xref: /linux/arch/x86/include/asm/efi.h (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
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 <asm/ibt.h>
11 #include <linux/build_bug.h>
12 #include <linux/kernel.h>
13 #include <linux/pgtable.h>
14 
15 extern unsigned long efi_fw_vendor, efi_config_table;
16 extern unsigned long efi_mixed_mode_stack_pa;
17 
18 /*
19  * We map the EFI regions needed for runtime services non-contiguously,
20  * with preserved alignment on virtual addresses starting from -4G down
21  * for a total max space of 64G. This way, we provide for stable runtime
22  * services addresses across kernels so that a kexec'd kernel can still
23  * use them.
24  *
25  * This is the main reason why we're doing stable VA mappings for RT
26  * services.
27  */
28 
29 #define EFI32_LOADER_SIGNATURE	"EL32"
30 #define EFI64_LOADER_SIGNATURE	"EL64"
31 
32 #define ARCH_EFI_IRQ_FLAGS_MASK	X86_EFLAGS_IF
33 
34 #define EFI_UNACCEPTED_UNIT_SIZE PMD_SIZE
35 
36 /*
37  * The EFI services are called through variadic functions in many cases. These
38  * functions are implemented in assembler and support only a fixed number of
39  * arguments. The macros below allows us to check at build time that we don't
40  * try to call them with too many arguments.
41  *
42  * __efi_nargs() will return the number of arguments if it is 7 or less, and
43  * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
44  * impossible to calculate the exact number of arguments beyond some
45  * pre-defined limit. The maximum number of arguments currently supported by
46  * any of the thunks is 7, so this is good enough for now and can be extended
47  * in the obvious way if we ever need more.
48  */
49 
50 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
51 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__,	\
52 	__efi_arg_sentinel(9), __efi_arg_sentinel(8),		\
53 	__efi_arg_sentinel(7), __efi_arg_sentinel(6),		\
54 	__efi_arg_sentinel(5), __efi_arg_sentinel(4),		\
55 	__efi_arg_sentinel(3), __efi_arg_sentinel(2),		\
56 	__efi_arg_sentinel(1), __efi_arg_sentinel(0))
57 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, ...)	\
58 	__take_second_arg(n,					\
59 		({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 10; }))
60 #define __efi_arg_sentinel(n) , n
61 
62 /*
63  * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
64  * represents more than n arguments.
65  */
66 
67 #define __efi_nargs_check(f, n, ...)					\
68 	__efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
69 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
70 #define __efi_nargs_check__(f, p, n) ({					\
71 	BUILD_BUG_ON_MSG(						\
72 		(p) > (n),						\
73 		#f " called with too many arguments (" #p ">" #n ")");	\
74 })
75 
76 static inline void efi_fpu_begin(void)
77 {
78 	/*
79 	 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires
80 	 * that FCW and MXCSR (64-bit) must be initialized prior to calling
81 	 * UEFI code.  (Oddly the spec does not require that the FPU stack
82 	 * be empty.)
83 	 */
84 	kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR);
85 }
86 
87 static inline void efi_fpu_end(void)
88 {
89 	kernel_fpu_end();
90 }
91 
92 #ifdef CONFIG_X86_32
93 #define EFI_X86_KERNEL_ALLOC_LIMIT		(SZ_512M - 1)
94 #else /* !CONFIG_X86_32 */
95 #define EFI_X86_KERNEL_ALLOC_LIMIT		EFI_ALLOC_LIMIT
96 
97 extern asmlinkage u64 __efi_call(void *fp, ...);
98 
99 extern bool efi_disable_ibt_for_runtime;
100 
101 #define efi_call(...) ({						\
102 	__efi_nargs_check(efi_call, 7, __VA_ARGS__);			\
103 	__efi_call(__VA_ARGS__);					\
104 })
105 
106 #undef arch_efi_call_virt
107 #define arch_efi_call_virt(p, f, args...) ({				\
108 	u64 ret, ibt = ibt_save(efi_disable_ibt_for_runtime);		\
109 	ret = efi_call((void *)p->f, args);				\
110 	ibt_restore(ibt);						\
111 	ret;								\
112 })
113 
114 #ifdef CONFIG_KASAN
115 /*
116  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
117  * only in kernel binary.  Since the EFI stub linked into a separate binary it
118  * doesn't have __memset().  So we should use standard memset from
119  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
120  */
121 #undef memcpy
122 #undef memset
123 #undef memmove
124 #endif
125 
126 #endif /* CONFIG_X86_32 */
127 
128 extern int __init efi_memblock_x86_reserve_range(void);
129 extern void __init efi_print_memmap(void);
130 extern void __init efi_map_region(efi_memory_desc_t *md);
131 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
132 extern void efi_sync_low_kernel_mappings(void);
133 extern int __init efi_alloc_page_tables(void);
134 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
135 extern void __init efi_runtime_update_mappings(void);
136 extern void __init efi_dump_pagetable(void);
137 extern void __init efi_apply_memmap_quirks(void);
138 extern int __init efi_reuse_config(u64 tables, int nr_tables);
139 extern void efi_delete_dummy_variable(void);
140 extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);
141 extern void efi_free_boot_services(void);
142 
143 void arch_efi_call_virt_setup(void);
144 void arch_efi_call_virt_teardown(void);
145 
146 extern u64 efi_setup;
147 
148 #ifdef CONFIG_EFI
149 extern u64 __efi64_thunk(u32, ...);
150 
151 #define efi64_thunk(...) ({						\
152 	u64 __pad[3]; /* must have space for 3 args on the stack */	\
153 	__efi_nargs_check(efi64_thunk, 9, __VA_ARGS__);			\
154 	__efi64_thunk(__VA_ARGS__, __pad);				\
155 })
156 
157 static inline bool efi_is_mixed(void)
158 {
159 	if (!IS_ENABLED(CONFIG_EFI_MIXED))
160 		return false;
161 	return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
162 }
163 
164 static inline bool efi_runtime_supported(void)
165 {
166 	if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
167 		return true;
168 
169 	return IS_ENABLED(CONFIG_EFI_MIXED);
170 }
171 
172 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
173 
174 extern void efi_thunk_runtime_setup(void);
175 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
176 					 unsigned long descriptor_size,
177 					 u32 descriptor_version,
178 					 efi_memory_desc_t *virtual_map,
179 					 unsigned long systab_phys);
180 
181 /* arch specific definitions used by the stub code */
182 
183 #ifdef CONFIG_EFI_MIXED
184 
185 #define EFI_ALLOC_LIMIT		(efi_is_64bit() ? ULONG_MAX : U32_MAX)
186 
187 #define ARCH_HAS_EFISTUB_WRAPPERS
188 
189 static inline bool efi_is_64bit(void)
190 {
191 	extern const bool efi_is64;
192 
193 	return efi_is64;
194 }
195 
196 static inline bool efi_is_native(void)
197 {
198 	return efi_is_64bit();
199 }
200 
201 #define efi_table_attr(inst, attr)					\
202 	(efi_is_native() ? (inst)->attr					\
203 			 : efi_mixed_table_attr((inst), attr))
204 
205 #define efi_mixed_table_attr(inst, attr)				\
206 	(__typeof__(inst->attr))					\
207 		_Generic(inst->mixed_mode.attr,				\
208 		u32:		(unsigned long)(inst->mixed_mode.attr),	\
209 		default:	(inst->mixed_mode.attr))
210 
211 /*
212  * The following macros allow translating arguments if necessary from native to
213  * mixed mode. The use case for this is to initialize the upper 32 bits of
214  * output parameters, and where the 32-bit method requires a 64-bit argument,
215  * which must be split up into two arguments to be thunked properly.
216  *
217  * As examples, the AllocatePool boot service returns the address of the
218  * allocation, but it will not set the high 32 bits of the address. To ensure
219  * that the full 64-bit address is initialized, we zero-init the address before
220  * calling the thunk.
221  *
222  * The FreePages boot service takes a 64-bit physical address even in 32-bit
223  * mode. For the thunk to work correctly, a native 64-bit call of
224  * 	free_pages(addr, size)
225  * must be translated to
226  * 	efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
227  * so that the two 32-bit halves of addr get pushed onto the stack separately.
228  */
229 
230 static inline void *efi64_zero_upper(void *p)
231 {
232 	((u32 *)p)[1] = 0;
233 	return p;
234 }
235 
236 static inline u32 efi64_convert_status(efi_status_t status)
237 {
238 	return (u32)(status | (u64)status >> 32);
239 }
240 
241 #define __efi64_split(val)		(val) & U32_MAX, (u64)(val) >> 32
242 
243 #define __efi64_argmap_free_pages(addr, size)				\
244 	((addr), 0, (size))
245 
246 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver)	\
247 	((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
248 
249 #define __efi64_argmap_allocate_pool(type, size, buffer)		\
250 	((type), (size), efi64_zero_upper(buffer))
251 
252 #define __efi64_argmap_create_event(type, tpl, f, c, event)		\
253 	((type), (tpl), (f), (c), efi64_zero_upper(event))
254 
255 #define __efi64_argmap_set_timer(event, type, time)			\
256 	((event), (type), lower_32_bits(time), upper_32_bits(time))
257 
258 #define __efi64_argmap_wait_for_event(num, event, index)		\
259 	((num), (event), efi64_zero_upper(index))
260 
261 #define __efi64_argmap_handle_protocol(handle, protocol, interface)	\
262 	((handle), (protocol), efi64_zero_upper(interface))
263 
264 #define __efi64_argmap_locate_protocol(protocol, reg, interface)	\
265 	((protocol), (reg), efi64_zero_upper(interface))
266 
267 #define __efi64_argmap_locate_device_path(protocol, path, handle)	\
268 	((protocol), (path), efi64_zero_upper(handle))
269 
270 #define __efi64_argmap_exit(handle, status, size, data)			\
271 	((handle), efi64_convert_status(status), (size), (data))
272 
273 /* PCI I/O */
274 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func)	\
275 	((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus),	\
276 	 efi64_zero_upper(dev), efi64_zero_upper(func))
277 
278 /* LoadFile */
279 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf)	\
280 	((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
281 
282 /* Graphics Output Protocol */
283 #define __efi64_argmap_query_mode(gop, mode, size, info)		\
284 	((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
285 
286 /* TCG2 protocol */
287 #define __efi64_argmap_hash_log_extend_event(prot, fl, addr, size, ev)	\
288 	((prot), (fl), 0ULL, (u64)(addr), 0ULL, (u64)(size), 0ULL, ev)
289 
290 /* DXE services */
291 #define __efi64_argmap_get_memory_space_descriptor(phys, desc) \
292 	(__efi64_split(phys), (desc))
293 
294 #define __efi64_argmap_set_memory_space_attributes(phys, size, flags) \
295 	(__efi64_split(phys), __efi64_split(size), __efi64_split(flags))
296 
297 /* file protocol */
298 #define __efi64_argmap_open(prot, newh, fname, mode, attr) \
299 	((prot), efi64_zero_upper(newh), (fname), __efi64_split(mode), \
300 	 __efi64_split(attr))
301 
302 #define __efi64_argmap_set_position(pos) (__efi64_split(pos))
303 
304 /* file system protocol */
305 #define __efi64_argmap_open_volume(prot, file) \
306 	((prot), efi64_zero_upper(file))
307 
308 /* Memory Attribute Protocol */
309 #define __efi64_argmap_get_memory_attributes(protocol, phys, size, flags) \
310 	((protocol), __efi64_split(phys), __efi64_split(size), (flags))
311 
312 #define __efi64_argmap_set_memory_attributes(protocol, phys, size, flags) \
313 	((protocol), __efi64_split(phys), __efi64_split(size), __efi64_split(flags))
314 
315 #define __efi64_argmap_clear_memory_attributes(protocol, phys, size, flags) \
316 	((protocol), __efi64_split(phys), __efi64_split(size), __efi64_split(flags))
317 
318 /*
319  * The macros below handle the plumbing for the argument mapping. To add a
320  * mapping for a specific EFI method, simply define a macro
321  * __efi64_argmap_<method name>, following the examples above.
322  */
323 
324 #define __efi64_thunk_map(inst, func, ...)				\
325 	efi64_thunk(inst->mixed_mode.func,				\
326 		__efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__),	\
327 			       (__VA_ARGS__)))
328 
329 #define __efi64_argmap(mapped, args)					\
330 	__PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
331 #define __efi64_argmap__0(mapped, args) __efi_eval mapped
332 #define __efi64_argmap__1(mapped, args) __efi_eval args
333 
334 #define __efi_eat(...)
335 #define __efi_eval(...) __VA_ARGS__
336 
337 static inline efi_status_t __efi64_widen_efi_status(u64 status)
338 {
339 	/* use rotate to move the value of bit #31 into position #63 */
340 	return ror64(rol32(status, 1), 1);
341 }
342 
343 /* The macro below handles dispatching via the thunk if needed */
344 
345 #define efi_fn_call(inst, func, ...)					\
346 	(efi_is_native() ? (inst)->func(__VA_ARGS__)			\
347 			 : efi_mixed_call((inst), func, ##__VA_ARGS__))
348 
349 #define efi_mixed_call(inst, func, ...)					\
350 	_Generic(inst->func(__VA_ARGS__),				\
351 	efi_status_t:							\
352 		__efi64_widen_efi_status(				\
353 			__efi64_thunk_map(inst, func, ##__VA_ARGS__)),	\
354 	u64: ({ BUILD_BUG(); ULONG_MAX; }),				\
355 	default:							\
356 		(__typeof__(inst->func(__VA_ARGS__)))			\
357 			__efi64_thunk_map(inst, func, ##__VA_ARGS__))
358 
359 #else /* CONFIG_EFI_MIXED */
360 
361 static inline bool efi_is_64bit(void)
362 {
363 	return IS_ENABLED(CONFIG_X86_64);
364 }
365 
366 #endif /* CONFIG_EFI_MIXED */
367 
368 extern bool efi_reboot_required(void);
369 extern bool efi_is_table_address(unsigned long phys_addr);
370 
371 extern void efi_reserve_boot_services(void);
372 #else
373 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
374 static inline bool efi_reboot_required(void)
375 {
376 	return false;
377 }
378 static inline  bool efi_is_table_address(unsigned long phys_addr)
379 {
380 	return false;
381 }
382 static inline void efi_reserve_boot_services(void)
383 {
384 }
385 #endif /* CONFIG_EFI */
386 
387 #ifdef CONFIG_EFI_FAKE_MEMMAP
388 extern void __init efi_fake_memmap_early(void);
389 extern void __init efi_fake_memmap(void);
390 #else
391 static inline void efi_fake_memmap_early(void)
392 {
393 }
394 
395 static inline void efi_fake_memmap(void)
396 {
397 }
398 #endif
399 
400 extern int __init efi_memmap_alloc(unsigned int num_entries,
401 				   struct efi_memory_map_data *data);
402 extern void __efi_memmap_free(u64 phys, unsigned long size,
403 			      unsigned long flags);
404 #define __efi_memmap_free __efi_memmap_free
405 
406 extern int __init efi_memmap_install(struct efi_memory_map_data *data);
407 extern int __init efi_memmap_split_count(efi_memory_desc_t *md,
408 					 struct range *range);
409 extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap,
410 				     void *buf, struct efi_mem_range *mem);
411 
412 extern enum efi_secureboot_mode __x86_ima_efi_boot_mode(void);
413 
414 #define arch_ima_efi_boot_mode	__x86_ima_efi_boot_mode()
415 
416 #ifdef CONFIG_EFI_RUNTIME_MAP
417 int efi_get_runtime_map_size(void);
418 int efi_get_runtime_map_desc_size(void);
419 int efi_runtime_map_copy(void *buf, size_t bufsz);
420 #else
421 static inline int efi_get_runtime_map_size(void)
422 {
423 	return 0;
424 }
425 
426 static inline int efi_get_runtime_map_desc_size(void)
427 {
428 	return 0;
429 }
430 
431 static inline int efi_runtime_map_copy(void *buf, size_t bufsz)
432 {
433 	return 0;
434 }
435 
436 #endif
437 
438 #endif /* _ASM_X86_EFI_H */
439