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1/*
2 * fixmap.h: compile-time virtual memory allocation
3 *
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.
7 *
8 * Copyright (C) 1998 Ingo Molnar
9 *
10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
11 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
12 */
13
14#ifndef _ASM_X86_FIXMAP_H
15#define _ASM_X86_FIXMAP_H
16
17#ifndef __ASSEMBLY__
18#include <linux/kernel.h>
19#include <asm/acpi.h>
20#include <asm/apicdef.h>
21#include <asm/page.h>
22#ifdef CONFIG_X86_32
23#include <linux/threads.h>
24#include <asm/kmap_types.h>
25#else
26#include <asm/vsyscall.h>
27#endif
28
29/*
30 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
31 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
32 * Because of this, FIXADDR_TOP x86 integration was left as later work.
33 */
34#ifdef CONFIG_X86_32
35/* used by vmalloc.c, vsyscall.lds.S.
36 *
37 * Leave one empty page between vmalloc'ed areas and
38 * the start of the fixmap.
39 */
40extern unsigned long __FIXADDR_TOP;
41#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
42
43#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO)
44#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1)
45#else
46#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
47
48/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
49#define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
50#define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
51#endif
52
53
54/*
55 * Here we define all the compile-time 'special' virtual
56 * addresses. The point is to have a constant address at
57 * compile time, but to set the physical address only
58 * in the boot process.
59 * for x86_32: We allocate these special addresses
60 * from the end of virtual memory (0xfffff000) backwards.
61 * Also this lets us do fail-safe vmalloc(), we
62 * can guarantee that these special addresses and
63 * vmalloc()-ed addresses never overlap.
64 *
65 * These 'compile-time allocated' memory buffers are
66 * fixed-size 4k pages (or larger if used with an increment
67 * higher than 1). Use set_fixmap(idx,phys) to associate
68 * physical memory with fixmap indices.
69 *
70 * TLB entries of such buffers will not be flushed across
71 * task switches.
72 */
73enum fixed_addresses {
74#ifdef CONFIG_X86_32
75 FIX_HOLE,
76 FIX_VDSO,
77#else
78 VSYSCALL_LAST_PAGE,
79 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
80 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
81 VVAR_PAGE,
82 VSYSCALL_HPET,
83#endif
84 FIX_DBGP_BASE,
85 FIX_EARLYCON_MEM_BASE,
86#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
87 FIX_OHCI1394_BASE,
88#endif
89#ifdef CONFIG_X86_LOCAL_APIC
90 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
91#endif
92#ifdef CONFIG_X86_IO_APIC
93 FIX_IO_APIC_BASE_0,
94 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
95#endif
96#ifdef CONFIG_X86_VISWS_APIC
97 FIX_CO_CPU, /* Cobalt timer */
98 FIX_CO_APIC, /* Cobalt APIC Redirection Table */
99 FIX_LI_PCIA, /* Lithium PCI Bridge A */
100 FIX_LI_PCIB, /* Lithium PCI Bridge B */
101#endif
102#ifdef CONFIG_X86_F00F_BUG
103 FIX_F00F_IDT, /* Virtual mapping for IDT */
104#endif
105#ifdef CONFIG_X86_CYCLONE_TIMER
106 FIX_CYCLONE_TIMER, /*cyclone timer register*/
107#endif
108#ifdef CONFIG_X86_32
109 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
110 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
111#ifdef CONFIG_PCI_MMCONFIG
112 FIX_PCIE_MCFG,
113#endif
114#endif
115#ifdef CONFIG_PARAVIRT
116 FIX_PARAVIRT_BOOTMAP,
117#endif
118 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
119 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
120#ifdef CONFIG_X86_INTEL_MID
121 FIX_LNW_VRTC,
122#endif
123 __end_of_permanent_fixed_addresses,
124
125 /*
126 * 256 temporary boot-time mappings, used by early_ioremap(),
127 * before ioremap() is functional.
128 *
129 * If necessary we round it up to the next 256 pages boundary so
130 * that we can have a single pgd entry and a single pte table:
131 */
132#define NR_FIX_BTMAPS 64
133#define FIX_BTMAPS_SLOTS 4
134#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
135 FIX_BTMAP_END =
136 (__end_of_permanent_fixed_addresses ^
137 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
138 -PTRS_PER_PTE
139 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
140 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
141 : __end_of_permanent_fixed_addresses,
142 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
143#ifdef CONFIG_X86_32
144 FIX_WP_TEST,
145#endif
146#ifdef CONFIG_INTEL_TXT
147 FIX_TBOOT_BASE,
148#endif
149 __end_of_fixed_addresses
150};
151
152
153extern void reserve_top_address(unsigned long reserve);
154
155#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
156#define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
157#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
158#define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
159
160extern int fixmaps_set;
161
162extern pte_t *kmap_pte;
163extern pgprot_t kmap_prot;
164extern pte_t *pkmap_page_table;
165
166void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
167void native_set_fixmap(enum fixed_addresses idx,
168 phys_addr_t phys, pgprot_t flags);
169
170#ifndef CONFIG_PARAVIRT
171static inline void __set_fixmap(enum fixed_addresses idx,
172 phys_addr_t phys, pgprot_t flags)
173{
174 native_set_fixmap(idx, phys, flags);
175}
176#endif
177
178#define set_fixmap(idx, phys) \
179 __set_fixmap(idx, phys, PAGE_KERNEL)
180
181/*
182 * Some hardware wants to get fixmapped without caching.
183 */
184#define set_fixmap_nocache(idx, phys) \
185 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
186
187#define clear_fixmap(idx) \
188 __set_fixmap(idx, 0, __pgprot(0))
189
190#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
191#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
192
193extern void __this_fixmap_does_not_exist(void);
194
195/*
196 * 'index to address' translation. If anyone tries to use the idx
197 * directly without translation, we catch the bug with a NULL-deference
198 * kernel oops. Illegal ranges of incoming indices are caught too.
199 */
200static __always_inline unsigned long fix_to_virt(const unsigned int idx)
201{
202 /*
203 * this branch gets completely eliminated after inlining,
204 * except when someone tries to use fixaddr indices in an
205 * illegal way. (such as mixing up address types or using
206 * out-of-range indices).
207 *
208 * If it doesn't get removed, the linker will complain
209 * loudly with a reasonably clear error message..
210 */
211 if (idx >= __end_of_fixed_addresses)
212 __this_fixmap_does_not_exist();
213
214 return __fix_to_virt(idx);
215}
216
217static inline unsigned long virt_to_fix(const unsigned long vaddr)
218{
219 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
220 return __virt_to_fix(vaddr);
221}
222
223/* Return an pointer with offset calculated */
224static __always_inline unsigned long
225__set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
226{
227 __set_fixmap(idx, phys, flags);
228 return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));
229}
230
231#define set_fixmap_offset(idx, phys) \
232 __set_fixmap_offset(idx, phys, PAGE_KERNEL)
233
234#define set_fixmap_offset_nocache(idx, phys) \
235 __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE)
236
237#endif /* !__ASSEMBLY__ */
238#endif /* _ASM_X86_FIXMAP_H */