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#else
18#define efi_init()
19#endif
20
21int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
22int 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
45extern raw_spinlock_t efi_rt_lock;
46efi_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 */
71static 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 */
86static 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
93static inline void free_screen_info(struct screen_info *si)
94{
95}
96
97static 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
116static 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
144void efi_virtmap_load(void);
145void efi_virtmap_unload(void);
146
147#endif /* _ASM_EFI_H */
148