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 extern unsigned long efi_mixed_mode_stack_pa; 16 17 /* 18 * We map the EFI regions needed for runtime services non-contiguously, 19 * with preserved alignment on virtual addresses starting from -4G down 20 * for a total max space of 64G. This way, we provide for stable runtime 21 * services addresses across kernels so that a kexec'd kernel can still 22 * use them. 23 * 24 * This is the main reason why we're doing stable VA mappings for RT 25 * services. 26 */ 27 28 #define EFI32_LOADER_SIGNATURE "EL32" 29 #define EFI64_LOADER_SIGNATURE "EL64" 30 31 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF 32 33 /* 34 * The EFI services are called through variadic functions in many cases. These 35 * functions are implemented in assembler and support only a fixed number of 36 * arguments. The macros below allows us to check at build time that we don't 37 * try to call them with too many arguments. 38 * 39 * __efi_nargs() will return the number of arguments if it is 7 or less, and 40 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it 41 * impossible to calculate the exact number of arguments beyond some 42 * pre-defined limit. The maximum number of arguments currently supported by 43 * any of the thunks is 7, so this is good enough for now and can be extended 44 * in the obvious way if we ever need more. 45 */ 46 47 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__) 48 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \ 49 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \ 50 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \ 51 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \ 52 __efi_arg_sentinel(1), __efi_arg_sentinel(0)) 53 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \ 54 __take_second_arg(n, \ 55 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; })) 56 #define __efi_arg_sentinel(n) , n 57 58 /* 59 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis 60 * represents more than n arguments. 61 */ 62 63 #define __efi_nargs_check(f, n, ...) \ 64 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n) 65 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n) 66 #define __efi_nargs_check__(f, p, n) ({ \ 67 BUILD_BUG_ON_MSG( \ 68 (p) > (n), \ 69 #f " called with too many arguments (" #p ">" #n ")"); \ 70 }) 71 72 static inline void efi_fpu_begin(void) 73 { 74 /* 75 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires 76 * that FCW and MXCSR (64-bit) must be initialized prior to calling 77 * UEFI code. (Oddly the spec does not require that the FPU stack 78 * be empty.) 79 */ 80 kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR); 81 } 82 83 static inline void efi_fpu_end(void) 84 { 85 kernel_fpu_end(); 86 } 87 88 #ifdef CONFIG_X86_32 89 #define arch_efi_call_virt_setup() \ 90 ({ \ 91 efi_fpu_begin(); \ 92 firmware_restrict_branch_speculation_start(); \ 93 }) 94 95 #define arch_efi_call_virt_teardown() \ 96 ({ \ 97 firmware_restrict_branch_speculation_end(); \ 98 efi_fpu_end(); \ 99 }) 100 101 #define arch_efi_call_virt(p, f, args...) p->f(args) 102 103 #else /* !CONFIG_X86_32 */ 104 105 #define EFI_LOADER_SIGNATURE "EL64" 106 107 extern asmlinkage u64 __efi_call(void *fp, ...); 108 109 #define efi_call(...) ({ \ 110 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 111 __efi_call(__VA_ARGS__); \ 112 }) 113 114 #define arch_efi_call_virt_setup() \ 115 ({ \ 116 efi_sync_low_kernel_mappings(); \ 117 efi_fpu_begin(); \ 118 firmware_restrict_branch_speculation_start(); \ 119 efi_enter_mm(); \ 120 }) 121 122 #define arch_efi_call_virt(p, f, args...) \ 123 efi_call((void *)p->f, args) \ 124 125 #define arch_efi_call_virt_teardown() \ 126 ({ \ 127 efi_leave_mm(); \ 128 firmware_restrict_branch_speculation_end(); \ 129 efi_fpu_end(); \ 130 }) 131 132 #ifdef CONFIG_KASAN 133 /* 134 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 135 * only in kernel binary. Since the EFI stub linked into a separate binary it 136 * doesn't have __memset(). So we should use standard memset from 137 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 138 */ 139 #undef memcpy 140 #undef memset 141 #undef memmove 142 #endif 143 144 #endif /* CONFIG_X86_32 */ 145 146 extern int __init efi_memblock_x86_reserve_range(void); 147 extern void __init efi_print_memmap(void); 148 extern void __init efi_map_region(efi_memory_desc_t *md); 149 extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 150 extern void efi_sync_low_kernel_mappings(void); 151 extern int __init efi_alloc_page_tables(void); 152 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 153 extern void __init efi_runtime_update_mappings(void); 154 extern void __init efi_dump_pagetable(void); 155 extern void __init efi_apply_memmap_quirks(void); 156 extern int __init efi_reuse_config(u64 tables, int nr_tables); 157 extern void efi_delete_dummy_variable(void); 158 extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr); 159 extern void efi_free_boot_services(void); 160 161 void efi_enter_mm(void); 162 void efi_leave_mm(void); 163 164 /* kexec external ABI */ 165 struct efi_setup_data { 166 u64 fw_vendor; 167 u64 __unused; 168 u64 tables; 169 u64 smbios; 170 u64 reserved[8]; 171 }; 172 173 extern u64 efi_setup; 174 175 #ifdef CONFIG_EFI 176 extern efi_status_t __efi64_thunk(u32, ...); 177 178 #define efi64_thunk(...) ({ \ 179 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \ 180 __efi64_thunk(__VA_ARGS__); \ 181 }) 182 183 static inline bool efi_is_mixed(void) 184 { 185 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 186 return false; 187 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 188 } 189 190 static inline bool efi_runtime_supported(void) 191 { 192 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 193 return true; 194 195 return IS_ENABLED(CONFIG_EFI_MIXED); 196 } 197 198 extern void parse_efi_setup(u64 phys_addr, u32 data_len); 199 200 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt); 201 202 extern void efi_thunk_runtime_setup(void); 203 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 204 unsigned long descriptor_size, 205 u32 descriptor_version, 206 efi_memory_desc_t *virtual_map, 207 unsigned long systab_phys); 208 209 /* arch specific definitions used by the stub code */ 210 211 #ifdef CONFIG_EFI_MIXED 212 213 #define ARCH_HAS_EFISTUB_WRAPPERS 214 215 static inline bool efi_is_64bit(void) 216 { 217 extern const bool efi_is64; 218 219 return efi_is64; 220 } 221 222 static inline bool efi_is_native(void) 223 { 224 return efi_is_64bit(); 225 } 226 227 #define efi_mixed_mode_cast(attr) \ 228 __builtin_choose_expr( \ 229 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 230 (unsigned long)(attr), (attr)) 231 232 #define efi_table_attr(inst, attr) \ 233 (efi_is_native() \ 234 ? inst->attr \ 235 : (__typeof__(inst->attr)) \ 236 efi_mixed_mode_cast(inst->mixed_mode.attr)) 237 238 /* 239 * The following macros allow translating arguments if necessary from native to 240 * mixed mode. The use case for this is to initialize the upper 32 bits of 241 * output parameters, and where the 32-bit method requires a 64-bit argument, 242 * which must be split up into two arguments to be thunked properly. 243 * 244 * As examples, the AllocatePool boot service returns the address of the 245 * allocation, but it will not set the high 32 bits of the address. To ensure 246 * that the full 64-bit address is initialized, we zero-init the address before 247 * calling the thunk. 248 * 249 * The FreePages boot service takes a 64-bit physical address even in 32-bit 250 * mode. For the thunk to work correctly, a native 64-bit call of 251 * free_pages(addr, size) 252 * must be translated to 253 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 254 * so that the two 32-bit halves of addr get pushed onto the stack separately. 255 */ 256 257 static inline void *efi64_zero_upper(void *p) 258 { 259 ((u32 *)p)[1] = 0; 260 return p; 261 } 262 263 static inline u32 efi64_convert_status(efi_status_t status) 264 { 265 return (u32)(status | (u64)status >> 32); 266 } 267 268 #define __efi64_argmap_free_pages(addr, size) \ 269 ((addr), 0, (size)) 270 271 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 272 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 273 274 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 275 ((type), (size), efi64_zero_upper(buffer)) 276 277 #define __efi64_argmap_create_event(type, tpl, f, c, event) \ 278 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 279 280 #define __efi64_argmap_set_timer(event, type, time) \ 281 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 282 283 #define __efi64_argmap_wait_for_event(num, event, index) \ 284 ((num), (event), efi64_zero_upper(index)) 285 286 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 287 ((handle), (protocol), efi64_zero_upper(interface)) 288 289 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 290 ((protocol), (reg), efi64_zero_upper(interface)) 291 292 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 293 ((protocol), (path), efi64_zero_upper(handle)) 294 295 #define __efi64_argmap_exit(handle, status, size, data) \ 296 ((handle), efi64_convert_status(status), (size), (data)) 297 298 /* PCI I/O */ 299 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 300 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 301 efi64_zero_upper(dev), efi64_zero_upper(func)) 302 303 /* LoadFile */ 304 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 305 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 306 307 /* Graphics Output Protocol */ 308 #define __efi64_argmap_query_mode(gop, mode, size, info) \ 309 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 310 311 /* 312 * The macros below handle the plumbing for the argument mapping. To add a 313 * mapping for a specific EFI method, simply define a macro 314 * __efi64_argmap_<method name>, following the examples above. 315 */ 316 317 #define __efi64_thunk_map(inst, func, ...) \ 318 efi64_thunk(inst->mixed_mode.func, \ 319 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 320 (__VA_ARGS__))) 321 322 #define __efi64_argmap(mapped, args) \ 323 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 324 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 325 #define __efi64_argmap__1(mapped, args) __efi_eval args 326 327 #define __efi_eat(...) 328 #define __efi_eval(...) __VA_ARGS__ 329 330 /* The three macros below handle dispatching via the thunk if needed */ 331 332 #define efi_call_proto(inst, func, ...) \ 333 (efi_is_native() \ 334 ? inst->func(inst, ##__VA_ARGS__) \ 335 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 336 337 #define efi_bs_call(func, ...) \ 338 (efi_is_native() \ 339 ? efi_system_table->boottime->func(__VA_ARGS__) \ 340 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 341 boottime), \ 342 func, __VA_ARGS__)) 343 344 #define efi_rt_call(func, ...) \ 345 (efi_is_native() \ 346 ? efi_system_table->runtime->func(__VA_ARGS__) \ 347 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 348 runtime), \ 349 func, __VA_ARGS__)) 350 351 #else /* CONFIG_EFI_MIXED */ 352 353 static inline bool efi_is_64bit(void) 354 { 355 return IS_ENABLED(CONFIG_X86_64); 356 } 357 358 #endif /* CONFIG_EFI_MIXED */ 359 360 extern bool efi_reboot_required(void); 361 extern bool efi_is_table_address(unsigned long phys_addr); 362 363 extern void efi_find_mirror(void); 364 extern void efi_reserve_boot_services(void); 365 #else 366 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 367 static inline bool efi_reboot_required(void) 368 { 369 return false; 370 } 371 static inline bool efi_is_table_address(unsigned long phys_addr) 372 { 373 return false; 374 } 375 static inline void efi_find_mirror(void) 376 { 377 } 378 static inline void efi_reserve_boot_services(void) 379 { 380 } 381 #endif /* CONFIG_EFI */ 382 383 #ifdef CONFIG_EFI_FAKE_MEMMAP 384 extern void __init efi_fake_memmap_early(void); 385 #else 386 static inline void efi_fake_memmap_early(void) 387 { 388 } 389 #endif 390 391 #define arch_ima_efi_boot_mode \ 392 ({ extern struct boot_params boot_params; boot_params.secure_boot; }) 393 394 #endif /* _ASM_X86_EFI_H */ 395