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Commit 61ef2489 authored by Wu Fengguang's avatar Wu Fengguang Committed by H. Peter Anvin
Browse files

resources: introduce generic page_is_ram() 



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.

v4: prefer plain 1 instead of PAGE_IS_RAM (H. Peter Anvin)
v3: add comment (KAMEZAWA Hiroyuki)
    "AFAIK, this "System RAM" information has been used for kdump to
    grab valid memory area and seems good for the kernel itself."
v2: add PAGE_IS_RAM macro (Américo Wang)

Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
LKML-Reference: <20100122081619.GA6431@localhost>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent ccef0864

arch/mips/mm/init.c

+1 −1
Original line number Diff line number Diff line
@@ -294,7 +294,7 @@ void __init fixrange_init(unsigned long start, unsigned long end, 
}



#ifndef CONFIG_NEED_MULTIPLE_NODES

static int __init page_is_ram(unsigned long pagenr)

int page_is_ram(unsigned long pagenr)

{

	int i;

arch/score/mm/init.c

+1 −1
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ static unsigned long setup_zero_page(void) 
}



#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;

include/linux/ioport.h

+2 −0
Original line number Diff line number Diff line
@@ -188,5 +188,7 @@ 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 */

kernel/resource.c

+13 −0
Original line number Diff line number Diff line
@@ -297,6 +297,19 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 


#endif



static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)

{

	return 1;

}

/*

 * This generic page_is_ram() returns true if specified address is

 * registered as "System RAM" in iomem_resource list.

 */

int __attribute__((weak)) page_is_ram(unsigned long pfn)

{

	return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;

}



/*

 * Find empty slot in the resource tree given range and alignment.

 */