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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 /*
71  * On arm64, we have to ensure that the initrd ends up in the linear region,
72  * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
73  * guaranteed to cover the kernel Image.
74  *
75  * Since the EFI stub is part of the kernel Image, we can relax the
76  * usual requirements in Documentation/arm64/booting.rst, which still
77  * apply to other bootloaders, and are required for some kernel
78  * configurations.
79  */
efi_get_max_initrd_addr(unsigned long image_addr)80 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
81 {
82 	return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
83 }
84 
85 #define alloc_screen_info(x...)		&screen_info
86 
free_screen_info(struct screen_info * si)87 static inline void free_screen_info(struct screen_info *si)
88 {
89 }
90 
91 #define EFI_ALLOC_ALIGN		SZ_64K
92 
93 /*
94  * On ARM systems, virtually remapped UEFI runtime services are set up in two
95  * distinct stages:
96  * - The stub retrieves the final version of the memory map from UEFI, populates
97  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
98  *   service to communicate the new mapping to the firmware (Note that the new
99  *   mapping is not live at this time)
100  * - During an early initcall(), the EFI system table is permanently remapped
101  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
102  *   into a private set of page tables. If this all succeeds, the Runtime
103  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
104  */
105 
efi_set_pgd(struct mm_struct * mm)106 static inline void efi_set_pgd(struct mm_struct *mm)
107 {
108 	__switch_mm(mm);
109 
110 	if (system_uses_ttbr0_pan()) {
111 		if (mm != current->active_mm) {
112 			/*
113 			 * Update the current thread's saved ttbr0 since it is
114 			 * restored as part of a return from exception. Enable
115 			 * access to the valid TTBR0_EL1 and invoke the errata
116 			 * workaround directly since there is no return from
117 			 * exception when invoking the EFI run-time services.
118 			 */
119 			update_saved_ttbr0(current, mm);
120 			uaccess_ttbr0_enable();
121 			post_ttbr_update_workaround();
122 		} else {
123 			/*
124 			 * Defer the switch to the current thread's TTBR0_EL1
125 			 * until uaccess_enable(). Restore the current
126 			 * thread's saved ttbr0 corresponding to its active_mm
127 			 */
128 			uaccess_ttbr0_disable();
129 			update_saved_ttbr0(current, current->active_mm);
130 		}
131 	}
132 }
133 
134 void efi_virtmap_load(void);
135 void efi_virtmap_unload(void);
136 
efi_capsule_flush_cache_range(void * addr,int size)137 static inline void efi_capsule_flush_cache_range(void *addr, int size)
138 {
139 	dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
140 }
141 
142 #endif /* _ASM_EFI_H */
143