path: root/arch/x86/mm/init_64.c

/*
 *  linux/arch/x86_64/mm/init.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
 *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
 */

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <linux/pci.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/memory_hotplug.h>
#include <linux/nmi.h>

#include <asm/processor.h>
#include <asm/bios_ebda.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/fixmap.h>
#include <asm/e820.h>
#include <asm/apic.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/proto.h>
#include <asm/smp.h>
#include <asm/sections.h>
#include <asm/kdebug.h>
#include <asm/numa.h>
#include <asm/cacheflush.h>

/*
 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
 * The direct mapping extends to max_pfn_mapped, so that we can directly access
 * apertures, ACPI and other tables without having to play with fixmaps.
 */
unsigned long max_low_pfn_mapped;
unsigned long max_pfn_mapped;

static unsigned long dma_reserve __initdata;

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

int direct_gbpages
#ifdef CONFIG_DIRECT_GBPAGES
				= 1
#endif
;

static int __init parse_direct_gbpages_off(char *arg)
{
	direct_gbpages = 0;
	return 0;
}
early_param("nogbpages", parse_direct_gbpages_off);

static int __init parse_direct_gbpages_on(char *arg)
{
	direct_gbpages = 1;
	return 0;
}
early_param("gbpages", parse_direct_gbpages_on);

/*
 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 * physical space so we can cache the place of the first one and move
 * around without checking the pgd every time.
 */

int after_bootmem;

pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
EXPORT_SYMBOL_GPL(__supported_pte_mask);

static int do_not_nx __cpuinitdata;

/*
 * noexec=on|off
 * Control non-executable mappings for 64-bit processes.
 *
 * on	Enable (default)
 * off	Disable
 */
static int __init nonx_setup(char *str)
{
	if (!str)
		return -EINVAL;
	if (!strncmp(str, "on", 2)) {
		__supported_pte_mask |= _PAGE_NX;
		do_not_nx = 0;
	} else if (!strncmp(str, "off", 3)) {
		do_not_nx = 1;
		__supported_pte_mask &= ~_PAGE_NX;
	}
	return 0;
}
early_param("noexec", nonx_setup);

void __cpuinit check_efer(void)
{
	unsigned long efer;

	rdmsrl(MSR_EFER, efer);
	if (!(efer & EFER_NX) || do_not_nx)
		__supported_pte_mask &= ~_PAGE_NX;
}

int force_personality32;

/*
 * noexec32=on|off
 * Control non executable heap for 32bit processes.
 * To control the stack too use noexec=off
 *
 * on	PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 * off	PROT_READ implies PROT_EXEC