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[32]; 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 46 #ifdef CONFIG_MMU 47 tlb_flush_all_threshold = 0; 48 #endif 49 50 return true; 51 } 52 53 static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = { 54 { 55 .name = "cip-453", 56 .check_func = errata_cip_453_check_func 57 }, 58 { 59 .name = "cip-1200", 60 .check_func = errata_cip_1200_check_func 61 }, 62 }; 63 64 static u32 __init_or_module sifive_errata_probe(unsigned long archid, 65 unsigned long impid) 66 { 67 int idx; 68 u32 cpu_req_errata = 0; 69 70 for (idx = 0; idx < ERRATA_SIFIVE_NUMBER; idx++) 71 if (errata_list[idx].check_func(archid, impid)) 72 cpu_req_errata |= (1U << idx); 73 74 return cpu_req_errata; 75 } 76 77 static void __init_or_module warn_miss_errata(u32 miss_errata) 78 { 79 int i; 80 81 pr_warn("----------------------------------------------------------------\n"); 82 pr_warn("WARNING: Missing the following errata may cause potential issues\n"); 83 for (i = 0; i < ERRATA_SIFIVE_NUMBER; i++) 84 if (miss_errata & 0x1 << i) 85 pr_warn("\tSiFive Errata[%d]:%s\n", i, errata_list[i].name); 86 pr_warn("Please enable the corresponding Kconfig to apply them\n"); 87 pr_warn("----------------------------------------------------------------\n"); 88 } 89 90 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, 91 unsigned long archid, unsigned long impid, 92 unsigned int stage) 93 { 94 struct alt_entry *alt; 95 u32 cpu_req_errata; 96 u32 cpu_apply_errata = 0; 97 u32 tmp; 98 99 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 100 return; 101 102 cpu_req_errata = sifive_errata_probe(archid, impid); 103 104 for (alt = begin; alt < end; alt++) { 105 if (alt->vendor_id != SIFIVE_VENDOR_ID) 106 continue; 107 if (alt->patch_id >= ERRATA_SIFIVE_NUMBER) { 108 WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id); 109 continue; 110 } 111 112 tmp = (1U << alt->patch_id); 113 if (cpu_req_errata & tmp) { 114 mutex_lock(&text_mutex); 115 patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt), 116 alt->alt_len); 117 mutex_unlock(&text_mutex); 118 cpu_apply_errata |= tmp; 119 } 120 } 121 if (stage != RISCV_ALTERNATIVES_MODULE && 122 cpu_apply_errata != cpu_req_errata) 123 warn_miss_errata(cpu_req_errata - cpu_apply_errata); 124 } 125