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 efi_thunk_runtime_setup(void); 201 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 202 unsigned long descriptor_size, 203 u32 descriptor_version, 204 efi_memory_desc_t *virtual_map, 205 unsigned long systab_phys); 206 207 /* arch specific definitions used by the stub code */ 208 209 #ifdef CONFIG_EFI_MIXED 210 211 #define ARCH_HAS_EFISTUB_WRAPPERS 212 213 static inline bool efi_is_64bit(void) 214 { 215 extern const bool efi_is64; 216 217 return efi_is64; 218 } 219 220 static inline bool efi_is_native(void) 221 { 222 return efi_is_64bit(); 223 } 224 225 #define efi_mixed_mode_cast(attr) \ 226 __builtin_choose_expr( \ 227 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 228 (unsigned long)(attr), (attr)) 229 230 #define efi_table_attr(inst, attr) \ 231 (efi_is_native() \ 232 ? inst->attr \ 233 : (__typeof__(inst->attr)) \ 234 efi_mixed_mode_cast(inst->mixed_mode.attr)) 235 236 /* 237 * The following macros allow translating arguments if necessary from native to 238 * mixed mode. The use case for this is to initialize the upper 32 bits of 239 * output parameters, and where the 32-bit method requires a 64-bit argument, 240 * which must be split up into two arguments to be thunked properly. 241 * 242 * As examples, the AllocatePool boot service returns the address of the 243 * allocation, but it will not set the high 32 bits of the address. To ensure 244 * that the full 64-bit address is initialized, we zero-init the address before 245 * calling the thunk. 246 * 247 * The FreePages boot service takes a 64-bit physical address even in 32-bit 248 * mode. For the thunk to work correctly, a native 64-bit call of 249 * free_pages(addr, size) 250 * must be translated to 251 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 252 * so that the two 32-bit halves of addr get pushed onto the stack separately. 253 */ 254 255 static inline void *efi64_zero_upper(void *p) 256 { 257 ((u32 *)p)[1] = 0; 258 return p; 259 } 260 261 static inline u32 efi64_convert_status(efi_status_t status) 262 { 263 return (u32)(status | (u64)status >> 32); 264 } 265 266 #define __efi64_argmap_free_pages(addr, size) \ 267 ((addr), 0, (size)) 268 269 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 270 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 271 272 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 273 ((type), (size), efi64_zero_upper(buffer)) 274 275 #define __efi64_argmap_create_event(type, tpl, f, c, event) \ 276 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 277 278 #define __efi64_argmap_set_timer(event, type, time) \ 279 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 280 281 #define __efi64_argmap_wait_for_event(num, event, index) \ 282 ((num), (event), efi64_zero_upper(index)) 283 284 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 285 ((handle), (protocol), efi64_zero_upper(interface)) 286 287 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 288 ((protocol), (reg), efi64_zero_upper(interface)) 289 290 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 291 ((protocol), (path), efi64_zero_upper(handle)) 292 293 #define __efi64_argmap_exit(handle, status, size, data) \ 294 ((handle), efi64_convert_status(status), (size), (data)) 295 296 /* PCI I/O */ 297 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 298 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 299 efi64_zero_upper(dev), efi64_zero_upper(func)) 300 301 /* LoadFile */ 302 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 303 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 304 305 /* Graphics Output Protocol */ 306 #define __efi64_argmap_query_mode(gop, mode, size, info) \ 307 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 308 309 /* 310 * The macros below handle the plumbing for the argument mapping. To add a 311 * mapping for a specific EFI method, simply define a macro 312 * __efi64_argmap_<method name>, following the examples above. 313 */ 314 315 #define __efi64_thunk_map(inst, func, ...) \ 316 efi64_thunk(inst->mixed_mode.func, \ 317 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 318 (__VA_ARGS__))) 319 320 #define __efi64_argmap(mapped, args) \ 321 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 322 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 323 #define __efi64_argmap__1(mapped, args) __efi_eval args 324 325 #define __efi_eat(...) 326 #define __efi_eval(...) __VA_ARGS__ 327 328 /* The three macros below handle dispatching via the thunk if needed */ 329 330 #define efi_call_proto(inst, func, ...) \ 331 (efi_is_native() \ 332 ? inst->func(inst, ##__VA_ARGS__) \ 333 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 334 335 #define efi_bs_call(func, ...) \ 336 (efi_is_native() \ 337 ? efi_system_table->boottime->func(__VA_ARGS__) \ 338 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 339 boottime), \ 340 func, __VA_ARGS__)) 341 342 #define efi_rt_call(func, ...) \ 343 (efi_is_native() \ 344 ? efi_system_table->runtime->func(__VA_ARGS__) \ 345 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 346 runtime), \ 347 func, __VA_ARGS__)) 348 349 #else /* CONFIG_EFI_MIXED */ 350 351 static inline bool efi_is_64bit(void) 352 { 353 return IS_ENABLED(CONFIG_X86_64); 354 } 355 356 #endif /* CONFIG_EFI_MIXED */ 357 358 extern bool efi_reboot_required(void); 359 extern bool efi_is_table_address(unsigned long phys_addr); 360 361 extern void efi_find_mirror(void); 362 extern void efi_reserve_boot_services(void); 363 #else 364 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 365 static inline bool efi_reboot_required(void) 366 { 367 return false; 368 } 369 static inline bool efi_is_table_address(unsigned long phys_addr) 370 { 371 return false; 372 } 373 static inline void efi_find_mirror(void) 374 { 375 } 376 static inline void efi_reserve_boot_services(void) 377 { 378 } 379 #endif /* CONFIG_EFI */ 380 381 #ifdef CONFIG_EFI_FAKE_MEMMAP 382 extern void __init efi_fake_memmap_early(void); 383 #else 384 static inline void efi_fake_memmap_early(void) 385 { 386 } 387 #endif 388 389 #define arch_ima_efi_boot_mode \ 390 ({ extern struct boot_params boot_params; boot_params.secure_boot; }) 391 392 #endif /* _ASM_X86_EFI_H */ 393