On Fri, 22 Jan 2010 16:16:19 +0800 Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > > 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 (Am__rico Wang) > > CC: Chen Liqin <liqin.chen@xxxxxxxxxxxxx> > CC: Lennox Wu <lennox.wu@xxxxxxxxx> > CC: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > CC: Am__rico Wang <xiyou.wangcong@xxxxxxxxx> > CC: linux-mips@xxxxxxxxxxxxxx > CC: Yinghai Lu <yinghai@xxxxxxxxxx> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > 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 | 13 +++++++++++++ > 4 files changed, 17 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 16:12:55.000000000 +0800 > @@ -327,6 +327,19 @@ int walk_system_ram_range(unsigned long > > #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; > +} I'll switch this to use __weak. > /* > * 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); Is it appropriate that this function be declared in ioport.h? It's a pretty general function. Dunno. > #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; hm, so we lose the __init.