[PATCH] pgdat allocation for new node add (get node id by acpi)

This is to find node id from acpi's handle of memory_device in DSDT.  _PXM for
the new node can be found by acpi_get_pxm() by using new memory's handle.  So,
node id can be found by pxm_to_nid_map[].

  This patch becomes simpler than v2 of node hot-add patch.
  Because old add_memory() function doesn't have node id parameter.
  So, kernel must find its handle by physical address via DSDT again.
  But, v3 just give node id to add_memory() now.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/acpi/acpi_memhotplug.c

@@ -215,7 +215,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 {
 	int result, num_enabled = 0;
 	struct acpi_memory_info *info;
-	int node = 0;
+	int node;
 
 	ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 
@@ -228,6 +228,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		return result;
 	}
 
+	node = acpi_get_node(mem_device->handle);
 	/*
 	 * Tell the VM there is more memory here...
 	 * Note: Assume that this function returns zero on success

drivers/acpi/numa.c

@@ -254,5 +254,18 @@ int acpi_get_pxm(acpi_handle h)
 	} while (ACPI_SUCCESS(status));
 	return -1;
 }
-
 EXPORT_SYMBOL(acpi_get_pxm);
+
+int acpi_get_node(acpi_handle *handle)
+{
+	int pxm, node = -1;
+
+	ACPI_FUNCTION_TRACE("acpi_get_node");
+
+	pxm = acpi_get_pxm(handle);
+	if (pxm >= 0)
+		node = acpi_map_pxm_to_node(pxm);
+
+	return_VALUE(node);
+}
+EXPORT_SYMBOL(acpi_get_node);

include/linux/acpi.h

@@ -528,12 +528,18 @@ static inline void acpi_set_cstate_limit(unsigned int new_limit) { return; }
 
 #ifdef CONFIG_ACPI_NUMA
 int acpi_get_pxm(acpi_handle handle);
+int acpi_get_node(acpi_handle *handle);
 #else
 static inline int acpi_get_pxm(acpi_handle handle)
 {
 	return 0;
 }
+static inline int acpi_get_node(acpi_handle *handle)
+{
+	return 0;
+}
 #endif
+extern int acpi_paddr_to_node(u64 start_addr, u64 size);
 
 extern int pnpacpi_disabled;