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
23static struct cpu_spec the_cpu_spec __ro_after_init;
24
25struct cpu_spec *cur_cpu_spec __ro_after_init = NULL;
26EXPORT_SYMBOL(cur_cpu_spec);
27
28/* The platform string corresponding to the real PVR */
29const char *powerpc_base_platform;
30
31#include "cpu_specs.h"
32
33void __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
47static 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
106struct 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 */
130void __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
149struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS] = {
150			[0 ... NUM_CPU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT
151};
152EXPORT_SYMBOL_GPL(cpu_feature_keys);
153
154void __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
166struct static_key_true mmu_feature_keys[NUM_MMU_FTR_KEYS] = {
167			[0 ... NUM_MMU_FTR_KEYS - 1] = STATIC_KEY_TRUE_INIT
168};
169EXPORT_SYMBOL(mmu_feature_keys);
170
171void __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