x86-32, NUMA: implement temporary NUMA init shims

To help transition to common NUMA init, implement temporary 32bit
shims for numa_add_memblk() and numa_set_distance().
numa_add_memblk() registers the memblk and adjusts
node_start/end_pfn[].  numa_set_distance() is noop.

These shims will allow using 64bit NUMA init functions on 32bit and
gradual transition to common NUMA init path.

For detailed description, please read description of commits which
make use of the shim functions.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

arch/x86/include/asm/numa.h

@@ -21,6 +21,9 @@
 extern s16 __apicid_to_node[MAX_LOCAL_APIC];
 extern nodemask_t numa_nodes_parsed __initdata;
 
+extern int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+extern void __init numa_set_distance(int from, int to, int distance);
+
 static inline void set_apicid_to_node(int apicid, s16 node)
 {
 	__apicid_to_node[apicid] = node;

arch/x86/include/asm/numa_64.h

@@ -15,9 +15,6 @@ extern unsigned long numa_free_all_bootmem(void);
  */
 #define NODE_MIN_SIZE (4*1024*1024)
 
-extern int __init numa_add_memblk(int nodeid, u64 start, u64 end);
-extern void __init numa_set_distance(int from, int to, int distance);
-
 #ifdef CONFIG_NUMA_EMU
 #define FAKE_NODE_MIN_SIZE	((u64)32 << 20)
 #define FAKE_NODE_MIN_HASH_MASK	(~(FAKE_NODE_MIN_SIZE - 1UL))

arch/x86/mm/numa_32.c

@@ -414,3 +414,37 @@ int memory_add_physaddr_to_nid(u64 addr)
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 
+/* temporary shim, will go away soon */
+int __init numa_add_memblk(int nid, u64 start, u64 end)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long end_pfn = end >> PAGE_SHIFT;
+
+	printk(KERN_DEBUG "nid %d start_pfn %08lx end_pfn %08lx\n",
+	       nid, start_pfn, end_pfn);
+
+	if (start >= (u64)max_pfn << PAGE_SHIFT) {
+		printk(KERN_INFO "Ignoring SRAT pfns: %08lx - %08lx\n",
+		       start_pfn, end_pfn);
+		return 0;
+	}
+
+	node_set_online(nid);
+	memblock_x86_register_active_regions(nid, start_pfn,
+					     min(end_pfn, max_pfn));
+
+	if (!node_has_online_mem(nid)) {
+		node_start_pfn[nid] = start_pfn;
+		node_end_pfn[nid] = end_pfn;
+	} else {
+		node_start_pfn[nid] = min(node_start_pfn[nid], start_pfn);
+		node_end_pfn[nid] = max(node_end_pfn[nid], end_pfn);
+	}
+	return 0;
+}
+
+/* temporary shim, will go away soon */
+void __init numa_set_distance(int from, int to, int distance)
+{
+	/* nada */
+}