[PATCH 1/3] resources: introduce generic page_is_ram()

[Wu Fengguang <fengguang.wu@xxxxxxxxx>]

It's based on walk_system_ram_range(), for archs that don't have
their own page_is_ram().

The static verions in MIPS and SCORE are also made global.

CC: Chen Liqin <liqin.chen@xxxxxxxxxxxxx>
CC: Lennox Wu <lennox.wu@xxxxxxxxx>
CC: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
CC: Américo Wang <xiyou.wangcong@xxxxxxxxx>
CC: linux-mips@xxxxxxxxxxxxxx
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> 
CC: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
---
 arch/mips/mm/init.c    |    2 +-
 arch/score/mm/init.c   |    2 +-
 include/linux/ioport.h |    2 ++
 kernel/resource.c      |   11 +++++++++++
 4 files changed, 15 insertions(+), 2 deletions(-)

--- linux-mm.orig/kernel/resource.c	2010-01-22 11:20:34.000000000 +0800
+++ linux-mm/kernel/resource.c	2010-01-22 11:20:35.000000000 +0800
@@ -327,6 +327,17 @@ int walk_system_ram_range(unsigned long 
 
 #endif
 
+#define PAGE_IS_RAM	24
+static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+	return PAGE_IS_RAM;
+}
+int __attribute__((weak)) page_is_ram(unsigned long pfn)
+{
+	return PAGE_IS_RAM == walk_system_ram_range(pfn, 1, NULL, __is_ram);
+}
+#undef PAGE_IS_RAM
+
 /*
  * Find empty slot in the resource tree given range and alignment.
  */
--- linux-mm.orig/include/linux/ioport.h	2010-01-22 11:20:34.000000000 +0800
+++ linux-mm/include/linux/ioport.h	2010-01-22 11:20:35.000000000 +0800
@@ -191,5 +191,7 @@ extern int
 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 		void *arg, int (*func)(unsigned long, unsigned long, void *));
 
+extern int page_is_ram(unsigned long pfn);
+
 #endif /* __ASSEMBLY__ */
 #endif	/* _LINUX_IOPORT_H */
--- linux-mm.orig/arch/score/mm/init.c	2010-01-22 11:20:34.000000000 +0800
+++ linux-mm/arch/score/mm/init.c	2010-01-22 11:20:35.000000000 +0800
@@ -59,7 +59,7 @@ static unsigned long setup_zero_page(voi
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
-static int __init page_is_ram(unsigned long pagenr)
+int page_is_ram(unsigned long pagenr)
 {
 	if (pagenr >= min_low_pfn && pagenr < max_low_pfn)
 		return 1;
--- linux-mm.orig/arch/mips/mm/init.c	2010-01-22 11:20:34.000000000 +0800
+++ linux-mm/arch/mips/mm/init.c	2010-01-22 11:20:35.000000000 +0800
@@ -298,7 +298,7 @@ void __init fixrange_init(unsigned long 
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
-static int __init page_is_ram(unsigned long pagenr)
+int page_is_ram(unsigned long pagenr)
 {
 	int i;