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 /*
35 * The EFI services are called through variadic functions in many cases. These
36 * functions are implemented in assembler and support only a fixed number of
37 * arguments. The macros below allows us to check at build time that we don't
38 * try to call them with too many arguments.
39 *
40 * __efi_nargs() will return the number of arguments if it is 7 or less, and
41 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
42 * impossible to calculate the exact number of arguments beyond some
43 * pre-defined limit. The maximum number of arguments currently supported by
44 * any of the thunks is 7, so this is good enough for now and can be extended
45 * in the obvious way if we ever need more.
46 */
47
48 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
49 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \
50 __efi_arg_sentinel(9), __efi_arg_sentinel(8), \
51 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \
52 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \
53 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \
54 __efi_arg_sentinel(1), __efi_arg_sentinel(0))
55 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, ...) \
56 __take_second_arg(n, \
57 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 10; }))
58 #define __efi_arg_sentinel(n) , n
59
60 /*
61 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
62 * represents more than n arguments.
63 */
64
65 #define __efi_nargs_check(f, n, ...) \
66 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
67 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
68 #define __efi_nargs_check__(f, p, n) ({ \
69 BUILD_BUG_ON_MSG( \
70 (p) > (n), \
71 #f " called with too many arguments (" #p ">" #n ")"); \
72 })
73
efi_fpu_begin(void)74 static inline void efi_fpu_begin(void)
75 {
76 /*
77 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires
78 * that FCW and MXCSR (64-bit) must be initialized prior to calling
79 * UEFI code. (Oddly the spec does not require that the FPU stack
80 * be empty.)
81 */
82 kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR);
83 }
84
efi_fpu_end(void)85 static inline void efi_fpu_end(void)
86 {
87 kernel_fpu_end();
88 }
89
90 #ifdef CONFIG_X86_32
91 #define arch_efi_call_virt_setup() \
92 ({ \
93 efi_fpu_begin(); \
94 firmware_restrict_branch_speculation_start(); \
95 })
96
97 #define arch_efi_call_virt_teardown() \
98 ({ \
99 firmware_restrict_branch_speculation_end(); \
100 efi_fpu_end(); \
101 })
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 #undef arch_efi_call_virt
123 #define arch_efi_call_virt(p, f, args...) ({ \
124 u64 ret, ibt = ibt_save(); \
125 ret = efi_call((void *)p->f, args); \
126 ibt_restore(ibt); \
127 ret; \
128 })
129
130 #define arch_efi_call_virt_teardown() \
131 ({ \
132 efi_leave_mm(); \
133 firmware_restrict_branch_speculation_end(); \
134 efi_fpu_end(); \
135 })
136
137 #ifdef CONFIG_KASAN
138 /*
139 * CONFIG_KASAN may redefine memset to __memset. __memset function is present
140 * only in kernel binary. Since the EFI stub linked into a separate binary it
141 * doesn't have __memset(). So we should use standard memset from
142 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove.
143 */
144 #undef memcpy
145 #undef memset
146 #undef memmove
147 #endif
148
149 #endif /* CONFIG_X86_32 */
150
151 extern int __init efi_memblock_x86_reserve_range(void);
152 extern void __init efi_print_memmap(void);
153 extern void __init efi_map_region(efi_memory_desc_t *md);
154 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
155 extern void efi_sync_low_kernel_mappings(void);
156 extern int __init efi_alloc_page_tables(void);
157 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
158 extern void __init efi_runtime_update_mappings(void);
159 extern void __init efi_dump_pagetable(void);
160 extern void __init efi_apply_memmap_quirks(void);
161 extern int __init efi_reuse_config(u64 tables, int nr_tables);
162 extern void efi_delete_dummy_variable(void);
163 extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);
164 extern void efi_free_boot_services(void);
165
166 void efi_enter_mm(void);
167 void efi_leave_mm(void);
168
169 /* kexec external ABI */
170 struct efi_setup_data {
171 u64 fw_vendor;
172 u64 __unused;
173 u64 tables;
174 u64 smbios;
175 u64 reserved[8];
176 };
177
178 extern u64 efi_setup;
179
180 #ifdef CONFIG_EFI
181 extern efi_status_t __efi64_thunk(u32, ...);
182
183 #define efi64_thunk(...) ({ \
184 u64 __pad[3]; /* must have space for 3 args on the stack */ \
185 __efi_nargs_check(efi64_thunk, 9, __VA_ARGS__); \
186 __efi64_thunk(__VA_ARGS__, __pad); \
187 })
188
efi_is_mixed(void)189 static inline bool efi_is_mixed(void)
190 {
191 if (!IS_ENABLED(CONFIG_EFI_MIXED))
192 return false;
193 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
194 }
195
efi_runtime_supported(void)196 static inline bool efi_runtime_supported(void)
197 {
198 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
199 return true;
200
201 return IS_ENABLED(CONFIG_EFI_MIXED);
202 }
203
204 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
205
206 extern void efi_thunk_runtime_setup(void);
207 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
208 unsigned long descriptor_size,
209 u32 descriptor_version,
210 efi_memory_desc_t *virtual_map,
211 unsigned long systab_phys);
212
213 /* arch specific definitions used by the stub code */
214
215 #ifdef CONFIG_EFI_MIXED
216
217 #define ARCH_HAS_EFISTUB_WRAPPERS
218
efi_is_64bit(void)219 static inline bool efi_is_64bit(void)
220 {
221 extern const bool efi_is64;
222
223 return efi_is64;
224 }
225
efi_is_native(void)226 static inline bool efi_is_native(void)
227 {
228 return efi_is_64bit();
229 }
230
231 #define efi_mixed_mode_cast(attr) \
232 __builtin_choose_expr( \
233 __builtin_types_compatible_p(u32, __typeof__(attr)), \
234 (unsigned long)(attr), (attr))
235
236 #define efi_table_attr(inst, attr) \
237 (efi_is_native() \
238 ? inst->attr \
239 : (__typeof__(inst->attr)) \
240 efi_mixed_mode_cast(inst->mixed_mode.attr))
241
242 /*
243 * The following macros allow translating arguments if necessary from native to
244 * mixed mode. The use case for this is to initialize the upper 32 bits of
245 * output parameters, and where the 32-bit method requires a 64-bit argument,
246 * which must be split up into two arguments to be thunked properly.
247 *
248 * As examples, the AllocatePool boot service returns the address of the
249 * allocation, but it will not set the high 32 bits of the address. To ensure
250 * that the full 64-bit address is initialized, we zero-init the address before
251 * calling the thunk.
252 *
253 * The FreePages boot service takes a 64-bit physical address even in 32-bit
254 * mode. For the thunk to work correctly, a native 64-bit call of
255 * free_pages(addr, size)
256 * must be translated to
257 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
258 * so that the two 32-bit halves of addr get pushed onto the stack separately.
259 */
260
efi64_zero_upper(void * p)261 static inline void *efi64_zero_upper(void *p)
262 {
263 ((u32 *)p)[1] = 0;
264 return p;
265 }
266
efi64_convert_status(efi_status_t status)267 static inline u32 efi64_convert_status(efi_status_t status)
268 {
269 return (u32)(status | (u64)status >> 32);
270 }
271
272 #define __efi64_split(val) (val) & U32_MAX, (u64)(val) >> 32
273
274 #define __efi64_argmap_free_pages(addr, size) \
275 ((addr), 0, (size))
276
277 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \
278 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
279
280 #define __efi64_argmap_allocate_pool(type, size, buffer) \
281 ((type), (size), efi64_zero_upper(buffer))
282
283 #define __efi64_argmap_create_event(type, tpl, f, c, event) \
284 ((type), (tpl), (f), (c), efi64_zero_upper(event))
285
286 #define __efi64_argmap_set_timer(event, type, time) \
287 ((event), (type), lower_32_bits(time), upper_32_bits(time))
288
289 #define __efi64_argmap_wait_for_event(num, event, index) \
290 ((num), (event), efi64_zero_upper(index))
291
292 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \
293 ((handle), (protocol), efi64_zero_upper(interface))
294
295 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \
296 ((protocol), (reg), efi64_zero_upper(interface))
297
298 #define __efi64_argmap_locate_device_path(protocol, path, handle) \
299 ((protocol), (path), efi64_zero_upper(handle))
300
301 #define __efi64_argmap_exit(handle, status, size, data) \
302 ((handle), efi64_convert_status(status), (size), (data))
303
304 /* PCI I/O */
305 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \
306 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \
307 efi64_zero_upper(dev), efi64_zero_upper(func))
308
309 /* LoadFile */
310 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \
311 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
312
313 /* Graphics Output Protocol */
314 #define __efi64_argmap_query_mode(gop, mode, size, info) \
315 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
316
317 /* TCG2 protocol */
318 #define __efi64_argmap_hash_log_extend_event(prot, fl, addr, size, ev) \
319 ((prot), (fl), 0ULL, (u64)(addr), 0ULL, (u64)(size), 0ULL, ev)
320
321 /* DXE services */
322 #define __efi64_argmap_get_memory_space_descriptor(phys, desc) \
323 (__efi64_split(phys), (desc))
324
325 #define __efi64_argmap_set_memory_space_attributes(phys, size, flags) \
326 (__efi64_split(phys), __efi64_split(size), __efi64_split(flags))
327
328 /*
329 * The macros below handle the plumbing for the argument mapping. To add a
330 * mapping for a specific EFI method, simply define a macro
331 * __efi64_argmap_<method name>, following the examples above.
332 */
333
334 #define __efi64_thunk_map(inst, func, ...) \
335 efi64_thunk(inst->mixed_mode.func, \
336 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \
337 (__VA_ARGS__)))
338
339 #define __efi64_argmap(mapped, args) \
340 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
341 #define __efi64_argmap__0(mapped, args) __efi_eval mapped
342 #define __efi64_argmap__1(mapped, args) __efi_eval args
343
344 #define __efi_eat(...)
345 #define __efi_eval(...) __VA_ARGS__
346
347 /* The three macros below handle dispatching via the thunk if needed */
348
349 #define efi_call_proto(inst, func, ...) \
350 (efi_is_native() \
351 ? inst->func(inst, ##__VA_ARGS__) \
352 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
353
354 #define efi_bs_call(func, ...) \
355 (efi_is_native() \
356 ? efi_system_table->boottime->func(__VA_ARGS__) \
357 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
358 boottime), \
359 func, __VA_ARGS__))
360
361 #define efi_rt_call(func, ...) \
362 (efi_is_native() \
363 ? efi_system_table->runtime->func(__VA_ARGS__) \
364 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
365 runtime), \
366 func, __VA_ARGS__))
367
368 #define efi_dxe_call(func, ...) \
369 (efi_is_native() \
370 ? efi_dxe_table->func(__VA_ARGS__) \
371 : __efi64_thunk_map(efi_dxe_table, func, __VA_ARGS__))
372
373 #else /* CONFIG_EFI_MIXED */
374
efi_is_64bit(void)375 static inline bool efi_is_64bit(void)
376 {
377 return IS_ENABLED(CONFIG_X86_64);
378 }
379
380 #endif /* CONFIG_EFI_MIXED */
381
382 extern bool efi_reboot_required(void);
383 extern bool efi_is_table_address(unsigned long phys_addr);
384
385 extern void efi_reserve_boot_services(void);
386 #else
parse_efi_setup(u64 phys_addr,u32 data_len)387 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
efi_reboot_required(void)388 static inline bool efi_reboot_required(void)
389 {
390 return false;
391 }
efi_is_table_address(unsigned long phys_addr)392 static inline bool efi_is_table_address(unsigned long phys_addr)
393 {
394 return false;
395 }
efi_reserve_boot_services(void)396 static inline void efi_reserve_boot_services(void)
397 {
398 }
399 #endif /* CONFIG_EFI */
400
401 #ifdef CONFIG_EFI_FAKE_MEMMAP
402 extern void __init efi_fake_memmap_early(void);
403 #else
efi_fake_memmap_early(void)404 static inline void efi_fake_memmap_early(void)
405 {
406 }
407 #endif
408
409 #define arch_ima_efi_boot_mode \
410 ({ extern struct boot_params boot_params; boot_params.secure_boot; })
411
412 #endif /* _ASM_X86_EFI_H */
413