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 #else
18 #define efi_init()
19 #endif
20
21 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
22 int 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 raw_spin_lock(&efi_rt_lock); \
29 })
30
31 #define arch_efi_call_virt(p, f, args...) \
32 ({ \
33 efi_##f##_t *__f; \
34 __f = p->f; \
35 __efi_rt_asm_wrapper(__f, #f, args); \
36 })
37
38 #define arch_efi_call_virt_teardown() \
39 ({ \
40 raw_spin_unlock(&efi_rt_lock); \
41 __efi_fpsimd_end(); \
42 efi_virtmap_unload(); \
43 })
44
45 extern raw_spinlock_t efi_rt_lock;
46 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
47
48 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
49
50 /*
51 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
52 * And EFI shouldn't really play around with priority masking as it is not aware
53 * which priorities the OS has assigned to its interrupts.
54 */
55 #define arch_efi_save_flags(state_flags) \
56 ((void)((state_flags) = read_sysreg(daif)))
57
58 #define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
59
60
61 /* arch specific definitions used by the stub code */
62
63 /*
64 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
65 * kernel need greater alignment than we require the segments to be padded to.
66 */
67 #define EFI_KIMG_ALIGN \
68 (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
69
70 /* on arm64, the FDT may be located anywhere in system RAM */
efi_get_max_fdt_addr(unsigned long image_addr)71 static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
72 {
73 return ULONG_MAX;
74 }
75
76 /*
77 * On arm64, we have to ensure that the initrd ends up in the linear region,
78 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
79 * guaranteed to cover the kernel Image.
80 *
81 * Since the EFI stub is part of the kernel Image, we can relax the
82 * usual requirements in Documentation/arm64/booting.rst, which still
83 * apply to other bootloaders, and are required for some kernel
84 * configurations.
85 */
efi_get_max_initrd_addr(unsigned long image_addr)86 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
87 {
88 return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
89 }
90
91 #define alloc_screen_info(x...) &screen_info
92
free_screen_info(struct screen_info * si)93 static inline void free_screen_info(struct screen_info *si)
94 {
95 }
96
efifb_setup_from_dmi(struct screen_info * si,const char * opt)97 static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
98 {
99 }
100
101 #define EFI_ALLOC_ALIGN SZ_64K
102
103 /*
104 * On ARM systems, virtually remapped UEFI runtime services are set up in two
105 * distinct stages:
106 * - The stub retrieves the final version of the memory map from UEFI, populates
107 * the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
108 * service to communicate the new mapping to the firmware (Note that the new
109 * mapping is not live at this time)
110 * - During an early initcall(), the EFI system table is permanently remapped
111 * and the virtual remapping of the UEFI Runtime Services regions is loaded
112 * into a private set of page tables. If this all succeeds, the Runtime
113 * Services are enabled and the EFI_RUNTIME_SERVICES bit set.
114 */
115
efi_set_pgd(struct mm_struct * mm)116 static inline void efi_set_pgd(struct mm_struct *mm)
117 {
118 __switch_mm(mm);
119
120 if (system_uses_ttbr0_pan()) {
121 if (mm != current->active_mm) {
122 /*
123 * Update the current thread's saved ttbr0 since it is
124 * restored as part of a return from exception. Enable
125 * access to the valid TTBR0_EL1 and invoke the errata
126 * workaround directly since there is no return from
127 * exception when invoking the EFI run-time services.
128 */
129 update_saved_ttbr0(current, mm);
130 uaccess_ttbr0_enable();
131 post_ttbr_update_workaround();
132 } else {
133 /*
134 * Defer the switch to the current thread's TTBR0_EL1
135 * until uaccess_enable(). Restore the current
136 * thread's saved ttbr0 corresponding to its active_mm
137 */
138 uaccess_ttbr0_disable();
139 update_saved_ttbr0(current, current->active_mm);
140 }
141 }
142 }
143
144 void efi_virtmap_load(void);
145 void efi_virtmap_unload(void);
146
147 #endif /* _ASM_EFI_H */
148