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