1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2021 Sifive.
4 */
5
6 #ifndef __ASM_ALTERNATIVE_H
7 #define __ASM_ALTERNATIVE_H
8
9 #define ERRATA_STRING_LENGTH_MAX 32
10
11 #include <asm/alternative-macros.h>
12
13 #ifndef __ASSEMBLY__
14
15 #ifdef CONFIG_RISCV_ALTERNATIVE
16
17 #include <linux/init.h>
18 #include <linux/types.h>
19 #include <linux/stddef.h>
20 #include <asm/hwcap.h>
21
22 #define RISCV_ALTERNATIVES_BOOT 0 /* alternatives applied during regular boot */
23 #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */
24 #define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */
25
26 /* add the relative offset to the address of the offset to get the absolute address */
27 #define __ALT_PTR(a, f) ((void *)&(a)->f + (a)->f)
28 #define ALT_OLD_PTR(a) __ALT_PTR(a, old_offset)
29 #define ALT_ALT_PTR(a) __ALT_PTR(a, alt_offset)
30
31 void __init apply_boot_alternatives(void);
32 void __init apply_early_boot_alternatives(void);
33 void apply_module_alternatives(void *start, size_t length);
34
35 void riscv_alternative_fix_offsets(void *alt_ptr, unsigned int len,
36 int patch_offset);
37
38 struct alt_entry {
39 s32 old_offset; /* offset relative to original instruction or data */
40 s32 alt_offset; /* offset relative to replacement instruction or data */
41 u16 vendor_id; /* cpu vendor id */
42 u16 alt_len; /* The replacement size */
43 u32 errata_id; /* The errata id */
44 };
45
46 struct errata_checkfunc_id {
47 unsigned long vendor_id;
48 bool (*func)(struct alt_entry *alt);
49 };
50
51 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
52 unsigned long archid, unsigned long impid,
53 unsigned int stage);
54 void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
55 unsigned long archid, unsigned long impid,
56 unsigned int stage);
57
58 void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end,
59 unsigned int stage);
60
61 #else /* CONFIG_RISCV_ALTERNATIVE */
62
apply_boot_alternatives(void)63 static inline void apply_boot_alternatives(void) { }
apply_early_boot_alternatives(void)64 static inline void apply_early_boot_alternatives(void) { }
apply_module_alternatives(void * start,size_t length)65 static inline void apply_module_alternatives(void *start, size_t length) { }
66
67 #endif /* CONFIG_RISCV_ALTERNATIVE */
68
69 #endif
70 #endif
71