1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_EFI_H 3 #define _ASM_X86_EFI_H 4 5 #include <asm/fpu/api.h> 6 #include <asm/processor-flags.h> 7 #include <asm/tlb.h> 8 #include <asm/nospec-branch.h> 9 #include <asm/mmu_context.h> 10 #include <linux/build_bug.h> 11 #include <linux/kernel.h> 12 #include <linux/pgtable.h> 13 14 extern unsigned long efi_fw_vendor, efi_config_table; 15 16 /* 17 * We map the EFI regions needed for runtime services non-contiguously, 18 * with preserved alignment on virtual addresses starting from -4G down 19 * for a total max space of 64G. This way, we provide for stable runtime 20 * services addresses across kernels so that a kexec'd kernel can still 21 * use them. 22 * 23 * This is the main reason why we're doing stable VA mappings for RT 24 * services. 25 */ 26 27 #define EFI32_LOADER_SIGNATURE "EL32" 28 #define EFI64_LOADER_SIGNATURE "EL64" 29 30 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF 31 32 /* 33 * The EFI services are called through variadic functions in many cases. These 34 * functions are implemented in assembler and support only a fixed number of 35 * arguments. The macros below allows us to check at build time that we don't 36 * try to call them with too many arguments. 37 * 38 * __efi_nargs() will return the number of arguments if it is 7 or less, and 39 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it 40 * impossible to calculate the exact number of arguments beyond some 41 * pre-defined limit. The maximum number of arguments currently supported by 42 * any of the thunks is 7, so this is good enough for now and can be extended 43 * in the obvious way if we ever need more. 44 */ 45 46 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__) 47 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \ 48 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \ 49 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \ 50 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \ 51 __efi_arg_sentinel(1), __efi_arg_sentinel(0)) 52 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \ 53 __take_second_arg(n, \ 54 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; })) 55 #define __efi_arg_sentinel(n) , n 56 57 /* 58 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis 59 * represents more than n arguments. 60 */ 61 62 #define __efi_nargs_check(f, n, ...) \ 63 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n) 64 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n) 65 #define __efi_nargs_check__(f, p, n) ({ \ 66 BUILD_BUG_ON_MSG( \ 67 (p) > (n), \ 68 #f " called with too many arguments (" #p ">" #n ")"); \ 69 }) 70 71 #ifdef CONFIG_X86_32 72 #define arch_efi_call_virt_setup() \ 73 ({ \ 74 kernel_fpu_begin(); \ 75 firmware_restrict_branch_speculation_start(); \ 76 }) 77 78 #define arch_efi_call_virt_teardown() \ 79 ({ \ 80 firmware_restrict_branch_speculation_end(); \ 81 kernel_fpu_end(); \ 82 }) 83 84 #define arch_efi_call_virt(p, f, args...) p->f(args) 85 86 #else /* !CONFIG_X86_32 */ 87 88 #define EFI_LOADER_SIGNATURE "EL64" 89 90 extern asmlinkage u64 __efi_call(void *fp, ...); 91 92 #define efi_call(...) ({ \ 93 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 94 __efi_call(__VA_ARGS__); \ 95 }) 96 97 /* 98 * struct efi_scratch - Scratch space used while switching to/from efi_mm 99 * @phys_stack: stack used during EFI Mixed Mode 100 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm 101 */ 102 struct efi_scratch { 103 u64 phys_stack; 104 struct mm_struct *prev_mm; 105 } __packed; 106 107 #define arch_efi_call_virt_setup() \ 108 ({ \ 109 efi_sync_low_kernel_mappings(); \ 110 kernel_fpu_begin(); \ 111 firmware_restrict_branch_speculation_start(); \ 112 efi_switch_mm(&efi_mm); \ 113 }) 114 115 #define arch_efi_call_virt(p, f, args...) \ 116 efi_call((void *)p->f, args) \ 117 118 #define arch_efi_call_virt_teardown() \ 119 ({ \ 120 efi_switch_mm(efi_scratch.prev_mm); \ 121 firmware_restrict_branch_speculation_end(); \ 122 kernel_fpu_end(); \ 123 }) 124 125 #ifdef CONFIG_KASAN 126 /* 127 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 128 * only in kernel binary. Since the EFI stub linked into a separate binary it 129 * doesn't have __memset(). So we should use standard memset from 130 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 131 */ 132 #undef memcpy 133 #undef memset 134 #undef memmove 135 #endif 136 137 #endif /* CONFIG_X86_32 */ 138 139 extern struct efi_scratch efi_scratch; 140 extern int __init efi_memblock_x86_reserve_range(void); 141 extern void __init efi_print_memmap(void); 142 extern void __init efi_map_region(efi_memory_desc_t *md); 143 extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 144 extern void efi_sync_low_kernel_mappings(void); 145 extern int __init efi_alloc_page_tables(void); 146 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 147 extern void __init efi_runtime_update_mappings(void); 148 extern void __init efi_dump_pagetable(void); 149 extern void __init efi_apply_memmap_quirks(void); 150 extern int __init efi_reuse_config(u64 tables, int nr_tables); 151 extern void efi_delete_dummy_variable(void); 152 extern void efi_switch_mm(struct mm_struct *mm); 153 extern void efi_recover_from_page_fault(unsigned long phys_addr); 154 extern void efi_free_boot_services(void); 155 156 /* kexec external ABI */ 157 struct efi_setup_data { 158 u64 fw_vendor; 159 u64 __unused; 160 u64 tables; 161 u64 smbios; 162 u64 reserved[8]; 163 }; 164 165 extern u64 efi_setup; 166 167 #ifdef CONFIG_EFI 168 extern efi_status_t __efi64_thunk(u32, ...); 169 170 #define efi64_thunk(...) ({ \ 171 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \ 172 __efi64_thunk(__VA_ARGS__); \ 173 }) 174 175 static inline bool efi_is_mixed(void) 176 { 177 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 178 return false; 179 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 180 } 181 182 static inline bool efi_runtime_supported(void) 183 { 184 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 185 return true; 186 187 return IS_ENABLED(CONFIG_EFI_MIXED); 188 } 189 190 extern void parse_efi_setup(u64 phys_addr, u32 data_len); 191 192 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt); 193 194 extern void efi_thunk_runtime_setup(void); 195 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 196 unsigned long descriptor_size, 197 u32 descriptor_version, 198 efi_memory_desc_t *virtual_map, 199 unsigned long systab_phys); 200 201 /* arch specific definitions used by the stub code */ 202 203 #ifdef CONFIG_EFI_MIXED 204 205 #define ARCH_HAS_EFISTUB_WRAPPERS 206 207 static inline bool efi_is_64bit(void) 208 { 209 extern const bool efi_is64; 210 211 return efi_is64; 212 } 213 214 static inline bool efi_is_native(void) 215 { 216 if (!IS_ENABLED(CONFIG_X86_64)) 217 return true; 218 return efi_is_64bit(); 219 } 220 221 #define efi_mixed_mode_cast(attr) \ 222 __builtin_choose_expr( \ 223 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 224 (unsigned long)(attr), (attr)) 225 226 #define efi_table_attr(inst, attr) \ 227 (efi_is_native() \ 228 ? inst->attr \ 229 : (__typeof__(inst->attr)) \ 230 efi_mixed_mode_cast(inst->mixed_mode.attr)) 231 232 /* 233 * The following macros allow translating arguments if necessary from native to 234 * mixed mode. The use case for this is to initialize the upper 32 bits of 235 * output parameters, and where the 32-bit method requires a 64-bit argument, 236 * which must be split up into two arguments to be thunked properly. 237 * 238 * As examples, the AllocatePool boot service returns the address of the 239 * allocation, but it will not set the high 32 bits of the address. To ensure 240 * that the full 64-bit address is initialized, we zero-init the address before 241 * calling the thunk. 242 * 243 * The FreePages boot service takes a 64-bit physical address even in 32-bit 244 * mode. For the thunk to work correctly, a native 64-bit call of 245 * free_pages(addr, size) 246 * must be translated to 247 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 248 * so that the two 32-bit halves of addr get pushed onto the stack separately. 249 */ 250 251 static inline void *efi64_zero_upper(void *p) 252 { 253 ((u32 *)p)[1] = 0; 254 return p; 255 } 256 257 static inline u32 efi64_convert_status(efi_status_t status) 258 { 259 return (u32)(status | (u64)status >> 32); 260 } 261 262 #define __efi64_argmap_free_pages(addr, size) \ 263 ((addr), 0, (size)) 264 265 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 266 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 267 268 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 269 ((type), (size), efi64_zero_upper(buffer)) 270 271 #define __efi64_argmap_create_event(type, tpl, f, c, event) \ 272 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 273 274 #define __efi64_argmap_set_timer(event, type, time) \ 275 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 276 277 #define __efi64_argmap_wait_for_event(num, event, index) \ 278 ((num), (event), efi64_zero_upper(index)) 279 280 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 281 ((handle), (protocol), efi64_zero_upper(interface)) 282 283 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 284 ((protocol), (reg), efi64_zero_upper(interface)) 285 286 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 287 ((protocol), (path), efi64_zero_upper(handle)) 288 289 #define __efi64_argmap_exit(handle, status, size, data) \ 290 ((handle), efi64_convert_status(status), (size), (data)) 291 292 /* PCI I/O */ 293 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 294 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 295 efi64_zero_upper(dev), efi64_zero_upper(func)) 296 297 /* LoadFile */ 298 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 299 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 300 301 /* Graphics Output Protocol */ 302 #define __efi64_argmap_query_mode(gop, mode, size, info) \ 303 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 304 305 /* 306 * The macros below handle the plumbing for the argument mapping. To add a 307 * mapping for a specific EFI method, simply define a macro 308 * __efi64_argmap_<method name>, following the examples above. 309 */ 310 311 #define __efi64_thunk_map(inst, func, ...) \ 312 efi64_thunk(inst->mixed_mode.func, \ 313 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 314 (__VA_ARGS__))) 315 316 #define __efi64_argmap(mapped, args) \ 317 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 318 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 319 #define __efi64_argmap__1(mapped, args) __efi_eval args 320 321 #define __efi_eat(...) 322 #define __efi_eval(...) __VA_ARGS__ 323 324 /* The three macros below handle dispatching via the thunk if needed */ 325 326 #define efi_call_proto(inst, func, ...) \ 327 (efi_is_native() \ 328 ? inst->func(inst, ##__VA_ARGS__) \ 329 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 330 331 #define efi_bs_call(func, ...) \ 332 (efi_is_native() \ 333 ? efi_system_table->boottime->func(__VA_ARGS__) \ 334 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 335 boottime), \ 336 func, __VA_ARGS__)) 337 338 #define efi_rt_call(func, ...) \ 339 (efi_is_native() \ 340 ? efi_system_table->runtime->func(__VA_ARGS__) \ 341 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 342 runtime), \ 343 func, __VA_ARGS__)) 344 345 #else /* CONFIG_EFI_MIXED */ 346 347 static inline bool efi_is_64bit(void) 348 { 349 return IS_ENABLED(CONFIG_X86_64); 350 } 351 352 #endif /* CONFIG_EFI_MIXED */ 353 354 extern bool efi_reboot_required(void); 355 extern bool efi_is_table_address(unsigned long phys_addr); 356 357 extern void efi_find_mirror(void); 358 extern void efi_reserve_boot_services(void); 359 #else 360 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 361 static inline bool efi_reboot_required(void) 362 { 363 return false; 364 } 365 static inline bool efi_is_table_address(unsigned long phys_addr) 366 { 367 return false; 368 } 369 static inline void efi_find_mirror(void) 370 { 371 } 372 static inline void efi_reserve_boot_services(void) 373 { 374 } 375 #endif /* CONFIG_EFI */ 376 377 #ifdef CONFIG_EFI_FAKE_MEMMAP 378 extern void __init efi_fake_memmap_early(void); 379 #else 380 static inline void efi_fake_memmap_early(void) 381 { 382 } 383 #endif 384 385 #endif /* _ASM_X86_EFI_H */ 386