xref: /linux/arch/riscv/include/asm/alternative.h (revision d6a5c562214f26e442c8ec3ff1e28e16675d1bcf)
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 void __init apply_boot_alternatives(void);
27 void __init apply_early_boot_alternatives(void);
28 void apply_module_alternatives(void *start, size_t length);
29 
30 struct alt_entry {
31 	void *old_ptr;		 /* address of original instruciton or data  */
32 	void *alt_ptr;		 /* address of replacement instruction or data */
33 	unsigned long vendor_id; /* cpu vendor id */
34 	unsigned long alt_len;   /* The replacement size */
35 	unsigned int errata_id;  /* The errata id */
36 } __packed;
37 
38 struct errata_checkfunc_id {
39 	unsigned long vendor_id;
40 	bool (*func)(struct alt_entry *alt);
41 };
42 
43 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
44 			      unsigned long archid, unsigned long impid,
45 			      unsigned int stage);
46 void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
47 			     unsigned long archid, unsigned long impid,
48 			     unsigned int stage);
49 
50 void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end,
51 				 unsigned int stage);
52 
53 #else /* CONFIG_RISCV_ALTERNATIVE */
54 
55 static inline void apply_boot_alternatives(void) { }
56 static inline void apply_early_boot_alternatives(void) { }
57 static inline void apply_module_alternatives(void *start, size_t length) { }
58 
59 #endif /* CONFIG_RISCV_ALTERNATIVE */
60 
61 #endif
62 #endif
63