This is a note to let you know that I've just added the patch titled
mm: add PHYS_PFN, use it in __phys_to_pfn()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-add-phys_pfn-use-it-in-__phys_to_pfn.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8f235d1a3eb7198affe7cadf676a10afb8a46a1a Mon Sep 17 00:00:00 2001
From: Chen Gang <xili_gchen_5257@xxxxxxxxxxx>
Date: Thu, 14 Jan 2016 15:18:33 -0800
Subject: mm: add PHYS_PFN, use it in __phys_to_pfn()
From: Chen Gang <xili_gchen_5257@xxxxxxxxxxx>
commit 8f235d1a3eb7198affe7cadf676a10afb8a46a1a upstream.
__phys_to_pfn and __pfn_to_phys are symmetric, PHYS_PFN and PFN_PHYS are
semmetric:
- y = (phys_addr_t)x << PAGE_SHIFT
- y >> PAGE_SHIFT = (phys_add_t)x
- (unsigned long)(y >> PAGE_SHIFT) = x
[akpm@xxxxxxxxxxxxxxxxxxxx: use macro arg name `x']
[arnd@xxxxxxxx: include linux/pfn.h for PHYS_PFN definition]
Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Marcin Nowakowski <marcin.nowakowski@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/memory_model.h | 4 +++-
include/linux/pfn.h | 1 +
2 files changed, 4 insertions(+), 1 deletion(-)
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -1,6 +1,8 @@
#ifndef __ASM_MEMORY_MODEL_H
#define __ASM_MEMORY_MODEL_H
+#include <linux/pfn.h>
+
#ifndef __ASSEMBLY__
#if defined(CONFIG_FLATMEM)
@@ -72,7 +74,7 @@
/*
* Convert a physical address to a Page Frame Number and back
*/
-#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
+#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
#define page_to_pfn __page_to_pfn
--- a/include/linux/pfn.h
+++ b/include/linux/pfn.h
@@ -9,5 +9,6 @@
#define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
#define PFN_PHYS(x) ((phys_addr_t)(x) << PAGE_SHIFT)
+#define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
#endif
Patches currently in stable-queue which might be from xili_gchen_5257@xxxxxxxxxxx are
queue-4.4/mm-add-phys_pfn-use-it-in-__phys_to_pfn.patch