1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <asm/fpu/api.h>
6 #include <asm/pgtable.h>
7 #include <asm/processor-flags.h>
9 #include <asm/nospec-branch.h>
10 #include <asm/mmu_context.h>
11 #include <linux/build_bug.h>
12 #include <linux/kernel.h>
14 extern unsigned long efi_fw_vendor, efi_config_table;
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
23 * This is the main reason why we're doing stable VA mappings for RT
26 * SGI UV1 machines are known to be incompatible with this scheme, so we
27 * provide an opt-out for these machines via a DMI quirk that sets the
30 #define EFI_UV1_MEMMAP EFI_ARCH_1
32 static inline bool efi_have_uv1_memmap(void)
34 return IS_ENABLED(CONFIG_X86_UV) && efi_enabled(EFI_UV1_MEMMAP);
37 #define EFI32_LOADER_SIGNATURE "EL32"
38 #define EFI64_LOADER_SIGNATURE "EL64"
40 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
43 * The EFI services are called through variadic functions in many cases. These
44 * functions are implemented in assembler and support only a fixed number of
45 * arguments. The macros below allows us to check at build time that we don't
46 * try to call them with too many arguments.
48 * __efi_nargs() will return the number of arguments if it is 7 or less, and
49 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
50 * impossible to calculate the exact number of arguments beyond some
51 * pre-defined limit. The maximum number of arguments currently supported by
52 * any of the thunks is 7, so this is good enough for now and can be extended
53 * in the obvious way if we ever need more.
56 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
57 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \
58 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \
59 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \
60 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \
61 __efi_arg_sentinel(1), __efi_arg_sentinel(0))
62 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \
63 __take_second_arg(n, \
64 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; }))
65 #define __efi_arg_sentinel(n) , n
68 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
69 * represents more than n arguments.
72 #define __efi_nargs_check(f, n, ...) \
73 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
74 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
75 #define __efi_nargs_check__(f, p, n) ({ \
78 #f " called with too many arguments (" #p ">" #n ")"); \
82 #define arch_efi_call_virt_setup() \
85 firmware_restrict_branch_speculation_start(); \
88 #define arch_efi_call_virt_teardown() \
90 firmware_restrict_branch_speculation_end(); \
95 #define arch_efi_call_virt(p, f, args...) p->f(args)
97 #define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size)
99 #else /* !CONFIG_X86_32 */
101 #define EFI_LOADER_SIGNATURE "EL64"
103 extern asmlinkage u64 __efi_call(void *fp, ...);
105 #define efi_call(...) ({ \
106 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \
107 __efi_call(__VA_ARGS__); \
111 * struct efi_scratch - Scratch space used while switching to/from efi_mm
112 * @phys_stack: stack used during EFI Mixed Mode
113 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm
117 struct mm_struct *prev_mm;
120 #define arch_efi_call_virt_setup() \
122 efi_sync_low_kernel_mappings(); \
123 kernel_fpu_begin(); \
124 firmware_restrict_branch_speculation_start(); \
126 if (!efi_have_uv1_memmap()) \
127 efi_switch_mm(&efi_mm); \
130 #define arch_efi_call_virt(p, f, args...) \
131 efi_call((void *)p->f, args) \
133 #define arch_efi_call_virt_teardown() \
135 if (!efi_have_uv1_memmap()) \
136 efi_switch_mm(efi_scratch.prev_mm); \
138 firmware_restrict_branch_speculation_end(); \
142 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
143 u32 type, u64 attribute);
147 * CONFIG_KASAN may redefine memset to __memset. __memset function is present
148 * only in kernel binary. Since the EFI stub linked into a separate binary it
149 * doesn't have __memset(). So we should use standard memset from
150 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove.
157 #endif /* CONFIG_X86_32 */
159 extern struct efi_scratch efi_scratch;
160 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
161 extern int __init efi_memblock_x86_reserve_range(void);
162 extern void __init efi_print_memmap(void);
163 extern void __init efi_memory_uc(u64 addr, unsigned long size);
164 extern void __init efi_map_region(efi_memory_desc_t *md);
165 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
166 extern void efi_sync_low_kernel_mappings(void);
167 extern int __init efi_alloc_page_tables(void);
168 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
169 extern void __init old_map_region(efi_memory_desc_t *md);
170 extern void __init runtime_code_page_mkexec(void);
171 extern void __init efi_runtime_update_mappings(void);
172 extern void __init efi_dump_pagetable(void);
173 extern void __init efi_apply_memmap_quirks(void);
174 extern int __init efi_reuse_config(u64 tables, int nr_tables);
175 extern void efi_delete_dummy_variable(void);
176 extern void efi_switch_mm(struct mm_struct *mm);
177 extern void efi_recover_from_page_fault(unsigned long phys_addr);
178 extern void efi_free_boot_services(void);
179 extern pgd_t * __init efi_uv1_memmap_phys_prolog(void);
180 extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd);
182 /* kexec external ABI */
183 struct efi_setup_data {
191 extern u64 efi_setup;
194 extern efi_status_t __efi64_thunk(u32, ...);
196 #define efi64_thunk(...) ({ \
197 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \
198 __efi64_thunk(__VA_ARGS__); \
201 static inline bool efi_is_mixed(void)
203 if (!IS_ENABLED(CONFIG_EFI_MIXED))
205 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
208 static inline bool efi_runtime_supported(void)
210 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
213 return IS_ENABLED(CONFIG_EFI_MIXED);
216 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
218 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
220 extern void efi_thunk_runtime_setup(void);
221 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
222 unsigned long descriptor_size,
223 u32 descriptor_version,
224 efi_memory_desc_t *virtual_map,
225 unsigned long systab_phys);
227 /* arch specific definitions used by the stub code */
229 #ifdef CONFIG_EFI_MIXED
231 #define ARCH_HAS_EFISTUB_WRAPPERS
233 static inline bool efi_is_64bit(void)
235 extern const bool efi_is64;
240 static inline bool efi_is_native(void)
242 if (!IS_ENABLED(CONFIG_X86_64))
244 return efi_is_64bit();
247 #define efi_mixed_mode_cast(attr) \
248 __builtin_choose_expr( \
249 __builtin_types_compatible_p(u32, __typeof__(attr)), \
250 (unsigned long)(attr), (attr))
252 #define efi_table_attr(inst, attr) \
255 : (__typeof__(inst->attr)) \
256 efi_mixed_mode_cast(inst->mixed_mode.attr))
259 * The following macros allow translating arguments if necessary from native to
260 * mixed mode. The use case for this is to initialize the upper 32 bits of
261 * output parameters, and where the 32-bit method requires a 64-bit argument,
262 * which must be split up into two arguments to be thunked properly.
264 * As examples, the AllocatePool boot service returns the address of the
265 * allocation, but it will not set the high 32 bits of the address. To ensure
266 * that the full 64-bit address is initialized, we zero-init the address before
269 * The FreePages boot service takes a 64-bit physical address even in 32-bit
270 * mode. For the thunk to work correctly, a native 64-bit call of
271 * free_pages(addr, size)
272 * must be translated to
273 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
274 * so that the two 32-bit halves of addr get pushed onto the stack separately.
277 static inline void *efi64_zero_upper(void *p)
283 static inline u32 efi64_convert_status(efi_status_t status)
285 return (u32)(status | (u64)status >> 32);
288 #define __efi64_argmap_free_pages(addr, size) \
291 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \
292 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
294 #define __efi64_argmap_allocate_pool(type, size, buffer) \
295 ((type), (size), efi64_zero_upper(buffer))
297 #define __efi64_argmap_create_event(type, tpl, f, c, event) \
298 ((type), (tpl), (f), (c), efi64_zero_upper(event))
300 #define __efi64_argmap_set_timer(event, type, time) \
301 ((event), (type), lower_32_bits(time), upper_32_bits(time))
303 #define __efi64_argmap_wait_for_event(num, event, index) \
304 ((num), (event), efi64_zero_upper(index))
306 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \
307 ((handle), (protocol), efi64_zero_upper(interface))
309 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \
310 ((protocol), (reg), efi64_zero_upper(interface))
312 #define __efi64_argmap_locate_device_path(protocol, path, handle) \
313 ((protocol), (path), efi64_zero_upper(handle))
315 #define __efi64_argmap_exit(handle, status, size, data) \
316 ((handle), efi64_convert_status(status), (size), (data))
319 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \
320 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \
321 efi64_zero_upper(dev), efi64_zero_upper(func))
324 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \
325 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
327 /* Graphics Output Protocol */
328 #define __efi64_argmap_query_mode(gop, mode, size, info) \
329 ((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
332 * The macros below handle the plumbing for the argument mapping. To add a
333 * mapping for a specific EFI method, simply define a macro
334 * __efi64_argmap_<method name>, following the examples above.
337 #define __efi64_thunk_map(inst, func, ...) \
338 efi64_thunk(inst->mixed_mode.func, \
339 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \
342 #define __efi64_argmap(mapped, args) \
343 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
344 #define __efi64_argmap__0(mapped, args) __efi_eval mapped
345 #define __efi64_argmap__1(mapped, args) __efi_eval args
347 #define __efi_eat(...)
348 #define __efi_eval(...) __VA_ARGS__
350 /* The three macros below handle dispatching via the thunk if needed */
352 #define efi_call_proto(inst, func, ...) \
354 ? inst->func(inst, ##__VA_ARGS__) \
355 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
357 #define efi_bs_call(func, ...) \
359 ? efi_system_table->boottime->func(__VA_ARGS__) \
360 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
364 #define efi_rt_call(func, ...) \
366 ? efi_system_table->runtime->func(__VA_ARGS__) \
367 : __efi64_thunk_map(efi_table_attr(efi_system_table, \
371 #else /* CONFIG_EFI_MIXED */
373 static inline bool efi_is_64bit(void)
375 return IS_ENABLED(CONFIG_X86_64);
378 #endif /* CONFIG_EFI_MIXED */
380 extern bool efi_reboot_required(void);
381 extern bool efi_is_table_address(unsigned long phys_addr);
383 extern void efi_find_mirror(void);
384 extern void efi_reserve_boot_services(void);
386 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
387 static inline bool efi_reboot_required(void)
391 static inline bool efi_is_table_address(unsigned long phys_addr)
395 static inline void efi_find_mirror(void)
398 static inline void efi_reserve_boot_services(void)
401 #endif /* CONFIG_EFI */
403 #ifdef CONFIG_EFI_FAKE_MEMMAP
404 extern void __init efi_fake_memmap_early(void);
406 static inline void efi_fake_memmap_early(void)
411 #endif /* _ASM_X86_EFI_H */