__free_page(page);

			page++;

		}

arch/frv/mm/dma-alloc.c

+1 −3
Original line number Diff line number Diff line
@@ -115,9 +115,7 @@ void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle) 
	 */

	if (order > 0) {

		struct page *rpage = virt_to_page(page);



		for (i = 1; i < (1 << order); i++)

			set_page_count(rpage + i, 1);

		split_page(rpage, order);

	}



	err = 0;

arch/mips/mm/init.c

+3 −2
Original line number Diff line number Diff line
@@ -54,7 +54,8 @@ unsigned long empty_zero_page, zero_page_mask; 
 */

unsigned long setup_zero_pages(void)

{

	unsigned long order, size;

	unsigned int order;

	unsigned long size;

	struct page *page;



	if (cpu_has_vce)
@@ -67,9 +68,9 @@ unsigned long setup_zero_pages(void) 
		panic("Oh boy, that early out of memory?");



	page = virt_to_page(empty_zero_page);

	split_page(page, order);

	while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {

		SetPageReserved(page);

		set_page_count(page, 1);

		page++;

	}

arch/ppc/kernel/dma-mapping.c

+2 −2
Original line number Diff line number Diff line
@@ -223,6 +223,8 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) 
		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);

		struct page *end = page + (1 << order);



		split_page(page, order);



		/*

		 * Set the "dma handle"

		 */
@@ -231,7 +233,6 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) 
		do {

			BUG_ON(!pte_none(*pte));



			set_page_count(page, 1);

			SetPageReserved(page);

			set_pte_at(&init_mm, vaddr,

				   pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
@@ -244,7 +245,6 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) 
		 * Free the otherwise unused pages.

		 */

		while (page < end) {

			set_page_count(page, 1);

			__free_page(page);

			page++;

		}

arch/sh/mm/consistent.c

+1 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle) 
	page = alloc_pages(gfp, order);

	if (!page)

		return NULL;

	split_page(page, order);



	ret = page_address(page);

	*handle = virt_to_phys(ret);
@@ -37,8 +38,6 @@ void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle) 
	end  = page + (1 << order);



	while (++page < end) {

		set_page_count(page, 1);



		/* Free any unused pages */

		if (page >= free) {

			__free_page(page);

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