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/pgtable.h> 7 #include <asm/processor-flags.h> 8 #include <asm/tlb.h> 9 #include <asm/nospec-branch.h> 10 #include <asm/mmu_context.h> 11 #include <linux/build_bug.h> 12 13 /* 14 * We map the EFI regions needed for runtime services non-contiguously, 15 * with preserved alignment on virtual addresses starting from -4G down 16 * for a total max space of 64G. This way, we provide for stable runtime 17 * services addresses across kernels so that a kexec'd kernel can still 18 * use them. 19 * 20 * This is the main reason why we're doing stable VA mappings for RT 21 * services. 22 * 23 * SGI UV1 machines are known to be incompatible with this scheme, so we 24 * provide an opt-out for these machines via a DMI quirk that sets the 25 * attribute below. 26 */ 27 #define EFI_UV1_MEMMAP EFI_ARCH_1 28 29 static inline bool efi_have_uv1_memmap(void) 30 { 31 return IS_ENABLED(CONFIG_X86_UV) && efi_enabled(EFI_UV1_MEMMAP); 32 } 33 34 #define EFI32_LOADER_SIGNATURE "EL32" 35 #define EFI64_LOADER_SIGNATURE "EL64" 36 37 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF 38 39 /* 40 * The EFI services are called through variadic functions in many cases. These 41 * functions are implemented in assembler and support only a fixed number of 42 * arguments. The macros below allows us to check at build time that we don't 43 * try to call them with too many arguments. 44 * 45 * __efi_nargs() will return the number of arguments if it is 7 or less, and 46 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it 47 * impossible to calculate the exact number of arguments beyond some 48 * pre-defined limit. The maximum number of arguments currently supported by 49 * any of the thunks is 7, so this is good enough for now and can be extended 50 * in the obvious way if we ever need more. 51 */ 52 53 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__) 54 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \ 55 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \ 56 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \ 57 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \ 58 __efi_arg_sentinel(1), __efi_arg_sentinel(0)) 59 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \ 60 __take_second_arg(n, \ 61 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; })) 62 #define __efi_arg_sentinel(n) , n 63 64 /* 65 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis 66 * represents more than n arguments. 67 */ 68 69 #define __efi_nargs_check(f, n, ...) \ 70 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n) 71 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n) 72 #define __efi_nargs_check__(f, p, n) ({ \ 73 BUILD_BUG_ON_MSG( \ 74 (p) > (n), \ 75 #f " called with too many arguments (" #p ">" #n ")"); \ 76 }) 77 78 #ifdef CONFIG_X86_32 79 #define arch_efi_call_virt_setup() \ 80 ({ \ 81 kernel_fpu_begin(); \ 82 firmware_restrict_branch_speculation_start(); \ 83 }) 84 85 #define arch_efi_call_virt_teardown() \ 86 ({ \ 87 firmware_restrict_branch_speculation_end(); \ 88 kernel_fpu_end(); \ 89 }) 90 91 92 #define arch_efi_call_virt(p, f, args...) p->f(args) 93 94 #define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size) 95 96 #else /* !CONFIG_X86_32 */ 97 98 #define EFI_LOADER_SIGNATURE "EL64" 99 100 extern asmlinkage u64 __efi_call(void *fp, ...); 101 102 #define efi_call(...) ({ \ 103 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \ 104 __efi_call(__VA_ARGS__); \ 105 }) 106 107 /* 108 * struct efi_scratch - Scratch space used while switching to/from efi_mm 109 * @phys_stack: stack used during EFI Mixed Mode 110 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm 111 */ 112 struct efi_scratch { 113 u64 phys_stack; 114 struct mm_struct *prev_mm; 115 } __packed; 116 117 #define arch_efi_call_virt_setup() \ 118 ({ \ 119 efi_sync_low_kernel_mappings(); \ 120 kernel_fpu_begin(); \ 121 firmware_restrict_branch_speculation_start(); \ 122 \ 123 if (!efi_have_uv1_memmap()) \ 124 efi_switch_mm(&efi_mm); \ 125 }) 126 127 #define arch_efi_call_virt(p, f, args...) \ 128 efi_call((void *)p->f, args) \ 129 130 #define arch_efi_call_virt_teardown() \ 131 ({ \ 132 if (!efi_have_uv1_memmap()) \ 133 efi_switch_mm(efi_scratch.prev_mm); \ 134 \ 135 firmware_restrict_branch_speculation_end(); \ 136 kernel_fpu_end(); \ 137 }) 138 139 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, 140 u32 type, u64 attribute); 141 142 #ifdef CONFIG_KASAN 143 /* 144 * CONFIG_KASAN may redefine memset to __memset. __memset function is present 145 * only in kernel binary. Since the EFI stub linked into a separate binary it 146 * doesn't have __memset(). So we should use standard memset from 147 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove. 148 */ 149 #undef memcpy 150 #undef memset 151 #undef memmove 152 #endif 153 154 #endif /* CONFIG_X86_32 */ 155 156 extern struct efi_scratch efi_scratch; 157 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable); 158 extern int __init efi_memblock_x86_reserve_range(void); 159 extern void __init efi_print_memmap(void); 160 extern void __init efi_memory_uc(u64 addr, unsigned long size); 161 extern void __init efi_map_region(efi_memory_desc_t *md); 162 extern void __init efi_map_region_fixed(efi_memory_desc_t *md); 163 extern void efi_sync_low_kernel_mappings(void); 164 extern int __init efi_alloc_page_tables(void); 165 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); 166 extern void __init old_map_region(efi_memory_desc_t *md); 167 extern void __init runtime_code_page_mkexec(void); 168 extern void __init efi_runtime_update_mappings(void); 169 extern void __init efi_dump_pagetable(void); 170 extern void __init efi_apply_memmap_quirks(void); 171 extern int __init efi_reuse_config(u64 tables, int nr_tables); 172 extern void efi_delete_dummy_variable(void); 173 extern void efi_switch_mm(struct mm_struct *mm); 174 extern void efi_recover_from_page_fault(unsigned long phys_addr); 175 extern void efi_free_boot_services(void); 176 extern pgd_t * __init efi_uv1_memmap_phys_prolog(void); 177 extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd); 178 179 struct efi_setup_data { 180 u64 fw_vendor; 181 u64 runtime; 182 u64 tables; 183 u64 smbios; 184 u64 reserved[8]; 185 }; 186 187 extern u64 efi_setup; 188 189 #ifdef CONFIG_EFI 190 extern efi_status_t __efi64_thunk(u32, ...); 191 192 #define efi64_thunk(...) ({ \ 193 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \ 194 __efi64_thunk(__VA_ARGS__); \ 195 }) 196 197 static inline bool efi_is_mixed(void) 198 { 199 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 200 return false; 201 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT); 202 } 203 204 static inline bool efi_runtime_supported(void) 205 { 206 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT)) 207 return true; 208 209 return IS_ENABLED(CONFIG_EFI_MIXED); 210 } 211 212 extern void parse_efi_setup(u64 phys_addr, u32 data_len); 213 214 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt); 215 216 extern void efi_thunk_runtime_setup(void); 217 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size, 218 unsigned long descriptor_size, 219 u32 descriptor_version, 220 efi_memory_desc_t *virtual_map); 221 222 /* arch specific definitions used by the stub code */ 223 224 __attribute_const__ bool efi_is_64bit(void); 225 226 static inline bool efi_is_native(void) 227 { 228 if (!IS_ENABLED(CONFIG_X86_64)) 229 return true; 230 if (!IS_ENABLED(CONFIG_EFI_MIXED)) 231 return true; 232 return efi_is_64bit(); 233 } 234 235 #define efi_mixed_mode_cast(attr) \ 236 __builtin_choose_expr( \ 237 __builtin_types_compatible_p(u32, __typeof__(attr)), \ 238 (unsigned long)(attr), (attr)) 239 240 #define efi_table_attr(inst, attr) \ 241 (efi_is_native() \ 242 ? inst->attr \ 243 : (__typeof__(inst->attr)) \ 244 efi_mixed_mode_cast(inst->mixed_mode.attr)) 245 246 /* 247 * The following macros allow translating arguments if necessary from native to 248 * mixed mode. The use case for this is to initialize the upper 32 bits of 249 * output parameters, and where the 32-bit method requires a 64-bit argument, 250 * which must be split up into two arguments to be thunked properly. 251 * 252 * As examples, the AllocatePool boot service returns the address of the 253 * allocation, but it will not set the high 32 bits of the address. To ensure 254 * that the full 64-bit address is initialized, we zero-init the address before 255 * calling the thunk. 256 * 257 * The FreePages boot service takes a 64-bit physical address even in 32-bit 258 * mode. For the thunk to work correctly, a native 64-bit call of 259 * free_pages(addr, size) 260 * must be translated to 261 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size) 262 * so that the two 32-bit halves of addr get pushed onto the stack separately. 263 */ 264 265 static inline void *efi64_zero_upper(void *p) 266 { 267 ((u32 *)p)[1] = 0; 268 return p; 269 } 270 271 #define __efi64_argmap_free_pages(addr, size) \ 272 ((addr), 0, (size)) 273 274 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \ 275 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver)) 276 277 #define __efi64_argmap_allocate_pool(type, size, buffer) \ 278 ((type), (size), efi64_zero_upper(buffer)) 279 280 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \ 281 ((handle), (protocol), efi64_zero_upper(interface)) 282 283 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \ 284 ((protocol), (reg), efi64_zero_upper(interface)) 285 286 #define __efi64_argmap_locate_device_path(protocol, path, handle) \ 287 ((protocol), (path), efi64_zero_upper(handle)) 288 289 /* PCI I/O */ 290 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \ 291 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \ 292 efi64_zero_upper(dev), efi64_zero_upper(func)) 293 294 /* 295 * The macros below handle the plumbing for the argument mapping. To add a 296 * mapping for a specific EFI method, simply define a macro 297 * __efi64_argmap_<method name>, following the examples above. 298 */ 299 300 #define __efi64_thunk_map(inst, func, ...) \ 301 efi64_thunk(inst->mixed_mode.func, \ 302 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \ 303 (__VA_ARGS__))) 304 305 #define __efi64_argmap(mapped, args) \ 306 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args) 307 #define __efi64_argmap__0(mapped, args) __efi_eval mapped 308 #define __efi64_argmap__1(mapped, args) __efi_eval args 309 310 #define __efi_eat(...) 311 #define __efi_eval(...) __VA_ARGS__ 312 313 /* The three macros below handle dispatching via the thunk if needed */ 314 315 #define efi_call_proto(inst, func, ...) \ 316 (efi_is_native() \ 317 ? inst->func(inst, ##__VA_ARGS__) \ 318 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__)) 319 320 #define efi_bs_call(func, ...) \ 321 (efi_is_native() \ 322 ? efi_system_table()->boottime->func(__VA_ARGS__) \ 323 : __efi64_thunk_map(efi_table_attr(efi_system_table(), \ 324 boottime), func, __VA_ARGS__)) 325 326 #define efi_rt_call(func, ...) \ 327 (efi_is_native() \ 328 ? efi_system_table()->runtime->func(__VA_ARGS__) \ 329 : __efi64_thunk_map(efi_table_attr(efi_system_table(), \ 330 runtime), func, __VA_ARGS__)) 331 332 extern bool efi_reboot_required(void); 333 extern bool efi_is_table_address(unsigned long phys_addr); 334 335 extern void efi_find_mirror(void); 336 extern void efi_reserve_boot_services(void); 337 #else 338 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} 339 static inline bool efi_reboot_required(void) 340 { 341 return false; 342 } 343 static inline bool efi_is_table_address(unsigned long phys_addr) 344 { 345 return false; 346 } 347 static inline void efi_find_mirror(void) 348 { 349 } 350 static inline void efi_reserve_boot_services(void) 351 { 352 } 353 #endif /* CONFIG_EFI */ 354 355 #ifdef CONFIG_EFI_FAKE_MEMMAP 356 extern void __init efi_fake_memmap_early(void); 357 #else 358 static inline void efi_fake_memmap_early(void) 359 { 360 } 361 #endif 362 363 #endif /* _ASM_X86_EFI_H */ 364