[PATCH] hot-add-mem x86_64: Enable SPARSEMEM in srat.c

Enable x86_64 srat.c to share code between both reserve and sparsemem based
add memory paths.  Both paths need the hot-add area node locality infomration
(nodes_add).  This code refactors the code path to allow this.
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/mm/srat.c

@@ -23,12 +23,6 @@
 
 int acpi_numa __initdata;
 
-#if (defined(CONFIG_ACPI_HOTPLUG_MEMORY) || \
-	defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)) \
-		&& !defined(CONFIG_MEMORY_HOTPLUG)
-#define RESERVE_HOTADD 1
-#endif
-
 static struct acpi_table_slit *acpi_slit;
 
 static nodemask_t nodes_parsed __initdata;
@@ -36,9 +30,6 @@ static struct bootnode nodes[MAX_NUMNODES] __initdata;
 static struct bootnode nodes_add[MAX_NUMNODES] __initdata;
 static int found_add_area __initdata;
 int hotadd_percent __initdata = 0;
-#ifndef RESERVE_HOTADD
-#define hotadd_percent 0	/* Ignore all settings */
-#endif
 
 /* Too small nodes confuse the VM badly. Usually they result
    from BIOS bugs. */
@@ -160,7 +151,7 @@ acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
 	       pxm, pa->apic_id, node);
 }
 
-#ifdef RESERVE_HOTADD
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
 /*
  * Protect against too large hotadd areas that would fill up memory.
  */
@@ -203,15 +194,37 @@ static int hotadd_enough_memory(struct bootnode *nd)
 	return 1;
 }
 
+static int update_end_of_memory(unsigned long end)
+{
+	found_add_area = 1;
+	if ((end >> PAGE_SHIFT) > end_pfn)
+		end_pfn = end >> PAGE_SHIFT;
+	return 1;
+}
+
+static inline int save_add_info(void)
+{
+	return hotadd_percent > 0;
+}
+#else
+int update_end_of_memory(unsigned long end) {return 0;}
+static int hotadd_enough_memory(struct bootnode *nd) {return 1;}
+#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
+static inline int save_add_info(void) {return 1;}
+#else
+static inline int save_add_info(void) {return 0;}
+#endif
+#endif
 /*
- * It is fine to add this area to the nodes data it will be used later
+ * Update nodes_add and decide if to include add are in the zone.
+ * Both SPARSE and RESERVE need nodes_add infomation.
  * This code supports one contigious hot add area per node.
  */
 static int reserve_hotadd(int node, unsigned long start, unsigned long end)
 {
 	unsigned long s_pfn = start >> PAGE_SHIFT;
 	unsigned long e_pfn = end >> PAGE_SHIFT;
-	int changed = 0;
+	int ret = 0, changed = 0;
 	struct bootnode *nd = &nodes_add[node];
 
 	/* I had some trouble with strange memory hotadd regions breaking
@@ -240,7 +253,6 @@ static int reserve_hotadd(int node, unsigned long start, unsigned long end)
 
 	/* Looks good */
 
- 	found_add_area = 1;
 	if (nd->start == nd->end) {
  		nd->start = start;
  		nd->end = end;
@@ -258,14 +270,12 @@ static int reserve_hotadd(int node, unsigned long start, unsigned long end)
 			printk(KERN_ERR "SRAT: Hotplug zone not continuous. Partly ignored\n");
  	}
 
- 	if ((nd->end >> PAGE_SHIFT) > end_pfn)
- 		end_pfn = nd->end >> PAGE_SHIFT;
+	ret = update_end_of_memory(nd->end);
 
 	if (changed)
 	 	printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n", nd->start, nd->end);
-	return 0;
+	return ret;
 }
-#endif
 
 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
 void __init
@@ -284,7 +294,7 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 	}
 	if (ma->flags.enabled == 0)
 		return;
- 	if (ma->flags.hot_pluggable && hotadd_percent == 0)
+ 	if (ma->flags.hot_pluggable && !save_add_info())
 		return;
 	start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
 	end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
@@ -327,15 +337,13 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 	push_node_boundaries(node, nd->start >> PAGE_SHIFT,
 						nd->end >> PAGE_SHIFT);
 
-#ifdef RESERVE_HOTADD
- 	if (ma->flags.hot_pluggable && reserve_hotadd(node, start, end) < 0) {
+ 	if (ma->flags.hot_pluggable && !reserve_hotadd(node, start, end) < 0) {
 		/* Ignore hotadd region. Undo damage */
 		printk(KERN_NOTICE "SRAT: Hotplug region ignored\n");
 		*nd = oldnode;
 		if ((nd->start | nd->end) == 0)
 			node_clear(node, nodes_parsed);
 	}
-#endif
 }
 
 /* Sanity check to catch more bad SRATs (they are amazingly common).
@@ -351,7 +359,6 @@ static int nodes_cover_memory(void)
 		unsigned long e = nodes[i].end >> PAGE_SHIFT;
 		pxmram += e - s;
 		pxmram -= absent_pages_in_range(s, e);
-		pxmram -= nodes_add[i].end - nodes_add[i].start;
 		if ((long)pxmram < 0)
 			pxmram = 0;
 	}