arch/x86_64/mm/numa.c - linux/kernel/git/klassert/ipsec - Git at Google

 /*
  * Generic VM initialization for x86-64 NUMA setups.
  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
  */
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mmzone.h>
 #include <linux/ctype.h>
 #include <linux/module.h>
 #include <linux/nodemask.h>

 #include <asm/e820.h>
 #include <asm/proto.h>
 #include <asm/dma.h>
 #include <asm/numa.h>
 #include <asm/acpi.h>

 #ifndef Dprintk
 #define Dprintk(x...)
 #endif

 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
 bootmem_data_t plat_node_bdata[MAX_NUMNODES];

 struct memnode memnode;

 unsigned char cpu_to_node[NR_CPUS] __read_mostly = {
 	[0 ... NR_CPUS-1] = NUMA_NO_NODE
 };
 unsigned char apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
  	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
 };
 cpumask_t node_to_cpumask[MAX_NUMNODES] __read_mostly;

 int numa_off __initdata;


 /*
  * Given a shift value, try to populate memnodemap[]
  * Returns :
  * 1 if OK
  * 0 if memnodmap[] too small (of shift too small)
  * -1 if node overlap or lost ram (shift too big)
  */
 static int __init
 populate_memnodemap(const struct bootnode *nodes, int numnodes, int shift)
 {
 	int i;
 	int res = -1;
 	unsigned long addr, end;

 	if (shift >= 64)
 		return -1;
 	memset(memnodemap, 0xff, sizeof(memnodemap));
 	for (i = 0; i < numnodes; i++) {
 		addr = nodes[i].start;
 		end = nodes[i].end;
 		if (addr >= end)
 			continue;
 		if ((end >> shift) >= NODEMAPSIZE)
 			return 0;
 		do {
 			if (memnodemap[addr >> shift] != 0xff)
 				return -1;
 			memnodemap[addr >> shift] = i;
                        addr += (1UL << shift);
 		} while (addr < end);
 		res = 1;
 	}
 	return res;
 }

 int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
 {
 	int shift = 20;

 	while (populate_memnodemap(nodes, numnodes, shift + 1) >= 0)
 		shift++;

 	printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
 		shift);

 	if (populate_memnodemap(nodes, numnodes, shift) != 1) {
 		printk(KERN_INFO
 	"Your memory is not aligned you need to rebuild your kernel "
 	"with a bigger NODEMAPSIZE shift=%d\n",
 			shift);
 		return -1;
 	}
 	return shift;
 }

 #ifdef CONFIG_SPARSEMEM
 int early_pfn_to_nid(unsigned long pfn)
 {
 	return phys_to_nid(pfn << PAGE_SHIFT);
 }
 #endif

 static void * __init
 early_node_mem(int nodeid, unsigned long start, unsigned long end,
 	      unsigned long size)
 {
 	unsigned long mem = find_e820_area(start, end, size);
 	void *ptr;
 	if (mem != -1L)
 		return __va(mem);
 	ptr = __alloc_bootmem_nopanic(size,
 				SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS));
 	if (ptr == 0) {
 		printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
 			size, nodeid);
 		return NULL;
 	}
 	return ptr;
 }

 /* Initialize bootmem allocator for a node */
 void __init setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
 {
 	unsigned long start_pfn, end_pfn, bootmap_pages, bootmap_size, bootmap_start;
 	unsigned long nodedata_phys;
 	void *bootmap;
 	const int pgdat_size = round_up(sizeof(pg_data_t), PAGE_SIZE);

 	start = round_up(start, ZONE_ALIGN);

 	printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid, start, end);

 	start_pfn = start >> PAGE_SHIFT;
 	end_pfn = end >> PAGE_SHIFT;

 	node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size);
 	if (node_data[nodeid] == NULL)
 		return;
 	nodedata_phys = __pa(node_data[nodeid]);

 	memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
 	NODE_DATA(nodeid)->bdata = &plat_node_bdata[nodeid];
 	NODE_DATA(nodeid)->node_start_pfn = start_pfn;
 	NODE_DATA(nodeid)->node_spanned_pages = end_pfn - start_pfn;

 	/* Find a place for the bootmem map */
 	bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
 	bootmap_start = round_up(nodedata_phys + pgdat_size, PAGE_SIZE);
 	bootmap = early_node_mem(nodeid, bootmap_start, end,
 					bootmap_pages<<PAGE_SHIFT);
 	if (bootmap == NULL)  {
 		if (nodedata_phys < start || nodedata_phys >= end)
 			free_bootmem((unsigned long)node_data[nodeid],pgdat_size);
 		node_data[nodeid] = NULL;
 		return;
 	}
 	bootmap_start = __pa(bootmap);
 	Dprintk("bootmap start %lu pages %lu\n", bootmap_start, bootmap_pages);

 	bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
 					 bootmap_start >> PAGE_SHIFT,
 					 start_pfn, end_pfn);

 	e820_bootmem_free(NODE_DATA(nodeid), start, end);

 	reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size);
 	reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start, bootmap_pages<<PAGE_SHIFT);
 #ifdef CONFIG_ACPI_NUMA
 	srat_reserve_add_area(nodeid);
 #endif
 	node_set_online(nodeid);
 }

 /* Initialize final allocator for a zone */
 void __init setup_node_zones(int nodeid)
 {
 	unsigned long start_pfn, end_pfn, memmapsize, limit;
 	unsigned long zones[MAX_NR_ZONES];
 	unsigned long holes[MAX_NR_ZONES];

  	start_pfn = node_start_pfn(nodeid);
  	end_pfn = node_end_pfn(nodeid);

 	Dprintk(KERN_INFO "Setting up node %d %lx-%lx\n",
 		nodeid, start_pfn, end_pfn);

 	/* Try to allocate mem_map at end to not fill up precious <4GB
 	   memory. */
 	memmapsize = sizeof(struct page) * (end_pfn-start_pfn);
 	limit = end_pfn << PAGE_SHIFT;
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 	NODE_DATA(nodeid)->node_mem_map =
 		__alloc_bootmem_core(NODE_DATA(nodeid)->bdata,
 				memmapsize, SMP_CACHE_BYTES,
 				round_down(limit - memmapsize, PAGE_SIZE),
 				limit);
 #endif

 	size_zones(zones, holes, start_pfn, end_pfn);
 	free_area_init_node(nodeid, NODE_DATA(nodeid), zones,
 			    start_pfn, holes);
 }

 void __init numa_init_array(void)
 {
 	int rr, i;
 	/* There are unfortunately some poorly designed mainboards around
 	   that only connect memory to a single CPU. This breaks the 1:1 cpu->node
 	   mapping. To avoid this fill in the mapping for all possible
 	   CPUs, as the number of CPUs is not known yet.
 	   We round robin the existing nodes. */
 	rr = first_node(node_online_map);
 	for (i = 0; i < NR_CPUS; i++) {
 		if (cpu_to_node[i] != NUMA_NO_NODE)
 			continue;
  		numa_set_node(i, rr);
 		rr = next_node(rr, node_online_map);
 		if (rr == MAX_NUMNODES)
 			rr = first_node(node_online_map);
 	}

 }

 #ifdef CONFIG_NUMA_EMU
 int numa_fake __initdata = 0;

 /* Numa emulation */
 static int numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
 {
  	int i;
  	struct bootnode nodes[MAX_NUMNODES];
  	unsigned long sz = ((end_pfn - start_pfn)<<PAGE_SHIFT) / numa_fake;

  	/* Kludge needed for the hash function */
  	if (hweight64(sz) > 1) {
  		unsigned long x = 1;
  		while ((x << 1) < sz)
  			x <<= 1;
  		if (x < sz/2)
  			printk(KERN_ERR "Numa emulation unbalanced. Complain to maintainer\n");
  		sz = x;
  	}

  	memset(&nodes,0,sizeof(nodes));
  	for (i = 0; i < numa_fake; i++) {
  		nodes[i].start = (start_pfn<<PAGE_SHIFT) + i*sz;
  		if (i == numa_fake-1)
  			sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start;
  		nodes[i].end = nodes[i].start + sz;
  		printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
  		       i,
  		       nodes[i].start, nodes[i].end,
  		       (nodes[i].end - nodes[i].start) >> 20);
 		node_set_online(i);
  	}
  	memnode_shift = compute_hash_shift(nodes, numa_fake);
  	if (memnode_shift < 0) {
  		memnode_shift = 0;
  		printk(KERN_ERR "No NUMA hash function found. Emulation disabled.\n");
  		return -1;
  	}
  	for_each_online_node(i)
  		setup_node_bootmem(i, nodes[i].start, nodes[i].end);
  	numa_init_array();
  	return 0;
 }
 #endif

 void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 {
 	int i;

 #ifdef CONFIG_NUMA_EMU
 	if (numa_fake && !numa_emulation(start_pfn, end_pfn))
  		return;
 #endif

 #ifdef CONFIG_ACPI_NUMA
 	if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
 					  end_pfn << PAGE_SHIFT))
  		return;
 #endif

 #ifdef CONFIG_K8_NUMA
 	if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT))
 		return;
 #endif
 	printk(KERN_INFO "%s\n",
 	       numa_off ? "NUMA turned off" : "No NUMA configuration found");

 	printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
 	       start_pfn << PAGE_SHIFT,
 	       end_pfn << PAGE_SHIFT);
 		/* setup dummy node covering all memory */
 	memnode_shift = 63;
 	memnodemap[0] = 0;
 	nodes_clear(node_online_map);
 	node_set_online(0);
 	for (i = 0; i < NR_CPUS; i++)
 		numa_set_node(i, 0);
 	node_to_cpumask[0] = cpumask_of_cpu(0);
 	setup_node_bootmem(0, start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
 }

 __cpuinit void numa_add_cpu(int cpu)
 {
 	set_bit(cpu, &node_to_cpumask[cpu_to_node(cpu)]);
 }

 void __cpuinit numa_set_node(int cpu, int node)
 {
 	cpu_pda(cpu)->nodenumber = node;
 	cpu_to_node[cpu] = node;
 }

 unsigned long __init numa_free_all_bootmem(void)
 {
 	int i;
 	unsigned long pages = 0;
 	for_each_online_node(i) {
 		pages += free_all_bootmem_node(NODE_DATA(i));
 	}
 	return pages;
 }

 #ifdef CONFIG_SPARSEMEM
 static void __init arch_sparse_init(void)
 {
 	int i;

 	for_each_online_node(i)
 		memory_present(i, node_start_pfn(i), node_end_pfn(i));

 	sparse_init();
 }
 #else
 #define arch_sparse_init() do {} while (0)
 #endif

 void __init paging_init(void)
 {
 	int i;

 	arch_sparse_init();

 	for_each_online_node(i) {
 		setup_node_zones(i);
 	}
 }

 /* [numa=off] */
 __init int numa_setup(char *opt)
 {
 	if (!strncmp(opt,"off",3))
 		numa_off = 1;
 #ifdef CONFIG_NUMA_EMU
 	if(!strncmp(opt, "fake=", 5)) {
 		numa_fake = simple_strtoul(opt+5,NULL,0); ;
 		if (numa_fake >= MAX_NUMNODES)
 			numa_fake = MAX_NUMNODES;
 	}
 #endif
 #ifdef CONFIG_ACPI_NUMA
  	if (!strncmp(opt,"noacpi",6))
  		acpi_numa = -1;
 	if (!strncmp(opt,"hotadd=", 7))
 		hotadd_percent = simple_strtoul(opt+7, NULL, 10);
 #endif
 	return 1;
 }

 /*
  * Setup early cpu_to_node.
  *
  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
  * and apicid_to_node[] tables have valid entries for a CPU.
  * This means we skip cpu_to_node[] initialisation for NUMA
  * emulation and faking node case (when running a kernel compiled
  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
  * is already initialized in a round robin manner at numa_init_array,
  * prior to this call, and this initialization is good enough
  * for the fake NUMA cases.
  */
 void __init init_cpu_to_node(void)
 {
 	int i;
  	for (i = 0; i < NR_CPUS; i++) {
 		u8 apicid = x86_cpu_to_apicid[i];
 		if (apicid == BAD_APICID)
 			continue;
 		if (apicid_to_node[apicid] == NUMA_NO_NODE)
 			continue;
 		numa_set_node(i,apicid_to_node[apicid]);
 	}
 }

 EXPORT_SYMBOL(cpu_to_node);
 EXPORT_SYMBOL(node_to_cpumask);
 EXPORT_SYMBOL(memnode);
 EXPORT_SYMBOL(node_data);

 #ifdef CONFIG_DISCONTIGMEM
 /*
  * Functions to convert PFNs from/to per node page addresses.
  * These are out of line because they are quite big.
  * They could be all tuned by pre caching more state.
  * Should do that.
  */

 int pfn_valid(unsigned long pfn)
 {
 	unsigned nid;
 	if (pfn >= num_physpages)
 		return 0;
 	nid = pfn_to_nid(pfn);
 	if (nid == 0xff)
 		return 0;
 	return pfn >= node_start_pfn(nid) && (pfn) < node_end_pfn(nid);
 }
 EXPORT_SYMBOL(pfn_valid);
 #endif
	/*
	* Generic VM initialization for x86-64 NUMA setups.
	* Copyright 2002,2003 Andi Kleen, SuSE Labs.
	*/
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/string.h>
	#include <linux/init.h>
	#include <linux/bootmem.h>
	#include <linux/mmzone.h>
	#include <linux/ctype.h>
	#include <linux/module.h>
	#include <linux/nodemask.h>

	#include <asm/e820.h>
	#include <asm/proto.h>
	#include <asm/dma.h>
	#include <asm/numa.h>
	#include <asm/acpi.h>

	#ifndef Dprintk
	#define Dprintk(x...)
	#endif

	struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
	bootmem_data_t plat_node_bdata[MAX_NUMNODES];

	struct memnode memnode;

	unsigned char cpu_to_node[NR_CPUS] __read_mostly = {
	[0 ... NR_CPUS-1] = NUMA_NO_NODE
	};
	unsigned char apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
	};
	cpumask_t node_to_cpumask[MAX_NUMNODES] __read_mostly;

	int numa_off __initdata;


	/*
	* Given a shift value, try to populate memnodemap[]
	* Returns :
	* 1 if OK
	* 0 if memnodmap[] too small (of shift too small)
	* -1 if node overlap or lost ram (shift too big)
	*/
	static int __init
	populate_memnodemap(const struct bootnode *nodes, int numnodes, int shift)
	{
	int i;
	int res = -1;
	unsigned long addr, end;

	if (shift >= 64)
	return -1;
	memset(memnodemap, 0xff, sizeof(memnodemap));
	for (i = 0; i < numnodes; i++) {
	addr = nodes[i].start;
	end = nodes[i].end;
	if (addr >= end)
	continue;
	if ((end >> shift) >= NODEMAPSIZE)
	return 0;
	do {
	if (memnodemap[addr >> shift] != 0xff)
	return -1;
	memnodemap[addr >> shift] = i;
	addr += (1UL << shift);
	} while (addr < end);
	res = 1;
	}
	return res;
	}

	int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
	{
	int shift = 20;

	while (populate_memnodemap(nodes, numnodes, shift + 1) >= 0)
	shift++;

	printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
	shift);

	if (populate_memnodemap(nodes, numnodes, shift) != 1) {
	printk(KERN_INFO
	"Your memory is not aligned you need to rebuild your kernel "
	"with a bigger NODEMAPSIZE shift=%d\n",
	shift);
	return -1;
	}
	return shift;
	}

	#ifdef CONFIG_SPARSEMEM
	int early_pfn_to_nid(unsigned long pfn)
	{
	return phys_to_nid(pfn << PAGE_SHIFT);
	}
	#endif

	static void * __init
	early_node_mem(int nodeid, unsigned long start, unsigned long end,
	unsigned long size)
	{
	unsigned long mem = find_e820_area(start, end, size);
	void *ptr;
	if (mem != -1L)
	return __va(mem);
	ptr = __alloc_bootmem_nopanic(size,
	SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS));
	if (ptr == 0) {
	printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
	size, nodeid);
	return NULL;
	}
	return ptr;
	}

	/* Initialize bootmem allocator for a node */
	void __init setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
	{
	unsigned long start_pfn, end_pfn, bootmap_pages, bootmap_size, bootmap_start;
	unsigned long nodedata_phys;
	void *bootmap;
	const int pgdat_size = round_up(sizeof(pg_data_t), PAGE_SIZE);

	start = round_up(start, ZONE_ALIGN);

	printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid, start, end);

	start_pfn = start >> PAGE_SHIFT;
	end_pfn = end >> PAGE_SHIFT;

	node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size);
	if (node_data[nodeid] == NULL)
	return;
	nodedata_phys = __pa(node_data[nodeid]);

	memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
	NODE_DATA(nodeid)->bdata = &plat_node_bdata[nodeid];
	NODE_DATA(nodeid)->node_start_pfn = start_pfn;
	NODE_DATA(nodeid)->node_spanned_pages = end_pfn - start_pfn;

	/* Find a place for the bootmem map */
	bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	bootmap_start = round_up(nodedata_phys + pgdat_size, PAGE_SIZE);
	bootmap = early_node_mem(nodeid, bootmap_start, end,
	bootmap_pages<<PAGE_SHIFT);
	if (bootmap == NULL) {
	if (nodedata_phys < start \|\| nodedata_phys >= end)
	free_bootmem((unsigned long)node_data[nodeid],pgdat_size);
	node_data[nodeid] = NULL;
	return;
	}
	bootmap_start = __pa(bootmap);
	Dprintk("bootmap start %lu pages %lu\n", bootmap_start, bootmap_pages);

	bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
	bootmap_start >> PAGE_SHIFT,
	start_pfn, end_pfn);

	e820_bootmem_free(NODE_DATA(nodeid), start, end);

	reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size);
	reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start, bootmap_pages<<PAGE_SHIFT);
	#ifdef CONFIG_ACPI_NUMA
	srat_reserve_add_area(nodeid);
	#endif
	node_set_online(nodeid);
	}

	/* Initialize final allocator for a zone */
	void __init setup_node_zones(int nodeid)
	{
	unsigned long start_pfn, end_pfn, memmapsize, limit;
	unsigned long zones[MAX_NR_ZONES];
	unsigned long holes[MAX_NR_ZONES];

	start_pfn = node_start_pfn(nodeid);
	end_pfn = node_end_pfn(nodeid);

	Dprintk(KERN_INFO "Setting up node %d %lx-%lx\n",
	nodeid, start_pfn, end_pfn);

	/* Try to allocate mem_map at end to not fill up precious <4GB
	memory. */
	memmapsize = sizeof(struct page) * (end_pfn-start_pfn);
	limit = end_pfn << PAGE_SHIFT;
	#ifdef CONFIG_FLAT_NODE_MEM_MAP
	NODE_DATA(nodeid)->node_mem_map =
	__alloc_bootmem_core(NODE_DATA(nodeid)->bdata,
	memmapsize, SMP_CACHE_BYTES,
	round_down(limit - memmapsize, PAGE_SIZE),
	limit);
	#endif

	size_zones(zones, holes, start_pfn, end_pfn);
	free_area_init_node(nodeid, NODE_DATA(nodeid), zones,
	start_pfn, holes);
	}

	void __init numa_init_array(void)
	{
	int rr, i;
	/* There are unfortunately some poorly designed mainboards around
	that only connect memory to a single CPU. This breaks the 1:1 cpu->node
	mapping. To avoid this fill in the mapping for all possible
	CPUs, as the number of CPUs is not known yet.
	We round robin the existing nodes. */
	rr = first_node(node_online_map);
	for (i = 0; i < NR_CPUS; i++) {
	if (cpu_to_node[i] != NUMA_NO_NODE)
	continue;
	numa_set_node(i, rr);
	rr = next_node(rr, node_online_map);
	if (rr == MAX_NUMNODES)
	rr = first_node(node_online_map);
	}

	}

	#ifdef CONFIG_NUMA_EMU
	int numa_fake __initdata = 0;

	/* Numa emulation */
	static int numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
	{
	int i;
	struct bootnode nodes[MAX_NUMNODES];
	unsigned long sz = ((end_pfn - start_pfn)<<PAGE_SHIFT) / numa_fake;

	/* Kludge needed for the hash function */
	if (hweight64(sz) > 1) {
	unsigned long x = 1;
	while ((x << 1) < sz)
	x <<= 1;
	if (x < sz/2)
	printk(KERN_ERR "Numa emulation unbalanced. Complain to maintainer\n");
	sz = x;
	}

	memset(&nodes,0,sizeof(nodes));
	for (i = 0; i < numa_fake; i++) {
	nodes[i].start = (start_pfn<<PAGE_SHIFT) + i*sz;
	if (i == numa_fake-1)
	sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start;
	nodes[i].end = nodes[i].start + sz;
	printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
	i,
	nodes[i].start, nodes[i].end,
	(nodes[i].end - nodes[i].start) >> 20);
	node_set_online(i);
	}
	memnode_shift = compute_hash_shift(nodes, numa_fake);
	if (memnode_shift < 0) {
	memnode_shift = 0;
	printk(KERN_ERR "No NUMA hash function found. Emulation disabled.\n");
	return -1;
	}
	for_each_online_node(i)
	setup_node_bootmem(i, nodes[i].start, nodes[i].end);
	numa_init_array();
	return 0;
	}
	#endif

	void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
	{
	int i;

	#ifdef CONFIG_NUMA_EMU
	if (numa_fake && !numa_emulation(start_pfn, end_pfn))
	return;
	#endif

	#ifdef CONFIG_ACPI_NUMA
	if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
	end_pfn << PAGE_SHIFT))
	return;
	#endif

	#ifdef CONFIG_K8_NUMA
	if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT))
	return;
	#endif
	printk(KERN_INFO "%s\n",
	numa_off ? "NUMA turned off" : "No NUMA configuration found");

	printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
	start_pfn << PAGE_SHIFT,
	end_pfn << PAGE_SHIFT);
	/* setup dummy node covering all memory */
	memnode_shift = 63;
	memnodemap[0] = 0;
	nodes_clear(node_online_map);
	node_set_online(0);
	for (i = 0; i < NR_CPUS; i++)
	numa_set_node(i, 0);
	node_to_cpumask[0] = cpumask_of_cpu(0);
	setup_node_bootmem(0, start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
	}

	__cpuinit void numa_add_cpu(int cpu)
	{
	set_bit(cpu, &node_to_cpumask[cpu_to_node(cpu)]);
	}

	void __cpuinit numa_set_node(int cpu, int node)
	{
	cpu_pda(cpu)->nodenumber = node;
	cpu_to_node[cpu] = node;
	}

	unsigned long __init numa_free_all_bootmem(void)
	{
	int i;
	unsigned long pages = 0;
	for_each_online_node(i) {
	pages += free_all_bootmem_node(NODE_DATA(i));
	}
	return pages;
	}

	#ifdef CONFIG_SPARSEMEM
	static void __init arch_sparse_init(void)
	{
	int i;

	for_each_online_node(i)
	memory_present(i, node_start_pfn(i), node_end_pfn(i));

	sparse_init();
	}
	#else
	#define arch_sparse_init() do {} while (0)
	#endif

	void __init paging_init(void)
	{
	int i;

	arch_sparse_init();

	for_each_online_node(i) {
	setup_node_zones(i);
	}
	}

	/* [numa=off] */
	__init int numa_setup(char *opt)
	{
	if (!strncmp(opt,"off",3))
	numa_off = 1;
	#ifdef CONFIG_NUMA_EMU
	if(!strncmp(opt, "fake=", 5)) {
	numa_fake = simple_strtoul(opt+5,NULL,0); ;
	if (numa_fake >= MAX_NUMNODES)
	numa_fake = MAX_NUMNODES;
	}
	#endif
	#ifdef CONFIG_ACPI_NUMA
	if (!strncmp(opt,"noacpi",6))
	acpi_numa = -1;
	if (!strncmp(opt,"hotadd=", 7))
	hotadd_percent = simple_strtoul(opt+7, NULL, 10);
	#endif
	return 1;
	}

	/*
	* Setup early cpu_to_node.
	*
	* Populate cpu_to_node[] only if x86_cpu_to_apicid[],
	* and apicid_to_node[] tables have valid entries for a CPU.
	* This means we skip cpu_to_node[] initialisation for NUMA
	* emulation and faking node case (when running a kernel compiled
	* for NUMA on a non NUMA box), which is OK as cpu_to_node[]
	* is already initialized in a round robin manner at numa_init_array,
	* prior to this call, and this initialization is good enough
	* for the fake NUMA cases.
	*/
	void __init init_cpu_to_node(void)
	{
	int i;
	for (i = 0; i < NR_CPUS; i++) {
	u8 apicid = x86_cpu_to_apicid[i];
	if (apicid == BAD_APICID)
	continue;
	if (apicid_to_node[apicid] == NUMA_NO_NODE)
	continue;
	numa_set_node(i,apicid_to_node[apicid]);
	}
	}

	EXPORT_SYMBOL(cpu_to_node);
	EXPORT_SYMBOL(node_to_cpumask);
	EXPORT_SYMBOL(memnode);
	EXPORT_SYMBOL(node_data);

	#ifdef CONFIG_DISCONTIGMEM
	/*
	* Functions to convert PFNs from/to per node page addresses.
	* These are out of line because they are quite big.
	* They could be all tuned by pre caching more state.
	* Should do that.
	*/

	int pfn_valid(unsigned long pfn)
	{
	unsigned nid;
	if (pfn >= num_physpages)
	return 0;
	nid = pfn_to_nid(pfn);
	if (nid == 0xff)
	return 0;
	return pfn >= node_start_pfn(nid) && (pfn) < node_end_pfn(nid);
	}
	EXPORT_SYMBOL(pfn_valid);
	#endif