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