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 #include <asm/vendor_extensions.h>
16
17 struct errata_info_t {
18 char name[32];
19 bool (*check_func)(unsigned long arch_id, unsigned long impid);
20 };
21
22 static bool errata_cip_453_check_func(unsigned long arch_id, unsigned long impid)
23 {
24 /*
25 * Affected cores:
26 * Architecture ID: 0x8000000000000007
27 * Implement ID: 0x20181004 <= impid <= 0x20191105
28 */
29 if (arch_id != 0x8000000000000007 ||
30 (impid < 0x20181004 || impid > 0x20191105))
31 return false;
32 return true;
33 }
34
35 static bool errata_cip_1200_check_func(unsigned long arch_id, unsigned long impid)
36 {
37 /*
38 * Affected cores:
39 * Architecture ID: 0x8000000000000007 or 0x1
40 * Implement ID: mimpid[23:0] <= 0x200630 and mimpid != 0x01200626
41 */
42 if (arch_id != 0x8000000000000007 && arch_id != 0x1)
43 return false;
44 if ((impid & 0xffffff) > 0x200630 || impid == 0x1200626)
45 return false;
46
47 #ifdef CONFIG_MMU
48 tlb_flush_all_threshold = 0;
49 #endif
50
51 return true;
52 }
53
54 static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
55 {
56 .name = "cip-453",
57 .check_func = errata_cip_453_check_func
58 },
59 {
60 .name = "cip-1200",
61 .check_func = errata_cip_1200_check_func
62 },
63 };
64
65 static u32 __init_or_module sifive_errata_probe(unsigned long archid,
66 unsigned long impid)
67 {
68 int idx;
69 u32 cpu_req_errata = 0;
70
71 for (idx = 0; idx < ERRATA_SIFIVE_NUMBER; idx++)
72 if (errata_list[idx].check_func(archid, impid))
73 cpu_req_errata |= (1U << idx);
74
75 return cpu_req_errata;
76 }
77
78 static void __init_or_module warn_miss_errata(u32 miss_errata)
79 {
80 int i;
81
82 pr_warn("----------------------------------------------------------------\n");
83 pr_warn("WARNING: Missing the following errata may cause potential issues\n");
84 for (i = 0; i < ERRATA_SIFIVE_NUMBER; i++)
85 if (miss_errata & 0x1 << i)
86 pr_warn("\tSiFive Errata[%d]:%s\n", i, errata_list[i].name);
87 pr_warn("Please enable the corresponding Kconfig to apply them\n");
88 pr_warn("----------------------------------------------------------------\n");
89 }
90
91 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
92 unsigned long archid, unsigned long impid,
93 unsigned int stage)
94 {
95 struct alt_entry *alt;
96 u32 cpu_req_errata;
97 u32 cpu_apply_errata = 0;
98 u32 tmp;
99
100 BUILD_BUG_ON(ERRATA_SIFIVE_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
101
102 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
103 return;
104
105 cpu_req_errata = sifive_errata_probe(archid, impid);
106
107 for (alt = begin; alt < end; alt++) {
108 if (alt->vendor_id != SIFIVE_VENDOR_ID)
109 continue;
110 if (alt->patch_id >= ERRATA_SIFIVE_NUMBER) {
111 WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id);
112 continue;
113 }
114
115 tmp = (1U << alt->patch_id);
116 if (cpu_req_errata & tmp) {
117 mutex_lock(&text_mutex);
118 patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
119 alt->alt_len);
120 mutex_unlock(&text_mutex);
121 cpu_apply_errata |= tmp;
122 }
123 }
124 if (stage != RISCV_ALTERNATIVES_MODULE &&
125 cpu_apply_errata != cpu_req_errata)
126 warn_miss_errata(cpu_req_errata - cpu_apply_errata);
127 }
128
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