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
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
14 #ifndef _ASM_X86_FIXMAP_H
15 #define _ASM_X86_FIXMAP_H
18 #include <linux/kernel.h>
20 #include <asm/apicdef.h>
23 #include <linux/threads.h>
24 #include <asm/kmap_types.h>
26 #include <asm/vsyscall.h>
33 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
34 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
35 * Because of this, FIXADDR_TOP x86 integration was left as later work.
38 /* used by vmalloc.c, vsyscall.lds.S.
40 * Leave one empty page between vmalloc'ed areas and
41 * the start of the fixmap.
43 extern unsigned long __FIXADDR_TOP;
44 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
46 #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO)
47 #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1)
49 #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
51 /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
52 #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
53 #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
58 * Here we define all the compile-time 'special' virtual
59 * addresses. The point is to have a constant address at
60 * compile time, but to set the physical address only
61 * in the boot process.
62 * for x86_32: We allocate these special addresses
63 * from the end of virtual memory (0xfffff000) backwards.
64 * Also this lets us do fail-safe vmalloc(), we
65 * can guarantee that these special addresses and
66 * vmalloc()-ed addresses never overlap.
68 * These 'compile-time allocated' memory buffers are
69 * fixed-size 4k pages (or larger if used with an increment
70 * higher than 1). Use set_fixmap(idx,phys) to associate
71 * physical memory with fixmap indices.
73 * TLB entries of such buffers will not be flushed across
76 enum fixed_addresses {
82 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
83 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
87 FIX_EARLYCON_MEM_BASE,
88 #ifdef CONFIG_X86_LOCAL_APIC
89 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
91 #ifdef CONFIG_X86_IO_APIC
93 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
97 FIX_EFI_IO_MAP_LAST_PAGE,
98 FIX_EFI_IO_MAP_FIRST_PAGE = FIX_EFI_IO_MAP_LAST_PAGE
99 + MAX_EFI_IO_PAGES - 1,
102 #ifdef CONFIG_X86_VISWS_APIC
103 FIX_CO_CPU, /* Cobalt timer */
104 FIX_CO_APIC, /* Cobalt APIC Redirection Table */
105 FIX_LI_PCIA, /* Lithium PCI Bridge A */
106 FIX_LI_PCIB, /* Lithium PCI Bridge B */
108 #ifdef CONFIG_X86_F00F_BUG
109 FIX_F00F_IDT, /* Virtual mapping for IDT */
111 #ifdef CONFIG_X86_CYCLONE_TIMER
112 FIX_CYCLONE_TIMER, /*cyclone timer register*/
115 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
116 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
117 #ifdef CONFIG_PCI_MMCONFIG
121 #ifdef CONFIG_PARAVIRT
122 FIX_PARAVIRT_BOOTMAP,
124 __end_of_permanent_fixed_addresses,
125 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
129 * 256 temporary boot-time mappings, used by early_ioremap(),
130 * before ioremap() is functional.
132 * We round it up to the next 256 pages boundary so that we
133 * can have a single pgd entry and a single pte table:
135 #define NR_FIX_BTMAPS 64
136 #define FIX_BTMAPS_SLOTS 4
137 FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 256 -
138 (__end_of_permanent_fixed_addresses & 255),
139 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_SLOTS - 1,
143 __end_of_fixed_addresses
147 extern void reserve_top_address(unsigned long reserve);
149 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
150 #define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
151 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
152 #define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
154 extern int fixmaps_set;
156 extern pte_t *kmap_pte;
157 extern pgprot_t kmap_prot;
158 extern pte_t *pkmap_page_table;
160 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
161 void native_set_fixmap(enum fixed_addresses idx,
162 unsigned long phys, pgprot_t flags);
164 #ifndef CONFIG_PARAVIRT
165 static inline void __set_fixmap(enum fixed_addresses idx,
166 unsigned long phys, pgprot_t flags)
168 native_set_fixmap(idx, phys, flags);
172 #define set_fixmap(idx, phys) \
173 __set_fixmap(idx, phys, PAGE_KERNEL)
176 * Some hardware wants to get fixmapped without caching.
178 #define set_fixmap_nocache(idx, phys) \
179 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
181 #define clear_fixmap(idx) \
182 __set_fixmap(idx, 0, __pgprot(0))
184 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
185 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
187 extern void __this_fixmap_does_not_exist(void);
190 * 'index to address' translation. If anyone tries to use the idx
191 * directly without translation, we catch the bug with a NULL-deference
192 * kernel oops. Illegal ranges of incoming indices are caught too.
194 static __always_inline unsigned long fix_to_virt(const unsigned int idx)
197 * this branch gets completely eliminated after inlining,
198 * except when someone tries to use fixaddr indices in an
199 * illegal way. (such as mixing up address types or using
200 * out-of-range indices).
202 * If it doesn't get removed, the linker will complain
203 * loudly with a reasonably clear error message..
205 if (idx >= __end_of_fixed_addresses)
206 __this_fixmap_does_not_exist();
208 return __fix_to_virt(idx);
211 static inline unsigned long virt_to_fix(const unsigned long vaddr)
213 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
214 return __virt_to_fix(vaddr);
216 #endif /* !__ASSEMBLY__ */
217 #endif /* _ASM_X86_FIXMAP_H */