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