efi.h (12702B)
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 <asm/ibt.h> 11#include <linux/build_bug.h> 12#include <linux/kernel.h> 13#include <linux/pgtable.h> 14 15extern unsigned long efi_fw_vendor, efi_config_table; 16extern unsigned long efi_mixed_mode_stack_pa; 17 18/* 19 * We map the EFI regions needed for runtime services non-contiguously, 20 * with preserved alignment on virtual addresses starting from -4G down 21 * for a total max space of 64G. This way, we provide for stable runtime 22 * services addresses across kernels so that a kexec'd kernel can still 23 * use them. 24 * 25 * This is the main reason why we're doing stable VA mappings for RT 26 * services. 27 */ 28 29#define EFI32_LOADER_SIGNATURE "EL32" 30#define EFI64_LOADER_SIGNATURE "EL64" 31 32#define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF 33 34/* 35 * The EFI services are called through variadic functions in many cases. These 36 * functions are implemented in assembler and support only a fixed number of 37 * arguments. The macros below allows us to check at build time that we don't 38 * try to call them with too many arguments. 39 * 40 * __efi_nargs() will return the number of arguments if it is 7 or less, and 41 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it 42 * impossible to calculate the exact number of arguments beyond some 43 * pre-defined limit. The maximum number of arguments currently supported by 44 * any of the thunks is 7, so this is good enough for now and can be extended 45 * in the obvious way if we ever need more. 46 */ 47 48#define __efi_nargs(...) __efi_nargs_(__VA_ARGS__) 49#define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \ 50 __efi_arg_sentinel(9), __efi_arg_sentinel(8), \ 51 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \ 52 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \ 53 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \ 54 __efi_arg_sentinel(1), __efi_arg_sentinel(0)) 55#define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, ...) \ 56 __take_second_arg(n, \ 57 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 10; })) 58#define __efi_arg_sentinel(n) , n 59 60/* 61 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis 62 * represents more than n arguments. 63 */ 64 65#define __efi_nargs_check(f, n, ...) \ 66 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n) 67#define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n) 68#define __efi_nargs_check__(f, p, n) ({ \ 69 BUILD_BUG_ON_MSG( \ 70 (p) > (n), \ 71 #f " called with too many arguments (" #p ">" #n ")"); \ 72}) 73 74static inline void efi_fpu_begin(void) 75{ 76 /* 77 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires 78 * that FCW and MXCSR (64-bit) must be initialized prior to calling 79 * UEFI code. (Oddly the spec does not require that the FPU stack 80 * be empty.) 81 */ 82 kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR); 83} 84 85static inline void efi_fpu_end(void) 86{ 87 kernel_fpu_end(); 88} 89 90#ifdef CONFIG_X86_32 91#define arch_efi_call_virt_setup() \ 92({ \ 93 efi_fpu_begin(); \ 94 firmware_restrict_branch_speculation_start(); \ 95}) 96 97#define arch_efi_call_virt_teardown() \ 98({ \ 99 firmware_restrict_branch_speculation_end(); \ 100 efi_fpu_end(); \ 101}) 102 103#define arch_efi_call_virt(p, f, args...) p->f(args) 104 105#else /* !CONFIG_X86_32 */ 106 107#define EFI_LOADER_SIGNATURE "EL64" 108 109extern asmlinkage u64 __efi_call(void *fp, ...); 110 111#define efi_call(...) ({ \ 112 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 113 __efi_call(__VA_ARGS__); \ 114}) 115 116#define arch_efi_call_virt_setup() \ 117({ \ 118 efi_sync_low_kernel_mappings(); \ 119 efi_fpu_begin(); \ 120 firmware_restrict_branch_speculation_start(); \ 121 efi_enter_mm(); \ 122}) 123 124#define arch_efi_call_virt(p, f, args...) ({ \ 125 u64 ret, ibt = ibt_save(); \ 126 ret = efi_call((void *)p->f, args); \ 127 ibt_restore(ibt); \ 128 ret; \ 129}) 130 131#define arch_efi_call_virt_teardown() \ 132({ \ 133 efi_leave_mm(); \ 134 firmware_restrict_branch_speculation_end(); \ 135 efi_fpu_end(); \ 136}) 137 138#ifdef CONFIG_KASAN 139/* 140 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 141 * only in kernel binary. Since the EFI stub linked into a separate binary it 142 * doesn't have __memset(). So we should use standard memset from 143 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 144 */ 145#undef memcpy 146#undef memset 147#undef memmove 148#endif 149 150#endif /* CONFIG_X86_32 */ 151 152extern int __init efi_memblock_x86_reserve_range(void); 153extern void __init efi_print_memmap(void); 154extern void __init efi_map_region(efi_memory_desc_t *md); 155extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 156extern void efi_sync_low_kernel_mappings(void); 157extern int __init efi_alloc_page_tables(void); 158extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 159extern void __init efi_runtime_update_mappings(void); 160extern void __init efi_dump_pagetable(void); 161extern void __init efi_apply_memmap_quirks(void); 162extern int __init efi_reuse_config(u64 tables, int nr_tables); 163extern void efi_delete_dummy_variable(void); 164extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr); 165extern void efi_free_boot_services(void); 166 167void efi_enter_mm(void); 168void efi_leave_mm(void); 169 170/* kexec external ABI */ 171struct efi_setup_data { 172 u64 fw_vendor; 173 u64 __unused; 174 u64 tables; 175 u64 smbios; 176 u64 reserved[8]; 177}; 178 179extern u64 efi_setup; 180 181#ifdef CONFIG_EFI 182extern efi_status_t __efi64_thunk(u32, ...); 183 184#define efi64_thunk(...) ({ \ 185 u64 __pad[3]; /* must have space for 3 args on the stack */ \ 186 __efi_nargs_check(efi64_thunk, 9, __VA_ARGS__); \ 187 __efi64_thunk(__VA_ARGS__, __pad); \ 188}) 189 190static inline bool efi_is_mixed(void) 191{ 192 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 193 return false; 194 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 195} 196 197static inline bool efi_runtime_supported(void) 198{ 199 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 200 return true; 201 202 return IS_ENABLED(CONFIG_EFI_MIXED); 203} 204 205extern void parse_efi_setup(u64 phys_addr, u32 data_len); 206 207extern void efi_thunk_runtime_setup(void); 208efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 209 unsigned long descriptor_size, 210 u32 descriptor_version, 211 efi_memory_desc_t *virtual_map, 212 unsigned long systab_phys); 213 214/* arch specific definitions used by the stub code */ 215 216#ifdef CONFIG_EFI_MIXED 217 218#define ARCH_HAS_EFISTUB_WRAPPERS 219 220static inline bool efi_is_64bit(void) 221{ 222 extern const bool efi_is64; 223 224 return efi_is64; 225} 226 227static inline bool efi_is_native(void) 228{ 229 return efi_is_64bit(); 230} 231 232#define efi_mixed_mode_cast(attr) \ 233 __builtin_choose_expr( \ 234 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 235 (unsigned long)(attr), (attr)) 236 237#define efi_table_attr(inst, attr) \ 238 (efi_is_native() \ 239 ? inst->attr \ 240 : (__typeof__(inst->attr)) \ 241 efi_mixed_mode_cast(inst->mixed_mode.attr)) 242 243/* 244 * The following macros allow translating arguments if necessary from native to 245 * mixed mode. The use case for this is to initialize the upper 32 bits of 246 * output parameters, and where the 32-bit method requires a 64-bit argument, 247 * which must be split up into two arguments to be thunked properly. 248 * 249 * As examples, the AllocatePool boot service returns the address of the 250 * allocation, but it will not set the high 32 bits of the address. To ensure 251 * that the full 64-bit address is initialized, we zero-init the address before 252 * calling the thunk. 253 * 254 * The FreePages boot service takes a 64-bit physical address even in 32-bit 255 * mode. For the thunk to work correctly, a native 64-bit call of 256 * free_pages(addr, size) 257 * must be translated to 258 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 259 * so that the two 32-bit halves of addr get pushed onto the stack separately. 260 */ 261 262static inline void *efi64_zero_upper(void *p) 263{ 264 ((u32 *)p)[1] = 0; 265 return p; 266} 267 268static inline u32 efi64_convert_status(efi_status_t status) 269{ 270 return (u32)(status | (u64)status >> 32); 271} 272 273#define __efi64_split(val) (val) & U32_MAX, (u64)(val) >> 32 274 275#define __efi64_argmap_free_pages(addr, size) \ 276 ((addr), 0, (size)) 277 278#define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 279 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 280 281#define __efi64_argmap_allocate_pool(type, size, buffer) \ 282 ((type), (size), efi64_zero_upper(buffer)) 283 284#define __efi64_argmap_create_event(type, tpl, f, c, event) \ 285 ((type), (tpl), (f), (c), efi64_zero_upper(event)) 286 287#define __efi64_argmap_set_timer(event, type, time) \ 288 ((event), (type), lower_32_bits(time), upper_32_bits(time)) 289 290#define __efi64_argmap_wait_for_event(num, event, index) \ 291 ((num), (event), efi64_zero_upper(index)) 292 293#define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 294 ((handle), (protocol), efi64_zero_upper(interface)) 295 296#define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 297 ((protocol), (reg), efi64_zero_upper(interface)) 298 299#define __efi64_argmap_locate_device_path(protocol, path, handle) \ 300 ((protocol), (path), efi64_zero_upper(handle)) 301 302#define __efi64_argmap_exit(handle, status, size, data) \ 303 ((handle), efi64_convert_status(status), (size), (data)) 304 305/* PCI I/O */ 306#define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 307 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 308 efi64_zero_upper(dev), efi64_zero_upper(func)) 309 310/* LoadFile */ 311#define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \ 312 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf)) 313 314/* Graphics Output Protocol */ 315#define __efi64_argmap_query_mode(gop, mode, size, info) \ 316 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info)) 317 318/* TCG2 protocol */ 319#define __efi64_argmap_hash_log_extend_event(prot, fl, addr, size, ev) \ 320 ((prot), (fl), 0ULL, (u64)(addr), 0ULL, (u64)(size), 0ULL, ev) 321 322/* DXE services */ 323#define __efi64_argmap_get_memory_space_descriptor(phys, desc) \ 324 (__efi64_split(phys), (desc)) 325 326#define __efi64_argmap_set_memory_space_attributes(phys, size, flags) \ 327 (__efi64_split(phys), __efi64_split(size), __efi64_split(flags)) 328 329/* 330 * The macros below handle the plumbing for the argument mapping. To add a 331 * mapping for a specific EFI method, simply define a macro 332 * __efi64_argmap_<method name>, following the examples above. 333 */ 334 335#define __efi64_thunk_map(inst, func, ...) \ 336 efi64_thunk(inst->mixed_mode.func, \ 337 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 338 (__VA_ARGS__))) 339 340#define __efi64_argmap(mapped, args) \ 341 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 342#define __efi64_argmap__0(mapped, args) __efi_eval mapped 343#define __efi64_argmap__1(mapped, args) __efi_eval args 344 345#define __efi_eat(...) 346#define __efi_eval(...) __VA_ARGS__ 347 348/* The three macros below handle dispatching via the thunk if needed */ 349 350#define efi_call_proto(inst, func, ...) \ 351 (efi_is_native() \ 352 ? inst->func(inst, ##__VA_ARGS__) \ 353 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 354 355#define efi_bs_call(func, ...) \ 356 (efi_is_native() \ 357 ? efi_system_table->boottime->func(__VA_ARGS__) \ 358 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 359 boottime), \ 360 func, __VA_ARGS__)) 361 362#define efi_rt_call(func, ...) \ 363 (efi_is_native() \ 364 ? efi_system_table->runtime->func(__VA_ARGS__) \ 365 : __efi64_thunk_map(efi_table_attr(efi_system_table, \ 366 runtime), \ 367 func, __VA_ARGS__)) 368 369#define efi_dxe_call(func, ...) \ 370 (efi_is_native() \ 371 ? efi_dxe_table->func(__VA_ARGS__) \ 372 : __efi64_thunk_map(efi_dxe_table, func, __VA_ARGS__)) 373 374#else /* CONFIG_EFI_MIXED */ 375 376static inline bool efi_is_64bit(void) 377{ 378 return IS_ENABLED(CONFIG_X86_64); 379} 380 381#endif /* CONFIG_EFI_MIXED */ 382 383extern bool efi_reboot_required(void); 384extern bool efi_is_table_address(unsigned long phys_addr); 385 386extern void efi_find_mirror(void); 387extern void efi_reserve_boot_services(void); 388#else 389static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 390static inline bool efi_reboot_required(void) 391{ 392 return false; 393} 394static inline bool efi_is_table_address(unsigned long phys_addr) 395{ 396 return false; 397} 398static inline void efi_find_mirror(void) 399{ 400} 401static inline void efi_reserve_boot_services(void) 402{ 403} 404#endif /* CONFIG_EFI */ 405 406#ifdef CONFIG_EFI_FAKE_MEMMAP 407extern void __init efi_fake_memmap_early(void); 408#else 409static inline void efi_fake_memmap_early(void) 410{ 411} 412#endif 413 414#define arch_ima_efi_boot_mode \ 415 ({ extern struct boot_params boot_params; boot_params.secure_boot; }) 416 417#endif /* _ASM_X86_EFI_H */