xref: /openbmc/linux/arch/x86/include/asm/efi.h (revision 15d90a6a)
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 #include <asm/mmu_context.h>
11 
12 /*
13  * We map the EFI regions needed for runtime services non-contiguously,
14  * with preserved alignment on virtual addresses starting from -4G down
15  * for a total max space of 64G. This way, we provide for stable runtime
16  * services addresses across kernels so that a kexec'd kernel can still
17  * use them.
18  *
19  * This is the main reason why we're doing stable VA mappings for RT
20  * services.
21  *
22  * This flag is used in conjunction with a chicken bit called
23  * "efi=old_map" which can be used as a fallback to the old runtime
24  * services mapping method in case there's some b0rkage with a
25  * particular EFI implementation (haha, it is hard to hold up the
26  * sarcasm here...).
27  */
28 #define EFI_OLD_MEMMAP		EFI_ARCH_1
29 
30 #define EFI32_LOADER_SIGNATURE	"EL32"
31 #define EFI64_LOADER_SIGNATURE	"EL64"
32 
33 #define MAX_CMDLINE_ADDRESS	UINT_MAX
34 
35 #define ARCH_EFI_IRQ_FLAGS_MASK	X86_EFLAGS_IF
36 
37 #ifdef CONFIG_X86_32
38 
39 extern asmlinkage unsigned long efi_call_phys(void *, ...);
40 
41 #define arch_efi_call_virt_setup()					\
42 ({									\
43 	kernel_fpu_begin();						\
44 	firmware_restrict_branch_speculation_start();			\
45 })
46 
47 #define arch_efi_call_virt_teardown()					\
48 ({									\
49 	firmware_restrict_branch_speculation_end();			\
50 	kernel_fpu_end();						\
51 })
52 
53 
54 /*
55  * Wrap all the virtual calls in a way that forces the parameters on the stack.
56  */
57 #define arch_efi_call_virt(p, f, args...)				\
58 ({									\
59 	((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args);	\
60 })
61 
62 #define efi_ioremap(addr, size, type, attr)	ioremap_cache(addr, size)
63 
64 #else /* !CONFIG_X86_32 */
65 
66 #define EFI_LOADER_SIGNATURE	"EL64"
67 
68 extern asmlinkage u64 efi_call(void *fp, ...);
69 
70 #define efi_call_phys(f, args...)		efi_call((f), args)
71 
72 /*
73  * struct efi_scratch - Scratch space used while switching to/from efi_mm
74  * @phys_stack: stack used during EFI Mixed Mode
75  * @prev_mm:    store/restore stolen mm_struct while switching to/from efi_mm
76  */
77 struct efi_scratch {
78 	u64			phys_stack;
79 	struct mm_struct	*prev_mm;
80 } __packed;
81 
82 #define arch_efi_call_virt_setup()					\
83 ({									\
84 	efi_sync_low_kernel_mappings();					\
85 	kernel_fpu_begin();						\
86 	firmware_restrict_branch_speculation_start();			\
87 									\
88 	if (!efi_enabled(EFI_OLD_MEMMAP))				\
89 		efi_switch_mm(&efi_mm);					\
90 })
91 
92 #define arch_efi_call_virt(p, f, args...)				\
93 	efi_call((void *)p->f, args)					\
94 
95 #define arch_efi_call_virt_teardown()					\
96 ({									\
97 	if (!efi_enabled(EFI_OLD_MEMMAP))				\
98 		efi_switch_mm(efi_scratch.prev_mm);			\
99 									\
100 	firmware_restrict_branch_speculation_end();			\
101 	kernel_fpu_end();						\
102 })
103 
104 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
105 					u32 type, u64 attribute);
106 
107 #ifdef CONFIG_KASAN
108 /*
109  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
110  * only in kernel binary.  Since the EFI stub linked into a separate binary it
111  * doesn't have __memset().  So we should use standard memset from
112  * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
113  */
114 #undef memcpy
115 #undef memset
116 #undef memmove
117 #endif
118 
119 #endif /* CONFIG_X86_32 */
120 
121 extern struct efi_scratch efi_scratch;
122 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
123 extern int __init efi_memblock_x86_reserve_range(void);
124 extern pgd_t * __init efi_call_phys_prolog(void);
125 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
126 extern void __init efi_print_memmap(void);
127 extern void __init efi_memory_uc(u64 addr, unsigned long size);
128 extern void __init efi_map_region(efi_memory_desc_t *md);
129 extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
130 extern void efi_sync_low_kernel_mappings(void);
131 extern int __init efi_alloc_page_tables(void);
132 extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
133 extern void __init old_map_region(efi_memory_desc_t *md);
134 extern void __init runtime_code_page_mkexec(void);
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_switch_mm(struct mm_struct *mm);
141 extern void efi_recover_from_page_fault(unsigned long phys_addr);
142 extern void efi_free_boot_services(void);
143 extern void efi_reserve_boot_services(void);
144 
145 struct efi_setup_data {
146 	u64 fw_vendor;
147 	u64 runtime;
148 	u64 tables;
149 	u64 smbios;
150 	u64 reserved[8];
151 };
152 
153 extern u64 efi_setup;
154 
155 #ifdef CONFIG_EFI
156 
157 static inline bool efi_is_native(void)
158 {
159 	return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
160 }
161 
162 static inline bool efi_runtime_supported(void)
163 {
164 	if (efi_is_native())
165 		return true;
166 
167 	if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
168 		return true;
169 
170 	return false;
171 }
172 
173 extern struct console early_efi_console;
174 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
175 
176 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
177 
178 #ifdef CONFIG_EFI_MIXED
179 extern void efi_thunk_runtime_setup(void);
180 extern efi_status_t efi_thunk_set_virtual_address_map(
181 	void *phys_set_virtual_address_map,
182 	unsigned long memory_map_size,
183 	unsigned long descriptor_size,
184 	u32 descriptor_version,
185 	efi_memory_desc_t *virtual_map);
186 #else
187 static inline void efi_thunk_runtime_setup(void) {}
188 static inline efi_status_t efi_thunk_set_virtual_address_map(
189 	void *phys_set_virtual_address_map,
190 	unsigned long memory_map_size,
191 	unsigned long descriptor_size,
192 	u32 descriptor_version,
193 	efi_memory_desc_t *virtual_map)
194 {
195 	return EFI_SUCCESS;
196 }
197 #endif /* CONFIG_EFI_MIXED */
198 
199 
200 /* arch specific definitions used by the stub code */
201 
202 struct efi_config {
203 	u64 image_handle;
204 	u64 table;
205 	u64 runtime_services;
206 	u64 boot_services;
207 	u64 text_output;
208 	efi_status_t (*call)(unsigned long, ...);
209 	bool is64;
210 } __packed;
211 
212 __pure const struct efi_config *__efi_early(void);
213 
214 static inline bool efi_is_64bit(void)
215 {
216 	if (!IS_ENABLED(CONFIG_X86_64))
217 		return false;
218 
219 	if (!IS_ENABLED(CONFIG_EFI_MIXED))
220 		return true;
221 
222 	return __efi_early()->is64;
223 }
224 
225 #define efi_table_attr(table, attr, instance)				\
226 	(efi_is_64bit() ?						\
227 		((table##_64_t *)(unsigned long)instance)->attr :	\
228 		((table##_32_t *)(unsigned long)instance)->attr)
229 
230 #define efi_call_proto(protocol, f, instance, ...)			\
231 	__efi_early()->call(efi_table_attr(protocol, f, instance),	\
232 		instance, ##__VA_ARGS__)
233 
234 #define efi_call_early(f, ...)						\
235 	__efi_early()->call(efi_table_attr(efi_boot_services, f,	\
236 		__efi_early()->boot_services), __VA_ARGS__)
237 
238 #define __efi_call_early(f, ...)					\
239 	__efi_early()->call((unsigned long)f, __VA_ARGS__);
240 
241 #define efi_call_runtime(f, ...)					\
242 	__efi_early()->call(efi_table_attr(efi_runtime_services, f,	\
243 		__efi_early()->runtime_services), __VA_ARGS__)
244 
245 extern bool efi_reboot_required(void);
246 
247 #else
248 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
249 static inline bool efi_reboot_required(void)
250 {
251 	return false;
252 }
253 #endif /* CONFIG_EFI */
254 
255 #endif /* _ASM_X86_EFI_H */
256