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 static bool errata_probe_pbmt(unsigned int stage, 18 unsigned long arch_id, unsigned long impid) 19 { 20 if (!IS_ENABLED(CONFIG_ERRATA_THEAD_PBMT)) 21 return false; 22 23 if (arch_id != 0 || impid != 0) 24 return false; 25 26 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT || 27 stage == RISCV_ALTERNATIVES_MODULE) 28 return true; 29 30 return false; 31 } 32 33 static bool errata_probe_cmo(unsigned int stage, 34 unsigned long arch_id, unsigned long impid) 35 { 36 if (!IS_ENABLED(CONFIG_ERRATA_THEAD_CMO)) 37 return false; 38 39 if (arch_id != 0 || impid != 0) 40 return false; 41 42 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 43 return false; 44 45 riscv_cbom_block_size = L1_CACHE_BYTES; 46 riscv_noncoherent_supported(); 47 return true; 48 } 49 50 static u32 thead_errata_probe(unsigned int stage, 51 unsigned long archid, unsigned long impid) 52 { 53 u32 cpu_req_errata = 0; 54 55 if (errata_probe_pbmt(stage, archid, impid)) 56 cpu_req_errata |= BIT(ERRATA_THEAD_PBMT); 57 58 if (errata_probe_cmo(stage, archid, impid)) 59 cpu_req_errata |= BIT(ERRATA_THEAD_CMO); 60 61 return cpu_req_errata; 62 } 63 64 void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, 65 unsigned long archid, unsigned long impid, 66 unsigned int stage) 67 { 68 struct alt_entry *alt; 69 u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); 70 u32 tmp; 71 72 for (alt = begin; alt < end; alt++) { 73 if (alt->vendor_id != THEAD_VENDOR_ID) 74 continue; 75 if (alt->errata_id >= ERRATA_THEAD_NUMBER) 76 continue; 77 78 tmp = (1U << alt->errata_id); 79 if (cpu_req_errata & tmp) { 80 /* On vm-alternatives, the mmu isn't running yet */ 81 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 82 memcpy((void *)__pa_symbol(alt->old_ptr), 83 (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); 84 else 85 patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); 86 } 87 } 88 89 if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) 90 local_flush_icache_all(); 91 } 92