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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 <uapi/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  */
41 extern unsigned long __FIXADDR_TOP;
42 #define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
43 #else
44 #define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
45 			 PAGE_SIZE)
46 #endif
47 
48 
49 /*
50  * Here we define all the compile-time 'special' virtual
51  * addresses. The point is to have a constant address at
52  * compile time, but to set the physical address only
53  * in the boot process.
54  * for x86_32: We allocate these special addresses
55  * from the end of virtual memory (0xfffff000) backwards.
56  * Also this lets us do fail-safe vmalloc(), we
57  * can guarantee that these special addresses and
58  * vmalloc()-ed addresses never overlap.
59  *
60  * These 'compile-time allocated' memory buffers are
61  * fixed-size 4k pages (or larger if used with an increment
62  * higher than 1). Use set_fixmap(idx,phys) to associate
63  * physical memory with fixmap indices.
64  *
65  * TLB entries of such buffers will not be flushed across
66  * task switches.
67  */
68 enum fixed_addresses {
69 #ifdef CONFIG_X86_32
70 	FIX_HOLE,
71 #else
72 #ifdef CONFIG_X86_VSYSCALL_EMULATION
73 	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
74 #endif
75 #ifdef CONFIG_PARAVIRT_CLOCK
76 	PVCLOCK_FIXMAP_BEGIN,
77 	PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
78 #endif
79 #endif
80 	FIX_DBGP_BASE,
81 	FIX_EARLYCON_MEM_BASE,
82 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
83 	FIX_OHCI1394_BASE,
84 #endif
85 #ifdef CONFIG_X86_LOCAL_APIC
86 	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
87 #endif
88 #ifdef CONFIG_X86_IO_APIC
89 	FIX_IO_APIC_BASE_0,
90 	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
91 #endif
92 	FIX_RO_IDT,	/* Virtual mapping for read-only IDT */
93 #ifdef CONFIG_X86_32
94 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
95 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
96 #ifdef CONFIG_PCI_MMCONFIG
97 	FIX_PCIE_MCFG,
98 #endif
99 #endif
100 #ifdef CONFIG_PARAVIRT
101 	FIX_PARAVIRT_BOOTMAP,
102 #endif
103 	FIX_TEXT_POKE1,	/* reserve 2 pages for text_poke() */
104 	FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
105 #ifdef	CONFIG_X86_INTEL_MID
106 	FIX_LNW_VRTC,
107 #endif
108 	__end_of_permanent_fixed_addresses,
109 
110 	/*
111 	 * 512 temporary boot-time mappings, used by early_ioremap(),
112 	 * before ioremap() is functional.
113 	 *
114 	 * If necessary we round it up to the next 512 pages boundary so
115 	 * that we can have a single pgd entry and a single pte table:
116 	 */
117 #define NR_FIX_BTMAPS		64
118 #define FIX_BTMAPS_SLOTS	8
119 #define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
120 	FIX_BTMAP_END =
121 	 (__end_of_permanent_fixed_addresses ^
122 	  (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
123 	 -PTRS_PER_PTE
124 	 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
125 	   (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
126 	 : __end_of_permanent_fixed_addresses,
127 	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
128 #ifdef CONFIG_X86_32
129 	FIX_WP_TEST,
130 #endif
131 #ifdef CONFIG_INTEL_TXT
132 	FIX_TBOOT_BASE,
133 #endif
134 	__end_of_fixed_addresses
135 };
136 
137 
138 extern void reserve_top_address(unsigned long reserve);
139 
140 #define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
141 #define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
142 
143 extern int fixmaps_set;
144 
145 extern pte_t *kmap_pte;
146 extern pgprot_t kmap_prot;
147 extern pte_t *pkmap_page_table;
148 
149 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
150 void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
151 		       phys_addr_t phys, pgprot_t flags);
152 
153 #ifndef CONFIG_PARAVIRT
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)154 static inline void __set_fixmap(enum fixed_addresses idx,
155 				phys_addr_t phys, pgprot_t flags)
156 {
157 	native_set_fixmap(idx, phys, flags);
158 }
159 #endif
160 
161 #include <asm-generic/fixmap.h>
162 
163 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
164 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
165 
166 void __early_set_fixmap(enum fixed_addresses idx,
167 			phys_addr_t phys, pgprot_t flags);
168 
169 #endif /* !__ASSEMBLY__ */
170 #endif /* _ASM_X86_FIXMAP_H */
171