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 SYSENTER_stack and thus serves (on x86_64) as
60 * a a read-only guard page.
62 struct SYSENTER_stack_page SYSENTER_stack_page;
65 * On x86_64, the TSS is mapped RO. On x86_32, it's mapped RW because
66 * we need task switches to work, and task switches write to the TSS.
68 struct tss_struct tss;
70 char entry_trampoline[PAGE_SIZE];
74 * Exception stacks used for IST entries.
76 * In the future, this should have a separate slot for each stack
77 * with guard pages between them.
79 char exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ];
83 #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE)
85 extern void setup_cpu_entry_areas(void);
88 * Here we define all the compile-time 'special' virtual
89 * addresses. The point is to have a constant address at
90 * compile time, but to set the physical address only
91 * in the boot process.
92 * for x86_32: We allocate these special addresses
93 * from the end of virtual memory (0xfffff000) backwards.
94 * Also this lets us do fail-safe vmalloc(), we
95 * can guarantee that these special addresses and
96 * vmalloc()-ed addresses never overlap.
98 * These 'compile-time allocated' memory buffers are
99 * fixed-size 4k pages (or larger if used with an increment
100 * higher than 1). Use set_fixmap(idx,phys) to associate
101 * physical memory with fixmap indices.
103 * TLB entries of such buffers will not be flushed across
106 enum fixed_addresses {
110 #ifdef CONFIG_X86_VSYSCALL_EMULATION
111 VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
115 FIX_EARLYCON_MEM_BASE,
116 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
119 #ifdef CONFIG_X86_LOCAL_APIC
120 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
122 #ifdef CONFIG_X86_IO_APIC
124 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
126 FIX_RO_IDT, /* Virtual mapping for read-only IDT */
128 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
129 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
130 #ifdef CONFIG_PCI_MMCONFIG
134 #ifdef CONFIG_PARAVIRT
135 FIX_PARAVIRT_BOOTMAP,
137 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
138 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
139 #ifdef CONFIG_X86_INTEL_MID
142 /* Fixmap entries to remap the GDTs, one per processor. */
143 FIX_CPU_ENTRY_AREA_TOP,
144 FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1,
146 #ifdef CONFIG_ACPI_APEI_GHES
147 /* Used for GHES mapping from assorted contexts */
152 __end_of_permanent_fixed_addresses,
155 * 512 temporary boot-time mappings, used by early_ioremap(),
156 * before ioremap() is functional.
158 * If necessary we round it up to the next 512 pages boundary so
159 * that we can have a single pgd entry and a single pte table:
161 #define NR_FIX_BTMAPS 64
162 #define FIX_BTMAPS_SLOTS 8
163 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
165 (__end_of_permanent_fixed_addresses ^
166 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
168 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
169 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
170 : __end_of_permanent_fixed_addresses,
171 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
175 #ifdef CONFIG_INTEL_TXT
178 __end_of_fixed_addresses
182 extern void reserve_top_address(unsigned long reserve);
184 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
185 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
187 extern int fixmaps_set;
189 extern pte_t *kmap_pte;
190 #define kmap_prot PAGE_KERNEL
191 extern pte_t *pkmap_page_table;
193 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
194 void native_set_fixmap(enum fixed_addresses idx,
195 phys_addr_t phys, pgprot_t flags);
197 #ifndef CONFIG_PARAVIRT
198 static inline void __set_fixmap(enum fixed_addresses idx,
199 phys_addr_t phys, pgprot_t flags)
201 native_set_fixmap(idx, phys, flags);
206 * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
207 * supported for MMIO addresses, so make sure that the memory encryption
208 * mask is not part of the page attributes.
210 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
213 * Early memremap routines used for in-place encryption. The mappings created
214 * by these routines are intended to be used as temporary mappings.
216 void __init *early_memremap_encrypted(resource_size_t phys_addr,
218 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
220 void __init *early_memremap_decrypted(resource_size_t phys_addr,
222 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
225 #include <asm-generic/fixmap.h>
227 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
228 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
230 void __early_set_fixmap(enum fixed_addresses idx,
231 phys_addr_t phys, pgprot_t flags);
233 static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page)
235 BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
237 return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page;
240 #define __get_cpu_entry_area_offset_index(cpu, offset) ({ \
241 BUILD_BUG_ON(offset % PAGE_SIZE != 0); \
242 __get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \
245 #define get_cpu_entry_area_index(cpu, field) \
246 __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field))
248 static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
250 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
253 static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu)
255 return &get_cpu_entry_area(cpu)->SYSENTER_stack_page.stack;
258 #endif /* !__ASSEMBLY__ */
259 #endif /* _ASM_X86_FIXMAP_H */