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/memory.h> 9 #include <linux/module.h> 10 #include <linux/string.h> 11 #include <linux/uaccess.h> 12 #include <asm/alternative.h> 13 #include <asm/cacheflush.h> 14 #include <asm/errata_list.h> 15 #include <asm/patch.h> 16 #include <asm/vendorid_list.h> 17 18 static bool errata_probe_pbmt(unsigned int stage, 19 unsigned long arch_id, unsigned long impid) 20 { 21 if (!IS_ENABLED(CONFIG_ERRATA_THEAD_PBMT)) 22 return false; 23 24 if (arch_id != 0 || impid != 0) 25 return false; 26 27 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT || 28 stage == RISCV_ALTERNATIVES_MODULE) 29 return true; 30 31 return false; 32 } 33 34 static bool errata_probe_cmo(unsigned int stage, 35 unsigned long arch_id, unsigned long impid) 36 { 37 if (!IS_ENABLED(CONFIG_ERRATA_THEAD_CMO)) 38 return false; 39 40 if (arch_id != 0 || impid != 0) 41 return false; 42 43 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 44 return false; 45 46 riscv_cbom_block_size = L1_CACHE_BYTES; 47 riscv_noncoherent_supported(); 48 return true; 49 } 50 51 static bool errata_probe_pmu(unsigned int stage, 52 unsigned long arch_id, unsigned long impid) 53 { 54 if (!IS_ENABLED(CONFIG_ERRATA_THEAD_PMU)) 55 return false; 56 57 /* target-c9xx cores report arch_id and impid as 0 */ 58 if (arch_id != 0 || impid != 0) 59 return false; 60 61 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 62 return false; 63 64 return true; 65 } 66 67 static u32 thead_errata_probe(unsigned int stage, 68 unsigned long archid, unsigned long impid) 69 { 70 u32 cpu_req_errata = 0; 71 72 if (errata_probe_pbmt(stage, archid, impid)) 73 cpu_req_errata |= BIT(ERRATA_THEAD_PBMT); 74 75 if (errata_probe_cmo(stage, archid, impid)) 76 cpu_req_errata |= BIT(ERRATA_THEAD_CMO); 77 78 if (errata_probe_pmu(stage, archid, impid)) 79 cpu_req_errata |= BIT(ERRATA_THEAD_PMU); 80 81 return cpu_req_errata; 82 } 83 84 void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, 85 unsigned long archid, unsigned long impid, 86 unsigned int stage) 87 { 88 struct alt_entry *alt; 89 u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); 90 u32 tmp; 91 void *oldptr, *altptr; 92 93 for (alt = begin; alt < end; alt++) { 94 if (alt->vendor_id != THEAD_VENDOR_ID) 95 continue; 96 if (alt->errata_id >= ERRATA_THEAD_NUMBER) 97 continue; 98 99 tmp = (1U << alt->errata_id); 100 if (cpu_req_errata & tmp) { 101 oldptr = ALT_OLD_PTR(alt); 102 altptr = ALT_ALT_PTR(alt); 103 104 /* On vm-alternatives, the mmu isn't running yet */ 105 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) { 106 memcpy(oldptr, altptr, alt->alt_len); 107 } else { 108 mutex_lock(&text_mutex); 109 patch_text_nosync(oldptr, altptr, alt->alt_len); 110 mutex_unlock(&text_mutex); 111 } 112 } 113 } 114 115 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 116 local_flush_icache_all(); 117 } 118