From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20121228190337.057290720@decadent.org.uk> Date: Fri, 28 Dec 2012 20:04:04 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Mel Gorman , Rik van Riel Subject: [ 034/173] mm: add kmap_to_page() In-Reply-To: <20121228190330.025298996@decadent.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings This is extracted from Mel Gorman's commit 5a178119b0fb ('mm: add support for direct_IO to highmem pages') upstream. Required to backport commit b9cdc88df8e6 ('virtio: 9p: correctly pass physical address to userspace for high pages'). Cc: Mel Gorman Cc: Rik van Riel Cc: Andrew Morton Signed-off-by: Ben Hutchings --- include/linux/highmem.h | 7 +++++++ mm/highmem.c | 12 ++++++++++++ mm/page_io.c | 3 ++- mm/swap.c | 3 +-- 4 files changed, 22 insertions(+), 3 deletions(-) --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -38,10 +38,17 @@ extern unsigned long totalhigh_pages; void kmap_flush_unused(void); +struct page *kmap_to_page(void *addr); + #else /* CONFIG_HIGHMEM */ static inline unsigned int nr_free_highpages(void) { return 0; } +static inline struct page *kmap_to_page(void *addr) +{ + return virt_to_page(addr); +} + #define totalhigh_pages 0UL #ifndef ARCH_HAS_KMAP --- a/mm/highmem.c +++ b/mm/highmem.c @@ -94,6 +94,18 @@ static DECLARE_WAIT_QUEUE_HEAD(pkmap_map do { spin_unlock(&kmap_lock); (void)(flags); } while (0) #endif +struct page *kmap_to_page(void *vaddr) +{ + unsigned long addr = (unsigned long)vaddr; + + if (addr >= PKMAP_ADDR(0) && addr <= PKMAP_ADDR(LAST_PKMAP)) { + int i = (addr - PKMAP_ADDR(0)) >> PAGE_SHIFT; + return pte_page(pkmap_page_table[i]); + } + + return virt_to_page(addr); +} + static void flush_all_zero_pkmaps(void) { int i;