fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-x86 / fixmap_64.h
blobcdfbe4a6ae6f1573f460e255d6309861f4aba6f3
1 /*
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
6 * for more details.
8 * Copyright (C) 1998 Ingo Molnar
9 */
11 #ifndef _ASM_FIXMAP_H
12 #define _ASM_FIXMAP_H
14 #include <linux/kernel.h>
15 #include <asm/apicdef.h>
16 #include <asm/page.h>
17 #include <asm/vsyscall.h>
20 * Here we define all the compile-time 'special' virtual
21 * addresses. The point is to have a constant address at
22 * compile time, but to set the physical address only
23 * in the boot process.
25 * These 'compile-time allocated' memory buffers are
26 * fixed-size 4k pages (or larger if used with an increment
27 * higher than 1). Use set_fixmap(idx,phys) to associate
28 * physical memory with fixmap indices.
30 * TLB entries of such buffers will not be flushed across
31 * task switches.
34 enum fixed_addresses {
35 VSYSCALL_LAST_PAGE,
36 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
37 VSYSCALL_HPET,
38 FIX_DBGP_BASE,
39 FIX_EARLYCON_MEM_BASE,
40 FIX_HPET_BASE,
41 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
42 FIX_IO_APIC_BASE_0,
43 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
44 __end_of_fixed_addresses
47 extern void __set_fixmap (enum fixed_addresses idx,
48 unsigned long phys, pgprot_t flags);
50 #define set_fixmap(idx, phys) \
51 __set_fixmap(idx, phys, PAGE_KERNEL)
53 * Some hardware wants to get fixmapped without caching.
55 #define set_fixmap_nocache(idx, phys) \
56 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
58 #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
59 #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
60 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
62 /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
63 #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
64 #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
66 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
68 extern void __this_fixmap_does_not_exist(void);
71 * 'index to address' translation. If anyone tries to use the idx
72 * directly without translation, we catch the bug with a NULL-deference
73 * kernel oops. Illegal ranges of incoming indices are caught too.
75 static __always_inline unsigned long fix_to_virt(const unsigned int idx)
78 * this branch gets completely eliminated after inlining,
79 * except when someone tries to use fixaddr indices in an
80 * illegal way. (such as mixing up address types or using
81 * out-of-range indices).
83 * If it doesn't get removed, the linker will complain
84 * loudly with a reasonably clear error message..
86 if (idx >= __end_of_fixed_addresses)
87 __this_fixmap_does_not_exist();
89 return __fix_to_virt(idx);
92 #endif