powerpc/pseries: Use remove_memory() to remove memory

The memory remove code for powerpc/pseries should call remove_memory()
so that we are holding the hotplug_memory lock during memory remove
operations.

This patch updates the memory node remove handler to call remove_memory()
and adds a ppc_md.remove_memory() entry to handle pseries specific work
that is called from arch_remove_memory().

During memory remove in pseries_remove_memblock() we have to stay with
removing memory one section at a time. This is needed because of how memory
resources are handled. During memory add for pseries (via the probe file in
sysfs) we add memory one section at a time which gives us a memory resource
for each section. Future patches will aim to address this so will not have
to remove memory one section at a time.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 4b5cd5c..2c8e90f 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -139,9 +139,14 @@ int arch_remove_memory(u64 start, u64 size)
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	struct zone *zone;
+	int ret;
 
 	zone = page_zone(pfn_to_page(start_pfn));
-	return __remove_pages(zone, start_pfn, nr_pages);
+	ret = __remove_pages(zone, start_pfn, nr_pages);
+	if (!ret && (ppc_md.remove_memory))
+		ret = ppc_md.remove_memory(start, size);
+
+	return ret;
 }
 #endif
 #endif /* CONFIG_MEMORY_HOTPLUG */