xref: /linux/arch/arm64/include/asm/efi.h (revision fb2ac84f8acccdec644d26dfc8ba6554f30cd6c0)
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 })
29 
30 #undef arch_efi_call_virt
31 #define arch_efi_call_virt(p, f, args...)				\
32 	__efi_rt_asm_wrapper((p)->f, #f, args)
33 
34 #define arch_efi_call_virt_teardown()					\
35 ({									\
36 	__efi_fpsimd_end();						\
37 	efi_virtmap_unload();						\
38 })
39 
40 efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
41 
42 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
43 
44 /*
45  * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
46  * And EFI shouldn't really play around with priority masking as it is not aware
47  * which priorities the OS has assigned to its interrupts.
48  */
49 #define arch_efi_save_flags(state_flags)		\
50 	((void)((state_flags) = read_sysreg(daif)))
51 
52 #define arch_efi_restore_flags(state_flags)	write_sysreg(state_flags, daif)
53 
54 
55 /* arch specific definitions used by the stub code */
56 
57 /*
58  * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
59  * kernel need greater alignment than we require the segments to be padded to.
60  */
61 #define EFI_KIMG_ALIGN	\
62 	(SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
63 
64 /*
65  * On arm64, we have to ensure that the initrd ends up in the linear region,
66  * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
67  * guaranteed to cover the kernel Image.
68  *
69  * Since the EFI stub is part of the kernel Image, we can relax the
70  * usual requirements in Documentation/arm64/booting.rst, which still
71  * apply to other bootloaders, and are required for some kernel
72  * configurations.
73  */
74 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
75 {
76 	return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
77 }
78 
79 #define alloc_screen_info(x...)		&screen_info
80 
81 static inline void free_screen_info(struct screen_info *si)
82 {
83 }
84 
85 #define EFI_ALLOC_ALIGN		SZ_64K
86 
87 /*
88  * On ARM systems, virtually remapped UEFI runtime services are set up in two
89  * distinct stages:
90  * - The stub retrieves the final version of the memory map from UEFI, populates
91  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
92  *   service to communicate the new mapping to the firmware (Note that the new
93  *   mapping is not live at this time)
94  * - During an early initcall(), the EFI system table is permanently remapped
95  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
96  *   into a private set of page tables. If this all succeeds, the Runtime
97  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
98  */
99 
100 static inline void efi_set_pgd(struct mm_struct *mm)
101 {
102 	__switch_mm(mm);
103 
104 	if (system_uses_ttbr0_pan()) {
105 		if (mm != current->active_mm) {
106 			/*
107 			 * Update the current thread's saved ttbr0 since it is
108 			 * restored as part of a return from exception. Enable
109 			 * access to the valid TTBR0_EL1 and invoke the errata
110 			 * workaround directly since there is no return from
111 			 * exception when invoking the EFI run-time services.
112 			 */
113 			update_saved_ttbr0(current, mm);
114 			uaccess_ttbr0_enable();
115 			post_ttbr_update_workaround();
116 		} else {
117 			/*
118 			 * Defer the switch to the current thread's TTBR0_EL1
119 			 * until uaccess_enable(). Restore the current
120 			 * thread's saved ttbr0 corresponding to its active_mm
121 			 */
122 			uaccess_ttbr0_disable();
123 			update_saved_ttbr0(current, current->active_mm);
124 		}
125 	}
126 }
127 
128 void efi_virtmap_load(void);
129 void efi_virtmap_unload(void);
130 
131 static inline void efi_capsule_flush_cache_range(void *addr, int size)
132 {
133 	dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
134 }
135 
136 #endif /* _ASM_EFI_H */
137