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 #include <asm/kmap_size.h>
18 
19 /*
20  * Exposed to assembly code for setting up initial page tables. Cannot be
21  * calculated in assembly code (fixmap entries are an enum), but is sanity
22  * checked in the actual fixmap C code to make sure that the fixmap is
23  * covered fully.
24  */
25 #ifndef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
26 # define FIXMAP_PMD_NUM	2
27 #else
28 # define KM_PMDS	(KM_MAX_IDX * ((CONFIG_NR_CPUS + 511) / 512))
29 # define FIXMAP_PMD_NUM (KM_PMDS + 2)
30 #endif
31 /* fixmap starts downwards from the 507th entry in level2_fixmap_pgt */
32 #define FIXMAP_PMD_TOP	507
33 
34 #ifndef __ASSEMBLY__
35 #include <linux/kernel.h>
36 #include <asm/apicdef.h>
37 #include <asm/page.h>
38 #include <asm/pgtable_types.h>
39 #ifdef CONFIG_X86_32
40 #include <linux/threads.h>
41 #else
42 #include <uapi/asm/vsyscall.h>
43 #endif
44 
45 /*
46  * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
47  * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
48  * Because of this, FIXADDR_TOP x86 integration was left as later work.
49  */
50 #ifdef CONFIG_X86_32
51 /*
52  * Leave one empty page between vmalloc'ed areas and
53  * the start of the fixmap.
54  */
55 extern unsigned long __FIXADDR_TOP;
56 #define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
57 #else
58 #define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
59 			 PAGE_SIZE)
60 #endif
61 
62 /*
63  * Here we define all the compile-time 'special' virtual
64  * addresses. The point is to have a constant address at
65  * compile time, but to set the physical address only
66  * in the boot process.
67  * for x86_32: We allocate these special addresses
68  * from the end of virtual memory (0xfffff000) backwards.
69  * Also this lets us do fail-safe vmalloc(), we
70  * can guarantee that these special addresses and
71  * vmalloc()-ed addresses never overlap.
72  *
73  * These 'compile-time allocated' memory buffers are
74  * fixed-size 4k pages (or larger if used with an increment
75  * higher than 1). Use set_fixmap(idx,phys) to associate
76  * physical memory with fixmap indices.
77  *
78  * TLB entries of such buffers will not be flushed across
79  * task switches.
80  */
81 enum fixed_addresses {
82 #ifdef CONFIG_X86_32
83 	FIX_HOLE,
84 #else
85 #ifdef CONFIG_X86_VSYSCALL_EMULATION
86 	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
87 #endif
88 #endif
89 	FIX_DBGP_BASE,
90 	FIX_EARLYCON_MEM_BASE,
91 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
92 	FIX_OHCI1394_BASE,
93 #endif
94 #ifdef CONFIG_X86_LOCAL_APIC
95 	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
96 #endif
97 #ifdef CONFIG_X86_IO_APIC
98 	FIX_IO_APIC_BASE_0,
99 	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
100 #endif
101 #ifdef CONFIG_KMAP_LOCAL
102 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
103 	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
104 #ifdef CONFIG_PCI_MMCONFIG
105 	FIX_PCIE_MCFG,
106 #endif
107 #endif
108 #ifdef CONFIG_PARAVIRT_XXL
109 	FIX_PARAVIRT_BOOTMAP,
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 pmd 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 *pkmap_page_table;
158 
159 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
160 void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
161 		       phys_addr_t phys, pgprot_t flags);
162 
163 #ifndef CONFIG_PARAVIRT_XXL
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)164 static inline void __set_fixmap(enum fixed_addresses idx,
165 				phys_addr_t phys, pgprot_t flags)
166 {
167 	native_set_fixmap(idx, phys, flags);
168 }
169 #endif
170 
171 /*
172  * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
173  * supported for MMIO addresses, so make sure that the memory encryption
174  * mask is not part of the page attributes.
175  */
176 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
177 
178 /*
179  * Early memremap routines used for in-place encryption. The mappings created
180  * by these routines are intended to be used as temporary mappings.
181  */
182 void __init *early_memremap_encrypted(resource_size_t phys_addr,
183 				      unsigned long size);
184 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
185 					 unsigned long size);
186 void __init *early_memremap_decrypted(resource_size_t phys_addr,
187 				      unsigned long size);
188 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
189 					 unsigned long size);
190 
191 #include <asm-generic/fixmap.h>
192 
193 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
194 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
195 
196 void __early_set_fixmap(enum fixed_addresses idx,
197 			phys_addr_t phys, pgprot_t flags);
198 
199 #endif /* !__ASSEMBLY__ */
200 #endif /* _ASM_X86_FIXMAP_H */
201