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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#include <asm/pvclock.h>
23#ifdef CONFIG_X86_32
24#include <linux/threads.h>
25#include <asm/kmap_types.h>
26#else
27#include <asm/vsyscall.h>
28#endif
29
30/*
31 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
32 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
33 * Because of this, FIXADDR_TOP x86 integration was left as later work.
34 */
35#ifdef CONFIG_X86_32
36/* used by vmalloc.c, vsyscall.lds.S.
37 *
38 * Leave one empty page between vmalloc'ed areas and
39 * the start of the fixmap.
40 */
41extern unsigned long __FIXADDR_TOP;
42#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
43
44#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO)
45#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1)
46#else
47#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
48
49/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
50#define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
51#define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
52#endif
53
54
55/*
56 * Here we define all the compile-time 'special' virtual
57 * addresses. The point is to have a constant address at
58 * compile time, but to set the physical address only
59 * in the boot process.
60 * for x86_32: We allocate these special addresses
61 * from the end of virtual memory (0xfffff000) backwards.
62 * Also this lets us do fail-safe vmalloc(), we
63 * can guarantee that these special addresses and
64 * vmalloc()-ed addresses never overlap.
65 *
66 * These 'compile-time allocated' memory buffers are
67 * fixed-size 4k pages (or larger if used with an increment
68 * higher than 1). Use set_fixmap(idx,phys) to associate
69 * physical memory with fixmap indices.
70 *
71 * TLB entries of such buffers will not be flushed across
72 * task switches.
73 */
74enum fixed_addresses {
75#ifdef CONFIG_X86_32
76 FIX_HOLE,
77 FIX_VDSO,
78#else
79 VSYSCALL_LAST_PAGE,
80 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
81 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
82 VVAR_PAGE,
83 VSYSCALL_HPET,
84#endif
85#ifdef CONFIG_PARAVIRT_CLOCK
86 PVCLOCK_FIXMAP_BEGIN,
87 PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
88#endif
89 FIX_DBGP_BASE,
90 FIX_EARLYCON_MEM_BASE,
91#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
92 FIX_OHCI1394_BASE,
93#endif
94#ifdef CONFIG_X86_LOCAL_APIC
95 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
96#endif
97#ifdef CONFIG_X86_IO_APIC
98 FIX_IO_APIC_BASE_0,
99 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
100#endif
101#ifdef CONFIG_X86_VISWS_APIC
102 FIX_CO_CPU, /* Cobalt timer */
103 FIX_CO_APIC, /* Cobalt APIC Redirection Table */
104 FIX_LI_PCIA, /* Lithium PCI Bridge A */
105 FIX_LI_PCIB, /* Lithium PCI Bridge B */
106#endif
107#ifdef CONFIG_X86_F00F_BUG
108 FIX_F00F_IDT, /* Virtual mapping for IDT */
109#endif
110#ifdef CONFIG_X86_CYCLONE_TIMER
111 FIX_CYCLONE_TIMER, /*cyclone timer register*/
112#endif
113#ifdef CONFIG_X86_32
114 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
115 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
116#ifdef CONFIG_PCI_MMCONFIG
117 FIX_PCIE_MCFG,
118#endif
119#endif
120#ifdef CONFIG_PARAVIRT
121 FIX_PARAVIRT_BOOTMAP,
122#endif
123 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
124 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
125#ifdef CONFIG_X86_INTEL_MID
126 FIX_LNW_VRTC,
127#endif
128 __end_of_permanent_fixed_addresses,
129
130 /*
131 * 256 temporary boot-time mappings, used by early_ioremap(),
132 * before ioremap() is functional.
133 *
134 * If necessary we round it up to the next 256 pages boundary so
135 * that we can have a single pgd entry and a single pte table:
136 */
137#define NR_FIX_BTMAPS 64
138#define FIX_BTMAPS_SLOTS 4
139#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
140 FIX_BTMAP_END =
141 (__end_of_permanent_fixed_addresses ^
142 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
143 -PTRS_PER_PTE
144 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
145 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
146 : __end_of_permanent_fixed_addresses,
147 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
148#ifdef CONFIG_X86_32
149 FIX_WP_TEST,
150#endif
151#ifdef CONFIG_INTEL_TXT
152 FIX_TBOOT_BASE,
153#endif
154 __end_of_fixed_addresses
155};
156
157
158extern void reserve_top_address(unsigned long reserve);
159
160#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
161#define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
162#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
163#define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
164
165extern int fixmaps_set;
166
167extern pte_t *kmap_pte;
168extern pgprot_t kmap_prot;
169extern pte_t *pkmap_page_table;
170
171void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
172void native_set_fixmap(enum fixed_addresses idx,
173 phys_addr_t phys, pgprot_t flags);
174
175#ifndef CONFIG_PARAVIRT
176static inline void __set_fixmap(enum fixed_addresses idx,
177 phys_addr_t phys, pgprot_t flags)
178{
179 native_set_fixmap(idx, phys, flags);
180}
181#endif
182
183#define set_fixmap(idx, phys) \
184 __set_fixmap(idx, phys, PAGE_KERNEL)
185
186/*
187 * Some hardware wants to get fixmapped without caching.
188 */
189#define set_fixmap_nocache(idx, phys) \
190 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
191
192#define clear_fixmap(idx) \
193 __set_fixmap(idx, 0, __pgprot(0))
194
195#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
196#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
197
198extern void __this_fixmap_does_not_exist(void);
199
200/*
201 * 'index to address' translation. If anyone tries to use the idx
202 * directly without translation, we catch the bug with a NULL-deference
203 * kernel oops. Illegal ranges of incoming indices are caught too.
204 */
205static __always_inline unsigned long fix_to_virt(const unsigned int idx)
206{
207 /*
208 * this branch gets completely eliminated after inlining,
209 * except when someone tries to use fixaddr indices in an
210 * illegal way. (such as mixing up address types or using
211 * out-of-range indices).
212 *
213 * If it doesn't get removed, the linker will complain
214 * loudly with a reasonably clear error message..
215 */
216 if (idx >= __end_of_fixed_addresses)
217 __this_fixmap_does_not_exist();
218
219 return __fix_to_virt(idx);
220}
221
222static inline unsigned long virt_to_fix(const unsigned long vaddr)
223{
224 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
225 return __virt_to_fix(vaddr);
226}
227
228/* Return an pointer with offset calculated */
229static __always_inline unsigned long
230__set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
231{
232 __set_fixmap(idx, phys, flags);
233 return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));
234}
235
236#define set_fixmap_offset(idx, phys) \
237 __set_fixmap_offset(idx, phys, PAGE_KERNEL)
238
239#define set_fixmap_offset_nocache(idx, phys) \
240 __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE)
241
242#endif /* !__ASSEMBLY__ */
243#endif /* _ASM_X86_FIXMAP_H */