tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1#ifndef _ASM_EFI_H
2#define _ASM_EFI_H
3
4#include <asm/boot.h>
5#include <asm/cpufeature.h>
6#include <asm/fpsimd.h>
7#include <asm/io.h>
8#include <asm/memory.h>
9#include <asm/mmu_context.h>
10#include <asm/neon.h>
11#include <asm/ptrace.h>
12#include <asm/tlbflush.h>
13
14#ifdef CONFIG_EFI
15extern void efi_init(void);
16#else
17#define efi_init()
18#endif
19
20int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
21int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
22
23#define arch_efi_call_virt_setup() \
24({ \
25 efi_virtmap_load(); \
26 __efi_fpsimd_begin(); \
27})
28
29#define arch_efi_call_virt(p, f, args...) \
30({ \
31 efi_##f##_t *__f; \
32 __f = p->f; \
33 __f(args); \
34})
35
36#define arch_efi_call_virt_teardown() \
37({ \
38 __efi_fpsimd_end(); \
39 efi_virtmap_unload(); \
40})
41
42#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
43
44/* arch specific definitions used by the stub code */
45
46/*
47 * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
48 * start of kernel and may not cross a 2MiB boundary. We set alignment to
49 * 2MiB so we know it won't cross a 2MiB boundary.
50 */
51#define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */
52
53/*
54 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
55 * kernel need greater alignment than we require the segments to be padded to.
56 */
57#define EFI_KIMG_ALIGN \
58 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
59
60/* on arm64, the FDT may be located anywhere in system RAM */
61static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
62{
63 return ULONG_MAX;
64}
65
66/*
67 * On arm64, we have to ensure that the initrd ends up in the linear region,
68 * which is a 1 GB aligned region of size '1UL << (VA_BITS - 1)' that is
69 * guaranteed to cover the kernel Image.
70 *
71 * Since the EFI stub is part of the kernel Image, we can relax the
72 * usual requirements in Documentation/arm64/booting.txt, which still
73 * apply to other bootloaders, and are required for some kernel
74 * configurations.
75 */
76static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
77 unsigned long image_addr)
78{
79 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS - 1));
80}
81
82#define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
83#define __efi_call_early(f, ...) f(__VA_ARGS__)
84#define efi_call_runtime(f, ...) sys_table_arg->runtime->f(__VA_ARGS__)
85#define efi_is_64bit() (true)
86
87#define efi_call_proto(protocol, f, instance, ...) \
88 ((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
89
90#define alloc_screen_info(x...) &screen_info
91#define free_screen_info(x...)
92
93/* redeclare as 'hidden' so the compiler will generate relative references */
94extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
95
96static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
97{
98}
99
100#define EFI_ALLOC_ALIGN SZ_64K
101
102/*
103 * On ARM systems, virtually remapped UEFI runtime services are set up in two
104 * distinct stages:
105 * - The stub retrieves the final version of the memory map from UEFI, populates
106 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
107 * service to communicate the new mapping to the firmware (Note that the new
108 * mapping is not live at this time)
109 * - During an early initcall(), the EFI system table is permanently remapped
110 * and the virtual remapping of the UEFI Runtime Services regions is loaded
111 * into a private set of page tables. If this all succeeds, the Runtime
112 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
113 */
114
115static inline void efi_set_pgd(struct mm_struct *mm)
116{
117 __switch_mm(mm);
118
119 if (system_uses_ttbr0_pan()) {
120 if (mm != current->active_mm) {
121 /*
122 * Update the current thread's saved ttbr0 since it is
123 * restored as part of a return from exception. Set
124 * the hardware TTBR0_EL1 using cpu_switch_mm()
125 * directly to enable potential errata workarounds.
126 */
127 update_saved_ttbr0(current, mm);
128 cpu_switch_mm(mm->pgd, mm);
129 } else {
130 /*
131 * Defer the switch to the current thread's TTBR0_EL1
132 * until uaccess_enable(). Restore the current
133 * thread's saved ttbr0 corresponding to its active_mm
134 * (if different from init_mm).
135 */
136 cpu_set_reserved_ttbr0();
137 if (current->active_mm != &init_mm)
138 update_saved_ttbr0(current, current->active_mm);
139 }
140 }
141}
142
143void efi_virtmap_load(void);
144void efi_virtmap_unload(void);
145
146#endif /* _ASM_EFI_H */