linux/arch/arm/mm/init.c

/*
 *  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/highmem.h>
#include <linux/gfp.h>

#include <asm/mach-types.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/fixmap.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 int __init early_initrd(char *p)
{
	unsigned long start, size;
	char *endp;

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

		phys_initrd_start = start;
		phys_initrd_size = size;
	}
	return 0;
}
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, i;
	struct meminfo * mi = &meminfo;

	printk("Mem-info:\n");
	show_free_areas();

	for_each_bank (i, mi) {
		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 = pfn_to_page(pfn1);
		end  = pfn_to_page(pfn2 - 1) + 1;

		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_limits(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_bank (i, mi) {
		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(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_bank(i, mi) {
		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 = -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 = -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 = 0;
		}
	}

	if (initrd == -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;
}

static void __init arm_bootmem_init(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;

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

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);
	pgdat = NODE_DATA(0);
	init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);

	for_each_bank(i, mi) {
		struct membank *bank = &mi->bank[i];
		if (!bank->highmem)
			free_bootmem(bank_phys_start(bank), bank_phys_size(bank));
	}

	/*
	 * Reserve the bootmem bitmap.
	 */
	reserve_bootmem(boot_pfn << PAGE_SHIFT,
			boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
}

static void __init bootmem_reserve_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
	int res;

	res = reserve_bootmem(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 arm_bootmem_free(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_limits(mi, &min, &max_low, &max_high);

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

	/*
	 * The memory size 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

	/*
	 * Calculate the size of the holes.
	 *  holes = node_size - sum(bank_sizes)
	 */
	memcpy(zhole_size, zone_size, sizeof(zhole_size));
	for_each_bank(i, mi) {
		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(0, zone_size, zhole_size);

	free_area_init_node(0, 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)
{
}
#else
static void arm_memory_present(struct meminfo *mi)
{
	int i;
	for_each_bank(i, mi) {
		struct membank *bank = &mi->bank[i];
		memory_present(0, bank_pfn_start(bank), bank_pfn_end(bank));
	}
}
#endif

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

	/*
	 * Locate the ramdisk image, if any.
	 */
	initrd = check_initrd(mi);

	max_low = max_high = 0;

	find_limits(mi, &min, &max_low, &max_high);

	arm_bootmem_init(mi, min, max_low);

	/*
	 * Reserve any special regions.
	 */
	reserve_special_regions();

	/*
	 * If the initrd is present, reserve its memory.
	 */
	if (initrd == 0)
		bootmem_reserve_initrd();

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

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

	/*
	 * Now free the memory - free_area_init_node needs
	 * the sparse mem_map arrays initialized by sparse_init()
	 * for memmap_init_zone(), otherwise all PFNs are invalid.
	 */
	arm_bootmem_free(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(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(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(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_bank(i, mi) {
		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(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 long reserved_pages, free_pages;
	int i;

	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;

	/* this will put all unused low memory onto the freelists */
	free_unused_memmap(&meminfo);

	totalram_pages += free_all_bootmem();

#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_bank (i, &meminfo) {
		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

	reserved_pages = free_pages = 0;

	for_each_bank(i, &meminfo) {
		struct membank *bank = &meminfo.bank[i];
		unsigned int pfn1, pfn2;
		struct page *page, *end;

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

		page = pfn_to_page(pfn1);
		end  = pfn_to_page(pfn2 - 1) + 1;

		do {
			if (PageReserved(page))
				reserved_pages++;
			else if (!page_count(page))
				free_pages++;
			page++;
		} while (page < end);
	}

	/*
	 * 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));

	printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
		nr_free_pages() << (PAGE_SHIFT-10),
		free_pages << (PAGE_SHIFT-10),
		reserved_pages << (PAGE_SHIFT-10),
		totalhigh_pages << (PAGE_SHIFT-10));

#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)

	printk(KERN_NOTICE "Virtual kernel memory layout:\n"
			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#ifdef CONFIG_MMU
			"    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#ifdef CONFIG_HIGHMEM
			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
			"      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
			"      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
			"      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",

			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
				(PAGE_SIZE)),
			MLK(FIXADDR_START, FIXADDR_TOP),
#ifdef CONFIG_MMU
			MLM(CONSISTENT_BASE, CONSISTENT_END),
#endif
			MLM(VMALLOC_START, VMALLOC_END),
			MLM(PAGE_OFFSET, (unsigned long)high_memory),
#ifdef CONFIG_HIGHMEM
			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
				(PAGE_SIZE)),
#endif
			MLM(MODULES_VADDR, MODULES_END),

			MLK_ROUNDUP(__init_begin, __init_end),
			MLK_ROUNDUP(_text, _etext),
			MLK_ROUNDUP(_data, _edata));

#undef MLK
#undef MLM
#undef MLK_ROUNDUP

	/*
	 * Check boundaries twice: Some fundamental inconsistencies can
	 * be detected at build time already.
	 */
#ifdef CONFIG_MMU
	BUILD_BUG_ON(VMALLOC_END			> CONSISTENT_BASE);
	BUG_ON(VMALLOC_END				> CONSISTENT_BASE);

	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
#endif

#ifdef CONFIG_HIGHMEM
	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
#endif

	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