1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2024 Arm Ltd
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #ifndef _MACHINE_CPU_FEAT_H_
29 #define _MACHINE_CPU_FEAT_H_
30
31 #include <sys/linker_set.h>
32
33 typedef enum {
34 ERRATA_UNKNOWN, /* Unknown erratum */
35 ERRATA_NONE, /* No errata for this feature on this system. */
36 ERRATA_AFFECTED, /* There is errata on this system. */
37 ERRATA_FW_MITIGAION, /* There is errata, and a firmware */
38 /* mitigation. The mitigation may need a */
39 /* kernel component. */
40 } cpu_feat_errata;
41
42 #define CPU_FEAT_STAGE_MASK 0x00000001
43 #define CPU_FEAT_EARLY_BOOT 0x00000000
44 #define CPU_FEAT_AFTER_DEV 0x00000001
45
46 #define CPU_FEAT_SCOPE_MASK 0x00000010
47 #define CPU_FEAT_PER_CPU 0x00000000
48 #define CPU_FEAT_SYSTEM 0x00000010
49
50 struct cpu_feat;
51
52 typedef bool (cpu_feat_check)(const struct cpu_feat *, u_int);
53 typedef bool (cpu_feat_has_errata)(const struct cpu_feat *, u_int,
54 u_int **, u_int *);
55 typedef void (cpu_feat_enable)(const struct cpu_feat *, cpu_feat_errata,
56 u_int *, u_int);
57
58 struct cpu_feat {
59 const char *feat_name;
60 cpu_feat_check *feat_check;
61 cpu_feat_has_errata *feat_has_errata;
62 cpu_feat_enable *feat_enable;
63 uint32_t feat_flags;
64 };
65 SET_DECLARE(cpu_feat_set, struct cpu_feat);
66
67 /*
68 * Allow drivers to mark an erratum as worked around, e.g. the Errata
69 * Management ABI may know the workaround isn't needed on a given system.
70 */
71 typedef cpu_feat_errata (*cpu_feat_errata_check_fn)(const struct cpu_feat *,
72 u_int);
73 void cpu_feat_register_errata_check(cpu_feat_errata_check_fn);
74
75 void enable_cpu_feat(uint32_t);
76
77 /* Check if an erratum is in the list of errata */
78 static inline bool
cpu_feat_has_erratum(u_int * errata_list,u_int errata_count,u_int erratum)79 cpu_feat_has_erratum(u_int *errata_list, u_int errata_count, u_int erratum)
80 {
81 for (u_int i = 0; i < errata_count; i++)
82 if (errata_list[0] == erratum)
83 return (true);
84
85 return (false);
86 }
87
88 #endif /* _MACHINE_CPU_FEAT_H_ */
89