xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision c4f7ac64)
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/types.h>
71 #include <linux/minmax.h>
72 #include <linux/mm.h>
73 #include <linux/cpu.h>
74 #include <linux/kasan.h>
75 #include <asm/cpu.h>
76 #include <asm/cpufeature.h>
77 #include <asm/cpu_ops.h>
78 #include <asm/fpsimd.h>
79 #include <asm/kvm_host.h>
80 #include <asm/mmu_context.h>
81 #include <asm/mte.h>
82 #include <asm/processor.h>
83 #include <asm/sysreg.h>
84 #include <asm/traps.h>
85 #include <asm/virt.h>
86 
87 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
88 static unsigned long elf_hwcap __read_mostly;
89 
90 #ifdef CONFIG_COMPAT
91 #define COMPAT_ELF_HWCAP_DEFAULT	\
92 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
93 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
94 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\
95 				 COMPAT_HWCAP_LPAE)
96 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
97 unsigned int compat_elf_hwcap2 __read_mostly;
98 #endif
99 
100 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
101 EXPORT_SYMBOL(cpu_hwcaps);
102 static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
103 
104 /* Need also bit for ARM64_CB_PATCH */
105 DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
106 
107 bool arm64_use_ng_mappings = false;
108 EXPORT_SYMBOL(arm64_use_ng_mappings);
109 
110 /*
111  * Flag to indicate if we have computed the system wide
112  * capabilities based on the boot time active CPUs. This
113  * will be used to determine if a new booting CPU should
114  * go through the verification process to make sure that it
115  * supports the system capabilities, without using a hotplug
116  * notifier. This is also used to decide if we could use
117  * the fast path for checking constant CPU caps.
118  */
119 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
120 EXPORT_SYMBOL(arm64_const_caps_ready);
121 static inline void finalize_system_capabilities(void)
122 {
123 	static_branch_enable(&arm64_const_caps_ready);
124 }
125 
126 void dump_cpu_features(void)
127 {
128 	/* file-wide pr_fmt adds "CPU features: " prefix */
129 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
130 }
131 
132 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
133 EXPORT_SYMBOL(cpu_hwcap_keys);
134 
135 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
136 	{						\
137 		.sign = SIGNED,				\
138 		.visible = VISIBLE,			\
139 		.strict = STRICT,			\
140 		.type = TYPE,				\
141 		.shift = SHIFT,				\
142 		.width = WIDTH,				\
143 		.safe_val = SAFE_VAL,			\
144 	}
145 
146 /* Define a feature with unsigned values */
147 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
148 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
149 
150 /* Define a feature with a signed value */
151 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
152 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
153 
154 #define ARM64_FTR_END					\
155 	{						\
156 		.width = 0,				\
157 	}
158 
159 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
160 
161 static bool __system_matches_cap(unsigned int n);
162 
163 /*
164  * NOTE: Any changes to the visibility of features should be kept in
165  * sync with the documentation of the CPU feature register ABI.
166  */
167 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
168 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0),
169 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TLB_SHIFT, 4, 0),
170 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
171 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
172 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
173 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
174 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
175 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
176 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
177 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
178 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
179 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
180 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
181 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
182 	ARM64_FTR_END,
183 };
184 
185 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
186 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
187 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DGH_SHIFT, 4, 0),
188 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_BF16_SHIFT, 4, 0),
189 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SPECRES_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
192 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
193 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
194 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
195 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
196 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
197 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
198 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
199 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
200 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_API_SHIFT, 4, 0),
201 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
202 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_APA_SHIFT, 4, 0),
203 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
204 	ARM64_FTR_END,
205 };
206 
207 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
208 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
209 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
210 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
211 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_AMU_SHIFT, 4, 0),
212 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_MPAM_SHIFT, 4, 0),
213 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SEL2_SHIFT, 4, 0),
214 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
215 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
217 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
218 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
219 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
220 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
221 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
222 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
223 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
224 	ARM64_FTR_END,
225 };
226 
227 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
228 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
230 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
231 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MTE_SHIFT, 4, ID_AA64PFR1_MTE_NI),
232 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
233 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
234 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
235 	ARM64_FTR_END,
236 };
237 
238 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
239 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
240 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
241 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
242 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
243 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
244 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
245 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
246 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
247 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
248 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
249 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
250 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BF16_SHIFT, 4, 0),
251 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
252 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
253 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
254 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
255 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
256 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
257 	ARM64_FTR_END,
258 };
259 
260 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
261 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0),
262 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0),
263 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EXS_SHIFT, 4, 0),
264 	/*
265 	 * Page size not being supported at Stage-2 is not fatal. You
266 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
267 	 * your favourite nesting hypervisor.
268 	 *
269 	 * There is a small corner case where the hypervisor explicitly
270 	 * advertises a given granule size at Stage-2 (value 2) on some
271 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
272 	 * vCPUs. Although this is not forbidden by the architecture, it
273 	 * indicates that the hypervisor is being silly (or buggy).
274 	 *
275 	 * We make no effort to cope with this and pretend that if these
276 	 * fields are inconsistent across vCPUs, then it isn't worth
277 	 * trying to bring KVM up.
278 	 */
279 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
280 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
281 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
282 	/*
283 	 * We already refuse to boot CPUs that don't support our configured
284 	 * page size, so we can only detect mismatches for a page size other
285 	 * than the one we're currently using. Unfortunately, SoCs like this
286 	 * exist in the wild so, even though we don't like it, we'll have to go
287 	 * along with it and treat them as non-strict.
288 	 */
289 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
290 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
291 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
292 
293 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
294 	/* Linux shouldn't care about secure memory */
295 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
296 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
297 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
298 	/*
299 	 * Differing PARange is fine as long as all peripherals and memory are mapped
300 	 * within the minimum PARange of all CPUs
301 	 */
302 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
303 	ARM64_FTR_END,
304 };
305 
306 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
307 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_ETS_SHIFT, 4, 0),
308 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_TWED_SHIFT, 4, 0),
309 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_XNX_SHIFT, 4, 0),
310 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64MMFR1_SPECSEI_SHIFT, 4, 0),
311 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
312 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
313 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
314 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
315 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
316 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
317 	ARM64_FTR_END,
318 };
319 
320 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
321 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0),
322 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EVT_SHIFT, 4, 0),
323 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_BBM_SHIFT, 4, 0),
324 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0),
325 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
326 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IDS_SHIFT, 4, 0),
327 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
328 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_ST_SHIFT, 4, 0),
329 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_NV_SHIFT, 4, 0),
330 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CCIDX_SHIFT, 4, 0),
331 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
332 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
333 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
334 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
335 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
336 	ARM64_FTR_END,
337 };
338 
339 static const struct arm64_ftr_bits ftr_ctr[] = {
340 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
341 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
342 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
343 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
344 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
345 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
346 	/*
347 	 * Linux can handle differing I-cache policies. Userspace JITs will
348 	 * make use of *minLine.
349 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
350 	 */
351 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, CTR_L1IP_SHIFT, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
352 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
353 	ARM64_FTR_END,
354 };
355 
356 static struct arm64_ftr_override __ro_after_init no_override = { };
357 
358 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
359 	.name		= "SYS_CTR_EL0",
360 	.ftr_bits	= ftr_ctr,
361 	.override	= &no_override,
362 };
363 
364 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
365 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_INNERSHR_SHIFT, 4, 0xf),
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_FCSE_SHIFT, 4, 0),
367 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_AUXREG_SHIFT, 4, 0),
368 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_TCM_SHIFT, 4, 0),
369 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_SHARELVL_SHIFT, 4, 0),
370 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_OUTERSHR_SHIFT, 4, 0xf),
371 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_PMSA_SHIFT, 4, 0),
372 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_VMSA_SHIFT, 4, 0),
373 	ARM64_FTR_END,
374 };
375 
376 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
377 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_DOUBLELOCK_SHIFT, 4, 0),
378 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
379 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
380 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
381 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
382 	/*
383 	 * We can instantiate multiple PMU instances with different levels
384 	 * of support.
385 	 */
386 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
387 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
388 	ARM64_FTR_END,
389 };
390 
391 static const struct arm64_ftr_bits ftr_mvfr2[] = {
392 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_FPMISC_SHIFT, 4, 0),
393 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_SIMDMISC_SHIFT, 4, 0),
394 	ARM64_FTR_END,
395 };
396 
397 static const struct arm64_ftr_bits ftr_dczid[] = {
398 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_DZP_SHIFT, 1, 1),
399 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_BS_SHIFT, 4, 0),
400 	ARM64_FTR_END,
401 };
402 
403 static const struct arm64_ftr_bits ftr_id_isar0[] = {
404 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
405 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
406 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
407 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
408 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
409 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
410 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
411 	ARM64_FTR_END,
412 };
413 
414 static const struct arm64_ftr_bits ftr_id_isar5[] = {
415 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
416 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
417 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
418 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
419 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
420 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
421 	ARM64_FTR_END,
422 };
423 
424 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
427 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
428 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
429 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
430 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
431 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_AC2_SHIFT, 4, 0),
432 
433 	/*
434 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
435 	 * external abort on speculative read. It is safe to assume that an
436 	 * SError might be generated than it will not be. Hence it has been
437 	 * classified as FTR_HIGHER_SAFE.
438 	 */
439 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
440 	ARM64_FTR_END,
441 };
442 
443 static const struct arm64_ftr_bits ftr_id_isar4[] = {
444 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
446 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
447 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
448 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
449 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
450 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
451 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
452 	ARM64_FTR_END,
453 };
454 
455 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
456 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
457 	ARM64_FTR_END,
458 };
459 
460 static const struct arm64_ftr_bits ftr_id_isar6[] = {
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
463 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
464 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
465 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
466 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
467 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
468 	ARM64_FTR_END,
469 };
470 
471 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
472 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
474 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE3_SHIFT, 4, 0),
475 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE2_SHIFT, 4, 0),
476 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE1_SHIFT, 4, 0),
477 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE0_SHIFT, 4, 0),
478 	ARM64_FTR_END,
479 };
480 
481 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
484 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
485 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
486 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
487 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
488 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
489 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
490 	ARM64_FTR_END,
491 };
492 
493 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
494 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
495 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
496 	ARM64_FTR_END,
497 };
498 
499 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
500 	/* [31:28] TraceFilt */
501 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_PERFMON_SHIFT, 4, 0xf),
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MPROFDBG_SHIFT, 4, 0),
503 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPTRC_SHIFT, 4, 0),
504 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPTRC_SHIFT, 4, 0),
505 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPDBG_SHIFT, 4, 0),
506 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPSDBG_SHIFT, 4, 0),
507 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPDBG_SHIFT, 4, 0),
508 	ARM64_FTR_END,
509 };
510 
511 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
512 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
513 	ARM64_FTR_END,
514 };
515 
516 static const struct arm64_ftr_bits ftr_zcr[] = {
517 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
518 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
519 	ARM64_FTR_END,
520 };
521 
522 /*
523  * Common ftr bits for a 32bit register with all hidden, strict
524  * attributes, with 4bit feature fields and a default safe value of
525  * 0. Covers the following 32bit registers:
526  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
527  */
528 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
531 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
532 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
533 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
534 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
535 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
536 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
537 	ARM64_FTR_END,
538 };
539 
540 /* Table for a single 32bit feature value */
541 static const struct arm64_ftr_bits ftr_single32[] = {
542 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
543 	ARM64_FTR_END,
544 };
545 
546 static const struct arm64_ftr_bits ftr_raz[] = {
547 	ARM64_FTR_END,
548 };
549 
550 #define ARM64_FTR_REG_OVERRIDE(id, table, ovr) {		\
551 		.sys_id = id,					\
552 		.reg = 	&(struct arm64_ftr_reg){		\
553 			.name = #id,				\
554 			.override = (ovr),			\
555 			.ftr_bits = &((table)[0]),		\
556 	}}
557 
558 #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, &no_override)
559 
560 struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override;
561 struct arm64_ftr_override __ro_after_init id_aa64pfr1_override;
562 struct arm64_ftr_override __ro_after_init id_aa64isar1_override;
563 
564 static const struct __ftr_reg_entry {
565 	u32			sys_id;
566 	struct arm64_ftr_reg 	*reg;
567 } arm64_ftr_regs[] = {
568 
569 	/* Op1 = 0, CRn = 0, CRm = 1 */
570 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
571 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
572 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
573 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
574 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
575 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
576 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
577 
578 	/* Op1 = 0, CRn = 0, CRm = 2 */
579 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
580 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
581 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
582 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
583 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
584 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
585 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
586 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
587 
588 	/* Op1 = 0, CRn = 0, CRm = 3 */
589 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
590 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
591 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
592 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
593 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
594 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
595 
596 	/* Op1 = 0, CRn = 0, CRm = 4 */
597 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
598 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1,
599 			       &id_aa64pfr1_override),
600 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
601 
602 	/* Op1 = 0, CRn = 0, CRm = 5 */
603 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
604 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
605 
606 	/* Op1 = 0, CRn = 0, CRm = 6 */
607 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
608 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1,
609 			       &id_aa64isar1_override),
610 
611 	/* Op1 = 0, CRn = 0, CRm = 7 */
612 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
613 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1,
614 			       &id_aa64mmfr1_override),
615 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
616 
617 	/* Op1 = 0, CRn = 1, CRm = 2 */
618 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
619 
620 	/* Op1 = 3, CRn = 0, CRm = 0 */
621 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
622 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
623 
624 	/* Op1 = 3, CRn = 14, CRm = 0 */
625 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
626 };
627 
628 static int search_cmp_ftr_reg(const void *id, const void *regp)
629 {
630 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
631 }
632 
633 /*
634  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
635  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
636  * ascending order of sys_id, we use binary search to find a matching
637  * entry.
638  *
639  * returns - Upon success,  matching ftr_reg entry for id.
640  *         - NULL on failure. It is upto the caller to decide
641  *	     the impact of a failure.
642  */
643 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
644 {
645 	const struct __ftr_reg_entry *ret;
646 
647 	ret = bsearch((const void *)(unsigned long)sys_id,
648 			arm64_ftr_regs,
649 			ARRAY_SIZE(arm64_ftr_regs),
650 			sizeof(arm64_ftr_regs[0]),
651 			search_cmp_ftr_reg);
652 	if (ret)
653 		return ret->reg;
654 	return NULL;
655 }
656 
657 /*
658  * get_arm64_ftr_reg - Looks up a feature register entry using
659  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
660  *
661  * returns - Upon success,  matching ftr_reg entry for id.
662  *         - NULL on failure but with an WARN_ON().
663  */
664 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
665 {
666 	struct arm64_ftr_reg *reg;
667 
668 	reg = get_arm64_ftr_reg_nowarn(sys_id);
669 
670 	/*
671 	 * Requesting a non-existent register search is an error. Warn
672 	 * and let the caller handle it.
673 	 */
674 	WARN_ON(!reg);
675 	return reg;
676 }
677 
678 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
679 			       s64 ftr_val)
680 {
681 	u64 mask = arm64_ftr_mask(ftrp);
682 
683 	reg &= ~mask;
684 	reg |= (ftr_val << ftrp->shift) & mask;
685 	return reg;
686 }
687 
688 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
689 				s64 cur)
690 {
691 	s64 ret = 0;
692 
693 	switch (ftrp->type) {
694 	case FTR_EXACT:
695 		ret = ftrp->safe_val;
696 		break;
697 	case FTR_LOWER_SAFE:
698 		ret = min(new, cur);
699 		break;
700 	case FTR_HIGHER_OR_ZERO_SAFE:
701 		if (!cur || !new)
702 			break;
703 		fallthrough;
704 	case FTR_HIGHER_SAFE:
705 		ret = max(new, cur);
706 		break;
707 	default:
708 		BUG();
709 	}
710 
711 	return ret;
712 }
713 
714 static void __init sort_ftr_regs(void)
715 {
716 	unsigned int i;
717 
718 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
719 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
720 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
721 		unsigned int j = 0;
722 
723 		/*
724 		 * Features here must be sorted in descending order with respect
725 		 * to their shift values and should not overlap with each other.
726 		 */
727 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
728 			unsigned int width = ftr_reg->ftr_bits[j].width;
729 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
730 			unsigned int prev_shift;
731 
732 			WARN((shift  + width) > 64,
733 				"%s has invalid feature at shift %d\n",
734 				ftr_reg->name, shift);
735 
736 			/*
737 			 * Skip the first feature. There is nothing to
738 			 * compare against for now.
739 			 */
740 			if (j == 0)
741 				continue;
742 
743 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
744 			WARN((shift + width) > prev_shift,
745 				"%s has feature overlap at shift %d\n",
746 				ftr_reg->name, shift);
747 		}
748 
749 		/*
750 		 * Skip the first register. There is nothing to
751 		 * compare against for now.
752 		 */
753 		if (i == 0)
754 			continue;
755 		/*
756 		 * Registers here must be sorted in ascending order with respect
757 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
758 		 * to work correctly.
759 		 */
760 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
761 	}
762 }
763 
764 /*
765  * Initialise the CPU feature register from Boot CPU values.
766  * Also initiliases the strict_mask for the register.
767  * Any bits that are not covered by an arm64_ftr_bits entry are considered
768  * RES0 for the system-wide value, and must strictly match.
769  */
770 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
771 {
772 	u64 val = 0;
773 	u64 strict_mask = ~0x0ULL;
774 	u64 user_mask = 0;
775 	u64 valid_mask = 0;
776 
777 	const struct arm64_ftr_bits *ftrp;
778 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
779 
780 	if (!reg)
781 		return;
782 
783 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
784 		u64 ftr_mask = arm64_ftr_mask(ftrp);
785 		s64 ftr_new = arm64_ftr_value(ftrp, new);
786 		s64 ftr_ovr = arm64_ftr_value(ftrp, reg->override->val);
787 
788 		if ((ftr_mask & reg->override->mask) == ftr_mask) {
789 			s64 tmp = arm64_ftr_safe_value(ftrp, ftr_ovr, ftr_new);
790 			char *str = NULL;
791 
792 			if (ftr_ovr != tmp) {
793 				/* Unsafe, remove the override */
794 				reg->override->mask &= ~ftr_mask;
795 				reg->override->val &= ~ftr_mask;
796 				tmp = ftr_ovr;
797 				str = "ignoring override";
798 			} else if (ftr_new != tmp) {
799 				/* Override was valid */
800 				ftr_new = tmp;
801 				str = "forced";
802 			} else if (ftr_ovr == tmp) {
803 				/* Override was the safe value */
804 				str = "already set";
805 			}
806 
807 			if (str)
808 				pr_warn("%s[%d:%d]: %s to %llx\n",
809 					reg->name,
810 					ftrp->shift + ftrp->width - 1,
811 					ftrp->shift, str, tmp);
812 		} else if ((ftr_mask & reg->override->val) == ftr_mask) {
813 			reg->override->val &= ~ftr_mask;
814 			pr_warn("%s[%d:%d]: impossible override, ignored\n",
815 				reg->name,
816 				ftrp->shift + ftrp->width - 1,
817 				ftrp->shift);
818 		}
819 
820 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
821 
822 		valid_mask |= ftr_mask;
823 		if (!ftrp->strict)
824 			strict_mask &= ~ftr_mask;
825 		if (ftrp->visible)
826 			user_mask |= ftr_mask;
827 		else
828 			reg->user_val = arm64_ftr_set_value(ftrp,
829 							    reg->user_val,
830 							    ftrp->safe_val);
831 	}
832 
833 	val &= valid_mask;
834 
835 	reg->sys_val = val;
836 	reg->strict_mask = strict_mask;
837 	reg->user_mask = user_mask;
838 }
839 
840 extern const struct arm64_cpu_capabilities arm64_errata[];
841 static const struct arm64_cpu_capabilities arm64_features[];
842 
843 static void __init
844 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
845 {
846 	for (; caps->matches; caps++) {
847 		if (WARN(caps->capability >= ARM64_NCAPS,
848 			"Invalid capability %d\n", caps->capability))
849 			continue;
850 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
851 			"Duplicate entry for capability %d\n",
852 			caps->capability))
853 			continue;
854 		cpu_hwcaps_ptrs[caps->capability] = caps;
855 	}
856 }
857 
858 static void __init init_cpu_hwcaps_indirect_list(void)
859 {
860 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
861 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
862 }
863 
864 static void __init setup_boot_cpu_capabilities(void);
865 
866 void __init init_cpu_features(struct cpuinfo_arm64 *info)
867 {
868 	/* Before we start using the tables, make sure it is sorted */
869 	sort_ftr_regs();
870 
871 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
872 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
873 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
874 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
875 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
876 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
877 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
878 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
879 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
880 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
881 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
882 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
883 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
884 
885 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
886 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
887 		init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
888 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
889 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
890 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
891 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
892 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
893 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
894 		init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
895 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
896 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
897 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
898 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
899 		init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
900 		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
901 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
902 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
903 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
904 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
905 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
906 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
907 	}
908 
909 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
910 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
911 		sve_init_vq_map();
912 	}
913 
914 	/*
915 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
916 	 * before we handle the boot CPU below.
917 	 */
918 	init_cpu_hwcaps_indirect_list();
919 
920 	/*
921 	 * Detect and enable early CPU capabilities based on the boot CPU,
922 	 * after we have initialised the CPU feature infrastructure.
923 	 */
924 	setup_boot_cpu_capabilities();
925 }
926 
927 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
928 {
929 	const struct arm64_ftr_bits *ftrp;
930 
931 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
932 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
933 		s64 ftr_new = arm64_ftr_value(ftrp, new);
934 
935 		if (ftr_cur == ftr_new)
936 			continue;
937 		/* Find a safe value */
938 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
939 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
940 	}
941 
942 }
943 
944 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
945 {
946 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
947 
948 	if (!regp)
949 		return 0;
950 
951 	update_cpu_ftr_reg(regp, val);
952 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
953 		return 0;
954 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
955 			regp->name, boot, cpu, val);
956 	return 1;
957 }
958 
959 static void relax_cpu_ftr_reg(u32 sys_id, int field)
960 {
961 	const struct arm64_ftr_bits *ftrp;
962 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
963 
964 	if (!regp)
965 		return;
966 
967 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
968 		if (ftrp->shift == field) {
969 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
970 			break;
971 		}
972 	}
973 
974 	/* Bogus field? */
975 	WARN_ON(!ftrp->width);
976 }
977 
978 static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
979 				     struct cpuinfo_arm64 *boot)
980 {
981 	int taint = 0;
982 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
983 
984 	/*
985 	 * If we don't have AArch32 at all then skip the checks entirely
986 	 * as the register values may be UNKNOWN and we're not going to be
987 	 * using them for anything.
988 	 */
989 	if (!id_aa64pfr0_32bit_el0(pfr0))
990 		return taint;
991 
992 	/*
993 	 * If we don't have AArch32 at EL1, then relax the strictness of
994 	 * EL1-dependent register fields to avoid spurious sanity check fails.
995 	 */
996 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
997 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
998 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
999 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
1000 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
1001 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
1002 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
1003 	}
1004 
1005 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
1006 				      info->reg_id_dfr0, boot->reg_id_dfr0);
1007 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
1008 				      info->reg_id_dfr1, boot->reg_id_dfr1);
1009 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
1010 				      info->reg_id_isar0, boot->reg_id_isar0);
1011 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
1012 				      info->reg_id_isar1, boot->reg_id_isar1);
1013 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
1014 				      info->reg_id_isar2, boot->reg_id_isar2);
1015 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
1016 				      info->reg_id_isar3, boot->reg_id_isar3);
1017 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
1018 				      info->reg_id_isar4, boot->reg_id_isar4);
1019 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
1020 				      info->reg_id_isar5, boot->reg_id_isar5);
1021 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
1022 				      info->reg_id_isar6, boot->reg_id_isar6);
1023 
1024 	/*
1025 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
1026 	 * ACTLR formats could differ across CPUs and therefore would have to
1027 	 * be trapped for virtualization anyway.
1028 	 */
1029 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
1030 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
1031 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
1032 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
1033 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
1034 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
1035 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
1036 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
1037 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
1038 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
1039 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
1040 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
1041 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
1042 				      info->reg_id_pfr0, boot->reg_id_pfr0);
1043 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
1044 				      info->reg_id_pfr1, boot->reg_id_pfr1);
1045 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
1046 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1047 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1048 				      info->reg_mvfr0, boot->reg_mvfr0);
1049 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1050 				      info->reg_mvfr1, boot->reg_mvfr1);
1051 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1052 				      info->reg_mvfr2, boot->reg_mvfr2);
1053 
1054 	return taint;
1055 }
1056 
1057 /*
1058  * Update system wide CPU feature registers with the values from a
1059  * non-boot CPU. Also performs SANITY checks to make sure that there
1060  * aren't any insane variations from that of the boot CPU.
1061  */
1062 void update_cpu_features(int cpu,
1063 			 struct cpuinfo_arm64 *info,
1064 			 struct cpuinfo_arm64 *boot)
1065 {
1066 	int taint = 0;
1067 
1068 	/*
1069 	 * The kernel can handle differing I-cache policies, but otherwise
1070 	 * caches should look identical. Userspace JITs will make use of
1071 	 * *minLine.
1072 	 */
1073 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1074 				      info->reg_ctr, boot->reg_ctr);
1075 
1076 	/*
1077 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1078 	 * could result in too much or too little memory being zeroed if a
1079 	 * process is preempted and migrated between CPUs.
1080 	 */
1081 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1082 				      info->reg_dczid, boot->reg_dczid);
1083 
1084 	/* If different, timekeeping will be broken (especially with KVM) */
1085 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1086 				      info->reg_cntfrq, boot->reg_cntfrq);
1087 
1088 	/*
1089 	 * The kernel uses self-hosted debug features and expects CPUs to
1090 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1091 	 * and BRPs to be identical.
1092 	 * ID_AA64DFR1 is currently RES0.
1093 	 */
1094 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1095 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1096 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1097 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1098 	/*
1099 	 * Even in big.LITTLE, processors should be identical instruction-set
1100 	 * wise.
1101 	 */
1102 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1103 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1104 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1105 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1106 
1107 	/*
1108 	 * Differing PARange support is fine as long as all peripherals and
1109 	 * memory are mapped within the minimum PARange of all CPUs.
1110 	 * Linux should not care about secure memory.
1111 	 */
1112 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1113 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1114 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1115 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1116 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1117 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1118 
1119 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1120 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1121 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1122 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1123 
1124 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1125 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1126 
1127 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1128 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1129 					info->reg_zcr, boot->reg_zcr);
1130 
1131 		/* Probe vector lengths, unless we already gave up on SVE */
1132 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1133 		    !system_capabilities_finalized())
1134 			sve_update_vq_map();
1135 	}
1136 
1137 	/*
1138 	 * This relies on a sanitised view of the AArch64 ID registers
1139 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1140 	 */
1141 	taint |= update_32bit_cpu_features(cpu, info, boot);
1142 
1143 	/*
1144 	 * Mismatched CPU features are a recipe for disaster. Don't even
1145 	 * pretend to support them.
1146 	 */
1147 	if (taint) {
1148 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1149 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1150 	}
1151 }
1152 
1153 u64 read_sanitised_ftr_reg(u32 id)
1154 {
1155 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1156 
1157 	if (!regp)
1158 		return 0;
1159 	return regp->sys_val;
1160 }
1161 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
1162 
1163 #define read_sysreg_case(r)	\
1164 	case r:		val = read_sysreg_s(r); break;
1165 
1166 /*
1167  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1168  * Read the system register on the current CPU
1169  */
1170 u64 __read_sysreg_by_encoding(u32 sys_id)
1171 {
1172 	struct arm64_ftr_reg *regp;
1173 	u64 val;
1174 
1175 	switch (sys_id) {
1176 	read_sysreg_case(SYS_ID_PFR0_EL1);
1177 	read_sysreg_case(SYS_ID_PFR1_EL1);
1178 	read_sysreg_case(SYS_ID_PFR2_EL1);
1179 	read_sysreg_case(SYS_ID_DFR0_EL1);
1180 	read_sysreg_case(SYS_ID_DFR1_EL1);
1181 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1182 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1183 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1184 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1185 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1186 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1187 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1188 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1189 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1190 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1191 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1192 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1193 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1194 	read_sysreg_case(SYS_MVFR0_EL1);
1195 	read_sysreg_case(SYS_MVFR1_EL1);
1196 	read_sysreg_case(SYS_MVFR2_EL1);
1197 
1198 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1199 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1200 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1201 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1202 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1203 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1204 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1205 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1206 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1207 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1208 
1209 	read_sysreg_case(SYS_CNTFRQ_EL0);
1210 	read_sysreg_case(SYS_CTR_EL0);
1211 	read_sysreg_case(SYS_DCZID_EL0);
1212 
1213 	default:
1214 		BUG();
1215 		return 0;
1216 	}
1217 
1218 	regp  = get_arm64_ftr_reg(sys_id);
1219 	if (regp) {
1220 		val &= ~regp->override->mask;
1221 		val |= (regp->override->val & regp->override->mask);
1222 	}
1223 
1224 	return val;
1225 }
1226 
1227 #include <linux/irqchip/arm-gic-v3.h>
1228 
1229 static bool
1230 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1231 {
1232 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
1233 
1234 	return val >= entry->min_field_value;
1235 }
1236 
1237 static bool
1238 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1239 {
1240 	u64 val;
1241 
1242 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1243 	if (scope == SCOPE_SYSTEM)
1244 		val = read_sanitised_ftr_reg(entry->sys_reg);
1245 	else
1246 		val = __read_sysreg_by_encoding(entry->sys_reg);
1247 
1248 	return feature_matches(val, entry);
1249 }
1250 
1251 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1252 {
1253 	bool has_sre;
1254 
1255 	if (!has_cpuid_feature(entry, scope))
1256 		return false;
1257 
1258 	has_sre = gic_enable_sre();
1259 	if (!has_sre)
1260 		pr_warn_once("%s present but disabled by higher exception level\n",
1261 			     entry->desc);
1262 
1263 	return has_sre;
1264 }
1265 
1266 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1267 {
1268 	u32 midr = read_cpuid_id();
1269 
1270 	/* Cavium ThunderX pass 1.x and 2.x */
1271 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1272 		MIDR_CPU_VAR_REV(0, 0),
1273 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1274 }
1275 
1276 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1277 {
1278 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1279 
1280 	return cpuid_feature_extract_signed_field(pfr0,
1281 					ID_AA64PFR0_FP_SHIFT) < 0;
1282 }
1283 
1284 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1285 			  int scope)
1286 {
1287 	u64 ctr;
1288 
1289 	if (scope == SCOPE_SYSTEM)
1290 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1291 	else
1292 		ctr = read_cpuid_effective_cachetype();
1293 
1294 	return ctr & BIT(CTR_IDC_SHIFT);
1295 }
1296 
1297 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1298 {
1299 	/*
1300 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1301 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1302 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1303 	 * value.
1304 	 */
1305 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1306 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1307 }
1308 
1309 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1310 			  int scope)
1311 {
1312 	u64 ctr;
1313 
1314 	if (scope == SCOPE_SYSTEM)
1315 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1316 	else
1317 		ctr = read_cpuid_cachetype();
1318 
1319 	return ctr & BIT(CTR_DIC_SHIFT);
1320 }
1321 
1322 static bool __maybe_unused
1323 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1324 {
1325 	/*
1326 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1327 	 * may share TLB entries with a CPU stuck in the crashed
1328 	 * kernel.
1329 	 */
1330 	if (is_kdump_kernel())
1331 		return false;
1332 
1333 	if (cpus_have_const_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
1334 		return false;
1335 
1336 	return has_cpuid_feature(entry, scope);
1337 }
1338 
1339 /*
1340  * This check is triggered during the early boot before the cpufeature
1341  * is initialised. Checking the status on the local CPU allows the boot
1342  * CPU to detect the need for non-global mappings and thus avoiding a
1343  * pagetable re-write after all the CPUs are booted. This check will be
1344  * anyway run on individual CPUs, allowing us to get the consistent
1345  * state once the SMP CPUs are up and thus make the switch to non-global
1346  * mappings if required.
1347  */
1348 bool kaslr_requires_kpti(void)
1349 {
1350 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1351 		return false;
1352 
1353 	/*
1354 	 * E0PD does a similar job to KPTI so can be used instead
1355 	 * where available.
1356 	 */
1357 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1358 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1359 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1360 						ID_AA64MMFR2_E0PD_SHIFT))
1361 			return false;
1362 	}
1363 
1364 	/*
1365 	 * Systems affected by Cavium erratum 24756 are incompatible
1366 	 * with KPTI.
1367 	 */
1368 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1369 		extern const struct midr_range cavium_erratum_27456_cpus[];
1370 
1371 		if (is_midr_in_range_list(read_cpuid_id(),
1372 					  cavium_erratum_27456_cpus))
1373 			return false;
1374 	}
1375 
1376 	return kaslr_offset() > 0;
1377 }
1378 
1379 static bool __meltdown_safe = true;
1380 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1381 
1382 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1383 				int scope)
1384 {
1385 	/* List of CPUs that are not vulnerable and don't need KPTI */
1386 	static const struct midr_range kpti_safe_list[] = {
1387 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1388 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1389 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1390 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1391 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1392 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1393 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1394 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1395 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1396 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1397 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1398 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_GOLD),
1399 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
1400 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1401 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1402 		{ /* sentinel */ }
1403 	};
1404 	char const *str = "kpti command line option";
1405 	bool meltdown_safe;
1406 
1407 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1408 
1409 	/* Defer to CPU feature registers */
1410 	if (has_cpuid_feature(entry, scope))
1411 		meltdown_safe = true;
1412 
1413 	if (!meltdown_safe)
1414 		__meltdown_safe = false;
1415 
1416 	/*
1417 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1418 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1419 	 * ends as well as you might imagine. Don't even try.
1420 	 */
1421 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1422 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1423 		__kpti_forced = -1;
1424 	}
1425 
1426 	/* Useful for KASLR robustness */
1427 	if (kaslr_requires_kpti()) {
1428 		if (!__kpti_forced) {
1429 			str = "KASLR";
1430 			__kpti_forced = 1;
1431 		}
1432 	}
1433 
1434 	if (cpu_mitigations_off() && !__kpti_forced) {
1435 		str = "mitigations=off";
1436 		__kpti_forced = -1;
1437 	}
1438 
1439 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1440 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1441 		return false;
1442 	}
1443 
1444 	/* Forced? */
1445 	if (__kpti_forced) {
1446 		pr_info_once("kernel page table isolation forced %s by %s\n",
1447 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1448 		return __kpti_forced > 0;
1449 	}
1450 
1451 	return !meltdown_safe;
1452 }
1453 
1454 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1455 static void __nocfi
1456 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1457 {
1458 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1459 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1460 	kpti_remap_fn *remap_fn;
1461 
1462 	int cpu = smp_processor_id();
1463 
1464 	/*
1465 	 * We don't need to rewrite the page-tables if either we've done
1466 	 * it already or we have KASLR enabled and therefore have not
1467 	 * created any global mappings at all.
1468 	 */
1469 	if (arm64_use_ng_mappings)
1470 		return;
1471 
1472 	remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));
1473 
1474 	cpu_install_idmap();
1475 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1476 	cpu_uninstall_idmap();
1477 
1478 	if (!cpu)
1479 		arm64_use_ng_mappings = true;
1480 
1481 	return;
1482 }
1483 #else
1484 static void
1485 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1486 {
1487 }
1488 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1489 
1490 static int __init parse_kpti(char *str)
1491 {
1492 	bool enabled;
1493 	int ret = strtobool(str, &enabled);
1494 
1495 	if (ret)
1496 		return ret;
1497 
1498 	__kpti_forced = enabled ? 1 : -1;
1499 	return 0;
1500 }
1501 early_param("kpti", parse_kpti);
1502 
1503 #ifdef CONFIG_ARM64_HW_AFDBM
1504 static inline void __cpu_enable_hw_dbm(void)
1505 {
1506 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1507 
1508 	write_sysreg(tcr, tcr_el1);
1509 	isb();
1510 	local_flush_tlb_all();
1511 }
1512 
1513 static bool cpu_has_broken_dbm(void)
1514 {
1515 	/* List of CPUs which have broken DBM support. */
1516 	static const struct midr_range cpus[] = {
1517 #ifdef CONFIG_ARM64_ERRATUM_1024718
1518 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1519 		/* Kryo4xx Silver (rdpe => r1p0) */
1520 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1521 #endif
1522 		{},
1523 	};
1524 
1525 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1526 }
1527 
1528 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1529 {
1530 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1531 	       !cpu_has_broken_dbm();
1532 }
1533 
1534 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1535 {
1536 	if (cpu_can_use_dbm(cap))
1537 		__cpu_enable_hw_dbm();
1538 }
1539 
1540 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1541 		       int __unused)
1542 {
1543 	static bool detected = false;
1544 	/*
1545 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1546 	 * run a mix of CPUs with and without the feature. So, we
1547 	 * unconditionally enable the capability to allow any late CPU
1548 	 * to use the feature. We only enable the control bits on the
1549 	 * CPU, if it actually supports.
1550 	 *
1551 	 * We have to make sure we print the "feature" detection only
1552 	 * when at least one CPU actually uses it. So check if this CPU
1553 	 * can actually use it and print the message exactly once.
1554 	 *
1555 	 * This is safe as all CPUs (including secondary CPUs - due to the
1556 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1557 	 * goes through the "matches" check exactly once. Also if a CPU
1558 	 * matches the criteria, it is guaranteed that the CPU will turn
1559 	 * the DBM on, as the capability is unconditionally enabled.
1560 	 */
1561 	if (!detected && cpu_can_use_dbm(cap)) {
1562 		detected = true;
1563 		pr_info("detected: Hardware dirty bit management\n");
1564 	}
1565 
1566 	return true;
1567 }
1568 
1569 #endif
1570 
1571 #ifdef CONFIG_ARM64_AMU_EXTN
1572 
1573 /*
1574  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1575  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1576  * information regarding all the events that it supports. When a CPU bit is
1577  * set in the cpumask, the user of this feature can only rely on the presence
1578  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1579  * counters are enabled or access to these counters is enabled by code
1580  * executed at higher exception levels (firmware).
1581  */
1582 static struct cpumask amu_cpus __read_mostly;
1583 
1584 bool cpu_has_amu_feat(int cpu)
1585 {
1586 	return cpumask_test_cpu(cpu, &amu_cpus);
1587 }
1588 
1589 int get_cpu_with_amu_feat(void)
1590 {
1591 	return cpumask_any(&amu_cpus);
1592 }
1593 
1594 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1595 {
1596 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1597 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1598 			smp_processor_id());
1599 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1600 		update_freq_counters_refs();
1601 	}
1602 }
1603 
1604 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1605 		    int __unused)
1606 {
1607 	/*
1608 	 * The AMU extension is a non-conflicting feature: the kernel can
1609 	 * safely run a mix of CPUs with and without support for the
1610 	 * activity monitors extension. Therefore, unconditionally enable
1611 	 * the capability to allow any late CPU to use the feature.
1612 	 *
1613 	 * With this feature unconditionally enabled, the cpu_enable
1614 	 * function will be called for all CPUs that match the criteria,
1615 	 * including secondary and hotplugged, marking this feature as
1616 	 * present on that respective CPU. The enable function will also
1617 	 * print a detection message.
1618 	 */
1619 
1620 	return true;
1621 }
1622 #else
1623 int get_cpu_with_amu_feat(void)
1624 {
1625 	return nr_cpu_ids;
1626 }
1627 #endif
1628 
1629 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1630 {
1631 	return is_kernel_in_hyp_mode();
1632 }
1633 
1634 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1635 {
1636 	/*
1637 	 * Copy register values that aren't redirected by hardware.
1638 	 *
1639 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1640 	 * this value to tpidr_el2 before we patch the code. Once we've done
1641 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1642 	 * do anything here.
1643 	 */
1644 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1645 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1646 }
1647 
1648 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1649 {
1650 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1651 
1652 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1653 	WARN_ON(val & (7 << 27 | 7 << 21));
1654 }
1655 
1656 #ifdef CONFIG_ARM64_PAN
1657 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1658 {
1659 	/*
1660 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1661 	 * is discarded once we return from the exception.
1662 	 */
1663 	WARN_ON_ONCE(in_interrupt());
1664 
1665 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1666 	set_pstate_pan(1);
1667 }
1668 #endif /* CONFIG_ARM64_PAN */
1669 
1670 #ifdef CONFIG_ARM64_RAS_EXTN
1671 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1672 {
1673 	/* Firmware may have left a deferred SError in this register. */
1674 	write_sysreg_s(0, SYS_DISR_EL1);
1675 }
1676 #endif /* CONFIG_ARM64_RAS_EXTN */
1677 
1678 #ifdef CONFIG_ARM64_PTR_AUTH
1679 static bool has_address_auth_cpucap(const struct arm64_cpu_capabilities *entry, int scope)
1680 {
1681 	int boot_val, sec_val;
1682 
1683 	/* We don't expect to be called with SCOPE_SYSTEM */
1684 	WARN_ON(scope == SCOPE_SYSTEM);
1685 	/*
1686 	 * The ptr-auth feature levels are not intercompatible with lower
1687 	 * levels. Hence we must match ptr-auth feature level of the secondary
1688 	 * CPUs with that of the boot CPU. The level of boot cpu is fetched
1689 	 * from the sanitised register whereas direct register read is done for
1690 	 * the secondary CPUs.
1691 	 * The sanitised feature state is guaranteed to match that of the
1692 	 * boot CPU as a mismatched secondary CPU is parked before it gets
1693 	 * a chance to update the state, with the capability.
1694 	 */
1695 	boot_val = cpuid_feature_extract_field(read_sanitised_ftr_reg(entry->sys_reg),
1696 					       entry->field_pos, entry->sign);
1697 	if (scope & SCOPE_BOOT_CPU)
1698 		return boot_val >= entry->min_field_value;
1699 	/* Now check for the secondary CPUs with SCOPE_LOCAL_CPU scope */
1700 	sec_val = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg),
1701 					      entry->field_pos, entry->sign);
1702 	return sec_val == boot_val;
1703 }
1704 
1705 static bool has_address_auth_metacap(const struct arm64_cpu_capabilities *entry,
1706 				     int scope)
1707 {
1708 	return has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH], scope) ||
1709 	       has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_IMP_DEF], scope);
1710 }
1711 
1712 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1713 			     int __unused)
1714 {
1715 	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
1716 	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1717 }
1718 #endif /* CONFIG_ARM64_PTR_AUTH */
1719 
1720 #ifdef CONFIG_ARM64_E0PD
1721 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1722 {
1723 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1724 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1725 }
1726 #endif /* CONFIG_ARM64_E0PD */
1727 
1728 #ifdef CONFIG_ARM64_PSEUDO_NMI
1729 static bool enable_pseudo_nmi;
1730 
1731 static int __init early_enable_pseudo_nmi(char *p)
1732 {
1733 	return strtobool(p, &enable_pseudo_nmi);
1734 }
1735 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1736 
1737 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1738 				   int scope)
1739 {
1740 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1741 }
1742 #endif
1743 
1744 #ifdef CONFIG_ARM64_BTI
1745 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1746 {
1747 	/*
1748 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1749 	 * function entry points using BR is a requirement for
1750 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1751 	 * So, be strict and forbid other BRs using other registers to
1752 	 * jump onto a PACIxSP instruction:
1753 	 */
1754 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1755 	isb();
1756 }
1757 #endif /* CONFIG_ARM64_BTI */
1758 
1759 #ifdef CONFIG_ARM64_MTE
1760 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
1761 {
1762 	/*
1763 	 * Clear the tags in the zero page. This needs to be done via the
1764 	 * linear map which has the Tagged attribute.
1765 	 */
1766 	if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
1767 		mte_clear_page_tags(lm_alias(empty_zero_page));
1768 
1769 	kasan_init_hw_tags_cpu();
1770 }
1771 #endif /* CONFIG_ARM64_MTE */
1772 
1773 #ifdef CONFIG_KVM
1774 static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
1775 {
1776 	if (kvm_get_mode() != KVM_MODE_PROTECTED)
1777 		return false;
1778 
1779 	if (is_kernel_in_hyp_mode()) {
1780 		pr_warn("Protected KVM not available with VHE\n");
1781 		return false;
1782 	}
1783 
1784 	return true;
1785 }
1786 #endif /* CONFIG_KVM */
1787 
1788 /* Internal helper functions to match cpu capability type */
1789 static bool
1790 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1791 {
1792 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1793 }
1794 
1795 static bool
1796 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1797 {
1798 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1799 }
1800 
1801 static bool
1802 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1803 {
1804 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1805 }
1806 
1807 static const struct arm64_cpu_capabilities arm64_features[] = {
1808 	{
1809 		.desc = "GIC system register CPU interface",
1810 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1811 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1812 		.matches = has_useable_gicv3_cpuif,
1813 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1814 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1815 		.sign = FTR_UNSIGNED,
1816 		.min_field_value = 1,
1817 	},
1818 #ifdef CONFIG_ARM64_PAN
1819 	{
1820 		.desc = "Privileged Access Never",
1821 		.capability = ARM64_HAS_PAN,
1822 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1823 		.matches = has_cpuid_feature,
1824 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1825 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1826 		.sign = FTR_UNSIGNED,
1827 		.min_field_value = 1,
1828 		.cpu_enable = cpu_enable_pan,
1829 	},
1830 #endif /* CONFIG_ARM64_PAN */
1831 #ifdef CONFIG_ARM64_EPAN
1832 	{
1833 		.desc = "Enhanced Privileged Access Never",
1834 		.capability = ARM64_HAS_EPAN,
1835 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1836 		.matches = has_cpuid_feature,
1837 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1838 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1839 		.sign = FTR_UNSIGNED,
1840 		.min_field_value = 3,
1841 	},
1842 #endif /* CONFIG_ARM64_EPAN */
1843 #ifdef CONFIG_ARM64_LSE_ATOMICS
1844 	{
1845 		.desc = "LSE atomic instructions",
1846 		.capability = ARM64_HAS_LSE_ATOMICS,
1847 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1848 		.matches = has_cpuid_feature,
1849 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1850 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1851 		.sign = FTR_UNSIGNED,
1852 		.min_field_value = 2,
1853 	},
1854 #endif /* CONFIG_ARM64_LSE_ATOMICS */
1855 	{
1856 		.desc = "Software prefetching using PRFM",
1857 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1858 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1859 		.matches = has_no_hw_prefetch,
1860 	},
1861 	{
1862 		.desc = "Virtualization Host Extensions",
1863 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1864 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1865 		.matches = runs_at_el2,
1866 		.cpu_enable = cpu_copy_el2regs,
1867 	},
1868 	{
1869 		.desc = "32-bit EL0 Support",
1870 		.capability = ARM64_HAS_32BIT_EL0,
1871 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1872 		.matches = has_cpuid_feature,
1873 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1874 		.sign = FTR_UNSIGNED,
1875 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1876 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1877 	},
1878 #ifdef CONFIG_KVM
1879 	{
1880 		.desc = "32-bit EL1 Support",
1881 		.capability = ARM64_HAS_32BIT_EL1,
1882 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1883 		.matches = has_cpuid_feature,
1884 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1885 		.sign = FTR_UNSIGNED,
1886 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
1887 		.min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
1888 	},
1889 	{
1890 		.desc = "Protected KVM",
1891 		.capability = ARM64_KVM_PROTECTED_MODE,
1892 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1893 		.matches = is_kvm_protected_mode,
1894 	},
1895 #endif
1896 	{
1897 		.desc = "Kernel page table isolation (KPTI)",
1898 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1899 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1900 		/*
1901 		 * The ID feature fields below are used to indicate that
1902 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1903 		 * more details.
1904 		 */
1905 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1906 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1907 		.min_field_value = 1,
1908 		.matches = unmap_kernel_at_el0,
1909 		.cpu_enable = kpti_install_ng_mappings,
1910 	},
1911 	{
1912 		/* FP/SIMD is not implemented */
1913 		.capability = ARM64_HAS_NO_FPSIMD,
1914 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1915 		.min_field_value = 0,
1916 		.matches = has_no_fpsimd,
1917 	},
1918 #ifdef CONFIG_ARM64_PMEM
1919 	{
1920 		.desc = "Data cache clean to Point of Persistence",
1921 		.capability = ARM64_HAS_DCPOP,
1922 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1923 		.matches = has_cpuid_feature,
1924 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1925 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1926 		.min_field_value = 1,
1927 	},
1928 	{
1929 		.desc = "Data cache clean to Point of Deep Persistence",
1930 		.capability = ARM64_HAS_DCPODP,
1931 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1932 		.matches = has_cpuid_feature,
1933 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1934 		.sign = FTR_UNSIGNED,
1935 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1936 		.min_field_value = 2,
1937 	},
1938 #endif
1939 #ifdef CONFIG_ARM64_SVE
1940 	{
1941 		.desc = "Scalable Vector Extension",
1942 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1943 		.capability = ARM64_SVE,
1944 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1945 		.sign = FTR_UNSIGNED,
1946 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1947 		.min_field_value = ID_AA64PFR0_SVE,
1948 		.matches = has_cpuid_feature,
1949 		.cpu_enable = sve_kernel_enable,
1950 	},
1951 #endif /* CONFIG_ARM64_SVE */
1952 #ifdef CONFIG_ARM64_RAS_EXTN
1953 	{
1954 		.desc = "RAS Extension Support",
1955 		.capability = ARM64_HAS_RAS_EXTN,
1956 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1957 		.matches = has_cpuid_feature,
1958 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1959 		.sign = FTR_UNSIGNED,
1960 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1961 		.min_field_value = ID_AA64PFR0_RAS_V1,
1962 		.cpu_enable = cpu_clear_disr,
1963 	},
1964 #endif /* CONFIG_ARM64_RAS_EXTN */
1965 #ifdef CONFIG_ARM64_AMU_EXTN
1966 	{
1967 		/*
1968 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
1969 		 * Therefore, don't provide .desc as we don't want the detection
1970 		 * message to be shown until at least one CPU is detected to
1971 		 * support the feature.
1972 		 */
1973 		.capability = ARM64_HAS_AMU_EXTN,
1974 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1975 		.matches = has_amu,
1976 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1977 		.sign = FTR_UNSIGNED,
1978 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
1979 		.min_field_value = ID_AA64PFR0_AMU,
1980 		.cpu_enable = cpu_amu_enable,
1981 	},
1982 #endif /* CONFIG_ARM64_AMU_EXTN */
1983 	{
1984 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1985 		.capability = ARM64_HAS_CACHE_IDC,
1986 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1987 		.matches = has_cache_idc,
1988 		.cpu_enable = cpu_emulate_effective_ctr,
1989 	},
1990 	{
1991 		.desc = "Instruction cache invalidation not required for I/D coherence",
1992 		.capability = ARM64_HAS_CACHE_DIC,
1993 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1994 		.matches = has_cache_dic,
1995 	},
1996 	{
1997 		.desc = "Stage-2 Force Write-Back",
1998 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1999 		.capability = ARM64_HAS_STAGE2_FWB,
2000 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2001 		.sign = FTR_UNSIGNED,
2002 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
2003 		.min_field_value = 1,
2004 		.matches = has_cpuid_feature,
2005 		.cpu_enable = cpu_has_fwb,
2006 	},
2007 	{
2008 		.desc = "ARMv8.4 Translation Table Level",
2009 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2010 		.capability = ARM64_HAS_ARMv8_4_TTL,
2011 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2012 		.sign = FTR_UNSIGNED,
2013 		.field_pos = ID_AA64MMFR2_TTL_SHIFT,
2014 		.min_field_value = 1,
2015 		.matches = has_cpuid_feature,
2016 	},
2017 	{
2018 		.desc = "TLB range maintenance instructions",
2019 		.capability = ARM64_HAS_TLB_RANGE,
2020 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2021 		.matches = has_cpuid_feature,
2022 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2023 		.field_pos = ID_AA64ISAR0_TLB_SHIFT,
2024 		.sign = FTR_UNSIGNED,
2025 		.min_field_value = ID_AA64ISAR0_TLB_RANGE,
2026 	},
2027 #ifdef CONFIG_ARM64_HW_AFDBM
2028 	{
2029 		/*
2030 		 * Since we turn this on always, we don't want the user to
2031 		 * think that the feature is available when it may not be.
2032 		 * So hide the description.
2033 		 *
2034 		 * .desc = "Hardware pagetable Dirty Bit Management",
2035 		 *
2036 		 */
2037 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2038 		.capability = ARM64_HW_DBM,
2039 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
2040 		.sign = FTR_UNSIGNED,
2041 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
2042 		.min_field_value = 2,
2043 		.matches = has_hw_dbm,
2044 		.cpu_enable = cpu_enable_hw_dbm,
2045 	},
2046 #endif
2047 	{
2048 		.desc = "CRC32 instructions",
2049 		.capability = ARM64_HAS_CRC32,
2050 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2051 		.matches = has_cpuid_feature,
2052 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2053 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
2054 		.min_field_value = 1,
2055 	},
2056 	{
2057 		.desc = "Speculative Store Bypassing Safe (SSBS)",
2058 		.capability = ARM64_SSBS,
2059 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2060 		.matches = has_cpuid_feature,
2061 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2062 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
2063 		.sign = FTR_UNSIGNED,
2064 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
2065 	},
2066 #ifdef CONFIG_ARM64_CNP
2067 	{
2068 		.desc = "Common not Private translations",
2069 		.capability = ARM64_HAS_CNP,
2070 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2071 		.matches = has_useable_cnp,
2072 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2073 		.sign = FTR_UNSIGNED,
2074 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
2075 		.min_field_value = 1,
2076 		.cpu_enable = cpu_enable_cnp,
2077 	},
2078 #endif
2079 	{
2080 		.desc = "Speculation barrier (SB)",
2081 		.capability = ARM64_HAS_SB,
2082 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2083 		.matches = has_cpuid_feature,
2084 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2085 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
2086 		.sign = FTR_UNSIGNED,
2087 		.min_field_value = 1,
2088 	},
2089 #ifdef CONFIG_ARM64_PTR_AUTH
2090 	{
2091 		.desc = "Address authentication (architected algorithm)",
2092 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
2093 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2094 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2095 		.sign = FTR_UNSIGNED,
2096 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
2097 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
2098 		.matches = has_address_auth_cpucap,
2099 	},
2100 	{
2101 		.desc = "Address authentication (IMP DEF algorithm)",
2102 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2103 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2104 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2105 		.sign = FTR_UNSIGNED,
2106 		.field_pos = ID_AA64ISAR1_API_SHIFT,
2107 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
2108 		.matches = has_address_auth_cpucap,
2109 	},
2110 	{
2111 		.capability = ARM64_HAS_ADDRESS_AUTH,
2112 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2113 		.matches = has_address_auth_metacap,
2114 	},
2115 	{
2116 		.desc = "Generic authentication (architected algorithm)",
2117 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
2118 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2119 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2120 		.sign = FTR_UNSIGNED,
2121 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
2122 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
2123 		.matches = has_cpuid_feature,
2124 	},
2125 	{
2126 		.desc = "Generic authentication (IMP DEF algorithm)",
2127 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2128 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2129 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2130 		.sign = FTR_UNSIGNED,
2131 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
2132 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
2133 		.matches = has_cpuid_feature,
2134 	},
2135 	{
2136 		.capability = ARM64_HAS_GENERIC_AUTH,
2137 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2138 		.matches = has_generic_auth,
2139 	},
2140 #endif /* CONFIG_ARM64_PTR_AUTH */
2141 #ifdef CONFIG_ARM64_PSEUDO_NMI
2142 	{
2143 		/*
2144 		 * Depends on having GICv3
2145 		 */
2146 		.desc = "IRQ priority masking",
2147 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2148 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2149 		.matches = can_use_gic_priorities,
2150 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2151 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2152 		.sign = FTR_UNSIGNED,
2153 		.min_field_value = 1,
2154 	},
2155 #endif
2156 #ifdef CONFIG_ARM64_E0PD
2157 	{
2158 		.desc = "E0PD",
2159 		.capability = ARM64_HAS_E0PD,
2160 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2161 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2162 		.sign = FTR_UNSIGNED,
2163 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2164 		.matches = has_cpuid_feature,
2165 		.min_field_value = 1,
2166 		.cpu_enable = cpu_enable_e0pd,
2167 	},
2168 #endif
2169 #ifdef CONFIG_ARCH_RANDOM
2170 	{
2171 		.desc = "Random Number Generator",
2172 		.capability = ARM64_HAS_RNG,
2173 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2174 		.matches = has_cpuid_feature,
2175 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2176 		.field_pos = ID_AA64ISAR0_RNDR_SHIFT,
2177 		.sign = FTR_UNSIGNED,
2178 		.min_field_value = 1,
2179 	},
2180 #endif
2181 #ifdef CONFIG_ARM64_BTI
2182 	{
2183 		.desc = "Branch Target Identification",
2184 		.capability = ARM64_BTI,
2185 #ifdef CONFIG_ARM64_BTI_KERNEL
2186 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2187 #else
2188 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2189 #endif
2190 		.matches = has_cpuid_feature,
2191 		.cpu_enable = bti_enable,
2192 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2193 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2194 		.min_field_value = ID_AA64PFR1_BT_BTI,
2195 		.sign = FTR_UNSIGNED,
2196 	},
2197 #endif
2198 #ifdef CONFIG_ARM64_MTE
2199 	{
2200 		.desc = "Memory Tagging Extension",
2201 		.capability = ARM64_MTE,
2202 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2203 		.matches = has_cpuid_feature,
2204 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2205 		.field_pos = ID_AA64PFR1_MTE_SHIFT,
2206 		.min_field_value = ID_AA64PFR1_MTE,
2207 		.sign = FTR_UNSIGNED,
2208 		.cpu_enable = cpu_enable_mte,
2209 	},
2210 #endif /* CONFIG_ARM64_MTE */
2211 	{
2212 		.desc = "RCpc load-acquire (LDAPR)",
2213 		.capability = ARM64_HAS_LDAPR,
2214 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2215 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2216 		.sign = FTR_UNSIGNED,
2217 		.field_pos = ID_AA64ISAR1_LRCPC_SHIFT,
2218 		.matches = has_cpuid_feature,
2219 		.min_field_value = 1,
2220 	},
2221 	{},
2222 };
2223 
2224 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
2225 		.matches = has_cpuid_feature,					\
2226 		.sys_reg = reg,							\
2227 		.field_pos = field,						\
2228 		.sign = s,							\
2229 		.min_field_value = min_value,
2230 
2231 #define __HWCAP_CAP(name, cap_type, cap)					\
2232 		.desc = name,							\
2233 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2234 		.hwcap_type = cap_type,						\
2235 		.hwcap = cap,							\
2236 
2237 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
2238 	{									\
2239 		__HWCAP_CAP(#cap, cap_type, cap)				\
2240 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
2241 	}
2242 
2243 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2244 	{									\
2245 		__HWCAP_CAP(#cap, cap_type, cap)				\
2246 		.matches = cpucap_multi_entry_cap_matches,			\
2247 		.match_list = list,						\
2248 	}
2249 
2250 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2251 	{									\
2252 		__HWCAP_CAP(#cap, cap_type, cap)				\
2253 		.matches = match,						\
2254 	}
2255 
2256 #ifdef CONFIG_ARM64_PTR_AUTH
2257 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2258 	{
2259 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2260 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
2261 	},
2262 	{
2263 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2264 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2265 	},
2266 	{},
2267 };
2268 
2269 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2270 	{
2271 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2272 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2273 	},
2274 	{
2275 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2276 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2277 	},
2278 	{},
2279 };
2280 #endif
2281 
2282 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2283 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2284 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2285 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2286 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2287 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2288 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2289 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2290 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2291 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2292 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2293 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2294 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2295 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2296 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2297 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2298 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2299 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2300 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2301 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2302 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2303 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2304 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2305 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2306 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2307 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2308 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2309 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2310 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2311 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2312 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2313 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2314 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2315 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2316 #ifdef CONFIG_ARM64_SVE
2317 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2318 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2319 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2320 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2321 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2322 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2323 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2324 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2325 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2326 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2327 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2328 #endif
2329 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2330 #ifdef CONFIG_ARM64_BTI
2331 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2332 #endif
2333 #ifdef CONFIG_ARM64_PTR_AUTH
2334 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2335 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2336 #endif
2337 #ifdef CONFIG_ARM64_MTE
2338 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE),
2339 #endif /* CONFIG_ARM64_MTE */
2340 	{},
2341 };
2342 
2343 #ifdef CONFIG_COMPAT
2344 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2345 {
2346 	/*
2347 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2348 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2349 	 * check is future proof, by making sure value is non-zero.
2350 	 */
2351 	u32 mvfr1;
2352 
2353 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2354 	if (scope == SCOPE_SYSTEM)
2355 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2356 	else
2357 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2358 
2359 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2360 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2361 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2362 }
2363 #endif
2364 
2365 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2366 #ifdef CONFIG_COMPAT
2367 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2368 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2369 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2370 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2371 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2372 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2373 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2374 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2375 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2376 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2377 #endif
2378 	{},
2379 };
2380 
2381 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2382 {
2383 	switch (cap->hwcap_type) {
2384 	case CAP_HWCAP:
2385 		cpu_set_feature(cap->hwcap);
2386 		break;
2387 #ifdef CONFIG_COMPAT
2388 	case CAP_COMPAT_HWCAP:
2389 		compat_elf_hwcap |= (u32)cap->hwcap;
2390 		break;
2391 	case CAP_COMPAT_HWCAP2:
2392 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2393 		break;
2394 #endif
2395 	default:
2396 		WARN_ON(1);
2397 		break;
2398 	}
2399 }
2400 
2401 /* Check if we have a particular HWCAP enabled */
2402 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2403 {
2404 	bool rc;
2405 
2406 	switch (cap->hwcap_type) {
2407 	case CAP_HWCAP:
2408 		rc = cpu_have_feature(cap->hwcap);
2409 		break;
2410 #ifdef CONFIG_COMPAT
2411 	case CAP_COMPAT_HWCAP:
2412 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2413 		break;
2414 	case CAP_COMPAT_HWCAP2:
2415 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2416 		break;
2417 #endif
2418 	default:
2419 		WARN_ON(1);
2420 		rc = false;
2421 	}
2422 
2423 	return rc;
2424 }
2425 
2426 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2427 {
2428 	/* We support emulation of accesses to CPU ID feature registers */
2429 	cpu_set_named_feature(CPUID);
2430 	for (; hwcaps->matches; hwcaps++)
2431 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2432 			cap_set_elf_hwcap(hwcaps);
2433 }
2434 
2435 static void update_cpu_capabilities(u16 scope_mask)
2436 {
2437 	int i;
2438 	const struct arm64_cpu_capabilities *caps;
2439 
2440 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2441 	for (i = 0; i < ARM64_NCAPS; i++) {
2442 		caps = cpu_hwcaps_ptrs[i];
2443 		if (!caps || !(caps->type & scope_mask) ||
2444 		    cpus_have_cap(caps->capability) ||
2445 		    !caps->matches(caps, cpucap_default_scope(caps)))
2446 			continue;
2447 
2448 		if (caps->desc)
2449 			pr_info("detected: %s\n", caps->desc);
2450 		cpus_set_cap(caps->capability);
2451 
2452 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2453 			set_bit(caps->capability, boot_capabilities);
2454 	}
2455 }
2456 
2457 /*
2458  * Enable all the available capabilities on this CPU. The capabilities
2459  * with BOOT_CPU scope are handled separately and hence skipped here.
2460  */
2461 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2462 {
2463 	int i;
2464 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2465 
2466 	for_each_available_cap(i) {
2467 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2468 
2469 		if (WARN_ON(!cap))
2470 			continue;
2471 
2472 		if (!(cap->type & non_boot_scope))
2473 			continue;
2474 
2475 		if (cap->cpu_enable)
2476 			cap->cpu_enable(cap);
2477 	}
2478 	return 0;
2479 }
2480 
2481 /*
2482  * Run through the enabled capabilities and enable() it on all active
2483  * CPUs
2484  */
2485 static void __init enable_cpu_capabilities(u16 scope_mask)
2486 {
2487 	int i;
2488 	const struct arm64_cpu_capabilities *caps;
2489 	bool boot_scope;
2490 
2491 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2492 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2493 
2494 	for (i = 0; i < ARM64_NCAPS; i++) {
2495 		unsigned int num;
2496 
2497 		caps = cpu_hwcaps_ptrs[i];
2498 		if (!caps || !(caps->type & scope_mask))
2499 			continue;
2500 		num = caps->capability;
2501 		if (!cpus_have_cap(num))
2502 			continue;
2503 
2504 		/* Ensure cpus_have_const_cap(num) works */
2505 		static_branch_enable(&cpu_hwcap_keys[num]);
2506 
2507 		if (boot_scope && caps->cpu_enable)
2508 			/*
2509 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2510 			 * before any secondary CPU boots. Thus, each secondary
2511 			 * will enable the capability as appropriate via
2512 			 * check_local_cpu_capabilities(). The only exception is
2513 			 * the boot CPU, for which the capability must be
2514 			 * enabled here. This approach avoids costly
2515 			 * stop_machine() calls for this case.
2516 			 */
2517 			caps->cpu_enable(caps);
2518 	}
2519 
2520 	/*
2521 	 * For all non-boot scope capabilities, use stop_machine()
2522 	 * as it schedules the work allowing us to modify PSTATE,
2523 	 * instead of on_each_cpu() which uses an IPI, giving us a
2524 	 * PSTATE that disappears when we return.
2525 	 */
2526 	if (!boot_scope)
2527 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2528 			     NULL, cpu_online_mask);
2529 }
2530 
2531 /*
2532  * Run through the list of capabilities to check for conflicts.
2533  * If the system has already detected a capability, take necessary
2534  * action on this CPU.
2535  */
2536 static void verify_local_cpu_caps(u16 scope_mask)
2537 {
2538 	int i;
2539 	bool cpu_has_cap, system_has_cap;
2540 	const struct arm64_cpu_capabilities *caps;
2541 
2542 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2543 
2544 	for (i = 0; i < ARM64_NCAPS; i++) {
2545 		caps = cpu_hwcaps_ptrs[i];
2546 		if (!caps || !(caps->type & scope_mask))
2547 			continue;
2548 
2549 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2550 		system_has_cap = cpus_have_cap(caps->capability);
2551 
2552 		if (system_has_cap) {
2553 			/*
2554 			 * Check if the new CPU misses an advertised feature,
2555 			 * which is not safe to miss.
2556 			 */
2557 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2558 				break;
2559 			/*
2560 			 * We have to issue cpu_enable() irrespective of
2561 			 * whether the CPU has it or not, as it is enabeld
2562 			 * system wide. It is upto the call back to take
2563 			 * appropriate action on this CPU.
2564 			 */
2565 			if (caps->cpu_enable)
2566 				caps->cpu_enable(caps);
2567 		} else {
2568 			/*
2569 			 * Check if the CPU has this capability if it isn't
2570 			 * safe to have when the system doesn't.
2571 			 */
2572 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2573 				break;
2574 		}
2575 	}
2576 
2577 	if (i < ARM64_NCAPS) {
2578 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2579 			smp_processor_id(), caps->capability,
2580 			caps->desc, system_has_cap, cpu_has_cap);
2581 
2582 		if (cpucap_panic_on_conflict(caps))
2583 			cpu_panic_kernel();
2584 		else
2585 			cpu_die_early();
2586 	}
2587 }
2588 
2589 /*
2590  * Check for CPU features that are used in early boot
2591  * based on the Boot CPU value.
2592  */
2593 static void check_early_cpu_features(void)
2594 {
2595 	verify_cpu_asid_bits();
2596 
2597 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2598 }
2599 
2600 static void
2601 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2602 {
2603 
2604 	for (; caps->matches; caps++)
2605 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2606 			pr_crit("CPU%d: missing HWCAP: %s\n",
2607 					smp_processor_id(), caps->desc);
2608 			cpu_die_early();
2609 		}
2610 }
2611 
2612 static void verify_sve_features(void)
2613 {
2614 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2615 	u64 zcr = read_zcr_features();
2616 
2617 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2618 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2619 
2620 	if (len < safe_len || sve_verify_vq_map()) {
2621 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2622 			smp_processor_id());
2623 		cpu_die_early();
2624 	}
2625 
2626 	/* Add checks on other ZCR bits here if necessary */
2627 }
2628 
2629 static void verify_hyp_capabilities(void)
2630 {
2631 	u64 safe_mmfr1, mmfr0, mmfr1;
2632 	int parange, ipa_max;
2633 	unsigned int safe_vmid_bits, vmid_bits;
2634 
2635 	if (!IS_ENABLED(CONFIG_KVM))
2636 		return;
2637 
2638 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2639 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2640 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2641 
2642 	/* Verify VMID bits */
2643 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2644 	vmid_bits = get_vmid_bits(mmfr1);
2645 	if (vmid_bits < safe_vmid_bits) {
2646 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
2647 		cpu_die_early();
2648 	}
2649 
2650 	/* Verify IPA range */
2651 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
2652 				ID_AA64MMFR0_PARANGE_SHIFT);
2653 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
2654 	if (ipa_max < get_kvm_ipa_limit()) {
2655 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
2656 		cpu_die_early();
2657 	}
2658 }
2659 
2660 /*
2661  * Run through the enabled system capabilities and enable() it on this CPU.
2662  * The capabilities were decided based on the available CPUs at the boot time.
2663  * Any new CPU should match the system wide status of the capability. If the
2664  * new CPU doesn't have a capability which the system now has enabled, we
2665  * cannot do anything to fix it up and could cause unexpected failures. So
2666  * we park the CPU.
2667  */
2668 static void verify_local_cpu_capabilities(void)
2669 {
2670 	/*
2671 	 * The capabilities with SCOPE_BOOT_CPU are checked from
2672 	 * check_early_cpu_features(), as they need to be verified
2673 	 * on all secondary CPUs.
2674 	 */
2675 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2676 
2677 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
2678 
2679 	if (system_supports_32bit_el0())
2680 		verify_local_elf_hwcaps(compat_elf_hwcaps);
2681 
2682 	if (system_supports_sve())
2683 		verify_sve_features();
2684 
2685 	if (is_hyp_mode_available())
2686 		verify_hyp_capabilities();
2687 }
2688 
2689 void check_local_cpu_capabilities(void)
2690 {
2691 	/*
2692 	 * All secondary CPUs should conform to the early CPU features
2693 	 * in use by the kernel based on boot CPU.
2694 	 */
2695 	check_early_cpu_features();
2696 
2697 	/*
2698 	 * If we haven't finalised the system capabilities, this CPU gets
2699 	 * a chance to update the errata work arounds and local features.
2700 	 * Otherwise, this CPU should verify that it has all the system
2701 	 * advertised capabilities.
2702 	 */
2703 	if (!system_capabilities_finalized())
2704 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
2705 	else
2706 		verify_local_cpu_capabilities();
2707 }
2708 
2709 static void __init setup_boot_cpu_capabilities(void)
2710 {
2711 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
2712 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
2713 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
2714 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
2715 }
2716 
2717 bool this_cpu_has_cap(unsigned int n)
2718 {
2719 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
2720 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2721 
2722 		if (cap)
2723 			return cap->matches(cap, SCOPE_LOCAL_CPU);
2724 	}
2725 
2726 	return false;
2727 }
2728 
2729 /*
2730  * This helper function is used in a narrow window when,
2731  * - The system wide safe registers are set with all the SMP CPUs and,
2732  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
2733  * In all other cases cpus_have_{const_}cap() should be used.
2734  */
2735 static bool __maybe_unused __system_matches_cap(unsigned int n)
2736 {
2737 	if (n < ARM64_NCAPS) {
2738 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2739 
2740 		if (cap)
2741 			return cap->matches(cap, SCOPE_SYSTEM);
2742 	}
2743 	return false;
2744 }
2745 
2746 void cpu_set_feature(unsigned int num)
2747 {
2748 	WARN_ON(num >= MAX_CPU_FEATURES);
2749 	elf_hwcap |= BIT(num);
2750 }
2751 EXPORT_SYMBOL_GPL(cpu_set_feature);
2752 
2753 bool cpu_have_feature(unsigned int num)
2754 {
2755 	WARN_ON(num >= MAX_CPU_FEATURES);
2756 	return elf_hwcap & BIT(num);
2757 }
2758 EXPORT_SYMBOL_GPL(cpu_have_feature);
2759 
2760 unsigned long cpu_get_elf_hwcap(void)
2761 {
2762 	/*
2763 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2764 	 * note that for userspace compatibility we guarantee that bits 62
2765 	 * and 63 will always be returned as 0.
2766 	 */
2767 	return lower_32_bits(elf_hwcap);
2768 }
2769 
2770 unsigned long cpu_get_elf_hwcap2(void)
2771 {
2772 	return upper_32_bits(elf_hwcap);
2773 }
2774 
2775 static void __init setup_system_capabilities(void)
2776 {
2777 	/*
2778 	 * We have finalised the system-wide safe feature
2779 	 * registers, finalise the capabilities that depend
2780 	 * on it. Also enable all the available capabilities,
2781 	 * that are not enabled already.
2782 	 */
2783 	update_cpu_capabilities(SCOPE_SYSTEM);
2784 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2785 }
2786 
2787 void __init setup_cpu_features(void)
2788 {
2789 	u32 cwg;
2790 
2791 	setup_system_capabilities();
2792 	setup_elf_hwcaps(arm64_elf_hwcaps);
2793 
2794 	if (system_supports_32bit_el0())
2795 		setup_elf_hwcaps(compat_elf_hwcaps);
2796 
2797 	if (system_uses_ttbr0_pan())
2798 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2799 
2800 	sve_setup();
2801 	minsigstksz_setup();
2802 
2803 	/* Advertise that we have computed the system capabilities */
2804 	finalize_system_capabilities();
2805 
2806 	/*
2807 	 * Check for sane CTR_EL0.CWG value.
2808 	 */
2809 	cwg = cache_type_cwg();
2810 	if (!cwg)
2811 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2812 			ARCH_DMA_MINALIGN);
2813 }
2814 
2815 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2816 {
2817 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2818 }
2819 
2820 /*
2821  * We emulate only the following system register space.
2822  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2823  * See Table C5-6 System instruction encodings for System register accesses,
2824  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2825  */
2826 static inline bool __attribute_const__ is_emulated(u32 id)
2827 {
2828 	return (sys_reg_Op0(id) == 0x3 &&
2829 		sys_reg_CRn(id) == 0x0 &&
2830 		sys_reg_Op1(id) == 0x0 &&
2831 		(sys_reg_CRm(id) == 0 ||
2832 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2833 }
2834 
2835 /*
2836  * With CRm == 0, reg should be one of :
2837  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2838  */
2839 static inline int emulate_id_reg(u32 id, u64 *valp)
2840 {
2841 	switch (id) {
2842 	case SYS_MIDR_EL1:
2843 		*valp = read_cpuid_id();
2844 		break;
2845 	case SYS_MPIDR_EL1:
2846 		*valp = SYS_MPIDR_SAFE_VAL;
2847 		break;
2848 	case SYS_REVIDR_EL1:
2849 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2850 		*valp = 0;
2851 		break;
2852 	default:
2853 		return -EINVAL;
2854 	}
2855 
2856 	return 0;
2857 }
2858 
2859 static int emulate_sys_reg(u32 id, u64 *valp)
2860 {
2861 	struct arm64_ftr_reg *regp;
2862 
2863 	if (!is_emulated(id))
2864 		return -EINVAL;
2865 
2866 	if (sys_reg_CRm(id) == 0)
2867 		return emulate_id_reg(id, valp);
2868 
2869 	regp = get_arm64_ftr_reg_nowarn(id);
2870 	if (regp)
2871 		*valp = arm64_ftr_reg_user_value(regp);
2872 	else
2873 		/*
2874 		 * The untracked registers are either IMPLEMENTATION DEFINED
2875 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2876 		 */
2877 		*valp = 0;
2878 	return 0;
2879 }
2880 
2881 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2882 {
2883 	int rc;
2884 	u64 val;
2885 
2886 	rc = emulate_sys_reg(sys_reg, &val);
2887 	if (!rc) {
2888 		pt_regs_write_reg(regs, rt, val);
2889 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2890 	}
2891 	return rc;
2892 }
2893 
2894 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2895 {
2896 	u32 sys_reg, rt;
2897 
2898 	/*
2899 	 * sys_reg values are defined as used in mrs/msr instruction.
2900 	 * shift the imm value to get the encoding.
2901 	 */
2902 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2903 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2904 	return do_emulate_mrs(regs, sys_reg, rt);
2905 }
2906 
2907 static struct undef_hook mrs_hook = {
2908 	.instr_mask = 0xfff00000,
2909 	.instr_val  = 0xd5300000,
2910 	.pstate_mask = PSR_AA32_MODE_MASK,
2911 	.pstate_val = PSR_MODE_EL0t,
2912 	.fn = emulate_mrs,
2913 };
2914 
2915 static int __init enable_mrs_emulation(void)
2916 {
2917 	register_undef_hook(&mrs_hook);
2918 	return 0;
2919 }
2920 
2921 core_initcall(enable_mrs_emulation);
2922 
2923 enum mitigation_state arm64_get_meltdown_state(void)
2924 {
2925 	if (__meltdown_safe)
2926 		return SPECTRE_UNAFFECTED;
2927 
2928 	if (arm64_kernel_unmapped_at_el0())
2929 		return SPECTRE_MITIGATED;
2930 
2931 	return SPECTRE_VULNERABLE;
2932 }
2933 
2934 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2935 			  char *buf)
2936 {
2937 	switch (arm64_get_meltdown_state()) {
2938 	case SPECTRE_UNAFFECTED:
2939 		return sprintf(buf, "Not affected\n");
2940 
2941 	case SPECTRE_MITIGATED:
2942 		return sprintf(buf, "Mitigation: PTI\n");
2943 
2944 	default:
2945 		return sprintf(buf, "Vulnerable\n");
2946 	}
2947 }
2948