powerpc: Add memory_hotplug_max()
Add a function to get the maximum address that can be hotplug added.
This is needed to calculate the size of the tce table needed to cover
all memory in 1:1 mode.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 74505b2..8c0944c 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1247,4 +1247,30 @@
return nid;
}
+static u64 hot_add_drconf_memory_max(void)
+{
+ struct device_node *memory = NULL;
+ unsigned int drconf_cell_cnt = 0;
+ u64 lmb_size = 0;
+ const u32 *dm = 0;
+
+ memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+ if (memory) {
+ drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
+ lmb_size = of_get_lmb_size(memory);
+ of_node_put(memory);
+ }
+ return lmb_size * drconf_cell_cnt;
+}
+
+/*
+ * memory_hotplug_max - return max address of memory that may be added
+ *
+ * This is currently only used on systems that support drconfig memory
+ * hotplug.
+ */
+u64 memory_hotplug_max(void)
+{
+ return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
+}
#endif /* CONFIG_MEMORY_HOTPLUG */