[PATCH] vmalloc_to_page helper

After William did the remap_pfn_range change, a very common pattern became:
	page = page_to_pfn(vmalloc_to_page((void *)pos));
	if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) {

the patch below adds a very simple helper, vmalloc_to_pfn() to simplify this
a bit.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 16 insertions, 0 deletions

diff --git a/mm/memory.c b/mm/memory.c
index e5c68a782442bb..2f2ba8b1b03278 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1805,6 +1805,16 @@ struct page * vmalloc_to_page(void * vmalloc_addr)
 
 EXPORT_SYMBOL(vmalloc_to_page);
 
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(void * vmalloc_addr)
+{
+	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
 #if !defined(CONFIG_ARCH_GATE_AREA)
 
 #if defined(AT_SYSINFO_EHDR)
diff --git a/mm/nommu.c b/mm/nommu.c
index c99c32fd30d11e..1e780d5c58127a 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -144,6 +144,12 @@ struct page * vmalloc_to_page(void *addr)
 	return virt_to_page(addr);
 }
 
+unsigned long vmalloc_to_pfn(void *addr)
+{
+	return page_to_pfn(virt_to_page(addr));
+}
+
+
 long vread(char *buf, char *addr, unsigned long count)
 {
 	memcpy(buf, addr, count);