Patch "mm: add PHYS_PFN, use it in __phys_to_pfn()" has been added to the 4.4-stable tree

Patch "mm: add PHYS_PFN, use it in __phys_to_pfn()" has been added to the 4.4-stable tree

[gregkh]

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@vger.kernel.org> know about it.


>From 8f235d1a3eb7198affe7cadf676a10afb8a46a1a Mon Sep 17 00:00:00 2001
From: Chen Gang <xili_gchen_5257@hotmail.com>
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@hotmail.com>

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@linux-foundation.org: use macro arg name `x']
[arnd@arndb.de: include linux/pfn.h for PHYS_PFN definition]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcin Nowakowski <marcin.nowakowski@mips.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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@hotmail.com are

queue-4.4/mm-add-phys_pfn-use-it-in-__phys_to_pfn.patch