1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <asm/fpu/api.h>
6 #include <asm/processor-flags.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>
14 extern unsigned long efi_fw_vendor, efi_config_table;
15 extern unsigned long efi_mixed_mode_stack_pa;
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
24 * This is the main reason why we're doing stable VA mappings for RT
28 #define EFI32_LOADER_SIGNATURE "EL32"
29 #define EFI64_LOADER_SIGNATURE "EL64"
31 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
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.
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.
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
59 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
60 * represents more than n arguments.
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) ({ \
69 #f " called with too many arguments (" #p ">" #n ")"); \
73 #define arch_efi_call_virt_setup() \
76 firmware_restrict_branch_speculation_start(); \
79 #define arch_efi_call_virt_teardown() \
81 firmware_restrict_branch_speculation_end(); \
85 #define arch_efi_call_virt(p, f, args...) p->f(args)
87 #else /* !CONFIG_X86_32 */
89 #define EFI_LOADER_SIGNATURE "EL64"
91 extern asmlinkage u64 __efi_call(void *fp, ...);
93 #define efi_call(...) ({ \
94 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \
95 __efi_call(__VA_ARGS__); \
99 * struct efi_scratch - Scratch space used while switching to/from efi_mm
100 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm
103 struct mm_struct *prev_mm;
106 #define arch_efi_call_virt_setup() \
108 efi_sync_low_kernel_mappings(); \
109 kernel_fpu_begin(); \
110 firmware_restrict_branch_speculation_start(); \
111 efi_switch_mm(&efi_mm); \
114 #define arch_efi_call_virt(p, f, args...) \
115 efi_call((void *)p->f, args) \
117 #define arch_efi_call_virt_teardown() \
119 efi_switch_mm(efi_scratch.prev_mm); \
120 firmware_restrict_branch_speculation_end(); \
126 * CONFIG_KASAN may redefine memset to __memset. __memset function is present
127 * only in kernel binary. Since the EFI stub linked into a separate binary it
128 * doesn't have __memset(). So we should use standard memset from
129 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove.
136 #endif /* CONFIG_X86_32 */
138 extern struct efi_scratch efi_scratch;
139 extern int __init efi_memblock_x86_reserve_range(void);
140 extern void __init efi_print_memmap(void);
141 extern void __init efi_map_region(efi_memory_desc_t *md);
142 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
143 extern void efi_sync_low_kernel_mappings(void);
144 extern int __init efi_alloc_page_tables(void);
145 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
146 extern void __init efi_runtime_update_mappings(void);
147 extern void __init efi_dump_pagetable(void);
148 extern void __init efi_apply_memmap_quirks(void);
149 extern int __init efi_reuse_config(u64 tables, int nr_tables);
150 extern void efi_delete_dummy_variable(void);
151 extern void efi_switch_mm(struct mm_struct *mm);
152 extern void efi_recover_from_page_fault(unsigned long phys_addr);
153 extern void efi_free_boot_services(void);
155 /* kexec external ABI */
156 struct efi_setup_data {
164 extern u64 efi_setup;
167 extern efi_status_t __efi64_thunk(u32, ...);
169 #define efi64_thunk(...) ({ \
170 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \
171 __efi64_thunk(__VA_ARGS__); \
174 static inline bool efi_is_mixed(void)
176 if (!IS_ENABLED(CONFIG_EFI_MIXED))
178 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
181 static inline bool efi_runtime_supported(void)
183 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
186 return IS_ENABLED(CONFIG_EFI_MIXED);
189 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
191 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
193 extern void efi_thunk_runtime_setup(void);
194 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
195 unsigned long descriptor_size,
196 u32 descriptor_version,
197 efi_memory_desc_t *virtual_map,
198 unsigned long systab_phys);
200 /* arch specific definitions used by the stub code */
202 #ifdef CONFIG_EFI_MIXED
204 #define ARCH_HAS_EFISTUB_WRAPPERS
206 static inline bool efi_is_64bit(void)
208 extern const bool efi_is64;
213 static inline bool efi_is_native(void)
215 return efi_is_64bit();
218 #define efi_mixed_mode_cast(attr) \
219 __builtin_choose_expr( \
220 __builtin_types_compatible_p(u32, __typeof__(attr)), \
221 (unsigned long)(attr), (attr))
223 #define efi_table_attr(inst, attr) \
226 : (__typeof__(inst->attr)) \
227 efi_mixed_mode_cast(inst->mixed_mode.attr))
230 * The following macros allow translating arguments if necessary from native to
231 * mixed mode. The use case for this is to initialize the upper 32 bits of
232 * output parameters, and where the 32-bit method requires a 64-bit argument,
233 * which must be split up into two arguments to be thunked properly.
235 * As examples, the AllocatePool boot service returns the address of the
236 * allocation, but it will not set the high 32 bits of the address. To ensure
237 * that the full 64-bit address is initialized, we zero-init the address before
240 * The FreePages boot service takes a 64-bit physical address even in 32-bit
241 * mode. For the thunk to work correctly, a native 64-bit call of
242 * free_pages(addr, size)
243 * must be translated to
244 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
245 * so that the two 32-bit halves of addr get pushed onto the stack separately.
248 static inline void *efi64_zero_upper(void *p)
254 static inline u32 efi64_convert_status(efi_status_t status)
256 return (u32)(status | (u64)status >> 32);
259 #define __efi64_argmap_free_pages(addr, size) \
262 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \
263 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
265 #define __efi64_argmap_allocate_pool(type, size, buffer) \
266 ((type), (size), efi64_zero_upper(buffer))
268 #define __efi64_argmap_create_event(type, tpl, f, c, event) \
269 ((type), (tpl), (f), (c), efi64_zero_upper(event))
271 #define __efi64_argmap_set_timer(event, type, time) \
272 ((event), (type), lower_32_bits(time), upper_32_bits(time))
274 #define __efi64_argmap_wait_for_event(num, event, index) \
275 ((num), (event), efi64_zero_upper(index))
277 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \
278 ((handle), (protocol), efi64_zero_upper(interface))
280 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \
281 ((protocol), (reg), efi64_zero_upper(interface))
283 #define __efi64_argmap_locate_device_path(protocol, path, handle) \
284 ((protocol), (path), efi64_zero_upper(handle))
286 #define __efi64_argmap_exit(handle, status, size, data) \
287 ((handle), efi64_convert_status(status), (size), (data))
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))
295 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \
296 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
298 /* Graphics Output Protocol */
299 #define __efi64_argmap_query_mode(gop, mode, size, info) \
300 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
303 * The macros below handle the plumbing for the argument mapping. To add a
304 * mapping for a specific EFI method, simply define a macro
305 * __efi64_argmap_<method name>, following the examples above.
308 #define __efi64_thunk_map(inst, func, ...) \
309 efi64_thunk(inst->mixed_mode.func, \
310 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \
313 #define __efi64_argmap(mapped, args) \
314 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
315 #define __efi64_argmap__0(mapped, args) __efi_eval mapped
316 #define __efi64_argmap__1(mapped, args) __efi_eval args
318 #define __efi_eat(...)
319 #define __efi_eval(...) __VA_ARGS__
321 /* The three macros below handle dispatching via the thunk if needed */
323 #define efi_call_proto(inst, func, ...) \
325 ? inst->func(inst, ##__VA_ARGS__) \
326 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
328 #define efi_bs_call(func, ...) \
330 ? efi_system_table->boottime->func(__VA_ARGS__) \
331 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
335 #define efi_rt_call(func, ...) \
337 ? efi_system_table->runtime->func(__VA_ARGS__) \
338 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
342 #else /* CONFIG_EFI_MIXED */
344 static inline bool efi_is_64bit(void)
346 return IS_ENABLED(CONFIG_X86_64);
349 #endif /* CONFIG_EFI_MIXED */
351 extern bool efi_reboot_required(void);
352 extern bool efi_is_table_address(unsigned long phys_addr);
354 extern void efi_find_mirror(void);
355 extern void efi_reserve_boot_services(void);
357 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
358 static inline bool efi_reboot_required(void)
362 static inline bool efi_is_table_address(unsigned long phys_addr)
366 static inline void efi_find_mirror(void)
369 static inline void efi_reserve_boot_services(void)
372 #endif /* CONFIG_EFI */
374 #ifdef CONFIG_EFI_FAKE_MEMMAP
375 extern void __init efi_fake_memmap_early(void);
377 static inline void efi_fake_memmap_early(void)
382 #define arch_ima_efi_boot_mode \
383 ({ extern struct boot_params boot_params; boot_params.secure_boot; })
385 #endif /* _ASM_X86_EFI_H */