xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision 3aa139aa9fdc138a84243dc49dc18d9b40e1c6e4)
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/mm.h>
72 #include <linux/cpu.h>
73 #include <linux/kasan.h>
74 #include <asm/cpu.h>
75 #include <asm/cpufeature.h>
76 #include <asm/cpu_ops.h>
77 #include <asm/fpsimd.h>
78 #include <asm/kvm_host.h>
79 #include <asm/mmu_context.h>
80 #include <asm/mte.h>
81 #include <asm/processor.h>
82 #include <asm/sysreg.h>
83 #include <asm/traps.h>
84 #include <asm/virt.h>
85 
86 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
87 static unsigned long elf_hwcap __read_mostly;
88 
89 #ifdef CONFIG_COMPAT
90 #define COMPAT_ELF_HWCAP_DEFAULT	\
91 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
92 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
93 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\
94 				 COMPAT_HWCAP_LPAE)
95 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
96 unsigned int compat_elf_hwcap2 __read_mostly;
97 #endif
98 
99 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
100 EXPORT_SYMBOL(cpu_hwcaps);
101 static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
102 
103 /* Need also bit for ARM64_CB_PATCH */
104 DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
105 
106 bool arm64_use_ng_mappings = false;
107 EXPORT_SYMBOL(arm64_use_ng_mappings);
108 
109 /*
110  * Flag to indicate if we have computed the system wide
111  * capabilities based on the boot time active CPUs. This
112  * will be used to determine if a new booting CPU should
113  * go through the verification process to make sure that it
114  * supports the system capabilities, without using a hotplug
115  * notifier. This is also used to decide if we could use
116  * the fast path for checking constant CPU caps.
117  */
118 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
119 EXPORT_SYMBOL(arm64_const_caps_ready);
120 static inline void finalize_system_capabilities(void)
121 {
122 	static_branch_enable(&arm64_const_caps_ready);
123 }
124 
125 void dump_cpu_features(void)
126 {
127 	/* file-wide pr_fmt adds "CPU features: " prefix */
128 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
129 }
130 
131 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
132 EXPORT_SYMBOL(cpu_hwcap_keys);
133 
134 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
135 	{						\
136 		.sign = SIGNED,				\
137 		.visible = VISIBLE,			\
138 		.strict = STRICT,			\
139 		.type = TYPE,				\
140 		.shift = SHIFT,				\
141 		.width = WIDTH,				\
142 		.safe_val = SAFE_VAL,			\
143 	}
144 
145 /* Define a feature with unsigned values */
146 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
147 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
148 
149 /* Define a feature with a signed value */
150 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
151 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
152 
153 #define ARM64_FTR_END					\
154 	{						\
155 		.width = 0,				\
156 	}
157 
158 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
159 
160 static bool __system_matches_cap(unsigned int n);
161 
162 /*
163  * NOTE: Any changes to the visibility of features should be kept in
164  * sync with the documentation of the CPU feature register ABI.
165  */
166 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
167 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0),
168 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TLB_SHIFT, 4, 0),
169 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
170 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
171 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
172 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
173 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
174 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
175 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
176 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
177 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
178 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
179 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
180 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
181 	ARM64_FTR_END,
182 };
183 
184 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
185 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
186 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DGH_SHIFT, 4, 0),
187 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_BF16_SHIFT, 4, 0),
188 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SPECRES_SHIFT, 4, 0),
189 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
192 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
193 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
194 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
195 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
196 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
197 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
198 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
199 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_API_SHIFT, 4, 0),
200 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
201 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_APA_SHIFT, 4, 0),
202 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
203 	ARM64_FTR_END,
204 };
205 
206 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
207 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
208 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
209 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
210 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_AMU_SHIFT, 4, 0),
211 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_MPAM_SHIFT, 4, 0),
212 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SEL2_SHIFT, 4, 0),
213 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
214 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
215 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
217 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
218 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
219 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
220 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
221 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
222 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
223 	ARM64_FTR_END,
224 };
225 
226 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
227 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
228 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
230 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MTE_SHIFT, 4, ID_AA64PFR1_MTE_NI),
231 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
232 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
233 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
234 	ARM64_FTR_END,
235 };
236 
237 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
238 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
239 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
240 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
241 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
242 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
243 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
244 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
245 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
246 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
247 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
248 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
249 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BF16_SHIFT, 4, 0),
250 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
251 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
252 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
253 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
254 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
255 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
256 	ARM64_FTR_END,
257 };
258 
259 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
260 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0),
261 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0),
262 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EXS_SHIFT, 4, 0),
263 	/*
264 	 * Page size not being supported at Stage-2 is not fatal. You
265 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
266 	 * your favourite nesting hypervisor.
267 	 *
268 	 * There is a small corner case where the hypervisor explicitly
269 	 * advertises a given granule size at Stage-2 (value 2) on some
270 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
271 	 * vCPUs. Although this is not forbidden by the architecture, it
272 	 * indicates that the hypervisor is being silly (or buggy).
273 	 *
274 	 * We make no effort to cope with this and pretend that if these
275 	 * fields are inconsistent across vCPUs, then it isn't worth
276 	 * trying to bring KVM up.
277 	 */
278 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
279 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
280 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
281 	/*
282 	 * We already refuse to boot CPUs that don't support our configured
283 	 * page size, so we can only detect mismatches for a page size other
284 	 * than the one we're currently using. Unfortunately, SoCs like this
285 	 * exist in the wild so, even though we don't like it, we'll have to go
286 	 * along with it and treat them as non-strict.
287 	 */
288 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
289 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
290 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
291 
292 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
293 	/* Linux shouldn't care about secure memory */
294 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
295 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
296 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
297 	/*
298 	 * Differing PARange is fine as long as all peripherals and memory are mapped
299 	 * within the minimum PARange of all CPUs
300 	 */
301 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
302 	ARM64_FTR_END,
303 };
304 
305 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
306 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_ETS_SHIFT, 4, 0),
307 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_TWED_SHIFT, 4, 0),
308 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_XNX_SHIFT, 4, 0),
309 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64MMFR1_SPECSEI_SHIFT, 4, 0),
310 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
311 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
312 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
313 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
314 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
315 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
316 	ARM64_FTR_END,
317 };
318 
319 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
320 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0),
321 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EVT_SHIFT, 4, 0),
322 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_BBM_SHIFT, 4, 0),
323 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0),
324 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
325 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IDS_SHIFT, 4, 0),
326 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
327 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_ST_SHIFT, 4, 0),
328 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_NV_SHIFT, 4, 0),
329 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CCIDX_SHIFT, 4, 0),
330 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
331 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
332 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
333 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
334 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
335 	ARM64_FTR_END,
336 };
337 
338 static const struct arm64_ftr_bits ftr_ctr[] = {
339 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
340 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
341 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
342 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
343 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
344 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
345 	/*
346 	 * Linux can handle differing I-cache policies. Userspace JITs will
347 	 * make use of *minLine.
348 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
349 	 */
350 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, CTR_L1IP_SHIFT, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
351 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
352 	ARM64_FTR_END,
353 };
354 
355 static struct arm64_ftr_override __ro_after_init no_override = { };
356 
357 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
358 	.name		= "SYS_CTR_EL0",
359 	.ftr_bits	= ftr_ctr,
360 	.override	= &no_override,
361 };
362 
363 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
364 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_INNERSHR_SHIFT, 4, 0xf),
365 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_FCSE_SHIFT, 4, 0),
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_AUXREG_SHIFT, 4, 0),
367 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_TCM_SHIFT, 4, 0),
368 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_SHARELVL_SHIFT, 4, 0),
369 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_OUTERSHR_SHIFT, 4, 0xf),
370 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_PMSA_SHIFT, 4, 0),
371 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_VMSA_SHIFT, 4, 0),
372 	ARM64_FTR_END,
373 };
374 
375 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
376 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_DOUBLELOCK_SHIFT, 4, 0),
377 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
378 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
379 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
380 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
381 	/*
382 	 * We can instantiate multiple PMU instances with different levels
383 	 * of support.
384 	 */
385 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
386 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
387 	ARM64_FTR_END,
388 };
389 
390 static const struct arm64_ftr_bits ftr_mvfr2[] = {
391 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_FPMISC_SHIFT, 4, 0),
392 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_SIMDMISC_SHIFT, 4, 0),
393 	ARM64_FTR_END,
394 };
395 
396 static const struct arm64_ftr_bits ftr_dczid[] = {
397 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_DZP_SHIFT, 1, 1),
398 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_BS_SHIFT, 4, 0),
399 	ARM64_FTR_END,
400 };
401 
402 static const struct arm64_ftr_bits ftr_id_isar0[] = {
403 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
404 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
405 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
406 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
407 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
408 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
409 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
410 	ARM64_FTR_END,
411 };
412 
413 static const struct arm64_ftr_bits ftr_id_isar5[] = {
414 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
415 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
416 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
417 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
418 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
419 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
420 	ARM64_FTR_END,
421 };
422 
423 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
424 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
427 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
428 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
429 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
430 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_AC2_SHIFT, 4, 0),
431 
432 	/*
433 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
434 	 * external abort on speculative read. It is safe to assume that an
435 	 * SError might be generated than it will not be. Hence it has been
436 	 * classified as FTR_HIGHER_SAFE.
437 	 */
438 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
439 	ARM64_FTR_END,
440 };
441 
442 static const struct arm64_ftr_bits ftr_id_isar4[] = {
443 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
444 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
446 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
447 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
448 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
449 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
450 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
451 	ARM64_FTR_END,
452 };
453 
454 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
455 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
456 	ARM64_FTR_END,
457 };
458 
459 static const struct arm64_ftr_bits ftr_id_isar6[] = {
460 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
463 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
464 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
465 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
466 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
467 	ARM64_FTR_END,
468 };
469 
470 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
471 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
472 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE3_SHIFT, 4, 0),
474 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE2_SHIFT, 4, 0),
475 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE1_SHIFT, 4, 0),
476 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE0_SHIFT, 4, 0),
477 	ARM64_FTR_END,
478 };
479 
480 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
481 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
484 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
485 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
486 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
487 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
488 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
489 	ARM64_FTR_END,
490 };
491 
492 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
493 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
494 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
495 	ARM64_FTR_END,
496 };
497 
498 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
499 	/* [31:28] TraceFilt */
500 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_PERFMON_SHIFT, 4, 0xf),
501 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MPROFDBG_SHIFT, 4, 0),
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPTRC_SHIFT, 4, 0),
503 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPTRC_SHIFT, 4, 0),
504 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPDBG_SHIFT, 4, 0),
505 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPSDBG_SHIFT, 4, 0),
506 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPDBG_SHIFT, 4, 0),
507 	ARM64_FTR_END,
508 };
509 
510 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
511 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
512 	ARM64_FTR_END,
513 };
514 
515 static const struct arm64_ftr_bits ftr_zcr[] = {
516 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
517 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
518 	ARM64_FTR_END,
519 };
520 
521 /*
522  * Common ftr bits for a 32bit register with all hidden, strict
523  * attributes, with 4bit feature fields and a default safe value of
524  * 0. Covers the following 32bit registers:
525  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
526  */
527 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
531 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
532 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
533 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
534 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
535 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
536 	ARM64_FTR_END,
537 };
538 
539 /* Table for a single 32bit feature value */
540 static const struct arm64_ftr_bits ftr_single32[] = {
541 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
542 	ARM64_FTR_END,
543 };
544 
545 static const struct arm64_ftr_bits ftr_raz[] = {
546 	ARM64_FTR_END,
547 };
548 
549 #define ARM64_FTR_REG_OVERRIDE(id, table, ovr) {		\
550 		.sys_id = id,					\
551 		.reg = 	&(struct arm64_ftr_reg){		\
552 			.name = #id,				\
553 			.override = (ovr),			\
554 			.ftr_bits = &((table)[0]),		\
555 	}}
556 
557 #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, &no_override)
558 
559 struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override;
560 struct arm64_ftr_override __ro_after_init id_aa64pfr1_override;
561 struct arm64_ftr_override __ro_after_init id_aa64isar1_override;
562 
563 static const struct __ftr_reg_entry {
564 	u32			sys_id;
565 	struct arm64_ftr_reg 	*reg;
566 } arm64_ftr_regs[] = {
567 
568 	/* Op1 = 0, CRn = 0, CRm = 1 */
569 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
570 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
571 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
572 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
573 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
574 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
575 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
576 
577 	/* Op1 = 0, CRn = 0, CRm = 2 */
578 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
579 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
580 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
581 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
582 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
583 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
584 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
585 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
586 
587 	/* Op1 = 0, CRn = 0, CRm = 3 */
588 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
589 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
590 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
591 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
592 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
593 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
594 
595 	/* Op1 = 0, CRn = 0, CRm = 4 */
596 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
597 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1,
598 			       &id_aa64pfr1_override),
599 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
600 
601 	/* Op1 = 0, CRn = 0, CRm = 5 */
602 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
603 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
604 
605 	/* Op1 = 0, CRn = 0, CRm = 6 */
606 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
607 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1,
608 			       &id_aa64isar1_override),
609 
610 	/* Op1 = 0, CRn = 0, CRm = 7 */
611 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
612 	ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1,
613 			       &id_aa64mmfr1_override),
614 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
615 
616 	/* Op1 = 0, CRn = 1, CRm = 2 */
617 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
618 
619 	/* Op1 = 3, CRn = 0, CRm = 0 */
620 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
621 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
622 
623 	/* Op1 = 3, CRn = 14, CRm = 0 */
624 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
625 };
626 
627 static int search_cmp_ftr_reg(const void *id, const void *regp)
628 {
629 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
630 }
631 
632 /*
633  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
634  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
635  * ascending order of sys_id, we use binary search to find a matching
636  * entry.
637  *
638  * returns - Upon success,  matching ftr_reg entry for id.
639  *         - NULL on failure. It is upto the caller to decide
640  *	     the impact of a failure.
641  */
642 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
643 {
644 	const struct __ftr_reg_entry *ret;
645 
646 	ret = bsearch((const void *)(unsigned long)sys_id,
647 			arm64_ftr_regs,
648 			ARRAY_SIZE(arm64_ftr_regs),
649 			sizeof(arm64_ftr_regs[0]),
650 			search_cmp_ftr_reg);
651 	if (ret)
652 		return ret->reg;
653 	return NULL;
654 }
655 
656 /*
657  * get_arm64_ftr_reg - Looks up a feature register entry using
658  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
659  *
660  * returns - Upon success,  matching ftr_reg entry for id.
661  *         - NULL on failure but with an WARN_ON().
662  */
663 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
664 {
665 	struct arm64_ftr_reg *reg;
666 
667 	reg = get_arm64_ftr_reg_nowarn(sys_id);
668 
669 	/*
670 	 * Requesting a non-existent register search is an error. Warn
671 	 * and let the caller handle it.
672 	 */
673 	WARN_ON(!reg);
674 	return reg;
675 }
676 
677 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
678 			       s64 ftr_val)
679 {
680 	u64 mask = arm64_ftr_mask(ftrp);
681 
682 	reg &= ~mask;
683 	reg |= (ftr_val << ftrp->shift) & mask;
684 	return reg;
685 }
686 
687 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
688 				s64 cur)
689 {
690 	s64 ret = 0;
691 
692 	switch (ftrp->type) {
693 	case FTR_EXACT:
694 		ret = ftrp->safe_val;
695 		break;
696 	case FTR_LOWER_SAFE:
697 		ret = new < cur ? new : cur;
698 		break;
699 	case FTR_HIGHER_OR_ZERO_SAFE:
700 		if (!cur || !new)
701 			break;
702 		fallthrough;
703 	case FTR_HIGHER_SAFE:
704 		ret = new > cur ? new : cur;
705 		break;
706 	default:
707 		BUG();
708 	}
709 
710 	return ret;
711 }
712 
713 static void __init sort_ftr_regs(void)
714 {
715 	unsigned int i;
716 
717 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
718 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
719 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
720 		unsigned int j = 0;
721 
722 		/*
723 		 * Features here must be sorted in descending order with respect
724 		 * to their shift values and should not overlap with each other.
725 		 */
726 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
727 			unsigned int width = ftr_reg->ftr_bits[j].width;
728 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
729 			unsigned int prev_shift;
730 
731 			WARN((shift  + width) > 64,
732 				"%s has invalid feature at shift %d\n",
733 				ftr_reg->name, shift);
734 
735 			/*
736 			 * Skip the first feature. There is nothing to
737 			 * compare against for now.
738 			 */
739 			if (j == 0)
740 				continue;
741 
742 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
743 			WARN((shift + width) > prev_shift,
744 				"%s has feature overlap at shift %d\n",
745 				ftr_reg->name, shift);
746 		}
747 
748 		/*
749 		 * Skip the first register. There is nothing to
750 		 * compare against for now.
751 		 */
752 		if (i == 0)
753 			continue;
754 		/*
755 		 * Registers here must be sorted in ascending order with respect
756 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
757 		 * to work correctly.
758 		 */
759 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
760 	}
761 }
762 
763 /*
764  * Initialise the CPU feature register from Boot CPU values.
765  * Also initiliases the strict_mask for the register.
766  * Any bits that are not covered by an arm64_ftr_bits entry are considered
767  * RES0 for the system-wide value, and must strictly match.
768  */
769 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
770 {
771 	u64 val = 0;
772 	u64 strict_mask = ~0x0ULL;
773 	u64 user_mask = 0;
774 	u64 valid_mask = 0;
775 
776 	const struct arm64_ftr_bits *ftrp;
777 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
778 
779 	if (!reg)
780 		return;
781 
782 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
783 		u64 ftr_mask = arm64_ftr_mask(ftrp);
784 		s64 ftr_new = arm64_ftr_value(ftrp, new);
785 		s64 ftr_ovr = arm64_ftr_value(ftrp, reg->override->val);
786 
787 		if ((ftr_mask & reg->override->mask) == ftr_mask) {
788 			s64 tmp = arm64_ftr_safe_value(ftrp, ftr_ovr, ftr_new);
789 			char *str = NULL;
790 
791 			if (ftr_ovr != tmp) {
792 				/* Unsafe, remove the override */
793 				reg->override->mask &= ~ftr_mask;
794 				reg->override->val &= ~ftr_mask;
795 				tmp = ftr_ovr;
796 				str = "ignoring override";
797 			} else if (ftr_new != tmp) {
798 				/* Override was valid */
799 				ftr_new = tmp;
800 				str = "forced";
801 			} else if (ftr_ovr == tmp) {
802 				/* Override was the safe value */
803 				str = "already set";
804 			}
805 
806 			if (str)
807 				pr_warn("%s[%d:%d]: %s to %llx\n",
808 					reg->name,
809 					ftrp->shift + ftrp->width - 1,
810 					ftrp->shift, str, tmp);
811 		} else if ((ftr_mask & reg->override->val) == ftr_mask) {
812 			reg->override->val &= ~ftr_mask;
813 			pr_warn("%s[%d:%d]: impossible override, ignored\n",
814 				reg->name,
815 				ftrp->shift + ftrp->width - 1,
816 				ftrp->shift);
817 		}
818 
819 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
820 
821 		valid_mask |= ftr_mask;
822 		if (!ftrp->strict)
823 			strict_mask &= ~ftr_mask;
824 		if (ftrp->visible)
825 			user_mask |= ftr_mask;
826 		else
827 			reg->user_val = arm64_ftr_set_value(ftrp,
828 							    reg->user_val,
829 							    ftrp->safe_val);
830 	}
831 
832 	val &= valid_mask;
833 
834 	reg->sys_val = val;
835 	reg->strict_mask = strict_mask;
836 	reg->user_mask = user_mask;
837 }
838 
839 extern const struct arm64_cpu_capabilities arm64_errata[];
840 static const struct arm64_cpu_capabilities arm64_features[];
841 
842 static void __init
843 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
844 {
845 	for (; caps->matches; caps++) {
846 		if (WARN(caps->capability >= ARM64_NCAPS,
847 			"Invalid capability %d\n", caps->capability))
848 			continue;
849 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
850 			"Duplicate entry for capability %d\n",
851 			caps->capability))
852 			continue;
853 		cpu_hwcaps_ptrs[caps->capability] = caps;
854 	}
855 }
856 
857 static void __init init_cpu_hwcaps_indirect_list(void)
858 {
859 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
860 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
861 }
862 
863 static void __init setup_boot_cpu_capabilities(void);
864 
865 void __init init_cpu_features(struct cpuinfo_arm64 *info)
866 {
867 	/* Before we start using the tables, make sure it is sorted */
868 	sort_ftr_regs();
869 
870 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
871 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
872 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
873 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
874 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
875 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
876 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
877 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
878 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
879 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
880 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
881 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
882 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
883 
884 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
885 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
886 		init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
887 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
888 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
889 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
890 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
891 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
892 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
893 		init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
894 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
895 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
896 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
897 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
898 		init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
899 		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
900 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
901 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
902 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
903 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
904 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
905 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
906 	}
907 
908 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
909 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
910 		sve_init_vq_map();
911 	}
912 
913 	/*
914 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
915 	 * before we handle the boot CPU below.
916 	 */
917 	init_cpu_hwcaps_indirect_list();
918 
919 	/*
920 	 * Detect and enable early CPU capabilities based on the boot CPU,
921 	 * after we have initialised the CPU feature infrastructure.
922 	 */
923 	setup_boot_cpu_capabilities();
924 }
925 
926 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
927 {
928 	const struct arm64_ftr_bits *ftrp;
929 
930 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
931 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
932 		s64 ftr_new = arm64_ftr_value(ftrp, new);
933 
934 		if (ftr_cur == ftr_new)
935 			continue;
936 		/* Find a safe value */
937 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
938 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
939 	}
940 
941 }
942 
943 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
944 {
945 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
946 
947 	if (!regp)
948 		return 0;
949 
950 	update_cpu_ftr_reg(regp, val);
951 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
952 		return 0;
953 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
954 			regp->name, boot, cpu, val);
955 	return 1;
956 }
957 
958 static void relax_cpu_ftr_reg(u32 sys_id, int field)
959 {
960 	const struct arm64_ftr_bits *ftrp;
961 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
962 
963 	if (!regp)
964 		return;
965 
966 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
967 		if (ftrp->shift == field) {
968 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
969 			break;
970 		}
971 	}
972 
973 	/* Bogus field? */
974 	WARN_ON(!ftrp->width);
975 }
976 
977 static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
978 				     struct cpuinfo_arm64 *boot)
979 {
980 	int taint = 0;
981 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
982 
983 	/*
984 	 * If we don't have AArch32 at all then skip the checks entirely
985 	 * as the register values may be UNKNOWN and we're not going to be
986 	 * using them for anything.
987 	 */
988 	if (!id_aa64pfr0_32bit_el0(pfr0))
989 		return taint;
990 
991 	/*
992 	 * If we don't have AArch32 at EL1, then relax the strictness of
993 	 * EL1-dependent register fields to avoid spurious sanity check fails.
994 	 */
995 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
996 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
997 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
998 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
999 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
1000 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
1001 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
1002 	}
1003 
1004 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
1005 				      info->reg_id_dfr0, boot->reg_id_dfr0);
1006 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
1007 				      info->reg_id_dfr1, boot->reg_id_dfr1);
1008 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
1009 				      info->reg_id_isar0, boot->reg_id_isar0);
1010 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
1011 				      info->reg_id_isar1, boot->reg_id_isar1);
1012 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
1013 				      info->reg_id_isar2, boot->reg_id_isar2);
1014 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
1015 				      info->reg_id_isar3, boot->reg_id_isar3);
1016 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
1017 				      info->reg_id_isar4, boot->reg_id_isar4);
1018 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
1019 				      info->reg_id_isar5, boot->reg_id_isar5);
1020 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
1021 				      info->reg_id_isar6, boot->reg_id_isar6);
1022 
1023 	/*
1024 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
1025 	 * ACTLR formats could differ across CPUs and therefore would have to
1026 	 * be trapped for virtualization anyway.
1027 	 */
1028 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
1029 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
1030 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
1031 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
1032 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
1033 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
1034 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
1035 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
1036 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
1037 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
1038 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
1039 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
1040 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
1041 				      info->reg_id_pfr0, boot->reg_id_pfr0);
1042 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
1043 				      info->reg_id_pfr1, boot->reg_id_pfr1);
1044 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
1045 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1046 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1047 				      info->reg_mvfr0, boot->reg_mvfr0);
1048 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1049 				      info->reg_mvfr1, boot->reg_mvfr1);
1050 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1051 				      info->reg_mvfr2, boot->reg_mvfr2);
1052 
1053 	return taint;
1054 }
1055 
1056 /*
1057  * Update system wide CPU feature registers with the values from a
1058  * non-boot CPU. Also performs SANITY checks to make sure that there
1059  * aren't any insane variations from that of the boot CPU.
1060  */
1061 void update_cpu_features(int cpu,
1062 			 struct cpuinfo_arm64 *info,
1063 			 struct cpuinfo_arm64 *boot)
1064 {
1065 	int taint = 0;
1066 
1067 	/*
1068 	 * The kernel can handle differing I-cache policies, but otherwise
1069 	 * caches should look identical. Userspace JITs will make use of
1070 	 * *minLine.
1071 	 */
1072 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1073 				      info->reg_ctr, boot->reg_ctr);
1074 
1075 	/*
1076 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1077 	 * could result in too much or too little memory being zeroed if a
1078 	 * process is preempted and migrated between CPUs.
1079 	 */
1080 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1081 				      info->reg_dczid, boot->reg_dczid);
1082 
1083 	/* If different, timekeeping will be broken (especially with KVM) */
1084 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1085 				      info->reg_cntfrq, boot->reg_cntfrq);
1086 
1087 	/*
1088 	 * The kernel uses self-hosted debug features and expects CPUs to
1089 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1090 	 * and BRPs to be identical.
1091 	 * ID_AA64DFR1 is currently RES0.
1092 	 */
1093 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1094 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1095 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1096 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1097 	/*
1098 	 * Even in big.LITTLE, processors should be identical instruction-set
1099 	 * wise.
1100 	 */
1101 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1102 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1103 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1104 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1105 
1106 	/*
1107 	 * Differing PARange support is fine as long as all peripherals and
1108 	 * memory are mapped within the minimum PARange of all CPUs.
1109 	 * Linux should not care about secure memory.
1110 	 */
1111 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1112 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1113 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1114 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1115 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1116 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1117 
1118 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1119 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1120 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1121 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1122 
1123 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1124 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1125 
1126 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1127 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1128 					info->reg_zcr, boot->reg_zcr);
1129 
1130 		/* Probe vector lengths, unless we already gave up on SVE */
1131 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1132 		    !system_capabilities_finalized())
1133 			sve_update_vq_map();
1134 	}
1135 
1136 	/*
1137 	 * This relies on a sanitised view of the AArch64 ID registers
1138 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1139 	 */
1140 	taint |= update_32bit_cpu_features(cpu, info, boot);
1141 
1142 	/*
1143 	 * Mismatched CPU features are a recipe for disaster. Don't even
1144 	 * pretend to support them.
1145 	 */
1146 	if (taint) {
1147 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1148 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1149 	}
1150 }
1151 
1152 u64 read_sanitised_ftr_reg(u32 id)
1153 {
1154 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1155 
1156 	if (!regp)
1157 		return 0;
1158 	return regp->sys_val;
1159 }
1160 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
1161 
1162 #define read_sysreg_case(r)	\
1163 	case r:		val = read_sysreg_s(r); break;
1164 
1165 /*
1166  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1167  * Read the system register on the current CPU
1168  */
1169 u64 __read_sysreg_by_encoding(u32 sys_id)
1170 {
1171 	struct arm64_ftr_reg *regp;
1172 	u64 val;
1173 
1174 	switch (sys_id) {
1175 	read_sysreg_case(SYS_ID_PFR0_EL1);
1176 	read_sysreg_case(SYS_ID_PFR1_EL1);
1177 	read_sysreg_case(SYS_ID_PFR2_EL1);
1178 	read_sysreg_case(SYS_ID_DFR0_EL1);
1179 	read_sysreg_case(SYS_ID_DFR1_EL1);
1180 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1181 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1182 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1183 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1184 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1185 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1186 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1187 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1188 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1189 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1190 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1191 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1192 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1193 	read_sysreg_case(SYS_MVFR0_EL1);
1194 	read_sysreg_case(SYS_MVFR1_EL1);
1195 	read_sysreg_case(SYS_MVFR2_EL1);
1196 
1197 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1198 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1199 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1200 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1201 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1202 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1203 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1204 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1205 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1206 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1207 
1208 	read_sysreg_case(SYS_CNTFRQ_EL0);
1209 	read_sysreg_case(SYS_CTR_EL0);
1210 	read_sysreg_case(SYS_DCZID_EL0);
1211 
1212 	default:
1213 		BUG();
1214 		return 0;
1215 	}
1216 
1217 	regp  = get_arm64_ftr_reg(sys_id);
1218 	if (regp) {
1219 		val &= ~regp->override->mask;
1220 		val |= (regp->override->val & regp->override->mask);
1221 	}
1222 
1223 	return val;
1224 }
1225 
1226 #include <linux/irqchip/arm-gic-v3.h>
1227 
1228 static bool
1229 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1230 {
1231 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
1232 
1233 	return val >= entry->min_field_value;
1234 }
1235 
1236 static bool
1237 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1238 {
1239 	u64 val;
1240 
1241 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1242 	if (scope == SCOPE_SYSTEM)
1243 		val = read_sanitised_ftr_reg(entry->sys_reg);
1244 	else
1245 		val = __read_sysreg_by_encoding(entry->sys_reg);
1246 
1247 	return feature_matches(val, entry);
1248 }
1249 
1250 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1251 {
1252 	bool has_sre;
1253 
1254 	if (!has_cpuid_feature(entry, scope))
1255 		return false;
1256 
1257 	has_sre = gic_enable_sre();
1258 	if (!has_sre)
1259 		pr_warn_once("%s present but disabled by higher exception level\n",
1260 			     entry->desc);
1261 
1262 	return has_sre;
1263 }
1264 
1265 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1266 {
1267 	u32 midr = read_cpuid_id();
1268 
1269 	/* Cavium ThunderX pass 1.x and 2.x */
1270 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1271 		MIDR_CPU_VAR_REV(0, 0),
1272 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1273 }
1274 
1275 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1276 {
1277 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1278 
1279 	return cpuid_feature_extract_signed_field(pfr0,
1280 					ID_AA64PFR0_FP_SHIFT) < 0;
1281 }
1282 
1283 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1284 			  int scope)
1285 {
1286 	u64 ctr;
1287 
1288 	if (scope == SCOPE_SYSTEM)
1289 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1290 	else
1291 		ctr = read_cpuid_effective_cachetype();
1292 
1293 	return ctr & BIT(CTR_IDC_SHIFT);
1294 }
1295 
1296 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1297 {
1298 	/*
1299 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1300 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1301 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1302 	 * value.
1303 	 */
1304 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1305 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1306 }
1307 
1308 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1309 			  int scope)
1310 {
1311 	u64 ctr;
1312 
1313 	if (scope == SCOPE_SYSTEM)
1314 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1315 	else
1316 		ctr = read_cpuid_cachetype();
1317 
1318 	return ctr & BIT(CTR_DIC_SHIFT);
1319 }
1320 
1321 static bool __maybe_unused
1322 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1323 {
1324 	/*
1325 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1326 	 * may share TLB entries with a CPU stuck in the crashed
1327 	 * kernel.
1328 	 */
1329 	if (is_kdump_kernel())
1330 		return false;
1331 
1332 	if (cpus_have_const_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
1333 		return false;
1334 
1335 	return has_cpuid_feature(entry, scope);
1336 }
1337 
1338 /*
1339  * This check is triggered during the early boot before the cpufeature
1340  * is initialised. Checking the status on the local CPU allows the boot
1341  * CPU to detect the need for non-global mappings and thus avoiding a
1342  * pagetable re-write after all the CPUs are booted. This check will be
1343  * anyway run on individual CPUs, allowing us to get the consistent
1344  * state once the SMP CPUs are up and thus make the switch to non-global
1345  * mappings if required.
1346  */
1347 bool kaslr_requires_kpti(void)
1348 {
1349 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1350 		return false;
1351 
1352 	/*
1353 	 * E0PD does a similar job to KPTI so can be used instead
1354 	 * where available.
1355 	 */
1356 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1357 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1358 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1359 						ID_AA64MMFR2_E0PD_SHIFT))
1360 			return false;
1361 	}
1362 
1363 	/*
1364 	 * Systems affected by Cavium erratum 24756 are incompatible
1365 	 * with KPTI.
1366 	 */
1367 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1368 		extern const struct midr_range cavium_erratum_27456_cpus[];
1369 
1370 		if (is_midr_in_range_list(read_cpuid_id(),
1371 					  cavium_erratum_27456_cpus))
1372 			return false;
1373 	}
1374 
1375 	return kaslr_offset() > 0;
1376 }
1377 
1378 static bool __meltdown_safe = true;
1379 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1380 
1381 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1382 				int scope)
1383 {
1384 	/* List of CPUs that are not vulnerable and don't need KPTI */
1385 	static const struct midr_range kpti_safe_list[] = {
1386 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1387 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1388 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1389 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1390 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1391 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1392 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1393 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1394 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1395 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1396 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1397 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_GOLD),
1398 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
1399 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1400 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1401 		{ /* sentinel */ }
1402 	};
1403 	char const *str = "kpti command line option";
1404 	bool meltdown_safe;
1405 
1406 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1407 
1408 	/* Defer to CPU feature registers */
1409 	if (has_cpuid_feature(entry, scope))
1410 		meltdown_safe = true;
1411 
1412 	if (!meltdown_safe)
1413 		__meltdown_safe = false;
1414 
1415 	/*
1416 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1417 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1418 	 * ends as well as you might imagine. Don't even try.
1419 	 */
1420 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1421 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1422 		__kpti_forced = -1;
1423 	}
1424 
1425 	/* Useful for KASLR robustness */
1426 	if (kaslr_requires_kpti()) {
1427 		if (!__kpti_forced) {
1428 			str = "KASLR";
1429 			__kpti_forced = 1;
1430 		}
1431 	}
1432 
1433 	if (cpu_mitigations_off() && !__kpti_forced) {
1434 		str = "mitigations=off";
1435 		__kpti_forced = -1;
1436 	}
1437 
1438 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1439 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1440 		return false;
1441 	}
1442 
1443 	/* Forced? */
1444 	if (__kpti_forced) {
1445 		pr_info_once("kernel page table isolation forced %s by %s\n",
1446 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1447 		return __kpti_forced > 0;
1448 	}
1449 
1450 	return !meltdown_safe;
1451 }
1452 
1453 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1454 static void __nocfi
1455 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1456 {
1457 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1458 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1459 	kpti_remap_fn *remap_fn;
1460 
1461 	int cpu = smp_processor_id();
1462 
1463 	/*
1464 	 * We don't need to rewrite the page-tables if either we've done
1465 	 * it already or we have KASLR enabled and therefore have not
1466 	 * created any global mappings at all.
1467 	 */
1468 	if (arm64_use_ng_mappings)
1469 		return;
1470 
1471 	remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));
1472 
1473 	cpu_install_idmap();
1474 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1475 	cpu_uninstall_idmap();
1476 
1477 	if (!cpu)
1478 		arm64_use_ng_mappings = true;
1479 
1480 	return;
1481 }
1482 #else
1483 static void
1484 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1485 {
1486 }
1487 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1488 
1489 static int __init parse_kpti(char *str)
1490 {
1491 	bool enabled;
1492 	int ret = strtobool(str, &enabled);
1493 
1494 	if (ret)
1495 		return ret;
1496 
1497 	__kpti_forced = enabled ? 1 : -1;
1498 	return 0;
1499 }
1500 early_param("kpti", parse_kpti);
1501 
1502 #ifdef CONFIG_ARM64_HW_AFDBM
1503 static inline void __cpu_enable_hw_dbm(void)
1504 {
1505 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1506 
1507 	write_sysreg(tcr, tcr_el1);
1508 	isb();
1509 	local_flush_tlb_all();
1510 }
1511 
1512 static bool cpu_has_broken_dbm(void)
1513 {
1514 	/* List of CPUs which have broken DBM support. */
1515 	static const struct midr_range cpus[] = {
1516 #ifdef CONFIG_ARM64_ERRATUM_1024718
1517 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1518 		/* Kryo4xx Silver (rdpe => r1p0) */
1519 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1520 #endif
1521 		{},
1522 	};
1523 
1524 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1525 }
1526 
1527 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1528 {
1529 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1530 	       !cpu_has_broken_dbm();
1531 }
1532 
1533 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1534 {
1535 	if (cpu_can_use_dbm(cap))
1536 		__cpu_enable_hw_dbm();
1537 }
1538 
1539 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1540 		       int __unused)
1541 {
1542 	static bool detected = false;
1543 	/*
1544 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1545 	 * run a mix of CPUs with and without the feature. So, we
1546 	 * unconditionally enable the capability to allow any late CPU
1547 	 * to use the feature. We only enable the control bits on the
1548 	 * CPU, if it actually supports.
1549 	 *
1550 	 * We have to make sure we print the "feature" detection only
1551 	 * when at least one CPU actually uses it. So check if this CPU
1552 	 * can actually use it and print the message exactly once.
1553 	 *
1554 	 * This is safe as all CPUs (including secondary CPUs - due to the
1555 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1556 	 * goes through the "matches" check exactly once. Also if a CPU
1557 	 * matches the criteria, it is guaranteed that the CPU will turn
1558 	 * the DBM on, as the capability is unconditionally enabled.
1559 	 */
1560 	if (!detected && cpu_can_use_dbm(cap)) {
1561 		detected = true;
1562 		pr_info("detected: Hardware dirty bit management\n");
1563 	}
1564 
1565 	return true;
1566 }
1567 
1568 #endif
1569 
1570 #ifdef CONFIG_ARM64_AMU_EXTN
1571 
1572 /*
1573  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1574  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1575  * information regarding all the events that it supports. When a CPU bit is
1576  * set in the cpumask, the user of this feature can only rely on the presence
1577  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1578  * counters are enabled or access to these counters is enabled by code
1579  * executed at higher exception levels (firmware).
1580  */
1581 static struct cpumask amu_cpus __read_mostly;
1582 
1583 bool cpu_has_amu_feat(int cpu)
1584 {
1585 	return cpumask_test_cpu(cpu, &amu_cpus);
1586 }
1587 
1588 int get_cpu_with_amu_feat(void)
1589 {
1590 	return cpumask_any(&amu_cpus);
1591 }
1592 
1593 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1594 {
1595 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1596 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1597 			smp_processor_id());
1598 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1599 		update_freq_counters_refs();
1600 	}
1601 }
1602 
1603 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1604 		    int __unused)
1605 {
1606 	/*
1607 	 * The AMU extension is a non-conflicting feature: the kernel can
1608 	 * safely run a mix of CPUs with and without support for the
1609 	 * activity monitors extension. Therefore, unconditionally enable
1610 	 * the capability to allow any late CPU to use the feature.
1611 	 *
1612 	 * With this feature unconditionally enabled, the cpu_enable
1613 	 * function will be called for all CPUs that match the criteria,
1614 	 * including secondary and hotplugged, marking this feature as
1615 	 * present on that respective CPU. The enable function will also
1616 	 * print a detection message.
1617 	 */
1618 
1619 	return true;
1620 }
1621 #else
1622 int get_cpu_with_amu_feat(void)
1623 {
1624 	return nr_cpu_ids;
1625 }
1626 #endif
1627 
1628 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1629 {
1630 	return is_kernel_in_hyp_mode();
1631 }
1632 
1633 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1634 {
1635 	/*
1636 	 * Copy register values that aren't redirected by hardware.
1637 	 *
1638 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1639 	 * this value to tpidr_el2 before we patch the code. Once we've done
1640 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1641 	 * do anything here.
1642 	 */
1643 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1644 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1645 }
1646 
1647 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1648 {
1649 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1650 
1651 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1652 	WARN_ON(val & (7 << 27 | 7 << 21));
1653 }
1654 
1655 #ifdef CONFIG_ARM64_PAN
1656 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1657 {
1658 	/*
1659 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1660 	 * is discarded once we return from the exception.
1661 	 */
1662 	WARN_ON_ONCE(in_interrupt());
1663 
1664 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1665 	set_pstate_pan(1);
1666 }
1667 #endif /* CONFIG_ARM64_PAN */
1668 
1669 #ifdef CONFIG_ARM64_RAS_EXTN
1670 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1671 {
1672 	/* Firmware may have left a deferred SError in this register. */
1673 	write_sysreg_s(0, SYS_DISR_EL1);
1674 }
1675 #endif /* CONFIG_ARM64_RAS_EXTN */
1676 
1677 #ifdef CONFIG_ARM64_PTR_AUTH
1678 static bool has_address_auth_cpucap(const struct arm64_cpu_capabilities *entry, int scope)
1679 {
1680 	int boot_val, sec_val;
1681 
1682 	/* We don't expect to be called with SCOPE_SYSTEM */
1683 	WARN_ON(scope == SCOPE_SYSTEM);
1684 	/*
1685 	 * The ptr-auth feature levels are not intercompatible with lower
1686 	 * levels. Hence we must match ptr-auth feature level of the secondary
1687 	 * CPUs with that of the boot CPU. The level of boot cpu is fetched
1688 	 * from the sanitised register whereas direct register read is done for
1689 	 * the secondary CPUs.
1690 	 * The sanitised feature state is guaranteed to match that of the
1691 	 * boot CPU as a mismatched secondary CPU is parked before it gets
1692 	 * a chance to update the state, with the capability.
1693 	 */
1694 	boot_val = cpuid_feature_extract_field(read_sanitised_ftr_reg(entry->sys_reg),
1695 					       entry->field_pos, entry->sign);
1696 	if (scope & SCOPE_BOOT_CPU)
1697 		return boot_val >= entry->min_field_value;
1698 	/* Now check for the secondary CPUs with SCOPE_LOCAL_CPU scope */
1699 	sec_val = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg),
1700 					      entry->field_pos, entry->sign);
1701 	return sec_val == boot_val;
1702 }
1703 
1704 static bool has_address_auth_metacap(const struct arm64_cpu_capabilities *entry,
1705 				     int scope)
1706 {
1707 	return has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH], scope) ||
1708 	       has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_IMP_DEF], scope);
1709 }
1710 
1711 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1712 			     int __unused)
1713 {
1714 	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
1715 	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1716 }
1717 #endif /* CONFIG_ARM64_PTR_AUTH */
1718 
1719 #ifdef CONFIG_ARM64_E0PD
1720 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1721 {
1722 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1723 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1724 }
1725 #endif /* CONFIG_ARM64_E0PD */
1726 
1727 #ifdef CONFIG_ARM64_PSEUDO_NMI
1728 static bool enable_pseudo_nmi;
1729 
1730 static int __init early_enable_pseudo_nmi(char *p)
1731 {
1732 	return strtobool(p, &enable_pseudo_nmi);
1733 }
1734 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1735 
1736 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1737 				   int scope)
1738 {
1739 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1740 }
1741 #endif
1742 
1743 #ifdef CONFIG_ARM64_BTI
1744 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1745 {
1746 	/*
1747 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1748 	 * function entry points using BR is a requirement for
1749 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1750 	 * So, be strict and forbid other BRs using other registers to
1751 	 * jump onto a PACIxSP instruction:
1752 	 */
1753 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1754 	isb();
1755 }
1756 #endif /* CONFIG_ARM64_BTI */
1757 
1758 #ifdef CONFIG_ARM64_MTE
1759 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
1760 {
1761 	/*
1762 	 * Clear the tags in the zero page. This needs to be done via the
1763 	 * linear map which has the Tagged attribute.
1764 	 */
1765 	if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
1766 		mte_clear_page_tags(lm_alias(empty_zero_page));
1767 
1768 	kasan_init_hw_tags_cpu();
1769 }
1770 #endif /* CONFIG_ARM64_MTE */
1771 
1772 #ifdef CONFIG_KVM
1773 static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
1774 {
1775 	if (kvm_get_mode() != KVM_MODE_PROTECTED)
1776 		return false;
1777 
1778 	if (is_kernel_in_hyp_mode()) {
1779 		pr_warn("Protected KVM not available with VHE\n");
1780 		return false;
1781 	}
1782 
1783 	return true;
1784 }
1785 #endif /* CONFIG_KVM */
1786 
1787 /* Internal helper functions to match cpu capability type */
1788 static bool
1789 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1790 {
1791 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1792 }
1793 
1794 static bool
1795 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1796 {
1797 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1798 }
1799 
1800 static bool
1801 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1802 {
1803 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1804 }
1805 
1806 static const struct arm64_cpu_capabilities arm64_features[] = {
1807 	{
1808 		.desc = "GIC system register CPU interface",
1809 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1810 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1811 		.matches = has_useable_gicv3_cpuif,
1812 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1813 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1814 		.sign = FTR_UNSIGNED,
1815 		.min_field_value = 1,
1816 	},
1817 #ifdef CONFIG_ARM64_PAN
1818 	{
1819 		.desc = "Privileged Access Never",
1820 		.capability = ARM64_HAS_PAN,
1821 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1822 		.matches = has_cpuid_feature,
1823 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1824 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1825 		.sign = FTR_UNSIGNED,
1826 		.min_field_value = 1,
1827 		.cpu_enable = cpu_enable_pan,
1828 	},
1829 #endif /* CONFIG_ARM64_PAN */
1830 #ifdef CONFIG_ARM64_EPAN
1831 	{
1832 		.desc = "Enhanced Privileged Access Never",
1833 		.capability = ARM64_HAS_EPAN,
1834 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1835 		.matches = has_cpuid_feature,
1836 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1837 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1838 		.sign = FTR_UNSIGNED,
1839 		.min_field_value = 3,
1840 	},
1841 #endif /* CONFIG_ARM64_EPAN */
1842 #ifdef CONFIG_ARM64_LSE_ATOMICS
1843 	{
1844 		.desc = "LSE atomic instructions",
1845 		.capability = ARM64_HAS_LSE_ATOMICS,
1846 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1847 		.matches = has_cpuid_feature,
1848 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1849 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1850 		.sign = FTR_UNSIGNED,
1851 		.min_field_value = 2,
1852 	},
1853 #endif /* CONFIG_ARM64_LSE_ATOMICS */
1854 	{
1855 		.desc = "Software prefetching using PRFM",
1856 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1857 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1858 		.matches = has_no_hw_prefetch,
1859 	},
1860 	{
1861 		.desc = "Virtualization Host Extensions",
1862 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1863 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1864 		.matches = runs_at_el2,
1865 		.cpu_enable = cpu_copy_el2regs,
1866 	},
1867 	{
1868 		.desc = "32-bit EL0 Support",
1869 		.capability = ARM64_HAS_32BIT_EL0,
1870 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1871 		.matches = has_cpuid_feature,
1872 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1873 		.sign = FTR_UNSIGNED,
1874 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1875 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1876 	},
1877 #ifdef CONFIG_KVM
1878 	{
1879 		.desc = "32-bit EL1 Support",
1880 		.capability = ARM64_HAS_32BIT_EL1,
1881 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1882 		.matches = has_cpuid_feature,
1883 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1884 		.sign = FTR_UNSIGNED,
1885 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
1886 		.min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
1887 	},
1888 	{
1889 		.desc = "Protected KVM",
1890 		.capability = ARM64_KVM_PROTECTED_MODE,
1891 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1892 		.matches = is_kvm_protected_mode,
1893 	},
1894 #endif
1895 	{
1896 		.desc = "Kernel page table isolation (KPTI)",
1897 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1898 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1899 		/*
1900 		 * The ID feature fields below are used to indicate that
1901 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1902 		 * more details.
1903 		 */
1904 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1905 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1906 		.min_field_value = 1,
1907 		.matches = unmap_kernel_at_el0,
1908 		.cpu_enable = kpti_install_ng_mappings,
1909 	},
1910 	{
1911 		/* FP/SIMD is not implemented */
1912 		.capability = ARM64_HAS_NO_FPSIMD,
1913 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1914 		.min_field_value = 0,
1915 		.matches = has_no_fpsimd,
1916 	},
1917 #ifdef CONFIG_ARM64_PMEM
1918 	{
1919 		.desc = "Data cache clean to Point of Persistence",
1920 		.capability = ARM64_HAS_DCPOP,
1921 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1922 		.matches = has_cpuid_feature,
1923 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1924 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1925 		.min_field_value = 1,
1926 	},
1927 	{
1928 		.desc = "Data cache clean to Point of Deep Persistence",
1929 		.capability = ARM64_HAS_DCPODP,
1930 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1931 		.matches = has_cpuid_feature,
1932 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1933 		.sign = FTR_UNSIGNED,
1934 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1935 		.min_field_value = 2,
1936 	},
1937 #endif
1938 #ifdef CONFIG_ARM64_SVE
1939 	{
1940 		.desc = "Scalable Vector Extension",
1941 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1942 		.capability = ARM64_SVE,
1943 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1944 		.sign = FTR_UNSIGNED,
1945 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1946 		.min_field_value = ID_AA64PFR0_SVE,
1947 		.matches = has_cpuid_feature,
1948 		.cpu_enable = sve_kernel_enable,
1949 	},
1950 #endif /* CONFIG_ARM64_SVE */
1951 #ifdef CONFIG_ARM64_RAS_EXTN
1952 	{
1953 		.desc = "RAS Extension Support",
1954 		.capability = ARM64_HAS_RAS_EXTN,
1955 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1956 		.matches = has_cpuid_feature,
1957 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1958 		.sign = FTR_UNSIGNED,
1959 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1960 		.min_field_value = ID_AA64PFR0_RAS_V1,
1961 		.cpu_enable = cpu_clear_disr,
1962 	},
1963 #endif /* CONFIG_ARM64_RAS_EXTN */
1964 #ifdef CONFIG_ARM64_AMU_EXTN
1965 	{
1966 		/*
1967 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
1968 		 * Therefore, don't provide .desc as we don't want the detection
1969 		 * message to be shown until at least one CPU is detected to
1970 		 * support the feature.
1971 		 */
1972 		.capability = ARM64_HAS_AMU_EXTN,
1973 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1974 		.matches = has_amu,
1975 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1976 		.sign = FTR_UNSIGNED,
1977 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
1978 		.min_field_value = ID_AA64PFR0_AMU,
1979 		.cpu_enable = cpu_amu_enable,
1980 	},
1981 #endif /* CONFIG_ARM64_AMU_EXTN */
1982 	{
1983 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1984 		.capability = ARM64_HAS_CACHE_IDC,
1985 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1986 		.matches = has_cache_idc,
1987 		.cpu_enable = cpu_emulate_effective_ctr,
1988 	},
1989 	{
1990 		.desc = "Instruction cache invalidation not required for I/D coherence",
1991 		.capability = ARM64_HAS_CACHE_DIC,
1992 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1993 		.matches = has_cache_dic,
1994 	},
1995 	{
1996 		.desc = "Stage-2 Force Write-Back",
1997 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1998 		.capability = ARM64_HAS_STAGE2_FWB,
1999 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2000 		.sign = FTR_UNSIGNED,
2001 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
2002 		.min_field_value = 1,
2003 		.matches = has_cpuid_feature,
2004 		.cpu_enable = cpu_has_fwb,
2005 	},
2006 	{
2007 		.desc = "ARMv8.4 Translation Table Level",
2008 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2009 		.capability = ARM64_HAS_ARMv8_4_TTL,
2010 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2011 		.sign = FTR_UNSIGNED,
2012 		.field_pos = ID_AA64MMFR2_TTL_SHIFT,
2013 		.min_field_value = 1,
2014 		.matches = has_cpuid_feature,
2015 	},
2016 	{
2017 		.desc = "TLB range maintenance instructions",
2018 		.capability = ARM64_HAS_TLB_RANGE,
2019 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2020 		.matches = has_cpuid_feature,
2021 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2022 		.field_pos = ID_AA64ISAR0_TLB_SHIFT,
2023 		.sign = FTR_UNSIGNED,
2024 		.min_field_value = ID_AA64ISAR0_TLB_RANGE,
2025 	},
2026 #ifdef CONFIG_ARM64_HW_AFDBM
2027 	{
2028 		/*
2029 		 * Since we turn this on always, we don't want the user to
2030 		 * think that the feature is available when it may not be.
2031 		 * So hide the description.
2032 		 *
2033 		 * .desc = "Hardware pagetable Dirty Bit Management",
2034 		 *
2035 		 */
2036 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
2037 		.capability = ARM64_HW_DBM,
2038 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
2039 		.sign = FTR_UNSIGNED,
2040 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
2041 		.min_field_value = 2,
2042 		.matches = has_hw_dbm,
2043 		.cpu_enable = cpu_enable_hw_dbm,
2044 	},
2045 #endif
2046 	{
2047 		.desc = "CRC32 instructions",
2048 		.capability = ARM64_HAS_CRC32,
2049 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2050 		.matches = has_cpuid_feature,
2051 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2052 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
2053 		.min_field_value = 1,
2054 	},
2055 	{
2056 		.desc = "Speculative Store Bypassing Safe (SSBS)",
2057 		.capability = ARM64_SSBS,
2058 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2059 		.matches = has_cpuid_feature,
2060 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2061 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
2062 		.sign = FTR_UNSIGNED,
2063 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
2064 	},
2065 #ifdef CONFIG_ARM64_CNP
2066 	{
2067 		.desc = "Common not Private translations",
2068 		.capability = ARM64_HAS_CNP,
2069 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2070 		.matches = has_useable_cnp,
2071 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2072 		.sign = FTR_UNSIGNED,
2073 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
2074 		.min_field_value = 1,
2075 		.cpu_enable = cpu_enable_cnp,
2076 	},
2077 #endif
2078 	{
2079 		.desc = "Speculation barrier (SB)",
2080 		.capability = ARM64_HAS_SB,
2081 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2082 		.matches = has_cpuid_feature,
2083 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2084 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
2085 		.sign = FTR_UNSIGNED,
2086 		.min_field_value = 1,
2087 	},
2088 #ifdef CONFIG_ARM64_PTR_AUTH
2089 	{
2090 		.desc = "Address authentication (architected algorithm)",
2091 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
2092 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2093 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2094 		.sign = FTR_UNSIGNED,
2095 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
2096 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
2097 		.matches = has_address_auth_cpucap,
2098 	},
2099 	{
2100 		.desc = "Address authentication (IMP DEF algorithm)",
2101 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2102 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2103 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2104 		.sign = FTR_UNSIGNED,
2105 		.field_pos = ID_AA64ISAR1_API_SHIFT,
2106 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
2107 		.matches = has_address_auth_cpucap,
2108 	},
2109 	{
2110 		.capability = ARM64_HAS_ADDRESS_AUTH,
2111 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2112 		.matches = has_address_auth_metacap,
2113 	},
2114 	{
2115 		.desc = "Generic authentication (architected algorithm)",
2116 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
2117 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2118 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2119 		.sign = FTR_UNSIGNED,
2120 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
2121 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
2122 		.matches = has_cpuid_feature,
2123 	},
2124 	{
2125 		.desc = "Generic authentication (IMP DEF algorithm)",
2126 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2127 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2128 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2129 		.sign = FTR_UNSIGNED,
2130 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
2131 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
2132 		.matches = has_cpuid_feature,
2133 	},
2134 	{
2135 		.capability = ARM64_HAS_GENERIC_AUTH,
2136 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2137 		.matches = has_generic_auth,
2138 	},
2139 #endif /* CONFIG_ARM64_PTR_AUTH */
2140 #ifdef CONFIG_ARM64_PSEUDO_NMI
2141 	{
2142 		/*
2143 		 * Depends on having GICv3
2144 		 */
2145 		.desc = "IRQ priority masking",
2146 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2147 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2148 		.matches = can_use_gic_priorities,
2149 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2150 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2151 		.sign = FTR_UNSIGNED,
2152 		.min_field_value = 1,
2153 	},
2154 #endif
2155 #ifdef CONFIG_ARM64_E0PD
2156 	{
2157 		.desc = "E0PD",
2158 		.capability = ARM64_HAS_E0PD,
2159 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2160 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2161 		.sign = FTR_UNSIGNED,
2162 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2163 		.matches = has_cpuid_feature,
2164 		.min_field_value = 1,
2165 		.cpu_enable = cpu_enable_e0pd,
2166 	},
2167 #endif
2168 #ifdef CONFIG_ARCH_RANDOM
2169 	{
2170 		.desc = "Random Number Generator",
2171 		.capability = ARM64_HAS_RNG,
2172 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2173 		.matches = has_cpuid_feature,
2174 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2175 		.field_pos = ID_AA64ISAR0_RNDR_SHIFT,
2176 		.sign = FTR_UNSIGNED,
2177 		.min_field_value = 1,
2178 	},
2179 #endif
2180 #ifdef CONFIG_ARM64_BTI
2181 	{
2182 		.desc = "Branch Target Identification",
2183 		.capability = ARM64_BTI,
2184 #ifdef CONFIG_ARM64_BTI_KERNEL
2185 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2186 #else
2187 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2188 #endif
2189 		.matches = has_cpuid_feature,
2190 		.cpu_enable = bti_enable,
2191 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2192 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2193 		.min_field_value = ID_AA64PFR1_BT_BTI,
2194 		.sign = FTR_UNSIGNED,
2195 	},
2196 #endif
2197 #ifdef CONFIG_ARM64_MTE
2198 	{
2199 		.desc = "Memory Tagging Extension",
2200 		.capability = ARM64_MTE,
2201 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2202 		.matches = has_cpuid_feature,
2203 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2204 		.field_pos = ID_AA64PFR1_MTE_SHIFT,
2205 		.min_field_value = ID_AA64PFR1_MTE,
2206 		.sign = FTR_UNSIGNED,
2207 		.cpu_enable = cpu_enable_mte,
2208 	},
2209 #endif /* CONFIG_ARM64_MTE */
2210 	{
2211 		.desc = "RCpc load-acquire (LDAPR)",
2212 		.capability = ARM64_HAS_LDAPR,
2213 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2214 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2215 		.sign = FTR_UNSIGNED,
2216 		.field_pos = ID_AA64ISAR1_LRCPC_SHIFT,
2217 		.matches = has_cpuid_feature,
2218 		.min_field_value = 1,
2219 	},
2220 	{},
2221 };
2222 
2223 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
2224 		.matches = has_cpuid_feature,					\
2225 		.sys_reg = reg,							\
2226 		.field_pos = field,						\
2227 		.sign = s,							\
2228 		.min_field_value = min_value,
2229 
2230 #define __HWCAP_CAP(name, cap_type, cap)					\
2231 		.desc = name,							\
2232 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2233 		.hwcap_type = cap_type,						\
2234 		.hwcap = cap,							\
2235 
2236 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
2237 	{									\
2238 		__HWCAP_CAP(#cap, cap_type, cap)				\
2239 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
2240 	}
2241 
2242 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2243 	{									\
2244 		__HWCAP_CAP(#cap, cap_type, cap)				\
2245 		.matches = cpucap_multi_entry_cap_matches,			\
2246 		.match_list = list,						\
2247 	}
2248 
2249 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2250 	{									\
2251 		__HWCAP_CAP(#cap, cap_type, cap)				\
2252 		.matches = match,						\
2253 	}
2254 
2255 #ifdef CONFIG_ARM64_PTR_AUTH
2256 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2257 	{
2258 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2259 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
2260 	},
2261 	{
2262 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2263 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2264 	},
2265 	{},
2266 };
2267 
2268 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2269 	{
2270 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2271 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2272 	},
2273 	{
2274 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2275 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2276 	},
2277 	{},
2278 };
2279 #endif
2280 
2281 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2282 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2283 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2284 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2285 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2286 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2287 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2288 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2289 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2290 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2291 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2292 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2293 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2294 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2295 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2296 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2297 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2298 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2299 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2300 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2301 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2302 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2303 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2304 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2305 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2306 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2307 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2308 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2309 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2310 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2311 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2312 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2313 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2314 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2315 #ifdef CONFIG_ARM64_SVE
2316 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2317 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2318 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2319 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2320 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2321 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2322 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2323 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2324 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2325 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2326 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2327 #endif
2328 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2329 #ifdef CONFIG_ARM64_BTI
2330 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2331 #endif
2332 #ifdef CONFIG_ARM64_PTR_AUTH
2333 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2334 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2335 #endif
2336 #ifdef CONFIG_ARM64_MTE
2337 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE),
2338 #endif /* CONFIG_ARM64_MTE */
2339 	{},
2340 };
2341 
2342 #ifdef CONFIG_COMPAT
2343 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2344 {
2345 	/*
2346 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2347 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2348 	 * check is future proof, by making sure value is non-zero.
2349 	 */
2350 	u32 mvfr1;
2351 
2352 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2353 	if (scope == SCOPE_SYSTEM)
2354 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2355 	else
2356 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2357 
2358 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2359 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2360 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2361 }
2362 #endif
2363 
2364 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2365 #ifdef CONFIG_COMPAT
2366 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2367 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2368 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2369 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2370 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2371 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2372 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2373 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2374 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2375 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2376 #endif
2377 	{},
2378 };
2379 
2380 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2381 {
2382 	switch (cap->hwcap_type) {
2383 	case CAP_HWCAP:
2384 		cpu_set_feature(cap->hwcap);
2385 		break;
2386 #ifdef CONFIG_COMPAT
2387 	case CAP_COMPAT_HWCAP:
2388 		compat_elf_hwcap |= (u32)cap->hwcap;
2389 		break;
2390 	case CAP_COMPAT_HWCAP2:
2391 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2392 		break;
2393 #endif
2394 	default:
2395 		WARN_ON(1);
2396 		break;
2397 	}
2398 }
2399 
2400 /* Check if we have a particular HWCAP enabled */
2401 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2402 {
2403 	bool rc;
2404 
2405 	switch (cap->hwcap_type) {
2406 	case CAP_HWCAP:
2407 		rc = cpu_have_feature(cap->hwcap);
2408 		break;
2409 #ifdef CONFIG_COMPAT
2410 	case CAP_COMPAT_HWCAP:
2411 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2412 		break;
2413 	case CAP_COMPAT_HWCAP2:
2414 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2415 		break;
2416 #endif
2417 	default:
2418 		WARN_ON(1);
2419 		rc = false;
2420 	}
2421 
2422 	return rc;
2423 }
2424 
2425 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2426 {
2427 	/* We support emulation of accesses to CPU ID feature registers */
2428 	cpu_set_named_feature(CPUID);
2429 	for (; hwcaps->matches; hwcaps++)
2430 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2431 			cap_set_elf_hwcap(hwcaps);
2432 }
2433 
2434 static void update_cpu_capabilities(u16 scope_mask)
2435 {
2436 	int i;
2437 	const struct arm64_cpu_capabilities *caps;
2438 
2439 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2440 	for (i = 0; i < ARM64_NCAPS; i++) {
2441 		caps = cpu_hwcaps_ptrs[i];
2442 		if (!caps || !(caps->type & scope_mask) ||
2443 		    cpus_have_cap(caps->capability) ||
2444 		    !caps->matches(caps, cpucap_default_scope(caps)))
2445 			continue;
2446 
2447 		if (caps->desc)
2448 			pr_info("detected: %s\n", caps->desc);
2449 		cpus_set_cap(caps->capability);
2450 
2451 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2452 			set_bit(caps->capability, boot_capabilities);
2453 	}
2454 }
2455 
2456 /*
2457  * Enable all the available capabilities on this CPU. The capabilities
2458  * with BOOT_CPU scope are handled separately and hence skipped here.
2459  */
2460 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2461 {
2462 	int i;
2463 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2464 
2465 	for_each_available_cap(i) {
2466 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2467 
2468 		if (WARN_ON(!cap))
2469 			continue;
2470 
2471 		if (!(cap->type & non_boot_scope))
2472 			continue;
2473 
2474 		if (cap->cpu_enable)
2475 			cap->cpu_enable(cap);
2476 	}
2477 	return 0;
2478 }
2479 
2480 /*
2481  * Run through the enabled capabilities and enable() it on all active
2482  * CPUs
2483  */
2484 static void __init enable_cpu_capabilities(u16 scope_mask)
2485 {
2486 	int i;
2487 	const struct arm64_cpu_capabilities *caps;
2488 	bool boot_scope;
2489 
2490 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2491 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2492 
2493 	for (i = 0; i < ARM64_NCAPS; i++) {
2494 		unsigned int num;
2495 
2496 		caps = cpu_hwcaps_ptrs[i];
2497 		if (!caps || !(caps->type & scope_mask))
2498 			continue;
2499 		num = caps->capability;
2500 		if (!cpus_have_cap(num))
2501 			continue;
2502 
2503 		/* Ensure cpus_have_const_cap(num) works */
2504 		static_branch_enable(&cpu_hwcap_keys[num]);
2505 
2506 		if (boot_scope && caps->cpu_enable)
2507 			/*
2508 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2509 			 * before any secondary CPU boots. Thus, each secondary
2510 			 * will enable the capability as appropriate via
2511 			 * check_local_cpu_capabilities(). The only exception is
2512 			 * the boot CPU, for which the capability must be
2513 			 * enabled here. This approach avoids costly
2514 			 * stop_machine() calls for this case.
2515 			 */
2516 			caps->cpu_enable(caps);
2517 	}
2518 
2519 	/*
2520 	 * For all non-boot scope capabilities, use stop_machine()
2521 	 * as it schedules the work allowing us to modify PSTATE,
2522 	 * instead of on_each_cpu() which uses an IPI, giving us a
2523 	 * PSTATE that disappears when we return.
2524 	 */
2525 	if (!boot_scope)
2526 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2527 			     NULL, cpu_online_mask);
2528 }
2529 
2530 /*
2531  * Run through the list of capabilities to check for conflicts.
2532  * If the system has already detected a capability, take necessary
2533  * action on this CPU.
2534  */
2535 static void verify_local_cpu_caps(u16 scope_mask)
2536 {
2537 	int i;
2538 	bool cpu_has_cap, system_has_cap;
2539 	const struct arm64_cpu_capabilities *caps;
2540 
2541 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2542 
2543 	for (i = 0; i < ARM64_NCAPS; i++) {
2544 		caps = cpu_hwcaps_ptrs[i];
2545 		if (!caps || !(caps->type & scope_mask))
2546 			continue;
2547 
2548 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2549 		system_has_cap = cpus_have_cap(caps->capability);
2550 
2551 		if (system_has_cap) {
2552 			/*
2553 			 * Check if the new CPU misses an advertised feature,
2554 			 * which is not safe to miss.
2555 			 */
2556 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2557 				break;
2558 			/*
2559 			 * We have to issue cpu_enable() irrespective of
2560 			 * whether the CPU has it or not, as it is enabeld
2561 			 * system wide. It is upto the call back to take
2562 			 * appropriate action on this CPU.
2563 			 */
2564 			if (caps->cpu_enable)
2565 				caps->cpu_enable(caps);
2566 		} else {
2567 			/*
2568 			 * Check if the CPU has this capability if it isn't
2569 			 * safe to have when the system doesn't.
2570 			 */
2571 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2572 				break;
2573 		}
2574 	}
2575 
2576 	if (i < ARM64_NCAPS) {
2577 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2578 			smp_processor_id(), caps->capability,
2579 			caps->desc, system_has_cap, cpu_has_cap);
2580 
2581 		if (cpucap_panic_on_conflict(caps))
2582 			cpu_panic_kernel();
2583 		else
2584 			cpu_die_early();
2585 	}
2586 }
2587 
2588 /*
2589  * Check for CPU features that are used in early boot
2590  * based on the Boot CPU value.
2591  */
2592 static void check_early_cpu_features(void)
2593 {
2594 	verify_cpu_asid_bits();
2595 
2596 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2597 }
2598 
2599 static void
2600 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2601 {
2602 
2603 	for (; caps->matches; caps++)
2604 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2605 			pr_crit("CPU%d: missing HWCAP: %s\n",
2606 					smp_processor_id(), caps->desc);
2607 			cpu_die_early();
2608 		}
2609 }
2610 
2611 static void verify_sve_features(void)
2612 {
2613 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2614 	u64 zcr = read_zcr_features();
2615 
2616 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2617 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2618 
2619 	if (len < safe_len || sve_verify_vq_map()) {
2620 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2621 			smp_processor_id());
2622 		cpu_die_early();
2623 	}
2624 
2625 	/* Add checks on other ZCR bits here if necessary */
2626 }
2627 
2628 static void verify_hyp_capabilities(void)
2629 {
2630 	u64 safe_mmfr1, mmfr0, mmfr1;
2631 	int parange, ipa_max;
2632 	unsigned int safe_vmid_bits, vmid_bits;
2633 
2634 	if (!IS_ENABLED(CONFIG_KVM))
2635 		return;
2636 
2637 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2638 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2639 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2640 
2641 	/* Verify VMID bits */
2642 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2643 	vmid_bits = get_vmid_bits(mmfr1);
2644 	if (vmid_bits < safe_vmid_bits) {
2645 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
2646 		cpu_die_early();
2647 	}
2648 
2649 	/* Verify IPA range */
2650 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
2651 				ID_AA64MMFR0_PARANGE_SHIFT);
2652 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
2653 	if (ipa_max < get_kvm_ipa_limit()) {
2654 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
2655 		cpu_die_early();
2656 	}
2657 }
2658 
2659 /*
2660  * Run through the enabled system capabilities and enable() it on this CPU.
2661  * The capabilities were decided based on the available CPUs at the boot time.
2662  * Any new CPU should match the system wide status of the capability. If the
2663  * new CPU doesn't have a capability which the system now has enabled, we
2664  * cannot do anything to fix it up and could cause unexpected failures. So
2665  * we park the CPU.
2666  */
2667 static void verify_local_cpu_capabilities(void)
2668 {
2669 	/*
2670 	 * The capabilities with SCOPE_BOOT_CPU are checked from
2671 	 * check_early_cpu_features(), as they need to be verified
2672 	 * on all secondary CPUs.
2673 	 */
2674 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2675 
2676 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
2677 
2678 	if (system_supports_32bit_el0())
2679 		verify_local_elf_hwcaps(compat_elf_hwcaps);
2680 
2681 	if (system_supports_sve())
2682 		verify_sve_features();
2683 
2684 	if (is_hyp_mode_available())
2685 		verify_hyp_capabilities();
2686 }
2687 
2688 void check_local_cpu_capabilities(void)
2689 {
2690 	/*
2691 	 * All secondary CPUs should conform to the early CPU features
2692 	 * in use by the kernel based on boot CPU.
2693 	 */
2694 	check_early_cpu_features();
2695 
2696 	/*
2697 	 * If we haven't finalised the system capabilities, this CPU gets
2698 	 * a chance to update the errata work arounds and local features.
2699 	 * Otherwise, this CPU should verify that it has all the system
2700 	 * advertised capabilities.
2701 	 */
2702 	if (!system_capabilities_finalized())
2703 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
2704 	else
2705 		verify_local_cpu_capabilities();
2706 }
2707 
2708 static void __init setup_boot_cpu_capabilities(void)
2709 {
2710 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
2711 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
2712 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
2713 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
2714 }
2715 
2716 bool this_cpu_has_cap(unsigned int n)
2717 {
2718 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
2719 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2720 
2721 		if (cap)
2722 			return cap->matches(cap, SCOPE_LOCAL_CPU);
2723 	}
2724 
2725 	return false;
2726 }
2727 
2728 /*
2729  * This helper function is used in a narrow window when,
2730  * - The system wide safe registers are set with all the SMP CPUs and,
2731  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
2732  * In all other cases cpus_have_{const_}cap() should be used.
2733  */
2734 static bool __maybe_unused __system_matches_cap(unsigned int n)
2735 {
2736 	if (n < ARM64_NCAPS) {
2737 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2738 
2739 		if (cap)
2740 			return cap->matches(cap, SCOPE_SYSTEM);
2741 	}
2742 	return false;
2743 }
2744 
2745 void cpu_set_feature(unsigned int num)
2746 {
2747 	WARN_ON(num >= MAX_CPU_FEATURES);
2748 	elf_hwcap |= BIT(num);
2749 }
2750 EXPORT_SYMBOL_GPL(cpu_set_feature);
2751 
2752 bool cpu_have_feature(unsigned int num)
2753 {
2754 	WARN_ON(num >= MAX_CPU_FEATURES);
2755 	return elf_hwcap & BIT(num);
2756 }
2757 EXPORT_SYMBOL_GPL(cpu_have_feature);
2758 
2759 unsigned long cpu_get_elf_hwcap(void)
2760 {
2761 	/*
2762 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2763 	 * note that for userspace compatibility we guarantee that bits 62
2764 	 * and 63 will always be returned as 0.
2765 	 */
2766 	return lower_32_bits(elf_hwcap);
2767 }
2768 
2769 unsigned long cpu_get_elf_hwcap2(void)
2770 {
2771 	return upper_32_bits(elf_hwcap);
2772 }
2773 
2774 static void __init setup_system_capabilities(void)
2775 {
2776 	/*
2777 	 * We have finalised the system-wide safe feature
2778 	 * registers, finalise the capabilities that depend
2779 	 * on it. Also enable all the available capabilities,
2780 	 * that are not enabled already.
2781 	 */
2782 	update_cpu_capabilities(SCOPE_SYSTEM);
2783 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2784 }
2785 
2786 void __init setup_cpu_features(void)
2787 {
2788 	u32 cwg;
2789 
2790 	setup_system_capabilities();
2791 	setup_elf_hwcaps(arm64_elf_hwcaps);
2792 
2793 	if (system_supports_32bit_el0())
2794 		setup_elf_hwcaps(compat_elf_hwcaps);
2795 
2796 	if (system_uses_ttbr0_pan())
2797 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2798 
2799 	sve_setup();
2800 	minsigstksz_setup();
2801 
2802 	/* Advertise that we have computed the system capabilities */
2803 	finalize_system_capabilities();
2804 
2805 	/*
2806 	 * Check for sane CTR_EL0.CWG value.
2807 	 */
2808 	cwg = cache_type_cwg();
2809 	if (!cwg)
2810 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2811 			ARCH_DMA_MINALIGN);
2812 }
2813 
2814 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2815 {
2816 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2817 }
2818 
2819 /*
2820  * We emulate only the following system register space.
2821  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2822  * See Table C5-6 System instruction encodings for System register accesses,
2823  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2824  */
2825 static inline bool __attribute_const__ is_emulated(u32 id)
2826 {
2827 	return (sys_reg_Op0(id) == 0x3 &&
2828 		sys_reg_CRn(id) == 0x0 &&
2829 		sys_reg_Op1(id) == 0x0 &&
2830 		(sys_reg_CRm(id) == 0 ||
2831 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2832 }
2833 
2834 /*
2835  * With CRm == 0, reg should be one of :
2836  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2837  */
2838 static inline int emulate_id_reg(u32 id, u64 *valp)
2839 {
2840 	switch (id) {
2841 	case SYS_MIDR_EL1:
2842 		*valp = read_cpuid_id();
2843 		break;
2844 	case SYS_MPIDR_EL1:
2845 		*valp = SYS_MPIDR_SAFE_VAL;
2846 		break;
2847 	case SYS_REVIDR_EL1:
2848 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2849 		*valp = 0;
2850 		break;
2851 	default:
2852 		return -EINVAL;
2853 	}
2854 
2855 	return 0;
2856 }
2857 
2858 static int emulate_sys_reg(u32 id, u64 *valp)
2859 {
2860 	struct arm64_ftr_reg *regp;
2861 
2862 	if (!is_emulated(id))
2863 		return -EINVAL;
2864 
2865 	if (sys_reg_CRm(id) == 0)
2866 		return emulate_id_reg(id, valp);
2867 
2868 	regp = get_arm64_ftr_reg_nowarn(id);
2869 	if (regp)
2870 		*valp = arm64_ftr_reg_user_value(regp);
2871 	else
2872 		/*
2873 		 * The untracked registers are either IMPLEMENTATION DEFINED
2874 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2875 		 */
2876 		*valp = 0;
2877 	return 0;
2878 }
2879 
2880 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2881 {
2882 	int rc;
2883 	u64 val;
2884 
2885 	rc = emulate_sys_reg(sys_reg, &val);
2886 	if (!rc) {
2887 		pt_regs_write_reg(regs, rt, val);
2888 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2889 	}
2890 	return rc;
2891 }
2892 
2893 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2894 {
2895 	u32 sys_reg, rt;
2896 
2897 	/*
2898 	 * sys_reg values are defined as used in mrs/msr instruction.
2899 	 * shift the imm value to get the encoding.
2900 	 */
2901 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2902 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2903 	return do_emulate_mrs(regs, sys_reg, rt);
2904 }
2905 
2906 static struct undef_hook mrs_hook = {
2907 	.instr_mask = 0xfff00000,
2908 	.instr_val  = 0xd5300000,
2909 	.pstate_mask = PSR_AA32_MODE_MASK,
2910 	.pstate_val = PSR_MODE_EL0t,
2911 	.fn = emulate_mrs,
2912 };
2913 
2914 static int __init enable_mrs_emulation(void)
2915 {
2916 	register_undef_hook(&mrs_hook);
2917 	return 0;
2918 }
2919 
2920 core_initcall(enable_mrs_emulation);
2921 
2922 enum mitigation_state arm64_get_meltdown_state(void)
2923 {
2924 	if (__meltdown_safe)
2925 		return SPECTRE_UNAFFECTED;
2926 
2927 	if (arm64_kernel_unmapped_at_el0())
2928 		return SPECTRE_MITIGATED;
2929 
2930 	return SPECTRE_VULNERABLE;
2931 }
2932 
2933 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2934 			  char *buf)
2935 {
2936 	switch (arm64_get_meltdown_state()) {
2937 	case SPECTRE_UNAFFECTED:
2938 		return sprintf(buf, "Not affected\n");
2939 
2940 	case SPECTRE_MITIGATED:
2941 		return sprintf(buf, "Mitigation: PTI\n");
2942 
2943 	default:
2944 		return sprintf(buf, "Vulnerable\n");
2945 	}
2946 }
2947