mm: cleanup to make remove_memory() arch-neutral

There is nothing architecture specific about remove_memory().
remove_memory() function is common for all architectures which support
hotplug memory remove.  Instead of duplicating it in every architecture,
collapse them into arch neutral function.

[akpm@linux-foundation.org: fix the export]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 11 insertions, 46 deletions

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index f482a9098e32..054bcd9439aa 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -700,23 +700,6 @@ int arch_add_memory(int nid, u64 start, u64 size)
 
         return ret;
 }
-#ifdef CONFIG_MEMORY_HOTREMOVE
-int remove_memory(u64 start, u64 size)
-{
-        unsigned long start_pfn, end_pfn;
-        unsigned long timeout = 120 * HZ;
-        int ret;
-        start_pfn = start >> PAGE_SHIFT;
-        end_pfn = start_pfn + (size >> PAGE_SHIFT);
-        ret = offline_pages(start_pfn, end_pfn, timeout);
-        if (ret)
-                goto out;
-        /* we can free mem_map at this point */
-out:
-        return ret;
-}
-EXPORT_SYMBOL_GPL(remove_memory);
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 #endif
 
 /*
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 98d7bf99533a..b9e1a1da6e52 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -134,23 +134,6 @@ int arch_add_memory(int nid, u64 start, u64 size)
 
         return __add_pages(zone, start_pfn, nr_pages);
 }
-
-#ifdef CONFIG_MEMORY_HOTREMOVE
-int remove_memory(u64 start, u64 size)
-{
-        unsigned long start_pfn, end_pfn;
-        int ret;
-
-        start_pfn = start >> PAGE_SHIFT;
-        end_pfn = start_pfn + (size >> PAGE_SHIFT);
-        ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
-        if (ret)
-                goto out;
-        /* Arch-specific calls go here - next patch */
-out:
-        return ret;
-}
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
 /*
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 1169130a97ef..158b0d6d7046 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -189,14 +189,3 @@ int arch_add_memory(int nid, u64 start, u64 size)
         return rc;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
-
-#ifdef CONFIG_MEMORY_HOTREMOVE
-int remove_memory(u64 start, u64 size)
-{
-        unsigned long start_pfn, end_pfn;
-
-        start_pfn = PFN_DOWN(start);
-        end_pfn = start_pfn + PFN_DOWN(size);
-        return offline_pages(start_pfn, end_pfn, 120 * HZ);
-}
-#endif /* CONFIG_MEMORY_HOTREMOVE */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 89fee2dcb039..c299d083d8e2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -26,6 +26,7 @@
 #include <linux/delay.h>
 #include <linux/migrate.h>
 #include <linux/page-isolation.h>
+#include <linux/pfn.h>
 
 #include <asm/tlbflush.h>
 
@@ -849,10 +850,19 @@ failed_removal:
 
         return ret;
 }
+
+int remove_memory(u64 start, u64 size)
+{
+        unsigned long start_pfn, end_pfn;
+
+        start_pfn = PFN_DOWN(start);
+        end_pfn = start_pfn + PFN_DOWN(size);
+        return offline_pages(start_pfn, end_pfn, 120 * HZ);
+}
 #else
 int remove_memory(u64 start, u64 size)
 {
         return -EINVAL;
 }
-EXPORT_SYMBOL_GPL(remove_memory);
 #endif /* CONFIG_MEMORY_HOTREMOVE */
+EXPORT_SYMBOL_GPL(remove_memory);