1 #ifndef _ASM_EFI_H
2 #define _ASM_EFI_H
3
4 #include <asm/cpufeature.h>
5 #include <asm/io.h>
6 #include <asm/mmu_context.h>
7 #include <asm/neon.h>
8 #include <asm/ptrace.h>
9 #include <asm/tlbflush.h>
10
11 #ifdef CONFIG_EFI
12 extern void efi_init(void);
13 #else
14 #define efi_init()
15 #endif
16
17 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
18 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
19
20 #define arch_efi_call_virt_setup() \
21 ({ \
22 kernel_neon_begin(); \
23 efi_virtmap_load(); \
24 })
25
26 #define arch_efi_call_virt(p, f, args...) \
27 ({ \
28 efi_##f##_t *__f; \
29 __f = p->f; \
30 __f(args); \
31 })
32
33 #define arch_efi_call_virt_teardown() \
34 ({ \
35 efi_virtmap_unload(); \
36 kernel_neon_end(); \
37 })
38
39 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
40
41 /* arch specific definitions used by the stub code */
42
43 /*
44 * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
45 * start of kernel and may not cross a 2MiB boundary. We set alignment to
46 * 2MiB so we know it won't cross a 2MiB boundary.
47 */
48 #define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */
49 #define MAX_FDT_OFFSET SZ_512M
50
51 #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
52 #define __efi_call_early(f, ...) f(__VA_ARGS__)
53 #define efi_is_64bit() (true)
54
55 #define alloc_screen_info(x...) &screen_info
56 #define free_screen_info(x...)
57
58 /* redeclare as 'hidden' so the compiler will generate relative references */
59 extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
60
efifb_setup_from_dmi(struct screen_info * si,const char * opt)61 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
62 {
63 }
64
65 #define EFI_ALLOC_ALIGN SZ_64K
66
67 /*
68 * On ARM systems, virtually remapped UEFI runtime services are set up in two
69 * distinct stages:
70 * - The stub retrieves the final version of the memory map from UEFI, populates
71 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
72 * service to communicate the new mapping to the firmware (Note that the new
73 * mapping is not live at this time)
74 * - During an early initcall(), the EFI system table is permanently remapped
75 * and the virtual remapping of the UEFI Runtime Services regions is loaded
76 * into a private set of page tables. If this all succeeds, the Runtime
77 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
78 */
79
efi_set_pgd(struct mm_struct * mm)80 static inline void efi_set_pgd(struct mm_struct *mm)
81 {
82 __switch_mm(mm);
83
84 if (system_uses_ttbr0_pan()) {
85 if (mm != current->active_mm) {
86 /*
87 * Update the current thread's saved ttbr0 since it is
88 * restored as part of a return from exception. Enable
89 * access to the valid TTBR0_EL1 and invoke the errata
90 * workaround directly since there is no return from
91 * exception when invoking the EFI run-time services.
92 */
93 update_saved_ttbr0(current, mm);
94 uaccess_ttbr0_enable();
95 post_ttbr_update_workaround();
96 } else {
97 /*
98 * Defer the switch to the current thread's TTBR0_EL1
99 * until uaccess_enable(). Restore the current
100 * thread's saved ttbr0 corresponding to its active_mm
101 * (if different from init_mm).
102 */
103 uaccess_ttbr0_disable();
104 if (current->active_mm != &init_mm)
105 update_saved_ttbr0(current, current->active_mm);
106 }
107 }
108 }
109
110 void efi_virtmap_load(void);
111 void efi_virtmap_unload(void);
112
113 #endif /* _ASM_EFI_H */
114