Line data Source code
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 :
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 :
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 :
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 :
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 :
215 : static inline bool efi_is_64bit(void)
216 : {
217 : extern const bool efi_is64;
218 :
219 : return efi_is64;
220 : }
221 :
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 :
257 : static inline void *efi64_zero_upper(void *p)
258 : {
259 : ((u32 *)p)[1] = 0;
260 : return p;
261 : }
262 :
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 :
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
366 : static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
367 : static inline bool efi_reboot_required(void)
368 : {
369 : return false;
370 : }
371 : static inline bool efi_is_table_address(unsigned long phys_addr)
372 : {
373 : return false;
374 : }
375 1 : static inline void efi_find_mirror(void)
376 : {
377 1 : }
378 1 : static inline void efi_reserve_boot_services(void)
379 : {
380 1 : }
381 : #endif /* CONFIG_EFI */
382 :
383 : #ifdef CONFIG_EFI_FAKE_MEMMAP
384 : extern void __init efi_fake_memmap_early(void);
385 : #else
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 */
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