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
16struct errata_info_t {
17	char name[32];
18	bool (*check_func)(unsigned long  arch_id, unsigned long impid);
19};
20
21static 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
34static 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
48static 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
59static 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
72static 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
85void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
86			      unsigned long archid, unsigned long impid,
87			      unsigned int stage)
88{
89	struct alt_entry *alt;
90	u32 cpu_req_errata;
91	u32 cpu_apply_errata = 0;
92	u32 tmp;
93
94	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
95		return;
96
97	cpu_req_errata = sifive_errata_probe(archid, impid);
98
99	for (alt = begin; alt < end; alt++) {
100		if (alt->vendor_id != SIFIVE_VENDOR_ID)
101			continue;
102		if (alt->patch_id >= ERRATA_SIFIVE_NUMBER) {
103			WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id);
104			continue;
105		}
106
107		tmp = (1U << alt->patch_id);
108		if (cpu_req_errata & tmp) {
109			mutex_lock(&text_mutex);
110			patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
111					  alt->alt_len);
112			mutex_unlock(&text_mutex);
113			cpu_apply_errata |= tmp;
114		}
115	}
116	if (stage != RISCV_ALTERNATIVES_MODULE &&
117	    cpu_apply_errata != cpu_req_errata)
118		warn_miss_errata(cpu_req_errata - cpu_apply_errata);
119}
120