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
18 bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg);
19 #else
20 #define efi_init()
21
22 static inline
23 bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg)
24 {
25 return false;
26 }
27 #endif
28
29 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
30 int 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
37 extern u64 *efi_rt_stack_top;
38 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
39
40 void arch_efi_call_virt_setup(void);
41 void 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 */
83 static 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
88 static 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
106 extern 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
121 static 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
149 void efi_virtmap_load(void);
150 void efi_virtmap_unload(void);
151
152 static 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
157 efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
158
159 void efi_icache_sync(unsigned long start, unsigned long end);
160
161 #endif /* _ASM_EFI_H */
162
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