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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
16extern void efi_init(void);
17#else
18#define efi_init()
19#endif
20
21int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
22int 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
43efi_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 */
75static 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 */
90static 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
109static 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 */
115extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
116
117static 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
136static 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
164void efi_virtmap_load(void);
165void efi_virtmap_unload(void);
166
167#endif /* _ASM_EFI_H */
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
16extern void efi_init(void);
17
18bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg);
19#else
20#define efi_init()
21
22static inline
23bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg)
24{
25 return false;
26}
27#endif
28
29int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
30int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md,
31 bool has_bti);
32
33#undef arch_efi_call_virt
34#define arch_efi_call_virt(p, f, args...) \
35 __efi_rt_asm_wrapper((p)->f, #f, args)
36
37extern u64 *efi_rt_stack_top;
38efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
39
40void arch_efi_call_virt_setup(void);
41void arch_efi_call_virt_teardown(void);
42
43/*
44 * efi_rt_stack_top[-1] contains the value the stack pointer had before
45 * switching to the EFI runtime stack.
46 */
47#define current_in_efi() \
48 (!preemptible() && efi_rt_stack_top != NULL && \
49 on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
50
51#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
52
53/*
54 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
55 * And EFI shouldn't really play around with priority masking as it is not aware
56 * which priorities the OS has assigned to its interrupts.
57 */
58#define arch_efi_save_flags(state_flags) \
59 ((void)((state_flags) = read_sysreg(daif)))
60
61#define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
62
63
64/* arch specific definitions used by the stub code */
65
66/*
67 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
68 * kernel need greater alignment than we require the segments to be padded to.
69 */
70#define EFI_KIMG_ALIGN \
71 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
72
73/*
74 * On arm64, we have to ensure that the initrd ends up in the linear region,
75 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
76 * guaranteed to cover the kernel Image.
77 *
78 * Since the EFI stub is part of the kernel Image, we can relax the
79 * usual requirements in Documentation/arch/arm64/booting.rst, which still
80 * apply to other bootloaders, and are required for some kernel
81 * configurations.
82 */
83static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
84{
85 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
86}
87
88static inline unsigned long efi_get_kimg_min_align(void)
89{
90 extern bool efi_nokaslr;
91
92 /*
93 * Although relocatable kernels can fix up the misalignment with
94 * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are
95 * subtly out of sync with those recorded in the vmlinux when kaslr is
96 * disabled but the image required relocation anyway. Therefore retain
97 * 2M alignment if KASLR was explicitly disabled, even if it was not
98 * going to be activated to begin with.
99 */
100 return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
101}
102
103#define EFI_ALLOC_ALIGN SZ_64K
104#define EFI_ALLOC_LIMIT ((1UL << 48) - 1)
105
106extern unsigned long primary_entry_offset(void);
107
108/*
109 * On ARM systems, virtually remapped UEFI runtime services are set up in two
110 * distinct stages:
111 * - The stub retrieves the final version of the memory map from UEFI, populates
112 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
113 * service to communicate the new mapping to the firmware (Note that the new
114 * mapping is not live at this time)
115 * - During an early initcall(), the EFI system table is permanently remapped
116 * and the virtual remapping of the UEFI Runtime Services regions is loaded
117 * into a private set of page tables. If this all succeeds, the Runtime
118 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
119 */
120
121static inline void efi_set_pgd(struct mm_struct *mm)
122{
123 __switch_mm(mm);
124
125 if (system_uses_ttbr0_pan()) {
126 if (mm != current->active_mm) {
127 /*
128 * Update the current thread's saved ttbr0 since it is
129 * restored as part of a return from exception. Enable
130 * access to the valid TTBR0_EL1 and invoke the errata
131 * workaround directly since there is no return from
132 * exception when invoking the EFI run-time services.
133 */
134 update_saved_ttbr0(current, mm);
135 uaccess_ttbr0_enable();
136 post_ttbr_update_workaround();
137 } else {
138 /*
139 * Defer the switch to the current thread's TTBR0_EL1
140 * until uaccess_enable(). Restore the current
141 * thread's saved ttbr0 corresponding to its active_mm
142 */
143 uaccess_ttbr0_disable();
144 update_saved_ttbr0(current, current->active_mm);
145 }
146 }
147}
148
149void efi_virtmap_load(void);
150void efi_virtmap_unload(void);
151
152static inline void efi_capsule_flush_cache_range(void *addr, int size)
153{
154 dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
155}
156
157efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
158
159void efi_icache_sync(unsigned long start, unsigned long end);
160
161#endif /* _ASM_EFI_H */