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>
13 extern unsigned long efi_fw_vendor, efi_config_table;
16 * We map the EFI regions needed for runtime services non-contiguously,
17 * with preserved alignment on virtual addresses starting from -4G down
18 * for a total max space of 64G. This way, we provide for stable runtime
19 * services addresses across kernels so that a kexec'd kernel can still
22 * This is the main reason why we're doing stable VA mappings for RT
25 * SGI UV1 machines are known to be incompatible with this scheme, so we
26 * provide an opt-out for these machines via a DMI quirk that sets the
29 #define EFI_UV1_MEMMAP EFI_ARCH_1
31 static inline bool efi_have_uv1_memmap(void)
33 return IS_ENABLED(CONFIG_X86_UV) && efi_enabled(EFI_UV1_MEMMAP);
36 #define EFI32_LOADER_SIGNATURE "EL32"
37 #define EFI64_LOADER_SIGNATURE "EL64"
39 #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF
42 * The EFI services are called through variadic functions in many cases. These
43 * functions are implemented in assembler and support only a fixed number of
44 * arguments. The macros below allows us to check at build time that we don't
45 * try to call them with too many arguments.
47 * __efi_nargs() will return the number of arguments if it is 7 or less, and
48 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
49 * impossible to calculate the exact number of arguments beyond some
50 * pre-defined limit. The maximum number of arguments currently supported by
51 * any of the thunks is 7, so this is good enough for now and can be extended
52 * in the obvious way if we ever need more.
55 #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
56 #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__, \
57 __efi_arg_sentinel(7), __efi_arg_sentinel(6), \
58 __efi_arg_sentinel(5), __efi_arg_sentinel(4), \
59 __efi_arg_sentinel(3), __efi_arg_sentinel(2), \
60 __efi_arg_sentinel(1), __efi_arg_sentinel(0))
61 #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, n, ...) \
62 __take_second_arg(n, \
63 ({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 8; }))
64 #define __efi_arg_sentinel(n) , n
67 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
68 * represents more than n arguments.
71 #define __efi_nargs_check(f, n, ...) \
72 __efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
73 #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
74 #define __efi_nargs_check__(f, p, n) ({ \
77 #f " called with too many arguments (" #p ">" #n ")"); \
81 #define arch_efi_call_virt_setup() \
84 firmware_restrict_branch_speculation_start(); \
87 #define arch_efi_call_virt_teardown() \
89 firmware_restrict_branch_speculation_end(); \
94 #define arch_efi_call_virt(p, f, args...) p->f(args)
96 #define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size)
98 #else /* !CONFIG_X86_32 */
100 #define EFI_LOADER_SIGNATURE "EL64"
102 extern asmlinkage u64 __efi_call(void *fp, ...);
104 #define efi_call(...) ({ \
105 __efi_nargs_check(efi_call, 7, __VA_ARGS__); \
106 __efi_call(__VA_ARGS__); \
110 * struct efi_scratch - Scratch space used while switching to/from efi_mm
111 * @phys_stack: stack used during EFI Mixed Mode
112 * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm
116 struct mm_struct *prev_mm;
119 #define arch_efi_call_virt_setup() \
121 efi_sync_low_kernel_mappings(); \
122 kernel_fpu_begin(); \
123 firmware_restrict_branch_speculation_start(); \
125 if (!efi_have_uv1_memmap()) \
126 efi_switch_mm(&efi_mm); \
129 #define arch_efi_call_virt(p, f, args...) \
130 efi_call((void *)p->f, args) \
132 #define arch_efi_call_virt_teardown() \
134 if (!efi_have_uv1_memmap()) \
135 efi_switch_mm(efi_scratch.prev_mm); \
137 firmware_restrict_branch_speculation_end(); \
141 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
142 u32 type, u64 attribute);
146 * CONFIG_KASAN may redefine memset to __memset. __memset function is present
147 * only in kernel binary. Since the EFI stub linked into a separate binary it
148 * doesn't have __memset(). So we should use standard memset from
149 * arch/x86/boot/compressed/string.c. The same applies to memcpy and memmove.
156 #endif /* CONFIG_X86_32 */
158 extern struct efi_scratch efi_scratch;
159 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
160 extern int __init efi_memblock_x86_reserve_range(void);
161 extern void __init efi_print_memmap(void);
162 extern void __init efi_memory_uc(u64 addr, unsigned long size);
163 extern void __init efi_map_region(efi_memory_desc_t *md);
164 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
165 extern void efi_sync_low_kernel_mappings(void);
166 extern int __init efi_alloc_page_tables(void);
167 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
168 extern void __init old_map_region(efi_memory_desc_t *md);
169 extern void __init runtime_code_page_mkexec(void);
170 extern void __init efi_runtime_update_mappings(void);
171 extern void __init efi_dump_pagetable(void);
172 extern void __init efi_apply_memmap_quirks(void);
173 extern int __init efi_reuse_config(u64 tables, int nr_tables);
174 extern void efi_delete_dummy_variable(void);
175 extern void efi_switch_mm(struct mm_struct *mm);
176 extern void efi_recover_from_page_fault(unsigned long phys_addr);
177 extern void efi_free_boot_services(void);
178 extern pgd_t * __init efi_uv1_memmap_phys_prolog(void);
179 extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd);
181 struct efi_setup_data {
188 extern u64 efi_setup;
191 extern efi_status_t __efi64_thunk(u32, ...);
193 #define efi64_thunk(...) ({ \
194 __efi_nargs_check(efi64_thunk, 6, __VA_ARGS__); \
195 __efi64_thunk(__VA_ARGS__); \
198 static inline bool efi_is_mixed(void)
200 if (!IS_ENABLED(CONFIG_EFI_MIXED))
202 return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
205 static inline bool efi_runtime_supported(void)
207 if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
210 return IS_ENABLED(CONFIG_EFI_MIXED);
213 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
215 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
217 extern void efi_thunk_runtime_setup(void);
218 efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
219 unsigned long descriptor_size,
220 u32 descriptor_version,
221 efi_memory_desc_t *virtual_map,
222 unsigned long systab_phys);
224 /* arch specific definitions used by the stub code */
226 __attribute_const__ bool efi_is_64bit(void);
228 static inline bool efi_is_native(void)
230 if (!IS_ENABLED(CONFIG_X86_64))
232 if (!IS_ENABLED(CONFIG_EFI_MIXED))
234 return efi_is_64bit();
237 #define efi_mixed_mode_cast(attr) \
238 __builtin_choose_expr( \
239 __builtin_types_compatible_p(u32, __typeof__(attr)), \
240 (unsigned long)(attr), (attr))
242 #define efi_table_attr(inst, attr) \
245 : (__typeof__(inst->attr)) \
246 efi_mixed_mode_cast(inst->mixed_mode.attr))
249 * The following macros allow translating arguments if necessary from native to
250 * mixed mode. The use case for this is to initialize the upper 32 bits of
251 * output parameters, and where the 32-bit method requires a 64-bit argument,
252 * which must be split up into two arguments to be thunked properly.
254 * As examples, the AllocatePool boot service returns the address of the
255 * allocation, but it will not set the high 32 bits of the address. To ensure
256 * that the full 64-bit address is initialized, we zero-init the address before
259 * The FreePages boot service takes a 64-bit physical address even in 32-bit
260 * mode. For the thunk to work correctly, a native 64-bit call of
261 * free_pages(addr, size)
262 * must be translated to
263 * efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
264 * so that the two 32-bit halves of addr get pushed onto the stack separately.
267 static inline void *efi64_zero_upper(void *p)
273 static inline u32 efi64_convert_status(efi_status_t status)
275 return (u32)(status | (u64)status >> 32);
278 #define __efi64_argmap_free_pages(addr, size) \
281 #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver) \
282 ((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
284 #define __efi64_argmap_allocate_pool(type, size, buffer) \
285 ((type), (size), efi64_zero_upper(buffer))
287 #define __efi64_argmap_handle_protocol(handle, protocol, interface) \
288 ((handle), (protocol), efi64_zero_upper(interface))
290 #define __efi64_argmap_locate_protocol(protocol, reg, interface) \
291 ((protocol), (reg), efi64_zero_upper(interface))
293 #define __efi64_argmap_locate_device_path(protocol, path, handle) \
294 ((protocol), (path), efi64_zero_upper(handle))
296 #define __efi64_argmap_exit(handle, status, size, data) \
297 ((handle), efi64_convert_status(status), (size), (data))
300 #define __efi64_argmap_get_location(protocol, seg, bus, dev, func) \
301 ((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus), \
302 efi64_zero_upper(dev), efi64_zero_upper(func))
305 #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf) \
306 ((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
309 * The macros below handle the plumbing for the argument mapping. To add a
310 * mapping for a specific EFI method, simply define a macro
311 * __efi64_argmap_<method name>, following the examples above.
314 #define __efi64_thunk_map(inst, func, ...) \
315 efi64_thunk(inst->mixed_mode.func, \
316 __efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__), \
319 #define __efi64_argmap(mapped, args) \
320 __PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
321 #define __efi64_argmap__0(mapped, args) __efi_eval mapped
322 #define __efi64_argmap__1(mapped, args) __efi_eval args
324 #define __efi_eat(...)
325 #define __efi_eval(...) __VA_ARGS__
327 /* The three macros below handle dispatching via the thunk if needed */
329 #define efi_call_proto(inst, func, ...) \
331 ? inst->func(inst, ##__VA_ARGS__) \
332 : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
334 #define efi_bs_call(func, ...) \
336 ? efi_system_table()->boottime->func(__VA_ARGS__) \
337 : __efi64_thunk_map(efi_table_attr(efi_system_table(), \
338 boottime), func, __VA_ARGS__))
340 #define efi_rt_call(func, ...) \
342 ? efi_system_table()->runtime->func(__VA_ARGS__) \
343 : __efi64_thunk_map(efi_table_attr(efi_system_table(), \
344 runtime), func, __VA_ARGS__))
346 extern bool efi_reboot_required(void);
347 extern bool efi_is_table_address(unsigned long phys_addr);
349 extern void efi_find_mirror(void);
350 extern void efi_reserve_boot_services(void);
352 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
353 static inline bool efi_reboot_required(void)
357 static inline bool efi_is_table_address(unsigned long phys_addr)
361 static inline void efi_find_mirror(void)
364 static inline void efi_reserve_boot_services(void)
367 #endif /* CONFIG_EFI */
369 #ifdef CONFIG_EFI_FAKE_MEMMAP
370 extern void __init efi_fake_memmap_early(void);
372 static inline void efi_fake_memmap_early(void)
377 #endif /* _ASM_X86_EFI_H */