arch/i386/kernel/setup.c

/*
 *  linux/arch/i386/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *
 *  Memory region support
 *	David Parsons <orc@pell.chi.il.us>, July-August 1999
 *
 *  Added E820 sanitization routine (removes overlapping memory regions);
 *  Brian Moyle <bmoyle@mvista.com>, February 2001
 *
 * Moved CPU detection code to cpu/${cpu}.c
 *    Patrick Mochel <mochel@osdl.org>, March 2002
 *
 *  Provisions for empty E820 memory regions (reported by certain BIOSes).
 *  Alex Achenbach <xela@slit.de>, December 2002.
 *
 */

/*
 * This file handles the architecture-dependent parts of initialization
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/screen_info.h>
#include <linux/ioport.h>
#include <linux/acpi.h>
#include <linux/apm_bios.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/seq_file.h>
#include <linux/platform_device.h>
#include <linux/console.h>
#include <linux/mca.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/edd.h>
#include <linux/nodemask.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <linux/dmi.h>
#include <linux/pfn.h>

#include <video/edid.h>

#include <asm/apic.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/mmzone.h>
#include <asm/setup.h>
#include <asm/arch_hooks.h>
#include <asm/sections.h>
#include <asm/io_apic.h>
#include <asm/ist.h>
#include <asm/io.h>
#include <setup_arch.h>
#include <bios_ebda.h>

/* Forward Declaration. */
void __init find_max_pfn(void);

/* This value is set up by the early boot code to point to the value
   immediately after the boot time page tables.  It contains a *physical*
   address, and must not be in the .bss segment! */
unsigned long init_pg_tables_end __initdata = ~0UL;

int disable_pse __devinitdata = 0;

/*
 * Machine setup..
 */

#ifdef CONFIG_EFI
int efi_enabled = 0;
EXPORT_SYMBOL(efi_enabled);
#endif

/* cpu data as detected by the assembly code in head.S */
struct cpuinfo_x86 new_cpu_data __initdata = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
/* common cpu data for all cpus */
struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
EXPORT_SYMBOL(boot_cpu_data);

unsigned long mmu_cr4_features;

/* for MCA, but anyone else can use it if they want */
unsigned int machine_id;
#ifdef CONFIG_MCA
EXPORT_SYMBOL(machine_id);
#endif
unsigned int machine_submodel_id;
unsigned int BIOS_revision;
unsigned int mca_pentium_flag;

/* For PCI or other memory-mapped resources */
unsigned long pci_mem_start = 0x10000000;
#ifdef CONFIG_PCI
EXPORT_SYMBOL(pci_mem_start);
#endif

/* Boot loader ID as an integer, for the benefit of proc_dointvec */
int bootloader_type;

/* user-defined highmem size */
static unsigned int highmem_pages = -1;

/*
 * Setup options
 */
struct drive_info_struct { char dummy[32]; } drive_info;
#if defined(CONFIG_BLK_DEV_IDE) || defined(CONFIG_BLK_DEV_HD) || \
    defined(CONFIG_BLK_DEV_IDE_MODULE) || defined(CONFIG_BLK_DEV_HD_MODULE)
EXPORT_SYMBOL(drive_info);
#endif
struct screen_info screen_info;
EXPORT_SYMBOL(screen_info);
struct apm_info apm_info;
EXPORT_SYMBOL(apm_info);
struct sys_desc_table_struct {
	unsigned short length;
	unsigned char table[0];
};
struct edid_info edid_info;
EXPORT_SYMBOL_GPL(edid_info);
struct ist_info ist_info;
#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
EXPORT_SYMBOL(ist_info);
#endif
struct e820map e820;

extern void early_cpu_init(void);
extern int root_mountflags;

unsigned long saved_videomode;

#define RAMDISK_IMAGE_START_MASK  	0x07FF
#define RAMDISK_PROMPT_FLAG		0x8000
#define RAMDISK_LOAD_FLAG		0x4000	

static char command_line[COMMAND_LINE_SIZE];

unsigned char __initdata boot_params[PARAM_SIZE];

static struct resource data_resource = {
	.name	= "Kernel data",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
};

static struct resource code_resource = {
	.name	= "Kernel code",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
};

static struct resource system_rom_resource = {
	.name	= "System ROM",
	.start	= 0xf0000,
	.end	= 0xfffff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};

static struct resource extension_rom_resource = {
	.name	= "Extension ROM",
	.start	= 0xe0000,
	.end	= 0xeffff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};

static struct resource adapter_rom_resources[] = { {
	.name 	= "Adapter ROM",
	.start	= 0xc8000,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
	.name 	= "Adapter ROM",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
	.name 	= "Adapter ROM",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
	.name 	= "Adapter ROM",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
	.name 	= "Adapter ROM",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
	.name 	= "Adapter ROM",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
} };

#define ADAPTER_ROM_RESOURCES \
	(sizeof adapter_rom_resources / sizeof adapter_rom_resources[0])

static struct resource video_rom_resource = {
	.name 	= "Video ROM",
	.start	= 0xc0000,
	.end	= 0xc7fff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};

static struct resource video_ram_resource = {
	.name	= "Video RAM area",
	.start	= 0xa0000,
	.end	= 0xbffff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
};

static struct resource standard_io_resources[] = { {
	.name	= "dma1",
	.start	= 0x0000,
	.end	= 0x001f,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "pic1",
	.start	= 0x0020,
	.end	= 0x0021,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name   = "timer0",
	.start	= 0x0040,
	.end    = 0x0043,
	.flags  = IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name   = "timer1",
	.start  = 0x0050,
	.end    = 0x0053,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "keyboard",
	.start	= 0x0060,
	.end	= 0x006f,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "dma page reg",
	.start	= 0x0080,
	.end	= 0x008f,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "pic2",
	.start	= 0x00a0,
	.end	= 0x00a1,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "dma2",
	.start	= 0x00c0,
	.end	= 0x00df,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
}, {
	.name	= "fpu",
	.start	= 0x00f0,
	.end	= 0x00ff,
	.flags	= IORESOURCE_BUSY | IORESOURCE_IO
} };

#define STANDARD_IO_RESOURCES \
	(sizeof standard_io_resources / sizeof standard_io_resources[0])

#define romsignature(x) (*(unsigned short *)(x) == 0xaa55)

static int __init romchecksum(unsigned char *rom, unsigned long length)
{
	unsigned char *p, sum = 0;

	for (p = rom; p < rom + length; p++)
		sum += *p;
	return sum == 0;
}

static void __init probe_roms(void)
{
	unsigned long start, length, upper;
	unsigned char *rom;
	int	      i;

	/* video rom */
	upper = adapter_rom_resources[0].start;
	for (start = video_rom_resource.start; start < upper; start += 2048) {
		rom = isa_bus_to_virt(start);
		if (!romsignature(rom))
			continue;

		video_rom_resource.start = start;

		/* 0 < length <= 0x7f * 512, historically */
		length = rom[2] * 512;

		/* if checksum okay, trust length byte */
		if (length && romchecksum(rom, length))
			video_rom_resource.end = start + length - 1;

		request_resource(&iomem_resource, &video_rom_resource);
		break;
	}

	start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
	if (start < upper)
		start = upper;

	/* system rom */
	request_resource(&iomem_resource, &system_rom_resource);
	upper = system_rom_resource.start;

	/* check for extension rom (ignore length byte!) */
	rom = isa_bus_to_virt(extension_rom_resource.start);
	if (romsignature(rom)) {
		length = extension_rom_resource.end - extension_rom_resource.start + 1;
		if (romchecksum(rom, length)) {
			request_resource(&iomem_resource, &extension_rom_resource);
			upper = extension_rom_resource.start;
		}
	}

	/* check for adapter roms on 2k boundaries */
	for (i = 0; i < ADAPTER_ROM_RESOURCES && start < upper; start += 2048) {
		rom = isa_bus_to_virt(start);
		if (!romsignature(rom))
			continue;

		/* 0 < length <= 0x7f * 512, historically */
		length = rom[2] * 512;

		/* but accept any length that fits if checksum okay */
		if (!length || start + length > upper || !romchecksum(rom, length))
			continue;

		adapter_rom_resources[i].start = start;
		adapter_rom_resources[i].end = start + length - 1;
		request_resource(&iomem_resource, &adapter_rom_resources[i]);

		start = adapter_rom_resources[i++].end & ~2047UL;
	}
}

static void __init limit_regions(unsigned long long size)
{
	unsigned long long current_addr = 0;
	int i;

	if (efi_enabled) {
		efi_memory_desc_t *md;
		void *p;

		for (p = memmap.map, i = 0; p < memmap.map_end;
			p += memmap.desc_size, i++) {
			md = p;
			current_addr = md->phys_addr + (md->num_pages << 12);
			if (md->type == EFI_CONVENTIONAL_MEMORY) {
				if (current_addr >= size) {
					md->num_pages -=
						(((current_addr-size) + PAGE_SIZE-1) >> PAGE_SHIFT);
					memmap.nr_map = i + 1;
					return;
				}
			}
		}
	}
	for (i = 0; i < e820.nr_map; i++) {
		current_addr = e820.map[i].addr + e820.map[i].size;
		if (current_addr < size)
			continue;

		if (e820.map[i].type != E820_RAM)
			continue;

		if (e820.map[i].addr >= size) {
			/*
			 * This region starts past the end of the
			 * requested size, skip it completely.
			 */
			e820.nr_map = i;
		} else {
			e820.nr_map = i + 1;
			e820.map[i].size -= current_addr - size;
		}
		return;
	}
}

void __init add_memory_region(unsigned long long start,
			      unsigned long long size, int type)
{
	int x;

	if (!efi_enabled) {
       		x = e820.nr_map;

		if (x == E820MAX) {
		    printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
		    return;
		}

		e820.map[x].addr = start;
		e820.map[x].size = size;
		e820.map[x].type = type;
		e820.nr_map++;
	}
} /* add_memory_region */

#define E820_DEBUG	1

static void __init print_memory_map(char *who)
{
	int i;

	for (i = 0; i < e820.nr_map; i++) {
		printk(" %s: %016Lx - %016Lx ", who,
			e820.map[i].addr,
			e820.map[i].addr + e820.map[i].size);
		switch (e820.map[i].type) {
		case E820_RAM:	printk("(usable)\n");
				break;
		case E820_RESERVED:
				printk("(reserved)\n");
				break;
		case E820_ACPI:
				printk("(ACPI data)\n");
				break;
		case E820_NVS:
				printk("(ACPI NVS)\n");
				break;
		default:	printk("type %lu\n", e820.map[i].type);
				break;
		}
	}
}

/*
 * Sanitize the BIOS e820 map.
 *
 * Some e820 responses include overlapping entries.  The following 
 * replaces the original e820 map with a new one, removing overlaps.
 *
 */
struct change_member {
	struct e820entry *pbios; /* pointer to original bios entry */
	unsigned long long addr; /* address for this change point */
};
static struct change_member change_point_list[2*E820MAX] __initdata;
static struct change_member *change_point[2*E820MAX] __initdata;
static struct e820entry *overlap_list[E820MAX] __initdata;
static struct e820entry new_bios[E820MAX] __initdata;

int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
{
	struct change_member *change_tmp;
	unsigned long current_type, last_type;
	unsigned long long last_addr;
	int chgidx, still_changing;
	int overlap_entries;
	int new_bios_entry;
	int old_nr, new_nr, chg_nr;
	int i;

	/*
		Visually we're performing the following (1,2,3,4 = memory types)...

		Sample memory map (w/overlaps):
		   ____22__________________
		   ______________________4_
		   ____1111________________
		   _44_____________________
		   11111111________________
		   ____________________33__
		   ___________44___________
		   __________33333_________
		   ______________22________
		   ___________________2222_
		   _________111111111______
		   _____________________11_
		   _________________4______

		Sanitized equivalent (no overlap):
		   1_______________________
		   _44_____________________
		   ___1____________________
		   ____22__________________
		   ______11________________
		   _________1______________
		   __________3_____________
		   ___________44___________
		   _____________33_________
		   _______________2________
		   ________________1_______
		   _________________4______
		   ___________________2____
		   ____________________33__
		   ______________________4_
	*/

	/* if there's only one memory region, don't bother */
	if (*pnr_map < 2)
		return -1;

	old_nr = *pnr_map;

	/* bail out if we find any unreasonable addresses in bios map */
	for (i=0; i<old_nr; i++)
		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
			return -1;

	/* create pointers for initial change-point information (for sorting) */
	for (i=0; i < 2*old_nr; i++)
		change_point[i] = &change_point_list[i];

	/* record all known change-points (starting and ending addresses),
	   omitting those that are for empty memory regions */
	chgidx = 0;
	for (i=0; i < old_nr; i++)	{
		if (biosmap[i].size != 0) {
			change_point[chgidx]->addr = biosmap[i].addr;
			change_point[chgidx++]->pbios = &biosmap[i];
			change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
			change_point[chgidx++]->pbios = &biosmap[i];
		}
	}
	chg_nr = chgidx;    	/* true number of change-points */

	/* sort change-point list by memory addresses (low -> high) */
	still_changing = 1;
	while (still_changing)	{
		still_changing = 0;
		for (i=1; i < chg_nr; i++)  {
			/* if <current_addr> > <last_addr>, swap */
			/* or, if current=<start_addr> & last=<end_addr>, swap */
			if ((change_point[i]->addr < change_point[i-1]->addr) ||
				((change_point[i]->addr == change_point[i-1]->addr) &&
				 (change_point[i]->addr == change_point[i]->pbios->addr) &&
				 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
			   )
			{
				change_tmp = change_point[i];
				change_point[i] = change_point[i-1];
				change_point[i-1] = change_tmp;
				still_changing=1;
			}
		}
	}

	/* create a new bios memory map, removing overlaps */
	overlap_entries=0;	 /* number of entries in the overlap table */
	new_bios_entry=0;	 /* index for creating new bios map entries */
	last_type = 0;		 /* start with undefined memory type */
	last_addr = 0;		 /* start with 0 as last starting address */
	/* loop through change-points, determining affect on the new bios map */
	for (chgidx=0; chgidx < chg_nr; chgidx++)
	{
		/* keep track of all overlapping bios entries */
		if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
		{
			/* add map entry to overlap list (> 1 entry implies an overlap) */
			overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
		}
		else
		{
			/* remove entry from list (order independent, so swap with last) */
			for (i=0; i<overlap_entries; i++)
			{
				if (overlap_list[i] == change_point[chgidx]->pbios)
					overlap_list[i] = overlap_list[overlap_entries-1];
			}
			overlap_entries--;
		}
		/* if there are overlapping entries, decide which "type" to use */
		/* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
		current_type = 0;
		for (i=0; i<overlap_entries; i++)
			if (overlap_list[i]->type > current_type)
				current_type = overlap_list[i]->type;
		/* continue building up new bios map based on this information */
		if (current_type != last_type)	{
			if (last_type != 0)	 {
				new_bios[new_bios_entry].size =
					change_point[chgidx]->addr - last_addr;
				/* move forward only if the new size was non-zero */
				if (new_bios[new_bios_entry].size != 0)
					if (++new_bios_entry >= E820MAX)
						break; 	/* no more space left for new bios entries */
			}
			if (current_type != 0)	{
				new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
				new_bios[new_bios_entry].type = current_type;
				last_addr=change_point[chgidx]->addr;
			}
			last_type = current_type;
		}
	}
	new_nr = new_bios_entry;   /* retain count for new bios entries */

	/* copy new bios mapping into original location */
	memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
	*pnr_map = new_nr;

	return 0;
}

/*
 * Copy the BIOS e820 map into a safe place.
 *
 * Sanity-check it while we're at it..
 *
 * If we're lucky and live on a modern system, the setup code
 * will have given us a memory map that we can use to properly
 * set up memory.  If we aren't, we'll fake a memory map.
 *
 * We check to see that the memory map contains at least 2 elements
 * before we'll use it, because the detection code in setup.S may
 * not be perfect and most every PC known to man has two memory
 * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
 * thinkpad 560x, for example, does not cooperate with the memory
 * detection code.)
 */
int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
{
	/* Only one memory region (or negative)? Ignore it */
	if (nr_map < 2)
		return -1;

	do {
		unsigned long long start = biosmap->addr;
		unsigned long long size = biosmap->size;
		unsigned long long end = start + size;
		unsigned long type = biosmap->type;

		/* Overflow in 64 bits? Ignore the memory map. */
		if (start > end)
			return -1;

		/*
		 * Some BIOSes claim RAM in the 640k - 1M region.
		 * Not right. Fix it up.
		 */
		if (type == E820_RAM) {
			if (start < 0x100000ULL && end > 0xA0000ULL) {
				if (start < 0xA0000ULL)
					add_memory_region(start, 0xA0000ULL-start, type);
				if (end <= 0x100000ULL)
					continue;
				start = 0x100000ULL;
				size = end - start;
			}
		}
		add_memory_region(start, size, type);
	} while (biosmap++,--nr_map);
	return 0;
}

#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
struct edd edd;
#ifdef CONFIG_EDD_MODULE
EXPORT_SYMBOL(edd);
#endif
/**
 * copy_edd() - Copy the BIOS EDD information
 *              from boot_params into a safe place.
 *
 */
static inline void copy_edd(void)
{
     memcpy(edd.mbr_signature, EDD_MBR_SIGNATURE, sizeof(edd.mbr_signature));
     memcpy(edd.edd_info, EDD_BUF, sizeof(edd.edd_info));
     edd.mbr_signature_nr = EDD_MBR_SIG_NR;
     edd.edd_info_nr = EDD_NR;
}
#else
static inline void copy_edd(void)
{
}
#endif

static int __initdata user_defined_memmap = 0;

/*
 * "mem=nopentium" disables the 4MB page tables.
 * "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
 * to <mem>, overriding the bios size.
 * "memmap=XXX[KkmM]@XXX[KkmM]" defines a memory region from
 * <start> to <start>+<mem>, overriding the bios size.
 *
 * HPA tells me bootloaders need to parse mem=, so no new
 * option should be mem=  [also see Documentation/i386/boot.txt]
 */
static int __init parse_mem(char *arg)
{
	if (!arg)
		return -EINVAL;

	if (strcmp(arg, "nopentium") == 0) {
		clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
		disable_pse = 1;
	} else {
		/* If the user specifies memory size, we
		 * limit the BIOS-provided memory map to
		 * that size. exactmap can be used to specify
		 * the exact map. mem=number can be used to
		 * trim the existing memory map.
		 */
		unsigned long long mem_size;
 
		mem_size = memparse(arg, &arg);
		limit_regions(mem_size);
		user_defined_memmap = 1;
	}
	return 0;
}
early_param("mem", parse_mem);

static int __init parse_memmap(char *arg)
{
	if (!arg)
		return -EINVAL;

	if (strcmp(arg, "exactmap") == 0) {
#ifdef CONFIG_CRASH_DUMP
		/* If we are doing a crash dump, we
		 * still need to know the real mem
		 * size before original memory map is
		 * reset.
		 */
		find_max_pfn();
		saved_max_pfn = max_pfn;
#endif
		e820.nr_map = 0;
		user_defined_memmap = 1;
	} else {
		/* If the user specifies memory size, we
		 * limit the BIOS-provided memory map to
		 * that size. exactmap can be used to specify
		 * the exact map. mem=number can be used to
		 * trim the existing memory map.
		 */
		unsigned long long start_at, mem_size;

		mem_size = memparse(arg, &arg);
		if (*arg == '@') {
			start_at = memparse(arg+1, &arg);
			add_memory_region(start_at, mem_size, E820_RAM);
		} else if (*arg == '#') {
			start_at = memparse(arg+1, &arg);
			add_memory_region(start_at, mem_size, E820_ACPI);
		} else if (*arg == '$') {
			start_at = memparse(arg+1, &arg);
			add_memory_region(start_at, mem_size, E820_RESERVED);
		} else {
			limit_regions(mem_size);
			user_defined_memmap = 1;
		}
	}
	return 0;
}
early_param("memmap", parse_memmap);

#ifdef CONFIG_PROC_VMCORE
/* elfcorehdr= specifies the location of elf core header
 * stored by the crashed kernel.
 */
static int __init parse_elfcorehdr(char *arg)
{
	if (!arg)
		return -EINVAL;

	elfcorehdr_addr = memparse(arg, &arg);
	return 0;
}
early_param("elfcorehdr", parse_elfcorehdr);
#endif /* CONFIG_PROC_VMCORE */

/*
 * highmem=size forces highmem to be exactly 'size' bytes.
 * This works even on boxes that have no highmem otherwise.
 * This also works to reduce highmem size on bigger boxes.
 */
static int __init parse_highmem(char *arg)
{
	if (!arg)
		return -EINVAL;

	highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
	return 0;
}
early_param("highmem", parse_highmem);

/*
 * vmalloc=size forces the vmalloc area to be exactly 'size'
 * bytes. This can be used to increase (or decrease) the
 * vmalloc area - the default is 128m.
 */
static int __init parse_vmalloc(char *arg)
{
	if (!arg)
		return -EINVAL;

	__VMALLOC_RESERVE = memparse(arg, &arg);
	return 0;
}
early_param("vmalloc", parse_vmalloc);

/*
 * reservetop=size reserves a hole at the top of the kernel address space which
 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
 * so relocating the fixmap can be done before paging initialization.
 */
static int __init parse_reservetop(char *arg)
{
	unsigned long address;

	if (!arg)
		return -EINVAL;

	address = memparse(arg, &arg);
	reserve_top_address(address);
	return 0;
}
early_param("reservetop", parse_reservetop);

/*
 * Callback for efi_memory_walk.
 */
static int __init
efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
{
	unsigned long *max_pfn = arg, pfn;

	if (start < end) {
		pfn = PFN_UP(end -1);
		if (pfn > *max_pfn)
			*max_pfn = pfn;
	}
	return 0;
}

static int __init
efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
{
	memory_present(0, start, end);
	return 0;
}

 /*
  * This function checks if the entire range <start,end> is mapped with type.
  *
  * Note: this function only works correct if the e820 table is sorted and
  * not-overlapping, which is the case
  */
int __init
e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
{
	u64 start = s;
	u64 end = e;
	int i;
	for (i = 0; i < e820.nr_map; i++) {
		struct e820entry *ei = &e820.map[i];
		if (type && ei->type != type)
			continue;
		/* is the region (part) in overlap with the current region ?*/
		if (ei->addr >= end || ei->addr + ei->size <= start)
			continue;
		/* if the region is at the beginning of <start,end> we move
		 * start to the end of the region since it's ok until there
		 */
		if (ei->addr <= start)
			start = ei->addr + ei->size;
		/* if start is now at or beyond end, we're done, full
		 * coverage */
		if (start >= end)
			return 1; /* we're done */
	}
	return 0;
}

/*
 * Find the highest page frame number we have available
 */
void __init find_max_pfn(void)
{
	int i;

	max_pfn = 0;
	if (efi_enabled) {
		efi_memmap_walk(efi_find_max_pfn, &max_pfn);
		efi_memmap_walk(efi_memory_present_wrapper, NULL);
		return;
	}

	for (i = 0; i < e820.nr_map; i++) {
		unsigned long start, end;
		/* RAM? */
		if (e820.map[i].type != E820_RAM)
			continue;
		start = PFN_UP(e820.map[i].addr);
		end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
		if (start >= end)
			continue;
		if (end > max_pfn)
			max_pfn = end;
		memory_present(0, start, end);
	}
}

/*
 * Determine low and high memory ranges:
 */
unsigned long __init find_max_low_pfn(void)
{
	unsigned long max_low_pfn;

	max_low_pfn = max_pfn;
	if (max_low_pfn > MAXMEM_PFN) {
		if (highmem_pages == -1)
			highmem_pages = max_pfn - MAXMEM_PFN;
		if (highmem_pages + MAXMEM_PFN < max_pfn)
			max_pfn = MAXMEM_PFN + highmem_pages;
		if (highmem_pages + MAXMEM_PFN > max_pfn) {
			printk("only %luMB highmem pages available, ignoring highmem size of %uMB.\n", pages_to_mb(max_pfn - MAXMEM_PFN), pages_to_mb(highmem_pages));
			highmem_pages = 0;
		}
		max_low_pfn = MAXMEM_PFN;
#ifndef CONFIG_HIGHMEM
		/* Maximum memory usable is what is directly addressable */
		printk(KERN_WARNING "Warning only %ldMB will be used.\n",
					MAXMEM>>20);
		if (max_pfn > MAX_NONPAE_PFN)
			printk(KERN_WARNING "Use a PAE enabled kernel.\n");
		else
			printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
		max_pfn = MAXMEM_PFN;
#else /* !CONFIG_HIGHMEM */
#ifndef CONFIG_X86_PAE
		if (max_pfn > MAX_NONPAE_PFN) {
			max_pfn = MAX_NONPAE_PFN;
			printk(KERN_WARNING "Warning only 4GB will be used.\n");
			printk(KERN_WARNING "Use a PAE enabled kernel.\n");
		}
#endif /* !CONFIG_X86_PAE */
#endif /* !CONFIG_HIGHMEM */
	} else {
		if (highmem_pages == -1)
			highmem_pages = 0;
#ifdef CONFIG_HIGHMEM
		if (highmem_pages >= max_pfn) {
			printk(KERN_ERR "highmem size specified (%uMB) is bigger than pages available (%luMB)!.\n", pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
			highmem_pages = 0;
		}
		if (highmem_pages) {
			if (max_low_pfn-highmem_pages < 64*1024*1024/PAGE_SIZE){
				printk(KERN_ERR "highmem size %uMB results in smaller than 64MB lowmem, ignoring it.\n", pages_to_mb(highmem_pages));
				highmem_pages = 0;
			}
			max_low_pfn -= highmem_pages;
		}
#else
		if (highmem_pages)
			printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
#endif
	}
	return max_low_pfn;
}

/*
 * Free all available memory for boot time allocation.  Used
 * as a callback function by efi_memory_walk()
 */

static int __init
free_available_memory(unsigned long start, unsigned long end, void *arg)
{
	/* check max_low_pfn */
	if (start >= (max_low_pfn << PAGE_SHIFT))
		return 0;
	if (end >= (max_low_pfn << PAGE_SHIFT))
		end = max_low_pfn << PAGE_SHIFT;
	if (start < end)
		free_bootmem(start, end - start);

	return 0;
}
/*
 * Register fully available low RAM pages with the bootmem allocator.
 */
static void __init register_bootmem_low_pages(unsigned long max_low_pfn)
{
	int i;

	if (efi_enabled) {
		efi_memmap_walk(free_available_memory, NULL);
		return;
	}
	for (i = 0; i < e820.nr_map; i++) {
		unsigned long curr_pfn, last_pfn, size;
		/*
		 * Reserve usable low memory
		 */
		if (e820.map[i].type != E820_RAM)
			continue;
		/*
		 * We are rounding up the start address of usable memory:
		 */
		curr_pfn = PFN_UP(e820.map[i].addr);
		if (curr_pfn >= max_low_pfn)
			continue;
		/*
		 * ... and at the end of the usable range downwards:
		 */
		last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);

		if (last_pfn > max_low_pfn)
			last_pfn = max_low_pfn;

		/*
		 * .. finally, did all the rounding and playing
		 * around just make the area go away?
		 */
		if (last_pfn <= curr_pfn)
			continue;

		size = last_pfn - curr_pfn;
		free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
	}
}

/*
 * workaround for Dell systems that neglect to reserve EBDA
 */
static void __init reserve_ebda_region(void)
{
	unsigned int addr;
	addr = get_bios_ebda();
	if (addr)
		reserve_bootmem(addr, PAGE_SIZE);	
}

#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init setup_bootmem_allocator(void);
static unsigned long __init setup_memory(void)
{
	/*
	 * partially used pages are not usable - thus
	 * we are rounding upwards:
	 */
	min_low_pfn = PFN_UP(init_pg_tables_end);

	find_max_pfn();

	max_low_pfn = find_max_low_pfn();

#ifdef CONFIG_HIGHMEM
	highstart_pfn = highend_pfn = max_pfn;
	if (max_pfn > max_low_pfn) {
		highstart_pfn = max_low_pfn;
	}
	printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
		pages_to_mb(highend_pfn - highstart_pfn));
	num_physpages = highend_pfn;
	high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
#else
	num_physpages = max_low_pfn;
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
#endif
#ifdef CONFIG_FLATMEM
	max_mapnr = num_physpages;
#endif
	printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
			pages_to_mb(max_low_pfn));

	setup_bootmem_allocator();

	return max_low_pfn;
}

void __init zone_sizes_init(void)
{
#ifdef CONFIG_HIGHMEM
	unsigned long max_zone_pfns[MAX_NR_ZONES] = {
			virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT,
			max_low_pfn,
			highend_pfn};
	add_active_range(0, 0, highend_pfn);
#else
	unsigned long max_zone_pfns[MAX_NR_ZONES] = {
			virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT,
			max_low_pfn};
	add_active_range(0, 0, max_low_pfn);
#endif

	free_area_init_nodes(max_zone_pfns);
}
#else
extern unsigned long __init setup_memory(void);
extern void zone_sizes_init(void);
#endif /* !CONFIG_NEED_MULTIPLE_NODES */

void __init setup_bootmem_allocator(void)
{
	unsigned long bootmap_size;
	/*
	 * Initialize the boot-time allocator (with low memory only):
	 */
	bootmap_size = init_bootmem(min_low_pfn, max_low_pfn);

	register_bootmem_low_pages(max_low_pfn);

	/*
	 * Reserve the bootmem bitmap itself as well. We do this in two
	 * steps (first step was init_bootmem()) because this catches
	 * the (very unlikely) case of us accidentally initializing the
	 * bootmem allocator with an invalid RAM area.
	 */
	reserve_bootmem(__PHYSICAL_START, (PFN_PHYS(min_low_pfn) +
			 bootmap_size + PAGE_SIZE-1) - (__PHYSICAL_START));

	/*
	 * reserve physical page 0 - it's a special BIOS page on many boxes,
	 * enabling clean reboots, SMP operation, laptop functions.
	 */
	reserve_bootmem(0, PAGE_SIZE);

	/* reserve EBDA region, it's a 4K region */
	reserve_ebda_region();

    /* could be an AMD 768MPX chipset. Reserve a page  before VGA to prevent
       PCI prefetch into it (errata #56). Usually the page is reserved anyways,
       unless you have no PS/2 mouse plugged in. */
	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
	    boot_cpu_data.x86 == 6)
	     reserve_bootmem(0xa0000 - 4096, 4096);

#ifdef CONFIG_SMP
	/*
	 * But first pinch a few for the stack/trampoline stuff
	 * FIXME: Don't need the extra page at 4K, but need to fix
	 * trampoline before removing it. (see the GDT stuff)
	 */
	reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
#endif
#ifdef CONFIG_ACPI_SLEEP
	/*
	 * Reserve low memory region for sleep support.
	 */
	acpi_reserve_bootmem();
#endif
#ifdef CONFIG_X86_FIND_SMP_CONFIG
	/*
	 * Find and reserve possible boot-time SMP configuration:
	 */
	find_smp_config();
#endif
	numa_kva_reserve();
#ifdef CONFIG_BLK_DEV_INITRD
	if (LOADER_TYPE && INITRD_START) {
		if (INITRD_START + INITRD_SIZE <= (max_low_pfn << PAGE_SHIFT)) {
			reserve_bootmem(INITRD_START, INITRD_SIZE);
			initrd_start =
				INITRD_START ? INITRD_START + PAGE_OFFSET : 0;
			initrd_end = initrd_start+INITRD_SIZE;
		}
		else {
			printk(KERN_ERR "initrd extends beyond end of memory "
			    "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
			    INITRD_START + INITRD_SIZE,
			    max_low_pfn << PAGE_SHIFT);
			initrd_start = 0;
		}
	}
#endif
#ifdef CONFIG_KEXEC
	if (crashk_res.start != crashk_res.end)
		reserve_bootmem(crashk_res.start,
			crashk_res.end - crashk_res.start + 1);
#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.
 */
static void __init
legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
{
	int i;

	probe_roms();
	for (i = 0; i < e820.nr_map; i++) {
		struct resource *res;
#ifndef CONFIG_RESOURCES_64BIT
		if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
			continue;
#endif
		res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
		switch (e820.map[i].type) {
		case E820_RAM:	res->name = "System RAM"; break;
		case E820_ACPI:	res->name = "ACPI Tables"; break;
		case E820_NVS:	res->name = "ACPI Non-volatile Storage"; break;
		default:	res->name = "reserved";
		}
		res->start = e820.map[i].addr;
		res->end = res->start + e820.map[i].size - 1;
		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
		if (request_resource(&iomem_resource, res)) {
			kfree(res);
			continue;
		}
		if (e820.map[i].type == E820_RAM) {
			/*
			 *  We don't know which RAM region contains kernel data,
			 *  so we try it repeatedly and let the resource manager
			 *  test it.
			 */
			request_resource(res, code_resource);
			request_resource(res, data_resource);
#ifdef CONFIG_KEXEC
			request_resource(res, &crashk_res);
#endif
		}
	}
}

/*
 * Request address space for all standard resources
 *
 * This is called just before pcibios_init(), which is also a
 * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
 */
static int __init request_standard_resources(void)
{
	int i;

	printk("Setting up standard PCI resources\n");
	if (efi_enabled)
		efi_initialize_iomem_resources(&code_resource, &data_resource);
	else
		legacy_init_iomem_resources(&code_resource, &data_resource);

	/* EFI systems may still have VGA */
	request_resource(&iomem_resource, &video_ram_resource);

	/* request I/O space for devices used on all i[345]86 PCs */
	for (i = 0; i < STANDARD_IO_RESOURCES; i++)
		request_resource(&ioport_resource, &standard_io_resources[i]);
	return 0;
}

subsys_initcall(request_standard_resources);

static void __init register_memory(void)
{
	unsigned long gapstart, gapsize, round;
	unsigned long long last;
	int i;

	/*
	 * Search for the bigest gap in the low 32 bits of the e820
	 * memory space.
	 */
	last = 0x100000000ull;
	gapstart = 0x10000000;
	gapsize = 0x400000;
	i = e820.nr_map;
	while (--i >= 0) {
		unsigned long long start = e820.map[i].addr;
		unsigned long long end = start + e820.map[i].size;

		/*
		 * Since "last" is at most 4GB, we know we'll
		 * fit in 32 bits if this condition is true
		 */
		if (last > end) {
			unsigned long gap = last - end;

			if (gap > gapsize) {
				gapsize = gap;
				gapstart = end;
			}
		}
		if (start < last)
			last = start;
	}

	/*
	 * See how much we want to round up: start off with
	 * rounding to the next 1MB area.
	 */
	round = 0x100000;
	while ((gapsize >> 4) > round)
		round += round;
	/* Fun with two's complement */
	pci_mem_start = (gapstart + round) & -round;

	printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
		pci_mem_start, gapstart, gapsize);
}

#ifdef CONFIG_MCA
static void set_mca_bus(int x)
{
	MCA_bus = x;
}
#else
static void set_mca_bus(int x) { }
#endif

/*
 * Determine if we were loaded by an EFI loader.  If so, then we have also been
 * passed the efi memmap, systab, etc., so we should use these data structures
 * for initialization.  Note, the efi init code path is determined by the
 * global efi_enabled. This allows the same kernel image to be used on existing
 * systems (with a traditional BIOS) as well as on EFI systems.
 */
void __init setup_arch(char **cmdline_p)
{
	unsigned long max_low_pfn;

	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
	pre_setup_arch_hook();
	early_cpu_init();

	/*
	 * FIXME: This isn't an official loader_type right
	 * now but does currently work with elilo.
	 * If we were configured as an EFI kernel, check to make
	 * sure that we were loaded correctly from elilo and that
	 * the system table is valid.  If not, then initialize normally.
	 */
#ifdef CONFIG_EFI
	if ((LOADER_TYPE == 0x50) && EFI_SYSTAB)
		efi_enabled = 1;
#endif

 	ROOT_DEV = old_decode_dev(ORIG_ROOT_DEV);
 	drive_info = DRIVE_INFO;
 	screen_info = SCREEN_INFO;
	edid_info = EDID_INFO;
	apm_info.bios = APM_BIOS_INFO;
	ist_info = IST_INFO;
	saved_videomode = VIDEO_MODE;
	if( SYS_DESC_TABLE.length != 0 ) {
		set_mca_bus(SYS_DESC_TABLE.table[3] & 0x2);
		machine_id = SYS_DESC_TABLE.table[0];
		machine_submodel_id = SYS_DESC_TABLE.table[1];
		BIOS_revision = SYS_DESC_TABLE.table[2];
	}
	bootloader_type = LOADER_TYPE;

#ifdef CONFIG_BLK_DEV_RAM
	rd_image_start = RAMDISK_FLAGS & RAMDISK_IMAGE_START_MASK;
	rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
	rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
#endif
	ARCH_SETUP
	if (efi_enabled)
		efi_init();
	else {
		printk(KERN_INFO "BIOS-provided physical RAM map:\n");
		print_memory_map(machine_specific_memory_setup());
	}

	copy_edd();

	if (!MOUNT_ROOT_RDONLY)
		root_mountflags &= ~MS_RDONLY;
	init_mm.start_code = (unsigned long) _text;
	init_mm.end_code = (unsigned long) _etext;
	init_mm.end_data = (unsigned long) _edata;
	init_mm.brk = init_pg_tables_end + PAGE_OFFSET;

	code_resource.start = virt_to_phys(_text);
	code_resource.end = virt_to_phys(_etext)-1;
	data_resource.start = virt_to_phys(_etext);
	data_resource.end = virt_to_phys(_edata)-1;

	parse_early_param();

	if (user_defined_memmap) {
		printk(KERN_INFO "user-defined physical RAM map:\n");
		print_memory_map("user");
	}

	strlcpy(command_line, saved_command_line, COMMAND_LINE_SIZE);
	*cmdline_p = command_line;

	max_low_pfn = setup_memory();

	/*
	 * NOTE: before this point _nobody_ is allowed to allocate
	 * any memory using the bootmem allocator.  Although the
	 * alloctor is now initialised only the first 8Mb of the kernel
	 * virtual address space has been mapped.  All allocations before
	 * paging_init() has completed must use the alloc_bootmem_low_pages()
	 * variant (which allocates DMA'able memory) and care must be taken
	 * not to exceed the 8Mb limit.
	 */

#ifdef CONFIG_SMP
	smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
#endif
	paging_init();
	remapped_pgdat_init();
	sparse_init();
	zone_sizes_init();

	/*
	 * NOTE: at this point the bootmem allocator is fully available.
	 */

	dmi_scan_machine();

#ifdef CONFIG_X86_GENERICARCH
	generic_apic_probe();
#endif	
	if (efi_enabled)
		efi_map_memmap();

#ifdef CONFIG_ACPI
	/*
	 * Parse the ACPI tables for possible boot-time SMP configuration.
	 */
	acpi_boot_table_init();
#endif

#ifdef CONFIG_PCI
#ifdef CONFIG_X86_IO_APIC
	check_acpi_pci();	/* Checks more than just ACPI actually */
#endif
#endif

#ifdef CONFIG_ACPI
	acpi_boot_init();

#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
	if (def_to_bigsmp)
		printk(KERN_WARNING "More than 8 CPUs detected and "
			"CONFIG_X86_PC cannot handle it.\nUse "
			"CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
#endif
#endif
#ifdef CONFIG_X86_LOCAL_APIC
	if (smp_found_config)
		get_smp_config();
#endif

	register_memory();

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
	if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
		conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
	conswitchp = &dummy_con;
#endif
#endif
	tsc_init();
}

static __init int add_pcspkr(void)
{
	struct platform_device *pd;
	int ret;

	pd = platform_device_alloc("pcspkr", -1);
	if (!pd)
		return -ENOMEM;

	ret = platform_device_add(pd);
	if (ret)
		platform_device_put(pd);

	return ret;
}
device_initcall(add_pcspkr);

/*
 * Local Variables:
 * mode:c
 * c-file-style:"k&r"
 * c-basic-offset:8
 * End:
 */