arch/powerpc/kernel/cputable.c

   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 __read_mostly;
  24
  25 struct cpu_spec* cur_cpu_spec __read_mostly = 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