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| author | Wu Fengguang <fengguang.wu@intel.com> | 2010-01-22 16:16:19 +0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-02-01 16:58:17 -0800 |
| commit | 61ef2489dbf587258526cfd4ebf4bba3b079f401 (patch) | |
| tree | 4806ed052c73d84821d958f306699b2a27da965e /kernel/resource.c | |
| parent | ccef086454d4c97e7b722e9303390207d681cb4c (diff) | |
| download | lwn-61ef2489dbf587258526cfd4ebf4bba3b079f401.tar.gz lwn-61ef2489dbf587258526cfd4ebf4bba3b079f401.zip | |
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: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
LKML-Reference: <20100122081619.GA6431@localhost>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index fb11a58b9594..b4d637a55256 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. */ |