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-rw-r--r--include/linux/highmem.h7
-rw-r--r--mm/highmem.c12
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 3a93f73a8acc..52e96204b3e7 100644
--- 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
diff --git a/mm/highmem.c b/mm/highmem.c
index 57d82c6250c3..d517cd16a6eb 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -94,6 +94,18 @@ static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
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;