xref: /linux/arch/x86/include/asm/fixmap.h (revision d198b34f3855eee2571dda03eea75a09c7c31480)
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 /*
18  * Exposed to assembly code for setting up initial page tables. Cannot be
19  * calculated in assembly code (fixmap entries are an enum), but is sanity
20  * checked in the actual fixmap C code to make sure that the fixmap is
21  * covered fully.
22  */
23 #define FIXMAP_PMD_NUM	2
24 /* fixmap starts downwards from the 507th entry in level2_fixmap_pgt */
25 #define FIXMAP_PMD_TOP	507
26 
27 #ifndef __ASSEMBLY__
28 #include <linux/kernel.h>
29 #include <asm/acpi.h>
30 #include <asm/apicdef.h>
31 #include <asm/page.h>
32 #ifdef CONFIG_X86_32
33 #include <linux/threads.h>
34 #include <asm/kmap_types.h>
35 #else
36 #include <uapi/asm/vsyscall.h>
37 #endif
38 
39 /*
40  * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
41  * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
42  * Because of this, FIXADDR_TOP x86 integration was left as later work.
43  */
44 #ifdef CONFIG_X86_32
45 /*
46  * Leave one empty page between vmalloc'ed areas and
47  * the start of the fixmap.
48  */
49 extern unsigned long __FIXADDR_TOP;
50 #define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
51 #else
52 #define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
53 			 PAGE_SIZE)
54 #endif
55 
56 /*
57  * Here we define all the compile-time 'special' virtual
58  * addresses. The point is to have a constant address at
59  * compile time, but to set the physical address only
60  * in the boot process.
61  * for x86_32: We allocate these special addresses
62  * from the end of virtual memory (0xfffff000) backwards.
63  * Also this lets us do fail-safe vmalloc(), we
64  * can guarantee that these special addresses and
65  * vmalloc()-ed addresses never overlap.
66  *
67  * These 'compile-time allocated' memory buffers are
68  * fixed-size 4k pages (or larger if used with an increment
69  * higher than 1). Use set_fixmap(idx,phys) to associate
70  * physical memory with fixmap indices.
71  *
72  * TLB entries of such buffers will not be flushed across
73  * task switches.
74  */
75 enum fixed_addresses {
76 #ifdef CONFIG_X86_32
77 	FIX_HOLE,
78 #else
79 #ifdef CONFIG_X86_VSYSCALL_EMULATION
80 	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
81 #endif
82 #endif
83 	FIX_DBGP_BASE,
84 	FIX_EARLYCON_MEM_BASE,
85 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
86 	FIX_OHCI1394_BASE,
87 #endif
88 #ifdef CONFIG_X86_LOCAL_APIC
89 	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
90 #endif
91 #ifdef CONFIG_X86_IO_APIC
92 	FIX_IO_APIC_BASE_0,
93 	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
94 #endif
95 #ifdef CONFIG_X86_32
96 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
97 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
98 #ifdef CONFIG_PCI_MMCONFIG
99 	FIX_PCIE_MCFG,
100 #endif
101 #endif
102 #ifdef CONFIG_PARAVIRT
103 	FIX_PARAVIRT_BOOTMAP,
104 #endif
105 #ifdef	CONFIG_X86_INTEL_MID
106 	FIX_LNW_VRTC,
107 #endif
108 
109 #ifdef CONFIG_ACPI_APEI_GHES
110 	/* Used for GHES mapping from assorted contexts */
111 	FIX_APEI_GHES_IRQ,
112 	FIX_APEI_GHES_NMI,
113 #endif
114 
115 	__end_of_permanent_fixed_addresses,
116 
117 	/*
118 	 * 512 temporary boot-time mappings, used by early_ioremap(),
119 	 * before ioremap() is functional.
120 	 *
121 	 * If necessary we round it up to the next 512 pages boundary so
122 	 * that we can have a single pmd entry and a single pte table:
123 	 */
124 #define NR_FIX_BTMAPS		64
125 #define FIX_BTMAPS_SLOTS	8
126 #define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
127 	FIX_BTMAP_END =
128 	 (__end_of_permanent_fixed_addresses ^
129 	  (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
130 	 -PTRS_PER_PTE
131 	 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
132 	   (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
133 	 : __end_of_permanent_fixed_addresses,
134 	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
135 #ifdef CONFIG_X86_32
136 	FIX_WP_TEST,
137 #endif
138 #ifdef CONFIG_INTEL_TXT
139 	FIX_TBOOT_BASE,
140 #endif
141 	__end_of_fixed_addresses
142 };
143 
144 
145 extern void reserve_top_address(unsigned long reserve);
146 
147 #define FIXADDR_SIZE		(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
148 #define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
149 #define FIXADDR_TOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
150 #define FIXADDR_TOT_START	(FIXADDR_TOP - FIXADDR_TOT_SIZE)
151 
152 extern int fixmaps_set;
153 
154 extern pte_t *kmap_pte;
155 #define kmap_prot PAGE_KERNEL
156 extern pte_t *pkmap_page_table;
157 
158 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
159 void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
160 		       phys_addr_t phys, pgprot_t flags);
161 
162 #ifndef CONFIG_PARAVIRT_XXL
163 static inline void __set_fixmap(enum fixed_addresses idx,
164 				phys_addr_t phys, pgprot_t flags)
165 {
166 	native_set_fixmap(idx, phys, flags);
167 }
168 #endif
169 
170 /*
171  * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
172  * supported for MMIO addresses, so make sure that the memory encryption
173  * mask is not part of the page attributes.
174  */
175 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
176 
177 /*
178  * Early memremap routines used for in-place encryption. The mappings created
179  * by these routines are intended to be used as temporary mappings.
180  */
181 void __init *early_memremap_encrypted(resource_size_t phys_addr,
182 				      unsigned long size);
183 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
184 					 unsigned long size);
185 void __init *early_memremap_decrypted(resource_size_t phys_addr,
186 				      unsigned long size);
187 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
188 					 unsigned long size);
189 
190 #include <asm-generic/fixmap.h>
191 
192 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
193 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
194 
195 void __early_set_fixmap(enum fixed_addresses idx,
196 			phys_addr_t phys, pgprot_t flags);
197 
198 #endif /* !__ASSEMBLY__ */
199 #endif /* _ASM_X86_FIXMAP_H */
200