xref: /openbmc/linux/arch/x86/include/asm/efi.h (revision e2c75e76)
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/pgtable.h>
7 #include <asm/processor-flags.h>
8 #include <asm/tlb.h>
9 #include <asm/nospec-branch.h>
10 
11 /*
12  * We map the EFI regions needed for runtime services non-contiguously,
13  * with preserved alignment on virtual addresses starting from -4G down
14  * for a total max space of 64G. This way, we provide for stable runtime
15  * services addresses across kernels so that a kexec'd kernel can still
16  * use them.
17  *
18  * This is the main reason why we're doing stable VA mappings for RT
19  * services.
20  *
21  * This flag is used in conjuction with a chicken bit called
22  * "efi=old_map" which can be used as a fallback to the old runtime
23  * services mapping method in case there's some b0rkage with a
24  * particular EFI implementation (haha, it is hard to hold up the
25  * sarcasm here...).
26  */
27 #define EFI_OLD_MEMMAP		EFI_ARCH_1
28 
29 #define EFI32_LOADER_SIGNATURE	"EL32"
30 #define EFI64_LOADER_SIGNATURE	"EL64"
31 
32 #define MAX_CMDLINE_ADDRESS	UINT_MAX
33 
34 #define ARCH_EFI_IRQ_FLAGS_MASK	X86_EFLAGS_IF
35 
36 #ifdef CONFIG_X86_32
37 
38 extern asmlinkage unsigned long efi_call_phys(void *, ...);
39 
40 #define arch_efi_call_virt_setup()					\
41 ({									\
42 	kernel_fpu_begin();						\
43 	firmware_restrict_branch_speculation_start();			\
44 })
45 
46 #define arch_efi_call_virt_teardown()					\
47 ({									\
48 	firmware_restrict_branch_speculation_end();			\
49 	kernel_fpu_end();						\
50 })
51 
52 
53 /*
54  * Wrap all the virtual calls in a way that forces the parameters on the stack.
55  */
56 #define arch_efi_call_virt(p, f, args...)				\
57 ({									\
58 	((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);	\
59 })
60 
61 #define efi_ioremap(addr, size, type, attr)	ioremap_cache(addr, size)
62 
63 #else /* !CONFIG_X86_32 */
64 
65 #define EFI_LOADER_SIGNATURE	"EL64"
66 
67 extern asmlinkage u64 efi_call(void *fp, ...);
68 
69 #define efi_call_phys(f, args...)		efi_call((f), args)
70 
71 /*
72  * Scratch space used for switching the pagetable in the EFI stub
73  */
74 struct efi_scratch {
75 	u64	r15;
76 	u64	prev_cr3;
77 	pgd_t	*efi_pgt;
78 	bool	use_pgd;
79 	u64	phys_stack;
80 } __packed;
81 
82 #define arch_efi_call_virt_setup()					\
83 ({									\
84 	efi_sync_low_kernel_mappings();					\
85 	preempt_disable();						\
86 	__kernel_fpu_begin();						\
87 	firmware_restrict_branch_speculation_start();			\
88 									\
89 	if (efi_scratch.use_pgd) {					\
90 		efi_scratch.prev_cr3 = __read_cr3();			\
91 		write_cr3((unsigned long)efi_scratch.efi_pgt);		\
92 		__flush_tlb_all();					\
93 	}								\
94 })
95 
96 #define arch_efi_call_virt(p, f, args...)				\
97 	efi_call((void *)p->f, args)					\
98 
99 #define arch_efi_call_virt_teardown()					\
100 ({									\
101 	if (efi_scratch.use_pgd) {					\
102 		write_cr3(efi_scratch.prev_cr3);			\
103 		__flush_tlb_all();					\
104 	}								\
105 									\
106 	firmware_restrict_branch_speculation_end();			\
107 	__kernel_fpu_end();						\
108 	preempt_enable();						\
109 })
110 
111 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
112 					u32 type, u64 attribute);
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 struct efi_scratch efi_scratch;
129 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
130 extern int __init efi_memblock_x86_reserve_range(void);
131 extern pgd_t * __init efi_call_phys_prolog(void);
132 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
133 extern void __init efi_print_memmap(void);
134 extern void __init efi_memory_uc(u64 addr, unsigned long size);
135 extern void __init efi_map_region(efi_memory_desc_t *md);
136 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
137 extern void efi_sync_low_kernel_mappings(void);
138 extern int __init efi_alloc_page_tables(void);
139 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
140 extern void __init old_map_region(efi_memory_desc_t *md);
141 extern void __init runtime_code_page_mkexec(void);
142 extern void __init efi_runtime_update_mappings(void);
143 extern void __init efi_dump_pagetable(void);
144 extern void __init efi_apply_memmap_quirks(void);
145 extern int __init efi_reuse_config(u64 tables, int nr_tables);
146 extern void efi_delete_dummy_variable(void);
147 
148 struct efi_setup_data {
149 	u64 fw_vendor;
150 	u64 runtime;
151 	u64 tables;
152 	u64 smbios;
153 	u64 reserved[8];
154 };
155 
156 extern u64 efi_setup;
157 
158 #ifdef CONFIG_EFI
159 
160 static inline bool efi_is_native(void)
161 {
162 	return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
163 }
164 
165 static inline bool efi_runtime_supported(void)
166 {
167 	if (efi_is_native())
168 		return true;
169 
170 	if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
171 		return true;
172 
173 	return false;
174 }
175 
176 extern struct console early_efi_console;
177 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
178 
179 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
180 
181 #ifdef CONFIG_EFI_MIXED
182 extern void efi_thunk_runtime_setup(void);
183 extern efi_status_t efi_thunk_set_virtual_address_map(
184 	void *phys_set_virtual_address_map,
185 	unsigned long memory_map_size,
186 	unsigned long descriptor_size,
187 	u32 descriptor_version,
188 	efi_memory_desc_t *virtual_map);
189 #else
190 static inline void efi_thunk_runtime_setup(void) {}
191 static inline efi_status_t efi_thunk_set_virtual_address_map(
192 	void *phys_set_virtual_address_map,
193 	unsigned long memory_map_size,
194 	unsigned long descriptor_size,
195 	u32 descriptor_version,
196 	efi_memory_desc_t *virtual_map)
197 {
198 	return EFI_SUCCESS;
199 }
200 #endif /* CONFIG_EFI_MIXED */
201 
202 
203 /* arch specific definitions used by the stub code */
204 
205 struct efi_config {
206 	u64 image_handle;
207 	u64 table;
208 	u64 runtime_services;
209 	u64 boot_services;
210 	u64 text_output;
211 	efi_status_t (*call)(unsigned long, ...);
212 	bool is64;
213 } __packed;
214 
215 __pure const struct efi_config *__efi_early(void);
216 
217 static inline bool efi_is_64bit(void)
218 {
219 	if (!IS_ENABLED(CONFIG_X86_64))
220 		return false;
221 
222 	if (!IS_ENABLED(CONFIG_EFI_MIXED))
223 		return true;
224 
225 	return __efi_early()->is64;
226 }
227 
228 #define efi_table_attr(table, attr, instance)				\
229 	(efi_is_64bit() ?						\
230 		((table##_64_t *)(unsigned long)instance)->attr :	\
231 		((table##_32_t *)(unsigned long)instance)->attr)
232 
233 #define efi_call_proto(protocol, f, instance, ...)			\
234 	__efi_early()->call(efi_table_attr(protocol, f, instance),	\
235 		instance, ##__VA_ARGS__)
236 
237 #define efi_call_early(f, ...)						\
238 	__efi_early()->call(efi_table_attr(efi_boot_services, f,	\
239 		__efi_early()->boot_services), __VA_ARGS__)
240 
241 #define __efi_call_early(f, ...)					\
242 	__efi_early()->call((unsigned long)f, __VA_ARGS__);
243 
244 #define efi_call_runtime(f, ...)					\
245 	__efi_early()->call(efi_table_attr(efi_runtime_services, f,	\
246 		__efi_early()->runtime_services), __VA_ARGS__)
247 
248 extern bool efi_reboot_required(void);
249 
250 #else
251 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
252 static inline bool efi_reboot_required(void)
253 {
254 	return false;
255 }
256 #endif /* CONFIG_EFI */
257 
258 #endif /* _ASM_X86_EFI_H */
259