xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision be801411)
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/sort.h>
69 #include <linux/stop_machine.h>
70 #include <linux/sysfs.h>
71 #include <linux/types.h>
72 #include <linux/minmax.h>
73 #include <linux/mm.h>
74 #include <linux/cpu.h>
75 #include <linux/kasan.h>
76 #include <linux/percpu.h>
77 
78 #include <asm/cpu.h>
79 #include <asm/cpufeature.h>
80 #include <asm/cpu_ops.h>
81 #include <asm/fpsimd.h>
82 #include <asm/insn.h>
83 #include <asm/kvm_host.h>
84 #include <asm/mmu_context.h>
85 #include <asm/mte.h>
86 #include <asm/processor.h>
87 #include <asm/smp.h>
88 #include <asm/sysreg.h>
89 #include <asm/traps.h>
90 #include <asm/vectors.h>
91 #include <asm/virt.h>
92 
93 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
94 static unsigned long elf_hwcap __read_mostly;
95 
96 #ifdef CONFIG_COMPAT
97 #define COMPAT_ELF_HWCAP_DEFAULT	\
98 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
99 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
100 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\
101 				 COMPAT_HWCAP_LPAE)
102 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
103 unsigned int compat_elf_hwcap2 __read_mostly;
104 #endif
105 
106 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
107 EXPORT_SYMBOL(cpu_hwcaps);
108 static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
109 
110 /* Need also bit for ARM64_CB_PATCH */
111 DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
112 
113 bool arm64_use_ng_mappings = false;
114 EXPORT_SYMBOL(arm64_use_ng_mappings);
115 
116 DEFINE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector) = vectors;
117 
118 /*
119  * Permit PER_LINUX32 and execve() of 32-bit binaries even if not all CPUs
120  * support it?
121  */
122 static bool __read_mostly allow_mismatched_32bit_el0;
123 
124 /*
125  * Static branch enabled only if allow_mismatched_32bit_el0 is set and we have
126  * seen at least one CPU capable of 32-bit EL0.
127  */
128 DEFINE_STATIC_KEY_FALSE(arm64_mismatched_32bit_el0);
129 
130 /*
131  * Mask of CPUs supporting 32-bit EL0.
132  * Only valid if arm64_mismatched_32bit_el0 is enabled.
133  */
134 static cpumask_var_t cpu_32bit_el0_mask __cpumask_var_read_mostly;
135 
136 /*
137  * Flag to indicate if we have computed the system wide
138  * capabilities based on the boot time active CPUs. This
139  * will be used to determine if a new booting CPU should
140  * go through the verification process to make sure that it
141  * supports the system capabilities, without using a hotplug
142  * notifier. This is also used to decide if we could use
143  * the fast path for checking constant CPU caps.
144  */
145 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
146 EXPORT_SYMBOL(arm64_const_caps_ready);
147 static inline void finalize_system_capabilities(void)
148 {
149 	static_branch_enable(&arm64_const_caps_ready);
150 }
151 
152 void dump_cpu_features(void)
153 {
154 	/* file-wide pr_fmt adds "CPU features: " prefix */
155 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
156 }
157 
158 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
159 EXPORT_SYMBOL(cpu_hwcap_keys);
160 
161 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
162 	{						\
163 		.sign = SIGNED,				\
164 		.visible = VISIBLE,			\
165 		.strict = STRICT,			\
166 		.type = TYPE,				\
167 		.shift = SHIFT,				\
168 		.width = WIDTH,				\
169 		.safe_val = SAFE_VAL,			\
170 	}
171 
172 /* Define a feature with unsigned values */
173 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
174 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
175 
176 /* Define a feature with a signed value */
177 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
178 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
179 
180 #define ARM64_FTR_END					\
181 	{						\
182 		.width = 0,				\
183 	}
184 
185 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
186 
187 static bool __system_matches_cap(unsigned int n);
188 
189 /*
190  * NOTE: Any changes to the visibility of features should be kept in
191  * sync with the documentation of the CPU feature register ABI.
192  */
193 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
194 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_RNDR_SHIFT, 4, 0),
195 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_TLB_SHIFT, 4, 0),
196 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_TS_SHIFT, 4, 0),
197 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_FHM_SHIFT, 4, 0),
198 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_DP_SHIFT, 4, 0),
199 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SM4_SHIFT, 4, 0),
200 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SM3_SHIFT, 4, 0),
201 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA3_SHIFT, 4, 0),
202 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_RDM_SHIFT, 4, 0),
203 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_ATOMIC_SHIFT, 4, 0),
204 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_CRC32_SHIFT, 4, 0),
205 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA2_SHIFT, 4, 0),
206 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_SHA1_SHIFT, 4, 0),
207 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_EL1_AES_SHIFT, 4, 0),
208 	ARM64_FTR_END,
209 };
210 
211 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
212 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
213 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DGH_SHIFT, 4, 0),
214 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_BF16_SHIFT, 4, 0),
215 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SPECRES_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
217 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
218 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
219 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
220 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
221 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
222 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
223 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
224 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
225 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
226 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_API_SHIFT, 4, 0),
227 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
228 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_APA_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
230 	ARM64_FTR_END,
231 };
232 
233 static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
234 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_CLEARBHB_SHIFT, 4, 0),
235 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
236 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_APA3_SHIFT, 4, 0),
237 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
238 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_GPA3_SHIFT, 4, 0),
239 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_RPRES_SHIFT, 4, 0),
240 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_WFXT_SHIFT, 4, 0),
241 	ARM64_FTR_END,
242 };
243 
244 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
245 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
246 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
247 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
248 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_AMU_SHIFT, 4, 0),
249 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_MPAM_SHIFT, 4, 0),
250 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SEL2_SHIFT, 4, 0),
251 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
252 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
253 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
254 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
255 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
256 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
257 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
258 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
259 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_ELx_64BIT_ONLY),
260 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_ELx_64BIT_ONLY),
261 	ARM64_FTR_END,
262 };
263 
264 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
265 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
266 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SME_SHIFT, 4, 0),
267 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
268 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
269 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
270 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MTE_SHIFT, 4, ID_AA64PFR1_MTE_NI),
271 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
272 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
273 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
274 	ARM64_FTR_END,
275 };
276 
277 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
278 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
279 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
280 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
281 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
282 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
283 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
284 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
285 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
286 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
287 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
288 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
289 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BF16_SHIFT, 4, 0),
290 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
291 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
292 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
293 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
294 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
295 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
296 	ARM64_FTR_END,
297 };
298 
299 static const struct arm64_ftr_bits ftr_id_aa64smfr0[] = {
300 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
301 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_FA64_SHIFT, 1, 0),
302 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
303 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_I16I64_SHIFT, 4, 0),
304 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
305 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F64F64_SHIFT, 1, 0),
306 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
307 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_I8I32_SHIFT, 4, 0),
308 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
309 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F16F32_SHIFT, 1, 0),
310 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
311 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_B16F32_SHIFT, 1, 0),
312 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
313 		       FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F32F32_SHIFT, 1, 0),
314 	ARM64_FTR_END,
315 };
316 
317 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
318 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0),
319 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0),
320 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EXS_SHIFT, 4, 0),
321 	/*
322 	 * Page size not being supported at Stage-2 is not fatal. You
323 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
324 	 * your favourite nesting hypervisor.
325 	 *
326 	 * There is a small corner case where the hypervisor explicitly
327 	 * advertises a given granule size at Stage-2 (value 2) on some
328 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
329 	 * vCPUs. Although this is not forbidden by the architecture, it
330 	 * indicates that the hypervisor is being silly (or buggy).
331 	 *
332 	 * We make no effort to cope with this and pretend that if these
333 	 * fields are inconsistent across vCPUs, then it isn't worth
334 	 * trying to bring KVM up.
335 	 */
336 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
337 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
338 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
339 	/*
340 	 * We already refuse to boot CPUs that don't support our configured
341 	 * page size, so we can only detect mismatches for a page size other
342 	 * than the one we're currently using. Unfortunately, SoCs like this
343 	 * exist in the wild so, even though we don't like it, we'll have to go
344 	 * along with it and treat them as non-strict.
345 	 */
346 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
347 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
348 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
349 
350 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
351 	/* Linux shouldn't care about secure memory */
352 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
353 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
354 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
355 	/*
356 	 * Differing PARange is fine as long as all peripherals and memory are mapped
357 	 * within the minimum PARange of all CPUs
358 	 */
359 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
360 	ARM64_FTR_END,
361 };
362 
363 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
364 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_AFP_SHIFT, 4, 0),
365 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_ETS_SHIFT, 4, 0),
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_TWED_SHIFT, 4, 0),
367 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_XNX_SHIFT, 4, 0),
368 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64MMFR1_SPECSEI_SHIFT, 4, 0),
369 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
370 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
371 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
372 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
373 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
374 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
375 	ARM64_FTR_END,
376 };
377 
378 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
379 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0),
380 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EVT_SHIFT, 4, 0),
381 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_BBM_SHIFT, 4, 0),
382 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0),
383 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
384 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IDS_SHIFT, 4, 0),
385 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
386 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_ST_SHIFT, 4, 0),
387 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_NV_SHIFT, 4, 0),
388 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CCIDX_SHIFT, 4, 0),
389 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
390 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
391 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
392 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
393 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
394 	ARM64_FTR_END,
395 };
396 
397 static const struct arm64_ftr_bits ftr_ctr[] = {
398 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
399 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
400 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
401 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
402 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
403 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
404 	/*
405 	 * Linux can handle differing I-cache policies. Userspace JITs will
406 	 * make use of *minLine.
407 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
408 	 */
409 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, CTR_L1IP_SHIFT, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
410 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
411 	ARM64_FTR_END,
412 };
413 
414 static struct arm64_ftr_override __ro_after_init no_override = { };
415 
416 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
417 	.name		= "SYS_CTR_EL0",
418 	.ftr_bits	= ftr_ctr,
419 	.override	= &no_override,
420 };
421 
422 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
423 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_INNERSHR_SHIFT, 4, 0xf),
424 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_FCSE_SHIFT, 4, 0),
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_AUXREG_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_TCM_SHIFT, 4, 0),
427 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_SHARELVL_SHIFT, 4, 0),
428 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_OUTERSHR_SHIFT, 4, 0xf),
429 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_PMSA_SHIFT, 4, 0),
430 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_VMSA_SHIFT, 4, 0),
431 	ARM64_FTR_END,
432 };
433 
434 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
435 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_DOUBLELOCK_SHIFT, 4, 0),
436 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
437 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
438 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
439 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
440 	/*
441 	 * We can instantiate multiple PMU instances with different levels
442 	 * of support.
443 	 */
444 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
446 	ARM64_FTR_END,
447 };
448 
449 static const struct arm64_ftr_bits ftr_mvfr2[] = {
450 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_FPMISC_SHIFT, 4, 0),
451 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_SIMDMISC_SHIFT, 4, 0),
452 	ARM64_FTR_END,
453 };
454 
455 static const struct arm64_ftr_bits ftr_dczid[] = {
456 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_DZP_SHIFT, 1, 1),
457 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_BS_SHIFT, 4, 0),
458 	ARM64_FTR_END,
459 };
460 
461 static const struct arm64_ftr_bits ftr_gmid[] = {
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, SYS_GMID_EL1_BS_SHIFT, 4, 0),
463 	ARM64_FTR_END,
464 };
465 
466 static const struct arm64_ftr_bits ftr_id_isar0[] = {
467 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
468 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
469 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
470 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
471 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
472 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
474 	ARM64_FTR_END,
475 };
476 
477 static const struct arm64_ftr_bits ftr_id_isar5[] = {
478 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
479 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
480 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
481 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
484 	ARM64_FTR_END,
485 };
486 
487 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
488 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
489 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
490 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
491 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
492 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
493 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
494 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_AC2_SHIFT, 4, 0),
495 
496 	/*
497 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
498 	 * external abort on speculative read. It is safe to assume that an
499 	 * SError might be generated than it will not be. Hence it has been
500 	 * classified as FTR_HIGHER_SAFE.
501 	 */
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
503 	ARM64_FTR_END,
504 };
505 
506 static const struct arm64_ftr_bits ftr_id_isar4[] = {
507 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
508 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
509 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
510 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
511 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
512 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
513 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
514 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
515 	ARM64_FTR_END,
516 };
517 
518 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
519 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
520 	ARM64_FTR_END,
521 };
522 
523 static const struct arm64_ftr_bits ftr_id_isar6[] = {
524 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
525 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
526 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
527 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
531 	ARM64_FTR_END,
532 };
533 
534 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
535 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
536 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
537 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE3_SHIFT, 4, 0),
538 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE2_SHIFT, 4, 0),
539 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE1_SHIFT, 4, 0),
540 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE0_SHIFT, 4, 0),
541 	ARM64_FTR_END,
542 };
543 
544 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
545 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
546 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
547 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
548 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
549 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
550 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
551 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
552 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
553 	ARM64_FTR_END,
554 };
555 
556 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
557 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
558 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
559 	ARM64_FTR_END,
560 };
561 
562 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
563 	/* [31:28] TraceFilt */
564 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_PERFMON_SHIFT, 4, 0xf),
565 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MPROFDBG_SHIFT, 4, 0),
566 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPTRC_SHIFT, 4, 0),
567 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPTRC_SHIFT, 4, 0),
568 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPDBG_SHIFT, 4, 0),
569 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPSDBG_SHIFT, 4, 0),
570 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPDBG_SHIFT, 4, 0),
571 	ARM64_FTR_END,
572 };
573 
574 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
575 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
576 	ARM64_FTR_END,
577 };
578 
579 static const struct arm64_ftr_bits ftr_zcr[] = {
580 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
581 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_WIDTH, 0),	/* LEN */
582 	ARM64_FTR_END,
583 };
584 
585 static const struct arm64_ftr_bits ftr_smcr[] = {
586 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
587 		SMCR_ELx_LEN_SHIFT, SMCR_ELx_LEN_WIDTH, 0),	/* LEN */
588 	ARM64_FTR_END,
589 };
590 
591 /*
592  * Common ftr bits for a 32bit register with all hidden, strict
593  * attributes, with 4bit feature fields and a default safe value of
594  * 0. Covers the following 32bit registers:
595  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
596  */
597 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
598 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
599 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
600 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
601 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
602 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
603 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
604 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
605 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
606 	ARM64_FTR_END,
607 };
608 
609 /* Table for a single 32bit feature value */
610 static const struct arm64_ftr_bits ftr_single32[] = {
611 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
612 	ARM64_FTR_END,
613 };
614 
615 static const struct arm64_ftr_bits ftr_raz[] = {
616 	ARM64_FTR_END,
617 };
618 
619 #define __ARM64_FTR_REG_OVERRIDE(id_str, id, table, ovr) {	\
620 		.sys_id = id,					\
621 		.reg = 	&(struct arm64_ftr_reg){		\
622 			.name = id_str,				\
623 			.override = (ovr),			\
624 			.ftr_bits = &((table)[0]),		\
625 	}}
626 
627 #define ARM64_FTR_REG_OVERRIDE(id, table, ovr)	\
628 	__ARM64_FTR_REG_OVERRIDE(#id, id, table, ovr)
629 
630 #define ARM64_FTR_REG(id, table)		\
631 	__ARM64_FTR_REG_OVERRIDE(#id, id, table, &no_override)
632 
633 struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override;
634 struct arm64_ftr_override __ro_after_init id_aa64pfr1_override;
635 struct arm64_ftr_override __ro_after_init id_aa64isar1_override;
636 struct arm64_ftr_override __ro_after_init id_aa64isar2_override;
637 
638 static const struct __ftr_reg_entry {
639 	u32			sys_id;
640 	struct arm64_ftr_reg 	*reg;
641 } arm64_ftr_regs[] = {
642 
643 	/* Op1 = 0, CRn = 0, CRm = 1 */
644 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
645 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
646 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
647 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
648 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
649 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
650 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
651 
652 	/* Op1 = 0, CRn = 0, CRm = 2 */
653 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
654 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
655 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
656 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
657 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
658 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
659 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
660 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
661 
662 	/* Op1 = 0, CRn = 0, CRm = 3 */
663 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
664 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
665 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
666 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
667 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
668 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
669 
670 	/* Op1 = 0, CRn = 0, CRm = 4 */
671 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
672 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1,
673 			       &id_aa64pfr1_override),
674 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
675 	ARM64_FTR_REG(SYS_ID_AA64SMFR0_EL1, ftr_id_aa64smfr0),
676 
677 	/* Op1 = 0, CRn = 0, CRm = 5 */
678 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
679 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
680 
681 	/* Op1 = 0, CRn = 0, CRm = 6 */
682 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
683 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1,
684 			       &id_aa64isar1_override),
685 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2,
686 			       &id_aa64isar2_override),
687 
688 	/* Op1 = 0, CRn = 0, CRm = 7 */
689 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
690 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1,
691 			       &id_aa64mmfr1_override),
692 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
693 
694 	/* Op1 = 0, CRn = 1, CRm = 2 */
695 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
696 	ARM64_FTR_REG(SYS_SMCR_EL1, ftr_smcr),
697 
698 	/* Op1 = 1, CRn = 0, CRm = 0 */
699 	ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
700 
701 	/* Op1 = 3, CRn = 0, CRm = 0 */
702 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
703 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
704 
705 	/* Op1 = 3, CRn = 14, CRm = 0 */
706 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
707 };
708 
709 static int search_cmp_ftr_reg(const void *id, const void *regp)
710 {
711 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
712 }
713 
714 /*
715  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
716  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
717  * ascending order of sys_id, we use binary search to find a matching
718  * entry.
719  *
720  * returns - Upon success,  matching ftr_reg entry for id.
721  *         - NULL on failure. It is upto the caller to decide
722  *	     the impact of a failure.
723  */
724 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
725 {
726 	const struct __ftr_reg_entry *ret;
727 
728 	ret = bsearch((const void *)(unsigned long)sys_id,
729 			arm64_ftr_regs,
730 			ARRAY_SIZE(arm64_ftr_regs),
731 			sizeof(arm64_ftr_regs[0]),
732 			search_cmp_ftr_reg);
733 	if (ret)
734 		return ret->reg;
735 	return NULL;
736 }
737 
738 /*
739  * get_arm64_ftr_reg - Looks up a feature register entry using
740  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
741  *
742  * returns - Upon success,  matching ftr_reg entry for id.
743  *         - NULL on failure but with an WARN_ON().
744  */
745 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
746 {
747 	struct arm64_ftr_reg *reg;
748 
749 	reg = get_arm64_ftr_reg_nowarn(sys_id);
750 
751 	/*
752 	 * Requesting a non-existent register search is an error. Warn
753 	 * and let the caller handle it.
754 	 */
755 	WARN_ON(!reg);
756 	return reg;
757 }
758 
759 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
760 			       s64 ftr_val)
761 {
762 	u64 mask = arm64_ftr_mask(ftrp);
763 
764 	reg &= ~mask;
765 	reg |= (ftr_val << ftrp->shift) & mask;
766 	return reg;
767 }
768 
769 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
770 				s64 cur)
771 {
772 	s64 ret = 0;
773 
774 	switch (ftrp->type) {
775 	case FTR_EXACT:
776 		ret = ftrp->safe_val;
777 		break;
778 	case FTR_LOWER_SAFE:
779 		ret = min(new, cur);
780 		break;
781 	case FTR_HIGHER_OR_ZERO_SAFE:
782 		if (!cur || !new)
783 			break;
784 		fallthrough;
785 	case FTR_HIGHER_SAFE:
786 		ret = max(new, cur);
787 		break;
788 	default:
789 		BUG();
790 	}
791 
792 	return ret;
793 }
794 
795 static void __init sort_ftr_regs(void)
796 {
797 	unsigned int i;
798 
799 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
800 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
801 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
802 		unsigned int j = 0;
803 
804 		/*
805 		 * Features here must be sorted in descending order with respect
806 		 * to their shift values and should not overlap with each other.
807 		 */
808 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
809 			unsigned int width = ftr_reg->ftr_bits[j].width;
810 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
811 			unsigned int prev_shift;
812 
813 			WARN((shift  + width) > 64,
814 				"%s has invalid feature at shift %d\n",
815 				ftr_reg->name, shift);
816 
817 			/*
818 			 * Skip the first feature. There is nothing to
819 			 * compare against for now.
820 			 */
821 			if (j == 0)
822 				continue;
823 
824 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
825 			WARN((shift + width) > prev_shift,
826 				"%s has feature overlap at shift %d\n",
827 				ftr_reg->name, shift);
828 		}
829 
830 		/*
831 		 * Skip the first register. There is nothing to
832 		 * compare against for now.
833 		 */
834 		if (i == 0)
835 			continue;
836 		/*
837 		 * Registers here must be sorted in ascending order with respect
838 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
839 		 * to work correctly.
840 		 */
841 		BUG_ON(arm64_ftr_regs[i].sys_id <= arm64_ftr_regs[i - 1].sys_id);
842 	}
843 }
844 
845 /*
846  * Initialise the CPU feature register from Boot CPU values.
847  * Also initiliases the strict_mask for the register.
848  * Any bits that are not covered by an arm64_ftr_bits entry are considered
849  * RES0 for the system-wide value, and must strictly match.
850  */
851 static void init_cpu_ftr_reg(u32 sys_reg, u64 new)
852 {
853 	u64 val = 0;
854 	u64 strict_mask = ~0x0ULL;
855 	u64 user_mask = 0;
856 	u64 valid_mask = 0;
857 
858 	const struct arm64_ftr_bits *ftrp;
859 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
860 
861 	if (!reg)
862 		return;
863 
864 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
865 		u64 ftr_mask = arm64_ftr_mask(ftrp);
866 		s64 ftr_new = arm64_ftr_value(ftrp, new);
867 		s64 ftr_ovr = arm64_ftr_value(ftrp, reg->override->val);
868 
869 		if ((ftr_mask & reg->override->mask) == ftr_mask) {
870 			s64 tmp = arm64_ftr_safe_value(ftrp, ftr_ovr, ftr_new);
871 			char *str = NULL;
872 
873 			if (ftr_ovr != tmp) {
874 				/* Unsafe, remove the override */
875 				reg->override->mask &= ~ftr_mask;
876 				reg->override->val &= ~ftr_mask;
877 				tmp = ftr_ovr;
878 				str = "ignoring override";
879 			} else if (ftr_new != tmp) {
880 				/* Override was valid */
881 				ftr_new = tmp;
882 				str = "forced";
883 			} else if (ftr_ovr == tmp) {
884 				/* Override was the safe value */
885 				str = "already set";
886 			}
887 
888 			if (str)
889 				pr_warn("%s[%d:%d]: %s to %llx\n",
890 					reg->name,
891 					ftrp->shift + ftrp->width - 1,
892 					ftrp->shift, str, tmp);
893 		} else if ((ftr_mask & reg->override->val) == ftr_mask) {
894 			reg->override->val &= ~ftr_mask;
895 			pr_warn("%s[%d:%d]: impossible override, ignored\n",
896 				reg->name,
897 				ftrp->shift + ftrp->width - 1,
898 				ftrp->shift);
899 		}
900 
901 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
902 
903 		valid_mask |= ftr_mask;
904 		if (!ftrp->strict)
905 			strict_mask &= ~ftr_mask;
906 		if (ftrp->visible)
907 			user_mask |= ftr_mask;
908 		else
909 			reg->user_val = arm64_ftr_set_value(ftrp,
910 							    reg->user_val,
911 							    ftrp->safe_val);
912 	}
913 
914 	val &= valid_mask;
915 
916 	reg->sys_val = val;
917 	reg->strict_mask = strict_mask;
918 	reg->user_mask = user_mask;
919 }
920 
921 extern const struct arm64_cpu_capabilities arm64_errata[];
922 static const struct arm64_cpu_capabilities arm64_features[];
923 
924 static void __init
925 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
926 {
927 	for (; caps->matches; caps++) {
928 		if (WARN(caps->capability >= ARM64_NCAPS,
929 			"Invalid capability %d\n", caps->capability))
930 			continue;
931 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
932 			"Duplicate entry for capability %d\n",
933 			caps->capability))
934 			continue;
935 		cpu_hwcaps_ptrs[caps->capability] = caps;
936 	}
937 }
938 
939 static void __init init_cpu_hwcaps_indirect_list(void)
940 {
941 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
942 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
943 }
944 
945 static void __init setup_boot_cpu_capabilities(void);
946 
947 static void init_32bit_cpu_features(struct cpuinfo_32bit *info)
948 {
949 	init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
950 	init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
951 	init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
952 	init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
953 	init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
954 	init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
955 	init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
956 	init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
957 	init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
958 	init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
959 	init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
960 	init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
961 	init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
962 	init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
963 	init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
964 	init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
965 	init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
966 	init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
967 	init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
968 	init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
969 	init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
970 }
971 
972 void __init init_cpu_features(struct cpuinfo_arm64 *info)
973 {
974 	/* Before we start using the tables, make sure it is sorted */
975 	sort_ftr_regs();
976 
977 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
978 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
979 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
980 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
981 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
982 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
983 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
984 	init_cpu_ftr_reg(SYS_ID_AA64ISAR2_EL1, info->reg_id_aa64isar2);
985 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
986 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
987 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
988 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
989 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
990 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
991 	init_cpu_ftr_reg(SYS_ID_AA64SMFR0_EL1, info->reg_id_aa64smfr0);
992 
993 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
994 		init_32bit_cpu_features(&info->aarch32);
995 
996 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
997 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
998 		vec_init_vq_map(ARM64_VEC_SVE);
999 	}
1000 
1001 	if (id_aa64pfr1_sme(info->reg_id_aa64pfr1)) {
1002 		init_cpu_ftr_reg(SYS_SMCR_EL1, info->reg_smcr);
1003 		if (IS_ENABLED(CONFIG_ARM64_SME))
1004 			vec_init_vq_map(ARM64_VEC_SME);
1005 	}
1006 
1007 	if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
1008 		init_cpu_ftr_reg(SYS_GMID_EL1, info->reg_gmid);
1009 
1010 	/*
1011 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
1012 	 * before we handle the boot CPU below.
1013 	 */
1014 	init_cpu_hwcaps_indirect_list();
1015 
1016 	/*
1017 	 * Detect and enable early CPU capabilities based on the boot CPU,
1018 	 * after we have initialised the CPU feature infrastructure.
1019 	 */
1020 	setup_boot_cpu_capabilities();
1021 }
1022 
1023 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
1024 {
1025 	const struct arm64_ftr_bits *ftrp;
1026 
1027 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
1028 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
1029 		s64 ftr_new = arm64_ftr_value(ftrp, new);
1030 
1031 		if (ftr_cur == ftr_new)
1032 			continue;
1033 		/* Find a safe value */
1034 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
1035 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
1036 	}
1037 
1038 }
1039 
1040 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
1041 {
1042 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
1043 
1044 	if (!regp)
1045 		return 0;
1046 
1047 	update_cpu_ftr_reg(regp, val);
1048 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
1049 		return 0;
1050 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
1051 			regp->name, boot, cpu, val);
1052 	return 1;
1053 }
1054 
1055 static void relax_cpu_ftr_reg(u32 sys_id, int field)
1056 {
1057 	const struct arm64_ftr_bits *ftrp;
1058 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
1059 
1060 	if (!regp)
1061 		return;
1062 
1063 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
1064 		if (ftrp->shift == field) {
1065 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
1066 			break;
1067 		}
1068 	}
1069 
1070 	/* Bogus field? */
1071 	WARN_ON(!ftrp->width);
1072 }
1073 
1074 static void lazy_init_32bit_cpu_features(struct cpuinfo_arm64 *info,
1075 					 struct cpuinfo_arm64 *boot)
1076 {
1077 	static bool boot_cpu_32bit_regs_overridden = false;
1078 
1079 	if (!allow_mismatched_32bit_el0 || boot_cpu_32bit_regs_overridden)
1080 		return;
1081 
1082 	if (id_aa64pfr0_32bit_el0(boot->reg_id_aa64pfr0))
1083 		return;
1084 
1085 	boot->aarch32 = info->aarch32;
1086 	init_32bit_cpu_features(&boot->aarch32);
1087 	boot_cpu_32bit_regs_overridden = true;
1088 }
1089 
1090 static int update_32bit_cpu_features(int cpu, struct cpuinfo_32bit *info,
1091 				     struct cpuinfo_32bit *boot)
1092 {
1093 	int taint = 0;
1094 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1095 
1096 	/*
1097 	 * If we don't have AArch32 at EL1, then relax the strictness of
1098 	 * EL1-dependent register fields to avoid spurious sanity check fails.
1099 	 */
1100 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
1101 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
1102 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
1103 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
1104 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
1105 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
1106 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
1107 	}
1108 
1109 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
1110 				      info->reg_id_dfr0, boot->reg_id_dfr0);
1111 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
1112 				      info->reg_id_dfr1, boot->reg_id_dfr1);
1113 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
1114 				      info->reg_id_isar0, boot->reg_id_isar0);
1115 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
1116 				      info->reg_id_isar1, boot->reg_id_isar1);
1117 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
1118 				      info->reg_id_isar2, boot->reg_id_isar2);
1119 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
1120 				      info->reg_id_isar3, boot->reg_id_isar3);
1121 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
1122 				      info->reg_id_isar4, boot->reg_id_isar4);
1123 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
1124 				      info->reg_id_isar5, boot->reg_id_isar5);
1125 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
1126 				      info->reg_id_isar6, boot->reg_id_isar6);
1127 
1128 	/*
1129 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
1130 	 * ACTLR formats could differ across CPUs and therefore would have to
1131 	 * be trapped for virtualization anyway.
1132 	 */
1133 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
1134 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
1135 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
1136 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
1137 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
1138 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
1139 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
1140 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
1141 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
1142 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
1143 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
1144 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
1145 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
1146 				      info->reg_id_pfr0, boot->reg_id_pfr0);
1147 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
1148 				      info->reg_id_pfr1, boot->reg_id_pfr1);
1149 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
1150 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1151 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1152 				      info->reg_mvfr0, boot->reg_mvfr0);
1153 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1154 				      info->reg_mvfr1, boot->reg_mvfr1);
1155 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1156 				      info->reg_mvfr2, boot->reg_mvfr2);
1157 
1158 	return taint;
1159 }
1160 
1161 /*
1162  * Update system wide CPU feature registers with the values from a
1163  * non-boot CPU. Also performs SANITY checks to make sure that there
1164  * aren't any insane variations from that of the boot CPU.
1165  */
1166 void update_cpu_features(int cpu,
1167 			 struct cpuinfo_arm64 *info,
1168 			 struct cpuinfo_arm64 *boot)
1169 {
1170 	int taint = 0;
1171 
1172 	/*
1173 	 * The kernel can handle differing I-cache policies, but otherwise
1174 	 * caches should look identical. Userspace JITs will make use of
1175 	 * *minLine.
1176 	 */
1177 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1178 				      info->reg_ctr, boot->reg_ctr);
1179 
1180 	/*
1181 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1182 	 * could result in too much or too little memory being zeroed if a
1183 	 * process is preempted and migrated between CPUs.
1184 	 */
1185 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1186 				      info->reg_dczid, boot->reg_dczid);
1187 
1188 	/* If different, timekeeping will be broken (especially with KVM) */
1189 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1190 				      info->reg_cntfrq, boot->reg_cntfrq);
1191 
1192 	/*
1193 	 * The kernel uses self-hosted debug features and expects CPUs to
1194 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1195 	 * and BRPs to be identical.
1196 	 * ID_AA64DFR1 is currently RES0.
1197 	 */
1198 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1199 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1200 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1201 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1202 	/*
1203 	 * Even in big.LITTLE, processors should be identical instruction-set
1204 	 * wise.
1205 	 */
1206 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1207 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1208 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1209 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1210 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR2_EL1, cpu,
1211 				      info->reg_id_aa64isar2, boot->reg_id_aa64isar2);
1212 
1213 	/*
1214 	 * Differing PARange support is fine as long as all peripherals and
1215 	 * memory are mapped within the minimum PARange of all CPUs.
1216 	 * Linux should not care about secure memory.
1217 	 */
1218 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1219 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1220 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1221 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1222 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1223 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1224 
1225 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1226 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1227 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1228 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1229 
1230 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1231 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1232 
1233 	taint |= check_update_ftr_reg(SYS_ID_AA64SMFR0_EL1, cpu,
1234 				      info->reg_id_aa64smfr0, boot->reg_id_aa64smfr0);
1235 
1236 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1237 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1238 					info->reg_zcr, boot->reg_zcr);
1239 
1240 		/* Probe vector lengths, unless we already gave up on SVE */
1241 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1242 		    !system_capabilities_finalized())
1243 			vec_update_vq_map(ARM64_VEC_SVE);
1244 	}
1245 
1246 	if (id_aa64pfr1_sme(info->reg_id_aa64pfr1)) {
1247 		taint |= check_update_ftr_reg(SYS_SMCR_EL1, cpu,
1248 					info->reg_smcr, boot->reg_smcr);
1249 
1250 		/* Probe vector lengths, unless we already gave up on SME */
1251 		if (id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1)) &&
1252 		    !system_capabilities_finalized())
1253 			vec_update_vq_map(ARM64_VEC_SME);
1254 	}
1255 
1256 	/*
1257 	 * The kernel uses the LDGM/STGM instructions and the number of tags
1258 	 * they read/write depends on the GMID_EL1.BS field. Check that the
1259 	 * value is the same on all CPUs.
1260 	 */
1261 	if (IS_ENABLED(CONFIG_ARM64_MTE) &&
1262 	    id_aa64pfr1_mte(info->reg_id_aa64pfr1)) {
1263 		taint |= check_update_ftr_reg(SYS_GMID_EL1, cpu,
1264 					      info->reg_gmid, boot->reg_gmid);
1265 	}
1266 
1267 	/*
1268 	 * If we don't have AArch32 at all then skip the checks entirely
1269 	 * as the register values may be UNKNOWN and we're not going to be
1270 	 * using them for anything.
1271 	 *
1272 	 * This relies on a sanitised view of the AArch64 ID registers
1273 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1274 	 */
1275 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
1276 		lazy_init_32bit_cpu_features(info, boot);
1277 		taint |= update_32bit_cpu_features(cpu, &info->aarch32,
1278 						   &boot->aarch32);
1279 	}
1280 
1281 	/*
1282 	 * Mismatched CPU features are a recipe for disaster. Don't even
1283 	 * pretend to support them.
1284 	 */
1285 	if (taint) {
1286 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1287 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1288 	}
1289 }
1290 
1291 u64 read_sanitised_ftr_reg(u32 id)
1292 {
1293 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1294 
1295 	if (!regp)
1296 		return 0;
1297 	return regp->sys_val;
1298 }
1299 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
1300 
1301 #define read_sysreg_case(r)	\
1302 	case r:		val = read_sysreg_s(r); break;
1303 
1304 /*
1305  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1306  * Read the system register on the current CPU
1307  */
1308 u64 __read_sysreg_by_encoding(u32 sys_id)
1309 {
1310 	struct arm64_ftr_reg *regp;
1311 	u64 val;
1312 
1313 	switch (sys_id) {
1314 	read_sysreg_case(SYS_ID_PFR0_EL1);
1315 	read_sysreg_case(SYS_ID_PFR1_EL1);
1316 	read_sysreg_case(SYS_ID_PFR2_EL1);
1317 	read_sysreg_case(SYS_ID_DFR0_EL1);
1318 	read_sysreg_case(SYS_ID_DFR1_EL1);
1319 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1320 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1321 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1322 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1323 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1324 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1325 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1326 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1327 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1328 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1329 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1330 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1331 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1332 	read_sysreg_case(SYS_MVFR0_EL1);
1333 	read_sysreg_case(SYS_MVFR1_EL1);
1334 	read_sysreg_case(SYS_MVFR2_EL1);
1335 
1336 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1337 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1338 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1339 	read_sysreg_case(SYS_ID_AA64SMFR0_EL1);
1340 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1341 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1342 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1343 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1344 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1345 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1346 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1347 	read_sysreg_case(SYS_ID_AA64ISAR2_EL1);
1348 
1349 	read_sysreg_case(SYS_CNTFRQ_EL0);
1350 	read_sysreg_case(SYS_CTR_EL0);
1351 	read_sysreg_case(SYS_DCZID_EL0);
1352 
1353 	default:
1354 		BUG();
1355 		return 0;
1356 	}
1357 
1358 	regp  = get_arm64_ftr_reg(sys_id);
1359 	if (regp) {
1360 		val &= ~regp->override->mask;
1361 		val |= (regp->override->val & regp->override->mask);
1362 	}
1363 
1364 	return val;
1365 }
1366 
1367 #include <linux/irqchip/arm-gic-v3.h>
1368 
1369 static bool
1370 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1371 {
1372 	int val = cpuid_feature_extract_field_width(reg, entry->field_pos,
1373 						    entry->field_width,
1374 						    entry->sign);
1375 
1376 	return val >= entry->min_field_value;
1377 }
1378 
1379 static bool
1380 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1381 {
1382 	u64 val;
1383 
1384 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1385 	if (scope == SCOPE_SYSTEM)
1386 		val = read_sanitised_ftr_reg(entry->sys_reg);
1387 	else
1388 		val = __read_sysreg_by_encoding(entry->sys_reg);
1389 
1390 	return feature_matches(val, entry);
1391 }
1392 
1393 const struct cpumask *system_32bit_el0_cpumask(void)
1394 {
1395 	if (!system_supports_32bit_el0())
1396 		return cpu_none_mask;
1397 
1398 	if (static_branch_unlikely(&arm64_mismatched_32bit_el0))
1399 		return cpu_32bit_el0_mask;
1400 
1401 	return cpu_possible_mask;
1402 }
1403 
1404 static int __init parse_32bit_el0_param(char *str)
1405 {
1406 	allow_mismatched_32bit_el0 = true;
1407 	return 0;
1408 }
1409 early_param("allow_mismatched_32bit_el0", parse_32bit_el0_param);
1410 
1411 static ssize_t aarch32_el0_show(struct device *dev,
1412 				struct device_attribute *attr, char *buf)
1413 {
1414 	const struct cpumask *mask = system_32bit_el0_cpumask();
1415 
1416 	return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(mask));
1417 }
1418 static const DEVICE_ATTR_RO(aarch32_el0);
1419 
1420 static int __init aarch32_el0_sysfs_init(void)
1421 {
1422 	if (!allow_mismatched_32bit_el0)
1423 		return 0;
1424 
1425 	return device_create_file(cpu_subsys.dev_root, &dev_attr_aarch32_el0);
1426 }
1427 device_initcall(aarch32_el0_sysfs_init);
1428 
1429 static bool has_32bit_el0(const struct arm64_cpu_capabilities *entry, int scope)
1430 {
1431 	if (!has_cpuid_feature(entry, scope))
1432 		return allow_mismatched_32bit_el0;
1433 
1434 	if (scope == SCOPE_SYSTEM)
1435 		pr_info("detected: 32-bit EL0 Support\n");
1436 
1437 	return true;
1438 }
1439 
1440 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1441 {
1442 	bool has_sre;
1443 
1444 	if (!has_cpuid_feature(entry, scope))
1445 		return false;
1446 
1447 	has_sre = gic_enable_sre();
1448 	if (!has_sre)
1449 		pr_warn_once("%s present but disabled by higher exception level\n",
1450 			     entry->desc);
1451 
1452 	return has_sre;
1453 }
1454 
1455 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1456 {
1457 	u32 midr = read_cpuid_id();
1458 
1459 	/* Cavium ThunderX pass 1.x and 2.x */
1460 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1461 		MIDR_CPU_VAR_REV(0, 0),
1462 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1463 }
1464 
1465 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1466 {
1467 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1468 
1469 	return cpuid_feature_extract_signed_field(pfr0,
1470 					ID_AA64PFR0_FP_SHIFT) < 0;
1471 }
1472 
1473 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1474 			  int scope)
1475 {
1476 	u64 ctr;
1477 
1478 	if (scope == SCOPE_SYSTEM)
1479 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1480 	else
1481 		ctr = read_cpuid_effective_cachetype();
1482 
1483 	return ctr & BIT(CTR_IDC_SHIFT);
1484 }
1485 
1486 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1487 {
1488 	/*
1489 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1490 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1491 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1492 	 * value.
1493 	 */
1494 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1495 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1496 }
1497 
1498 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1499 			  int scope)
1500 {
1501 	u64 ctr;
1502 
1503 	if (scope == SCOPE_SYSTEM)
1504 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1505 	else
1506 		ctr = read_cpuid_cachetype();
1507 
1508 	return ctr & BIT(CTR_DIC_SHIFT);
1509 }
1510 
1511 static bool __maybe_unused
1512 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1513 {
1514 	/*
1515 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1516 	 * may share TLB entries with a CPU stuck in the crashed
1517 	 * kernel.
1518 	 */
1519 	if (is_kdump_kernel())
1520 		return false;
1521 
1522 	if (cpus_have_const_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
1523 		return false;
1524 
1525 	return has_cpuid_feature(entry, scope);
1526 }
1527 
1528 /*
1529  * This check is triggered during the early boot before the cpufeature
1530  * is initialised. Checking the status on the local CPU allows the boot
1531  * CPU to detect the need for non-global mappings and thus avoiding a
1532  * pagetable re-write after all the CPUs are booted. This check will be
1533  * anyway run on individual CPUs, allowing us to get the consistent
1534  * state once the SMP CPUs are up and thus make the switch to non-global
1535  * mappings if required.
1536  */
1537 bool kaslr_requires_kpti(void)
1538 {
1539 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1540 		return false;
1541 
1542 	/*
1543 	 * E0PD does a similar job to KPTI so can be used instead
1544 	 * where available.
1545 	 */
1546 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1547 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1548 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1549 						ID_AA64MMFR2_E0PD_SHIFT))
1550 			return false;
1551 	}
1552 
1553 	/*
1554 	 * Systems affected by Cavium erratum 24756 are incompatible
1555 	 * with KPTI.
1556 	 */
1557 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1558 		extern const struct midr_range cavium_erratum_27456_cpus[];
1559 
1560 		if (is_midr_in_range_list(read_cpuid_id(),
1561 					  cavium_erratum_27456_cpus))
1562 			return false;
1563 	}
1564 
1565 	return kaslr_offset() > 0;
1566 }
1567 
1568 static bool __meltdown_safe = true;
1569 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1570 
1571 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1572 				int scope)
1573 {
1574 	/* List of CPUs that are not vulnerable and don't need KPTI */
1575 	static const struct midr_range kpti_safe_list[] = {
1576 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1577 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1578 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1579 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1580 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1581 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1582 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1583 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1584 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1585 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1586 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1587 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_GOLD),
1588 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
1589 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1590 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1591 		{ /* sentinel */ }
1592 	};
1593 	char const *str = "kpti command line option";
1594 	bool meltdown_safe;
1595 
1596 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1597 
1598 	/* Defer to CPU feature registers */
1599 	if (has_cpuid_feature(entry, scope))
1600 		meltdown_safe = true;
1601 
1602 	if (!meltdown_safe)
1603 		__meltdown_safe = false;
1604 
1605 	/*
1606 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1607 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1608 	 * ends as well as you might imagine. Don't even try. We cannot rely
1609 	 * on the cpus_have_*cap() helpers here to detect the CPU erratum
1610 	 * because cpucap detection order may change. However, since we know
1611 	 * affected CPUs are always in a homogeneous configuration, it is
1612 	 * safe to rely on this_cpu_has_cap() here.
1613 	 */
1614 	if (this_cpu_has_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1615 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1616 		__kpti_forced = -1;
1617 	}
1618 
1619 	/* Useful for KASLR robustness */
1620 	if (kaslr_requires_kpti()) {
1621 		if (!__kpti_forced) {
1622 			str = "KASLR";
1623 			__kpti_forced = 1;
1624 		}
1625 	}
1626 
1627 	if (cpu_mitigations_off() && !__kpti_forced) {
1628 		str = "mitigations=off";
1629 		__kpti_forced = -1;
1630 	}
1631 
1632 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1633 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1634 		return false;
1635 	}
1636 
1637 	/* Forced? */
1638 	if (__kpti_forced) {
1639 		pr_info_once("kernel page table isolation forced %s by %s\n",
1640 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1641 		return __kpti_forced > 0;
1642 	}
1643 
1644 	return !meltdown_safe;
1645 }
1646 
1647 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1648 static void __nocfi
1649 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1650 {
1651 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1652 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1653 	kpti_remap_fn *remap_fn;
1654 
1655 	int cpu = smp_processor_id();
1656 
1657 	if (__this_cpu_read(this_cpu_vector) == vectors) {
1658 		const char *v = arm64_get_bp_hardening_vector(EL1_VECTOR_KPTI);
1659 
1660 		__this_cpu_write(this_cpu_vector, v);
1661 	}
1662 
1663 	/*
1664 	 * We don't need to rewrite the page-tables if either we've done
1665 	 * it already or we have KASLR enabled and therefore have not
1666 	 * created any global mappings at all.
1667 	 */
1668 	if (arm64_use_ng_mappings)
1669 		return;
1670 
1671 	remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));
1672 
1673 	cpu_install_idmap();
1674 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1675 	cpu_uninstall_idmap();
1676 
1677 	if (!cpu)
1678 		arm64_use_ng_mappings = true;
1679 }
1680 #else
1681 static void
1682 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1683 {
1684 }
1685 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1686 
1687 static int __init parse_kpti(char *str)
1688 {
1689 	bool enabled;
1690 	int ret = strtobool(str, &enabled);
1691 
1692 	if (ret)
1693 		return ret;
1694 
1695 	__kpti_forced = enabled ? 1 : -1;
1696 	return 0;
1697 }
1698 early_param("kpti", parse_kpti);
1699 
1700 #ifdef CONFIG_ARM64_HW_AFDBM
1701 static inline void __cpu_enable_hw_dbm(void)
1702 {
1703 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1704 
1705 	write_sysreg(tcr, tcr_el1);
1706 	isb();
1707 	local_flush_tlb_all();
1708 }
1709 
1710 static bool cpu_has_broken_dbm(void)
1711 {
1712 	/* List of CPUs which have broken DBM support. */
1713 	static const struct midr_range cpus[] = {
1714 #ifdef CONFIG_ARM64_ERRATUM_1024718
1715 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1716 		/* Kryo4xx Silver (rdpe => r1p0) */
1717 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1718 #endif
1719 #ifdef CONFIG_ARM64_ERRATUM_2051678
1720 		MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 2),
1721 #endif
1722 		{},
1723 	};
1724 
1725 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1726 }
1727 
1728 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1729 {
1730 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1731 	       !cpu_has_broken_dbm();
1732 }
1733 
1734 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1735 {
1736 	if (cpu_can_use_dbm(cap))
1737 		__cpu_enable_hw_dbm();
1738 }
1739 
1740 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1741 		       int __unused)
1742 {
1743 	static bool detected = false;
1744 	/*
1745 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1746 	 * run a mix of CPUs with and without the feature. So, we
1747 	 * unconditionally enable the capability to allow any late CPU
1748 	 * to use the feature. We only enable the control bits on the
1749 	 * CPU, if it actually supports.
1750 	 *
1751 	 * We have to make sure we print the "feature" detection only
1752 	 * when at least one CPU actually uses it. So check if this CPU
1753 	 * can actually use it and print the message exactly once.
1754 	 *
1755 	 * This is safe as all CPUs (including secondary CPUs - due to the
1756 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1757 	 * goes through the "matches" check exactly once. Also if a CPU
1758 	 * matches the criteria, it is guaranteed that the CPU will turn
1759 	 * the DBM on, as the capability is unconditionally enabled.
1760 	 */
1761 	if (!detected && cpu_can_use_dbm(cap)) {
1762 		detected = true;
1763 		pr_info("detected: Hardware dirty bit management\n");
1764 	}
1765 
1766 	return true;
1767 }
1768 
1769 #endif
1770 
1771 #ifdef CONFIG_ARM64_AMU_EXTN
1772 
1773 /*
1774  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1775  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1776  * information regarding all the events that it supports. When a CPU bit is
1777  * set in the cpumask, the user of this feature can only rely on the presence
1778  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1779  * counters are enabled or access to these counters is enabled by code
1780  * executed at higher exception levels (firmware).
1781  */
1782 static struct cpumask amu_cpus __read_mostly;
1783 
1784 bool cpu_has_amu_feat(int cpu)
1785 {
1786 	return cpumask_test_cpu(cpu, &amu_cpus);
1787 }
1788 
1789 int get_cpu_with_amu_feat(void)
1790 {
1791 	return cpumask_any(&amu_cpus);
1792 }
1793 
1794 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1795 {
1796 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1797 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1798 			smp_processor_id());
1799 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1800 		update_freq_counters_refs();
1801 	}
1802 }
1803 
1804 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1805 		    int __unused)
1806 {
1807 	/*
1808 	 * The AMU extension is a non-conflicting feature: the kernel can
1809 	 * safely run a mix of CPUs with and without support for the
1810 	 * activity monitors extension. Therefore, unconditionally enable
1811 	 * the capability to allow any late CPU to use the feature.
1812 	 *
1813 	 * With this feature unconditionally enabled, the cpu_enable
1814 	 * function will be called for all CPUs that match the criteria,
1815 	 * including secondary and hotplugged, marking this feature as
1816 	 * present on that respective CPU. The enable function will also
1817 	 * print a detection message.
1818 	 */
1819 
1820 	return true;
1821 }
1822 #else
1823 int get_cpu_with_amu_feat(void)
1824 {
1825 	return nr_cpu_ids;
1826 }
1827 #endif
1828 
1829 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1830 {
1831 	return is_kernel_in_hyp_mode();
1832 }
1833 
1834 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1835 {
1836 	/*
1837 	 * Copy register values that aren't redirected by hardware.
1838 	 *
1839 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1840 	 * this value to tpidr_el2 before we patch the code. Once we've done
1841 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1842 	 * do anything here.
1843 	 */
1844 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1845 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1846 }
1847 
1848 #ifdef CONFIG_ARM64_PAN
1849 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1850 {
1851 	/*
1852 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1853 	 * is discarded once we return from the exception.
1854 	 */
1855 	WARN_ON_ONCE(in_interrupt());
1856 
1857 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1858 	set_pstate_pan(1);
1859 }
1860 #endif /* CONFIG_ARM64_PAN */
1861 
1862 #ifdef CONFIG_ARM64_RAS_EXTN
1863 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1864 {
1865 	/* Firmware may have left a deferred SError in this register. */
1866 	write_sysreg_s(0, SYS_DISR_EL1);
1867 }
1868 #endif /* CONFIG_ARM64_RAS_EXTN */
1869 
1870 #ifdef CONFIG_ARM64_PTR_AUTH
1871 static bool has_address_auth_cpucap(const struct arm64_cpu_capabilities *entry, int scope)
1872 {
1873 	int boot_val, sec_val;
1874 
1875 	/* We don't expect to be called with SCOPE_SYSTEM */
1876 	WARN_ON(scope == SCOPE_SYSTEM);
1877 	/*
1878 	 * The ptr-auth feature levels are not intercompatible with lower
1879 	 * levels. Hence we must match ptr-auth feature level of the secondary
1880 	 * CPUs with that of the boot CPU. The level of boot cpu is fetched
1881 	 * from the sanitised register whereas direct register read is done for
1882 	 * the secondary CPUs.
1883 	 * The sanitised feature state is guaranteed to match that of the
1884 	 * boot CPU as a mismatched secondary CPU is parked before it gets
1885 	 * a chance to update the state, with the capability.
1886 	 */
1887 	boot_val = cpuid_feature_extract_field(read_sanitised_ftr_reg(entry->sys_reg),
1888 					       entry->field_pos, entry->sign);
1889 	if (scope & SCOPE_BOOT_CPU)
1890 		return boot_val >= entry->min_field_value;
1891 	/* Now check for the secondary CPUs with SCOPE_LOCAL_CPU scope */
1892 	sec_val = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg),
1893 					      entry->field_pos, entry->sign);
1894 	return (sec_val >= entry->min_field_value) && (sec_val == boot_val);
1895 }
1896 
1897 static bool has_address_auth_metacap(const struct arm64_cpu_capabilities *entry,
1898 				     int scope)
1899 {
1900 	bool api = has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_IMP_DEF], scope);
1901 	bool apa = has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA5], scope);
1902 	bool apa3 = has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA3], scope);
1903 
1904 	return apa || apa3 || api;
1905 }
1906 
1907 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1908 			     int __unused)
1909 {
1910 	bool gpi = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1911 	bool gpa = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH_QARMA5);
1912 	bool gpa3 = __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH_QARMA3);
1913 
1914 	return gpa || gpa3 || gpi;
1915 }
1916 #endif /* CONFIG_ARM64_PTR_AUTH */
1917 
1918 #ifdef CONFIG_ARM64_E0PD
1919 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1920 {
1921 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1922 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1923 }
1924 #endif /* CONFIG_ARM64_E0PD */
1925 
1926 #ifdef CONFIG_ARM64_PSEUDO_NMI
1927 static bool enable_pseudo_nmi;
1928 
1929 static int __init early_enable_pseudo_nmi(char *p)
1930 {
1931 	return strtobool(p, &enable_pseudo_nmi);
1932 }
1933 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1934 
1935 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1936 				   int scope)
1937 {
1938 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1939 }
1940 #endif
1941 
1942 #ifdef CONFIG_ARM64_BTI
1943 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1944 {
1945 	/*
1946 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1947 	 * function entry points using BR is a requirement for
1948 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1949 	 * So, be strict and forbid other BRs using other registers to
1950 	 * jump onto a PACIxSP instruction:
1951 	 */
1952 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1953 	isb();
1954 }
1955 #endif /* CONFIG_ARM64_BTI */
1956 
1957 #ifdef CONFIG_ARM64_MTE
1958 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
1959 {
1960 	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0);
1961 	isb();
1962 
1963 	/*
1964 	 * Clear the tags in the zero page. This needs to be done via the
1965 	 * linear map which has the Tagged attribute.
1966 	 */
1967 	if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
1968 		mte_clear_page_tags(lm_alias(empty_zero_page));
1969 
1970 	kasan_init_hw_tags_cpu();
1971 }
1972 #endif /* CONFIG_ARM64_MTE */
1973 
1974 #ifdef CONFIG_KVM
1975 static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
1976 {
1977 	return kvm_get_mode() == KVM_MODE_PROTECTED;
1978 }
1979 #endif /* CONFIG_KVM */
1980 
1981 /* Internal helper functions to match cpu capability type */
1982 static bool
1983 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1984 {
1985 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1986 }
1987 
1988 static bool
1989 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1990 {
1991 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1992 }
1993 
1994 static bool
1995 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1996 {
1997 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1998 }
1999 
2000 static const struct arm64_cpu_capabilities arm64_features[] = {
2001 	{
2002 		.desc = "GIC system register CPU interface",
2003 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
2004 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2005 		.matches = has_useable_gicv3_cpuif,
2006 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2007 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2008 		.field_width = 4,
2009 		.sign = FTR_UNSIGNED,
2010 		.min_field_value = 1,
2011 	},
2012 	{
2013 		.desc = "Enhanced Counter Virtualization",
2014 		.capability = ARM64_HAS_ECV,
2015 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2016 		.matches = has_cpuid_feature,
2017 		.sys_reg = SYS_ID_AA64MMFR0_EL1,
2018 		.field_pos = ID_AA64MMFR0_ECV_SHIFT,
2019 		.field_width = 4,
2020 		.sign = FTR_UNSIGNED,
2021 		.min_field_value = 1,
2022 	},
2023 #ifdef CONFIG_ARM64_PAN
2024 	{
2025 		.desc = "Privileged Access Never",
2026 		.capability = ARM64_HAS_PAN,
2027 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2028 		.matches = has_cpuid_feature,
2029 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
2030 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
2031 		.field_width = 4,
2032 		.sign = FTR_UNSIGNED,
2033 		.min_field_value = 1,
2034 		.cpu_enable = cpu_enable_pan,
2035 	},
2036 #endif /* CONFIG_ARM64_PAN */
2037 #ifdef CONFIG_ARM64_EPAN
2038 	{
2039 		.desc = "Enhanced Privileged Access Never",
2040 		.capability = ARM64_HAS_EPAN,
2041 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2042 		.matches = has_cpuid_feature,
2043 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
2044 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
2045 		.field_width = 4,
2046 		.sign = FTR_UNSIGNED,
2047 		.min_field_value = 3,
2048 	},
2049 #endif /* CONFIG_ARM64_EPAN */
2050 #ifdef CONFIG_ARM64_LSE_ATOMICS
2051 	{
2052 		.desc = "LSE atomic instructions",
2053 		.capability = ARM64_HAS_LSE_ATOMICS,
2054 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2055 		.matches = has_cpuid_feature,
2056 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2057 		.field_pos = ID_AA64ISAR0_EL1_ATOMIC_SHIFT,
2058 		.field_width = 4,
2059 		.sign = FTR_UNSIGNED,
2060 		.min_field_value = 2,
2061 	},
2062 #endif /* CONFIG_ARM64_LSE_ATOMICS */
2063 	{
2064 		.desc = "Software prefetching using PRFM",
2065 		.capability = ARM64_HAS_NO_HW_PREFETCH,
2066 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2067 		.matches = has_no_hw_prefetch,
2068 	},
2069 	{
2070 		.desc = "Virtualization Host Extensions",
2071 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
2072 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2073 		.matches = runs_at_el2,
2074 		.cpu_enable = cpu_copy_el2regs,
2075 	},
2076 	{
2077 		.capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE,
2078 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2079 		.matches = has_32bit_el0,
2080 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2081 		.sign = FTR_UNSIGNED,
2082 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
2083 		.field_width = 4,
2084 		.min_field_value = ID_AA64PFR0_ELx_32BIT_64BIT,
2085 	},
2086 #ifdef CONFIG_KVM
2087 	{
2088 		.desc = "32-bit EL1 Support",
2089 		.capability = ARM64_HAS_32BIT_EL1,
2090 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2091 		.matches = has_cpuid_feature,
2092 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2093 		.sign = FTR_UNSIGNED,
2094 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
2095 		.field_width = 4,
2096 		.min_field_value = ID_AA64PFR0_ELx_32BIT_64BIT,
2097 	},
2098 	{
2099 		.desc = "Protected KVM",
2100 		.capability = ARM64_KVM_PROTECTED_MODE,
2101 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2102 		.matches = is_kvm_protected_mode,
2103 	},
2104 #endif
2105 	{
2106 		.desc = "Kernel page table isolation (KPTI)",
2107 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
2108 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
2109 		/*
2110 		 * The ID feature fields below are used to indicate that
2111 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
2112 		 * more details.
2113 		 */
2114 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2115 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
2116 		.field_width = 4,
2117 		.min_field_value = 1,
2118 		.matches = unmap_kernel_at_el0,
2119 		.cpu_enable = kpti_install_ng_mappings,
2120 	},
2121 	{
2122 		/* FP/SIMD is not implemented */
2123 		.capability = ARM64_HAS_NO_FPSIMD,
2124 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
2125 		.min_field_value = 0,
2126 		.matches = has_no_fpsimd,
2127 	},
2128 #ifdef CONFIG_ARM64_PMEM
2129 	{
2130 		.desc = "Data cache clean to Point of Persistence",
2131 		.capability = ARM64_HAS_DCPOP,
2132 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2133 		.matches = has_cpuid_feature,
2134 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2135 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
2136 		.field_width = 4,
2137 		.min_field_value = 1,
2138 	},
2139 	{
2140 		.desc = "Data cache clean to Point of Deep Persistence",
2141 		.capability = ARM64_HAS_DCPODP,
2142 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2143 		.matches = has_cpuid_feature,
2144 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2145 		.sign = FTR_UNSIGNED,
2146 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
2147 		.field_width = 4,
2148 		.min_field_value = 2,
2149 	},
2150 #endif
2151 #ifdef CONFIG_ARM64_SVE
2152 	{
2153 		.desc = "Scalable Vector Extension",
2154 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2155 		.capability = ARM64_SVE,
2156 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2157 		.sign = FTR_UNSIGNED,
2158 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
2159 		.field_width = 4,
2160 		.min_field_value = ID_AA64PFR0_SVE,
2161 		.matches = has_cpuid_feature,
2162 		.cpu_enable = sve_kernel_enable,
2163 	},
2164 #endif /* CONFIG_ARM64_SVE */
2165 #ifdef CONFIG_ARM64_RAS_EXTN
2166 	{
2167 		.desc = "RAS Extension Support",
2168 		.capability = ARM64_HAS_RAS_EXTN,
2169 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2170 		.matches = has_cpuid_feature,
2171 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2172 		.sign = FTR_UNSIGNED,
2173 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
2174 		.field_width = 4,
2175 		.min_field_value = ID_AA64PFR0_RAS_V1,
2176 		.cpu_enable = cpu_clear_disr,
2177 	},
2178 #endif /* CONFIG_ARM64_RAS_EXTN */
2179 #ifdef CONFIG_ARM64_AMU_EXTN
2180 	{
2181 		/*
2182 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
2183 		 * Therefore, don't provide .desc as we don't want the detection
2184 		 * message to be shown until at least one CPU is detected to
2185 		 * support the feature.
2186 		 */
2187 		.capability = ARM64_HAS_AMU_EXTN,
2188 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2189 		.matches = has_amu,
2190 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2191 		.sign = FTR_UNSIGNED,
2192 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
2193 		.field_width = 4,
2194 		.min_field_value = ID_AA64PFR0_AMU,
2195 		.cpu_enable = cpu_amu_enable,
2196 	},
2197 #endif /* CONFIG_ARM64_AMU_EXTN */
2198 	{
2199 		.desc = "Data cache clean to the PoU not required for I/D coherence",
2200 		.capability = ARM64_HAS_CACHE_IDC,
2201 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2202 		.matches = has_cache_idc,
2203 		.cpu_enable = cpu_emulate_effective_ctr,
2204 	},
2205 	{
2206 		.desc = "Instruction cache invalidation not required for I/D coherence",
2207 		.capability = ARM64_HAS_CACHE_DIC,
2208 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2209 		.matches = has_cache_dic,
2210 	},
2211 	{
2212 		.desc = "Stage-2 Force Write-Back",
2213 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2214 		.capability = ARM64_HAS_STAGE2_FWB,
2215 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2216 		.sign = FTR_UNSIGNED,
2217 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
2218 		.field_width = 4,
2219 		.min_field_value = 1,
2220 		.matches = has_cpuid_feature,
2221 	},
2222 	{
2223 		.desc = "ARMv8.4 Translation Table Level",
2224 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2225 		.capability = ARM64_HAS_ARMv8_4_TTL,
2226 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2227 		.sign = FTR_UNSIGNED,
2228 		.field_pos = ID_AA64MMFR2_TTL_SHIFT,
2229 		.field_width = 4,
2230 		.min_field_value = 1,
2231 		.matches = has_cpuid_feature,
2232 	},
2233 	{
2234 		.desc = "TLB range maintenance instructions",
2235 		.capability = ARM64_HAS_TLB_RANGE,
2236 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2237 		.matches = has_cpuid_feature,
2238 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2239 		.field_pos = ID_AA64ISAR0_EL1_TLB_SHIFT,
2240 		.field_width = 4,
2241 		.sign = FTR_UNSIGNED,
2242 		.min_field_value = ID_AA64ISAR0_EL1_TLB_RANGE,
2243 	},
2244 #ifdef CONFIG_ARM64_HW_AFDBM
2245 	{
2246 		/*
2247 		 * Since we turn this on always, we don't want the user to
2248 		 * think that the feature is available when it may not be.
2249 		 * So hide the description.
2250 		 *
2251 		 * .desc = "Hardware pagetable Dirty Bit Management",
2252 		 *
2253 		 */
2254 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2255 		.capability = ARM64_HW_DBM,
2256 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
2257 		.sign = FTR_UNSIGNED,
2258 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
2259 		.field_width = 4,
2260 		.min_field_value = 2,
2261 		.matches = has_hw_dbm,
2262 		.cpu_enable = cpu_enable_hw_dbm,
2263 	},
2264 #endif
2265 	{
2266 		.desc = "CRC32 instructions",
2267 		.capability = ARM64_HAS_CRC32,
2268 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2269 		.matches = has_cpuid_feature,
2270 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2271 		.field_pos = ID_AA64ISAR0_EL1_CRC32_SHIFT,
2272 		.field_width = 4,
2273 		.min_field_value = 1,
2274 	},
2275 	{
2276 		.desc = "Speculative Store Bypassing Safe (SSBS)",
2277 		.capability = ARM64_SSBS,
2278 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2279 		.matches = has_cpuid_feature,
2280 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2281 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
2282 		.field_width = 4,
2283 		.sign = FTR_UNSIGNED,
2284 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
2285 	},
2286 #ifdef CONFIG_ARM64_CNP
2287 	{
2288 		.desc = "Common not Private translations",
2289 		.capability = ARM64_HAS_CNP,
2290 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2291 		.matches = has_useable_cnp,
2292 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2293 		.sign = FTR_UNSIGNED,
2294 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
2295 		.field_width = 4,
2296 		.min_field_value = 1,
2297 		.cpu_enable = cpu_enable_cnp,
2298 	},
2299 #endif
2300 	{
2301 		.desc = "Speculation barrier (SB)",
2302 		.capability = ARM64_HAS_SB,
2303 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2304 		.matches = has_cpuid_feature,
2305 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2306 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
2307 		.field_width = 4,
2308 		.sign = FTR_UNSIGNED,
2309 		.min_field_value = 1,
2310 	},
2311 #ifdef CONFIG_ARM64_PTR_AUTH
2312 	{
2313 		.desc = "Address authentication (architected QARMA5 algorithm)",
2314 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA5,
2315 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2316 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2317 		.sign = FTR_UNSIGNED,
2318 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
2319 		.field_width = 4,
2320 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
2321 		.matches = has_address_auth_cpucap,
2322 	},
2323 	{
2324 		.desc = "Address authentication (architected QARMA3 algorithm)",
2325 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH_QARMA3,
2326 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2327 		.sys_reg = SYS_ID_AA64ISAR2_EL1,
2328 		.sign = FTR_UNSIGNED,
2329 		.field_pos = ID_AA64ISAR2_APA3_SHIFT,
2330 		.field_width = 4,
2331 		.min_field_value = ID_AA64ISAR2_APA3_ARCHITECTED,
2332 		.matches = has_address_auth_cpucap,
2333 	},
2334 	{
2335 		.desc = "Address authentication (IMP DEF algorithm)",
2336 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2337 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2338 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2339 		.sign = FTR_UNSIGNED,
2340 		.field_pos = ID_AA64ISAR1_API_SHIFT,
2341 		.field_width = 4,
2342 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
2343 		.matches = has_address_auth_cpucap,
2344 	},
2345 	{
2346 		.capability = ARM64_HAS_ADDRESS_AUTH,
2347 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2348 		.matches = has_address_auth_metacap,
2349 	},
2350 	{
2351 		.desc = "Generic authentication (architected QARMA5 algorithm)",
2352 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH_QARMA5,
2353 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2354 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2355 		.sign = FTR_UNSIGNED,
2356 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
2357 		.field_width = 4,
2358 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
2359 		.matches = has_cpuid_feature,
2360 	},
2361 	{
2362 		.desc = "Generic authentication (architected QARMA3 algorithm)",
2363 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH_QARMA3,
2364 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2365 		.sys_reg = SYS_ID_AA64ISAR2_EL1,
2366 		.sign = FTR_UNSIGNED,
2367 		.field_pos = ID_AA64ISAR2_GPA3_SHIFT,
2368 		.field_width = 4,
2369 		.min_field_value = ID_AA64ISAR2_GPA3_ARCHITECTED,
2370 		.matches = has_cpuid_feature,
2371 	},
2372 	{
2373 		.desc = "Generic authentication (IMP DEF algorithm)",
2374 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2375 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2376 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2377 		.sign = FTR_UNSIGNED,
2378 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
2379 		.field_width = 4,
2380 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
2381 		.matches = has_cpuid_feature,
2382 	},
2383 	{
2384 		.capability = ARM64_HAS_GENERIC_AUTH,
2385 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2386 		.matches = has_generic_auth,
2387 	},
2388 #endif /* CONFIG_ARM64_PTR_AUTH */
2389 #ifdef CONFIG_ARM64_PSEUDO_NMI
2390 	{
2391 		/*
2392 		 * Depends on having GICv3
2393 		 */
2394 		.desc = "IRQ priority masking",
2395 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2396 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2397 		.matches = can_use_gic_priorities,
2398 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2399 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2400 		.field_width = 4,
2401 		.sign = FTR_UNSIGNED,
2402 		.min_field_value = 1,
2403 	},
2404 #endif
2405 #ifdef CONFIG_ARM64_E0PD
2406 	{
2407 		.desc = "E0PD",
2408 		.capability = ARM64_HAS_E0PD,
2409 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2410 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2411 		.sign = FTR_UNSIGNED,
2412 		.field_width = 4,
2413 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2414 		.matches = has_cpuid_feature,
2415 		.min_field_value = 1,
2416 		.cpu_enable = cpu_enable_e0pd,
2417 	},
2418 #endif
2419 #ifdef CONFIG_ARCH_RANDOM
2420 	{
2421 		.desc = "Random Number Generator",
2422 		.capability = ARM64_HAS_RNG,
2423 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2424 		.matches = has_cpuid_feature,
2425 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2426 		.field_pos = ID_AA64ISAR0_EL1_RNDR_SHIFT,
2427 		.field_width = 4,
2428 		.sign = FTR_UNSIGNED,
2429 		.min_field_value = 1,
2430 	},
2431 #endif
2432 #ifdef CONFIG_ARM64_BTI
2433 	{
2434 		.desc = "Branch Target Identification",
2435 		.capability = ARM64_BTI,
2436 #ifdef CONFIG_ARM64_BTI_KERNEL
2437 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2438 #else
2439 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2440 #endif
2441 		.matches = has_cpuid_feature,
2442 		.cpu_enable = bti_enable,
2443 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2444 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2445 		.field_width = 4,
2446 		.min_field_value = ID_AA64PFR1_BT_BTI,
2447 		.sign = FTR_UNSIGNED,
2448 	},
2449 #endif
2450 #ifdef CONFIG_ARM64_MTE
2451 	{
2452 		.desc = "Memory Tagging Extension",
2453 		.capability = ARM64_MTE,
2454 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2455 		.matches = has_cpuid_feature,
2456 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2457 		.field_pos = ID_AA64PFR1_MTE_SHIFT,
2458 		.field_width = 4,
2459 		.min_field_value = ID_AA64PFR1_MTE,
2460 		.sign = FTR_UNSIGNED,
2461 		.cpu_enable = cpu_enable_mte,
2462 	},
2463 	{
2464 		.desc = "Asymmetric MTE Tag Check Fault",
2465 		.capability = ARM64_MTE_ASYMM,
2466 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2467 		.matches = has_cpuid_feature,
2468 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2469 		.field_pos = ID_AA64PFR1_MTE_SHIFT,
2470 		.field_width = 4,
2471 		.min_field_value = ID_AA64PFR1_MTE_ASYMM,
2472 		.sign = FTR_UNSIGNED,
2473 	},
2474 #endif /* CONFIG_ARM64_MTE */
2475 	{
2476 		.desc = "RCpc load-acquire (LDAPR)",
2477 		.capability = ARM64_HAS_LDAPR,
2478 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2479 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2480 		.sign = FTR_UNSIGNED,
2481 		.field_pos = ID_AA64ISAR1_LRCPC_SHIFT,
2482 		.field_width = 4,
2483 		.matches = has_cpuid_feature,
2484 		.min_field_value = 1,
2485 	},
2486 #ifdef CONFIG_ARM64_SME
2487 	{
2488 		.desc = "Scalable Matrix Extension",
2489 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2490 		.capability = ARM64_SME,
2491 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2492 		.sign = FTR_UNSIGNED,
2493 		.field_pos = ID_AA64PFR1_SME_SHIFT,
2494 		.field_width = 4,
2495 		.min_field_value = ID_AA64PFR1_SME,
2496 		.matches = has_cpuid_feature,
2497 		.cpu_enable = sme_kernel_enable,
2498 	},
2499 	/* FA64 should be sorted after the base SME capability */
2500 	{
2501 		.desc = "FA64",
2502 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2503 		.capability = ARM64_SME_FA64,
2504 		.sys_reg = SYS_ID_AA64SMFR0_EL1,
2505 		.sign = FTR_UNSIGNED,
2506 		.field_pos = ID_AA64SMFR0_FA64_SHIFT,
2507 		.field_width = 1,
2508 		.min_field_value = ID_AA64SMFR0_FA64,
2509 		.matches = has_cpuid_feature,
2510 		.cpu_enable = fa64_kernel_enable,
2511 	},
2512 #endif /* CONFIG_ARM64_SME */
2513 	{
2514 		.desc = "WFx with timeout",
2515 		.capability = ARM64_HAS_WFXT,
2516 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2517 		.sys_reg = SYS_ID_AA64ISAR2_EL1,
2518 		.sign = FTR_UNSIGNED,
2519 		.field_pos = ID_AA64ISAR2_WFXT_SHIFT,
2520 		.field_width = 4,
2521 		.matches = has_cpuid_feature,
2522 		.min_field_value = ID_AA64ISAR2_WFXT_SUPPORTED,
2523 	},
2524 	{},
2525 };
2526 
2527 #define HWCAP_CPUID_MATCH(reg, field, width, s, min_value)			\
2528 		.matches = has_cpuid_feature,					\
2529 		.sys_reg = reg,							\
2530 		.field_pos = field,						\
2531 		.field_width = width,						\
2532 		.sign = s,							\
2533 		.min_field_value = min_value,
2534 
2535 #define __HWCAP_CAP(name, cap_type, cap)					\
2536 		.desc = name,							\
2537 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2538 		.hwcap_type = cap_type,						\
2539 		.hwcap = cap,							\
2540 
2541 #define HWCAP_CAP(reg, field, width, s, min_value, cap_type, cap)		\
2542 	{									\
2543 		__HWCAP_CAP(#cap, cap_type, cap)				\
2544 		HWCAP_CPUID_MATCH(reg, field, width, s, min_value) 		\
2545 	}
2546 
2547 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2548 	{									\
2549 		__HWCAP_CAP(#cap, cap_type, cap)				\
2550 		.matches = cpucap_multi_entry_cap_matches,			\
2551 		.match_list = list,						\
2552 	}
2553 
2554 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2555 	{									\
2556 		__HWCAP_CAP(#cap, cap_type, cap)				\
2557 		.matches = match,						\
2558 	}
2559 
2560 #ifdef CONFIG_ARM64_PTR_AUTH
2561 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2562 	{
2563 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2564 				  4, FTR_UNSIGNED,
2565 				  ID_AA64ISAR1_APA_ARCHITECTED)
2566 	},
2567 	{
2568 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_APA3_SHIFT,
2569 				  4, FTR_UNSIGNED, ID_AA64ISAR2_APA3_ARCHITECTED)
2570 	},
2571 	{
2572 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2573 				  4, FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2574 	},
2575 	{},
2576 };
2577 
2578 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2579 	{
2580 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2581 				  4, FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2582 	},
2583 	{
2584 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_GPA3_SHIFT,
2585 				  4, FTR_UNSIGNED, ID_AA64ISAR2_GPA3_ARCHITECTED)
2586 	},
2587 	{
2588 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2589 				  4, FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2590 	},
2591 	{},
2592 };
2593 #endif
2594 
2595 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2596 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_AES_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2597 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_AES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2598 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SHA1_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2599 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SHA2_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2600 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SHA2_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2601 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_CRC32_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2602 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_ATOMIC_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2603 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_RDM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2604 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SHA3_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2605 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SM3_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2606 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_SM4_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2607 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_DP_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2608 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_FHM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2609 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_TS_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2610 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_TS_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2611 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_EL1_RNDR_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2612 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, 4, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2613 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, 4, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2614 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, 4, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2615 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, 4, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2616 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, 4, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2617 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2618 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2619 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2620 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2621 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2622 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2623 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2624 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2625 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2626 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2627 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2628 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2629 #ifdef CONFIG_ARM64_SVE
2630 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2631 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2632 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2633 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2634 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2635 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2636 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2637 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2638 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2639 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2640 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2641 #endif
2642 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2643 #ifdef CONFIG_ARM64_BTI
2644 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2645 #endif
2646 #ifdef CONFIG_ARM64_PTR_AUTH
2647 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2648 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2649 #endif
2650 #ifdef CONFIG_ARM64_MTE
2651 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE),
2652 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_MTE_ASYMM, CAP_HWCAP, KERNEL_HWCAP_MTE3),
2653 #endif /* CONFIG_ARM64_MTE */
2654 	HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_ECV_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV),
2655 	HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_AFP_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP),
2656 	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_RPRES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RPRES),
2657 	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_WFXT_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_WFXT_SUPPORTED, CAP_HWCAP, KERNEL_HWCAP_WFXT),
2658 #ifdef CONFIG_ARM64_SME
2659 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SME_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_SME, CAP_HWCAP, KERNEL_HWCAP_SME),
2660 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_FA64_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_FA64, CAP_HWCAP, KERNEL_HWCAP_SME_FA64),
2661 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_I16I64_SHIFT, 4, FTR_UNSIGNED, ID_AA64SMFR0_I16I64, CAP_HWCAP, KERNEL_HWCAP_SME_I16I64),
2662 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F64F64_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F64F64, CAP_HWCAP, KERNEL_HWCAP_SME_F64F64),
2663 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_I8I32_SHIFT, 4, FTR_UNSIGNED, ID_AA64SMFR0_I8I32, CAP_HWCAP, KERNEL_HWCAP_SME_I8I32),
2664 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F16F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F16F32, CAP_HWCAP, KERNEL_HWCAP_SME_F16F32),
2665 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_B16F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_B16F32, CAP_HWCAP, KERNEL_HWCAP_SME_B16F32),
2666 	HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F32F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F32F32, CAP_HWCAP, KERNEL_HWCAP_SME_F32F32),
2667 #endif /* CONFIG_ARM64_SME */
2668 	{},
2669 };
2670 
2671 #ifdef CONFIG_COMPAT
2672 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2673 {
2674 	/*
2675 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2676 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2677 	 * check is future proof, by making sure value is non-zero.
2678 	 */
2679 	u32 mvfr1;
2680 
2681 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2682 	if (scope == SCOPE_SYSTEM)
2683 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2684 	else
2685 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2686 
2687 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2688 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2689 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2690 }
2691 #endif
2692 
2693 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2694 #ifdef CONFIG_COMPAT
2695 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2696 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2697 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2698 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, 4, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2699 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, 4, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2700 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 4, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2701 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2702 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2703 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2704 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2705 #endif
2706 	{},
2707 };
2708 
2709 static void cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2710 {
2711 	switch (cap->hwcap_type) {
2712 	case CAP_HWCAP:
2713 		cpu_set_feature(cap->hwcap);
2714 		break;
2715 #ifdef CONFIG_COMPAT
2716 	case CAP_COMPAT_HWCAP:
2717 		compat_elf_hwcap |= (u32)cap->hwcap;
2718 		break;
2719 	case CAP_COMPAT_HWCAP2:
2720 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2721 		break;
2722 #endif
2723 	default:
2724 		WARN_ON(1);
2725 		break;
2726 	}
2727 }
2728 
2729 /* Check if we have a particular HWCAP enabled */
2730 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2731 {
2732 	bool rc;
2733 
2734 	switch (cap->hwcap_type) {
2735 	case CAP_HWCAP:
2736 		rc = cpu_have_feature(cap->hwcap);
2737 		break;
2738 #ifdef CONFIG_COMPAT
2739 	case CAP_COMPAT_HWCAP:
2740 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2741 		break;
2742 	case CAP_COMPAT_HWCAP2:
2743 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2744 		break;
2745 #endif
2746 	default:
2747 		WARN_ON(1);
2748 		rc = false;
2749 	}
2750 
2751 	return rc;
2752 }
2753 
2754 static void setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2755 {
2756 	/* We support emulation of accesses to CPU ID feature registers */
2757 	cpu_set_named_feature(CPUID);
2758 	for (; hwcaps->matches; hwcaps++)
2759 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2760 			cap_set_elf_hwcap(hwcaps);
2761 }
2762 
2763 static void update_cpu_capabilities(u16 scope_mask)
2764 {
2765 	int i;
2766 	const struct arm64_cpu_capabilities *caps;
2767 
2768 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2769 	for (i = 0; i < ARM64_NCAPS; i++) {
2770 		caps = cpu_hwcaps_ptrs[i];
2771 		if (!caps || !(caps->type & scope_mask) ||
2772 		    cpus_have_cap(caps->capability) ||
2773 		    !caps->matches(caps, cpucap_default_scope(caps)))
2774 			continue;
2775 
2776 		if (caps->desc)
2777 			pr_info("detected: %s\n", caps->desc);
2778 		cpus_set_cap(caps->capability);
2779 
2780 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2781 			set_bit(caps->capability, boot_capabilities);
2782 	}
2783 }
2784 
2785 /*
2786  * Enable all the available capabilities on this CPU. The capabilities
2787  * with BOOT_CPU scope are handled separately and hence skipped here.
2788  */
2789 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2790 {
2791 	int i;
2792 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2793 
2794 	for_each_available_cap(i) {
2795 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2796 
2797 		if (WARN_ON(!cap))
2798 			continue;
2799 
2800 		if (!(cap->type & non_boot_scope))
2801 			continue;
2802 
2803 		if (cap->cpu_enable)
2804 			cap->cpu_enable(cap);
2805 	}
2806 	return 0;
2807 }
2808 
2809 /*
2810  * Run through the enabled capabilities and enable() it on all active
2811  * CPUs
2812  */
2813 static void __init enable_cpu_capabilities(u16 scope_mask)
2814 {
2815 	int i;
2816 	const struct arm64_cpu_capabilities *caps;
2817 	bool boot_scope;
2818 
2819 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2820 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2821 
2822 	for (i = 0; i < ARM64_NCAPS; i++) {
2823 		unsigned int num;
2824 
2825 		caps = cpu_hwcaps_ptrs[i];
2826 		if (!caps || !(caps->type & scope_mask))
2827 			continue;
2828 		num = caps->capability;
2829 		if (!cpus_have_cap(num))
2830 			continue;
2831 
2832 		/* Ensure cpus_have_const_cap(num) works */
2833 		static_branch_enable(&cpu_hwcap_keys[num]);
2834 
2835 		if (boot_scope && caps->cpu_enable)
2836 			/*
2837 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2838 			 * before any secondary CPU boots. Thus, each secondary
2839 			 * will enable the capability as appropriate via
2840 			 * check_local_cpu_capabilities(). The only exception is
2841 			 * the boot CPU, for which the capability must be
2842 			 * enabled here. This approach avoids costly
2843 			 * stop_machine() calls for this case.
2844 			 */
2845 			caps->cpu_enable(caps);
2846 	}
2847 
2848 	/*
2849 	 * For all non-boot scope capabilities, use stop_machine()
2850 	 * as it schedules the work allowing us to modify PSTATE,
2851 	 * instead of on_each_cpu() which uses an IPI, giving us a
2852 	 * PSTATE that disappears when we return.
2853 	 */
2854 	if (!boot_scope)
2855 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2856 			     NULL, cpu_online_mask);
2857 }
2858 
2859 /*
2860  * Run through the list of capabilities to check for conflicts.
2861  * If the system has already detected a capability, take necessary
2862  * action on this CPU.
2863  */
2864 static void verify_local_cpu_caps(u16 scope_mask)
2865 {
2866 	int i;
2867 	bool cpu_has_cap, system_has_cap;
2868 	const struct arm64_cpu_capabilities *caps;
2869 
2870 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2871 
2872 	for (i = 0; i < ARM64_NCAPS; i++) {
2873 		caps = cpu_hwcaps_ptrs[i];
2874 		if (!caps || !(caps->type & scope_mask))
2875 			continue;
2876 
2877 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2878 		system_has_cap = cpus_have_cap(caps->capability);
2879 
2880 		if (system_has_cap) {
2881 			/*
2882 			 * Check if the new CPU misses an advertised feature,
2883 			 * which is not safe to miss.
2884 			 */
2885 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2886 				break;
2887 			/*
2888 			 * We have to issue cpu_enable() irrespective of
2889 			 * whether the CPU has it or not, as it is enabeld
2890 			 * system wide. It is upto the call back to take
2891 			 * appropriate action on this CPU.
2892 			 */
2893 			if (caps->cpu_enable)
2894 				caps->cpu_enable(caps);
2895 		} else {
2896 			/*
2897 			 * Check if the CPU has this capability if it isn't
2898 			 * safe to have when the system doesn't.
2899 			 */
2900 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2901 				break;
2902 		}
2903 	}
2904 
2905 	if (i < ARM64_NCAPS) {
2906 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2907 			smp_processor_id(), caps->capability,
2908 			caps->desc, system_has_cap, cpu_has_cap);
2909 
2910 		if (cpucap_panic_on_conflict(caps))
2911 			cpu_panic_kernel();
2912 		else
2913 			cpu_die_early();
2914 	}
2915 }
2916 
2917 /*
2918  * Check for CPU features that are used in early boot
2919  * based on the Boot CPU value.
2920  */
2921 static void check_early_cpu_features(void)
2922 {
2923 	verify_cpu_asid_bits();
2924 
2925 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2926 }
2927 
2928 static void
2929 __verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2930 {
2931 
2932 	for (; caps->matches; caps++)
2933 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2934 			pr_crit("CPU%d: missing HWCAP: %s\n",
2935 					smp_processor_id(), caps->desc);
2936 			cpu_die_early();
2937 		}
2938 }
2939 
2940 static void verify_local_elf_hwcaps(void)
2941 {
2942 	__verify_local_elf_hwcaps(arm64_elf_hwcaps);
2943 
2944 	if (id_aa64pfr0_32bit_el0(read_cpuid(ID_AA64PFR0_EL1)))
2945 		__verify_local_elf_hwcaps(compat_elf_hwcaps);
2946 }
2947 
2948 static void verify_sve_features(void)
2949 {
2950 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2951 	u64 zcr = read_zcr_features();
2952 
2953 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2954 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2955 
2956 	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SVE)) {
2957 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2958 			smp_processor_id());
2959 		cpu_die_early();
2960 	}
2961 
2962 	/* Add checks on other ZCR bits here if necessary */
2963 }
2964 
2965 static void verify_sme_features(void)
2966 {
2967 	u64 safe_smcr = read_sanitised_ftr_reg(SYS_SMCR_EL1);
2968 	u64 smcr = read_smcr_features();
2969 
2970 	unsigned int safe_len = safe_smcr & SMCR_ELx_LEN_MASK;
2971 	unsigned int len = smcr & SMCR_ELx_LEN_MASK;
2972 
2973 	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SME)) {
2974 		pr_crit("CPU%d: SME: vector length support mismatch\n",
2975 			smp_processor_id());
2976 		cpu_die_early();
2977 	}
2978 
2979 	/* Add checks on other SMCR bits here if necessary */
2980 }
2981 
2982 static void verify_hyp_capabilities(void)
2983 {
2984 	u64 safe_mmfr1, mmfr0, mmfr1;
2985 	int parange, ipa_max;
2986 	unsigned int safe_vmid_bits, vmid_bits;
2987 
2988 	if (!IS_ENABLED(CONFIG_KVM))
2989 		return;
2990 
2991 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2992 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2993 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2994 
2995 	/* Verify VMID bits */
2996 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2997 	vmid_bits = get_vmid_bits(mmfr1);
2998 	if (vmid_bits < safe_vmid_bits) {
2999 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
3000 		cpu_die_early();
3001 	}
3002 
3003 	/* Verify IPA range */
3004 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
3005 				ID_AA64MMFR0_PARANGE_SHIFT);
3006 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
3007 	if (ipa_max < get_kvm_ipa_limit()) {
3008 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
3009 		cpu_die_early();
3010 	}
3011 }
3012 
3013 /*
3014  * Run through the enabled system capabilities and enable() it on this CPU.
3015  * The capabilities were decided based on the available CPUs at the boot time.
3016  * Any new CPU should match the system wide status of the capability. If the
3017  * new CPU doesn't have a capability which the system now has enabled, we
3018  * cannot do anything to fix it up and could cause unexpected failures. So
3019  * we park the CPU.
3020  */
3021 static void verify_local_cpu_capabilities(void)
3022 {
3023 	/*
3024 	 * The capabilities with SCOPE_BOOT_CPU are checked from
3025 	 * check_early_cpu_features(), as they need to be verified
3026 	 * on all secondary CPUs.
3027 	 */
3028 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
3029 	verify_local_elf_hwcaps();
3030 
3031 	if (system_supports_sve())
3032 		verify_sve_features();
3033 
3034 	if (system_supports_sme())
3035 		verify_sme_features();
3036 
3037 	if (is_hyp_mode_available())
3038 		verify_hyp_capabilities();
3039 }
3040 
3041 void check_local_cpu_capabilities(void)
3042 {
3043 	/*
3044 	 * All secondary CPUs should conform to the early CPU features
3045 	 * in use by the kernel based on boot CPU.
3046 	 */
3047 	check_early_cpu_features();
3048 
3049 	/*
3050 	 * If we haven't finalised the system capabilities, this CPU gets
3051 	 * a chance to update the errata work arounds and local features.
3052 	 * Otherwise, this CPU should verify that it has all the system
3053 	 * advertised capabilities.
3054 	 */
3055 	if (!system_capabilities_finalized())
3056 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
3057 	else
3058 		verify_local_cpu_capabilities();
3059 }
3060 
3061 static void __init setup_boot_cpu_capabilities(void)
3062 {
3063 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
3064 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
3065 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
3066 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
3067 }
3068 
3069 bool this_cpu_has_cap(unsigned int n)
3070 {
3071 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
3072 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
3073 
3074 		if (cap)
3075 			return cap->matches(cap, SCOPE_LOCAL_CPU);
3076 	}
3077 
3078 	return false;
3079 }
3080 EXPORT_SYMBOL_GPL(this_cpu_has_cap);
3081 
3082 /*
3083  * This helper function is used in a narrow window when,
3084  * - The system wide safe registers are set with all the SMP CPUs and,
3085  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
3086  * In all other cases cpus_have_{const_}cap() should be used.
3087  */
3088 static bool __maybe_unused __system_matches_cap(unsigned int n)
3089 {
3090 	if (n < ARM64_NCAPS) {
3091 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
3092 
3093 		if (cap)
3094 			return cap->matches(cap, SCOPE_SYSTEM);
3095 	}
3096 	return false;
3097 }
3098 
3099 void cpu_set_feature(unsigned int num)
3100 {
3101 	WARN_ON(num >= MAX_CPU_FEATURES);
3102 	elf_hwcap |= BIT(num);
3103 }
3104 
3105 bool cpu_have_feature(unsigned int num)
3106 {
3107 	WARN_ON(num >= MAX_CPU_FEATURES);
3108 	return elf_hwcap & BIT(num);
3109 }
3110 EXPORT_SYMBOL_GPL(cpu_have_feature);
3111 
3112 unsigned long cpu_get_elf_hwcap(void)
3113 {
3114 	/*
3115 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
3116 	 * note that for userspace compatibility we guarantee that bits 62
3117 	 * and 63 will always be returned as 0.
3118 	 */
3119 	return lower_32_bits(elf_hwcap);
3120 }
3121 
3122 unsigned long cpu_get_elf_hwcap2(void)
3123 {
3124 	return upper_32_bits(elf_hwcap);
3125 }
3126 
3127 static void __init setup_system_capabilities(void)
3128 {
3129 	/*
3130 	 * We have finalised the system-wide safe feature
3131 	 * registers, finalise the capabilities that depend
3132 	 * on it. Also enable all the available capabilities,
3133 	 * that are not enabled already.
3134 	 */
3135 	update_cpu_capabilities(SCOPE_SYSTEM);
3136 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
3137 }
3138 
3139 void __init setup_cpu_features(void)
3140 {
3141 	u32 cwg;
3142 
3143 	setup_system_capabilities();
3144 	setup_elf_hwcaps(arm64_elf_hwcaps);
3145 
3146 	if (system_supports_32bit_el0())
3147 		setup_elf_hwcaps(compat_elf_hwcaps);
3148 
3149 	if (system_uses_ttbr0_pan())
3150 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
3151 
3152 	sve_setup();
3153 	sme_setup();
3154 	minsigstksz_setup();
3155 
3156 	/* Advertise that we have computed the system capabilities */
3157 	finalize_system_capabilities();
3158 
3159 	/*
3160 	 * Check for sane CTR_EL0.CWG value.
3161 	 */
3162 	cwg = cache_type_cwg();
3163 	if (!cwg)
3164 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
3165 			ARCH_DMA_MINALIGN);
3166 }
3167 
3168 static int enable_mismatched_32bit_el0(unsigned int cpu)
3169 {
3170 	/*
3171 	 * The first 32-bit-capable CPU we detected and so can no longer
3172 	 * be offlined by userspace. -1 indicates we haven't yet onlined
3173 	 * a 32-bit-capable CPU.
3174 	 */
3175 	static int lucky_winner = -1;
3176 
3177 	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
3178 	bool cpu_32bit = id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0);
3179 
3180 	if (cpu_32bit) {
3181 		cpumask_set_cpu(cpu, cpu_32bit_el0_mask);
3182 		static_branch_enable_cpuslocked(&arm64_mismatched_32bit_el0);
3183 	}
3184 
3185 	if (cpumask_test_cpu(0, cpu_32bit_el0_mask) == cpu_32bit)
3186 		return 0;
3187 
3188 	if (lucky_winner >= 0)
3189 		return 0;
3190 
3191 	/*
3192 	 * We've detected a mismatch. We need to keep one of our CPUs with
3193 	 * 32-bit EL0 online so that is_cpu_allowed() doesn't end up rejecting
3194 	 * every CPU in the system for a 32-bit task.
3195 	 */
3196 	lucky_winner = cpu_32bit ? cpu : cpumask_any_and(cpu_32bit_el0_mask,
3197 							 cpu_active_mask);
3198 	get_cpu_device(lucky_winner)->offline_disabled = true;
3199 	setup_elf_hwcaps(compat_elf_hwcaps);
3200 	pr_info("Asymmetric 32-bit EL0 support detected on CPU %u; CPU hot-unplug disabled on CPU %u\n",
3201 		cpu, lucky_winner);
3202 	return 0;
3203 }
3204 
3205 static int __init init_32bit_el0_mask(void)
3206 {
3207 	if (!allow_mismatched_32bit_el0)
3208 		return 0;
3209 
3210 	if (!zalloc_cpumask_var(&cpu_32bit_el0_mask, GFP_KERNEL))
3211 		return -ENOMEM;
3212 
3213 	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
3214 				 "arm64/mismatched_32bit_el0:online",
3215 				 enable_mismatched_32bit_el0, NULL);
3216 }
3217 subsys_initcall_sync(init_32bit_el0_mask);
3218 
3219 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
3220 {
3221 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
3222 }
3223 
3224 /*
3225  * We emulate only the following system register space.
3226  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
3227  * See Table C5-6 System instruction encodings for System register accesses,
3228  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
3229  */
3230 static inline bool __attribute_const__ is_emulated(u32 id)
3231 {
3232 	return (sys_reg_Op0(id) == 0x3 &&
3233 		sys_reg_CRn(id) == 0x0 &&
3234 		sys_reg_Op1(id) == 0x0 &&
3235 		(sys_reg_CRm(id) == 0 ||
3236 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
3237 }
3238 
3239 /*
3240  * With CRm == 0, reg should be one of :
3241  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
3242  */
3243 static inline int emulate_id_reg(u32 id, u64 *valp)
3244 {
3245 	switch (id) {
3246 	case SYS_MIDR_EL1:
3247 		*valp = read_cpuid_id();
3248 		break;
3249 	case SYS_MPIDR_EL1:
3250 		*valp = SYS_MPIDR_SAFE_VAL;
3251 		break;
3252 	case SYS_REVIDR_EL1:
3253 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
3254 		*valp = 0;
3255 		break;
3256 	default:
3257 		return -EINVAL;
3258 	}
3259 
3260 	return 0;
3261 }
3262 
3263 static int emulate_sys_reg(u32 id, u64 *valp)
3264 {
3265 	struct arm64_ftr_reg *regp;
3266 
3267 	if (!is_emulated(id))
3268 		return -EINVAL;
3269 
3270 	if (sys_reg_CRm(id) == 0)
3271 		return emulate_id_reg(id, valp);
3272 
3273 	regp = get_arm64_ftr_reg_nowarn(id);
3274 	if (regp)
3275 		*valp = arm64_ftr_reg_user_value(regp);
3276 	else
3277 		/*
3278 		 * The untracked registers are either IMPLEMENTATION DEFINED
3279 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
3280 		 */
3281 		*valp = 0;
3282 	return 0;
3283 }
3284 
3285 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
3286 {
3287 	int rc;
3288 	u64 val;
3289 
3290 	rc = emulate_sys_reg(sys_reg, &val);
3291 	if (!rc) {
3292 		pt_regs_write_reg(regs, rt, val);
3293 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
3294 	}
3295 	return rc;
3296 }
3297 
3298 static int emulate_mrs(struct pt_regs *regs, u32 insn)
3299 {
3300 	u32 sys_reg, rt;
3301 
3302 	/*
3303 	 * sys_reg values are defined as used in mrs/msr instruction.
3304 	 * shift the imm value to get the encoding.
3305 	 */
3306 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
3307 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
3308 	return do_emulate_mrs(regs, sys_reg, rt);
3309 }
3310 
3311 static struct undef_hook mrs_hook = {
3312 	.instr_mask = 0xffff0000,
3313 	.instr_val  = 0xd5380000,
3314 	.pstate_mask = PSR_AA32_MODE_MASK,
3315 	.pstate_val = PSR_MODE_EL0t,
3316 	.fn = emulate_mrs,
3317 };
3318 
3319 static int __init enable_mrs_emulation(void)
3320 {
3321 	register_undef_hook(&mrs_hook);
3322 	return 0;
3323 }
3324 
3325 core_initcall(enable_mrs_emulation);
3326 
3327 enum mitigation_state arm64_get_meltdown_state(void)
3328 {
3329 	if (__meltdown_safe)
3330 		return SPECTRE_UNAFFECTED;
3331 
3332 	if (arm64_kernel_unmapped_at_el0())
3333 		return SPECTRE_MITIGATED;
3334 
3335 	return SPECTRE_VULNERABLE;
3336 }
3337 
3338 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
3339 			  char *buf)
3340 {
3341 	switch (arm64_get_meltdown_state()) {
3342 	case SPECTRE_UNAFFECTED:
3343 		return sprintf(buf, "Not affected\n");
3344 
3345 	case SPECTRE_MITIGATED:
3346 		return sprintf(buf, "Mitigation: PTI\n");
3347 
3348 	default:
3349 		return sprintf(buf, "Vulnerable\n");
3350 	}
3351 }
3352