From 61ef2489dbf587258526cfd4ebf4bba3b079f401 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Fri, 22 Jan 2010 16:16:19 +0800 Subject: resources: introduce generic page_is_ram() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Lennox Wu Cc: Américo Wang Cc: linux-mips@linux-mips.org Cc: Yinghai Lu Acked-by: Ralf Baechle Reviewed-by: KAMEZAWA Hiroyuki Signed-off-by: Wu Fengguang LKML-Reference: <20100122081619.GA6431@localhost> Cc: Andrew Morton Signed-off-by: H. Peter Anvin --- 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(-) diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 15aa1902a78..4d72aabe835 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -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; diff --git a/arch/score/mm/init.c b/arch/score/mm/init.c index 4e3dcd0c471..f684a590c21 100644 --- a/arch/score/mm/init.c +++ b/arch/score/mm/init.c @@ -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; diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 83aa81297ea..11ef7952b63 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -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 */ diff --git a/kernel/resource.c b/kernel/resource.c index fb11a58b959..b4d637a5525 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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. */ -- cgit v1.2.3-70-g09d2