memblock: Move memblock arrays to static storage in memblock.c and make their size a variable

This is in preparation for having resizable arrays.

Note that we still allocate one more than needed, this is unchanged from
the previous implementation.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

include/linux/memblock.h

@@ -18,7 +18,7 @@
 
 #include <asm/memblock.h>
 
-#define MAX_MEMBLOCK_REGIONS 128
+#define INIT_MEMBLOCK_REGIONS 128
 
 struct memblock_region {
 	phys_addr_t base;
@@ -26,8 +26,9 @@ struct memblock_region {
 };
 
 struct memblock_type {
-	unsigned long cnt;
-	struct memblock_region regions[MAX_MEMBLOCK_REGIONS+1];
+	unsigned long cnt;	/* number of regions */
+	unsigned long max;	/* size of the allocated array */
+	struct memblock_region *regions;
 };
 
 struct memblock {

mm/memblock.c

@@ -18,6 +18,8 @@
 struct memblock memblock;
 
 static int memblock_debug;
+static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS + 1];
+static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS + 1];
 
 static int __init early_memblock(char *p)
 {
@@ -104,6 +106,12 @@ static void memblock_coalesce_regions(struct memblock_type *type,
 
 void __init memblock_init(void)
 {
+	/* Hookup the initial arrays */
+	memblock.memory.regions	= memblock_memory_init_regions;
+	memblock.memory.max		= INIT_MEMBLOCK_REGIONS;
+	memblock.reserved.regions	= memblock_reserved_init_regions;
+	memblock.reserved.max	= INIT_MEMBLOCK_REGIONS;
+
 	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
 	 * This simplifies the memblock_add() code below...
 	 */
@@ -169,7 +177,7 @@ static long memblock_add_region(struct memblock_type *type, phys_addr_t base, ph
 
 	if (coalesced)
 		return coalesced;
-	if (type->cnt >= MAX_MEMBLOCK_REGIONS)
+	if (type->cnt >= type->max)
 		return -1;
 
 	/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */