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 85 #define arch_efi_call_virt(p, f, args...) p->f(args) 86 87 #define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size) 88 89 #else /* !CONFIG_X86_32 */ 90 91 #define EFI_LOADER_SIGNATURE "EL64" 92 93 extern asmlinkage u64 __efi_call(void *fp, ...); 94 95 #define efi_call(...) ({ \ 96 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 97 __efi_call(__VA_ARGS__); \ 98 }) 99 100 /* 101 * struct efi_scratch - Scratch space used while switching to/from efi_mm 102 * @phys_stack: stack used during EFI Mixed Mode 103 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm 104 */ 105 struct efi_scratch { 106 u64 phys_stack; 107 struct mm_struct *prev_mm; 108 } __packed; 109 110 #define arch_efi_call_virt_setup() \ 111 ({ \ 112 efi_sync_low_kernel_mappings(); \ 113 kernel_fpu_begin(); \ 114 firmware_restrict_branch_speculation_start(); \ 115 efi_switch_mm(&efi_mm); \ 116 }) 117 118 #define arch_efi_call_virt(p, f, args...) \ 119 efi_call((void *)p->f, args) \ 120 121 #define arch_efi_call_virt_teardown() \ 122 ({ \ 123 efi_switch_mm(efi_scratch.prev_mm); \ 124 firmware_restrict_branch_speculation_end(); \ 125 kernel_fpu_end(); \ 126 }) 127 128 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, 129 u32 type, u64 attribute); 130 131 #ifdef CONFIG_KASAN 132 /* 133 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 134 * only in kernel binary. Since the EFI stub linked into a separate binary it 135 * doesn't have __memset(). So we should use standard memset from 136 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 137 */ 138 #undef memcpy 139 #undef memset 140 #undef memmove 141 #endif 142 143 #endif /* CONFIG_X86_32 */ 144 145 extern struct efi_scratch efi_scratch; 146 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable); 147 extern int __init efi_memblock_x86_reserve_range(void); 148 extern void __init efi_print_memmap(void); 149 extern void __init efi_memory_uc(u64 addr, unsigned long size); 150 extern void __init efi_map_region(efi_memory_desc_t *md); 151 extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 152 extern void efi_sync_low_kernel_mappings(void); 153 extern int __init efi_alloc_page_tables(void); 154 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 155 extern void __init old_map_region(efi_memory_desc_t *md); 156 extern void __init runtime_code_page_mkexec(void); 157 extern void __init efi_runtime_update_mappings(void); 158 extern void __init efi_dump_pagetable(void); 159 extern void __init efi_apply_memmap_quirks(void); 160 extern int __init efi_reuse_config(u64 tables, int nr_tables); 161 extern void efi_delete_dummy_variable(void); 162 extern void efi_switch_mm(struct mm_struct *mm); 163 extern void efi_recover_from_page_fault(unsigned long phys_addr); 164 extern void efi_free_boot_services(void); 165 166 /* kexec external ABI */ 167 struct efi_setup_data { 168 u64 fw_vendor; 169 u64 __unused; 170 u64 tables; 171 u64 smbios; 172 u64 reserved[8]; 173 }; 174 175 extern u64 efi_setup; 176 177 #ifdef CONFIG_EFI 178 extern efi_status_t __efi64_thunk(u32, ...); 179 180 #define efi64_thunk(...) ({ \ 181 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \ 182 __efi64_thunk(__VA_ARGS__); \ 183 }) 184 185 static inline bool efi_is_mixed(void) 186 { 187 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 188 return false; 189 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 190 } 191 192 static inline bool efi_runtime_supported(void) 193 { 194 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 195 return true; 196 197 return IS_ENABLED(CONFIG_EFI_MIXED); 198 } 199 200 extern void parse_efi_setup(u64 phys_addr, u32 data_len); 201 202 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt); 203 204 extern void efi_thunk_runtime_setup(void); 205 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 206 unsigned long descriptor_size, 207 u32 descriptor_version, 208 efi_memory_desc_t *virtual_map, 209 unsigned long systab_phys); 210 211 /* arch specific definitions used by the stub code */ 212 213 #ifdef CONFIG_EFI_MIXED 214 215 #define ARCH_HAS_EFISTUB_WRAPPERS 216 217 static inline bool efi_is_64bit(void) 218 { 219 extern const bool efi_is64; 220 221 return efi_is64; 222 } 223 224 static inline bool efi_is_native(void) 225 { 226 if (!IS_ENABLED(CONFIG_X86_64)) 227 return true; 228 return efi_is_64bit(); 229 } 230 231 #define efi_mixed_mode_cast(attr) \ 232 __builtin_choose_expr( \ 233 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 234 (unsigned long)(attr), (attr)) 235 236 #define efi_table_attr(inst, attr) \ 237 (efi_is_native() \ 238 ? inst->attr \ 239 : (__typeof__(inst->attr)) \ 240 efi_mixed_mode_cast(inst->mixed_mode.attr)) 241 242 /* 243 * The following macros allow translating arguments if necessary from native to 244 * mixed mode. The use case for this is to initialize the upper 32 bits of 245 * output parameters, and where the 32-bit method requires a 64-bit argument, 246 * which must be split up into two arguments to be thunked properly. 247 * 248 * As examples, the AllocatePool boot service returns the address of the 249 * allocation, but it will not set the high 32 bits of the address. To ensure 250 * that the full 64-bit address is initialized, we zero-init the address before 251 * calling the thunk. 252 * 253 * The FreePages boot service takes a 64-bit physical address even in 32-bit 254 * mode. For the thunk to work correctly, a native 64-bit call of 255 * free_pages(addr, size) 256 * must be translated to 257 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 258 * so that the two 32-bit halves of addr get pushed onto the stack separately. 259 */ 260 261 static inline void *efi64_zero_upper(void *p) 262 { 263 ((u32 *)p)[1] = 0; 264 return p; 265 } 266 267 static inline u32 efi64_convert_status(efi_status_t status) 268 { 269 return (u32)(status | (u64)status >> 32); 270 } 271 272 #define __efi64_argmap_free_pages(addr, size) \ 273 ((addr), 0, (size)) 274 275 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 276 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 277 278 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 279 ((type), (size), efi64_zero_upper(buffer)) 280 281 #define __efi64_argmap_create_event(type, tpl, f, c, event) \ 282 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 283 284 #define __efi64_argmap_set_timer(event, type, time) \ 285 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 286 287 #define __efi64_argmap_wait_for_event(num, event, index) \ 288 ((num), (event), efi64_zero_upper(index)) 289 290 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 291 ((handle), (protocol), efi64_zero_upper(interface)) 292 293 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 294 ((protocol), (reg), efi64_zero_upper(interface)) 295 296 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 297 ((protocol), (path), efi64_zero_upper(handle)) 298 299 #define __efi64_argmap_exit(handle, status, size, data) \ 300 ((handle), efi64_convert_status(status), (size), (data)) 301 302 /* PCI I/O */ 303 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 304 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 305 efi64_zero_upper(dev), efi64_zero_upper(func)) 306 307 /* LoadFile */ 308 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 309 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 310 311 /* Graphics Output Protocol */ 312 #define __efi64_argmap_query_mode(gop, mode, size, info) \ 313 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 314 315 /* 316 * The macros below handle the plumbing for the argument mapping. To add a 317 * mapping for a specific EFI method, simply define a macro 318 * __efi64_argmap_<method name>, following the examples above. 319 */ 320 321 #define __efi64_thunk_map(inst, func, ...) \ 322 efi64_thunk(inst->mixed_mode.func, \ 323 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 324 (__VA_ARGS__))) 325 326 #define __efi64_argmap(mapped, args) \ 327 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 328 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 329 #define __efi64_argmap__1(mapped, args) __efi_eval args 330 331 #define __efi_eat(...) 332 #define __efi_eval(...) __VA_ARGS__ 333 334 /* The three macros below handle dispatching via the thunk if needed */ 335 336 #define efi_call_proto(inst, func, ...) \ 337 (efi_is_native() \ 338 ? inst->func(inst, ##__VA_ARGS__) \ 339 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 340 341 #define efi_bs_call(func, ...) \ 342 (efi_is_native() \ 343 ? efi_system_table->boottime->func(__VA_ARGS__) \ 344 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 345 boottime), \ 346 func, __VA_ARGS__)) 347 348 #define efi_rt_call(func, ...) \ 349 (efi_is_native() \ 350 ? efi_system_table->runtime->func(__VA_ARGS__) \ 351 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 352 runtime), \ 353 func, __VA_ARGS__)) 354 355 #else /* CONFIG_EFI_MIXED */ 356 357 static inline bool efi_is_64bit(void) 358 { 359 return IS_ENABLED(CONFIG_X86_64); 360 } 361 362 #endif /* CONFIG_EFI_MIXED */ 363 364 extern bool efi_reboot_required(void); 365 extern bool efi_is_table_address(unsigned long phys_addr); 366 367 extern void efi_find_mirror(void); 368 extern void efi_reserve_boot_services(void); 369 #else 370 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 371 static inline bool efi_reboot_required(void) 372 { 373 return false; 374 } 375 static inline bool efi_is_table_address(unsigned long phys_addr) 376 { 377 return false; 378 } 379 static inline void efi_find_mirror(void) 380 { 381 } 382 static inline void efi_reserve_boot_services(void) 383 { 384 } 385 #endif /* CONFIG_EFI */ 386 387 #ifdef CONFIG_EFI_FAKE_MEMMAP 388 extern void __init efi_fake_memmap_early(void); 389 #else 390 static inline void efi_fake_memmap_early(void) 391 { 392 } 393 #endif 394 395 #endif /* _ASM_X86_EFI_H */ 396