xref: /linux/arch/x86/include/asm/fixmap.h (revision fdc0269e)
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 <uapi/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  */
40 extern unsigned long __FIXADDR_TOP;
41 #define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
42 #else
43 #define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
44 			 PAGE_SIZE)
45 #endif
46 
47 /*
48  * Here we define all the compile-time 'special' virtual
49  * addresses. The point is to have a constant address at
50  * compile time, but to set the physical address only
51  * in the boot process.
52  * for x86_32: We allocate these special addresses
53  * from the end of virtual memory (0xfffff000) backwards.
54  * Also this lets us do fail-safe vmalloc(), we
55  * can guarantee that these special addresses and
56  * vmalloc()-ed addresses never overlap.
57  *
58  * These 'compile-time allocated' memory buffers are
59  * fixed-size 4k pages (or larger if used with an increment
60  * higher than 1). Use set_fixmap(idx,phys) to associate
61  * physical memory with fixmap indices.
62  *
63  * TLB entries of such buffers will not be flushed across
64  * task switches.
65  */
66 enum fixed_addresses {
67 #ifdef CONFIG_X86_32
68 	FIX_HOLE,
69 #else
70 #ifdef CONFIG_X86_VSYSCALL_EMULATION
71 	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
72 #endif
73 #endif
74 	FIX_DBGP_BASE,
75 	FIX_EARLYCON_MEM_BASE,
76 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
77 	FIX_OHCI1394_BASE,
78 #endif
79 #ifdef CONFIG_X86_LOCAL_APIC
80 	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
81 #endif
82 #ifdef CONFIG_X86_IO_APIC
83 	FIX_IO_APIC_BASE_0,
84 	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
85 #endif
86 #ifdef CONFIG_X86_32
87 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
88 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
89 #ifdef CONFIG_PCI_MMCONFIG
90 	FIX_PCIE_MCFG,
91 #endif
92 #endif
93 #ifdef CONFIG_PARAVIRT
94 	FIX_PARAVIRT_BOOTMAP,
95 #endif
96 	FIX_TEXT_POKE1,	/* reserve 2 pages for text_poke() */
97 	FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
98 #ifdef	CONFIG_X86_INTEL_MID
99 	FIX_LNW_VRTC,
100 #endif
101 
102 #ifdef CONFIG_ACPI_APEI_GHES
103 	/* Used for GHES mapping from assorted contexts */
104 	FIX_APEI_GHES_IRQ,
105 	FIX_APEI_GHES_NMI,
106 #endif
107 
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 #define FIXADDR_TOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
143 #define FIXADDR_TOT_START	(FIXADDR_TOP - FIXADDR_TOT_SIZE)
144 
145 extern int fixmaps_set;
146 
147 extern pte_t *kmap_pte;
148 #define kmap_prot PAGE_KERNEL
149 extern pte_t *pkmap_page_table;
150 
151 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
152 void native_set_fixmap(enum fixed_addresses idx,
153 		       phys_addr_t phys, pgprot_t flags);
154 
155 #ifndef CONFIG_PARAVIRT_XXL
156 static inline void __set_fixmap(enum fixed_addresses idx,
157 				phys_addr_t phys, pgprot_t flags)
158 {
159 	native_set_fixmap(idx, phys, flags);
160 }
161 #endif
162 
163 /*
164  * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
165  * supported for MMIO addresses, so make sure that the memory encryption
166  * mask is not part of the page attributes.
167  */
168 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
169 
170 /*
171  * Early memremap routines used for in-place encryption. The mappings created
172  * by these routines are intended to be used as temporary mappings.
173  */
174 void __init *early_memremap_encrypted(resource_size_t phys_addr,
175 				      unsigned long size);
176 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
177 					 unsigned long size);
178 void __init *early_memremap_decrypted(resource_size_t phys_addr,
179 				      unsigned long size);
180 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
181 					 unsigned long size);
182 
183 #include <asm-generic/fixmap.h>
184 
185 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
186 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
187 
188 void __early_set_fixmap(enum fixed_addresses idx,
189 			phys_addr_t phys, pgprot_t flags);
190 
191 #endif /* !__ASSEMBLY__ */
192 #endif /* _ASM_X86_FIXMAP_H */
193