arch/x86/include/asm/fixmap_64.h

/*
 * fixmap.h: compile-time virtual memory allocation
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1998 Ingo Molnar
 */

#ifndef _ASM_X86_FIXMAP_64_H
#define _ASM_X86_FIXMAP_64_H

#include <linux/kernel.h>
#include <asm/acpi.h>
#include <asm/apicdef.h>
#include <asm/page.h>
#include <asm/vsyscall.h>

/*
 * Here we define all the compile-time 'special' virtual
 * addresses. The point is to have a constant address at
 * compile time, but to set the physical address only
 * in the boot process.
 *
 * These 'compile-time allocated' memory buffers are
 * fixed-size 4k pages (or larger if used with an increment
 * higher than 1). Use set_fixmap(idx,phys) to associate
 * physical memory with fixmap indices.
 *
 * TLB entries of such buffers will not be flushed across
 * task switches.
 */

enum fixed_addresses {
	VSYSCALL_LAST_PAGE,
	VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
			    + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
	VSYSCALL_HPET,
	FIX_DBGP_BASE,
	FIX_EARLYCON_MEM_BASE,
	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
	FIX_IO_APIC_BASE_0,
	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
#ifdef CONFIG_PARAVIRT
	FIX_PARAVIRT_BOOTMAP,
#endif
	__end_of_permanent_fixed_addresses,
#ifdef CONFIG_ACPI
	FIX_ACPI_BEGIN,
	FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1,
#endif
#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
	FIX_OHCI1394_BASE,
#endif
	/*
	 * 256 temporary boot-time mappings, used by early_ioremap(),
	 * before ioremap() is functional.
	 *
	 * We round it up to the next 256 pages boundary so that we
	 * can have a single pgd entry and a single pte table:
	 */
#define NR_FIX_BTMAPS		64
#define FIX_BTMAPS_SLOTS	4
	FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 256 -
			(__end_of_permanent_fixed_addresses & 255),
	FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_SLOTS - 1,
	__end_of_fixed_addresses
};

#define FIXADDR_TOP	(VSYSCALL_END-PAGE_SIZE)
#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)

/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
#define FIXADDR_USER_START	((unsigned long)VSYSCALL32_VSYSCALL)
#define FIXADDR_USER_END	(FIXADDR_USER_START + PAGE_SIZE)

#endif /* _ASM_X86_FIXMAP_64_H */