xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision ac3cb6de)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Contains CPU feature definitions
4  *
5  * Copyright (C) 2015 ARM Ltd.
6  *
7  * A note for the weary kernel hacker: the code here is confusing and hard to
8  * follow! That's partly because it's solving a nasty problem, but also because
9  * there's a little bit of over-abstraction that tends to obscure what's going
10  * on behind a maze of helper functions and macros.
11  *
12  * The basic problem is that hardware folks have started gluing together CPUs
13  * with distinct architectural features; in some cases even creating SoCs where
14  * user-visible instructions are available only on a subset of the available
15  * cores. We try to address this by snapshotting the feature registers of the
16  * boot CPU and comparing these with the feature registers of each secondary
17  * CPU when bringing them up. If there is a mismatch, then we update the
18  * snapshot state to indicate the lowest-common denominator of the feature,
19  * known as the "safe" value. This snapshot state can be queried to view the
20  * "sanitised" value of a feature register.
21  *
22  * The sanitised register values are used to decide which capabilities we
23  * have in the system. These may be in the form of traditional "hwcaps"
24  * advertised to userspace or internal "cpucaps" which are used to configure
25  * things like alternative patching and static keys. While a feature mismatch
26  * may result in a TAINT_CPU_OUT_OF_SPEC kernel taint, a capability mismatch
27  * may prevent a CPU from being onlined at all.
28  *
29  * Some implementation details worth remembering:
30  *
31  * - Mismatched features are *always* sanitised to a "safe" value, which
32  *   usually indicates that the feature is not supported.
33  *
34  * - A mismatched feature marked with FTR_STRICT will cause a "SANITY CHECK"
35  *   warning when onlining an offending CPU and the kernel will be tainted
36  *   with TAINT_CPU_OUT_OF_SPEC.
37  *
38  * - Features marked as FTR_VISIBLE have their sanitised value visible to
39  *   userspace. FTR_VISIBLE features in registers that are only visible
40  *   to EL0 by trapping *must* have a corresponding HWCAP so that late
41  *   onlining of CPUs cannot lead to features disappearing at runtime.
42  *
43  * - A "feature" is typically a 4-bit register field. A "capability" is the
44  *   high-level description derived from the sanitised field value.
45  *
46  * - Read the Arm ARM (DDI 0487F.a) section D13.1.3 ("Principles of the ID
47  *   scheme for fields in ID registers") to understand when feature fields
48  *   may be signed or unsigned (FTR_SIGNED and FTR_UNSIGNED accordingly).
49  *
50  * - KVM exposes its own view of the feature registers to guest operating
51  *   systems regardless of FTR_VISIBLE. This is typically driven from the
52  *   sanitised register values to allow virtual CPUs to be migrated between
53  *   arbitrary physical CPUs, but some features not present on the host are
54  *   also advertised and emulated. Look at sys_reg_descs[] for the gory
55  *   details.
56  *
57  * - If the arm64_ftr_bits[] for a register has a missing field, then this
58  *   field is treated as STRICT RES0, including for read_sanitised_ftr_reg().
59  *   This is stronger than FTR_HIDDEN and can be used to hide features from
60  *   KVM guests.
61  */
62 
63 #define pr_fmt(fmt) "CPU features: " fmt
64 
65 #include <linux/bsearch.h>
66 #include <linux/cpumask.h>
67 #include <linux/crash_dump.h>
68 #include <linux/kstrtox.h>
69 #include <linux/sort.h>
70 #include <linux/stop_machine.h>
71 #include <linux/sysfs.h>
72 #include <linux/types.h>
73 #include <linux/minmax.h>
74 #include <linux/mm.h>
75 #include <linux/cpu.h>
76 #include <linux/kasan.h>
77 #include <linux/percpu.h>
78 
79 #include <asm/cpu.h>
80 #include <asm/cpufeature.h>
81 #include <asm/cpu_ops.h>
82 #include <asm/fpsimd.h>
83 #include <asm/hwcap.h>
84 #include <asm/insn.h>
85 #include <asm/kvm_host.h>
86 #include <asm/mmu_context.h>
87 #include <asm/mte.h>
88 #include <asm/processor.h>
89 #include <asm/smp.h>
90 #include <asm/sysreg.h>
91 #include <asm/traps.h>
92 #include <asm/vectors.h>
93 #include <asm/virt.h>
94 
95 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
96 static DECLARE_BITMAP(elf_hwcap, MAX_CPU_FEATURES) __read_mostly;
97 
98 #ifdef CONFIG_COMPAT
99 #define COMPAT_ELF_HWCAP_DEFAULT	\
100 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
101 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
102 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\
103 				 COMPAT_HWCAP_LPAE)
104 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
105 unsigned int compat_elf_hwcap2 __read_mostly;
106 #endif
107 
108 DECLARE_BITMAP(system_cpucaps, ARM64_NCAPS);
109 EXPORT_SYMBOL(system_cpucaps);
110 static struct arm64_cpu_capabilities const __ro_after_init *cpucap_ptrs[ARM64_NCAPS];
111 
112 DECLARE_BITMAP(boot_cpucaps, ARM64_NCAPS);
113 
114 bool arm64_use_ng_mappings = false;
115 EXPORT_SYMBOL(arm64_use_ng_mappings);
116 
117 DEFINE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector) = vectors;
118 
119 /*
120  * Permit PER_LINUX32 and execve() of 32-bit binaries even if not all CPUs
121  * support it?
122  */
123 static bool __read_mostly allow_mismatched_32bit_el0;
124 
125 /*
126  * Static branch enabled only if allow_mismatched_32bit_el0 is set and we have
127  * seen at least one CPU capable of 32-bit EL0.
128  */
129 DEFINE_STATIC_KEY_FALSE(arm64_mismatched_32bit_el0);
130 
131 /*
132  * Mask of CPUs supporting 32-bit EL0.
133  * Only valid if arm64_mismatched_32bit_el0 is enabled.
134  */
135 static cpumask_var_t cpu_32bit_el0_mask __cpumask_var_read_mostly;
136 
137 void dump_cpu_features(void)
138 {
139 	/* file-wide pr_fmt adds "CPU features: " prefix */
140 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &system_cpucaps);
141 }
142 
143 #define ARM64_CPUID_FIELDS(reg, field, min_value)			\
144 		.sys_reg = SYS_##reg,							\
145 		.field_pos = reg##_##field##_SHIFT,						\
146 		.field_width = reg##_##field##_WIDTH,						\
147 		.sign = reg##_##field##_SIGNED,							\
148 		.min_field_value = reg##_##field##_##min_value,
149 
150 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
151 	{						\
152 		.sign = SIGNED,				\
153 		.visible = VISIBLE,			\
154 		.strict = STRICT,			\
155 		.type = TYPE,				\
156 		.shift = SHIFT,				\
157 		.width = WIDTH,				\
158 		.safe_val = SAFE_VAL,			\
159 	}
160 
161 /* Define a feature with unsigned values */
162 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
163 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
164 
165 /* Define a feature with a signed value */
166 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
167 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
168 
169 #define ARM64_FTR_END					\
170 	{						\
171 		.width = 0,				\
172 	}
173 
174 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
175 
176 static bool __system_matches_cap(unsigned int n);
177 
178 /*
179  * NOTE: Any changes to the visibility of features should be kept in
180  * sync with the documentation of the CPU feature register ABI.
181  */
182 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
183 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_RNDR_SHIFT, 4, 0),
184 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_TLB_SHIFT, 4, 0),
185 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_TS_SHIFT, 4, 0),
186 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_FHM_SHIFT, 4, 0),
187 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_DP_SHIFT, 4, 0),
188 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SM4_SHIFT, 4, 0),
189 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SM3_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA3_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_RDM_SHIFT, 4, 0),
192 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_ATOMIC_SHIFT, 4, 0),
193 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_CRC32_SHIFT, 4, 0),
194 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA2_SHIFT, 4, 0),
195 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA1_SHIFT, 4, 0),
196 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_AES_SHIFT, 4, 0),
197 	ARM64_FTR_END,
198 };
199 
200 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
201 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_I8MM_SHIFT, 4, 0),
202 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_DGH_SHIFT, 4, 0),
203 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_BF16_SHIFT, 4, 0),
204 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_SPECRES_SHIFT, 4, 0),
205 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_SB_SHIFT, 4, 0),
206 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_FRINTTS_SHIFT, 4, 0),
207 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
208 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_GPI_SHIFT, 4, 0),
209 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
210 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_GPA_SHIFT, 4, 0),
211 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_LRCPC_SHIFT, 4, 0),
212 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_FCMA_SHIFT, 4, 0),
213 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_JSCVT_SHIFT, 4, 0),
214 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
215 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_EL1_API_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
217 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_EL1_APA_SHIFT, 4, 0),
218 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_EL1_DPB_SHIFT, 4, 0),
219 	ARM64_FTR_END,
220 };
221 
222 static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
223 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0),
224 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0),
225 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0),
226 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_MOPS_SHIFT, 4, 0),
227 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
228 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_EL1_APA3_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
230 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_GPA3_SHIFT, 4, 0),
231 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRES_SHIFT, 4, 0),
232 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_WFxT_SHIFT, 4, 0),
233 	ARM64_FTR_END,
234 };
235 
236 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
237 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV3_SHIFT, 4, 0),
238 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV2_SHIFT, 4, 0),
239 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_DIT_SHIFT, 4, 0),
240 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_AMU_SHIFT, 4, 0),
241 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_MPAM_SHIFT, 4, 0),
242 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SEL2_SHIFT, 4, 0),
243 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
244 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SVE_SHIFT, 4, 0),
245 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_RAS_SHIFT, 4, 0),
246 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_GIC_SHIFT, 4, 0),
247 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_AdvSIMD_SHIFT, 4, ID_AA64PFR0_EL1_AdvSIMD_NI),
248 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_FP_SHIFT, 4, ID_AA64PFR0_EL1_FP_NI),
249 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_EL3_SHIFT, 4, 0),
250 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_EL2_SHIFT, 4, 0),
251 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_EL1_SHIFT, 4, ID_AA64PFR0_EL1_ELx_64BIT_ONLY),
252 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_EL0_SHIFT, 4, ID_AA64PFR0_EL1_ELx_64BIT_ONLY),
253 	ARM64_FTR_END,
254 };
255 
256 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
257 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
258 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SME_SHIFT, 4, 0),
259 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MPAM_frac_SHIFT, 4, 0),
260 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_RAS_frac_SHIFT, 4, 0),
261 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
262 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MTE_SHIFT, 4, ID_AA64PFR1_EL1_MTE_NI),
263 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SSBS_SHIFT, 4, ID_AA64PFR1_EL1_SSBS_NI),
264 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
265 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_BT_SHIFT, 4, 0),
266 	ARM64_FTR_END,
267 };
268 
269 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
270 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
271 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_F64MM_SHIFT, 4, 0),
272 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
273 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_F32MM_SHIFT, 4, 0),
274 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
275 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_I8MM_SHIFT, 4, 0),
276 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
277 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_SM4_SHIFT, 4, 0),
278 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
279 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_SHA3_SHIFT, 4, 0),
280 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
281 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_BF16_SHIFT, 4, 0),
282 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
283 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_BitPerm_SHIFT, 4, 0),
284 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
285 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_AES_SHIFT, 4, 0),
286 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
287 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_EL1_SVEver_SHIFT, 4, 0),
288 	ARM64_FTR_END,
289 };
290 
291 static const struct arm64_ftr_bits ftr_id_aa64smfr0[] = {
292 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
293 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_FA64_SHIFT, 1, 0),
294 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
295 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_SMEver_SHIFT, 4, 0),
296 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
297 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_I16I64_SHIFT, 4, 0),
298 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
299 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_F64F64_SHIFT, 1, 0),
300 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
301 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_I16I32_SHIFT, 4, 0),
302 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
303 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_B16B16_SHIFT, 1, 0),
304 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
305 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_F16F16_SHIFT, 1, 0),
306 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
307 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_I8I32_SHIFT, 4, 0),
308 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
309 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_F16F32_SHIFT, 1, 0),
310 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
311 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_B16F32_SHIFT, 1, 0),
312 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
313 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_BI32I32_SHIFT, 1, 0),
314 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
315 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_F32F32_SHIFT, 1, 0),
316 	ARM64_FTR_END,
317 };
318 
319 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
320 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_ECV_SHIFT, 4, 0),
321 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_FGT_SHIFT, 4, 0),
322 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_EXS_SHIFT, 4, 0),
323 	/*
324 	 * Page size not being supported at Stage-2 is not fatal. You
325 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
326 	 * your favourite nesting hypervisor.
327 	 *
328 	 * There is a small corner case where the hypervisor explicitly
329 	 * advertises a given granule size at Stage-2 (value 2) on some
330 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
331 	 * vCPUs. Although this is not forbidden by the architecture, it
332 	 * indicates that the hypervisor is being silly (or buggy).
333 	 *
334 	 * We make no effort to cope with this and pretend that if these
335 	 * fields are inconsistent across vCPUs, then it isn't worth
336 	 * trying to bring KVM up.
337 	 */
338 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_EL1_TGRAN4_2_SHIFT, 4, 1),
339 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_EL1_TGRAN64_2_SHIFT, 4, 1),
340 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_EL1_TGRAN16_2_SHIFT, 4, 1),
341 	/*
342 	 * We already refuse to boot CPUs that don't support our configured
343 	 * page size, so we can only detect mismatches for a page size other
344 	 * than the one we're currently using. Unfortunately, SoCs like this
345 	 * exist in the wild so, even though we don't like it, we'll have to go
346 	 * along with it and treat them as non-strict.
347 	 */
348 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_TGRAN4_SHIFT, 4, ID_AA64MMFR0_EL1_TGRAN4_NI),
349 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_TGRAN64_SHIFT, 4, ID_AA64MMFR0_EL1_TGRAN64_NI),
350 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_TGRAN16_SHIFT, 4, ID_AA64MMFR0_EL1_TGRAN16_NI),
351 
352 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_BIGENDEL0_SHIFT, 4, 0),
353 	/* Linux shouldn't care about secure memory */
354 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_SNSMEM_SHIFT, 4, 0),
355 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_BIGEND_SHIFT, 4, 0),
356 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_ASIDBITS_SHIFT, 4, 0),
357 	/*
358 	 * Differing PARange is fine as long as all peripherals and memory are mapped
359 	 * within the minimum PARange of all CPUs
360 	 */
361 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EL1_PARANGE_SHIFT, 4, 0),
362 	ARM64_FTR_END,
363 };
364 
365 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TIDCP1_SHIFT, 4, 0),
367 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, 0),
368 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HCX_SHIFT, 4, 0),
369 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_ETS_SHIFT, 4, 0),
370 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TWED_SHIFT, 4, 0),
371 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_XNX_SHIFT, 4, 0),
372 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64MMFR1_EL1_SpecSEI_SHIFT, 4, 0),
373 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_PAN_SHIFT, 4, 0),
374 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_LO_SHIFT, 4, 0),
375 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HPDS_SHIFT, 4, 0),
376 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_VH_SHIFT, 4, 0),
377 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_VMIDBits_SHIFT, 4, 0),
378 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HAFDBS_SHIFT, 4, 0),
379 	ARM64_FTR_END,
380 };
381 
382 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
383 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_E0PD_SHIFT, 4, 0),
384 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_EVT_SHIFT, 4, 0),
385 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_BBM_SHIFT, 4, 0),
386 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_TTL_SHIFT, 4, 0),
387 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_FWB_SHIFT, 4, 0),
388 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_IDS_SHIFT, 4, 0),
389 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_AT_SHIFT, 4, 0),
390 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_ST_SHIFT, 4, 0),
391 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_NV_SHIFT, 4, 0),
392 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_CCIDX_SHIFT, 4, 0),
393 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_VARange_SHIFT, 4, 0),
394 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_IESB_SHIFT, 4, 0),
395 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_LSM_SHIFT, 4, 0),
396 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_UAO_SHIFT, 4, 0),
397 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EL1_CnP_SHIFT, 4, 0),
398 	ARM64_FTR_END,
399 };
400 
401 static const struct arm64_ftr_bits ftr_id_aa64mmfr3[] = {
402 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR3_EL1_S1PIE_SHIFT, 4, 0),
403 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR3_EL1_TCRX_SHIFT, 4, 0),
404 	ARM64_FTR_END,
405 };
406 
407 static const struct arm64_ftr_bits ftr_ctr[] = {
408 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
409 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_EL0_DIC_SHIFT, 1, 1),
410 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_EL0_IDC_SHIFT, 1, 1),
411 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_EL0_CWG_SHIFT, 4, 0),
412 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_EL0_ERG_SHIFT, 4, 0),
413 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_EL0_DminLine_SHIFT, 4, 1),
414 	/*
415 	 * Linux can handle differing I-cache policies. Userspace JITs will
416 	 * make use of *minLine.
417 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
418 	 */
419 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, CTR_EL0_L1Ip_SHIFT, 2, CTR_EL0_L1Ip_VIPT),	/* L1Ip */
420 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_EL0_IminLine_SHIFT, 4, 0),
421 	ARM64_FTR_END,
422 };
423 
424 static struct arm64_ftr_override __ro_after_init no_override = { };
425 
426 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
427 	.name		= "SYS_CTR_EL0",
428 	.ftr_bits	= ftr_ctr,
429 	.override	= &no_override,
430 };
431 
432 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
433 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_InnerShr_SHIFT, 4, 0xf),
434 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_FCSE_SHIFT, 4, 0),
435 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_AuxReg_SHIFT, 4, 0),
436 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_TCM_SHIFT, 4, 0),
437 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_ShareLvl_SHIFT, 4, 0),
438 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_OuterShr_SHIFT, 4, 0xf),
439 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_PMSA_SHIFT, 4, 0),
440 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_EL1_VMSA_SHIFT, 4, 0),
441 	ARM64_FTR_END,
442 };
443 
444 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
445 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_DoubleLock_SHIFT, 4, 0),
446 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_PMSVer_SHIFT, 4, 0),
447 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_CTX_CMPs_SHIFT, 4, 0),
448 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_WRPs_SHIFT, 4, 0),
449 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_BRPs_SHIFT, 4, 0),
450 	/*
451 	 * We can instantiate multiple PMU instances with different levels
452 	 * of support.
453 	 */
454 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_EL1_PMUVer_SHIFT, 4, 0),
455 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_EL1_DebugVer_SHIFT, 4, 0x6),
456 	ARM64_FTR_END,
457 };
458 
459 static const struct arm64_ftr_bits ftr_mvfr0[] = {
460 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPRound_SHIFT, 4, 0),
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPShVec_SHIFT, 4, 0),
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPSqrt_SHIFT, 4, 0),
463 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPDivide_SHIFT, 4, 0),
464 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPTrap_SHIFT, 4, 0),
465 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPDP_SHIFT, 4, 0),
466 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPSP_SHIFT, 4, 0),
467 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_SIMDReg_SHIFT, 4, 0),
468 	ARM64_FTR_END,
469 };
470 
471 static const struct arm64_ftr_bits ftr_mvfr1[] = {
472 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_SIMDFMAC_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_FPHP_SHIFT, 4, 0),
474 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_SIMDHP_SHIFT, 4, 0),
475 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_SIMDSP_SHIFT, 4, 0),
476 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_SIMDInt_SHIFT, 4, 0),
477 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_SIMDLS_SHIFT, 4, 0),
478 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_FPDNaN_SHIFT, 4, 0),
479 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR1_EL1_FPFtZ_SHIFT, 4, 0),
480 	ARM64_FTR_END,
481 };
482 
483 static const struct arm64_ftr_bits ftr_mvfr2[] = {
484 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_EL1_FPMisc_SHIFT, 4, 0),
485 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_EL1_SIMDMisc_SHIFT, 4, 0),
486 	ARM64_FTR_END,
487 };
488 
489 static const struct arm64_ftr_bits ftr_dczid[] = {
490 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_EL0_DZP_SHIFT, 1, 1),
491 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_EL0_BS_SHIFT, 4, 0),
492 	ARM64_FTR_END,
493 };
494 
495 static const struct arm64_ftr_bits ftr_gmid[] = {
496 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, GMID_EL1_BS_SHIFT, 4, 0),
497 	ARM64_FTR_END,
498 };
499 
500 static const struct arm64_ftr_bits ftr_id_isar0[] = {
501 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_Divide_SHIFT, 4, 0),
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_Debug_SHIFT, 4, 0),
503 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_Coproc_SHIFT, 4, 0),
504 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_CmpBranch_SHIFT, 4, 0),
505 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_BitField_SHIFT, 4, 0),
506 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_BitCount_SHIFT, 4, 0),
507 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_EL1_Swap_SHIFT, 4, 0),
508 	ARM64_FTR_END,
509 };
510 
511 static const struct arm64_ftr_bits ftr_id_isar5[] = {
512 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_RDM_SHIFT, 4, 0),
513 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_CRC32_SHIFT, 4, 0),
514 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_SHA2_SHIFT, 4, 0),
515 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_SHA1_SHIFT, 4, 0),
516 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_AES_SHIFT, 4, 0),
517 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_EL1_SEVL_SHIFT, 4, 0),
518 	ARM64_FTR_END,
519 };
520 
521 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
522 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_EVT_SHIFT, 4, 0),
523 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_CCIDX_SHIFT, 4, 0),
524 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_LSM_SHIFT, 4, 0),
525 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_HPDS_SHIFT, 4, 0),
526 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_CnP_SHIFT, 4, 0),
527 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_XNX_SHIFT, 4, 0),
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EL1_AC2_SHIFT, 4, 0),
529 
530 	/*
531 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
532 	 * external abort on speculative read. It is safe to assume that an
533 	 * SError might be generated than it will not be. Hence it has been
534 	 * classified as FTR_HIGHER_SAFE.
535 	 */
536 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_EL1_SpecSEI_SHIFT, 4, 0),
537 	ARM64_FTR_END,
538 };
539 
540 static const struct arm64_ftr_bits ftr_id_isar4[] = {
541 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_SWP_frac_SHIFT, 4, 0),
542 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_PSR_M_SHIFT, 4, 0),
543 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_SynchPrim_frac_SHIFT, 4, 0),
544 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_Barrier_SHIFT, 4, 0),
545 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_SMC_SHIFT, 4, 0),
546 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_Writeback_SHIFT, 4, 0),
547 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_WithShifts_SHIFT, 4, 0),
548 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_EL1_Unpriv_SHIFT, 4, 0),
549 	ARM64_FTR_END,
550 };
551 
552 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
553 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_EL1_ETS_SHIFT, 4, 0),
554 	ARM64_FTR_END,
555 };
556 
557 static const struct arm64_ftr_bits ftr_id_isar6[] = {
558 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_I8MM_SHIFT, 4, 0),
559 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_BF16_SHIFT, 4, 0),
560 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_SPECRES_SHIFT, 4, 0),
561 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_SB_SHIFT, 4, 0),
562 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_FHM_SHIFT, 4, 0),
563 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_DP_SHIFT, 4, 0),
564 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_EL1_JSCVT_SHIFT, 4, 0),
565 	ARM64_FTR_END,
566 };
567 
568 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
569 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_DIT_SHIFT, 4, 0),
570 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_CSV2_SHIFT, 4, 0),
571 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_State3_SHIFT, 4, 0),
572 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_State2_SHIFT, 4, 0),
573 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_State1_SHIFT, 4, 0),
574 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_EL1_State0_SHIFT, 4, 0),
575 	ARM64_FTR_END,
576 };
577 
578 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
579 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_GIC_SHIFT, 4, 0),
580 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_Virt_frac_SHIFT, 4, 0),
581 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_Sec_frac_SHIFT, 4, 0),
582 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_GenTimer_SHIFT, 4, 0),
583 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_Virtualization_SHIFT, 4, 0),
584 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_MProgMod_SHIFT, 4, 0),
585 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_Security_SHIFT, 4, 0),
586 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_EL1_ProgMod_SHIFT, 4, 0),
587 	ARM64_FTR_END,
588 };
589 
590 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
591 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_EL1_SSBS_SHIFT, 4, 0),
592 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_EL1_CSV3_SHIFT, 4, 0),
593 	ARM64_FTR_END,
594 };
595 
596 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
597 	/* [31:28] TraceFilt */
598 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_DFR0_EL1_PerfMon_SHIFT, 4, 0),
599 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_MProfDbg_SHIFT, 4, 0),
600 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_MMapTrc_SHIFT, 4, 0),
601 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_CopTrc_SHIFT, 4, 0),
602 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_MMapDbg_SHIFT, 4, 0),
603 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_CopSDbg_SHIFT, 4, 0),
604 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_EL1_CopDbg_SHIFT, 4, 0),
605 	ARM64_FTR_END,
606 };
607 
608 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
609 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_EL1_MTPMU_SHIFT, 4, 0),
610 	ARM64_FTR_END,
611 };
612 
613 static const struct arm64_ftr_bits ftr_zcr[] = {
614 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
615 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_WIDTH, 0),	/* LEN */
616 	ARM64_FTR_END,
617 };
618 
619 static const struct arm64_ftr_bits ftr_smcr[] = {
620 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
621 		SMCR_ELx_LEN_SHIFT, SMCR_ELx_LEN_WIDTH, 0),	/* LEN */
622 	ARM64_FTR_END,
623 };
624 
625 /*
626  * Common ftr bits for a 32bit register with all hidden, strict
627  * attributes, with 4bit feature fields and a default safe value of
628  * 0. Covers the following 32bit registers:
629  * id_isar[1-3], id_mmfr[1-3]
630  */
631 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
632 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
633 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
634 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
635 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
636 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
637 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
638 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
639 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
640 	ARM64_FTR_END,
641 };
642 
643 /* Table for a single 32bit feature value */
644 static const struct arm64_ftr_bits ftr_single32[] = {
645 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
646 	ARM64_FTR_END,
647 };
648 
649 static const struct arm64_ftr_bits ftr_raz[] = {
650 	ARM64_FTR_END,
651 };
652 
653 #define __ARM64_FTR_REG_OVERRIDE(id_str, id, table, ovr) {	\
654 		.sys_id = id,					\
655 		.reg = 	&(struct arm64_ftr_reg){		\
656 			.name = id_str,				\
657 			.override = (ovr),			\
658 			.ftr_bits = &((table)[0]),		\
659 	}}
660 
661 #define ARM64_FTR_REG_OVERRIDE(id, table, ovr)	\
662 	__ARM64_FTR_REG_OVERRIDE(#id, id, table, ovr)
663 
664 #define ARM64_FTR_REG(id, table)		\
665 	__ARM64_FTR_REG_OVERRIDE(#id, id, table, &no_override)
666 
667 struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override;
668 struct arm64_ftr_override __ro_after_init id_aa64pfr0_override;
669 struct arm64_ftr_override __ro_after_init id_aa64pfr1_override;
670 struct arm64_ftr_override __ro_after_init id_aa64zfr0_override;
671 struct arm64_ftr_override __ro_after_init id_aa64smfr0_override;
672 struct arm64_ftr_override __ro_after_init id_aa64isar1_override;
673 struct arm64_ftr_override __ro_after_init id_aa64isar2_override;
674 
675 struct arm64_ftr_override arm64_sw_feature_override;
676 
677 static const struct __ftr_reg_entry {
678 	u32			sys_id;
679 	struct arm64_ftr_reg 	*reg;
680 } arm64_ftr_regs[] = {
681 
682 	/* Op1 = 0, CRn = 0, CRm = 1 */
683 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
684 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
685 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
686 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
687 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
688 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
689 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
690 
691 	/* Op1 = 0, CRn = 0, CRm = 2 */
692 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
693 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
694 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
695 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
696 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
697 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
698 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
699 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
700 
701 	/* Op1 = 0, CRn = 0, CRm = 3 */
702 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_mvfr0),
703 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_mvfr1),
704 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
705 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
706 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
707 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
708 
709 	/* Op1 = 0, CRn = 0, CRm = 4 */
710 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0,
711 			       &id_aa64pfr0_override),
712 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1,
713 			       &id_aa64pfr1_override),
714 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0,
715 			       &id_aa64zfr0_override),
716 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64SMFR0_EL1, ftr_id_aa64smfr0,
717 			       &id_aa64smfr0_override),
718 
719 	/* Op1 = 0, CRn = 0, CRm = 5 */
720 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
721 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
722 
723 	/* Op1 = 0, CRn = 0, CRm = 6 */
724 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
725 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1,
726 			       &id_aa64isar1_override),
727 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2,
728 			       &id_aa64isar2_override),
729 
730 	/* Op1 = 0, CRn = 0, CRm = 7 */
731 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
732 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1,
733 			       &id_aa64mmfr1_override),
734 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
735 	ARM64_FTR_REG(SYS_ID_AA64MMFR3_EL1, ftr_id_aa64mmfr3),
736 
737 	/* Op1 = 0, CRn = 1, CRm = 2 */
738 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
739 	ARM64_FTR_REG(SYS_SMCR_EL1, ftr_smcr),
740 
741 	/* Op1 = 1, CRn = 0, CRm = 0 */
742 	ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
743 
744 	/* Op1 = 3, CRn = 0, CRm = 0 */
745 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
746 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
747 
748 	/* Op1 = 3, CRn = 14, CRm = 0 */
749 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
750 };
751 
752 static int search_cmp_ftr_reg(const void *id, const void *regp)
753 {
754 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
755 }
756 
757 /*
758  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
759  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
760  * ascending order of sys_id, we use binary search to find a matching
761  * entry.
762  *
763  * returns - Upon success,  matching ftr_reg entry for id.
764  *         - NULL on failure. It is upto the caller to decide
765  *	     the impact of a failure.
766  */
767 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
768 {
769 	const struct __ftr_reg_entry *ret;
770 
771 	ret = bsearch((const void *)(unsigned long)sys_id,
772 			arm64_ftr_regs,
773 			ARRAY_SIZE(arm64_ftr_regs),
774 			sizeof(arm64_ftr_regs[0]),
775 			search_cmp_ftr_reg);
776 	if (ret)
777 		return ret->reg;
778 	return NULL;
779 }
780 
781 /*
782  * get_arm64_ftr_reg - Looks up a feature register entry using
783  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
784  *
785  * returns - Upon success,  matching ftr_reg entry for id.
786  *         - NULL on failure but with an WARN_ON().
787  */
788 struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
789 {
790 	struct arm64_ftr_reg *reg;
791 
792 	reg = get_arm64_ftr_reg_nowarn(sys_id);
793 
794 	/*
795 	 * Requesting a non-existent register search is an error. Warn
796 	 * and let the caller handle it.
797 	 */
798 	WARN_ON(!reg);
799 	return reg;
800 }
801 
802 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
803 			       s64 ftr_val)
804 {
805 	u64 mask = arm64_ftr_mask(ftrp);
806 
807 	reg &= ~mask;
808 	reg |= (ftr_val << ftrp->shift) & mask;
809 	return reg;
810 }
811 
812 s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
813 				s64 cur)
814 {
815 	s64 ret = 0;
816 
817 	switch (ftrp->type) {
818 	case FTR_EXACT:
819 		ret = ftrp->safe_val;
820 		break;
821 	case FTR_LOWER_SAFE:
822 		ret = min(new, cur);
823 		break;
824 	case FTR_HIGHER_OR_ZERO_SAFE:
825 		if (!cur || !new)
826 			break;
827 		fallthrough;
828 	case FTR_HIGHER_SAFE:
829 		ret = max(new, cur);
830 		break;
831 	default:
832 		BUG();
833 	}
834 
835 	return ret;
836 }
837 
838 static void __init sort_ftr_regs(void)
839 {
840 	unsigned int i;
841 
842 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
843 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
844 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
845 		unsigned int j = 0;
846 
847 		/*
848 		 * Features here must be sorted in descending order with respect
849 		 * to their shift values and should not overlap with each other.
850 		 */
851 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
852 			unsigned int width = ftr_reg->ftr_bits[j].width;
853 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
854 			unsigned int prev_shift;
855 
856 			WARN((shift  + width) > 64,
857 				"%s has invalid feature at shift %d\n",
858 				ftr_reg->name, shift);
859 
860 			/*
861 			 * Skip the first feature. There is nothing to
862 			 * compare against for now.
863 			 */
864 			if (j == 0)
865 				continue;
866 
867 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
868 			WARN((shift + width) > prev_shift,
869 				"%s has feature overlap at shift %d\n",
870 				ftr_reg->name, shift);
871 		}
872 
873 		/*
874 		 * Skip the first register. There is nothing to
875 		 * compare against for now.
876 		 */
877 		if (i == 0)
878 			continue;
879 		/*
880 		 * Registers here must be sorted in ascending order with respect
881 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
882 		 * to work correctly.
883 		 */
884 		BUG_ON(arm64_ftr_regs[i].sys_id <= arm64_ftr_regs[i - 1].sys_id);
885 	}
886 }
887 
888 /*
889  * Initialise the CPU feature register from Boot CPU values.
890  * Also initiliases the strict_mask for the register.
891  * Any bits that are not covered by an arm64_ftr_bits entry are considered
892  * RES0 for the system-wide value, and must strictly match.
893  */
894 static void init_cpu_ftr_reg(u32 sys_reg, u64 new)
895 {
896 	u64 val = 0;
897 	u64 strict_mask = ~0x0ULL;
898 	u64 user_mask = 0;
899 	u64 valid_mask = 0;
900 
901 	const struct arm64_ftr_bits *ftrp;
902 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
903 
904 	if (!reg)
905 		return;
906 
907 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
908 		u64 ftr_mask = arm64_ftr_mask(ftrp);
909 		s64 ftr_new = arm64_ftr_value(ftrp, new);
910 		s64 ftr_ovr = arm64_ftr_value(ftrp, reg->override->val);
911 
912 		if ((ftr_mask & reg->override->mask) == ftr_mask) {
913 			s64 tmp = arm64_ftr_safe_value(ftrp, ftr_ovr, ftr_new);
914 			char *str = NULL;
915 
916 			if (ftr_ovr != tmp) {
917 				/* Unsafe, remove the override */
918 				reg->override->mask &= ~ftr_mask;
919 				reg->override->val &= ~ftr_mask;
920 				tmp = ftr_ovr;
921 				str = "ignoring override";
922 			} else if (ftr_new != tmp) {
923 				/* Override was valid */
924 				ftr_new = tmp;
925 				str = "forced";
926 			} else if (ftr_ovr == tmp) {
927 				/* Override was the safe value */
928 				str = "already set";
929 			}
930 
931 			if (str)
932 				pr_warn("%s[%d:%d]: %s to %llx\n",
933 					reg->name,
934 					ftrp->shift + ftrp->width - 1,
935 					ftrp->shift, str, tmp);
936 		} else if ((ftr_mask & reg->override->val) == ftr_mask) {
937 			reg->override->val &= ~ftr_mask;
938 			pr_warn("%s[%d:%d]: impossible override, ignored\n",
939 				reg->name,
940 				ftrp->shift + ftrp->width - 1,
941 				ftrp->shift);
942 		}
943 
944 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
945 
946 		valid_mask |= ftr_mask;
947 		if (!ftrp->strict)
948 			strict_mask &= ~ftr_mask;
949 		if (ftrp->visible)
950 			user_mask |= ftr_mask;
951 		else
952 			reg->user_val = arm64_ftr_set_value(ftrp,
953 							    reg->user_val,
954 							    ftrp->safe_val);
955 	}
956 
957 	val &= valid_mask;
958 
959 	reg->sys_val = val;
960 	reg->strict_mask = strict_mask;
961 	reg->user_mask = user_mask;
962 }
963 
964 extern const struct arm64_cpu_capabilities arm64_errata[];
965 static const struct arm64_cpu_capabilities arm64_features[];
966 
967 static void __init
968 init_cpucap_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
969 {
970 	for (; caps->matches; caps++) {
971 		if (WARN(caps->capability >= ARM64_NCAPS,
972 			"Invalid capability %d\n", caps->capability))
973 			continue;
974 		if (WARN(cpucap_ptrs[caps->capability],
975 			"Duplicate entry for capability %d\n",
976 			caps->capability))
977 			continue;
978 		cpucap_ptrs[caps->capability] = caps;
979 	}
980 }
981 
982 static void __init init_cpucap_indirect_list(void)
983 {
984 	init_cpucap_indirect_list_from_array(arm64_features);
985 	init_cpucap_indirect_list_from_array(arm64_errata);
986 }
987 
988 static void __init setup_boot_cpu_capabilities(void);
989 
990 static void init_32bit_cpu_features(struct cpuinfo_32bit *info)
991 {
992 	init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
993 	init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
994 	init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
995 	init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
996 	init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
997 	init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
998 	init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
999 	init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
1000 	init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
1001 	init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
1002 	init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
1003 	init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
1004 	init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
1005 	init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
1006 	init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
1007 	init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
1008 	init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
1009 	init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
1010 	init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
1011 	init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
1012 	init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
1013 }
1014 
1015 void __init init_cpu_features(struct cpuinfo_arm64 *info)
1016 {
1017 	/* Before we start using the tables, make sure it is sorted */
1018 	sort_ftr_regs();
1019 
1020 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
1021 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
1022 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
1023 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
1024 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
1025 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
1026 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
1027 	init_cpu_ftr_reg(SYS_ID_AA64ISAR2_EL1, info->reg_id_aa64isar2);
1028 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
1029 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
1030 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
1031 	init_cpu_ftr_reg(SYS_ID_AA64MMFR3_EL1, info->reg_id_aa64mmfr3);
1032 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
1033 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
1034 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
1035 	init_cpu_ftr_reg(SYS_ID_AA64SMFR0_EL1, info->reg_id_aa64smfr0);
1036 
1037 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
1038 		init_32bit_cpu_features(&info->aarch32);
1039 
1040 	if (IS_ENABLED(CONFIG_ARM64_SVE) &&
1041 	    id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
1042 		info->reg_zcr = read_zcr_features();
1043 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
1044 		vec_init_vq_map(ARM64_VEC_SVE);
1045 	}
1046 
1047 	if (IS_ENABLED(CONFIG_ARM64_SME) &&
1048 	    id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1))) {
1049 		info->reg_smcr = read_smcr_features();
1050 		/*
1051 		 * We mask out SMPS since even if the hardware
1052 		 * supports priorities the kernel does not at present
1053 		 * and we block access to them.
1054 		 */
1055 		info->reg_smidr = read_cpuid(SMIDR_EL1) & ~SMIDR_EL1_SMPS;
1056 		init_cpu_ftr_reg(SYS_SMCR_EL1, info->reg_smcr);
1057 		vec_init_vq_map(ARM64_VEC_SME);
1058 	}
1059 
1060 	if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
1061 		init_cpu_ftr_reg(SYS_GMID_EL1, info->reg_gmid);
1062 
1063 	/*
1064 	 * Initialize the indirect array of CPU capabilities pointers before we
1065 	 * handle the boot CPU below.
1066 	 */
1067 	init_cpucap_indirect_list();
1068 
1069 	/*
1070 	 * Detect and enable early CPU capabilities based on the boot CPU,
1071 	 * after we have initialised the CPU feature infrastructure.
1072 	 */
1073 	setup_boot_cpu_capabilities();
1074 }
1075 
1076 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
1077 {
1078 	const struct arm64_ftr_bits *ftrp;
1079 
1080 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
1081 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
1082 		s64 ftr_new = arm64_ftr_value(ftrp, new);
1083 
1084 		if (ftr_cur == ftr_new)
1085 			continue;
1086 		/* Find a safe value */
1087 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
1088 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
1089 	}
1090 
1091 }
1092 
1093 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
1094 {
1095 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
1096 
1097 	if (!regp)
1098 		return 0;
1099 
1100 	update_cpu_ftr_reg(regp, val);
1101 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
1102 		return 0;
1103 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
1104 			regp->name, boot, cpu, val);
1105 	return 1;
1106 }
1107 
1108 static void relax_cpu_ftr_reg(u32 sys_id, int field)
1109 {
1110 	const struct arm64_ftr_bits *ftrp;
1111 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
1112 
1113 	if (!regp)
1114 		return;
1115 
1116 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
1117 		if (ftrp->shift == field) {
1118 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
1119 			break;
1120 		}
1121 	}
1122 
1123 	/* Bogus field? */
1124 	WARN_ON(!ftrp->width);
1125 }
1126 
1127 static void lazy_init_32bit_cpu_features(struct cpuinfo_arm64 *info,
1128 					 struct cpuinfo_arm64 *boot)
1129 {
1130 	static bool boot_cpu_32bit_regs_overridden = false;
1131 
1132 	if (!allow_mismatched_32bit_el0 || boot_cpu_32bit_regs_overridden)
1133 		return;
1134 
1135 	if (id_aa64pfr0_32bit_el0(boot->reg_id_aa64pfr0))
1136 		return;
1137 
1138 	boot->aarch32 = info->aarch32;
1139 	init_32bit_cpu_features(&boot->aarch32);
1140 	boot_cpu_32bit_regs_overridden = true;
1141 }
1142 
1143 static int update_32bit_cpu_features(int cpu, struct cpuinfo_32bit *info,
1144 				     struct cpuinfo_32bit *boot)
1145 {
1146 	int taint = 0;
1147 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1148 
1149 	/*
1150 	 * If we don't have AArch32 at EL1, then relax the strictness of
1151 	 * EL1-dependent register fields to avoid spurious sanity check fails.
1152 	 */
1153 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
1154 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_EL1_SMC_SHIFT);
1155 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_EL1_Virt_frac_SHIFT);
1156 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_EL1_Sec_frac_SHIFT);
1157 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_EL1_Virtualization_SHIFT);
1158 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_EL1_Security_SHIFT);
1159 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_EL1_ProgMod_SHIFT);
1160 	}
1161 
1162 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
1163 				      info->reg_id_dfr0, boot->reg_id_dfr0);
1164 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
1165 				      info->reg_id_dfr1, boot->reg_id_dfr1);
1166 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
1167 				      info->reg_id_isar0, boot->reg_id_isar0);
1168 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
1169 				      info->reg_id_isar1, boot->reg_id_isar1);
1170 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
1171 				      info->reg_id_isar2, boot->reg_id_isar2);
1172 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
1173 				      info->reg_id_isar3, boot->reg_id_isar3);
1174 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
1175 				      info->reg_id_isar4, boot->reg_id_isar4);
1176 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
1177 				      info->reg_id_isar5, boot->reg_id_isar5);
1178 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
1179 				      info->reg_id_isar6, boot->reg_id_isar6);
1180 
1181 	/*
1182 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
1183 	 * ACTLR formats could differ across CPUs and therefore would have to
1184 	 * be trapped for virtualization anyway.
1185 	 */
1186 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
1187 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
1188 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
1189 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
1190 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
1191 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
1192 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
1193 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
1194 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
1195 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
1196 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
1197 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
1198 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
1199 				      info->reg_id_pfr0, boot->reg_id_pfr0);
1200 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
1201 				      info->reg_id_pfr1, boot->reg_id_pfr1);
1202 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
1203 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1204 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1205 				      info->reg_mvfr0, boot->reg_mvfr0);
1206 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1207 				      info->reg_mvfr1, boot->reg_mvfr1);
1208 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1209 				      info->reg_mvfr2, boot->reg_mvfr2);
1210 
1211 	return taint;
1212 }
1213 
1214 /*
1215  * Update system wide CPU feature registers with the values from a
1216  * non-boot CPU. Also performs SANITY checks to make sure that there
1217  * aren't any insane variations from that of the boot CPU.
1218  */
1219 void update_cpu_features(int cpu,
1220 			 struct cpuinfo_arm64 *info,
1221 			 struct cpuinfo_arm64 *boot)
1222 {
1223 	int taint = 0;
1224 
1225 	/*
1226 	 * The kernel can handle differing I-cache policies, but otherwise
1227 	 * caches should look identical. Userspace JITs will make use of
1228 	 * *minLine.
1229 	 */
1230 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1231 				      info->reg_ctr, boot->reg_ctr);
1232 
1233 	/*
1234 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1235 	 * could result in too much or too little memory being zeroed if a
1236 	 * process is preempted and migrated between CPUs.
1237 	 */
1238 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1239 				      info->reg_dczid, boot->reg_dczid);
1240 
1241 	/* If different, timekeeping will be broken (especially with KVM) */
1242 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1243 				      info->reg_cntfrq, boot->reg_cntfrq);
1244 
1245 	/*
1246 	 * The kernel uses self-hosted debug features and expects CPUs to
1247 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1248 	 * and BRPs to be identical.
1249 	 * ID_AA64DFR1 is currently RES0.
1250 	 */
1251 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1252 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1253 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1254 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1255 	/*
1256 	 * Even in big.LITTLE, processors should be identical instruction-set
1257 	 * wise.
1258 	 */
1259 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1260 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1261 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1262 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1263 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR2_EL1, cpu,
1264 				      info->reg_id_aa64isar2, boot->reg_id_aa64isar2);
1265 
1266 	/*
1267 	 * Differing PARange support is fine as long as all peripherals and
1268 	 * memory are mapped within the minimum PARange of all CPUs.
1269 	 * Linux should not care about secure memory.
1270 	 */
1271 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1272 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1273 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1274 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1275 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1276 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1277 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR3_EL1, cpu,
1278 				      info->reg_id_aa64mmfr3, boot->reg_id_aa64mmfr3);
1279 
1280 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1281 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1282 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1283 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1284 
1285 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1286 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1287 
1288 	taint |= check_update_ftr_reg(SYS_ID_AA64SMFR0_EL1, cpu,
1289 				      info->reg_id_aa64smfr0, boot->reg_id_aa64smfr0);
1290 
1291 	if (IS_ENABLED(CONFIG_ARM64_SVE) &&
1292 	    id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
1293 		info->reg_zcr = read_zcr_features();
1294 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1295 					info->reg_zcr, boot->reg_zcr);
1296 
1297 		/* Probe vector lengths */
1298 		if (!system_capabilities_finalized())
1299 			vec_update_vq_map(ARM64_VEC_SVE);
1300 	}
1301 
1302 	if (IS_ENABLED(CONFIG_ARM64_SME) &&
1303 	    id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1))) {
1304 		info->reg_smcr = read_smcr_features();
1305 		/*
1306 		 * We mask out SMPS since even if the hardware
1307 		 * supports priorities the kernel does not at present
1308 		 * and we block access to them.
1309 		 */
1310 		info->reg_smidr = read_cpuid(SMIDR_EL1) & ~SMIDR_EL1_SMPS;
1311 		taint |= check_update_ftr_reg(SYS_SMCR_EL1, cpu,
1312 					info->reg_smcr, boot->reg_smcr);
1313 
1314 		/* Probe vector lengths */
1315 		if (!system_capabilities_finalized())
1316 			vec_update_vq_map(ARM64_VEC_SME);
1317 	}
1318 
1319 	/*
1320 	 * The kernel uses the LDGM/STGM instructions and the number of tags
1321 	 * they read/write depends on the GMID_EL1.BS field. Check that the
1322 	 * value is the same on all CPUs.
1323 	 */
1324 	if (IS_ENABLED(CONFIG_ARM64_MTE) &&
1325 	    id_aa64pfr1_mte(info->reg_id_aa64pfr1)) {
1326 		taint |= check_update_ftr_reg(SYS_GMID_EL1, cpu,
1327 					      info->reg_gmid, boot->reg_gmid);
1328 	}
1329 
1330 	/*
1331 	 * If we don't have AArch32 at all then skip the checks entirely
1332 	 * as the register values may be UNKNOWN and we're not going to be
1333 	 * using them for anything.
1334 	 *
1335 	 * This relies on a sanitised view of the AArch64 ID registers
1336 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1337 	 */
1338 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
1339 		lazy_init_32bit_cpu_features(info, boot);
1340 		taint |= update_32bit_cpu_features(cpu, &info->aarch32,
1341 						   &boot->aarch32);
1342 	}
1343 
1344 	/*
1345 	 * Mismatched CPU features are a recipe for disaster. Don't even
1346 	 * pretend to support them.
1347 	 */
1348 	if (taint) {
1349 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1350 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1351 	}
1352 }
1353 
1354 u64 read_sanitised_ftr_reg(u32 id)
1355 {
1356 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1357 
1358 	if (!regp)
1359 		return 0;
1360 	return regp->sys_val;
1361 }
1362 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
1363 
1364 #define read_sysreg_case(r)	\
1365 	case r:		val = read_sysreg_s(r); break;
1366 
1367 /*
1368  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1369  * Read the system register on the current CPU
1370  */
1371 u64 __read_sysreg_by_encoding(u32 sys_id)
1372 {
1373 	struct arm64_ftr_reg *regp;
1374 	u64 val;
1375 
1376 	switch (sys_id) {
1377 	read_sysreg_case(SYS_ID_PFR0_EL1);
1378 	read_sysreg_case(SYS_ID_PFR1_EL1);
1379 	read_sysreg_case(SYS_ID_PFR2_EL1);
1380 	read_sysreg_case(SYS_ID_DFR0_EL1);
1381 	read_sysreg_case(SYS_ID_DFR1_EL1);
1382 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1383 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1384 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1385 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1386 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1387 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1388 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1389 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1390 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1391 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1392 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1393 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1394 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1395 	read_sysreg_case(SYS_MVFR0_EL1);
1396 	read_sysreg_case(SYS_MVFR1_EL1);
1397 	read_sysreg_case(SYS_MVFR2_EL1);
1398 
1399 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1400 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1401 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1402 	read_sysreg_case(SYS_ID_AA64SMFR0_EL1);
1403 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1404 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1405 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1406 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1407 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1408 	read_sysreg_case(SYS_ID_AA64MMFR3_EL1);
1409 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1410 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1411 	read_sysreg_case(SYS_ID_AA64ISAR2_EL1);
1412 
1413 	read_sysreg_case(SYS_CNTFRQ_EL0);
1414 	read_sysreg_case(SYS_CTR_EL0);
1415 	read_sysreg_case(SYS_DCZID_EL0);
1416 
1417 	default:
1418 		BUG();
1419 		return 0;
1420 	}
1421 
1422 	regp  = get_arm64_ftr_reg(sys_id);
1423 	if (regp) {
1424 		val &= ~regp->override->mask;
1425 		val |= (regp->override->val & regp->override->mask);
1426 	}
1427 
1428 	return val;
1429 }
1430 
1431 #include <linux/irqchip/arm-gic-v3.h>
1432 
1433 static bool
1434 has_always(const struct arm64_cpu_capabilities *entry, int scope)
1435 {
1436 	return true;
1437 }
1438 
1439 static bool
1440 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1441 {
1442 	int val = cpuid_feature_extract_field_width(reg, entry->field_pos,
1443 						    entry->field_width,
1444 						    entry->sign);
1445 
1446 	return val >= entry->min_field_value;
1447 }
1448 
1449 static u64
1450 read_scoped_sysreg(const struct arm64_cpu_capabilities *entry, int scope)
1451 {
1452 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1453 	if (scope == SCOPE_SYSTEM)
1454 		return read_sanitised_ftr_reg(entry->sys_reg);
1455 	else
1456 		return __read_sysreg_by_encoding(entry->sys_reg);
1457 }
1458 
1459 static bool
1460 has_user_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1461 {
1462 	int mask;
1463 	struct arm64_ftr_reg *regp;
1464 	u64 val = read_scoped_sysreg(entry, scope);
1465 
1466 	regp = get_arm64_ftr_reg(entry->sys_reg);
1467 	if (!regp)
1468 		return false;
1469 
1470 	mask = cpuid_feature_extract_unsigned_field_width(regp->user_mask,
1471 							  entry->field_pos,
1472 							  entry->field_width);
1473 	if (!mask)
1474 		return false;
1475 
1476 	return feature_matches(val, entry);
1477 }
1478 
1479 static bool
1480 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1481 {
1482 	u64 val = read_scoped_sysreg(entry, scope);
1483 	return feature_matches(val, entry);
1484 }
1485 
1486 const struct cpumask *system_32bit_el0_cpumask(void)
1487 {
1488 	if (!system_supports_32bit_el0())
1489 		return cpu_none_mask;
1490 
1491 	if (static_branch_unlikely(&arm64_mismatched_32bit_el0))
1492 		return cpu_32bit_el0_mask;
1493 
1494 	return cpu_possible_mask;
1495 }
1496 
1497 static int __init parse_32bit_el0_param(char *str)
1498 {
1499 	allow_mismatched_32bit_el0 = true;
1500 	return 0;
1501 }
1502 early_param("allow_mismatched_32bit_el0", parse_32bit_el0_param);
1503 
1504 static ssize_t aarch32_el0_show(struct device *dev,
1505 				struct device_attribute *attr, char *buf)
1506 {
1507 	const struct cpumask *mask = system_32bit_el0_cpumask();
1508 
1509 	return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(mask));
1510 }
1511 static const DEVICE_ATTR_RO(aarch32_el0);
1512 
1513 static int __init aarch32_el0_sysfs_init(void)
1514 {
1515 	struct device *dev_root;
1516 	int ret = 0;
1517 
1518 	if (!allow_mismatched_32bit_el0)
1519 		return 0;
1520 
1521 	dev_root = bus_get_dev_root(&cpu_subsys);
1522 	if (dev_root) {
1523 		ret = device_create_file(dev_root, &dev_attr_aarch32_el0);
1524 		put_device(dev_root);
1525 	}
1526 	return ret;
1527 }
1528 device_initcall(aarch32_el0_sysfs_init);
1529 
1530 static bool has_32bit_el0(const struct arm64_cpu_capabilities *entry, int scope)
1531 {
1532 	if (!has_cpuid_feature(entry, scope))
1533 		return allow_mismatched_32bit_el0;
1534 
1535 	if (scope == SCOPE_SYSTEM)
1536 		pr_info("detected: 32-bit EL0 Support\n");
1537 
1538 	return true;
1539 }
1540 
1541 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1542 {
1543 	bool has_sre;
1544 
1545 	if (!has_cpuid_feature(entry, scope))
1546 		return false;
1547 
1548 	has_sre = gic_enable_sre();
1549 	if (!has_sre)
1550 		pr_warn_once("%s present but disabled by higher exception level\n",
1551 			     entry->desc);
1552 
1553 	return has_sre;
1554 }
1555 
1556 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1557 {
1558 	u32 midr = read_cpuid_id();
1559 
1560 	/* Cavium ThunderX pass 1.x and 2.x */
1561 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1562 		MIDR_CPU_VAR_REV(0, 0),
1563 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1564 }
1565 
1566 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1567 {
1568 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1569 
1570 	return cpuid_feature_extract_signed_field(pfr0,
1571 					ID_AA64PFR0_EL1_FP_SHIFT) < 0;
1572 }
1573 
1574 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1575 			  int scope)
1576 {
1577 	u64 ctr;
1578 
1579 	if (scope == SCOPE_SYSTEM)
1580 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1581 	else
1582 		ctr = read_cpuid_effective_cachetype();
1583 
1584 	return ctr & BIT(CTR_EL0_IDC_SHIFT);
1585 }
1586 
1587 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1588 {
1589 	/*
1590 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1591 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1592 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1593 	 * value.
1594 	 */
1595 	if (!(read_cpuid_cachetype() & BIT(CTR_EL0_IDC_SHIFT)))
1596 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1597 }
1598 
1599 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1600 			  int scope)
1601 {
1602 	u64 ctr;
1603 
1604 	if (scope == SCOPE_SYSTEM)
1605 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1606 	else
1607 		ctr = read_cpuid_cachetype();
1608 
1609 	return ctr & BIT(CTR_EL0_DIC_SHIFT);
1610 }
1611 
1612 static bool __maybe_unused
1613 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1614 {
1615 	/*
1616 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1617 	 * may share TLB entries with a CPU stuck in the crashed
1618 	 * kernel.
1619 	 */
1620 	if (is_kdump_kernel())
1621 		return false;
1622 
1623 	if (cpus_have_const_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
1624 		return false;
1625 
1626 	return has_cpuid_feature(entry, scope);
1627 }
1628 
1629 /*
1630  * This check is triggered during the early boot before the cpufeature
1631  * is initialised. Checking the status on the local CPU allows the boot
1632  * CPU to detect the need for non-global mappings and thus avoiding a
1633  * pagetable re-write after all the CPUs are booted. This check will be
1634  * anyway run on individual CPUs, allowing us to get the consistent
1635  * state once the SMP CPUs are up and thus make the switch to non-global
1636  * mappings if required.
1637  */
1638 bool kaslr_requires_kpti(void)
1639 {
1640 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1641 		return false;
1642 
1643 	/*
1644 	 * E0PD does a similar job to KPTI so can be used instead
1645 	 * where available.
1646 	 */
1647 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1648 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1649 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1650 						ID_AA64MMFR2_EL1_E0PD_SHIFT))
1651 			return false;
1652 	}
1653 
1654 	/*
1655 	 * Systems affected by Cavium erratum 24756 are incompatible
1656 	 * with KPTI.
1657 	 */
1658 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1659 		extern const struct midr_range cavium_erratum_27456_cpus[];
1660 
1661 		if (is_midr_in_range_list(read_cpuid_id(),
1662 					  cavium_erratum_27456_cpus))
1663 			return false;
1664 	}
1665 
1666 	return kaslr_enabled();
1667 }
1668 
1669 static bool __meltdown_safe = true;
1670 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1671 
1672 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1673 				int scope)
1674 {
1675 	/* List of CPUs that are not vulnerable and don't need KPTI */
1676 	static const struct midr_range kpti_safe_list[] = {
1677 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1678 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1679 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1680 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1681 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1682 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1683 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1684 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1685 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1686 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1687 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1688 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_GOLD),
1689 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
1690 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1691 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1692 		{ /* sentinel */ }
1693 	};
1694 	char const *str = "kpti command line option";
1695 	bool meltdown_safe;
1696 
1697 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1698 
1699 	/* Defer to CPU feature registers */
1700 	if (has_cpuid_feature(entry, scope))
1701 		meltdown_safe = true;
1702 
1703 	if (!meltdown_safe)
1704 		__meltdown_safe = false;
1705 
1706 	/*
1707 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1708 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1709 	 * ends as well as you might imagine. Don't even try. We cannot rely
1710 	 * on the cpus_have_*cap() helpers here to detect the CPU erratum
1711 	 * because cpucap detection order may change. However, since we know
1712 	 * affected CPUs are always in a homogeneous configuration, it is
1713 	 * safe to rely on this_cpu_has_cap() here.
1714 	 */
1715 	if (this_cpu_has_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1716 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1717 		__kpti_forced = -1;
1718 	}
1719 
1720 	/* Useful for KASLR robustness */
1721 	if (kaslr_requires_kpti()) {
1722 		if (!__kpti_forced) {
1723 			str = "KASLR";
1724 			__kpti_forced = 1;
1725 		}
1726 	}
1727 
1728 	if (cpu_mitigations_off() && !__kpti_forced) {
1729 		str = "mitigations=off";
1730 		__kpti_forced = -1;
1731 	}
1732 
1733 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1734 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1735 		return false;
1736 	}
1737 
1738 	/* Forced? */
1739 	if (__kpti_forced) {
1740 		pr_info_once("kernel page table isolation forced %s by %s\n",
1741 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1742 		return __kpti_forced > 0;
1743 	}
1744 
1745 	return !meltdown_safe;
1746 }
1747 
1748 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1749 #define KPTI_NG_TEMP_VA		(-(1UL << PMD_SHIFT))
1750 
1751 extern
1752 void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt,
1753 			     phys_addr_t size, pgprot_t prot,
1754 			     phys_addr_t (*pgtable_alloc)(int), int flags);
1755 
1756 static phys_addr_t kpti_ng_temp_alloc;
1757 
1758 static phys_addr_t kpti_ng_pgd_alloc(int shift)
1759 {
1760 	kpti_ng_temp_alloc -= PAGE_SIZE;
1761 	return kpti_ng_temp_alloc;
1762 }
1763 
1764 static void
1765 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1766 {
1767 	typedef void (kpti_remap_fn)(int, int, phys_addr_t, unsigned long);
1768 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1769 	kpti_remap_fn *remap_fn;
1770 
1771 	int cpu = smp_processor_id();
1772 	int levels = CONFIG_PGTABLE_LEVELS;
1773 	int order = order_base_2(levels);
1774 	u64 kpti_ng_temp_pgd_pa = 0;
1775 	pgd_t *kpti_ng_temp_pgd;
1776 	u64 alloc = 0;
1777 
1778 	if (__this_cpu_read(this_cpu_vector) == vectors) {
1779 		const char *v = arm64_get_bp_hardening_vector(EL1_VECTOR_KPTI);
1780 
1781 		__this_cpu_write(this_cpu_vector, v);
1782 	}
1783 
1784 	/*
1785 	 * We don't need to rewrite the page-tables if either we've done
1786 	 * it already or we have KASLR enabled and therefore have not
1787 	 * created any global mappings at all.
1788 	 */
1789 	if (arm64_use_ng_mappings)
1790 		return;
1791 
1792 	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
1793 
1794 	if (!cpu) {
1795 		alloc = __get_free_pages(GFP_ATOMIC | __GFP_ZERO, order);
1796 		kpti_ng_temp_pgd = (pgd_t *)(alloc + (levels - 1) * PAGE_SIZE);
1797 		kpti_ng_temp_alloc = kpti_ng_temp_pgd_pa = __pa(kpti_ng_temp_pgd);
1798 
1799 		//
1800 		// Create a minimal page table hierarchy that permits us to map
1801 		// the swapper page tables temporarily as we traverse them.
1802 		//
1803 		// The physical pages are laid out as follows:
1804 		//
1805 		// +--------+-/-------+-/------ +-\\--------+
1806 		// :  PTE[] : | PMD[] : | PUD[] : || PGD[]  :
1807 		// +--------+-\-------+-\------ +-//--------+
1808 		//      ^
1809 		// The first page is mapped into this hierarchy at a PMD_SHIFT
1810 		// aligned virtual address, so that we can manipulate the PTE
1811 		// level entries while the mapping is active. The first entry
1812 		// covers the PTE[] page itself, the remaining entries are free
1813 		// to be used as a ad-hoc fixmap.
1814 		//
1815 		create_kpti_ng_temp_pgd(kpti_ng_temp_pgd, __pa(alloc),
1816 					KPTI_NG_TEMP_VA, PAGE_SIZE, PAGE_KERNEL,
1817 					kpti_ng_pgd_alloc, 0);
1818 	}
1819 
1820 	cpu_install_idmap();
1821 	remap_fn(cpu, num_online_cpus(), kpti_ng_temp_pgd_pa, KPTI_NG_TEMP_VA);
1822 	cpu_uninstall_idmap();
1823 
1824 	if (!cpu) {
1825 		free_pages(alloc, order);
1826 		arm64_use_ng_mappings = true;
1827 	}
1828 }
1829 #else
1830 static void
1831 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1832 {
1833 }
1834 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1835 
1836 static int __init parse_kpti(char *str)
1837 {
1838 	bool enabled;
1839 	int ret = kstrtobool(str, &enabled);
1840 
1841 	if (ret)
1842 		return ret;
1843 
1844 	__kpti_forced = enabled ? 1 : -1;
1845 	return 0;
1846 }
1847 early_param("kpti", parse_kpti);
1848 
1849 #ifdef CONFIG_ARM64_HW_AFDBM
1850 static inline void __cpu_enable_hw_dbm(void)
1851 {
1852 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1853 
1854 	write_sysreg(tcr, tcr_el1);
1855 	isb();
1856 	local_flush_tlb_all();
1857 }
1858 
1859 static bool cpu_has_broken_dbm(void)
1860 {
1861 	/* List of CPUs which have broken DBM support. */
1862 	static const struct midr_range cpus[] = {
1863 #ifdef CONFIG_ARM64_ERRATUM_1024718
1864 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1865 		/* Kryo4xx Silver (rdpe => r1p0) */
1866 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1867 #endif
1868 #ifdef CONFIG_ARM64_ERRATUM_2051678
1869 		MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 2),
1870 #endif
1871 		{},
1872 	};
1873 
1874 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1875 }
1876 
1877 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1878 {
1879 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1880 	       !cpu_has_broken_dbm();
1881 }
1882 
1883 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1884 {
1885 	if (cpu_can_use_dbm(cap))
1886 		__cpu_enable_hw_dbm();
1887 }
1888 
1889 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1890 		       int __unused)
1891 {
1892 	static bool detected = false;
1893 	/*
1894 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1895 	 * run a mix of CPUs with and without the feature. So, we
1896 	 * unconditionally enable the capability to allow any late CPU
1897 	 * to use the feature. We only enable the control bits on the
1898 	 * CPU, if it actually supports.
1899 	 *
1900 	 * We have to make sure we print the "feature" detection only
1901 	 * when at least one CPU actually uses it. So check if this CPU
1902 	 * can actually use it and print the message exactly once.
1903 	 *
1904 	 * This is safe as all CPUs (including secondary CPUs - due to the
1905 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1906 	 * goes through the "matches" check exactly once. Also if a CPU
1907 	 * matches the criteria, it is guaranteed that the CPU will turn
1908 	 * the DBM on, as the capability is unconditionally enabled.
1909 	 */
1910 	if (!detected && cpu_can_use_dbm(cap)) {
1911 		detected = true;
1912 		pr_info("detected: Hardware dirty bit management\n");
1913 	}
1914 
1915 	return true;
1916 }
1917 
1918 #endif
1919 
1920 #ifdef CONFIG_ARM64_AMU_EXTN
1921 
1922 /*
1923  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1924  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1925  * information regarding all the events that it supports. When a CPU bit is
1926  * set in the cpumask, the user of this feature can only rely on the presence
1927  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1928  * counters are enabled or access to these counters is enabled by code
1929  * executed at higher exception levels (firmware).
1930  */
1931 static struct cpumask amu_cpus __read_mostly;
1932 
1933 bool cpu_has_amu_feat(int cpu)
1934 {
1935 	return cpumask_test_cpu(cpu, &amu_cpus);
1936 }
1937 
1938 int get_cpu_with_amu_feat(void)
1939 {
1940 	return cpumask_any(&amu_cpus);
1941 }
1942 
1943 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1944 {
1945 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1946 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1947 			smp_processor_id());
1948 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1949 
1950 		/* 0 reference values signal broken/disabled counters */
1951 		if (!this_cpu_has_cap(ARM64_WORKAROUND_2457168))
1952 			update_freq_counters_refs();
1953 	}
1954 }
1955 
1956 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1957 		    int __unused)
1958 {
1959 	/*
1960 	 * The AMU extension is a non-conflicting feature: the kernel can
1961 	 * safely run a mix of CPUs with and without support for the
1962 	 * activity monitors extension. Therefore, unconditionally enable
1963 	 * the capability to allow any late CPU to use the feature.
1964 	 *
1965 	 * With this feature unconditionally enabled, the cpu_enable
1966 	 * function will be called for all CPUs that match the criteria,
1967 	 * including secondary and hotplugged, marking this feature as
1968 	 * present on that respective CPU. The enable function will also
1969 	 * print a detection message.
1970 	 */
1971 
1972 	return true;
1973 }
1974 #else
1975 int get_cpu_with_amu_feat(void)
1976 {
1977 	return nr_cpu_ids;
1978 }
1979 #endif
1980 
1981 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1982 {
1983 	return is_kernel_in_hyp_mode();
1984 }
1985 
1986 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1987 {
1988 	/*
1989 	 * Copy register values that aren't redirected by hardware.
1990 	 *
1991 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1992 	 * this value to tpidr_el2 before we patch the code. Once we've done
1993 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1994 	 * do anything here.
1995 	 */
1996 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1997 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1998 }
1999 
2000 static bool has_nested_virt_support(const struct arm64_cpu_capabilities *cap,
2001 				    int scope)
2002 {
2003 	if (kvm_get_mode() != KVM_MODE_NV)
2004 		return false;
2005 
2006 	if (!has_cpuid_feature(cap, scope)) {
2007 		pr_warn("unavailable: %s\n", cap->desc);
2008 		return false;
2009 	}
2010 
2011 	return true;
2012 }
2013 
2014 static bool hvhe_possible(const struct arm64_cpu_capabilities *entry,
2015 			  int __unused)
2016 {
2017 	u64 val;
2018 
2019 	val = read_sysreg(id_aa64mmfr1_el1);
2020 	if (!cpuid_feature_extract_unsigned_field(val, ID_AA64MMFR1_EL1_VH_SHIFT))
2021 		return false;
2022 
2023 	val = arm64_sw_feature_override.val & arm64_sw_feature_override.mask;
2024 	return cpuid_feature_extract_unsigned_field(val, ARM64_SW_FEATURE_OVERRIDE_HVHE);
2025 }
2026 
2027 #ifdef CONFIG_ARM64_PAN
2028 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
2029 {
2030 	/*
2031 	 * We modify PSTATE. This won't work from irq context as the PSTATE
2032 	 * is discarded once we return from the exception.
2033 	 */
2034 	WARN_ON_ONCE(in_interrupt());
2035 
2036 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
2037 	set_pstate_pan(1);
2038 }
2039 #endif /* CONFIG_ARM64_PAN */
2040 
2041 #ifdef CONFIG_ARM64_RAS_EXTN
2042 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
2043 {
2044 	/* Firmware may have left a deferred SError in this register. */
2045 	write_sysreg_s(0, SYS_DISR_EL1);
2046 }
2047 #endif /* CONFIG_ARM64_RAS_EXTN */
2048 
2049 #ifdef CONFIG_ARM64_PTR_AUTH
2050 static bool has_address_auth_cpucap(const struct arm64_cpu_capabilities *entry, int scope)
2051 {
2052 	int boot_val, sec_val;
2053 
2054 	/* We don't expect to be called with SCOPE_SYSTEM */
2055 	WARN_ON(scope == SCOPE_SYSTEM);
2056 	/*
2057 	 * The ptr-auth feature levels are not intercompatible with lower
2058 	 * levels. Hence we must match ptr-auth feature level of the secondary
2059 	 * CPUs with that of the boot CPU. The level of boot cpu is fetched
2060 	 * from the sanitised register whereas direct register read is done for
2061 	 * the secondary CPUs.
2062 	 * The sanitised feature state is guaranteed to match that of the
2063 	 * boot CPU as a mismatched secondary CPU is parked before it gets
2064 	 * a chance to update the state, with the capability.
2065 	 */
2066 	boot_val = cpuid_feature_extract_field(read_sanitised_ftr_reg(entry->sys_reg),
2067 					       entry->field_pos, entry->sign);
2068 	if (scope & SCOPE_BOOT_CPU)
2069 		return boot_val >= entry->min_field_value;
2070 	/* Now check for the secondary CPUs with SCOPE_LOCAL_CPU scope */
2071 	sec_val = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg),
2072 					      entry->field_pos, entry->sign);
2073 	return (sec_val >= entry->min_field_value) && (sec_val == boot_val);
2074 }
2075 
2076 static bool has_address_auth_metacap(const struct arm64_cpu_capabilities *entry,
2077 				     int scope)
2078 {
2079 	bool api = has_address_auth_cpucap(cpucap_ptrs[ARM64_HAS_ADDRESS_AUTH_IMP_DEF], scope);
2080 	bool apa = has_address_auth_cpucap(cpucap_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA5], scope);
2081 	bool apa3 = has_address_auth_cpucap(cpucap_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA3], scope);
2082 
2083 	return apa || apa3 || api;
2084 }
2085 
2086 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
2087 			     int __unused)
2088 {
2089 	bool gpi = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
2090 	bool gpa = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH_QARMA5);
2091 	bool gpa3 = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH_QARMA3);
2092 
2093 	return gpa || gpa3 || gpi;
2094 }
2095 #endif /* CONFIG_ARM64_PTR_AUTH */
2096 
2097 #ifdef CONFIG_ARM64_E0PD
2098 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
2099 {
2100 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
2101 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
2102 }
2103 #endif /* CONFIG_ARM64_E0PD */
2104 
2105 #ifdef CONFIG_ARM64_PSEUDO_NMI
2106 static bool enable_pseudo_nmi;
2107 
2108 static int __init early_enable_pseudo_nmi(char *p)
2109 {
2110 	return kstrtobool(p, &enable_pseudo_nmi);
2111 }
2112 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
2113 
2114 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
2115 				   int scope)
2116 {
2117 	/*
2118 	 * ARM64_HAS_GIC_CPUIF_SYSREGS has a lower index, and is a boot CPU
2119 	 * feature, so will be detected earlier.
2120 	 */
2121 	BUILD_BUG_ON(ARM64_HAS_GIC_PRIO_MASKING <= ARM64_HAS_GIC_CPUIF_SYSREGS);
2122 	if (!cpus_have_cap(ARM64_HAS_GIC_CPUIF_SYSREGS))
2123 		return false;
2124 
2125 	return enable_pseudo_nmi;
2126 }
2127 
2128 static bool has_gic_prio_relaxed_sync(const struct arm64_cpu_capabilities *entry,
2129 				      int scope)
2130 {
2131 	/*
2132 	 * If we're not using priority masking then we won't be poking PMR_EL1,
2133 	 * and there's no need to relax synchronization of writes to it, and
2134 	 * ICC_CTLR_EL1 might not be accessible and we must avoid reads from
2135 	 * that.
2136 	 *
2137 	 * ARM64_HAS_GIC_PRIO_MASKING has a lower index, and is a boot CPU
2138 	 * feature, so will be detected earlier.
2139 	 */
2140 	BUILD_BUG_ON(ARM64_HAS_GIC_PRIO_RELAXED_SYNC <= ARM64_HAS_GIC_PRIO_MASKING);
2141 	if (!cpus_have_cap(ARM64_HAS_GIC_PRIO_MASKING))
2142 		return false;
2143 
2144 	/*
2145 	 * When Priority Mask Hint Enable (PMHE) == 0b0, PMR is not used as a
2146 	 * hint for interrupt distribution, a DSB is not necessary when
2147 	 * unmasking IRQs via PMR, and we can relax the barrier to a NOP.
2148 	 *
2149 	 * Linux itself doesn't use 1:N distribution, so has no need to
2150 	 * set PMHE. The only reason to have it set is if EL3 requires it
2151 	 * (and we can't change it).
2152 	 */
2153 	return (gic_read_ctlr() & ICC_CTLR_EL1_PMHE_MASK) == 0;
2154 }
2155 #endif
2156 
2157 #ifdef CONFIG_ARM64_BTI
2158 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
2159 {
2160 	/*
2161 	 * Use of X16/X17 for tail-calls and trampolines that jump to
2162 	 * function entry points using BR is a requirement for
2163 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
2164 	 * So, be strict and forbid other BRs using other registers to
2165 	 * jump onto a PACIxSP instruction:
2166 	 */
2167 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
2168 	isb();
2169 }
2170 #endif /* CONFIG_ARM64_BTI */
2171 
2172 #ifdef CONFIG_ARM64_MTE
2173 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
2174 {
2175 	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0);
2176 
2177 	mte_cpu_setup();
2178 
2179 	/*
2180 	 * Clear the tags in the zero page. This needs to be done via the
2181 	 * linear map which has the Tagged attribute.
2182 	 */
2183 	if (try_page_mte_tagging(ZERO_PAGE(0))) {
2184 		mte_clear_page_tags(lm_alias(empty_zero_page));
2185 		set_page_mte_tagged(ZERO_PAGE(0));
2186 	}
2187 
2188 	kasan_init_hw_tags_cpu();
2189 }
2190 #endif /* CONFIG_ARM64_MTE */
2191 
2192 static void elf_hwcap_fixup(void)
2193 {
2194 #ifdef CONFIG_ARM64_ERRATUM_1742098
2195 	if (cpus_have_const_cap(ARM64_WORKAROUND_1742098))
2196 		compat_elf_hwcap2 &= ~COMPAT_HWCAP2_AES;
2197 #endif /* ARM64_ERRATUM_1742098 */
2198 }
2199 
2200 #ifdef CONFIG_KVM
2201 static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
2202 {
2203 	return kvm_get_mode() == KVM_MODE_PROTECTED;
2204 }
2205 #endif /* CONFIG_KVM */
2206 
2207 static void cpu_trap_el0_impdef(const struct arm64_cpu_capabilities *__unused)
2208 {
2209 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_TIDCP);
2210 }
2211 
2212 static void cpu_enable_dit(const struct arm64_cpu_capabilities *__unused)
2213 {
2214 	set_pstate_dit(1);
2215 }
2216 
2217 static void cpu_enable_mops(const struct arm64_cpu_capabilities *__unused)
2218 {
2219 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_MSCEn);
2220 }
2221 
2222 /* Internal helper functions to match cpu capability type */
2223 static bool
2224 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
2225 {
2226 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
2227 }
2228 
2229 static bool
2230 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
2231 {
2232 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
2233 }
2234 
2235 static bool
2236 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
2237 {
2238 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
2239 }
2240 
2241 static const struct arm64_cpu_capabilities arm64_features[] = {
2242 	{
2243 		.capability = ARM64_ALWAYS_BOOT,
2244 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2245 		.matches = has_always,
2246 	},
2247 	{
2248 		.capability = ARM64_ALWAYS_SYSTEM,
2249 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2250 		.matches = has_always,
2251 	},
2252 	{
2253 		.desc = "GIC system register CPU interface",
2254 		.capability = ARM64_HAS_GIC_CPUIF_SYSREGS,
2255 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2256 		.matches = has_useable_gicv3_cpuif,
2257 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, GIC, IMP)
2258 	},
2259 	{
2260 		.desc = "Enhanced Counter Virtualization",
2261 		.capability = ARM64_HAS_ECV,
2262 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2263 		.matches = has_cpuid_feature,
2264 		ARM64_CPUID_FIELDS(ID_AA64MMFR0_EL1, ECV, IMP)
2265 	},
2266 	{
2267 		.desc = "Enhanced Counter Virtualization (CNTPOFF)",
2268 		.capability = ARM64_HAS_ECV_CNTPOFF,
2269 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2270 		.matches = has_cpuid_feature,
2271 		ARM64_CPUID_FIELDS(ID_AA64MMFR0_EL1, ECV, CNTPOFF)
2272 	},
2273 #ifdef CONFIG_ARM64_PAN
2274 	{
2275 		.desc = "Privileged Access Never",
2276 		.capability = ARM64_HAS_PAN,
2277 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2278 		.matches = has_cpuid_feature,
2279 		.cpu_enable = cpu_enable_pan,
2280 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, PAN, IMP)
2281 	},
2282 #endif /* CONFIG_ARM64_PAN */
2283 #ifdef CONFIG_ARM64_EPAN
2284 	{
2285 		.desc = "Enhanced Privileged Access Never",
2286 		.capability = ARM64_HAS_EPAN,
2287 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2288 		.matches = has_cpuid_feature,
2289 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, PAN, PAN3)
2290 	},
2291 #endif /* CONFIG_ARM64_EPAN */
2292 #ifdef CONFIG_ARM64_LSE_ATOMICS
2293 	{
2294 		.desc = "LSE atomic instructions",
2295 		.capability = ARM64_HAS_LSE_ATOMICS,
2296 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2297 		.matches = has_cpuid_feature,
2298 		ARM64_CPUID_FIELDS(ID_AA64ISAR0_EL1, ATOMIC, IMP)
2299 	},
2300 #endif /* CONFIG_ARM64_LSE_ATOMICS */
2301 	{
2302 		.desc = "Software prefetching using PRFM",
2303 		.capability = ARM64_HAS_NO_HW_PREFETCH,
2304 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2305 		.matches = has_no_hw_prefetch,
2306 	},
2307 	{
2308 		.desc = "Virtualization Host Extensions",
2309 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
2310 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2311 		.matches = runs_at_el2,
2312 		.cpu_enable = cpu_copy_el2regs,
2313 	},
2314 	{
2315 		.desc = "Nested Virtualization Support",
2316 		.capability = ARM64_HAS_NESTED_VIRT,
2317 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2318 		.matches = has_nested_virt_support,
2319 		ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, NV, IMP)
2320 	},
2321 	{
2322 		.capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE,
2323 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2324 		.matches = has_32bit_el0,
2325 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, EL0, AARCH32)
2326 	},
2327 #ifdef CONFIG_KVM
2328 	{
2329 		.desc = "32-bit EL1 Support",
2330 		.capability = ARM64_HAS_32BIT_EL1,
2331 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2332 		.matches = has_cpuid_feature,
2333 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, EL1, AARCH32)
2334 	},
2335 	{
2336 		.desc = "Protected KVM",
2337 		.capability = ARM64_KVM_PROTECTED_MODE,
2338 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2339 		.matches = is_kvm_protected_mode,
2340 	},
2341 	{
2342 		.desc = "HCRX_EL2 register",
2343 		.capability = ARM64_HAS_HCX,
2344 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2345 		.matches = has_cpuid_feature,
2346 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HCX, IMP)
2347 	},
2348 #endif
2349 	{
2350 		.desc = "Kernel page table isolation (KPTI)",
2351 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
2352 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
2353 		.cpu_enable = kpti_install_ng_mappings,
2354 		.matches = unmap_kernel_at_el0,
2355 		/*
2356 		 * The ID feature fields below are used to indicate that
2357 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
2358 		 * more details.
2359 		 */
2360 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, CSV3, IMP)
2361 	},
2362 	{
2363 		/* FP/SIMD is not implemented */
2364 		.capability = ARM64_HAS_NO_FPSIMD,
2365 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
2366 		.min_field_value = 0,
2367 		.matches = has_no_fpsimd,
2368 	},
2369 #ifdef CONFIG_ARM64_PMEM
2370 	{
2371 		.desc = "Data cache clean to Point of Persistence",
2372 		.capability = ARM64_HAS_DCPOP,
2373 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2374 		.matches = has_cpuid_feature,
2375 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, DPB, IMP)
2376 	},
2377 	{
2378 		.desc = "Data cache clean to Point of Deep Persistence",
2379 		.capability = ARM64_HAS_DCPODP,
2380 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2381 		.matches = has_cpuid_feature,
2382 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, DPB, DPB2)
2383 	},
2384 #endif
2385 #ifdef CONFIG_ARM64_SVE
2386 	{
2387 		.desc = "Scalable Vector Extension",
2388 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2389 		.capability = ARM64_SVE,
2390 		.cpu_enable = sve_kernel_enable,
2391 		.matches = has_cpuid_feature,
2392 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, SVE, IMP)
2393 	},
2394 #endif /* CONFIG_ARM64_SVE */
2395 #ifdef CONFIG_ARM64_RAS_EXTN
2396 	{
2397 		.desc = "RAS Extension Support",
2398 		.capability = ARM64_HAS_RAS_EXTN,
2399 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2400 		.matches = has_cpuid_feature,
2401 		.cpu_enable = cpu_clear_disr,
2402 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, IMP)
2403 	},
2404 #endif /* CONFIG_ARM64_RAS_EXTN */
2405 #ifdef CONFIG_ARM64_AMU_EXTN
2406 	{
2407 		/*
2408 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
2409 		 * Therefore, don't provide .desc as we don't want the detection
2410 		 * message to be shown until at least one CPU is detected to
2411 		 * support the feature.
2412 		 */
2413 		.capability = ARM64_HAS_AMU_EXTN,
2414 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2415 		.matches = has_amu,
2416 		.cpu_enable = cpu_amu_enable,
2417 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, AMU, IMP)
2418 	},
2419 #endif /* CONFIG_ARM64_AMU_EXTN */
2420 	{
2421 		.desc = "Data cache clean to the PoU not required for I/D coherence",
2422 		.capability = ARM64_HAS_CACHE_IDC,
2423 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2424 		.matches = has_cache_idc,
2425 		.cpu_enable = cpu_emulate_effective_ctr,
2426 	},
2427 	{
2428 		.desc = "Instruction cache invalidation not required for I/D coherence",
2429 		.capability = ARM64_HAS_CACHE_DIC,
2430 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2431 		.matches = has_cache_dic,
2432 	},
2433 	{
2434 		.desc = "Stage-2 Force Write-Back",
2435 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2436 		.capability = ARM64_HAS_STAGE2_FWB,
2437 		.matches = has_cpuid_feature,
2438 		ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, FWB, IMP)
2439 	},
2440 	{
2441 		.desc = "ARMv8.4 Translation Table Level",
2442 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2443 		.capability = ARM64_HAS_ARMv8_4_TTL,
2444 		.matches = has_cpuid_feature,
2445 		ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, TTL, IMP)
2446 	},
2447 	{
2448 		.desc = "TLB range maintenance instructions",
2449 		.capability = ARM64_HAS_TLB_RANGE,
2450 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2451 		.matches = has_cpuid_feature,
2452 		ARM64_CPUID_FIELDS(ID_AA64ISAR0_EL1, TLB, RANGE)
2453 	},
2454 #ifdef CONFIG_ARM64_HW_AFDBM
2455 	{
2456 		/*
2457 		 * Since we turn this on always, we don't want the user to
2458 		 * think that the feature is available when it may not be.
2459 		 * So hide the description.
2460 		 *
2461 		 * .desc = "Hardware pagetable Dirty Bit Management",
2462 		 *
2463 		 */
2464 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2465 		.capability = ARM64_HW_DBM,
2466 		.matches = has_hw_dbm,
2467 		.cpu_enable = cpu_enable_hw_dbm,
2468 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HAFDBS, DBM)
2469 	},
2470 #endif
2471 	{
2472 		.desc = "CRC32 instructions",
2473 		.capability = ARM64_HAS_CRC32,
2474 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2475 		.matches = has_cpuid_feature,
2476 		ARM64_CPUID_FIELDS(ID_AA64ISAR0_EL1, CRC32, IMP)
2477 	},
2478 	{
2479 		.desc = "Speculative Store Bypassing Safe (SSBS)",
2480 		.capability = ARM64_SSBS,
2481 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2482 		.matches = has_cpuid_feature,
2483 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, SSBS, IMP)
2484 	},
2485 #ifdef CONFIG_ARM64_CNP
2486 	{
2487 		.desc = "Common not Private translations",
2488 		.capability = ARM64_HAS_CNP,
2489 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2490 		.matches = has_useable_cnp,
2491 		.cpu_enable = cpu_enable_cnp,
2492 		ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, CnP, IMP)
2493 	},
2494 #endif
2495 	{
2496 		.desc = "Speculation barrier (SB)",
2497 		.capability = ARM64_HAS_SB,
2498 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2499 		.matches = has_cpuid_feature,
2500 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, SB, IMP)
2501 	},
2502 #ifdef CONFIG_ARM64_PTR_AUTH
2503 	{
2504 		.desc = "Address authentication (architected QARMA5 algorithm)",
2505 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA5,
2506 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2507 		.matches = has_address_auth_cpucap,
2508 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, APA, PAuth)
2509 	},
2510 	{
2511 		.desc = "Address authentication (architected QARMA3 algorithm)",
2512 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA3,
2513 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2514 		.matches = has_address_auth_cpucap,
2515 		ARM64_CPUID_FIELDS(ID_AA64ISAR2_EL1, APA3, PAuth)
2516 	},
2517 	{
2518 		.desc = "Address authentication (IMP DEF algorithm)",
2519 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2520 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2521 		.matches = has_address_auth_cpucap,
2522 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, API, PAuth)
2523 	},
2524 	{
2525 		.capability = ARM64_HAS_ADDRESS_AUTH,
2526 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2527 		.matches = has_address_auth_metacap,
2528 	},
2529 	{
2530 		.desc = "Generic authentication (architected QARMA5 algorithm)",
2531 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH_QARMA5,
2532 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2533 		.matches = has_cpuid_feature,
2534 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, GPA, IMP)
2535 	},
2536 	{
2537 		.desc = "Generic authentication (architected QARMA3 algorithm)",
2538 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH_QARMA3,
2539 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2540 		.matches = has_cpuid_feature,
2541 		ARM64_CPUID_FIELDS(ID_AA64ISAR2_EL1, GPA3, IMP)
2542 	},
2543 	{
2544 		.desc = "Generic authentication (IMP DEF algorithm)",
2545 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2546 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2547 		.matches = has_cpuid_feature,
2548 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, GPI, IMP)
2549 	},
2550 	{
2551 		.capability = ARM64_HAS_GENERIC_AUTH,
2552 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2553 		.matches = has_generic_auth,
2554 	},
2555 #endif /* CONFIG_ARM64_PTR_AUTH */
2556 #ifdef CONFIG_ARM64_PSEUDO_NMI
2557 	{
2558 		/*
2559 		 * Depends on having GICv3
2560 		 */
2561 		.desc = "IRQ priority masking",
2562 		.capability = ARM64_HAS_GIC_PRIO_MASKING,
2563 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2564 		.matches = can_use_gic_priorities,
2565 	},
2566 	{
2567 		/*
2568 		 * Depends on ARM64_HAS_GIC_PRIO_MASKING
2569 		 */
2570 		.capability = ARM64_HAS_GIC_PRIO_RELAXED_SYNC,
2571 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2572 		.matches = has_gic_prio_relaxed_sync,
2573 	},
2574 #endif
2575 #ifdef CONFIG_ARM64_E0PD
2576 	{
2577 		.desc = "E0PD",
2578 		.capability = ARM64_HAS_E0PD,
2579 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2580 		.cpu_enable = cpu_enable_e0pd,
2581 		.matches = has_cpuid_feature,
2582 		ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, E0PD, IMP)
2583 	},
2584 #endif
2585 	{
2586 		.desc = "Random Number Generator",
2587 		.capability = ARM64_HAS_RNG,
2588 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2589 		.matches = has_cpuid_feature,
2590 		ARM64_CPUID_FIELDS(ID_AA64ISAR0_EL1, RNDR, IMP)
2591 	},
2592 #ifdef CONFIG_ARM64_BTI
2593 	{
2594 		.desc = "Branch Target Identification",
2595 		.capability = ARM64_BTI,
2596 #ifdef CONFIG_ARM64_BTI_KERNEL
2597 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2598 #else
2599 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2600 #endif
2601 		.matches = has_cpuid_feature,
2602 		.cpu_enable = bti_enable,
2603 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, BT, IMP)
2604 	},
2605 #endif
2606 #ifdef CONFIG_ARM64_MTE
2607 	{
2608 		.desc = "Memory Tagging Extension",
2609 		.capability = ARM64_MTE,
2610 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2611 		.matches = has_cpuid_feature,
2612 		.cpu_enable = cpu_enable_mte,
2613 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, MTE, MTE2)
2614 	},
2615 	{
2616 		.desc = "Asymmetric MTE Tag Check Fault",
2617 		.capability = ARM64_MTE_ASYMM,
2618 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2619 		.matches = has_cpuid_feature,
2620 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, MTE, MTE3)
2621 	},
2622 #endif /* CONFIG_ARM64_MTE */
2623 	{
2624 		.desc = "RCpc load-acquire (LDAPR)",
2625 		.capability = ARM64_HAS_LDAPR,
2626 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2627 		.matches = has_cpuid_feature,
2628 		ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LRCPC, IMP)
2629 	},
2630 #ifdef CONFIG_ARM64_SME
2631 	{
2632 		.desc = "Scalable Matrix Extension",
2633 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2634 		.capability = ARM64_SME,
2635 		.matches = has_cpuid_feature,
2636 		.cpu_enable = sme_kernel_enable,
2637 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, SME, IMP)
2638 	},
2639 	/* FA64 should be sorted after the base SME capability */
2640 	{
2641 		.desc = "FA64",
2642 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2643 		.capability = ARM64_SME_FA64,
2644 		.matches = has_cpuid_feature,
2645 		.cpu_enable = fa64_kernel_enable,
2646 		ARM64_CPUID_FIELDS(ID_AA64SMFR0_EL1, FA64, IMP)
2647 	},
2648 	{
2649 		.desc = "SME2",
2650 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2651 		.capability = ARM64_SME2,
2652 		.matches = has_cpuid_feature,
2653 		.cpu_enable = sme2_kernel_enable,
2654 		ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, SME, SME2)
2655 	},
2656 #endif /* CONFIG_ARM64_SME */
2657 	{
2658 		.desc = "WFx with timeout",
2659 		.capability = ARM64_HAS_WFXT,
2660 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2661 		.matches = has_cpuid_feature,
2662 		ARM64_CPUID_FIELDS(ID_AA64ISAR2_EL1, WFxT, IMP)
2663 	},
2664 	{
2665 		.desc = "Trap EL0 IMPLEMENTATION DEFINED functionality",
2666 		.capability = ARM64_HAS_TIDCP1,
2667 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2668 		.matches = has_cpuid_feature,
2669 		.cpu_enable = cpu_trap_el0_impdef,
2670 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, TIDCP1, IMP)
2671 	},
2672 	{
2673 		.desc = "Data independent timing control (DIT)",
2674 		.capability = ARM64_HAS_DIT,
2675 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2676 		.matches = has_cpuid_feature,
2677 		.cpu_enable = cpu_enable_dit,
2678 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, DIT, IMP)
2679 	},
2680 	{
2681 		.desc = "Memory Copy and Memory Set instructions",
2682 		.capability = ARM64_HAS_MOPS,
2683 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2684 		.matches = has_cpuid_feature,
2685 		.cpu_enable = cpu_enable_mops,
2686 		ARM64_CPUID_FIELDS(ID_AA64ISAR2_EL1, MOPS, IMP)
2687 	},
2688 	{
2689 		.capability = ARM64_HAS_TCR2,
2690 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2691 		.matches = has_cpuid_feature,
2692 		ARM64_CPUID_FIELDS(ID_AA64MMFR3_EL1, TCRX, IMP)
2693 	},
2694 	{
2695 		.desc = "Stage-1 Permission Indirection Extension (S1PIE)",
2696 		.capability = ARM64_HAS_S1PIE,
2697 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2698 		.matches = has_cpuid_feature,
2699 		ARM64_CPUID_FIELDS(ID_AA64MMFR3_EL1, S1PIE, IMP)
2700 	},
2701 	{
2702 		.desc = "VHE for hypervisor only",
2703 		.capability = ARM64_KVM_HVHE,
2704 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2705 		.matches = hvhe_possible,
2706 	},
2707 	{
2708 		.desc = "Enhanced Virtualization Traps",
2709 		.capability = ARM64_HAS_EVT,
2710 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2711 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2712 		.sign = FTR_UNSIGNED,
2713 		.field_pos = ID_AA64MMFR2_EL1_EVT_SHIFT,
2714 		.field_width = 4,
2715 		.min_field_value = ID_AA64MMFR2_EL1_EVT_IMP,
2716 		.matches = has_cpuid_feature,
2717 	},
2718 	{},
2719 };
2720 
2721 #define HWCAP_CPUID_MATCH(reg, field, min_value)			\
2722 		.matches = has_user_cpuid_feature,			\
2723 		ARM64_CPUID_FIELDS(reg, field, min_value)
2724 
2725 #define __HWCAP_CAP(name, cap_type, cap)					\
2726 		.desc = name,							\
2727 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2728 		.hwcap_type = cap_type,						\
2729 		.hwcap = cap,							\
2730 
2731 #define HWCAP_CAP(reg, field, min_value, cap_type, cap)		\
2732 	{									\
2733 		__HWCAP_CAP(#cap, cap_type, cap)				\
2734 		HWCAP_CPUID_MATCH(reg, field, min_value) 		\
2735 	}
2736 
2737 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2738 	{									\
2739 		__HWCAP_CAP(#cap, cap_type, cap)				\
2740 		.matches = cpucap_multi_entry_cap_matches,			\
2741 		.match_list = list,						\
2742 	}
2743 
2744 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2745 	{									\
2746 		__HWCAP_CAP(#cap, cap_type, cap)				\
2747 		.matches = match,						\
2748 	}
2749 
2750 #ifdef CONFIG_ARM64_PTR_AUTH
2751 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2752 	{
2753 		HWCAP_CPUID_MATCH(ID_AA64ISAR1_EL1, APA, PAuth)
2754 	},
2755 	{
2756 		HWCAP_CPUID_MATCH(ID_AA64ISAR2_EL1, APA3, PAuth)
2757 	},
2758 	{
2759 		HWCAP_CPUID_MATCH(ID_AA64ISAR1_EL1, API, PAuth)
2760 	},
2761 	{},
2762 };
2763 
2764 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2765 	{
2766 		HWCAP_CPUID_MATCH(ID_AA64ISAR1_EL1, GPA, IMP)
2767 	},
2768 	{
2769 		HWCAP_CPUID_MATCH(ID_AA64ISAR2_EL1, GPA3, IMP)
2770 	},
2771 	{
2772 		HWCAP_CPUID_MATCH(ID_AA64ISAR1_EL1, GPI, IMP)
2773 	},
2774 	{},
2775 };
2776 #endif
2777 
2778 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2779 	HWCAP_CAP(ID_AA64ISAR0_EL1, AES, PMULL, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2780 	HWCAP_CAP(ID_AA64ISAR0_EL1, AES, AES, CAP_HWCAP, KERNEL_HWCAP_AES),
2781 	HWCAP_CAP(ID_AA64ISAR0_EL1, SHA1, IMP, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2782 	HWCAP_CAP(ID_AA64ISAR0_EL1, SHA2, SHA256, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2783 	HWCAP_CAP(ID_AA64ISAR0_EL1, SHA2, SHA512, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2784 	HWCAP_CAP(ID_AA64ISAR0_EL1, CRC32, IMP, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2785 	HWCAP_CAP(ID_AA64ISAR0_EL1, ATOMIC, IMP, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2786 	HWCAP_CAP(ID_AA64ISAR0_EL1, RDM, IMP, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2787 	HWCAP_CAP(ID_AA64ISAR0_EL1, SHA3, IMP, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2788 	HWCAP_CAP(ID_AA64ISAR0_EL1, SM3, IMP, CAP_HWCAP, KERNEL_HWCAP_SM3),
2789 	HWCAP_CAP(ID_AA64ISAR0_EL1, SM4, IMP, CAP_HWCAP, KERNEL_HWCAP_SM4),
2790 	HWCAP_CAP(ID_AA64ISAR0_EL1, DP, IMP, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2791 	HWCAP_CAP(ID_AA64ISAR0_EL1, FHM, IMP, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2792 	HWCAP_CAP(ID_AA64ISAR0_EL1, TS, FLAGM, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2793 	HWCAP_CAP(ID_AA64ISAR0_EL1, TS, FLAGM2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2794 	HWCAP_CAP(ID_AA64ISAR0_EL1, RNDR, IMP, CAP_HWCAP, KERNEL_HWCAP_RNG),
2795 	HWCAP_CAP(ID_AA64PFR0_EL1, FP, IMP, CAP_HWCAP, KERNEL_HWCAP_FP),
2796 	HWCAP_CAP(ID_AA64PFR0_EL1, FP, FP16, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2797 	HWCAP_CAP(ID_AA64PFR0_EL1, AdvSIMD, IMP, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2798 	HWCAP_CAP(ID_AA64PFR0_EL1, AdvSIMD, FP16, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2799 	HWCAP_CAP(ID_AA64PFR0_EL1, DIT, IMP, CAP_HWCAP, KERNEL_HWCAP_DIT),
2800 	HWCAP_CAP(ID_AA64ISAR1_EL1, DPB, IMP, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2801 	HWCAP_CAP(ID_AA64ISAR1_EL1, DPB, DPB2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2802 	HWCAP_CAP(ID_AA64ISAR1_EL1, JSCVT, IMP, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2803 	HWCAP_CAP(ID_AA64ISAR1_EL1, FCMA, IMP, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2804 	HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, IMP, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2805 	HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, LRCPC2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2806 	HWCAP_CAP(ID_AA64ISAR1_EL1, FRINTTS, IMP, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2807 	HWCAP_CAP(ID_AA64ISAR1_EL1, SB, IMP, CAP_HWCAP, KERNEL_HWCAP_SB),
2808 	HWCAP_CAP(ID_AA64ISAR1_EL1, BF16, IMP, CAP_HWCAP, KERNEL_HWCAP_BF16),
2809 	HWCAP_CAP(ID_AA64ISAR1_EL1, BF16, EBF16, CAP_HWCAP, KERNEL_HWCAP_EBF16),
2810 	HWCAP_CAP(ID_AA64ISAR1_EL1, DGH, IMP, CAP_HWCAP, KERNEL_HWCAP_DGH),
2811 	HWCAP_CAP(ID_AA64ISAR1_EL1, I8MM, IMP, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2812 	HWCAP_CAP(ID_AA64MMFR2_EL1, AT, IMP, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2813 #ifdef CONFIG_ARM64_SVE
2814 	HWCAP_CAP(ID_AA64PFR0_EL1, SVE, IMP, CAP_HWCAP, KERNEL_HWCAP_SVE),
2815 	HWCAP_CAP(ID_AA64ZFR0_EL1, SVEver, SVE2p1, CAP_HWCAP, KERNEL_HWCAP_SVE2P1),
2816 	HWCAP_CAP(ID_AA64ZFR0_EL1, SVEver, SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2817 	HWCAP_CAP(ID_AA64ZFR0_EL1, AES, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2818 	HWCAP_CAP(ID_AA64ZFR0_EL1, AES, PMULL128, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2819 	HWCAP_CAP(ID_AA64ZFR0_EL1, BitPerm, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2820 	HWCAP_CAP(ID_AA64ZFR0_EL1, BF16, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2821 	HWCAP_CAP(ID_AA64ZFR0_EL1, BF16, EBF16, CAP_HWCAP, KERNEL_HWCAP_SVE_EBF16),
2822 	HWCAP_CAP(ID_AA64ZFR0_EL1, SHA3, IMP, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2823 	HWCAP_CAP(ID_AA64ZFR0_EL1, SM4, IMP, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2824 	HWCAP_CAP(ID_AA64ZFR0_EL1, I8MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2825 	HWCAP_CAP(ID_AA64ZFR0_EL1, F32MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2826 	HWCAP_CAP(ID_AA64ZFR0_EL1, F64MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2827 #endif
2828 	HWCAP_CAP(ID_AA64PFR1_EL1, SSBS, SSBS2, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2829 #ifdef CONFIG_ARM64_BTI
2830 	HWCAP_CAP(ID_AA64PFR1_EL1, BT, IMP, CAP_HWCAP, KERNEL_HWCAP_BTI),
2831 #endif
2832 #ifdef CONFIG_ARM64_PTR_AUTH
2833 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2834 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2835 #endif
2836 #ifdef CONFIG_ARM64_MTE
2837 	HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE2, CAP_HWCAP, KERNEL_HWCAP_MTE),
2838 	HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE3, CAP_HWCAP, KERNEL_HWCAP_MTE3),
2839 #endif /* CONFIG_ARM64_MTE */
2840 	HWCAP_CAP(ID_AA64MMFR0_EL1, ECV, IMP, CAP_HWCAP, KERNEL_HWCAP_ECV),
2841 	HWCAP_CAP(ID_AA64MMFR1_EL1, AFP, IMP, CAP_HWCAP, KERNEL_HWCAP_AFP),
2842 	HWCAP_CAP(ID_AA64ISAR2_EL1, CSSC, IMP, CAP_HWCAP, KERNEL_HWCAP_CSSC),
2843 	HWCAP_CAP(ID_AA64ISAR2_EL1, RPRFM, IMP, CAP_HWCAP, KERNEL_HWCAP_RPRFM),
2844 	HWCAP_CAP(ID_AA64ISAR2_EL1, RPRES, IMP, CAP_HWCAP, KERNEL_HWCAP_RPRES),
2845 	HWCAP_CAP(ID_AA64ISAR2_EL1, WFxT, IMP, CAP_HWCAP, KERNEL_HWCAP_WFXT),
2846 	HWCAP_CAP(ID_AA64ISAR2_EL1, MOPS, IMP, CAP_HWCAP, KERNEL_HWCAP_MOPS),
2847 #ifdef CONFIG_ARM64_SME
2848 	HWCAP_CAP(ID_AA64PFR1_EL1, SME, IMP, CAP_HWCAP, KERNEL_HWCAP_SME),
2849 	HWCAP_CAP(ID_AA64SMFR0_EL1, FA64, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_FA64),
2850 	HWCAP_CAP(ID_AA64SMFR0_EL1, SMEver, SME2p1, CAP_HWCAP, KERNEL_HWCAP_SME2P1),
2851 	HWCAP_CAP(ID_AA64SMFR0_EL1, SMEver, SME2, CAP_HWCAP, KERNEL_HWCAP_SME2),
2852 	HWCAP_CAP(ID_AA64SMFR0_EL1, I16I64, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_I16I64),
2853 	HWCAP_CAP(ID_AA64SMFR0_EL1, F64F64, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_F64F64),
2854 	HWCAP_CAP(ID_AA64SMFR0_EL1, I16I32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_I16I32),
2855 	HWCAP_CAP(ID_AA64SMFR0_EL1, B16B16, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_B16B16),
2856 	HWCAP_CAP(ID_AA64SMFR0_EL1, F16F16, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_F16F16),
2857 	HWCAP_CAP(ID_AA64SMFR0_EL1, I8I32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_I8I32),
2858 	HWCAP_CAP(ID_AA64SMFR0_EL1, F16F32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_F16F32),
2859 	HWCAP_CAP(ID_AA64SMFR0_EL1, B16F32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_B16F32),
2860 	HWCAP_CAP(ID_AA64SMFR0_EL1, BI32I32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_BI32I32),
2861 	HWCAP_CAP(ID_AA64SMFR0_EL1, F32F32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_F32F32),
2862 #endif /* CONFIG_ARM64_SME */
2863 	{},
2864 };
2865 
2866 #ifdef CONFIG_COMPAT
2867 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2868 {
2869 	/*
2870 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2871 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2872 	 * check is future proof, by making sure value is non-zero.
2873 	 */
2874 	u32 mvfr1;
2875 
2876 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2877 	if (scope == SCOPE_SYSTEM)
2878 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2879 	else
2880 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2881 
2882 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_EL1_SIMDSP_SHIFT) &&
2883 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_EL1_SIMDInt_SHIFT) &&
2884 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_EL1_SIMDLS_SHIFT);
2885 }
2886 #endif
2887 
2888 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2889 #ifdef CONFIG_COMPAT
2890 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2891 	HWCAP_CAP(MVFR1_EL1, SIMDFMAC, IMP, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2892 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2893 	HWCAP_CAP(MVFR0_EL1, FPDP, VFPv3, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2894 	HWCAP_CAP(MVFR0_EL1, FPDP, VFPv3, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2895 	HWCAP_CAP(MVFR1_EL1, FPHP, FP16, CAP_COMPAT_HWCAP, COMPAT_HWCAP_FPHP),
2896 	HWCAP_CAP(MVFR1_EL1, SIMDHP, SIMDHP_FLOAT, CAP_COMPAT_HWCAP, COMPAT_HWCAP_ASIMDHP),
2897 	HWCAP_CAP(ID_ISAR5_EL1, AES, VMULL, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2898 	HWCAP_CAP(ID_ISAR5_EL1, AES, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2899 	HWCAP_CAP(ID_ISAR5_EL1, SHA1, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2900 	HWCAP_CAP(ID_ISAR5_EL1, SHA2, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2901 	HWCAP_CAP(ID_ISAR5_EL1, CRC32, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2902 	HWCAP_CAP(ID_ISAR6_EL1, DP, IMP, CAP_COMPAT_HWCAP, COMPAT_HWCAP_ASIMDDP),
2903 	HWCAP_CAP(ID_ISAR6_EL1, FHM, IMP, CAP_COMPAT_HWCAP, COMPAT_HWCAP_ASIMDFHM),
2904 	HWCAP_CAP(ID_ISAR6_EL1, SB, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SB),
2905 	HWCAP_CAP(ID_ISAR6_EL1, BF16, IMP, CAP_COMPAT_HWCAP, COMPAT_HWCAP_ASIMDBF16),
2906 	HWCAP_CAP(ID_ISAR6_EL1, I8MM, IMP, CAP_COMPAT_HWCAP, COMPAT_HWCAP_I8MM),
2907 	HWCAP_CAP(ID_PFR2_EL1, SSBS, IMP, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SSBS),
2908 #endif
2909 	{},
2910 };
2911 
2912 static void cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2913 {
2914 	switch (cap->hwcap_type) {
2915 	case CAP_HWCAP:
2916 		cpu_set_feature(cap->hwcap);
2917 		break;
2918 #ifdef CONFIG_COMPAT
2919 	case CAP_COMPAT_HWCAP:
2920 		compat_elf_hwcap |= (u32)cap->hwcap;
2921 		break;
2922 	case CAP_COMPAT_HWCAP2:
2923 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2924 		break;
2925 #endif
2926 	default:
2927 		WARN_ON(1);
2928 		break;
2929 	}
2930 }
2931 
2932 /* Check if we have a particular HWCAP enabled */
2933 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2934 {
2935 	bool rc;
2936 
2937 	switch (cap->hwcap_type) {
2938 	case CAP_HWCAP:
2939 		rc = cpu_have_feature(cap->hwcap);
2940 		break;
2941 #ifdef CONFIG_COMPAT
2942 	case CAP_COMPAT_HWCAP:
2943 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2944 		break;
2945 	case CAP_COMPAT_HWCAP2:
2946 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2947 		break;
2948 #endif
2949 	default:
2950 		WARN_ON(1);
2951 		rc = false;
2952 	}
2953 
2954 	return rc;
2955 }
2956 
2957 static void setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2958 {
2959 	/* We support emulation of accesses to CPU ID feature registers */
2960 	cpu_set_named_feature(CPUID);
2961 	for (; hwcaps->matches; hwcaps++)
2962 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2963 			cap_set_elf_hwcap(hwcaps);
2964 }
2965 
2966 static void update_cpu_capabilities(u16 scope_mask)
2967 {
2968 	int i;
2969 	const struct arm64_cpu_capabilities *caps;
2970 
2971 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2972 	for (i = 0; i < ARM64_NCAPS; i++) {
2973 		caps = cpucap_ptrs[i];
2974 		if (!caps || !(caps->type & scope_mask) ||
2975 		    cpus_have_cap(caps->capability) ||
2976 		    !caps->matches(caps, cpucap_default_scope(caps)))
2977 			continue;
2978 
2979 		if (caps->desc)
2980 			pr_info("detected: %s\n", caps->desc);
2981 
2982 		__set_bit(caps->capability, system_cpucaps);
2983 
2984 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2985 			set_bit(caps->capability, boot_cpucaps);
2986 	}
2987 }
2988 
2989 /*
2990  * Enable all the available capabilities on this CPU. The capabilities
2991  * with BOOT_CPU scope are handled separately and hence skipped here.
2992  */
2993 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2994 {
2995 	int i;
2996 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2997 
2998 	for_each_available_cap(i) {
2999 		const struct arm64_cpu_capabilities *cap = cpucap_ptrs[i];
3000 
3001 		if (WARN_ON(!cap))
3002 			continue;
3003 
3004 		if (!(cap->type & non_boot_scope))
3005 			continue;
3006 
3007 		if (cap->cpu_enable)
3008 			cap->cpu_enable(cap);
3009 	}
3010 	return 0;
3011 }
3012 
3013 /*
3014  * Run through the enabled capabilities and enable() it on all active
3015  * CPUs
3016  */
3017 static void __init enable_cpu_capabilities(u16 scope_mask)
3018 {
3019 	int i;
3020 	const struct arm64_cpu_capabilities *caps;
3021 	bool boot_scope;
3022 
3023 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
3024 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
3025 
3026 	for (i = 0; i < ARM64_NCAPS; i++) {
3027 		unsigned int num;
3028 
3029 		caps = cpucap_ptrs[i];
3030 		if (!caps || !(caps->type & scope_mask))
3031 			continue;
3032 		num = caps->capability;
3033 		if (!cpus_have_cap(num))
3034 			continue;
3035 
3036 		if (boot_scope && caps->cpu_enable)
3037 			/*
3038 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
3039 			 * before any secondary CPU boots. Thus, each secondary
3040 			 * will enable the capability as appropriate via
3041 			 * check_local_cpu_capabilities(). The only exception is
3042 			 * the boot CPU, for which the capability must be
3043 			 * enabled here. This approach avoids costly
3044 			 * stop_machine() calls for this case.
3045 			 */
3046 			caps->cpu_enable(caps);
3047 	}
3048 
3049 	/*
3050 	 * For all non-boot scope capabilities, use stop_machine()
3051 	 * as it schedules the work allowing us to modify PSTATE,
3052 	 * instead of on_each_cpu() which uses an IPI, giving us a
3053 	 * PSTATE that disappears when we return.
3054 	 */
3055 	if (!boot_scope)
3056 		stop_machine(cpu_enable_non_boot_scope_capabilities,
3057 			     NULL, cpu_online_mask);
3058 }
3059 
3060 /*
3061  * Run through the list of capabilities to check for conflicts.
3062  * If the system has already detected a capability, take necessary
3063  * action on this CPU.
3064  */
3065 static void verify_local_cpu_caps(u16 scope_mask)
3066 {
3067 	int i;
3068 	bool cpu_has_cap, system_has_cap;
3069 	const struct arm64_cpu_capabilities *caps;
3070 
3071 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
3072 
3073 	for (i = 0; i < ARM64_NCAPS; i++) {
3074 		caps = cpucap_ptrs[i];
3075 		if (!caps || !(caps->type & scope_mask))
3076 			continue;
3077 
3078 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
3079 		system_has_cap = cpus_have_cap(caps->capability);
3080 
3081 		if (system_has_cap) {
3082 			/*
3083 			 * Check if the new CPU misses an advertised feature,
3084 			 * which is not safe to miss.
3085 			 */
3086 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
3087 				break;
3088 			/*
3089 			 * We have to issue cpu_enable() irrespective of
3090 			 * whether the CPU has it or not, as it is enabeld
3091 			 * system wide. It is upto the call back to take
3092 			 * appropriate action on this CPU.
3093 			 */
3094 			if (caps->cpu_enable)
3095 				caps->cpu_enable(caps);
3096 		} else {
3097 			/*
3098 			 * Check if the CPU has this capability if it isn't
3099 			 * safe to have when the system doesn't.
3100 			 */
3101 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
3102 				break;
3103 		}
3104 	}
3105 
3106 	if (i < ARM64_NCAPS) {
3107 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
3108 			smp_processor_id(), caps->capability,
3109 			caps->desc, system_has_cap, cpu_has_cap);
3110 
3111 		if (cpucap_panic_on_conflict(caps))
3112 			cpu_panic_kernel();
3113 		else
3114 			cpu_die_early();
3115 	}
3116 }
3117 
3118 /*
3119  * Check for CPU features that are used in early boot
3120  * based on the Boot CPU value.
3121  */
3122 static void check_early_cpu_features(void)
3123 {
3124 	verify_cpu_asid_bits();
3125 
3126 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
3127 }
3128 
3129 static void
3130 __verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
3131 {
3132 
3133 	for (; caps->matches; caps++)
3134 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
3135 			pr_crit("CPU%d: missing HWCAP: %s\n",
3136 					smp_processor_id(), caps->desc);
3137 			cpu_die_early();
3138 		}
3139 }
3140 
3141 static void verify_local_elf_hwcaps(void)
3142 {
3143 	__verify_local_elf_hwcaps(arm64_elf_hwcaps);
3144 
3145 	if (id_aa64pfr0_32bit_el0(read_cpuid(ID_AA64PFR0_EL1)))
3146 		__verify_local_elf_hwcaps(compat_elf_hwcaps);
3147 }
3148 
3149 static void verify_sve_features(void)
3150 {
3151 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
3152 	u64 zcr = read_zcr_features();
3153 
3154 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
3155 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
3156 
3157 	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SVE)) {
3158 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
3159 			smp_processor_id());
3160 		cpu_die_early();
3161 	}
3162 
3163 	/* Add checks on other ZCR bits here if necessary */
3164 }
3165 
3166 static void verify_sme_features(void)
3167 {
3168 	u64 safe_smcr = read_sanitised_ftr_reg(SYS_SMCR_EL1);
3169 	u64 smcr = read_smcr_features();
3170 
3171 	unsigned int safe_len = safe_smcr & SMCR_ELx_LEN_MASK;
3172 	unsigned int len = smcr & SMCR_ELx_LEN_MASK;
3173 
3174 	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SME)) {
3175 		pr_crit("CPU%d: SME: vector length support mismatch\n",
3176 			smp_processor_id());
3177 		cpu_die_early();
3178 	}
3179 
3180 	/* Add checks on other SMCR bits here if necessary */
3181 }
3182 
3183 static void verify_hyp_capabilities(void)
3184 {
3185 	u64 safe_mmfr1, mmfr0, mmfr1;
3186 	int parange, ipa_max;
3187 	unsigned int safe_vmid_bits, vmid_bits;
3188 
3189 	if (!IS_ENABLED(CONFIG_KVM))
3190 		return;
3191 
3192 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
3193 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
3194 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
3195 
3196 	/* Verify VMID bits */
3197 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
3198 	vmid_bits = get_vmid_bits(mmfr1);
3199 	if (vmid_bits < safe_vmid_bits) {
3200 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
3201 		cpu_die_early();
3202 	}
3203 
3204 	/* Verify IPA range */
3205 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
3206 				ID_AA64MMFR0_EL1_PARANGE_SHIFT);
3207 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
3208 	if (ipa_max < get_kvm_ipa_limit()) {
3209 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
3210 		cpu_die_early();
3211 	}
3212 }
3213 
3214 /*
3215  * Run through the enabled system capabilities and enable() it on this CPU.
3216  * The capabilities were decided based on the available CPUs at the boot time.
3217  * Any new CPU should match the system wide status of the capability. If the
3218  * new CPU doesn't have a capability which the system now has enabled, we
3219  * cannot do anything to fix it up and could cause unexpected failures. So
3220  * we park the CPU.
3221  */
3222 static void verify_local_cpu_capabilities(void)
3223 {
3224 	/*
3225 	 * The capabilities with SCOPE_BOOT_CPU are checked from
3226 	 * check_early_cpu_features(), as they need to be verified
3227 	 * on all secondary CPUs.
3228 	 */
3229 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
3230 	verify_local_elf_hwcaps();
3231 
3232 	if (system_supports_sve())
3233 		verify_sve_features();
3234 
3235 	if (system_supports_sme())
3236 		verify_sme_features();
3237 
3238 	if (is_hyp_mode_available())
3239 		verify_hyp_capabilities();
3240 }
3241 
3242 void check_local_cpu_capabilities(void)
3243 {
3244 	/*
3245 	 * All secondary CPUs should conform to the early CPU features
3246 	 * in use by the kernel based on boot CPU.
3247 	 */
3248 	check_early_cpu_features();
3249 
3250 	/*
3251 	 * If we haven't finalised the system capabilities, this CPU gets
3252 	 * a chance to update the errata work arounds and local features.
3253 	 * Otherwise, this CPU should verify that it has all the system
3254 	 * advertised capabilities.
3255 	 */
3256 	if (!system_capabilities_finalized())
3257 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
3258 	else
3259 		verify_local_cpu_capabilities();
3260 }
3261 
3262 static void __init setup_boot_cpu_capabilities(void)
3263 {
3264 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
3265 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
3266 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
3267 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
3268 }
3269 
3270 bool this_cpu_has_cap(unsigned int n)
3271 {
3272 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
3273 		const struct arm64_cpu_capabilities *cap = cpucap_ptrs[n];
3274 
3275 		if (cap)
3276 			return cap->matches(cap, SCOPE_LOCAL_CPU);
3277 	}
3278 
3279 	return false;
3280 }
3281 EXPORT_SYMBOL_GPL(this_cpu_has_cap);
3282 
3283 /*
3284  * This helper function is used in a narrow window when,
3285  * - The system wide safe registers are set with all the SMP CPUs and,
3286  * - The SYSTEM_FEATURE system_cpucaps may not have been set.
3287  * In all other cases cpus_have_{const_}cap() should be used.
3288  */
3289 static bool __maybe_unused __system_matches_cap(unsigned int n)
3290 {
3291 	if (n < ARM64_NCAPS) {
3292 		const struct arm64_cpu_capabilities *cap = cpucap_ptrs[n];
3293 
3294 		if (cap)
3295 			return cap->matches(cap, SCOPE_SYSTEM);
3296 	}
3297 	return false;
3298 }
3299 
3300 void cpu_set_feature(unsigned int num)
3301 {
3302 	set_bit(num, elf_hwcap);
3303 }
3304 
3305 bool cpu_have_feature(unsigned int num)
3306 {
3307 	return test_bit(num, elf_hwcap);
3308 }
3309 EXPORT_SYMBOL_GPL(cpu_have_feature);
3310 
3311 unsigned long cpu_get_elf_hwcap(void)
3312 {
3313 	/*
3314 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
3315 	 * note that for userspace compatibility we guarantee that bits 62
3316 	 * and 63 will always be returned as 0.
3317 	 */
3318 	return elf_hwcap[0];
3319 }
3320 
3321 unsigned long cpu_get_elf_hwcap2(void)
3322 {
3323 	return elf_hwcap[1];
3324 }
3325 
3326 static void __init setup_system_capabilities(void)
3327 {
3328 	/*
3329 	 * We have finalised the system-wide safe feature
3330 	 * registers, finalise the capabilities that depend
3331 	 * on it. Also enable all the available capabilities,
3332 	 * that are not enabled already.
3333 	 */
3334 	update_cpu_capabilities(SCOPE_SYSTEM);
3335 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
3336 }
3337 
3338 void __init setup_cpu_features(void)
3339 {
3340 	u32 cwg;
3341 
3342 	setup_system_capabilities();
3343 	setup_elf_hwcaps(arm64_elf_hwcaps);
3344 
3345 	if (system_supports_32bit_el0()) {
3346 		setup_elf_hwcaps(compat_elf_hwcaps);
3347 		elf_hwcap_fixup();
3348 	}
3349 
3350 	if (system_uses_ttbr0_pan())
3351 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
3352 
3353 	sve_setup();
3354 	sme_setup();
3355 	minsigstksz_setup();
3356 
3357 	/*
3358 	 * Check for sane CTR_EL0.CWG value.
3359 	 */
3360 	cwg = cache_type_cwg();
3361 	if (!cwg)
3362 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
3363 			ARCH_DMA_MINALIGN);
3364 }
3365 
3366 static int enable_mismatched_32bit_el0(unsigned int cpu)
3367 {
3368 	/*
3369 	 * The first 32-bit-capable CPU we detected and so can no longer
3370 	 * be offlined by userspace. -1 indicates we haven't yet onlined
3371 	 * a 32-bit-capable CPU.
3372 	 */
3373 	static int lucky_winner = -1;
3374 
3375 	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
3376 	bool cpu_32bit = id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0);
3377 
3378 	if (cpu_32bit) {
3379 		cpumask_set_cpu(cpu, cpu_32bit_el0_mask);
3380 		static_branch_enable_cpuslocked(&arm64_mismatched_32bit_el0);
3381 	}
3382 
3383 	if (cpumask_test_cpu(0, cpu_32bit_el0_mask) == cpu_32bit)
3384 		return 0;
3385 
3386 	if (lucky_winner >= 0)
3387 		return 0;
3388 
3389 	/*
3390 	 * We've detected a mismatch. We need to keep one of our CPUs with
3391 	 * 32-bit EL0 online so that is_cpu_allowed() doesn't end up rejecting
3392 	 * every CPU in the system for a 32-bit task.
3393 	 */
3394 	lucky_winner = cpu_32bit ? cpu : cpumask_any_and(cpu_32bit_el0_mask,
3395 							 cpu_active_mask);
3396 	get_cpu_device(lucky_winner)->offline_disabled = true;
3397 	setup_elf_hwcaps(compat_elf_hwcaps);
3398 	elf_hwcap_fixup();
3399 	pr_info("Asymmetric 32-bit EL0 support detected on CPU %u; CPU hot-unplug disabled on CPU %u\n",
3400 		cpu, lucky_winner);
3401 	return 0;
3402 }
3403 
3404 static int __init init_32bit_el0_mask(void)
3405 {
3406 	if (!allow_mismatched_32bit_el0)
3407 		return 0;
3408 
3409 	if (!zalloc_cpumask_var(&cpu_32bit_el0_mask, GFP_KERNEL))
3410 		return -ENOMEM;
3411 
3412 	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
3413 				 "arm64/mismatched_32bit_el0:online",
3414 				 enable_mismatched_32bit_el0, NULL);
3415 }
3416 subsys_initcall_sync(init_32bit_el0_mask);
3417 
3418 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
3419 {
3420 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
3421 }
3422 
3423 /*
3424  * We emulate only the following system register space.
3425  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 2 - 7]
3426  * See Table C5-6 System instruction encodings for System register accesses,
3427  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
3428  */
3429 static inline bool __attribute_const__ is_emulated(u32 id)
3430 {
3431 	return (sys_reg_Op0(id) == 0x3 &&
3432 		sys_reg_CRn(id) == 0x0 &&
3433 		sys_reg_Op1(id) == 0x0 &&
3434 		(sys_reg_CRm(id) == 0 ||
3435 		 ((sys_reg_CRm(id) >= 2) && (sys_reg_CRm(id) <= 7))));
3436 }
3437 
3438 /*
3439  * With CRm == 0, reg should be one of :
3440  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
3441  */
3442 static inline int emulate_id_reg(u32 id, u64 *valp)
3443 {
3444 	switch (id) {
3445 	case SYS_MIDR_EL1:
3446 		*valp = read_cpuid_id();
3447 		break;
3448 	case SYS_MPIDR_EL1:
3449 		*valp = SYS_MPIDR_SAFE_VAL;
3450 		break;
3451 	case SYS_REVIDR_EL1:
3452 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
3453 		*valp = 0;
3454 		break;
3455 	default:
3456 		return -EINVAL;
3457 	}
3458 
3459 	return 0;
3460 }
3461 
3462 static int emulate_sys_reg(u32 id, u64 *valp)
3463 {
3464 	struct arm64_ftr_reg *regp;
3465 
3466 	if (!is_emulated(id))
3467 		return -EINVAL;
3468 
3469 	if (sys_reg_CRm(id) == 0)
3470 		return emulate_id_reg(id, valp);
3471 
3472 	regp = get_arm64_ftr_reg_nowarn(id);
3473 	if (regp)
3474 		*valp = arm64_ftr_reg_user_value(regp);
3475 	else
3476 		/*
3477 		 * The untracked registers are either IMPLEMENTATION DEFINED
3478 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
3479 		 */
3480 		*valp = 0;
3481 	return 0;
3482 }
3483 
3484 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
3485 {
3486 	int rc;
3487 	u64 val;
3488 
3489 	rc = emulate_sys_reg(sys_reg, &val);
3490 	if (!rc) {
3491 		pt_regs_write_reg(regs, rt, val);
3492 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
3493 	}
3494 	return rc;
3495 }
3496 
3497 bool try_emulate_mrs(struct pt_regs *regs, u32 insn)
3498 {
3499 	u32 sys_reg, rt;
3500 
3501 	if (compat_user_mode(regs) || !aarch64_insn_is_mrs(insn))
3502 		return false;
3503 
3504 	/*
3505 	 * sys_reg values are defined as used in mrs/msr instruction.
3506 	 * shift the imm value to get the encoding.
3507 	 */
3508 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
3509 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
3510 	return do_emulate_mrs(regs, sys_reg, rt) == 0;
3511 }
3512 
3513 enum mitigation_state arm64_get_meltdown_state(void)
3514 {
3515 	if (__meltdown_safe)
3516 		return SPECTRE_UNAFFECTED;
3517 
3518 	if (arm64_kernel_unmapped_at_el0())
3519 		return SPECTRE_MITIGATED;
3520 
3521 	return SPECTRE_VULNERABLE;
3522 }
3523 
3524 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
3525 			  char *buf)
3526 {
3527 	switch (arm64_get_meltdown_state()) {
3528 	case SPECTRE_UNAFFECTED:
3529 		return sprintf(buf, "Not affected\n");
3530 
3531 	case SPECTRE_MITIGATED:
3532 		return sprintf(buf, "Mitigation: PTI\n");
3533 
3534 	default:
3535 		return sprintf(buf, "Vulnerable\n");
3536 	}
3537 }
3538