arch/arm/mm/init.c - kernel/prism - Git at Google

 /*
  *  linux/arch/arm/mm/init.c
  *
  *  Copyright (C) 1995-2005 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/swap.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mman.h>
 #include <linux/nodemask.h>
 #include <linux/initrd.h>
 #include <linux/sort.h>
 #include <linux/highmem.h>

 #include <asm/mach-types.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
 #include <asm/sizes.h>
 #include <asm/tlb.h>

 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>

 #include "mm.h"

 static unsigned long phys_initrd_start __initdata = 0;
 static unsigned long phys_initrd_size __initdata = 0;

 static void __init early_initrd(char **p)
 {
 	unsigned long start, size;

 	start = memparse(*p, p);
 	if (**p == ',') {
 		size = memparse((*p) + 1, p);

 		phys_initrd_start = start;
 		phys_initrd_size = size;
 	}
 }
 __early_param("initrd=", early_initrd);

 static int __init parse_tag_initrd(const struct tag *tag)
 {
 	printk(KERN_WARNING "ATAG_INITRD is deprecated; "
 		"please update your bootloader.\n");
 	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
 	phys_initrd_size = tag->u.initrd.size;
 	return 0;
 }

 __tagtable(ATAG_INITRD, parse_tag_initrd);

 static int __init parse_tag_initrd2(const struct tag *tag)
 {
 	phys_initrd_start = tag->u.initrd.start;
 	phys_initrd_size = tag->u.initrd.size;
 	return 0;
 }

 __tagtable(ATAG_INITRD2, parse_tag_initrd2);

 /*
  * This keeps memory configuration data used by a couple memory
  * initialization functions, as well as show_mem() for the skipping
  * of holes in the memory map.  It is populated by arm_add_memory().
  */
 struct meminfo meminfo;

 void show_mem(void)
 {
 	int free = 0, total = 0, reserved = 0;
 	int shared = 0, cached = 0, slab = 0, node, i;
 	struct meminfo * mi = &meminfo;

 	printk("Mem-info:\n");
 	show_free_areas();
 	for_each_online_node(node) {
 		pg_data_t *n = NODE_DATA(node);
 		struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;

 		for_each_nodebank (i,mi,node) {
 			struct membank *bank = &mi->bank[i];
 			unsigned int pfn1, pfn2;
 			struct page *page, *end;

 			pfn1 = bank_pfn_start(bank);
 			pfn2 = bank_pfn_end(bank);

 			page = map + pfn1;
 			end  = map + pfn2;

 			do {
 				total++;
 				if (PageReserved(page))
 					reserved++;
 				else if (PageSwapCache(page))
 					cached++;
 				else if (PageSlab(page))
 					slab++;
 				else if (!page_count(page))
 					free++;
 				else
 					shared += page_count(page) - 1;
 				page++;
 			} while (page < end);
 		}
 	}

 	printk("%d pages of RAM\n", total);
 	printk("%d free pages\n", free);
 	printk("%d reserved pages\n", reserved);
 	printk("%d slab pages\n", slab);
 	printk("%d pages shared\n", shared);
 	printk("%d pages swap cached\n", cached);
 }

 static void __init find_node_limits(int node, struct meminfo *mi,
 	unsigned long *min, unsigned long *max_low, unsigned long *max_high)
 {
 	int i;

 	*min = -1UL;
 	*max_low = *max_high = 0;

 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];
 		unsigned long start, end;

 		start = bank_pfn_start(bank);
 		end = bank_pfn_end(bank);

 		if (*min > start)
 			*min = start;
 		if (*max_high < end)
 			*max_high = end;
 		if (bank->highmem)
 			continue;
 		if (*max_low < end)
 			*max_low = end;
 	}
 }

 /*
  * FIXME: We really want to avoid allocating the bootmap bitmap
  * over the top of the initrd.  Hopefully, this is located towards
  * the start of a bank, so if we allocate the bootmap bitmap at
  * the end, we won't clash.
  */
 static unsigned int __init
 find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
 {
 	unsigned int start_pfn, i, bootmap_pfn;

 	start_pfn   = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
 	bootmap_pfn = 0;

 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];
 		unsigned int start, end;

 		start = bank_pfn_start(bank);
 		end   = bank_pfn_end(bank);

 		if (end < start_pfn)
 			continue;

 		if (start < start_pfn)
 			start = start_pfn;

 		if (end <= start)
 			continue;

 		if (end - start >= bootmap_pages) {
 			bootmap_pfn = start;
 			break;
 		}
 	}

 	if (bootmap_pfn == 0)
 		BUG();

 	return bootmap_pfn;
 }

 static int __init check_initrd(struct meminfo *mi)
 {
 	int initrd_node = -2;
 #ifdef CONFIG_BLK_DEV_INITRD
 	unsigned long end = phys_initrd_start + phys_initrd_size;

 	/*
 	 * Make sure that the initrd is within a valid area of
 	 * memory.
 	 */
 	if (phys_initrd_size) {
 		unsigned int i;

 		initrd_node = -1;

 		for (i = 0; i < mi->nr_banks; i++) {
 			struct membank *bank = &mi->bank[i];
 			if (bank_phys_start(bank) <= phys_initrd_start &&
 			    end <= bank_phys_end(bank))
 				initrd_node = bank->node;
 		}
 	}

 	if (initrd_node == -1) {
 		printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
 		       "physical memory - disabling initrd\n",
 		       phys_initrd_start, phys_initrd_size);
 		phys_initrd_start = phys_initrd_size = 0;
 	}
 #endif

 	return initrd_node;
 }

 static inline void map_memory_bank(struct membank *bank)
 {
 #ifdef CONFIG_MMU
 	struct map_desc map;

 	map.pfn = bank_pfn_start(bank);
 	map.virtual = __phys_to_virt(bank_phys_start(bank));
 	map.length = bank_phys_size(bank);
 	map.type = MT_MEMORY;

 	create_mapping(&map);
 #endif
 }

 static void __init bootmem_init_node(int node, struct meminfo *mi,
 	unsigned long start_pfn, unsigned long end_pfn)
 {
 	unsigned long boot_pfn;
 	unsigned int boot_pages;
 	pg_data_t *pgdat;
 	int i;

 	/*
 	 * Map the memory banks for this node.
 	 */
 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];

 		if (!bank->highmem)
 			map_memory_bank(bank);
 	}

 	/*
 	 * Allocate the bootmem bitmap page.
 	 */
 	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
 	boot_pfn = find_bootmap_pfn(node, mi, boot_pages);

 	/*
 	 * Initialise the bootmem allocator for this node, handing the
 	 * memory banks over to bootmem.
 	 */
 	node_set_online(node);
 	pgdat = NODE_DATA(node);
 	init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);

 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];
 		if (!bank->highmem)
 			free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
 	}

 	/*
 	 * Reserve the bootmem bitmap for this node.
 	 */
 	reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
 			     boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
 }

 static void __init bootmem_reserve_initrd(int node)
 {
 #ifdef CONFIG_BLK_DEV_INITRD
 	pg_data_t *pgdat = NODE_DATA(node);
 	int res;

 	res = reserve_bootmem_node(pgdat, phys_initrd_start,
 			     phys_initrd_size, BOOTMEM_EXCLUSIVE);

 	if (res == 0) {
 		initrd_start = __phys_to_virt(phys_initrd_start);
 		initrd_end = initrd_start + phys_initrd_size;
 	} else {
 		printk(KERN_ERR
 			"INITRD: 0x%08lx+0x%08lx overlaps in-use "
 			"memory region - disabling initrd\n",
 			phys_initrd_start, phys_initrd_size);
 	}
 #endif
 }

 static void __init bootmem_free_node(int node, struct meminfo *mi)
 {
 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 	unsigned long min, max_low, max_high;
 	int i;

 	find_node_limits(node, mi, &min, &max_low, &max_high);

 	/*
 	 * initialise the zones within this node.
 	 */
 	memset(zone_size, 0, sizeof(zone_size));

 	/*
 	 * The size of this node has already been determined.  If we need
 	 * to do anything fancy with the allocation of this memory to the
 	 * zones, now is the time to do it.
 	 */
 	zone_size[0] = max_low - min;
 #ifdef CONFIG_HIGHMEM
 	zone_size[ZONE_HIGHMEM] = max_high - max_low;
 #endif

 	/*
 	 * For each bank in this node, calculate the size of the holes.
 	 *  holes = node_size - sum(bank_sizes_in_node)
 	 */
 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
 	for_each_nodebank(i, mi, node) {
 		int idx = 0;
 #ifdef CONFIG_HIGHMEM
 		if (mi->bank[i].highmem)
 			idx = ZONE_HIGHMEM;
 #endif
 		zhole_size[idx] -= bank_pfn_size(&mi->bank[i]);
 	}

 	/*
 	 * Adjust the sizes according to any special requirements for
 	 * this machine type.
 	 */
 	arch_adjust_zones(node, zone_size, zhole_size);

 	free_area_init_node(node, zone_size, min, zhole_size);
 }

 #ifndef CONFIG_SPARSEMEM
 int pfn_valid(unsigned long pfn)
 {
 	struct meminfo *mi = &meminfo;
 	unsigned int left = 0, right = mi->nr_banks;

 	do {
 		unsigned int mid = (right + left) / 2;
 		struct membank *bank = &mi->bank[mid];

 		if (pfn < bank_pfn_start(bank))
 			right = mid;
 		else if (pfn >= bank_pfn_end(bank))
 			left = mid + 1;
 		else
 			return 1;
 	} while (left < right);
 	return 0;
 }
 EXPORT_SYMBOL(pfn_valid);

 static void arm_memory_present(struct meminfo *mi, int node)
 {
 }
 #else
 static void arm_memory_present(struct meminfo *mi, int node)
 {
 	int i;
 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];
 		memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
 	}
 }
 #endif

 static int __init meminfo_cmp(const void *_a, const void *_b)
 {
 	const struct membank *a = _a, *b = _b;
 	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
 	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
 }

 void __init bootmem_init(void)
 {
 	struct meminfo *mi = &meminfo;
 	unsigned long min, max_low, max_high;
 	int node, initrd_node;

 	sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL);

 	/*
 	 * Locate which node contains the ramdisk image, if any.
 	 */
 	initrd_node = check_initrd(mi);

 	max_low = max_high = 0;

 	/*
 	 * Run through each node initialising the bootmem allocator.
 	 */
 	for_each_node(node) {
 		unsigned long node_low, node_high;

 		find_node_limits(node, mi, &min, &node_low, &node_high);

 		if (node_low > max_low)
 			max_low = node_low;
 		if (node_high > max_high)
 			max_high = node_high;

 		/*
 		 * If there is no memory in this node, ignore it.
 		 * (We can't have nodes which have no lowmem)
 		 */
 		if (node_low == 0)
 			continue;

 		bootmem_init_node(node, mi, min, node_low);

 		/*
 		 * Reserve any special node zero regions.
 		 */
 		if (node == 0)
 			reserve_node_zero(NODE_DATA(node));

 		/*
 		 * If the initrd is in this node, reserve its memory.
 		 */
 		if (node == initrd_node)
 			bootmem_reserve_initrd(node);

 		/*
 		 * Sparsemem tries to allocate bootmem in memory_present(),
 		 * so must be done after the fixed reservations
 		 */
 		arm_memory_present(mi, node);
 	}

 	/*
 	 * sparse_init() needs the bootmem allocator up and running.
 	 */
 	sparse_init();

 	/*
 	 * Now free memory in each node - free_area_init_node needs
 	 * the sparse mem_map arrays initialized by sparse_init()
 	 * for memmap_init_zone(), otherwise all PFNs are invalid.
 	 */
 	for_each_node(node)
 		bootmem_free_node(node, mi);

 	high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;

 	/*
 	 * This doesn't seem to be used by the Linux memory manager any
 	 * more, but is used by ll_rw_block.  If we can get rid of it, we
 	 * also get rid of some of the stuff above as well.
 	 *
 	 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
 	 * the system, not the maximum PFN.
 	 */
 	max_low_pfn = max_low - PHYS_PFN_OFFSET;
 	max_pfn = max_high - PHYS_PFN_OFFSET;
 }

 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
 {
 	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);

 	for (; pfn < end; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 		ClearPageReserved(page);
 		init_page_count(page);
 		__free_page(page);
 		pages++;
 	}

 	if (size && s)
 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);

 	return pages;
 }

 static inline void
 free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
 {
 	struct page *start_pg, *end_pg;
 	unsigned long pg, pgend;

 	/*
 	 * Convert start_pfn/end_pfn to a struct page pointer.
 	 */
 	start_pg = pfn_to_page(start_pfn - 1) + 1;
 	end_pg = pfn_to_page(end_pfn);

 	/*
 	 * Convert to physical addresses, and
 	 * round start upwards and end downwards.
 	 */
 	pg = PAGE_ALIGN(__pa(start_pg));
 	pgend = __pa(end_pg) & PAGE_MASK;

 	/*
 	 * If there are free pages between these,
 	 * free the section of the memmap array.
 	 */
 	if (pg < pgend)
 		free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
 }

 /*
  * The mem_map array can get very big.  Free the unused area of the memory map.
  */
 static void __init free_unused_memmap_node(int node, struct meminfo *mi)
 {
 	unsigned long bank_start, prev_bank_end = 0;
 	unsigned int i;

 	/*
 	 * [FIXME] This relies on each bank being in address order.  This
 	 * may not be the case, especially if the user has provided the
 	 * information on the command line.
 	 */
 	for_each_nodebank(i, mi, node) {
 		struct membank *bank = &mi->bank[i];

 		bank_start = bank_pfn_start(bank);
 		if (bank_start < prev_bank_end) {
 			printk(KERN_ERR "MEM: unordered memory banks.  "
 				"Not freeing memmap.\n");
 			break;
 		}

 		/*
 		 * If we had a previous bank, and there is a space
 		 * between the current bank and the previous, free it.
 		 */
 		if (prev_bank_end && prev_bank_end != bank_start)
 			free_memmap(node, prev_bank_end, bank_start);

 		prev_bank_end = bank_pfn_end(bank);
 	}
 }

 /*
  * mem_init() marks the free areas in the mem_map and tells us how much
  * memory is free.  This is done after various parts of the system have
  * claimed their memory after the kernel image.
  */
 void __init mem_init(void)
 {
 	unsigned int codesize, datasize, initsize;
 	int i, node;

 #ifndef CONFIG_DISCONTIGMEM
 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 #endif

 	/* this will put all unused low memory onto the freelists */
 	for_each_online_node(node) {
 		pg_data_t *pgdat = NODE_DATA(node);

 		free_unused_memmap_node(node, &meminfo);

 		if (pgdat->node_spanned_pages != 0)
 			totalram_pages += free_all_bootmem_node(pgdat);
 	}

 #ifdef CONFIG_SA1111
 	/* now that our DMA memory is actually so designated, we can free it */
 	totalram_pages += free_area(PHYS_PFN_OFFSET,
 				    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
 #endif

 #ifdef CONFIG_HIGHMEM
 	/* set highmem page free */
 	for_each_online_node(node) {
 		for_each_nodebank (i, &meminfo, node) {
 			unsigned long start = bank_pfn_start(&meminfo.bank[i]);
 			unsigned long end = bank_pfn_end(&meminfo.bank[i]);
 			if (start >= max_low_pfn + PHYS_PFN_OFFSET)
 				totalhigh_pages += free_area(start, end, NULL);
 		}
 	}
 	totalram_pages += totalhigh_pages;
 #endif

 	/*
 	 * Since our memory may not be contiguous, calculate the
 	 * real number of pages we have in this system
 	 */
 	printk(KERN_INFO "Memory:");
 	num_physpages = 0;
 	for (i = 0; i < meminfo.nr_banks; i++) {
 		num_physpages += bank_pfn_size(&meminfo.bank[i]);
 		printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
 	}
 	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

 	codesize = _etext - _text;
 	datasize = _end - _data;
 	initsize = __init_end - __init_begin;

 	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 		"%dK data, %dK init, %luK highmem)\n",
 		nr_free_pages() << (PAGE_SHIFT-10), codesize >> 10,
 		datasize >> 10, initsize >> 10,
 		(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));

 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 		extern int sysctl_overcommit_memory;
 		/*
 		 * On a machine this small we won't get
 		 * anywhere without overcommit, so turn
 		 * it on by default.
 		 */
 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 	}
 }

 void free_initmem(void)
 {
 #ifdef CONFIG_HAVE_TCM
 	extern char *__tcm_start, *__tcm_end;

 	totalram_pages += free_area(__phys_to_pfn(__pa(__tcm_start)),
 				    __phys_to_pfn(__pa(__tcm_end)),
 				    "TCM link");
 #endif

 	if (!machine_is_integrator() && !machine_is_cintegrator())
 		totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
 					    __phys_to_pfn(__pa(__init_end)),
 					    "init");
 }

 #ifdef CONFIG_BLK_DEV_INITRD

 static int keep_initrd;

 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	if (!keep_initrd)
 		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
 					    __phys_to_pfn(__pa(end)),
 					    "initrd");
 }

 static int __init keepinitrd_setup(char *__unused)
 {
 	keep_initrd = 1;
 	return 1;
 }

 __setup("keepinitrd", keepinitrd_setup);
 #endif
	/*
	* linux/arch/arm/mm/init.c
	*
	* Copyright (C) 1995-2005 Russell King
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/swap.h>
	#include <linux/init.h>
	#include <linux/bootmem.h>
	#include <linux/mman.h>
	#include <linux/nodemask.h>
	#include <linux/initrd.h>
	#include <linux/sort.h>
	#include <linux/highmem.h>

	#include <asm/mach-types.h>
	#include <asm/sections.h>
	#include <asm/setup.h>
	#include <asm/sizes.h>
	#include <asm/tlb.h>

	#include <asm/mach/arch.h>
	#include <asm/mach/map.h>

	#include "mm.h"

	static unsigned long phys_initrd_start __initdata = 0;
	static unsigned long phys_initrd_size __initdata = 0;

	static void __init early_initrd(char **p)
	{
	unsigned long start, size;

	start = memparse(*p, p);
	if (**p == ',') {
	size = memparse((*p) + 1, p);

	phys_initrd_start = start;
	phys_initrd_size = size;
	}
	}
	__early_param("initrd=", early_initrd);

	static int __init parse_tag_initrd(const struct tag *tag)
	{
	printk(KERN_WARNING "ATAG_INITRD is deprecated; "
	"please update your bootloader.\n");
	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
	phys_initrd_size = tag->u.initrd.size;
	return 0;
	}

	__tagtable(ATAG_INITRD, parse_tag_initrd);

	static int __init parse_tag_initrd2(const struct tag *tag)
	{
	phys_initrd_start = tag->u.initrd.start;
	phys_initrd_size = tag->u.initrd.size;
	return 0;
	}

	__tagtable(ATAG_INITRD2, parse_tag_initrd2);

	/*
	* This keeps memory configuration data used by a couple memory
	* initialization functions, as well as show_mem() for the skipping
	* of holes in the memory map. It is populated by arm_add_memory().
	*/
	struct meminfo meminfo;

	void show_mem(void)
	{
	int free = 0, total = 0, reserved = 0;
	int shared = 0, cached = 0, slab = 0, node, i;
	struct meminfo * mi = &meminfo;

	printk("Mem-info:\n");
	show_free_areas();
	for_each_online_node(node) {
	pg_data_t *n = NODE_DATA(node);
	struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;

	for_each_nodebank (i,mi,node) {
	struct membank *bank = &mi->bank[i];
	unsigned int pfn1, pfn2;
	struct page page, end;

	pfn1 = bank_pfn_start(bank);
	pfn2 = bank_pfn_end(bank);

	page = map + pfn1;
	end = map + pfn2;

	do {
	total++;
	if (PageReserved(page))
	reserved++;
	else if (PageSwapCache(page))
	cached++;
	else if (PageSlab(page))
	slab++;
	else if (!page_count(page))
	free++;
	else
	shared += page_count(page) - 1;
	page++;
	} while (page < end);
	}
	}

	printk("%d pages of RAM\n", total);
	printk("%d free pages\n", free);
	printk("%d reserved pages\n", reserved);
	printk("%d slab pages\n", slab);
	printk("%d pages shared\n", shared);
	printk("%d pages swap cached\n", cached);
	}

	static void __init find_node_limits(int node, struct meminfo *mi,
	unsigned long min, unsigned long max_low, unsigned long *max_high)
	{
	int i;

	*min = -1UL;
	max_low = max_high = 0;

	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];
	unsigned long start, end;

	start = bank_pfn_start(bank);
	end = bank_pfn_end(bank);

	if (*min > start)
	*min = start;
	if (*max_high < end)
	*max_high = end;
	if (bank->highmem)
	continue;
	if (*max_low < end)
	*max_low = end;
	}
	}

	/*
	* FIXME: We really want to avoid allocating the bootmap bitmap
	* over the top of the initrd. Hopefully, this is located towards
	* the start of a bank, so if we allocate the bootmap bitmap at
	* the end, we won't clash.
	*/
	static unsigned int __init
	find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
	{
	unsigned int start_pfn, i, bootmap_pfn;

	start_pfn = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
	bootmap_pfn = 0;

	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];
	unsigned int start, end;

	start = bank_pfn_start(bank);
	end = bank_pfn_end(bank);

	if (end < start_pfn)
	continue;

	if (start < start_pfn)
	start = start_pfn;

	if (end <= start)
	continue;

	if (end - start >= bootmap_pages) {
	bootmap_pfn = start;
	break;
	}
	}

	if (bootmap_pfn == 0)
	BUG();

	return bootmap_pfn;
	}

	static int __init check_initrd(struct meminfo *mi)
	{
	int initrd_node = -2;
	#ifdef CONFIG_BLK_DEV_INITRD
	unsigned long end = phys_initrd_start + phys_initrd_size;

	/*
	* Make sure that the initrd is within a valid area of
	* memory.
	*/
	if (phys_initrd_size) {
	unsigned int i;

	initrd_node = -1;

	for (i = 0; i < mi->nr_banks; i++) {
	struct membank *bank = &mi->bank[i];
	if (bank_phys_start(bank) <= phys_initrd_start &&
	end <= bank_phys_end(bank))
	initrd_node = bank->node;
	}
	}

	if (initrd_node == -1) {
	printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
	"physical memory - disabling initrd\n",
	phys_initrd_start, phys_initrd_size);
	phys_initrd_start = phys_initrd_size = 0;
	}
	#endif

	return initrd_node;
	}

	static inline void map_memory_bank(struct membank *bank)
	{
	#ifdef CONFIG_MMU
	struct map_desc map;

	map.pfn = bank_pfn_start(bank);
	map.virtual = __phys_to_virt(bank_phys_start(bank));
	map.length = bank_phys_size(bank);
	map.type = MT_MEMORY;

	create_mapping(&map);
	#endif
	}

	static void __init bootmem_init_node(int node, struct meminfo *mi,
	unsigned long start_pfn, unsigned long end_pfn)
	{
	unsigned long boot_pfn;
	unsigned int boot_pages;
	pg_data_t *pgdat;
	int i;

	/*
	* Map the memory banks for this node.
	*/
	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];

	if (!bank->highmem)
	map_memory_bank(bank);
	}

	/*
	* Allocate the bootmem bitmap page.
	*/
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	boot_pfn = find_bootmap_pfn(node, mi, boot_pages);

	/*
	* Initialise the bootmem allocator for this node, handing the
	* memory banks over to bootmem.
	*/
	node_set_online(node);
	pgdat = NODE_DATA(node);
	init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);

	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];
	if (!bank->highmem)
	free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
	}

	/*
	* Reserve the bootmem bitmap for this node.
	*/
	reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
	boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
	}

	static void __init bootmem_reserve_initrd(int node)
	{
	#ifdef CONFIG_BLK_DEV_INITRD
	pg_data_t *pgdat = NODE_DATA(node);
	int res;

	res = reserve_bootmem_node(pgdat, phys_initrd_start,
	phys_initrd_size, BOOTMEM_EXCLUSIVE);

	if (res == 0) {
	initrd_start = __phys_to_virt(phys_initrd_start);
	initrd_end = initrd_start + phys_initrd_size;
	} else {
	printk(KERN_ERR
	"INITRD: 0x%08lx+0x%08lx overlaps in-use "
	"memory region - disabling initrd\n",
	phys_initrd_start, phys_initrd_size);
	}
	#endif
	}

	static void __init bootmem_free_node(int node, struct meminfo *mi)
	{
	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
	unsigned long min, max_low, max_high;
	int i;

	find_node_limits(node, mi, &min, &max_low, &max_high);

	/*
	* initialise the zones within this node.
	*/
	memset(zone_size, 0, sizeof(zone_size));

	/*
	* The size of this node has already been determined. If we need
	* to do anything fancy with the allocation of this memory to the
	* zones, now is the time to do it.
	*/
	zone_size[0] = max_low - min;
	#ifdef CONFIG_HIGHMEM
	zone_size[ZONE_HIGHMEM] = max_high - max_low;
	#endif

	/*
	* For each bank in this node, calculate the size of the holes.
	* holes = node_size - sum(bank_sizes_in_node)
	*/
	memcpy(zhole_size, zone_size, sizeof(zhole_size));
	for_each_nodebank(i, mi, node) {
	int idx = 0;
	#ifdef CONFIG_HIGHMEM
	if (mi->bank[i].highmem)
	idx = ZONE_HIGHMEM;
	#endif
	zhole_size[idx] -= bank_pfn_size(&mi->bank[i]);
	}

	/*
	* Adjust the sizes according to any special requirements for
	* this machine type.
	*/
	arch_adjust_zones(node, zone_size, zhole_size);

	free_area_init_node(node, zone_size, min, zhole_size);
	}

	#ifndef CONFIG_SPARSEMEM
	int pfn_valid(unsigned long pfn)
	{
	struct meminfo *mi = &meminfo;
	unsigned int left = 0, right = mi->nr_banks;

	do {
	unsigned int mid = (right + left) / 2;
	struct membank *bank = &mi->bank[mid];

	if (pfn < bank_pfn_start(bank))
	right = mid;
	else if (pfn >= bank_pfn_end(bank))
	left = mid + 1;
	else
	return 1;
	} while (left < right);
	return 0;
	}
	EXPORT_SYMBOL(pfn_valid);

	static void arm_memory_present(struct meminfo *mi, int node)
	{
	}
	#else
	static void arm_memory_present(struct meminfo *mi, int node)
	{
	int i;
	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];
	memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
	}
	}
	#endif

	static int __init meminfo_cmp(const void _a, const void _b)
	{
	const struct membank a = _a, b = _b;
	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
	}

	void __init bootmem_init(void)
	{
	struct meminfo *mi = &meminfo;
	unsigned long min, max_low, max_high;
	int node, initrd_node;

	sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL);

	/*
	* Locate which node contains the ramdisk image, if any.
	*/
	initrd_node = check_initrd(mi);

	max_low = max_high = 0;

	/*
	* Run through each node initialising the bootmem allocator.
	*/
	for_each_node(node) {
	unsigned long node_low, node_high;

	find_node_limits(node, mi, &min, &node_low, &node_high);

	if (node_low > max_low)
	max_low = node_low;
	if (node_high > max_high)
	max_high = node_high;

	/*
	* If there is no memory in this node, ignore it.
	* (We can't have nodes which have no lowmem)
	*/
	if (node_low == 0)
	continue;

	bootmem_init_node(node, mi, min, node_low);

	/*
	* Reserve any special node zero regions.
	*/
	if (node == 0)
	reserve_node_zero(NODE_DATA(node));

	/*
	* If the initrd is in this node, reserve its memory.
	*/
	if (node == initrd_node)
	bootmem_reserve_initrd(node);

	/*
	* Sparsemem tries to allocate bootmem in memory_present(),
	* so must be done after the fixed reservations
	*/
	arm_memory_present(mi, node);
	}

	/*
	* sparse_init() needs the bootmem allocator up and running.
	*/
	sparse_init();

	/*
	* Now free memory in each node - free_area_init_node needs
	* the sparse mem_map arrays initialized by sparse_init()
	* for memmap_init_zone(), otherwise all PFNs are invalid.
	*/
	for_each_node(node)
	bootmem_free_node(node, mi);

	high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;

	/*
	* This doesn't seem to be used by the Linux memory manager any
	* more, but is used by ll_rw_block. If we can get rid of it, we
	* also get rid of some of the stuff above as well.
	*
	* Note: max_low_pfn and max_pfn reflect the number of _pages_ in
	* the system, not the maximum PFN.
	*/
	max_low_pfn = max_low - PHYS_PFN_OFFSET;
	max_pfn = max_high - PHYS_PFN_OFFSET;
	}

	static inline int free_area(unsigned long pfn, unsigned long end, char *s)
	{
	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);

	for (; pfn < end; pfn++) {
	struct page *page = pfn_to_page(pfn);
	ClearPageReserved(page);
	init_page_count(page);
	__free_page(page);
	pages++;
	}

	if (size && s)
	printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);

	return pages;
	}

	static inline void
	free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
	{
	struct page start_pg, end_pg;
	unsigned long pg, pgend;

	/*
	* Convert start_pfn/end_pfn to a struct page pointer.
	*/
	start_pg = pfn_to_page(start_pfn - 1) + 1;
	end_pg = pfn_to_page(end_pfn);

	/*
	* Convert to physical addresses, and
	* round start upwards and end downwards.
	*/
	pg = PAGE_ALIGN(__pa(start_pg));
	pgend = __pa(end_pg) & PAGE_MASK;

	/*
	* If there are free pages between these,
	* free the section of the memmap array.
	*/
	if (pg < pgend)
	free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
	}

	/*
	* The mem_map array can get very big. Free the unused area of the memory map.
	*/
	static void __init free_unused_memmap_node(int node, struct meminfo *mi)
	{
	unsigned long bank_start, prev_bank_end = 0;
	unsigned int i;

	/*
	* [FIXME] This relies on each bank being in address order. This
	* may not be the case, especially if the user has provided the
	* information on the command line.
	*/
	for_each_nodebank(i, mi, node) {
	struct membank *bank = &mi->bank[i];

	bank_start = bank_pfn_start(bank);
	if (bank_start < prev_bank_end) {
	printk(KERN_ERR "MEM: unordered memory banks. "
	"Not freeing memmap.\n");
	break;
	}

	/*
	* If we had a previous bank, and there is a space
	* between the current bank and the previous, free it.
	*/
	if (prev_bank_end && prev_bank_end != bank_start)
	free_memmap(node, prev_bank_end, bank_start);

	prev_bank_end = bank_pfn_end(bank);
	}
	}

	/*
	* mem_init() marks the free areas in the mem_map and tells us how much
	* memory is free. This is done after various parts of the system have
	* claimed their memory after the kernel image.
	*/
	void __init mem_init(void)
	{
	unsigned int codesize, datasize, initsize;
	int i, node;

	#ifndef CONFIG_DISCONTIGMEM
	max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
	#endif

	/* this will put all unused low memory onto the freelists */
	for_each_online_node(node) {
	pg_data_t *pgdat = NODE_DATA(node);

	free_unused_memmap_node(node, &meminfo);

	if (pgdat->node_spanned_pages != 0)
	totalram_pages += free_all_bootmem_node(pgdat);
	}

	#ifdef CONFIG_SA1111
	/* now that our DMA memory is actually so designated, we can free it */
	totalram_pages += free_area(PHYS_PFN_OFFSET,
	__phys_to_pfn(__pa(swapper_pg_dir)), NULL);
	#endif

	#ifdef CONFIG_HIGHMEM
	/* set highmem page free */
	for_each_online_node(node) {
	for_each_nodebank (i, &meminfo, node) {
	unsigned long start = bank_pfn_start(&meminfo.bank[i]);
	unsigned long end = bank_pfn_end(&meminfo.bank[i]);
	if (start >= max_low_pfn + PHYS_PFN_OFFSET)
	totalhigh_pages += free_area(start, end, NULL);
	}
	}
	totalram_pages += totalhigh_pages;
	#endif

	/*
	* Since our memory may not be contiguous, calculate the
	* real number of pages we have in this system
	*/
	printk(KERN_INFO "Memory:");
	num_physpages = 0;
	for (i = 0; i < meminfo.nr_banks; i++) {
	num_physpages += bank_pfn_size(&meminfo.bank[i]);
	printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
	}
	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

	codesize = _etext - _text;
	datasize = _end - _data;
	initsize = __init_end - __init_begin;

	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
	"%dK data, %dK init, %luK highmem)\n",
	nr_free_pages() << (PAGE_SHIFT-10), codesize >> 10,
	datasize >> 10, initsize >> 10,
	(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));

	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
	extern int sysctl_overcommit_memory;
	/*
	* On a machine this small we won't get
	* anywhere without overcommit, so turn
	* it on by default.
	*/
	sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
	}
	}

	void free_initmem(void)
	{
	#ifdef CONFIG_HAVE_TCM
	extern char __tcm_start, __tcm_end;

	totalram_pages += free_area(__phys_to_pfn(__pa(__tcm_start)),
	__phys_to_pfn(__pa(__tcm_end)),
	"TCM link");
	#endif

	if (!machine_is_integrator() && !machine_is_cintegrator())
	totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
	__phys_to_pfn(__pa(__init_end)),
	"init");
	}

	#ifdef CONFIG_BLK_DEV_INITRD

	static int keep_initrd;

	void free_initrd_mem(unsigned long start, unsigned long end)
	{
	if (!keep_initrd)
	totalram_pages += free_area(__phys_to_pfn(__pa(start)),
	__phys_to_pfn(__pa(end)),
	"initrd");
	}

	static int __init keepinitrd_setup(char *__unused)
	{
	keep_initrd = 1;
	return 1;
	}

	__setup("keepinitrd", keepinitrd_setup);
	#endif