On Fri, Jan 22, 2010 at 06:10:17AM +0200, KAMEZAWA Hiroyuki wrote:
> On Fri, 22 Jan 2010 11:21:03 +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.
> >
> > CC: Chen Liqin <liqin.chen@xxxxxxxxxxxxx>
> > CC: Lennox Wu <lennox.wu@xxxxxxxxx>
> > CC: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> > CC: Am辿rico 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>
>
> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>
> Maybe adding comment like this is good for reviewers..
>
> "This page_is_ram() returns true if specified address is registered
> as System RAM in io_resource list."
>
> AFAIK, this "System RAM" information has been used for kdump to grab valid
> memory area and seems good for the kernel itself.
Thanks! Patch updated as follows.
---
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.
v3: add comment (KAMEZAWA Hiroyuki)
v2: add PAGE_IS_RAM macro (Américo Wang)
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: 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 | 15 +++++++++++++++
4 files changed, 19 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 12:17:50.000000000 +0800
@@ -327,6 +327,21 @@ 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;
+}
+/*
+ * 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 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;
