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
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