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 * SGI UV1 machines are known to be incompatible with this scheme, so we 27 * provide an opt-out for these machines via a DMI quirk that sets the 28 * attribute below. 29 */ 30 #define EFI_UV1_MEMMAP EFI_ARCH_1 31 32 static inline bool efi_have_uv1_memmap(void) 33 { 34 return IS_ENABLED(CONFIG_X86_UV) && efi_enabled(EFI_UV1_MEMMAP); 35 } 36 37 #define EFI32_LOADER_SIGNATURE "EL32" 38 #define EFI64_LOADER_SIGNATURE "EL64" 39 40 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF 41 42 /* 43 * The EFI services are called through variadic functions in many cases. These 44 * functions are implemented in assembler and support only a fixed number of 45 * arguments. The macros below allows us to check at build time that we don't 46 * try to call them with too many arguments. 47 * 48 * __efi_nargs() will return the number of arguments if it is 7 or less, and 49 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it 50 * impossible to calculate the exact number of arguments beyond some 51 * pre-defined limit. The maximum number of arguments currently supported by 52 * any of the thunks is 7, so this is good enough for now and can be extended 53 * in the obvious way if we ever need more. 54 */ 55 56 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__) 57 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \ 58 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \ 59 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \ 60 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \ 61 __efi_arg_sentinel(1), __efi_arg_sentinel(0)) 62 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \ 63 __take_second_arg(n, \ 64 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; })) 65 #define __efi_arg_sentinel(n) , n 66 67 /* 68 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis 69 * represents more than n arguments. 70 */ 71 72 #define __efi_nargs_check(f, n, ...) \ 73 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n) 74 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n) 75 #define __efi_nargs_check__(f, p, n) ({ \ 76 BUILD_BUG_ON_MSG( \ 77 (p) > (n), \ 78 #f " called with too many arguments (" #p ">" #n ")"); \ 79 }) 80 81 #ifdef CONFIG_X86_32 82 #define arch_efi_call_virt_setup() \ 83 ({ \ 84 kernel_fpu_begin(); \ 85 firmware_restrict_branch_speculation_start(); \ 86 }) 87 88 #define arch_efi_call_virt_teardown() \ 89 ({ \ 90 firmware_restrict_branch_speculation_end(); \ 91 kernel_fpu_end(); \ 92 }) 93 94 95 #define arch_efi_call_virt(p, f, args...) p->f(args) 96 97 #define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size) 98 99 #else /* !CONFIG_X86_32 */ 100 101 #define EFI_LOADER_SIGNATURE "EL64" 102 103 extern asmlinkage u64 __efi_call(void *fp, ...); 104 105 #define efi_call(...) ({ \ 106 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 107 __efi_call(__VA_ARGS__); \ 108 }) 109 110 /* 111 * struct efi_scratch - Scratch space used while switching to/from efi_mm 112 * @phys_stack: stack used during EFI Mixed Mode 113 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm 114 */ 115 struct efi_scratch { 116 u64 phys_stack; 117 struct mm_struct *prev_mm; 118 } __packed; 119 120 #define arch_efi_call_virt_setup() \ 121 ({ \ 122 efi_sync_low_kernel_mappings(); \ 123 kernel_fpu_begin(); \ 124 firmware_restrict_branch_speculation_start(); \ 125 \ 126 if (!efi_have_uv1_memmap()) \ 127 efi_switch_mm(&efi_mm); \ 128 }) 129 130 #define arch_efi_call_virt(p, f, args...) \ 131 efi_call((void *)p->f, args) \ 132 133 #define arch_efi_call_virt_teardown() \ 134 ({ \ 135 if (!efi_have_uv1_memmap()) \ 136 efi_switch_mm(efi_scratch.prev_mm); \ 137 \ 138 firmware_restrict_branch_speculation_end(); \ 139 kernel_fpu_end(); \ 140 }) 141 142 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, 143 u32 type, u64 attribute); 144 145 #ifdef CONFIG_KASAN 146 /* 147 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 148 * only in kernel binary. Since the EFI stub linked into a separate binary it 149 * doesn't have __memset(). So we should use standard memset from 150 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 151 */ 152 #undef memcpy 153 #undef memset 154 #undef memmove 155 #endif 156 157 #endif /* CONFIG_X86_32 */ 158 159 extern struct efi_scratch efi_scratch; 160 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable); 161 extern int __init efi_memblock_x86_reserve_range(void); 162 extern void __init efi_print_memmap(void); 163 extern void __init efi_memory_uc(u64 addr, unsigned long size); 164 extern void __init efi_map_region(efi_memory_desc_t *md); 165 extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 166 extern void efi_sync_low_kernel_mappings(void); 167 extern int __init efi_alloc_page_tables(void); 168 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 169 extern void __init old_map_region(efi_memory_desc_t *md); 170 extern void __init runtime_code_page_mkexec(void); 171 extern void __init efi_runtime_update_mappings(void); 172 extern void __init efi_dump_pagetable(void); 173 extern void __init efi_apply_memmap_quirks(void); 174 extern int __init efi_reuse_config(u64 tables, int nr_tables); 175 extern void efi_delete_dummy_variable(void); 176 extern void efi_switch_mm(struct mm_struct *mm); 177 extern void efi_recover_from_page_fault(unsigned long phys_addr); 178 extern void efi_free_boot_services(void); 179 extern pgd_t * __init efi_uv1_memmap_phys_prolog(void); 180 extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd); 181 182 /* kexec external ABI */ 183 struct efi_setup_data { 184 u64 fw_vendor; 185 u64 __unused; 186 u64 tables; 187 u64 smbios; 188 u64 reserved[8]; 189 }; 190 191 extern u64 efi_setup; 192 193 #ifdef CONFIG_EFI 194 extern efi_status_t __efi64_thunk(u32, ...); 195 196 #define efi64_thunk(...) ({ \ 197 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \ 198 __efi64_thunk(__VA_ARGS__); \ 199 }) 200 201 static inline bool efi_is_mixed(void) 202 { 203 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 204 return false; 205 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 206 } 207 208 static inline bool efi_runtime_supported(void) 209 { 210 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 211 return true; 212 213 return IS_ENABLED(CONFIG_EFI_MIXED); 214 } 215 216 extern void parse_efi_setup(u64 phys_addr, u32 data_len); 217 218 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt); 219 220 extern void efi_thunk_runtime_setup(void); 221 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 222 unsigned long descriptor_size, 223 u32 descriptor_version, 224 efi_memory_desc_t *virtual_map, 225 unsigned long systab_phys); 226 227 /* arch specific definitions used by the stub code */ 228 229 #ifdef CONFIG_EFI_MIXED 230 231 #define ARCH_HAS_EFISTUB_WRAPPERS 232 233 static inline bool efi_is_64bit(void) 234 { 235 extern const bool efi_is64; 236 237 return efi_is64; 238 } 239 240 static inline bool efi_is_native(void) 241 { 242 if (!IS_ENABLED(CONFIG_X86_64)) 243 return true; 244 return efi_is_64bit(); 245 } 246 247 #define efi_mixed_mode_cast(attr) \ 248 __builtin_choose_expr( \ 249 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 250 (unsigned long)(attr), (attr)) 251 252 #define efi_table_attr(inst, attr) \ 253 (efi_is_native() \ 254 ? inst->attr \ 255 : (__typeof__(inst->attr)) \ 256 efi_mixed_mode_cast(inst->mixed_mode.attr)) 257 258 /* 259 * The following macros allow translating arguments if necessary from native to 260 * mixed mode. The use case for this is to initialize the upper 32 bits of 261 * output parameters, and where the 32-bit method requires a 64-bit argument, 262 * which must be split up into two arguments to be thunked properly. 263 * 264 * As examples, the AllocatePool boot service returns the address of the 265 * allocation, but it will not set the high 32 bits of the address. To ensure 266 * that the full 64-bit address is initialized, we zero-init the address before 267 * calling the thunk. 268 * 269 * The FreePages boot service takes a 64-bit physical address even in 32-bit 270 * mode. For the thunk to work correctly, a native 64-bit call of 271 * free_pages(addr, size) 272 * must be translated to 273 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 274 * so that the two 32-bit halves of addr get pushed onto the stack separately. 275 */ 276 277 static inline void *efi64_zero_upper(void *p) 278 { 279 ((u32 *)p)[1] = 0; 280 return p; 281 } 282 283 static inline u32 efi64_convert_status(efi_status_t status) 284 { 285 return (u32)(status | (u64)status >> 32); 286 } 287 288 #define __efi64_argmap_free_pages(addr, size) \ 289 ((addr), 0, (size)) 290 291 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 292 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 293 294 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 295 ((type), (size), efi64_zero_upper(buffer)) 296 297 #define __efi64_argmap_create_event(type, tpl, f, c, event) \ 298 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 299 300 #define __efi64_argmap_set_timer(event, type, time) \ 301 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 302 303 #define __efi64_argmap_wait_for_event(num, event, index) \ 304 ((num), (event), efi64_zero_upper(index)) 305 306 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 307 ((handle), (protocol), efi64_zero_upper(interface)) 308 309 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 310 ((protocol), (reg), efi64_zero_upper(interface)) 311 312 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 313 ((protocol), (path), efi64_zero_upper(handle)) 314 315 #define __efi64_argmap_exit(handle, status, size, data) \ 316 ((handle), efi64_convert_status(status), (size), (data)) 317 318 /* PCI I/O */ 319 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 320 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 321 efi64_zero_upper(dev), efi64_zero_upper(func)) 322 323 /* LoadFile */ 324 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 325 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 326 327 /* Graphics Output Protocol */ 328 #define __efi64_argmap_query_mode(gop, mode, size, info) \ 329 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 330 331 /* 332 * The macros below handle the plumbing for the argument mapping. To add a 333 * mapping for a specific EFI method, simply define a macro 334 * __efi64_argmap_<method name>, following the examples above. 335 */ 336 337 #define __efi64_thunk_map(inst, func, ...) \ 338 efi64_thunk(inst->mixed_mode.func, \ 339 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 340 (__VA_ARGS__))) 341 342 #define __efi64_argmap(mapped, args) \ 343 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 344 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 345 #define __efi64_argmap__1(mapped, args) __efi_eval args 346 347 #define __efi_eat(...) 348 #define __efi_eval(...) __VA_ARGS__ 349 350 /* The three macros below handle dispatching via the thunk if needed */ 351 352 #define efi_call_proto(inst, func, ...) \ 353 (efi_is_native() \ 354 ? inst->func(inst, ##__VA_ARGS__) \ 355 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 356 357 #define efi_bs_call(func, ...) \ 358 (efi_is_native() \ 359 ? efi_system_table->boottime->func(__VA_ARGS__) \ 360 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 361 boottime), \ 362 func, __VA_ARGS__)) 363 364 #define efi_rt_call(func, ...) \ 365 (efi_is_native() \ 366 ? efi_system_table->runtime->func(__VA_ARGS__) \ 367 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 368 runtime), \ 369 func, __VA_ARGS__)) 370 371 #else /* CONFIG_EFI_MIXED */ 372 373 static inline bool efi_is_64bit(void) 374 { 375 return IS_ENABLED(CONFIG_X86_64); 376 } 377 378 #endif /* CONFIG_EFI_MIXED */ 379 380 extern bool efi_reboot_required(void); 381 extern bool efi_is_table_address(unsigned long phys_addr); 382 383 extern void efi_find_mirror(void); 384 extern void efi_reserve_boot_services(void); 385 #else 386 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 387 static inline bool efi_reboot_required(void) 388 { 389 return false; 390 } 391 static inline bool efi_is_table_address(unsigned long phys_addr) 392 { 393 return false; 394 } 395 static inline void efi_find_mirror(void) 396 { 397 } 398 static inline void efi_reserve_boot_services(void) 399 { 400 } 401 #endif /* CONFIG_EFI */ 402 403 #ifdef CONFIG_EFI_FAKE_MEMMAP 404 extern void __init efi_fake_memmap_early(void); 405 #else 406 static inline void efi_fake_memmap_early(void) 407 { 408 } 409 #endif 410 411 #endif /* _ASM_X86_EFI_H */ 412