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
16extern void efi_init(void);
17
18bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg);
19#else
20#define efi_init()
21
22static inline
23bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg)
24{
25	return false;
26}
27#endif
28
29int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
30int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md,
31				bool has_bti);
32
33#undef arch_efi_call_virt
34#define arch_efi_call_virt(p, f, args...)				\
35	__efi_rt_asm_wrapper((p)->f, #f, args)
36
37extern u64 *efi_rt_stack_top;
38efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
39
40void arch_efi_call_virt_setup(void);
41void arch_efi_call_virt_teardown(void);
42
43/*
44 * efi_rt_stack_top[-1] contains the value the stack pointer had before
45 * switching to the EFI runtime stack.
46 */
47#define current_in_efi()						\
48	(!preemptible() && efi_rt_stack_top != NULL &&			\
49	 on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
50
51#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
52
53/*
54 * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
55 * And EFI shouldn't really play around with priority masking as it is not aware
56 * which priorities the OS has assigned to its interrupts.
57 */
58#define arch_efi_save_flags(state_flags)		\
59	((void)((state_flags) = read_sysreg(daif)))
60
61#define arch_efi_restore_flags(state_flags)	write_sysreg(state_flags, daif)
62
63
64/* arch specific definitions used by the stub code */
65
66/*
67 * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
68 * kernel need greater alignment than we require the segments to be padded to.
69 */
70#define EFI_KIMG_ALIGN	\
71	(SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
72
73/*
74 * On arm64, we have to ensure that the initrd ends up in the linear region,
75 * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
76 * guaranteed to cover the kernel Image.
77 *
78 * Since the EFI stub is part of the kernel Image, we can relax the
79 * usual requirements in Documentation/arch/arm64/booting.rst, which still
80 * apply to other bootloaders, and are required for some kernel
81 * configurations.
82 */
83static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
84{
85	return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
86}
87
88static inline unsigned long efi_get_kimg_min_align(void)
89{
90	extern bool efi_nokaslr;
91
92	/*
93	 * Although relocatable kernels can fix up the misalignment with
94	 * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are
95	 * subtly out of sync with those recorded in the vmlinux when kaslr is
96	 * disabled but the image required relocation anyway. Therefore retain
97	 * 2M alignment if KASLR was explicitly disabled, even if it was not
98	 * going to be activated to begin with.
99	 */
100	return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
101}
102
103#define EFI_ALLOC_ALIGN		SZ_64K
104#define EFI_ALLOC_LIMIT		((1UL << 48) - 1)
105
106extern unsigned long primary_entry_offset(void);
107
108/*
109 * On ARM systems, virtually remapped UEFI runtime services are set up in two
110 * distinct stages:
111 * - The stub retrieves the final version of the memory map from UEFI, populates
112 *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
113 *   service to communicate the new mapping to the firmware (Note that the new
114 *   mapping is not live at this time)
115 * - During an early initcall(), the EFI system table is permanently remapped
116 *   and the virtual remapping of the UEFI Runtime Services regions is loaded
117 *   into a private set of page tables. If this all succeeds, the Runtime
118 *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
119 */
120
121static inline void efi_set_pgd(struct mm_struct *mm)
122{
123	__switch_mm(mm);
124
125	if (system_uses_ttbr0_pan()) {
126		if (mm != current->active_mm) {
127			/*
128			 * Update the current thread's saved ttbr0 since it is
129			 * restored as part of a return from exception. Enable
130			 * access to the valid TTBR0_EL1 and invoke the errata
131			 * workaround directly since there is no return from
132			 * exception when invoking the EFI run-time services.
133			 */
134			update_saved_ttbr0(current, mm);
135			uaccess_ttbr0_enable();
136			post_ttbr_update_workaround();
137		} else {
138			/*
139			 * Defer the switch to the current thread's TTBR0_EL1
140			 * until uaccess_enable(). Restore the current
141			 * thread's saved ttbr0 corresponding to its active_mm
142			 */
143			uaccess_ttbr0_disable();
144			update_saved_ttbr0(current, current->active_mm);
145		}
146	}
147}
148
149void efi_virtmap_load(void);
150void efi_virtmap_unload(void);
151
152static inline void efi_capsule_flush_cache_range(void *addr, int size)
153{
154	dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size);
155}
156
157efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
158
159void efi_icache_sync(unsigned long start, unsigned long end);
160
161#endif /* _ASM_EFI_H */
162