[PATCH] x86: memset the i386 numa pgdats in arch code

The next patch in this series will remove the arch-independent clearing of the
pgdat's.  This first patch removes the i386 dependency on that behavior.

The new i386 function, remapped_pgdat_init() takes care of initializing the
pgdats which are finally mapped after paging_init() is done.  The
zone_sizes_init() call has to occur after the pgdat clearing.

zone_sizes_init() is currently called from the end of paging_init(), because
that's the first place where the pgdats could have been zeroed.  However,
zone_sizes_init() really doesn't have anything to do with paging, and probably
shouldn't be in paging_init().

Moving this call into setup_memory() allows the declaration of
zone_sizes_init() to change files as well, which means a net removal of one
#ifdef.  It also provides a handy place to put the new function, far away from
the paging code that it really has nothing to do with.  Moving files required
only using highend_pfn inside of the HIGHMEM ifdef, but this saves a line of
code anyway.

Fixes from: Yasunori Goto <ygoto@us.fujitsu.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/setup.c

@@ -40,6 +40,7 @@
 #include <linux/efi.h>
 #include <linux/init.h>
 #include <linux/edd.h>
+#include <linux/nodemask.h>
 #include <video/edid.h>
 #include <asm/e820.h>
 #include <asm/mpspec.h>
@@ -1053,8 +1054,29 @@ static unsigned long __init setup_memory(void)
 
 	return max_low_pfn;
 }
+
+void __init zone_sizes_init(void)
+{
+	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
+	unsigned int max_dma, low;
+
+	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
+	low = max_low_pfn;
+
+	if (low < max_dma)
+		zones_size[ZONE_DMA] = low;
+	else {
+		zones_size[ZONE_DMA] = max_dma;
+		zones_size[ZONE_NORMAL] = low - max_dma;
+#ifdef CONFIG_HIGHMEM
+		zones_size[ZONE_HIGHMEM] = highend_pfn - low;
+#endif
+	}
+	free_area_init(zones_size);
+}
 #else
 extern unsigned long setup_memory(void);
+extern void zone_sizes_init(void);
 #endif /* !CONFIG_DISCONTIGMEM */
 
 void __init setup_bootmem_allocator(void)
@@ -1132,6 +1154,24 @@ void __init setup_bootmem_allocator(void)
 #endif
 }
 
+/*
+ * The node 0 pgdat is initialized before all of these because
+ * it's needed for bootmem.  node>0 pgdats have their virtual
+ * space allocated before the pagetables are in place to access
+ * them, so they can't be cleared then.
+ *
+ * This should all compile down to nothing when NUMA is off.
+ */
+void __init remapped_pgdat_init(void)
+{
+	int nid;
+
+	for_each_online_node(nid) {
+		if (nid != 0)
+			memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
+	}
+}
+
 /*
  * Request address space for all standard RAM and ROM resources
  * and also for regions reported as reserved by the e820.
@@ -1438,6 +1478,8 @@ void __init setup_arch(char **cmdline_p)
 	smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
 #endif
 	paging_init();
+	remapped_pgdat_init();
+	zone_sizes_init();
 
 	/*
 	 * NOTE: at this point the bootmem allocator is fully available.

arch/i386/mm/discontig.c

@@ -133,7 +133,6 @@ static void __init allocate_pgdat(int nid)
 	else {
 		NODE_DATA(nid) = (pg_data_t *)(__va(min_low_pfn << PAGE_SHIFT));
 		min_low_pfn += PFN_UP(sizeof(pg_data_t));
-		memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 	}
 }
 
@@ -263,6 +262,7 @@ unsigned long __init setup_memory(void)
 	for_each_online_node(nid)
 		find_max_pfn_node(nid);
 
+	memset(NODE_DATA(0), 0, sizeof(struct pglist_data));
 	NODE_DATA(0)->bdata = &node0_bdata;
 	setup_bootmem_allocator();
 	return max_low_pfn;
@@ -280,8 +280,6 @@ void __init zone_sizes_init(void)
 	for (nid = MAX_NUMNODES - 1; nid >= 0; nid--) {
 		if (!node_online(nid))
 			continue;
-		if (nid)
-			memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 		NODE_DATA(nid)->pgdat_next = pgdat_list;
 		pgdat_list = NODE_DATA(nid);
 	}

arch/i386/mm/init.c

@@ -394,31 +394,6 @@ void zap_low_mappings (void)
 	flush_tlb_all();
 }
 
-#ifndef CONFIG_DISCONTIGMEM
-void __init zone_sizes_init(void)
-{
-	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
-	unsigned int max_dma, high, low;
-	
-	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
-	low = max_low_pfn;
-	high = highend_pfn;
-	
-	if (low < max_dma)
-		zones_size[ZONE_DMA] = low;
-	else {
-		zones_size[ZONE_DMA] = max_dma;
-		zones_size[ZONE_NORMAL] = low - max_dma;
-#ifdef CONFIG_HIGHMEM
-		zones_size[ZONE_HIGHMEM] = high - low;
-#endif
-	}
-	free_area_init(zones_size);	
-}
-#else
-extern void zone_sizes_init(void);
-#endif /* !CONFIG_DISCONTIGMEM */
-
 static int disable_nx __initdata = 0;
 u64 __supported_pte_mask = ~_PAGE_NX;
 
@@ -519,7 +494,6 @@ void __init paging_init(void)
 	__flush_tlb_all();
 
 	kmap_init();
-	zone_sizes_init();
 }
 
 /*