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