1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2021 Sifive.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/string.h>
9 #include <linux/bug.h>
10 #include <asm/patch.h>
11 #include <asm/alternative.h>
12 #include <asm/vendorid_list.h>
13 #include <asm/errata_list.h>
14
15 struct errata_info_t {
16 char name[ERRATA_STRING_LENGTH_MAX];
17 bool (*check_func)(unsigned long arch_id, unsigned long impid);
18 };
19
errata_cip_453_check_func(unsigned long arch_id,unsigned long impid)20 static bool errata_cip_453_check_func(unsigned long arch_id, unsigned long impid)
21 {
22 /*
23 * Affected cores:
24 * Architecture ID: 0x8000000000000007
25 * Implement ID: 0x20181004 <= impid <= 0x20191105
26 */
27 if (arch_id != 0x8000000000000007 ||
28 (impid < 0x20181004 || impid > 0x20191105))
29 return false;
30 return true;
31 }
32
errata_cip_1200_check_func(unsigned long arch_id,unsigned long impid)33 static bool errata_cip_1200_check_func(unsigned long arch_id, unsigned long impid)
34 {
35 /*
36 * Affected cores:
37 * Architecture ID: 0x8000000000000007 or 0x1
38 * Implement ID: mimpid[23:0] <= 0x200630 and mimpid != 0x01200626
39 */
40 if (arch_id != 0x8000000000000007 && arch_id != 0x1)
41 return false;
42 if ((impid & 0xffffff) > 0x200630 || impid == 0x1200626)
43 return false;
44 return true;
45 }
46
47 static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
48 {
49 .name = "cip-453",
50 .check_func = errata_cip_453_check_func
51 },
52 {
53 .name = "cip-1200",
54 .check_func = errata_cip_1200_check_func
55 },
56 };
57
sifive_errata_probe(unsigned long archid,unsigned long impid)58 static u32 __init_or_module sifive_errata_probe(unsigned long archid,
59 unsigned long impid)
60 {
61 int idx;
62 u32 cpu_req_errata = 0;
63
64 for (idx = 0; idx < ERRATA_SIFIVE_NUMBER; idx++)
65 if (errata_list[idx].check_func(archid, impid))
66 cpu_req_errata |= (1U << idx);
67
68 return cpu_req_errata;
69 }
70
warn_miss_errata(u32 miss_errata)71 static void __init_or_module warn_miss_errata(u32 miss_errata)
72 {
73 int i;
74
75 pr_warn("----------------------------------------------------------------\n");
76 pr_warn("WARNING: Missing the following errata may cause potential issues\n");
77 for (i = 0; i < ERRATA_SIFIVE_NUMBER; i++)
78 if (miss_errata & 0x1 << i)
79 pr_warn("\tSiFive Errata[%d]:%s\n", i, errata_list[i].name);
80 pr_warn("Please enable the corresponding Kconfig to apply them\n");
81 pr_warn("----------------------------------------------------------------\n");
82 }
83
sifive_errata_patch_func(struct alt_entry * begin,struct alt_entry * end,unsigned long archid,unsigned long impid,unsigned int stage)84 void __init_or_module sifive_errata_patch_func(struct alt_entry *begin,
85 struct alt_entry *end,
86 unsigned long archid,
87 unsigned long impid,
88 unsigned int stage)
89 {
90 struct alt_entry *alt;
91 u32 cpu_req_errata;
92 u32 cpu_apply_errata = 0;
93 u32 tmp;
94
95 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
96 return;
97
98 cpu_req_errata = sifive_errata_probe(archid, impid);
99
100 for (alt = begin; alt < end; alt++) {
101 if (alt->vendor_id != SIFIVE_VENDOR_ID)
102 continue;
103 if (alt->errata_id >= ERRATA_SIFIVE_NUMBER) {
104 WARN(1, "This errata id:%d is not in kernel errata list", alt->errata_id);
105 continue;
106 }
107
108 tmp = (1U << alt->errata_id);
109 if (cpu_req_errata & tmp) {
110 patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
111 cpu_apply_errata |= tmp;
112 }
113 }
114 if (stage != RISCV_ALTERNATIVES_MODULE &&
115 cpu_apply_errata != cpu_req_errata)
116 warn_miss_errata(cpu_req_errata - cpu_apply_errata);
117 }
118