2 * fixmap.h: compile-time virtual memory allocation
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
8 * Copyright (C) 1998 Ingo Molnar
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
14 #ifndef _ASM_X86_FIXMAP_H
15 #define _ASM_X86_FIXMAP_H
18 #include <linux/kernel.h>
20 #include <asm/apicdef.h>
23 #include <linux/threads.h>
24 #include <asm/kmap_types.h>
26 #include <uapi/asm/vsyscall.h>
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.
35 /* used by vmalloc.c, vsyscall.lds.S.
37 * Leave one empty page between vmalloc'ed areas and
38 * the start of the fixmap.
40 extern unsigned long __FIXADDR_TOP;
41 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
43 #define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
48 * cpu_entry_area is a percpu region in the fixmap that contains things
49 * needed by the CPU and early entry/exit code. Real types aren't used
50 * for all fields here to avoid circular header dependencies.
52 * Every field is a virtual alias of some other allocated backing store.
53 * There is no direct allocation of a struct cpu_entry_area.
55 struct cpu_entry_area {
59 * The GDT is just below cpu_tss and thus serves (on x86_64) as a
60 * a read-only guard page for the SYSENTER stack at the bottom
63 struct tss_struct tss;
65 char entry_trampoline[PAGE_SIZE];
69 * Exception stacks used for IST entries.
71 * In the future, this should have a separate slot for each stack
72 * with guard pages between them.
74 char exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ];
78 #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE)
80 extern void setup_cpu_entry_areas(void);
83 * Here we define all the compile-time 'special' virtual
84 * addresses. The point is to have a constant address at
85 * compile time, but to set the physical address only
86 * in the boot process.
87 * for x86_32: We allocate these special addresses
88 * from the end of virtual memory (0xfffff000) backwards.
89 * Also this lets us do fail-safe vmalloc(), we
90 * can guarantee that these special addresses and
91 * vmalloc()-ed addresses never overlap.
93 * These 'compile-time allocated' memory buffers are
94 * fixed-size 4k pages (or larger if used with an increment
95 * higher than 1). Use set_fixmap(idx,phys) to associate
96 * physical memory with fixmap indices.
98 * TLB entries of such buffers will not be flushed across
101 enum fixed_addresses {
105 #ifdef CONFIG_X86_VSYSCALL_EMULATION
106 VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
110 FIX_EARLYCON_MEM_BASE,
111 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
114 #ifdef CONFIG_X86_LOCAL_APIC
115 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
117 #ifdef CONFIG_X86_IO_APIC
119 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
121 FIX_RO_IDT, /* Virtual mapping for read-only IDT */
123 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
124 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
125 #ifdef CONFIG_PCI_MMCONFIG
129 #ifdef CONFIG_PARAVIRT
130 FIX_PARAVIRT_BOOTMAP,
132 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
133 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
134 #ifdef CONFIG_X86_INTEL_MID
137 /* Fixmap entries to remap the GDTs, one per processor. */
138 FIX_CPU_ENTRY_AREA_TOP,
139 FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1,
141 #ifdef CONFIG_ACPI_APEI_GHES
142 /* Used for GHES mapping from assorted contexts */
147 __end_of_permanent_fixed_addresses,
150 * 512 temporary boot-time mappings, used by early_ioremap(),
151 * before ioremap() is functional.
153 * If necessary we round it up to the next 512 pages boundary so
154 * that we can have a single pgd entry and a single pte table:
156 #define NR_FIX_BTMAPS 64
157 #define FIX_BTMAPS_SLOTS 8
158 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
160 (__end_of_permanent_fixed_addresses ^
161 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
163 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
164 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
165 : __end_of_permanent_fixed_addresses,
166 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
170 #ifdef CONFIG_INTEL_TXT
173 __end_of_fixed_addresses
177 extern void reserve_top_address(unsigned long reserve);
179 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
180 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
182 extern int fixmaps_set;
184 extern pte_t *kmap_pte;
185 #define kmap_prot PAGE_KERNEL
186 extern pte_t *pkmap_page_table;
188 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
189 void native_set_fixmap(enum fixed_addresses idx,
190 phys_addr_t phys, pgprot_t flags);
192 #ifndef CONFIG_PARAVIRT
193 static inline void __set_fixmap(enum fixed_addresses idx,
194 phys_addr_t phys, pgprot_t flags)
196 native_set_fixmap(idx, phys, flags);
201 * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
202 * supported for MMIO addresses, so make sure that the memory encryption
203 * mask is not part of the page attributes.
205 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
208 * Early memremap routines used for in-place encryption. The mappings created
209 * by these routines are intended to be used as temporary mappings.
211 void __init *early_memremap_encrypted(resource_size_t phys_addr,
213 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
215 void __init *early_memremap_decrypted(resource_size_t phys_addr,
217 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
220 #include <asm-generic/fixmap.h>
222 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
223 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
225 void __early_set_fixmap(enum fixed_addresses idx,
226 phys_addr_t phys, pgprot_t flags);
228 static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page)
230 BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
232 return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page;
235 #define __get_cpu_entry_area_offset_index(cpu, offset) ({ \
236 BUILD_BUG_ON(offset % PAGE_SIZE != 0); \
237 __get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \
240 #define get_cpu_entry_area_index(cpu, field) \
241 __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field))
243 static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
245 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
248 #endif /* !__ASSEMBLY__ */
249 #endif /* _ASM_X86_FIXMAP_H */