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 #ifndef __ASSEMBLY__ 18 #include <linux/kernel.h> 19 #include <asm/acpi.h> 20 #include <asm/apicdef.h> 21 #include <asm/page.h> 22 #ifdef CONFIG_X86_32 23 #include <linux/threads.h> 24 #include <asm/kmap_types.h> 25 #else 26 #include <uapi/asm/vsyscall.h> 27 #endif 28 29 /* 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. 33 */ 34 #ifdef CONFIG_X86_32 35 /* used by vmalloc.c, vsyscall.lds.S. 36 * 37 * Leave one empty page between vmalloc'ed areas and 38 * the start of the fixmap. 39 */ 40 extern unsigned long __FIXADDR_TOP; 41 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) 42 #else 43 #define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \ 44 PAGE_SIZE) 45 #endif 46 47 /* 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. 51 * 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. 54 */ 55 struct cpu_entry_area { 56 char gdt[PAGE_SIZE]; 57 58 /* 59 * The GDT is just below SYSENTER_stack and thus serves (on x86_64) as 60 * a a read-only guard page. 61 */ 62 struct SYSENTER_stack_page SYSENTER_stack_page; 63 64 /* 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. 67 */ 68 struct tss_struct tss; 69 70 char entry_trampoline[PAGE_SIZE]; 71 72 #ifdef CONFIG_X86_64 73 /* 74 * Exception stacks used for IST entries. 75 * 76 * In the future, this should have a separate slot for each stack 77 * with guard pages between them. 78 */ 79 char exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]; 80 #endif 81 }; 82 83 #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE) 84 85 extern void setup_cpu_entry_areas(void); 86 87 /* 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. 97 * 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. 102 * 103 * TLB entries of such buffers will not be flushed across 104 * task switches. 105 */ 106 enum fixed_addresses { 107 #ifdef CONFIG_X86_32 108 FIX_HOLE, 109 #else 110 #ifdef CONFIG_X86_VSYSCALL_EMULATION 111 VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT, 112 #endif 113 #endif 114 FIX_DBGP_BASE, 115 FIX_EARLYCON_MEM_BASE, 116 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 117 FIX_OHCI1394_BASE, 118 #endif 119 #ifdef CONFIG_X86_LOCAL_APIC 120 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 121 #endif 122 #ifdef CONFIG_X86_IO_APIC 123 FIX_IO_APIC_BASE_0, 124 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 125 #endif 126 FIX_RO_IDT, /* Virtual mapping for read-only IDT */ 127 #ifdef CONFIG_X86_32 128 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 131 FIX_PCIE_MCFG, 132 #endif 133 #endif 134 #ifdef CONFIG_PARAVIRT 135 FIX_PARAVIRT_BOOTMAP, 136 #endif 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 140 FIX_LNW_VRTC, 141 #endif 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, 145 146 #ifdef CONFIG_ACPI_APEI_GHES 147 /* Used for GHES mapping from assorted contexts */ 148 FIX_APEI_GHES_IRQ, 149 FIX_APEI_GHES_NMI, 150 #endif 151 152 __end_of_permanent_fixed_addresses, 153 154 /* 155 * 512 temporary boot-time mappings, used by early_ioremap(), 156 * before ioremap() is functional. 157 * 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: 160 */ 161 #define NR_FIX_BTMAPS 64 162 #define FIX_BTMAPS_SLOTS 8 163 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 164 FIX_BTMAP_END = 165 (__end_of_permanent_fixed_addresses ^ 166 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 167 -PTRS_PER_PTE 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, 172 #ifdef CONFIG_X86_32 173 FIX_WP_TEST, 174 #endif 175 #ifdef CONFIG_INTEL_TXT 176 FIX_TBOOT_BASE, 177 #endif 178 __end_of_fixed_addresses 179 }; 180 181 182 extern void reserve_top_address(unsigned long reserve); 183 184 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 185 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 186 187 extern int fixmaps_set; 188 189 extern pte_t *kmap_pte; 190 #define kmap_prot PAGE_KERNEL 191 extern pte_t *pkmap_page_table; 192 193 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); 196 197 #ifndef CONFIG_PARAVIRT 198 static inline void __set_fixmap(enum fixed_addresses idx, 199 phys_addr_t phys, pgprot_t flags) 200 { 201 native_set_fixmap(idx, phys, flags); 202 } 203 #endif 204 205 /* 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. 209 */ 210 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE 211 212 /* 213 * Early memremap routines used for in-place encryption. The mappings created 214 * by these routines are intended to be used as temporary mappings. 215 */ 216 void __init *early_memremap_encrypted(resource_size_t phys_addr, 217 unsigned long size); 218 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, 219 unsigned long size); 220 void __init *early_memremap_decrypted(resource_size_t phys_addr, 221 unsigned long size); 222 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, 223 unsigned long size); 224 225 #include <asm-generic/fixmap.h> 226 227 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags) 228 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0)) 229 230 void __early_set_fixmap(enum fixed_addresses idx, 231 phys_addr_t phys, pgprot_t flags); 232 233 static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page) 234 { 235 BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0); 236 237 return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page; 238 } 239 240 #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); \ 243 }) 244 245 #define get_cpu_entry_area_index(cpu, field) \ 246 __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field)) 247 248 static inline struct cpu_entry_area *get_cpu_entry_area(int cpu) 249 { 250 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0)); 251 } 252 253 static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu) 254 { 255 return &get_cpu_entry_area(cpu)->SYSENTER_stack_page.stack; 256 } 257 258 #endif /* !__ASSEMBLY__ */ 259 #endif /* _ASM_X86_FIXMAP_H */ 260