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