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 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 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 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 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 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