2 * fixmap.h: compile-time virtual memory allocation
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
8 * Copyright (C) 1998 Ingo Molnar
11 #ifndef _ASM_FIXMAP_64_H
12 #define _ASM_FIXMAP_64_H
14 #include <linux/kernel.h>
15 #include <asm/apicdef.h>
17 #include <asm/vsyscall.h>
21 * Here we define all the compile-time 'special' virtual
22 * addresses. The point is to have a constant address at
23 * compile time, but to set the physical address only
24 * in the boot process.
26 * These 'compile-time allocated' memory buffers are
27 * fixed-size 4k pages (or larger if used with an increment
28 * higher than 1). Use set_fixmap(idx,phys) to associate
29 * physical memory with fixmap indices.
31 * TLB entries of such buffers will not be flushed across
35 enum fixed_addresses {
37 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
38 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
41 FIX_EARLYCON_MEM_BASE,
43 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
45 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
46 FIX_EFI_IO_MAP_LAST_PAGE,
47 FIX_EFI_IO_MAP_FIRST_PAGE = FIX_EFI_IO_MAP_LAST_PAGE
48 + MAX_EFI_IO_PAGES - 1,
49 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
52 __end_of_permanent_fixed_addresses,
54 * 256 temporary boot-time mappings, used by early_ioremap(),
55 * before ioremap() is functional.
57 * We round it up to the next 512 pages boundary so that we
58 * can have a single pgd entry and a single pte table:
60 #define NR_FIX_BTMAPS 64
61 #define FIX_BTMAPS_NESTING 4
62 FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 512 -
63 (__end_of_permanent_fixed_addresses & 511),
64 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
65 __end_of_fixed_addresses
68 #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
69 #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
70 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
72 /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
73 #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
74 #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)