1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org) 4 * 5 * Modifications for ppc64: 6 * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com> 7 */ 8 9 #include <linux/string.h> 10 #include <linux/sched.h> 11 #include <linux/threads.h> 12 #include <linux/init.h> 13 #include <linux/export.h> 14 #include <linux/jump_label.h> 15 #include <linux/of.h> 16 17 #include <asm/cputable.h> 18 #include <asm/mce.h> 19 #include <asm/mmu.h> 20 #include <asm/setup.h> 21 #include <asm/cpu_setup.h> 22 23 static struct cpu_spec the_cpu_spec __ro_after_init; 24 25 struct cpu_spec *cur_cpu_spec __ro_after_init = NULL; 26 EXPORT_SYMBOL(cur_cpu_spec); 27 28 /* The platform string corresponding to the real PVR */ 29 const char *powerpc_base_platform; 30 31 #include "cpu_specs.h" 32 33 void __init set_cur_cpu_spec(struct cpu_spec *s) 34 { 35 struct cpu_spec *t = &the_cpu_spec; 36 37 t = PTRRELOC(t); 38 *t = *s; 39 *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; 40 } 41 42 static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, 43 struct cpu_spec *s) 44 { 45 struct cpu_spec *t = &the_cpu_spec; 46 struct cpu_spec old; 47 48 t = PTRRELOC(t); 49 old = *t; 50 51 /* Copy everything, then do fixups. */ 52 *t = *s; 53 54 /* 55 * If we are overriding a previous value derived from the real 56 * PVR with a new value obtained using a logical PVR value, 57 * don't modify the performance monitor fields. 58 */ 59 if (old.num_pmcs && !s->num_pmcs) { 60 t->num_pmcs = old.num_pmcs; 61 t->pmc_type = old.pmc_type; 62 63 /* 64 * Let's ensure that the 65 * fix for the PMAO bug is enabled on compatibility mode. 66 */ 67 t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG; 68 } 69 70 /* Set kuap ON at startup, will be disabled later if cmdline has 'nosmap' */ 71 if (IS_ENABLED(CONFIG_PPC_KUAP) && IS_ENABLED(CONFIG_PPC32)) 72 t->mmu_features |= MMU_FTR_KUAP; 73 74 *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; 75 76 /* 77 * Set the base platform string once; assumes 78 * we're called with real pvr first. 79 */ 80 if (*PTRRELOC(&powerpc_base_platform) == NULL) 81 *PTRRELOC(&powerpc_base_platform) = t->platform; 82 83 #if defined(CONFIG_PPC64) || defined(CONFIG_BOOKE) 84 /* ppc64 and booke expect identify_cpu to also call setup_cpu for 85 * that processor. I will consolidate that at a later time, for now, 86 * just use #ifdef. We also don't need to PTRRELOC the function 87 * pointer on ppc64 and booke as we are running at 0 in real mode 88 * on ppc64 and reloc_offset is always 0 on booke. 89 */ 90 if (t->cpu_setup) { 91 t->cpu_setup(offset, t); 92 } 93 #endif /* CONFIG_PPC64 || CONFIG_BOOKE */ 94 95 return t; 96 } 97 98 struct cpu_spec * __init identify_cpu(unsigned long offset, unsigned int pvr) 99 { 100 struct cpu_spec *s = cpu_specs; 101 int i; 102 103 BUILD_BUG_ON(!ARRAY_SIZE(cpu_specs)); 104 105 s = PTRRELOC(s); 106 107 for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++) { 108 if ((pvr & s->pvr_mask) == s->pvr_value) 109 return setup_cpu_spec(offset, s); 110 } 111 112 BUG(); 113 114 return NULL; 115 } 116 117 /* 118 * Used by cpufeatures to get the name for CPUs with a PVR table. 119 * If they don't hae a PVR table, cpufeatures gets the name from 120 * cpu device-tree node. 121 */ 122 void __init identify_cpu_name(unsigned int pvr) 123 { 124 struct cpu_spec *s = cpu_specs; 125 struct cpu_spec *t = &the_cpu_spec; 126 int i; 127 128 s = PTRRELOC(s); 129 t = PTRRELOC(t); 130 131 for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++) { 132 if ((pvr & s->pvr_mask) == s->pvr_value) { 133 t->cpu_name = s->cpu_name; 134 return; 135 } 136 } 137 } 138 139 140 #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS 141 struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS] = { 142 [0 ... NUM_CPU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT 143 }; 144 EXPORT_SYMBOL_GPL(cpu_feature_keys); 145 146 void __init cpu_feature_keys_init(void) 147 { 148 int i; 149 150 for (i = 0; i < NUM_CPU_FTR_KEYS; i++) { 151 unsigned long f = 1ul << i; 152 153 if (!(cur_cpu_spec->cpu_features & f)) 154 static_branch_disable(&cpu_feature_keys[i]); 155 } 156 } 157 158 struct static_key_true mmu_feature_keys[NUM_MMU_FTR_KEYS] = { 159 [0 ... NUM_MMU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT 160 }; 161 EXPORT_SYMBOL(mmu_feature_keys); 162 163 void __init mmu_feature_keys_init(void) 164 { 165 int i; 166 167 for (i = 0; i < NUM_MMU_FTR_KEYS; i++) { 168 unsigned long f = 1ul << i; 169 170 if (!(cur_cpu_spec->mmu_features & f)) 171 static_branch_disable(&mmu_feature_keys[i]); 172 } 173 } 174 #endif 175