1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2021 Sifive.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/memory.h>
8 #include <linux/module.h>
9 #include <linux/string.h>
10 #include <linux/bug.h>
11 #include <asm/patch.h>
12 #include <asm/alternative.h>
13 #include <asm/vendorid_list.h>
14 #include <asm/errata_list.h>
15
16 struct errata_info_t {
17 char name[ERRATA_STRING_LENGTH_MAX];
18 bool (*check_func)(unsigned long arch_id, unsigned long impid);
19 };
20
errata_cip_453_check_func(unsigned long arch_id,unsigned long impid)21 static bool errata_cip_453_check_func(unsigned long arch_id, unsigned long impid)
22 {
23 /*
24 * Affected cores:
25 * Architecture ID: 0x8000000000000007
26 * Implement ID: 0x20181004 <= impid <= 0x20191105
27 */
28 if (arch_id != 0x8000000000000007 ||
29 (impid < 0x20181004 || impid > 0x20191105))
30 return false;
31 return true;
32 }
33
errata_cip_1200_check_func(unsigned long arch_id,unsigned long impid)34 static bool errata_cip_1200_check_func(unsigned long arch_id, unsigned long impid)
35 {
36 /*
37 * Affected cores:
38 * Architecture ID: 0x8000000000000007 or 0x1
39 * Implement ID: mimpid[23:0] <= 0x200630 and mimpid != 0x01200626
40 */
41 if (arch_id != 0x8000000000000007 && arch_id != 0x1)
42 return false;
43 if ((impid & 0xffffff) > 0x200630 || impid == 0x1200626)
44 return false;
45 return true;
46 }
47
48 static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
49 {
50 .name = "cip-453",
51 .check_func = errata_cip_453_check_func
52 },
53 {
54 .name = "cip-1200",
55 .check_func = errata_cip_1200_check_func
56 },
57 };
58
sifive_errata_probe(unsigned long archid,unsigned long impid)59 static u32 __init_or_module sifive_errata_probe(unsigned long archid,
60 unsigned long impid)
61 {
62 int idx;
63 u32 cpu_req_errata = 0;
64
65 for (idx = 0; idx < ERRATA_SIFIVE_NUMBER; idx++)
66 if (errata_list[idx].check_func(archid, impid))
67 cpu_req_errata |= (1U << idx);
68
69 return cpu_req_errata;
70 }
71
warn_miss_errata(u32 miss_errata)72 static void __init_or_module warn_miss_errata(u32 miss_errata)
73 {
74 int i;
75
76 pr_warn("----------------------------------------------------------------\n");
77 pr_warn("WARNING: Missing the following errata may cause potential issues\n");
78 for (i = 0; i < ERRATA_SIFIVE_NUMBER; i++)
79 if (miss_errata & 0x1 << i)
80 pr_warn("\tSiFive Errata[%d]:%s\n", i, errata_list[i].name);
81 pr_warn("Please enable the corresponding Kconfig to apply them\n");
82 pr_warn("----------------------------------------------------------------\n");
83 }
84
sifive_errata_patch_func(struct alt_entry * begin,struct alt_entry * end,unsigned long archid,unsigned long impid,unsigned int stage)85 void __init_or_module sifive_errata_patch_func(struct alt_entry *begin,
86 struct alt_entry *end,
87 unsigned long archid,
88 unsigned long impid,
89 unsigned int stage)
90 {
91 struct alt_entry *alt;
92 u32 cpu_req_errata;
93 u32 cpu_apply_errata = 0;
94 u32 tmp;
95
96 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
97 return;
98
99 cpu_req_errata = sifive_errata_probe(archid, impid);
100
101 for (alt = begin; alt < end; alt++) {
102 if (alt->vendor_id != SIFIVE_VENDOR_ID)
103 continue;
104 if (alt->errata_id >= ERRATA_SIFIVE_NUMBER) {
105 WARN(1, "This errata id:%d is not in kernel errata list", alt->errata_id);
106 continue;
107 }
108
109 tmp = (1U << alt->errata_id);
110 if (cpu_req_errata & tmp) {
111 mutex_lock(&text_mutex);
112 patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
113 alt->alt_len);
114 mutex_unlock(&text_mutex);
115 cpu_apply_errata |= tmp;
116 }
117 }
118 if (stage != RISCV_ALTERNATIVES_MODULE &&
119 cpu_apply_errata != cpu_req_errata)
120 warn_miss_errata(cpu_req_errata - cpu_apply_errata);
121 }
122