x86-32, numa: Calculate remap size in common code

Only pgdat and memmap use remap area and there isn't much benefit in
allowing per-node override.  In addition, the use of node_remap_size[]
is confusing in that it contains number of bytes before remap
initialization and then number of pages afterwards.

Move remap size calculation for memap from specific NUMA config
implementations to init_alloc_remap() and make node_remap_size[]
static.

The only behavior difference is that, before this patch, numaq_32
didn't consider max_pfn when calculating the memmap size but it's
enforced after this patch, which is the right thing to do.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1301955840-7246-8-git-send-email-tj@kernel.org
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/topology.h

@@ -95,7 +95,6 @@ extern void setup_node_to_cpumask_map(void);
 #ifdef CONFIG_X86_32
 extern unsigned long node_start_pfn[];
 extern unsigned long node_end_pfn[];
-extern unsigned long node_remap_size[];
 #define node_has_online_mem(nid) (node_start_pfn[nid] != node_end_pfn[nid])
 
 # define SD_CACHE_NICE_TRIES	1

arch/x86/kernel/apic/numaq_32.c

@@ -93,10 +93,6 @@ static inline void numaq_register_node(int node, struct sys_cfg_data *scd)
 						node_end_pfn[node]);
 
 	memory_present(node, node_start_pfn[node], node_end_pfn[node]);
-
-	node_remap_size[node] = node_memmap_size_bytes(node,
-					node_start_pfn[node],
-					node_end_pfn[node]);
 }
 
 /*

arch/x86/mm/numa_32.c

@@ -104,7 +104,7 @@ extern unsigned long highend_pfn, highstart_pfn;
 
 #define LARGE_PAGE_BYTES (PTRS_PER_PTE * PAGE_SIZE)
 
-unsigned long node_remap_size[MAX_NUMNODES];
+static unsigned long node_remap_size[MAX_NUMNODES];
 static void *node_remap_start_vaddr[MAX_NUMNODES];
 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
 
@@ -129,7 +129,6 @@ int __init get_memcfg_numa_flat(void)
 	node_end_pfn[0] = max_pfn;
 	memblock_x86_register_active_regions(0, 0, max_pfn);
 	memory_present(0, 0, max_pfn);
-	node_remap_size[0] = node_memmap_size_bytes(0, 0, max_pfn);
 
         /* Indicate there is one node available. */
 	nodes_clear(node_online_map);
@@ -282,11 +281,10 @@ static __init unsigned long init_alloc_remap(int nid, unsigned long offset)
 	if (node_end_pfn[nid] > max_pfn)
 		node_end_pfn[nid] = max_pfn;
 
-	/* ensure the remap includes space for the pgdat. */
-	size = node_remap_size[nid];
+	/* calculate the necessary space aligned to large page size */
+	size = node_memmap_size_bytes(nid, node_start_pfn[nid],
+				      min(node_end_pfn[nid], max_pfn));
 	size += ALIGN(sizeof(pg_data_t), PAGE_SIZE);
-
-	/* align to large page */
 	size = ALIGN(size, LARGE_PAGE_BYTES);
 
 	node_pa = memblock_find_in_range(node_start_pfn[nid] << PAGE_SHIFT,

arch/x86/mm/srat_32.c

@@ -276,7 +276,6 @@ int __init get_memcfg_from_srat(void)
 		unsigned long end = min(node_end_pfn[nid], max_pfn);
 
 		memory_present(nid, start, end);
-		node_remap_size[nid] = node_memmap_size_bytes(nid, start, end);
 	}
 	return 1;
 out_fail: