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