1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2021 Heiko Stuebner <heiko@sntech.de>
4 */
5
6 #include <linux/bug.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/string.h>
10 #include <linux/uaccess.h>
11 #include <asm/alternative.h>
12 #include <asm/cacheflush.h>
13 #include <asm/errata_list.h>
14 #include <asm/patch.h>
15 #include <asm/vendorid_list.h>
16
17 struct errata_info {
18 char name[ERRATA_STRING_LENGTH_MAX];
19 bool (*check_func)(unsigned long arch_id, unsigned long impid);
20 unsigned int stage;
21 };
22
errata_mt_check_func(unsigned long arch_id,unsigned long impid)23 static bool errata_mt_check_func(unsigned long arch_id, unsigned long impid)
24 {
25 if (arch_id != 0 || impid != 0)
26 return false;
27 return true;
28 }
29
30 static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = {
31 {
32 .name = "memory-types",
33 .stage = RISCV_ALTERNATIVES_EARLY_BOOT,
34 .check_func = errata_mt_check_func
35 },
36 };
37
thead_errata_probe(unsigned int stage,unsigned long archid,unsigned long impid)38 static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid)
39 {
40 const struct errata_info *info;
41 u32 cpu_req_errata = 0;
42 int idx;
43
44 for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) {
45 info = &errata_list[idx];
46
47 if ((stage == RISCV_ALTERNATIVES_MODULE ||
48 info->stage == stage) && info->check_func(archid, impid))
49 cpu_req_errata |= (1U << idx);
50 }
51
52 return cpu_req_errata;
53 }
54
thead_errata_patch_func(struct alt_entry * begin,struct alt_entry * end,unsigned long archid,unsigned long impid,unsigned int stage)55 void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
56 unsigned long archid, unsigned long impid,
57 unsigned int stage)
58 {
59 struct alt_entry *alt;
60 u32 cpu_req_errata = thead_errata_probe(stage, archid, impid);
61 u32 tmp;
62
63 for (alt = begin; alt < end; alt++) {
64 if (alt->vendor_id != THEAD_VENDOR_ID)
65 continue;
66 if (alt->errata_id >= ERRATA_THEAD_NUMBER)
67 continue;
68
69 tmp = (1U << alt->errata_id);
70 if (cpu_req_errata & tmp) {
71 /* On vm-alternatives, the mmu isn't running yet */
72 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
73 memcpy((void *)__pa_symbol(alt->old_ptr),
74 (void *)__pa_symbol(alt->alt_ptr), alt->alt_len);
75 else
76 patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
77 }
78 }
79
80 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
81 local_flush_icache_all();
82 }
83