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 cpu_tss and thus serves (on x86_64) as a 60 * a read-only guard page for the SYSENTER stack at the bottom 61 * of the TSS region. 62 */ 63 struct tss_struct tss; 64 65 char entry_trampoline[PAGE_SIZE]; 66 67 #ifdef CONFIG_X86_64 68 /* 69 * Exception stacks used for IST entries. 70 * 71 * In the future, this should have a separate slot for each stack 72 * with guard pages between them. 73 */ 74 char exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]; 75 #endif 76 }; 77 78 #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE) 79 80 extern void setup_cpu_entry_areas(void); 81 82 /* 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. 92 * 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. 97 * 98 * TLB entries of such buffers will not be flushed across 99 * task switches. 100 */ 101 enum fixed_addresses { 102 #ifdef CONFIG_X86_32 103 FIX_HOLE, 104 #else 105 #ifdef CONFIG_X86_VSYSCALL_EMULATION 106 VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT, 107 #endif 108 #endif 109 FIX_DBGP_BASE, 110 FIX_EARLYCON_MEM_BASE, 111 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 112 FIX_OHCI1394_BASE, 113 #endif 114 #ifdef CONFIG_X86_LOCAL_APIC 115 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 116 #endif 117 #ifdef CONFIG_X86_IO_APIC 118 FIX_IO_APIC_BASE_0, 119 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 120 #endif 121 FIX_RO_IDT, /* Virtual mapping for read-only IDT */ 122 #ifdef CONFIG_X86_32 123 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 126 FIX_PCIE_MCFG, 127 #endif 128 #endif 129 #ifdef CONFIG_PARAVIRT 130 FIX_PARAVIRT_BOOTMAP, 131 #endif 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 135 FIX_LNW_VRTC, 136 #endif 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, 140 141 #ifdef CONFIG_ACPI_APEI_GHES 142 /* Used for GHES mapping from assorted contexts */ 143 FIX_APEI_GHES_IRQ, 144 FIX_APEI_GHES_NMI, 145 #endif 146 147 __end_of_permanent_fixed_addresses, 148 149 /* 150 * 512 temporary boot-time mappings, used by early_ioremap(), 151 * before ioremap() is functional. 152 * 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: 155 */ 156 #define NR_FIX_BTMAPS 64 157 #define FIX_BTMAPS_SLOTS 8 158 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 159 FIX_BTMAP_END = 160 (__end_of_permanent_fixed_addresses ^ 161 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 162 -PTRS_PER_PTE 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, 167 #ifdef CONFIG_X86_32 168 FIX_WP_TEST, 169 #endif 170 #ifdef CONFIG_INTEL_TXT 171 FIX_TBOOT_BASE, 172 #endif 173 __end_of_fixed_addresses 174 }; 175 176 177 extern void reserve_top_address(unsigned long reserve); 178 179 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 180 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 181 182 extern int fixmaps_set; 183 184 extern pte_t *kmap_pte; 185 #define kmap_prot PAGE_KERNEL 186 extern pte_t *pkmap_page_table; 187 188 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); 191 192 #ifndef CONFIG_PARAVIRT 193 static inline void __set_fixmap(enum fixed_addresses idx, 194 phys_addr_t phys, pgprot_t flags) 195 { 196 native_set_fixmap(idx, phys, flags); 197 } 198 #endif 199 200 /* 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. 204 */ 205 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE 206 207 /* 208 * Early memremap routines used for in-place encryption. The mappings created 209 * by these routines are intended to be used as temporary mappings. 210 */ 211 void __init *early_memremap_encrypted(resource_size_t phys_addr, 212 unsigned long size); 213 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, 214 unsigned long size); 215 void __init *early_memremap_decrypted(resource_size_t phys_addr, 216 unsigned long size); 217 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, 218 unsigned long size); 219 220 #include <asm-generic/fixmap.h> 221 222 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags) 223 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0)) 224 225 void __early_set_fixmap(enum fixed_addresses idx, 226 phys_addr_t phys, pgprot_t flags); 227 228 static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page) 229 { 230 BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0); 231 232 return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page; 233 } 234 235 #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); \ 238 }) 239 240 #define get_cpu_entry_area_index(cpu, field) \ 241 __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field)) 242 243 static inline struct cpu_entry_area *get_cpu_entry_area(int cpu) 244 { 245 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0)); 246 } 247 248 static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu) 249 { 250 return &get_cpu_entry_area(cpu)->tss.SYSENTER_stack; 251 } 252 253 #endif /* !__ASSEMBLY__ */ 254 #endif /* _ASM_X86_FIXMAP_H */ 255