xref: /linux/arch/arm64/include/asm/efi.h (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
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 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
18 #else
19 #define efi_init()
20 #endif
21 
22 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
23 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
24 
25 #define arch_efi_call_virt_setup()					\
26 ({									\
27 	efi_virtmap_load();						\
28 	__efi_fpsimd_begin();						\
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 	__efi_fpsimd_end();						\
41 	efi_virtmap_unload();						\
42 })
43 
44 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
45 
46 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
47 
48 /*
49  * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
50  * And EFI shouldn't really play around with priority masking as it is not aware
51  * which priorities the OS has assigned to its interrupts.
52  */
53 #define arch_efi_save_flags(state_flags)		\
54 	((void)((state_flags) = read_sysreg(daif)))
55 
56 #define arch_efi_restore_flags(state_flags)	write_sysreg(state_flags, daif)
57 
58 
59 /* arch specific definitions used by the stub code */
60 
61 /*
62  * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
63  * kernel need greater alignment than we require the segments to be padded to.
64  */
65 #define EFI_KIMG_ALIGN	\
66 	(SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
67 
68 /*
69  * On arm64, we have to ensure that the initrd ends up in the linear region,
70  * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
71  * guaranteed to cover the kernel Image.
72  *
73  * Since the EFI stub is part of the kernel Image, we can relax the
74  * usual requirements in Documentation/arm64/booting.rst, which still
75  * apply to other bootloaders, and are required for some kernel
76  * configurations.
77  */
78 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
79 {
80 	return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
81 }
82 
83 #define alloc_screen_info(x...)		&screen_info
84 
85 static inline void free_screen_info(struct screen_info *si)
86 {
87 }
88 
89 #define EFI_ALLOC_ALIGN		SZ_64K
90 
91 /*
92  * On ARM systems, virtually remapped UEFI runtime services are set up in two
93  * distinct stages:
94  * - The stub retrieves the final version of the memory map from UEFI, populates
95  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
96  *   service to communicate the new mapping to the firmware (Note that the new
97  *   mapping is not live at this time)
98  * - During an early initcall(), the EFI system table is permanently remapped
99  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
100  *   into a private set of page tables. If this all succeeds, the Runtime
101  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
102  */
103 
104 static inline void efi_set_pgd(struct mm_struct *mm)
105 {
106 	__switch_mm(mm);
107 
108 	if (system_uses_ttbr0_pan()) {
109 		if (mm != current->active_mm) {
110 			/*
111 			 * Update the current thread's saved ttbr0 since it is
112 			 * restored as part of a return from exception. Enable
113 			 * access to the valid TTBR0_EL1 and invoke the errata
114 			 * workaround directly since there is no return from
115 			 * exception when invoking the EFI run-time services.
116 			 */
117 			update_saved_ttbr0(current, mm);
118 			uaccess_ttbr0_enable();
119 			post_ttbr_update_workaround();
120 		} else {
121 			/*
122 			 * Defer the switch to the current thread's TTBR0_EL1
123 			 * until uaccess_enable(). Restore the current
124 			 * thread's saved ttbr0 corresponding to its active_mm
125 			 */
126 			uaccess_ttbr0_disable();
127 			update_saved_ttbr0(current, current->active_mm);
128 		}
129 	}
130 }
131 
132 void efi_virtmap_load(void);
133 void efi_virtmap_unload(void);
134 
135 static inline void efi_capsule_flush_cache_range(void *addr, int size)
136 {
137 	dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
138 }
139 
140 #endif /* _ASM_EFI_H */
141