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 bool has_bti);
32
33 #define arch_efi_call_virt_setup() \
34 ({ \
35 efi_virtmap_load(); \
36 __efi_fpsimd_begin(); \
37 raw_spin_lock(&efi_rt_lock); \
38 })
39
40 #undef arch_efi_call_virt
41 #define arch_efi_call_virt(p, f, args...) \
42 __efi_rt_asm_wrapper((p)->f, #f, args)
43
44 #define arch_efi_call_virt_teardown() \
45 ({ \
46 raw_spin_unlock(&efi_rt_lock); \
47 __efi_fpsimd_end(); \
48 efi_virtmap_unload(); \
49 })
50
51 extern raw_spinlock_t efi_rt_lock;
52 extern u64 *efi_rt_stack_top;
53 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
54
55 /*
56 * efi_rt_stack_top[-1] contains the value the stack pointer had before
57 * switching to the EFI runtime stack.
58 */
59 #define current_in_efi() \
60 (!preemptible() && efi_rt_stack_top != NULL && \
61 on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
62
63 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
64
65 /*
66 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
67 * And EFI shouldn't really play around with priority masking as it is not aware
68 * which priorities the OS has assigned to its interrupts.
69 */
70 #define arch_efi_save_flags(state_flags) \
71 ((void)((state_flags) = read_sysreg(daif)))
72
73 #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
74
75
76 /* arch specific definitions used by the stub code */
77
78 /*
79 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
80 * kernel need greater alignment than we require the segments to be padded to.
81 */
82 #define EFI_KIMG_ALIGN \
83 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
84
85 /*
86 * On arm64, we have to ensure that the initrd ends up in the linear region,
87 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
88 * guaranteed to cover the kernel Image.
89 *
90 * Since the EFI stub is part of the kernel Image, we can relax the
91 * usual requirements in Documentation/arm64/booting.rst, which still
92 * apply to other bootloaders, and are required for some kernel
93 * configurations.
94 */
efi_get_max_initrd_addr(unsigned long image_addr)95 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
96 {
97 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
98 }
99
efi_get_kimg_min_align(void)100 static inline unsigned long efi_get_kimg_min_align(void)
101 {
102 extern bool efi_nokaslr;
103
104 /*
105 * Although relocatable kernels can fix up the misalignment with
106 * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are
107 * subtly out of sync with those recorded in the vmlinux when kaslr is
108 * disabled but the image required relocation anyway. Therefore retain
109 * 2M alignment if KASLR was explicitly disabled, even if it was not
110 * going to be activated to begin with.
111 */
112 return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
113 }
114
115 #define EFI_ALLOC_ALIGN SZ_64K
116 #define EFI_ALLOC_LIMIT ((1UL << 48) - 1)
117
118 extern unsigned long primary_entry_offset(void);
119
120 /*
121 * On ARM systems, virtually remapped UEFI runtime services are set up in two
122 * distinct stages:
123 * - The stub retrieves the final version of the memory map from UEFI, populates
124 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
125 * service to communicate the new mapping to the firmware (Note that the new
126 * mapping is not live at this time)
127 * - During an early initcall(), the EFI system table is permanently remapped
128 * and the virtual remapping of the UEFI Runtime Services regions is loaded
129 * into a private set of page tables. If this all succeeds, the Runtime
130 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
131 */
132
efi_set_pgd(struct mm_struct * mm)133 static inline void efi_set_pgd(struct mm_struct *mm)
134 {
135 __switch_mm(mm);
136
137 if (system_uses_ttbr0_pan()) {
138 if (mm != current->active_mm) {
139 /*
140 * Update the current thread's saved ttbr0 since it is
141 * restored as part of a return from exception. Enable
142 * access to the valid TTBR0_EL1 and invoke the errata
143 * workaround directly since there is no return from
144 * exception when invoking the EFI run-time services.
145 */
146 update_saved_ttbr0(current, mm);
147 uaccess_ttbr0_enable();
148 post_ttbr_update_workaround();
149 } else {
150 /*
151 * Defer the switch to the current thread's TTBR0_EL1
152 * until uaccess_enable(). Restore the current
153 * thread's saved ttbr0 corresponding to its active_mm
154 */
155 uaccess_ttbr0_disable();
156 update_saved_ttbr0(current, current->active_mm);
157 }
158 }
159 }
160
161 void efi_virtmap_load(void);
162 void efi_virtmap_unload(void);
163
efi_capsule_flush_cache_range(void * addr,int size)164 static inline void efi_capsule_flush_cache_range(void *addr, int size)
165 {
166 dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
167 }
168
169 #endif /* _ASM_EFI_H */
170