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authorBadari Pulavarty <pbadari@us.ibm.com>2008-02-05 00:10:18 -0800
committerPaul Mackerras <paulus@samba.org>2008-02-08 19:52:48 +1100
commita99824f327c748b2753f4fa570eb1fefcd6a9c4d (patch)
tree47c6df061ade21ce7ebae43b31a39e882c90cf2b /arch/powerpc
parent1482471d19e77d794012dbacaa65c44ceaae37bb (diff)
[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc
walk_memory_resource() verifies if there are holes in a given memory range, by checking against /proc/iomem. On x86/ia64 system memory is represented in /proc/iomem. On powerpc, we don't show system memory as IO resource in /proc/iomem - instead it's maintained in /proc/device-tree. This provides a way for an architecture to provide its own walk_memory_resource() function. On powerpc, the memory region is small (16MB), contiguous and non-overlapping. So extra checking against the device-tree is not needed. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@gate.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/Kconfig3
-rw-r--r--arch/powerpc/mm/mem.c17
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d55063c021d5..26b963c33c88 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -272,6 +272,9 @@ config HOTPLUG_CPU
config ARCH_ENABLE_MEMORY_HOTPLUG
def_bool y
+config ARCH_HAS_WALK_MEMORY
+ def_bool y
+
config ARCH_ENABLE_MEMORY_HOTREMOVE
def_bool y
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index f0a1fd268b7a..be5c506779a7 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -145,6 +145,23 @@ out:
return ret;
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+/*
+ * walk_memory_resource() needs to make sure there is no holes in a given
+ * memory range. On PPC64, since this range comes from /sysfs, the range
+ * is guaranteed to be valid, non-overlapping and can not contain any
+ * holes. By the time we get here (memory add or remove), /proc/device-tree
+ * is updated and correct. Only reason we need to check against device-tree
+ * would be if we allow user-land to specify a memory range through a
+ * system call/ioctl etc. instead of doing offline/online through /sysfs.
+ */
+int
+walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
+ int (*func)(unsigned long, unsigned long, void *))
+{
+ return (*func)(start_pfn, nr_pages, arg);
+}
+
#endif /* CONFIG_MEMORY_HOTPLUG */
void show_mem(void)