1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_EFI_H
3 #define _ASM_EFI_H
4
5 #include <asm/boot.h>
6 #include <asm/cpufeature.h>
7 #include <asm/fpsimd.h>
8 #include <asm/io.h>
9 #include <asm/memory.h>
10 #include <asm/mmu_context.h>
11 #include <asm/neon.h>
12 #include <asm/ptrace.h>
13 #include <asm/tlbflush.h>
14
15 #ifdef CONFIG_EFI
16 extern void efi_init(void);
17 #else
18 #define efi_init()
19 #endif
20
21 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
22 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
23
24 #define arch_efi_call_virt_setup() \
25 ({ \
26 efi_virtmap_load(); \
27 __efi_fpsimd_begin(); \
28 })
29
30 #define arch_efi_call_virt(p, f, args...) \
31 ({ \
32 efi_##f##_t *__f; \
33 __f = p->f; \
34 __efi_rt_asm_wrapper(__f, #f, args); \
35 })
36
37 #define arch_efi_call_virt_teardown() \
38 ({ \
39 __efi_fpsimd_end(); \
40 efi_virtmap_unload(); \
41 })
42
43 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
44
45 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
46
47 /*
48 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
49 * And EFI shouldn't really play around with priority masking as it is not aware
50 * which priorities the OS has assigned to its interrupts.
51 */
52 #define arch_efi_save_flags(state_flags) \
53 ((void)((state_flags) = read_sysreg(daif)))
54
55 #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
56
57
58 /* arch specific definitions used by the stub code */
59
60 /*
61 * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
62 * start of kernel and may not cross a 2MiB boundary. We set alignment to
63 * 2MiB so we know it won't cross a 2MiB boundary.
64 */
65 #define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */
66
67 /*
68 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
69 * kernel need greater alignment than we require the segments to be padded to.
70 */
71 #define EFI_KIMG_ALIGN \
72 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
73
74 /* on arm64, the FDT may be located anywhere in system RAM */
75 static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
76 {
77 return ULONG_MAX;
78 }
79
80 /*
81 * On arm64, we have to ensure that the initrd ends up in the linear region,
82 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
83 * guaranteed to cover the kernel Image.
84 *
85 * Since the EFI stub is part of the kernel Image, we can relax the
86 * usual requirements in Documentation/arm64/booting.rst, which still
87 * apply to other bootloaders, and are required for some kernel
88 * configurations.
89 */
90 static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
91 unsigned long image_addr)
92 {
93 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
94 }
95
96 #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
97 #define __efi_call_early(f, ...) f(__VA_ARGS__)
98 #define efi_call_runtime(f, ...) sys_table_arg->runtime->f(__VA_ARGS__)
99 #define efi_is_64bit() (true)
100
101 #define efi_table_attr(table, attr, instance) \
102 ((table##_t *)instance)->attr
103
104 #define efi_call_proto(protocol, f, instance, ...) \
105 ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
106
107 #define alloc_screen_info(x...) &screen_info
108
109 static inline void free_screen_info(efi_system_table_t *sys_table_arg,
110 struct screen_info *si)
111 {
112 }
113
114 /* redeclare as 'hidden' so the compiler will generate relative references */
115 extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
116
117 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
118 {
119 }
120
121 #define EFI_ALLOC_ALIGN SZ_64K
122
123 /*
124 * On ARM systems, virtually remapped UEFI runtime services are set up in two
125 * distinct stages:
126 * - The stub retrieves the final version of the memory map from UEFI, populates
127 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
128 * service to communicate the new mapping to the firmware (Note that the new
129 * mapping is not live at this time)
130 * - During an early initcall(), the EFI system table is permanently remapped
131 * and the virtual remapping of the UEFI Runtime Services regions is loaded
132 * into a private set of page tables. If this all succeeds, the Runtime
133 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
134 */
135
136 static inline void efi_set_pgd(struct mm_struct *mm)
137 {
138 __switch_mm(mm);
139
140 if (system_uses_ttbr0_pan()) {
141 if (mm != current->active_mm) {
142 /*
143 * Update the current thread's saved ttbr0 since it is
144 * restored as part of a return from exception. Enable
145 * access to the valid TTBR0_EL1 and invoke the errata
146 * workaround directly since there is no return from
147 * exception when invoking the EFI run-time services.
148 */
149 update_saved_ttbr0(current, mm);
150 uaccess_ttbr0_enable();
151 post_ttbr_update_workaround();
152 } else {
153 /*
154 * Defer the switch to the current thread's TTBR0_EL1
155 * until uaccess_enable(). Restore the current
156 * thread's saved ttbr0 corresponding to its active_mm
157 */
158 uaccess_ttbr0_disable();
159 update_saved_ttbr0(current, current->active_mm);
160 }
161 }
162 }
163
164 void efi_virtmap_load(void);
165 void efi_virtmap_unload(void);
166
167 #endif /* _ASM_EFI_H */