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 /* 39 * use memcpy() instead of *t = *s so that GCC replaces it 40 * by __memcpy() when KASAN is active 41 */ 42 memcpy(t, s, sizeof(*t)); 43 44 *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; 45 } 46 47 static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, 48 struct cpu_spec *s) 49 { 50 struct cpu_spec *t = &the_cpu_spec; 51 struct cpu_spec old; 52 53 t = PTRRELOC(t); 54 old = *t; 55 56 /* 57 * Copy everything, then do fixups. Use memcpy() instead of *t = *s 58 * so that GCC replaces it by __memcpy() when KASAN is active 59 */ 60 memcpy(t, s, sizeof(*t)); 61 62 /* 63 * If we are overriding a previous value derived from the real 64 * PVR with a new value obtained using a logical PVR value, 65 * don't modify the performance monitor fields. 66 */ 67 if (old.num_pmcs && !s->num_pmcs) { 68 t->num_pmcs = old.num_pmcs; 69 t->pmc_type = old.pmc_type; 70 71 /* 72 * Let's ensure that the 73 * fix for the PMAO bug is enabled on compatibility mode. 74 */ 75 t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG; 76 } 77 78 /* Set kuap ON at startup, will be disabled later if cmdline has 'nosmap' */ 79 if (IS_ENABLED(CONFIG_PPC_KUAP) && IS_ENABLED(CONFIG_PPC32)) 80 t->mmu_features |= MMU_FTR_KUAP; 81 82 *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; 83 84 /* 85 * Set the base platform string once; assumes 86 * we're called with real pvr first. 87 */ 88 if (*PTRRELOC(&powerpc_base_platform) == NULL) 89 *PTRRELOC(&powerpc_base_platform) = t->platform; 90 91 #if defined(CONFIG_PPC64) || defined(CONFIG_BOOKE) 92 /* ppc64 and booke expect identify_cpu to also call setup_cpu for 93 * that processor. I will consolidate that at a later time, for now, 94 * just use #ifdef. We also don't need to PTRRELOC the function 95 * pointer on ppc64 and booke as we are running at 0 in real mode 96 * on ppc64 and reloc_offset is always 0 on booke. 97 */ 98 if (t->cpu_setup) { 99 t->cpu_setup(offset, t); 100 } 101 #endif /* CONFIG_PPC64 || CONFIG_BOOKE */ 102 103 return t; 104 } 105 106 struct cpu_spec * __init identify_cpu(unsigned long offset, unsigned int pvr) 107 { 108 struct cpu_spec *s = cpu_specs; 109 int i; 110 111 BUILD_BUG_ON(!ARRAY_SIZE(cpu_specs)); 112 113 s = PTRRELOC(s); 114 115 for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++) { 116 if ((pvr & s->pvr_mask) == s->pvr_value) 117 return setup_cpu_spec(offset, s); 118 } 119 120 BUG(); 121 122 return NULL; 123 } 124 125 /* 126 * Used by cpufeatures to get the name for CPUs with a PVR table. 127 * If they don't hae a PVR table, cpufeatures gets the name from 128 * cpu device-tree node. 129 */ 130 void __init identify_cpu_name(unsigned int pvr) 131 { 132 struct cpu_spec *s = cpu_specs; 133 struct cpu_spec *t = &the_cpu_spec; 134 int i; 135 136 s = PTRRELOC(s); 137 t = PTRRELOC(t); 138 139 for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++) { 140 if ((pvr & s->pvr_mask) == s->pvr_value) { 141 t->cpu_name = s->cpu_name; 142 return; 143 } 144 } 145 } 146 147 148 #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS 149 struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS] = { 150 [0 ... NUM_CPU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT 151 }; 152 EXPORT_SYMBOL_GPL(cpu_feature_keys); 153 154 void __init cpu_feature_keys_init(void) 155 { 156 int i; 157 158 for (i = 0; i < NUM_CPU_FTR_KEYS; i++) { 159 unsigned long f = 1ul << i; 160 161 if (!(cur_cpu_spec->cpu_features & f)) 162 static_branch_disable(&cpu_feature_keys[i]); 163 } 164 } 165 166 struct static_key_true mmu_feature_keys[NUM_MMU_FTR_KEYS] = { 167 [0 ... NUM_MMU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT 168 }; 169 EXPORT_SYMBOL(mmu_feature_keys); 170 171 void __init mmu_feature_keys_init(void) 172 { 173 int i; 174 175 for (i = 0; i < NUM_MMU_FTR_KEYS; i++) { 176 unsigned long f = 1ul << i; 177 178 if (!(cur_cpu_spec->mmu_features & f)) 179 static_branch_disable(&mmu_feature_keys[i]); 180 } 181 } 182 #endif 183