xref: /openbmc/linux/arch/x86/include/asm/fixmap.h (revision 0c874100)
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 /* used by vmalloc.c, vsyscall.lds.S.
46  *
47  * Leave one empty page between vmalloc'ed areas and
48  * the start of the fixmap.
49  */
50 extern unsigned long __FIXADDR_TOP;
51 #define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
52 #else
53 #define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
54 			 PAGE_SIZE)
55 #endif
56 
57 /*
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.
67  *
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.
72  *
73  * TLB entries of such buffers will not be flushed across
74  * task switches.
75  */
76 enum fixed_addresses {
77 #ifdef CONFIG_X86_32
78 	FIX_HOLE,
79 #else
80 #ifdef CONFIG_X86_VSYSCALL_EMULATION
81 	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
82 #endif
83 #endif
84 	FIX_DBGP_BASE,
85 	FIX_EARLYCON_MEM_BASE,
86 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
87 	FIX_OHCI1394_BASE,
88 #endif
89 #ifdef CONFIG_X86_LOCAL_APIC
90 	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
91 #endif
92 #ifdef CONFIG_X86_IO_APIC
93 	FIX_IO_APIC_BASE_0,
94 	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
95 #endif
96 #ifdef CONFIG_X86_32
97 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
98 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
99 #ifdef CONFIG_PCI_MMCONFIG
100 	FIX_PCIE_MCFG,
101 #endif
102 #endif
103 #ifdef CONFIG_PARAVIRT
104 	FIX_PARAVIRT_BOOTMAP,
105 #endif
106 	FIX_TEXT_POKE1,	/* reserve 2 pages for text_poke() */
107 	FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
108 #ifdef	CONFIG_X86_INTEL_MID
109 	FIX_LNW_VRTC,
110 #endif
111 
112 #ifdef CONFIG_ACPI_APEI_GHES
113 	/* Used for GHES mapping from assorted contexts */
114 	FIX_APEI_GHES_IRQ,
115 	FIX_APEI_GHES_NMI,
116 #endif
117 
118 	__end_of_permanent_fixed_addresses,
119 
120 	/*
121 	 * 512 temporary boot-time mappings, used by early_ioremap(),
122 	 * before ioremap() is functional.
123 	 *
124 	 * If necessary we round it up to the next 512 pages boundary so
125 	 * that we can have a single pgd entry and a single pte table:
126 	 */
127 #define NR_FIX_BTMAPS		64
128 #define FIX_BTMAPS_SLOTS	8
129 #define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
130 	FIX_BTMAP_END =
131 	 (__end_of_permanent_fixed_addresses ^
132 	  (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
133 	 -PTRS_PER_PTE
134 	 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
135 	   (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
136 	 : __end_of_permanent_fixed_addresses,
137 	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
138 #ifdef CONFIG_X86_32
139 	FIX_WP_TEST,
140 #endif
141 #ifdef CONFIG_INTEL_TXT
142 	FIX_TBOOT_BASE,
143 #endif
144 	__end_of_fixed_addresses
145 };
146 
147 
148 extern void reserve_top_address(unsigned long reserve);
149 
150 #define FIXADDR_SIZE		(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
151 #define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
152 #define FIXADDR_TOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
153 #define FIXADDR_TOT_START	(FIXADDR_TOP - FIXADDR_TOT_SIZE)
154 
155 extern int fixmaps_set;
156 
157 extern pte_t *kmap_pte;
158 #define kmap_prot PAGE_KERNEL
159 extern pte_t *pkmap_page_table;
160 
161 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
162 void native_set_fixmap(enum fixed_addresses idx,
163 		       phys_addr_t phys, pgprot_t flags);
164 
165 #ifndef CONFIG_PARAVIRT_XXL
166 static inline void __set_fixmap(enum fixed_addresses idx,
167 				phys_addr_t phys, pgprot_t flags)
168 {
169 	native_set_fixmap(idx, phys, flags);
170 }
171 #endif
172 
173 /*
174  * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
175  * supported for MMIO addresses, so make sure that the memory encryption
176  * mask is not part of the page attributes.
177  */
178 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
179 
180 /*
181  * Early memremap routines used for in-place encryption. The mappings created
182  * by these routines are intended to be used as temporary mappings.
183  */
184 void __init *early_memremap_encrypted(resource_size_t phys_addr,
185 				      unsigned long size);
186 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
187 					 unsigned long size);
188 void __init *early_memremap_decrypted(resource_size_t phys_addr,
189 				      unsigned long size);
190 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
191 					 unsigned long size);
192 
193 #include <asm-generic/fixmap.h>
194 
195 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
196 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
197 
198 void __early_set_fixmap(enum fixed_addresses idx,
199 			phys_addr_t phys, pgprot_t flags);
200 
201 #endif /* !__ASSEMBLY__ */
202 #endif /* _ASM_X86_FIXMAP_H */
203