xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision 7f6964c5)
1 /*
2  * Contains CPU feature definitions
3  *
4  * Copyright (C) 2015 ARM Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #define pr_fmt(fmt) "CPU features: " fmt
20 
21 #include <linux/bsearch.h>
22 #include <linux/cpumask.h>
23 #include <linux/crash_dump.h>
24 #include <linux/sort.h>
25 #include <linux/stop_machine.h>
26 #include <linux/types.h>
27 #include <linux/mm.h>
28 #include <linux/cpu.h>
29 #include <asm/cpu.h>
30 #include <asm/cpufeature.h>
31 #include <asm/cpu_ops.h>
32 #include <asm/fpsimd.h>
33 #include <asm/mmu_context.h>
34 #include <asm/processor.h>
35 #include <asm/sysreg.h>
36 #include <asm/traps.h>
37 #include <asm/virt.h>
38 
39 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
40 static unsigned long elf_hwcap __read_mostly;
41 
42 #ifdef CONFIG_COMPAT
43 #define COMPAT_ELF_HWCAP_DEFAULT	\
44 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
45 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
46 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
47 				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
48 				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
49 				 COMPAT_HWCAP_LPAE)
50 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
51 unsigned int compat_elf_hwcap2 __read_mostly;
52 #endif
53 
54 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
55 EXPORT_SYMBOL(cpu_hwcaps);
56 static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
57 
58 /* Need also bit for ARM64_CB_PATCH */
59 DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
60 
61 /*
62  * Flag to indicate if we have computed the system wide
63  * capabilities based on the boot time active CPUs. This
64  * will be used to determine if a new booting CPU should
65  * go through the verification process to make sure that it
66  * supports the system capabilities, without using a hotplug
67  * notifier.
68  */
69 static bool sys_caps_initialised;
70 
71 static inline void set_sys_caps_initialised(void)
72 {
73 	sys_caps_initialised = true;
74 }
75 
76 static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p)
77 {
78 	/* file-wide pr_fmt adds "CPU features: " prefix */
79 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
80 	return 0;
81 }
82 
83 static struct notifier_block cpu_hwcaps_notifier = {
84 	.notifier_call = dump_cpu_hwcaps
85 };
86 
87 static int __init register_cpu_hwcaps_dumper(void)
88 {
89 	atomic_notifier_chain_register(&panic_notifier_list,
90 				       &cpu_hwcaps_notifier);
91 	return 0;
92 }
93 __initcall(register_cpu_hwcaps_dumper);
94 
95 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
96 EXPORT_SYMBOL(cpu_hwcap_keys);
97 
98 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
99 	{						\
100 		.sign = SIGNED,				\
101 		.visible = VISIBLE,			\
102 		.strict = STRICT,			\
103 		.type = TYPE,				\
104 		.shift = SHIFT,				\
105 		.width = WIDTH,				\
106 		.safe_val = SAFE_VAL,			\
107 	}
108 
109 /* Define a feature with unsigned values */
110 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
111 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
112 
113 /* Define a feature with a signed value */
114 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
115 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
116 
117 #define ARM64_FTR_END					\
118 	{						\
119 		.width = 0,				\
120 	}
121 
122 /* meta feature for alternatives */
123 static bool __maybe_unused
124 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
125 
126 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
127 
128 /*
129  * NOTE: Any changes to the visibility of features should be kept in
130  * sync with the documentation of the CPU feature register ABI.
131  */
132 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
133 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
134 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
135 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
136 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
137 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
138 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
139 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
140 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
141 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
142 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
143 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
144 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
145 	ARM64_FTR_END,
146 };
147 
148 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
149 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
150 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
151 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
152 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
153 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
154 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
155 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
156 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
157 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
158 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_API_SHIFT, 4, 0),
159 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
160 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_APA_SHIFT, 4, 0),
161 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
162 	ARM64_FTR_END,
163 };
164 
165 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
166 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
167 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
168 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
169 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
170 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
171 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
172 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
173 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
174 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
175 	/* Linux doesn't care about the EL3 */
176 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
177 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
178 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
179 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
180 	ARM64_FTR_END,
181 };
182 
183 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
184 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
185 	ARM64_FTR_END,
186 };
187 
188 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
189 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
192 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
193 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
194 	ARM64_FTR_END,
195 };
196 
197 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
198 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
199 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
200 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
201 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
202 	/* Linux shouldn't care about secure memory */
203 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
204 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
205 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
206 	/*
207 	 * Differing PARange is fine as long as all peripherals and memory are mapped
208 	 * within the minimum PARange of all CPUs
209 	 */
210 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
211 	ARM64_FTR_END,
212 };
213 
214 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
215 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
217 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
218 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
219 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
220 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
221 	ARM64_FTR_END,
222 };
223 
224 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
225 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
226 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
227 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
228 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
230 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
231 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
232 	ARM64_FTR_END,
233 };
234 
235 static const struct arm64_ftr_bits ftr_ctr[] = {
236 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
237 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
238 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
239 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, CTR_CWG_SHIFT, 4, 0),
240 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, CTR_ERG_SHIFT, 4, 0),
241 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
242 	/*
243 	 * Linux can handle differing I-cache policies. Userspace JITs will
244 	 * make use of *minLine.
245 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
246 	 */
247 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
248 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
249 	ARM64_FTR_END,
250 };
251 
252 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
253 	.name		= "SYS_CTR_EL0",
254 	.ftr_bits	= ftr_ctr
255 };
256 
257 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
258 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0xf),	/* InnerShr */
259 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),	/* FCSE */
260 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),	/* AuxReg */
261 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),	/* TCM */
262 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),	/* ShareLvl */
263 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0xf),	/* OuterShr */
264 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),	/* PMSA */
265 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* VMSA */
266 	ARM64_FTR_END,
267 };
268 
269 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
270 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 36, 28, 0),
271 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
272 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
273 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
274 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
275 	/*
276 	 * We can instantiate multiple PMU instances with different levels
277 	 * of support.
278 	 */
279 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
280 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
281 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
282 	ARM64_FTR_END,
283 };
284 
285 static const struct arm64_ftr_bits ftr_mvfr2[] = {
286 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),		/* FPMisc */
287 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),		/* SIMDMisc */
288 	ARM64_FTR_END,
289 };
290 
291 static const struct arm64_ftr_bits ftr_dczid[] = {
292 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 4, 1, 1),		/* DZP */
293 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* BS */
294 	ARM64_FTR_END,
295 };
296 
297 
298 static const struct arm64_ftr_bits ftr_id_isar5[] = {
299 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
300 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
301 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
302 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
303 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
304 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
305 	ARM64_FTR_END,
306 };
307 
308 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
309 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),	/* ac2 */
310 	ARM64_FTR_END,
311 };
312 
313 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
314 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),		/* State3 */
315 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),		/* State2 */
316 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),		/* State1 */
317 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),		/* State0 */
318 	ARM64_FTR_END,
319 };
320 
321 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
322 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
323 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf),	/* PerfMon */
324 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
325 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
326 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
327 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
328 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
329 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
330 	ARM64_FTR_END,
331 };
332 
333 static const struct arm64_ftr_bits ftr_zcr[] = {
334 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
335 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
336 	ARM64_FTR_END,
337 };
338 
339 /*
340  * Common ftr bits for a 32bit register with all hidden, strict
341  * attributes, with 4bit feature fields and a default safe value of
342  * 0. Covers the following 32bit registers:
343  * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
344  */
345 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
346 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
347 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
348 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
349 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
350 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
351 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
352 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
353 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
354 	ARM64_FTR_END,
355 };
356 
357 /* Table for a single 32bit feature value */
358 static const struct arm64_ftr_bits ftr_single32[] = {
359 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
360 	ARM64_FTR_END,
361 };
362 
363 static const struct arm64_ftr_bits ftr_raz[] = {
364 	ARM64_FTR_END,
365 };
366 
367 #define ARM64_FTR_REG(id, table) {		\
368 	.sys_id = id,				\
369 	.reg = 	&(struct arm64_ftr_reg){	\
370 		.name = #id,			\
371 		.ftr_bits = &((table)[0]),	\
372 	}}
373 
374 static const struct __ftr_reg_entry {
375 	u32			sys_id;
376 	struct arm64_ftr_reg 	*reg;
377 } arm64_ftr_regs[] = {
378 
379 	/* Op1 = 0, CRn = 0, CRm = 1 */
380 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
381 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
382 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
383 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
384 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
385 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
386 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
387 
388 	/* Op1 = 0, CRn = 0, CRm = 2 */
389 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
390 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
391 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
392 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
393 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
394 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
395 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
396 
397 	/* Op1 = 0, CRn = 0, CRm = 3 */
398 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
399 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
400 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
401 
402 	/* Op1 = 0, CRn = 0, CRm = 4 */
403 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
404 	ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1),
405 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
406 
407 	/* Op1 = 0, CRn = 0, CRm = 5 */
408 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
409 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
410 
411 	/* Op1 = 0, CRn = 0, CRm = 6 */
412 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
413 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
414 
415 	/* Op1 = 0, CRn = 0, CRm = 7 */
416 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
417 	ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
418 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
419 
420 	/* Op1 = 0, CRn = 1, CRm = 2 */
421 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
422 
423 	/* Op1 = 3, CRn = 0, CRm = 0 */
424 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
425 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
426 
427 	/* Op1 = 3, CRn = 14, CRm = 0 */
428 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
429 };
430 
431 static int search_cmp_ftr_reg(const void *id, const void *regp)
432 {
433 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
434 }
435 
436 /*
437  * get_arm64_ftr_reg - Lookup a feature register entry using its
438  * sys_reg() encoding. With the array arm64_ftr_regs sorted in the
439  * ascending order of sys_id , we use binary search to find a matching
440  * entry.
441  *
442  * returns - Upon success,  matching ftr_reg entry for id.
443  *         - NULL on failure. It is upto the caller to decide
444  *	     the impact of a failure.
445  */
446 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
447 {
448 	const struct __ftr_reg_entry *ret;
449 
450 	ret = bsearch((const void *)(unsigned long)sys_id,
451 			arm64_ftr_regs,
452 			ARRAY_SIZE(arm64_ftr_regs),
453 			sizeof(arm64_ftr_regs[0]),
454 			search_cmp_ftr_reg);
455 	if (ret)
456 		return ret->reg;
457 	return NULL;
458 }
459 
460 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
461 			       s64 ftr_val)
462 {
463 	u64 mask = arm64_ftr_mask(ftrp);
464 
465 	reg &= ~mask;
466 	reg |= (ftr_val << ftrp->shift) & mask;
467 	return reg;
468 }
469 
470 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
471 				s64 cur)
472 {
473 	s64 ret = 0;
474 
475 	switch (ftrp->type) {
476 	case FTR_EXACT:
477 		ret = ftrp->safe_val;
478 		break;
479 	case FTR_LOWER_SAFE:
480 		ret = new < cur ? new : cur;
481 		break;
482 	case FTR_HIGHER_SAFE:
483 		ret = new > cur ? new : cur;
484 		break;
485 	default:
486 		BUG();
487 	}
488 
489 	return ret;
490 }
491 
492 static void __init sort_ftr_regs(void)
493 {
494 	int i;
495 
496 	/* Check that the array is sorted so that we can do the binary search */
497 	for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++)
498 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
499 }
500 
501 /*
502  * Initialise the CPU feature register from Boot CPU values.
503  * Also initiliases the strict_mask for the register.
504  * Any bits that are not covered by an arm64_ftr_bits entry are considered
505  * RES0 for the system-wide value, and must strictly match.
506  */
507 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
508 {
509 	u64 val = 0;
510 	u64 strict_mask = ~0x0ULL;
511 	u64 user_mask = 0;
512 	u64 valid_mask = 0;
513 
514 	const struct arm64_ftr_bits *ftrp;
515 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
516 
517 	BUG_ON(!reg);
518 
519 	for (ftrp  = reg->ftr_bits; ftrp->width; ftrp++) {
520 		u64 ftr_mask = arm64_ftr_mask(ftrp);
521 		s64 ftr_new = arm64_ftr_value(ftrp, new);
522 
523 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
524 
525 		valid_mask |= ftr_mask;
526 		if (!ftrp->strict)
527 			strict_mask &= ~ftr_mask;
528 		if (ftrp->visible)
529 			user_mask |= ftr_mask;
530 		else
531 			reg->user_val = arm64_ftr_set_value(ftrp,
532 							    reg->user_val,
533 							    ftrp->safe_val);
534 	}
535 
536 	val &= valid_mask;
537 
538 	reg->sys_val = val;
539 	reg->strict_mask = strict_mask;
540 	reg->user_mask = user_mask;
541 }
542 
543 extern const struct arm64_cpu_capabilities arm64_errata[];
544 static const struct arm64_cpu_capabilities arm64_features[];
545 
546 static void __init
547 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
548 {
549 	for (; caps->matches; caps++) {
550 		if (WARN(caps->capability >= ARM64_NCAPS,
551 			"Invalid capability %d\n", caps->capability))
552 			continue;
553 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
554 			"Duplicate entry for capability %d\n",
555 			caps->capability))
556 			continue;
557 		cpu_hwcaps_ptrs[caps->capability] = caps;
558 	}
559 }
560 
561 static void __init init_cpu_hwcaps_indirect_list(void)
562 {
563 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
564 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
565 }
566 
567 static void __init setup_boot_cpu_capabilities(void);
568 
569 void __init init_cpu_features(struct cpuinfo_arm64 *info)
570 {
571 	/* Before we start using the tables, make sure it is sorted */
572 	sort_ftr_regs();
573 
574 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
575 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
576 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
577 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
578 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
579 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
580 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
581 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
582 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
583 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
584 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
585 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
586 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
587 
588 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
589 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
590 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
591 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
592 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
593 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
594 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
595 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
596 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
597 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
598 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
599 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
600 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
601 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
602 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
603 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
604 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
605 	}
606 
607 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
608 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
609 		sve_init_vq_map();
610 	}
611 
612 	/*
613 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
614 	 * before we handle the boot CPU below.
615 	 */
616 	init_cpu_hwcaps_indirect_list();
617 
618 	/*
619 	 * Detect and enable early CPU capabilities based on the boot CPU,
620 	 * after we have initialised the CPU feature infrastructure.
621 	 */
622 	setup_boot_cpu_capabilities();
623 }
624 
625 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
626 {
627 	const struct arm64_ftr_bits *ftrp;
628 
629 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
630 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
631 		s64 ftr_new = arm64_ftr_value(ftrp, new);
632 
633 		if (ftr_cur == ftr_new)
634 			continue;
635 		/* Find a safe value */
636 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
637 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
638 	}
639 
640 }
641 
642 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
643 {
644 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
645 
646 	BUG_ON(!regp);
647 	update_cpu_ftr_reg(regp, val);
648 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
649 		return 0;
650 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
651 			regp->name, boot, cpu, val);
652 	return 1;
653 }
654 
655 /*
656  * Update system wide CPU feature registers with the values from a
657  * non-boot CPU. Also performs SANITY checks to make sure that there
658  * aren't any insane variations from that of the boot CPU.
659  */
660 void update_cpu_features(int cpu,
661 			 struct cpuinfo_arm64 *info,
662 			 struct cpuinfo_arm64 *boot)
663 {
664 	int taint = 0;
665 
666 	/*
667 	 * The kernel can handle differing I-cache policies, but otherwise
668 	 * caches should look identical. Userspace JITs will make use of
669 	 * *minLine.
670 	 */
671 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
672 				      info->reg_ctr, boot->reg_ctr);
673 
674 	/*
675 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
676 	 * could result in too much or too little memory being zeroed if a
677 	 * process is preempted and migrated between CPUs.
678 	 */
679 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
680 				      info->reg_dczid, boot->reg_dczid);
681 
682 	/* If different, timekeeping will be broken (especially with KVM) */
683 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
684 				      info->reg_cntfrq, boot->reg_cntfrq);
685 
686 	/*
687 	 * The kernel uses self-hosted debug features and expects CPUs to
688 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
689 	 * and BRPs to be identical.
690 	 * ID_AA64DFR1 is currently RES0.
691 	 */
692 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
693 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
694 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
695 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
696 	/*
697 	 * Even in big.LITTLE, processors should be identical instruction-set
698 	 * wise.
699 	 */
700 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
701 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
702 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
703 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
704 
705 	/*
706 	 * Differing PARange support is fine as long as all peripherals and
707 	 * memory are mapped within the minimum PARange of all CPUs.
708 	 * Linux should not care about secure memory.
709 	 */
710 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
711 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
712 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
713 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
714 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
715 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
716 
717 	/*
718 	 * EL3 is not our concern.
719 	 */
720 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
721 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
722 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
723 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
724 
725 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
726 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
727 
728 	/*
729 	 * If we have AArch32, we care about 32-bit features for compat.
730 	 * If the system doesn't support AArch32, don't update them.
731 	 */
732 	if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
733 		id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
734 
735 		taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
736 					info->reg_id_dfr0, boot->reg_id_dfr0);
737 		taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
738 					info->reg_id_isar0, boot->reg_id_isar0);
739 		taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
740 					info->reg_id_isar1, boot->reg_id_isar1);
741 		taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
742 					info->reg_id_isar2, boot->reg_id_isar2);
743 		taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
744 					info->reg_id_isar3, boot->reg_id_isar3);
745 		taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
746 					info->reg_id_isar4, boot->reg_id_isar4);
747 		taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
748 					info->reg_id_isar5, boot->reg_id_isar5);
749 
750 		/*
751 		 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
752 		 * ACTLR formats could differ across CPUs and therefore would have to
753 		 * be trapped for virtualization anyway.
754 		 */
755 		taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
756 					info->reg_id_mmfr0, boot->reg_id_mmfr0);
757 		taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
758 					info->reg_id_mmfr1, boot->reg_id_mmfr1);
759 		taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
760 					info->reg_id_mmfr2, boot->reg_id_mmfr2);
761 		taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
762 					info->reg_id_mmfr3, boot->reg_id_mmfr3);
763 		taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
764 					info->reg_id_pfr0, boot->reg_id_pfr0);
765 		taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
766 					info->reg_id_pfr1, boot->reg_id_pfr1);
767 		taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
768 					info->reg_mvfr0, boot->reg_mvfr0);
769 		taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
770 					info->reg_mvfr1, boot->reg_mvfr1);
771 		taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
772 					info->reg_mvfr2, boot->reg_mvfr2);
773 	}
774 
775 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
776 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
777 					info->reg_zcr, boot->reg_zcr);
778 
779 		/* Probe vector lengths, unless we already gave up on SVE */
780 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
781 		    !sys_caps_initialised)
782 			sve_update_vq_map();
783 	}
784 
785 	/*
786 	 * Mismatched CPU features are a recipe for disaster. Don't even
787 	 * pretend to support them.
788 	 */
789 	if (taint) {
790 		pr_warn_once("Unsupported CPU feature variation detected.\n");
791 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
792 	}
793 }
794 
795 u64 read_sanitised_ftr_reg(u32 id)
796 {
797 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
798 
799 	/* We shouldn't get a request for an unsupported register */
800 	BUG_ON(!regp);
801 	return regp->sys_val;
802 }
803 
804 #define read_sysreg_case(r)	\
805 	case r:		return read_sysreg_s(r)
806 
807 /*
808  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
809  * Read the system register on the current CPU
810  */
811 static u64 __read_sysreg_by_encoding(u32 sys_id)
812 {
813 	switch (sys_id) {
814 	read_sysreg_case(SYS_ID_PFR0_EL1);
815 	read_sysreg_case(SYS_ID_PFR1_EL1);
816 	read_sysreg_case(SYS_ID_DFR0_EL1);
817 	read_sysreg_case(SYS_ID_MMFR0_EL1);
818 	read_sysreg_case(SYS_ID_MMFR1_EL1);
819 	read_sysreg_case(SYS_ID_MMFR2_EL1);
820 	read_sysreg_case(SYS_ID_MMFR3_EL1);
821 	read_sysreg_case(SYS_ID_ISAR0_EL1);
822 	read_sysreg_case(SYS_ID_ISAR1_EL1);
823 	read_sysreg_case(SYS_ID_ISAR2_EL1);
824 	read_sysreg_case(SYS_ID_ISAR3_EL1);
825 	read_sysreg_case(SYS_ID_ISAR4_EL1);
826 	read_sysreg_case(SYS_ID_ISAR5_EL1);
827 	read_sysreg_case(SYS_MVFR0_EL1);
828 	read_sysreg_case(SYS_MVFR1_EL1);
829 	read_sysreg_case(SYS_MVFR2_EL1);
830 
831 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
832 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
833 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
834 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
835 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
836 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
837 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
838 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
839 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
840 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
841 
842 	read_sysreg_case(SYS_CNTFRQ_EL0);
843 	read_sysreg_case(SYS_CTR_EL0);
844 	read_sysreg_case(SYS_DCZID_EL0);
845 
846 	default:
847 		BUG();
848 		return 0;
849 	}
850 }
851 
852 #include <linux/irqchip/arm-gic-v3.h>
853 
854 static bool
855 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
856 {
857 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
858 
859 	return val >= entry->min_field_value;
860 }
861 
862 static bool
863 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
864 {
865 	u64 val;
866 
867 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
868 	if (scope == SCOPE_SYSTEM)
869 		val = read_sanitised_ftr_reg(entry->sys_reg);
870 	else
871 		val = __read_sysreg_by_encoding(entry->sys_reg);
872 
873 	return feature_matches(val, entry);
874 }
875 
876 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
877 {
878 	bool has_sre;
879 
880 	if (!has_cpuid_feature(entry, scope))
881 		return false;
882 
883 	has_sre = gic_enable_sre();
884 	if (!has_sre)
885 		pr_warn_once("%s present but disabled by higher exception level\n",
886 			     entry->desc);
887 
888 	return has_sre;
889 }
890 
891 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
892 {
893 	u32 midr = read_cpuid_id();
894 
895 	/* Cavium ThunderX pass 1.x and 2.x */
896 	return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
897 		MIDR_CPU_VAR_REV(0, 0),
898 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
899 }
900 
901 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
902 {
903 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
904 
905 	return cpuid_feature_extract_signed_field(pfr0,
906 					ID_AA64PFR0_FP_SHIFT) < 0;
907 }
908 
909 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
910 			  int scope)
911 {
912 	u64 ctr;
913 
914 	if (scope == SCOPE_SYSTEM)
915 		ctr = arm64_ftr_reg_ctrel0.sys_val;
916 	else
917 		ctr = read_cpuid_effective_cachetype();
918 
919 	return ctr & BIT(CTR_IDC_SHIFT);
920 }
921 
922 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
923 {
924 	/*
925 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
926 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
927 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
928 	 * value.
929 	 */
930 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
931 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
932 }
933 
934 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
935 			  int scope)
936 {
937 	u64 ctr;
938 
939 	if (scope == SCOPE_SYSTEM)
940 		ctr = arm64_ftr_reg_ctrel0.sys_val;
941 	else
942 		ctr = read_cpuid_cachetype();
943 
944 	return ctr & BIT(CTR_DIC_SHIFT);
945 }
946 
947 static bool __maybe_unused
948 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
949 {
950 	/*
951 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
952 	 * may share TLB entries with a CPU stuck in the crashed
953 	 * kernel.
954 	 */
955 	 if (is_kdump_kernel())
956 		return false;
957 
958 	return has_cpuid_feature(entry, scope);
959 }
960 
961 static bool __meltdown_safe = true;
962 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
963 
964 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
965 				int scope)
966 {
967 	/* List of CPUs that are not vulnerable and don't need KPTI */
968 	static const struct midr_range kpti_safe_list[] = {
969 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
970 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
971 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
972 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
973 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
974 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
975 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
976 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
977 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
978 		{ /* sentinel */ }
979 	};
980 	char const *str = "kpti command line option";
981 	bool meltdown_safe;
982 
983 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
984 
985 	/* Defer to CPU feature registers */
986 	if (has_cpuid_feature(entry, scope))
987 		meltdown_safe = true;
988 
989 	if (!meltdown_safe)
990 		__meltdown_safe = false;
991 
992 	/*
993 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
994 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
995 	 * ends as well as you might imagine. Don't even try.
996 	 */
997 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
998 		str = "ARM64_WORKAROUND_CAVIUM_27456";
999 		__kpti_forced = -1;
1000 	}
1001 
1002 	/* Useful for KASLR robustness */
1003 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) {
1004 		if (!__kpti_forced) {
1005 			str = "KASLR";
1006 			__kpti_forced = 1;
1007 		}
1008 	}
1009 
1010 	if (cpu_mitigations_off() && !__kpti_forced) {
1011 		str = "mitigations=off";
1012 		__kpti_forced = -1;
1013 	}
1014 
1015 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1016 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1017 		return false;
1018 	}
1019 
1020 	/* Forced? */
1021 	if (__kpti_forced) {
1022 		pr_info_once("kernel page table isolation forced %s by %s\n",
1023 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1024 		return __kpti_forced > 0;
1025 	}
1026 
1027 	return !meltdown_safe;
1028 }
1029 
1030 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1031 static void
1032 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1033 {
1034 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1035 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1036 	kpti_remap_fn *remap_fn;
1037 
1038 	static bool kpti_applied = false;
1039 	int cpu = smp_processor_id();
1040 
1041 	/*
1042 	 * We don't need to rewrite the page-tables if either we've done
1043 	 * it already or we have KASLR enabled and therefore have not
1044 	 * created any global mappings at all.
1045 	 */
1046 	if (kpti_applied || kaslr_offset() > 0)
1047 		return;
1048 
1049 	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
1050 
1051 	cpu_install_idmap();
1052 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1053 	cpu_uninstall_idmap();
1054 
1055 	if (!cpu)
1056 		kpti_applied = true;
1057 
1058 	return;
1059 }
1060 #else
1061 static void
1062 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1063 {
1064 }
1065 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1066 
1067 static int __init parse_kpti(char *str)
1068 {
1069 	bool enabled;
1070 	int ret = strtobool(str, &enabled);
1071 
1072 	if (ret)
1073 		return ret;
1074 
1075 	__kpti_forced = enabled ? 1 : -1;
1076 	return 0;
1077 }
1078 early_param("kpti", parse_kpti);
1079 
1080 #ifdef CONFIG_ARM64_HW_AFDBM
1081 static inline void __cpu_enable_hw_dbm(void)
1082 {
1083 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1084 
1085 	write_sysreg(tcr, tcr_el1);
1086 	isb();
1087 }
1088 
1089 static bool cpu_has_broken_dbm(void)
1090 {
1091 	/* List of CPUs which have broken DBM support. */
1092 	static const struct midr_range cpus[] = {
1093 #ifdef CONFIG_ARM64_ERRATUM_1024718
1094 		MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0),  // A55 r0p0 -r1p0
1095 #endif
1096 		{},
1097 	};
1098 
1099 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1100 }
1101 
1102 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1103 {
1104 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1105 	       !cpu_has_broken_dbm();
1106 }
1107 
1108 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1109 {
1110 	if (cpu_can_use_dbm(cap))
1111 		__cpu_enable_hw_dbm();
1112 }
1113 
1114 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1115 		       int __unused)
1116 {
1117 	static bool detected = false;
1118 	/*
1119 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1120 	 * run a mix of CPUs with and without the feature. So, we
1121 	 * unconditionally enable the capability to allow any late CPU
1122 	 * to use the feature. We only enable the control bits on the
1123 	 * CPU, if it actually supports.
1124 	 *
1125 	 * We have to make sure we print the "feature" detection only
1126 	 * when at least one CPU actually uses it. So check if this CPU
1127 	 * can actually use it and print the message exactly once.
1128 	 *
1129 	 * This is safe as all CPUs (including secondary CPUs - due to the
1130 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1131 	 * goes through the "matches" check exactly once. Also if a CPU
1132 	 * matches the criteria, it is guaranteed that the CPU will turn
1133 	 * the DBM on, as the capability is unconditionally enabled.
1134 	 */
1135 	if (!detected && cpu_can_use_dbm(cap)) {
1136 		detected = true;
1137 		pr_info("detected: Hardware dirty bit management\n");
1138 	}
1139 
1140 	return true;
1141 }
1142 
1143 #endif
1144 
1145 #ifdef CONFIG_ARM64_VHE
1146 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1147 {
1148 	return is_kernel_in_hyp_mode();
1149 }
1150 
1151 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1152 {
1153 	/*
1154 	 * Copy register values that aren't redirected by hardware.
1155 	 *
1156 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1157 	 * this value to tpidr_el2 before we patch the code. Once we've done
1158 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1159 	 * do anything here.
1160 	 */
1161 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1162 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1163 }
1164 #endif
1165 
1166 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1167 {
1168 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1169 
1170 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1171 	WARN_ON(val & (7 << 27 | 7 << 21));
1172 }
1173 
1174 #ifdef CONFIG_ARM64_SSBD
1175 static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
1176 {
1177 	if (user_mode(regs))
1178 		return 1;
1179 
1180 	if (instr & BIT(PSTATE_Imm_shift))
1181 		regs->pstate |= PSR_SSBS_BIT;
1182 	else
1183 		regs->pstate &= ~PSR_SSBS_BIT;
1184 
1185 	arm64_skip_faulting_instruction(regs, 4);
1186 	return 0;
1187 }
1188 
1189 static struct undef_hook ssbs_emulation_hook = {
1190 	.instr_mask	= ~(1U << PSTATE_Imm_shift),
1191 	.instr_val	= 0xd500401f | PSTATE_SSBS,
1192 	.fn		= ssbs_emulation_handler,
1193 };
1194 
1195 static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
1196 {
1197 	static bool undef_hook_registered = false;
1198 	static DEFINE_SPINLOCK(hook_lock);
1199 
1200 	spin_lock(&hook_lock);
1201 	if (!undef_hook_registered) {
1202 		register_undef_hook(&ssbs_emulation_hook);
1203 		undef_hook_registered = true;
1204 	}
1205 	spin_unlock(&hook_lock);
1206 
1207 	if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
1208 		sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
1209 		arm64_set_ssbd_mitigation(false);
1210 	} else {
1211 		arm64_set_ssbd_mitigation(true);
1212 	}
1213 }
1214 #endif /* CONFIG_ARM64_SSBD */
1215 
1216 #ifdef CONFIG_ARM64_PAN
1217 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1218 {
1219 	/*
1220 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1221 	 * is discarded once we return from the exception.
1222 	 */
1223 	WARN_ON_ONCE(in_interrupt());
1224 
1225 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1226 	asm(SET_PSTATE_PAN(1));
1227 }
1228 #endif /* CONFIG_ARM64_PAN */
1229 
1230 #ifdef CONFIG_ARM64_RAS_EXTN
1231 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1232 {
1233 	/* Firmware may have left a deferred SError in this register. */
1234 	write_sysreg_s(0, SYS_DISR_EL1);
1235 }
1236 #endif /* CONFIG_ARM64_RAS_EXTN */
1237 
1238 #ifdef CONFIG_ARM64_PTR_AUTH
1239 static void cpu_enable_address_auth(struct arm64_cpu_capabilities const *cap)
1240 {
1241 	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ENIA | SCTLR_ELx_ENIB |
1242 				       SCTLR_ELx_ENDA | SCTLR_ELx_ENDB);
1243 }
1244 #endif /* CONFIG_ARM64_PTR_AUTH */
1245 
1246 #ifdef CONFIG_ARM64_PSEUDO_NMI
1247 static bool enable_pseudo_nmi;
1248 
1249 static int __init early_enable_pseudo_nmi(char *p)
1250 {
1251 	return strtobool(p, &enable_pseudo_nmi);
1252 }
1253 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1254 
1255 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1256 				   int scope)
1257 {
1258 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1259 }
1260 #endif
1261 
1262 static const struct arm64_cpu_capabilities arm64_features[] = {
1263 	{
1264 		.desc = "GIC system register CPU interface",
1265 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1266 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1267 		.matches = has_useable_gicv3_cpuif,
1268 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1269 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1270 		.sign = FTR_UNSIGNED,
1271 		.min_field_value = 1,
1272 	},
1273 #ifdef CONFIG_ARM64_PAN
1274 	{
1275 		.desc = "Privileged Access Never",
1276 		.capability = ARM64_HAS_PAN,
1277 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1278 		.matches = has_cpuid_feature,
1279 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1280 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1281 		.sign = FTR_UNSIGNED,
1282 		.min_field_value = 1,
1283 		.cpu_enable = cpu_enable_pan,
1284 	},
1285 #endif /* CONFIG_ARM64_PAN */
1286 #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
1287 	{
1288 		.desc = "LSE atomic instructions",
1289 		.capability = ARM64_HAS_LSE_ATOMICS,
1290 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1291 		.matches = has_cpuid_feature,
1292 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1293 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1294 		.sign = FTR_UNSIGNED,
1295 		.min_field_value = 2,
1296 	},
1297 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
1298 	{
1299 		.desc = "Software prefetching using PRFM",
1300 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1301 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1302 		.matches = has_no_hw_prefetch,
1303 	},
1304 #ifdef CONFIG_ARM64_UAO
1305 	{
1306 		.desc = "User Access Override",
1307 		.capability = ARM64_HAS_UAO,
1308 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1309 		.matches = has_cpuid_feature,
1310 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1311 		.field_pos = ID_AA64MMFR2_UAO_SHIFT,
1312 		.min_field_value = 1,
1313 		/*
1314 		 * We rely on stop_machine() calling uao_thread_switch() to set
1315 		 * UAO immediately after patching.
1316 		 */
1317 	},
1318 #endif /* CONFIG_ARM64_UAO */
1319 #ifdef CONFIG_ARM64_PAN
1320 	{
1321 		.capability = ARM64_ALT_PAN_NOT_UAO,
1322 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1323 		.matches = cpufeature_pan_not_uao,
1324 	},
1325 #endif /* CONFIG_ARM64_PAN */
1326 #ifdef CONFIG_ARM64_VHE
1327 	{
1328 		.desc = "Virtualization Host Extensions",
1329 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1330 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1331 		.matches = runs_at_el2,
1332 		.cpu_enable = cpu_copy_el2regs,
1333 	},
1334 #endif	/* CONFIG_ARM64_VHE */
1335 	{
1336 		.desc = "32-bit EL0 Support",
1337 		.capability = ARM64_HAS_32BIT_EL0,
1338 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1339 		.matches = has_cpuid_feature,
1340 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1341 		.sign = FTR_UNSIGNED,
1342 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1343 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1344 	},
1345 	{
1346 		.desc = "Kernel page table isolation (KPTI)",
1347 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1348 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1349 		/*
1350 		 * The ID feature fields below are used to indicate that
1351 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1352 		 * more details.
1353 		 */
1354 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1355 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1356 		.min_field_value = 1,
1357 		.matches = unmap_kernel_at_el0,
1358 		.cpu_enable = kpti_install_ng_mappings,
1359 	},
1360 	{
1361 		/* FP/SIMD is not implemented */
1362 		.capability = ARM64_HAS_NO_FPSIMD,
1363 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1364 		.min_field_value = 0,
1365 		.matches = has_no_fpsimd,
1366 	},
1367 #ifdef CONFIG_ARM64_PMEM
1368 	{
1369 		.desc = "Data cache clean to Point of Persistence",
1370 		.capability = ARM64_HAS_DCPOP,
1371 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1372 		.matches = has_cpuid_feature,
1373 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1374 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1375 		.min_field_value = 1,
1376 	},
1377 	{
1378 		.desc = "Data cache clean to Point of Deep Persistence",
1379 		.capability = ARM64_HAS_DCPODP,
1380 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1381 		.matches = has_cpuid_feature,
1382 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1383 		.sign = FTR_UNSIGNED,
1384 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1385 		.min_field_value = 2,
1386 	},
1387 #endif
1388 #ifdef CONFIG_ARM64_SVE
1389 	{
1390 		.desc = "Scalable Vector Extension",
1391 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1392 		.capability = ARM64_SVE,
1393 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1394 		.sign = FTR_UNSIGNED,
1395 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1396 		.min_field_value = ID_AA64PFR0_SVE,
1397 		.matches = has_cpuid_feature,
1398 		.cpu_enable = sve_kernel_enable,
1399 	},
1400 #endif /* CONFIG_ARM64_SVE */
1401 #ifdef CONFIG_ARM64_RAS_EXTN
1402 	{
1403 		.desc = "RAS Extension Support",
1404 		.capability = ARM64_HAS_RAS_EXTN,
1405 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1406 		.matches = has_cpuid_feature,
1407 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1408 		.sign = FTR_UNSIGNED,
1409 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1410 		.min_field_value = ID_AA64PFR0_RAS_V1,
1411 		.cpu_enable = cpu_clear_disr,
1412 	},
1413 #endif /* CONFIG_ARM64_RAS_EXTN */
1414 	{
1415 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1416 		.capability = ARM64_HAS_CACHE_IDC,
1417 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1418 		.matches = has_cache_idc,
1419 		.cpu_enable = cpu_emulate_effective_ctr,
1420 	},
1421 	{
1422 		.desc = "Instruction cache invalidation not required for I/D coherence",
1423 		.capability = ARM64_HAS_CACHE_DIC,
1424 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1425 		.matches = has_cache_dic,
1426 	},
1427 	{
1428 		.desc = "Stage-2 Force Write-Back",
1429 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1430 		.capability = ARM64_HAS_STAGE2_FWB,
1431 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1432 		.sign = FTR_UNSIGNED,
1433 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
1434 		.min_field_value = 1,
1435 		.matches = has_cpuid_feature,
1436 		.cpu_enable = cpu_has_fwb,
1437 	},
1438 #ifdef CONFIG_ARM64_HW_AFDBM
1439 	{
1440 		/*
1441 		 * Since we turn this on always, we don't want the user to
1442 		 * think that the feature is available when it may not be.
1443 		 * So hide the description.
1444 		 *
1445 		 * .desc = "Hardware pagetable Dirty Bit Management",
1446 		 *
1447 		 */
1448 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1449 		.capability = ARM64_HW_DBM,
1450 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1451 		.sign = FTR_UNSIGNED,
1452 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
1453 		.min_field_value = 2,
1454 		.matches = has_hw_dbm,
1455 		.cpu_enable = cpu_enable_hw_dbm,
1456 	},
1457 #endif
1458 	{
1459 		.desc = "CRC32 instructions",
1460 		.capability = ARM64_HAS_CRC32,
1461 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1462 		.matches = has_cpuid_feature,
1463 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1464 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
1465 		.min_field_value = 1,
1466 	},
1467 #ifdef CONFIG_ARM64_SSBD
1468 	{
1469 		.desc = "Speculative Store Bypassing Safe (SSBS)",
1470 		.capability = ARM64_SSBS,
1471 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1472 		.matches = has_cpuid_feature,
1473 		.sys_reg = SYS_ID_AA64PFR1_EL1,
1474 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
1475 		.sign = FTR_UNSIGNED,
1476 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
1477 		.cpu_enable = cpu_enable_ssbs,
1478 	},
1479 #endif
1480 #ifdef CONFIG_ARM64_CNP
1481 	{
1482 		.desc = "Common not Private translations",
1483 		.capability = ARM64_HAS_CNP,
1484 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1485 		.matches = has_useable_cnp,
1486 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1487 		.sign = FTR_UNSIGNED,
1488 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
1489 		.min_field_value = 1,
1490 		.cpu_enable = cpu_enable_cnp,
1491 	},
1492 #endif
1493 	{
1494 		.desc = "Speculation barrier (SB)",
1495 		.capability = ARM64_HAS_SB,
1496 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1497 		.matches = has_cpuid_feature,
1498 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1499 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
1500 		.sign = FTR_UNSIGNED,
1501 		.min_field_value = 1,
1502 	},
1503 #ifdef CONFIG_ARM64_PTR_AUTH
1504 	{
1505 		.desc = "Address authentication (architected algorithm)",
1506 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
1507 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1508 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1509 		.sign = FTR_UNSIGNED,
1510 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
1511 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
1512 		.matches = has_cpuid_feature,
1513 		.cpu_enable = cpu_enable_address_auth,
1514 	},
1515 	{
1516 		.desc = "Address authentication (IMP DEF algorithm)",
1517 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
1518 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1519 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1520 		.sign = FTR_UNSIGNED,
1521 		.field_pos = ID_AA64ISAR1_API_SHIFT,
1522 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
1523 		.matches = has_cpuid_feature,
1524 		.cpu_enable = cpu_enable_address_auth,
1525 	},
1526 	{
1527 		.desc = "Generic authentication (architected algorithm)",
1528 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
1529 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1530 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1531 		.sign = FTR_UNSIGNED,
1532 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
1533 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
1534 		.matches = has_cpuid_feature,
1535 	},
1536 	{
1537 		.desc = "Generic authentication (IMP DEF algorithm)",
1538 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
1539 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1540 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1541 		.sign = FTR_UNSIGNED,
1542 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
1543 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
1544 		.matches = has_cpuid_feature,
1545 	},
1546 #endif /* CONFIG_ARM64_PTR_AUTH */
1547 #ifdef CONFIG_ARM64_PSEUDO_NMI
1548 	{
1549 		/*
1550 		 * Depends on having GICv3
1551 		 */
1552 		.desc = "IRQ priority masking",
1553 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
1554 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1555 		.matches = can_use_gic_priorities,
1556 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1557 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1558 		.sign = FTR_UNSIGNED,
1559 		.min_field_value = 1,
1560 	},
1561 #endif
1562 	{},
1563 };
1564 
1565 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
1566 		.matches = has_cpuid_feature,					\
1567 		.sys_reg = reg,							\
1568 		.field_pos = field,						\
1569 		.sign = s,							\
1570 		.min_field_value = min_value,
1571 
1572 #define __HWCAP_CAP(name, cap_type, cap)					\
1573 		.desc = name,							\
1574 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
1575 		.hwcap_type = cap_type,						\
1576 		.hwcap = cap,							\
1577 
1578 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
1579 	{									\
1580 		__HWCAP_CAP(#cap, cap_type, cap)				\
1581 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
1582 	}
1583 
1584 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
1585 	{									\
1586 		__HWCAP_CAP(#cap, cap_type, cap)				\
1587 		.matches = cpucap_multi_entry_cap_matches,			\
1588 		.match_list = list,						\
1589 	}
1590 
1591 #ifdef CONFIG_ARM64_PTR_AUTH
1592 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
1593 	{
1594 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
1595 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
1596 	},
1597 	{
1598 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
1599 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
1600 	},
1601 	{},
1602 };
1603 
1604 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
1605 	{
1606 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
1607 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
1608 	},
1609 	{
1610 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
1611 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
1612 	},
1613 	{},
1614 };
1615 #endif
1616 
1617 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
1618 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
1619 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
1620 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
1621 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
1622 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
1623 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
1624 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
1625 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
1626 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
1627 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
1628 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
1629 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
1630 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
1631 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
1632 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
1633 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
1634 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
1635 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
1636 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
1637 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
1638 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
1639 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
1640 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
1641 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
1642 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
1643 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
1644 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
1645 #ifdef CONFIG_ARM64_SVE
1646 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
1647 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
1648 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
1649 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
1650 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
1651 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
1652 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
1653 #endif
1654 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
1655 #ifdef CONFIG_ARM64_PTR_AUTH
1656 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
1657 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
1658 #endif
1659 	{},
1660 };
1661 
1662 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
1663 #ifdef CONFIG_COMPAT
1664 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
1665 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
1666 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
1667 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
1668 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
1669 #endif
1670 	{},
1671 };
1672 
1673 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
1674 {
1675 	switch (cap->hwcap_type) {
1676 	case CAP_HWCAP:
1677 		cpu_set_feature(cap->hwcap);
1678 		break;
1679 #ifdef CONFIG_COMPAT
1680 	case CAP_COMPAT_HWCAP:
1681 		compat_elf_hwcap |= (u32)cap->hwcap;
1682 		break;
1683 	case CAP_COMPAT_HWCAP2:
1684 		compat_elf_hwcap2 |= (u32)cap->hwcap;
1685 		break;
1686 #endif
1687 	default:
1688 		WARN_ON(1);
1689 		break;
1690 	}
1691 }
1692 
1693 /* Check if we have a particular HWCAP enabled */
1694 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
1695 {
1696 	bool rc;
1697 
1698 	switch (cap->hwcap_type) {
1699 	case CAP_HWCAP:
1700 		rc = cpu_have_feature(cap->hwcap);
1701 		break;
1702 #ifdef CONFIG_COMPAT
1703 	case CAP_COMPAT_HWCAP:
1704 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
1705 		break;
1706 	case CAP_COMPAT_HWCAP2:
1707 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
1708 		break;
1709 #endif
1710 	default:
1711 		WARN_ON(1);
1712 		rc = false;
1713 	}
1714 
1715 	return rc;
1716 }
1717 
1718 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
1719 {
1720 	/* We support emulation of accesses to CPU ID feature registers */
1721 	cpu_set_named_feature(CPUID);
1722 	for (; hwcaps->matches; hwcaps++)
1723 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
1724 			cap_set_elf_hwcap(hwcaps);
1725 }
1726 
1727 static void update_cpu_capabilities(u16 scope_mask)
1728 {
1729 	int i;
1730 	const struct arm64_cpu_capabilities *caps;
1731 
1732 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
1733 	for (i = 0; i < ARM64_NCAPS; i++) {
1734 		caps = cpu_hwcaps_ptrs[i];
1735 		if (!caps || !(caps->type & scope_mask) ||
1736 		    cpus_have_cap(caps->capability) ||
1737 		    !caps->matches(caps, cpucap_default_scope(caps)))
1738 			continue;
1739 
1740 		if (caps->desc)
1741 			pr_info("detected: %s\n", caps->desc);
1742 		cpus_set_cap(caps->capability);
1743 
1744 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
1745 			set_bit(caps->capability, boot_capabilities);
1746 	}
1747 }
1748 
1749 /*
1750  * Enable all the available capabilities on this CPU. The capabilities
1751  * with BOOT_CPU scope are handled separately and hence skipped here.
1752  */
1753 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
1754 {
1755 	int i;
1756 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
1757 
1758 	for_each_available_cap(i) {
1759 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
1760 
1761 		if (WARN_ON(!cap))
1762 			continue;
1763 
1764 		if (!(cap->type & non_boot_scope))
1765 			continue;
1766 
1767 		if (cap->cpu_enable)
1768 			cap->cpu_enable(cap);
1769 	}
1770 	return 0;
1771 }
1772 
1773 /*
1774  * Run through the enabled capabilities and enable() it on all active
1775  * CPUs
1776  */
1777 static void __init enable_cpu_capabilities(u16 scope_mask)
1778 {
1779 	int i;
1780 	const struct arm64_cpu_capabilities *caps;
1781 	bool boot_scope;
1782 
1783 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
1784 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
1785 
1786 	for (i = 0; i < ARM64_NCAPS; i++) {
1787 		unsigned int num;
1788 
1789 		caps = cpu_hwcaps_ptrs[i];
1790 		if (!caps || !(caps->type & scope_mask))
1791 			continue;
1792 		num = caps->capability;
1793 		if (!cpus_have_cap(num))
1794 			continue;
1795 
1796 		/* Ensure cpus_have_const_cap(num) works */
1797 		static_branch_enable(&cpu_hwcap_keys[num]);
1798 
1799 		if (boot_scope && caps->cpu_enable)
1800 			/*
1801 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
1802 			 * before any secondary CPU boots. Thus, each secondary
1803 			 * will enable the capability as appropriate via
1804 			 * check_local_cpu_capabilities(). The only exception is
1805 			 * the boot CPU, for which the capability must be
1806 			 * enabled here. This approach avoids costly
1807 			 * stop_machine() calls for this case.
1808 			 */
1809 			caps->cpu_enable(caps);
1810 	}
1811 
1812 	/*
1813 	 * For all non-boot scope capabilities, use stop_machine()
1814 	 * as it schedules the work allowing us to modify PSTATE,
1815 	 * instead of on_each_cpu() which uses an IPI, giving us a
1816 	 * PSTATE that disappears when we return.
1817 	 */
1818 	if (!boot_scope)
1819 		stop_machine(cpu_enable_non_boot_scope_capabilities,
1820 			     NULL, cpu_online_mask);
1821 }
1822 
1823 /*
1824  * Run through the list of capabilities to check for conflicts.
1825  * If the system has already detected a capability, take necessary
1826  * action on this CPU.
1827  *
1828  * Returns "false" on conflicts.
1829  */
1830 static bool verify_local_cpu_caps(u16 scope_mask)
1831 {
1832 	int i;
1833 	bool cpu_has_cap, system_has_cap;
1834 	const struct arm64_cpu_capabilities *caps;
1835 
1836 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
1837 
1838 	for (i = 0; i < ARM64_NCAPS; i++) {
1839 		caps = cpu_hwcaps_ptrs[i];
1840 		if (!caps || !(caps->type & scope_mask))
1841 			continue;
1842 
1843 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
1844 		system_has_cap = cpus_have_cap(caps->capability);
1845 
1846 		if (system_has_cap) {
1847 			/*
1848 			 * Check if the new CPU misses an advertised feature,
1849 			 * which is not safe to miss.
1850 			 */
1851 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
1852 				break;
1853 			/*
1854 			 * We have to issue cpu_enable() irrespective of
1855 			 * whether the CPU has it or not, as it is enabeld
1856 			 * system wide. It is upto the call back to take
1857 			 * appropriate action on this CPU.
1858 			 */
1859 			if (caps->cpu_enable)
1860 				caps->cpu_enable(caps);
1861 		} else {
1862 			/*
1863 			 * Check if the CPU has this capability if it isn't
1864 			 * safe to have when the system doesn't.
1865 			 */
1866 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
1867 				break;
1868 		}
1869 	}
1870 
1871 	if (i < ARM64_NCAPS) {
1872 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
1873 			smp_processor_id(), caps->capability,
1874 			caps->desc, system_has_cap, cpu_has_cap);
1875 		return false;
1876 	}
1877 
1878 	return true;
1879 }
1880 
1881 /*
1882  * Check for CPU features that are used in early boot
1883  * based on the Boot CPU value.
1884  */
1885 static void check_early_cpu_features(void)
1886 {
1887 	verify_cpu_asid_bits();
1888 	/*
1889 	 * Early features are used by the kernel already. If there
1890 	 * is a conflict, we cannot proceed further.
1891 	 */
1892 	if (!verify_local_cpu_caps(SCOPE_BOOT_CPU))
1893 		cpu_panic_kernel();
1894 }
1895 
1896 static void
1897 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
1898 {
1899 
1900 	for (; caps->matches; caps++)
1901 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
1902 			pr_crit("CPU%d: missing HWCAP: %s\n",
1903 					smp_processor_id(), caps->desc);
1904 			cpu_die_early();
1905 		}
1906 }
1907 
1908 static void verify_sve_features(void)
1909 {
1910 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
1911 	u64 zcr = read_zcr_features();
1912 
1913 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
1914 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
1915 
1916 	if (len < safe_len || sve_verify_vq_map()) {
1917 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
1918 			smp_processor_id());
1919 		cpu_die_early();
1920 	}
1921 
1922 	/* Add checks on other ZCR bits here if necessary */
1923 }
1924 
1925 
1926 /*
1927  * Run through the enabled system capabilities and enable() it on this CPU.
1928  * The capabilities were decided based on the available CPUs at the boot time.
1929  * Any new CPU should match the system wide status of the capability. If the
1930  * new CPU doesn't have a capability which the system now has enabled, we
1931  * cannot do anything to fix it up and could cause unexpected failures. So
1932  * we park the CPU.
1933  */
1934 static void verify_local_cpu_capabilities(void)
1935 {
1936 	/*
1937 	 * The capabilities with SCOPE_BOOT_CPU are checked from
1938 	 * check_early_cpu_features(), as they need to be verified
1939 	 * on all secondary CPUs.
1940 	 */
1941 	if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU))
1942 		cpu_die_early();
1943 
1944 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
1945 
1946 	if (system_supports_32bit_el0())
1947 		verify_local_elf_hwcaps(compat_elf_hwcaps);
1948 
1949 	if (system_supports_sve())
1950 		verify_sve_features();
1951 }
1952 
1953 void check_local_cpu_capabilities(void)
1954 {
1955 	/*
1956 	 * All secondary CPUs should conform to the early CPU features
1957 	 * in use by the kernel based on boot CPU.
1958 	 */
1959 	check_early_cpu_features();
1960 
1961 	/*
1962 	 * If we haven't finalised the system capabilities, this CPU gets
1963 	 * a chance to update the errata work arounds and local features.
1964 	 * Otherwise, this CPU should verify that it has all the system
1965 	 * advertised capabilities.
1966 	 */
1967 	if (!sys_caps_initialised)
1968 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
1969 	else
1970 		verify_local_cpu_capabilities();
1971 }
1972 
1973 static void __init setup_boot_cpu_capabilities(void)
1974 {
1975 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
1976 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
1977 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
1978 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
1979 }
1980 
1981 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
1982 EXPORT_SYMBOL(arm64_const_caps_ready);
1983 
1984 static void __init mark_const_caps_ready(void)
1985 {
1986 	static_branch_enable(&arm64_const_caps_ready);
1987 }
1988 
1989 bool this_cpu_has_cap(unsigned int n)
1990 {
1991 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
1992 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
1993 
1994 		if (cap)
1995 			return cap->matches(cap, SCOPE_LOCAL_CPU);
1996 	}
1997 
1998 	return false;
1999 }
2000 
2001 void cpu_set_feature(unsigned int num)
2002 {
2003 	WARN_ON(num >= MAX_CPU_FEATURES);
2004 	elf_hwcap |= BIT(num);
2005 }
2006 EXPORT_SYMBOL_GPL(cpu_set_feature);
2007 
2008 bool cpu_have_feature(unsigned int num)
2009 {
2010 	WARN_ON(num >= MAX_CPU_FEATURES);
2011 	return elf_hwcap & BIT(num);
2012 }
2013 EXPORT_SYMBOL_GPL(cpu_have_feature);
2014 
2015 unsigned long cpu_get_elf_hwcap(void)
2016 {
2017 	/*
2018 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2019 	 * note that for userspace compatibility we guarantee that bits 62
2020 	 * and 63 will always be returned as 0.
2021 	 */
2022 	return lower_32_bits(elf_hwcap);
2023 }
2024 
2025 unsigned long cpu_get_elf_hwcap2(void)
2026 {
2027 	return upper_32_bits(elf_hwcap);
2028 }
2029 
2030 static void __init setup_system_capabilities(void)
2031 {
2032 	/*
2033 	 * We have finalised the system-wide safe feature
2034 	 * registers, finalise the capabilities that depend
2035 	 * on it. Also enable all the available capabilities,
2036 	 * that are not enabled already.
2037 	 */
2038 	update_cpu_capabilities(SCOPE_SYSTEM);
2039 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2040 }
2041 
2042 void __init setup_cpu_features(void)
2043 {
2044 	u32 cwg;
2045 
2046 	setup_system_capabilities();
2047 	mark_const_caps_ready();
2048 	setup_elf_hwcaps(arm64_elf_hwcaps);
2049 
2050 	if (system_supports_32bit_el0())
2051 		setup_elf_hwcaps(compat_elf_hwcaps);
2052 
2053 	if (system_uses_ttbr0_pan())
2054 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2055 
2056 	sve_setup();
2057 	minsigstksz_setup();
2058 
2059 	/* Advertise that we have computed the system capabilities */
2060 	set_sys_caps_initialised();
2061 
2062 	/*
2063 	 * Check for sane CTR_EL0.CWG value.
2064 	 */
2065 	cwg = cache_type_cwg();
2066 	if (!cwg)
2067 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2068 			ARCH_DMA_MINALIGN);
2069 }
2070 
2071 static bool __maybe_unused
2072 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
2073 {
2074 	return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO));
2075 }
2076 
2077 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2078 {
2079 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2080 }
2081 
2082 /*
2083  * We emulate only the following system register space.
2084  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2085  * See Table C5-6 System instruction encodings for System register accesses,
2086  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2087  */
2088 static inline bool __attribute_const__ is_emulated(u32 id)
2089 {
2090 	return (sys_reg_Op0(id) == 0x3 &&
2091 		sys_reg_CRn(id) == 0x0 &&
2092 		sys_reg_Op1(id) == 0x0 &&
2093 		(sys_reg_CRm(id) == 0 ||
2094 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2095 }
2096 
2097 /*
2098  * With CRm == 0, reg should be one of :
2099  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2100  */
2101 static inline int emulate_id_reg(u32 id, u64 *valp)
2102 {
2103 	switch (id) {
2104 	case SYS_MIDR_EL1:
2105 		*valp = read_cpuid_id();
2106 		break;
2107 	case SYS_MPIDR_EL1:
2108 		*valp = SYS_MPIDR_SAFE_VAL;
2109 		break;
2110 	case SYS_REVIDR_EL1:
2111 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2112 		*valp = 0;
2113 		break;
2114 	default:
2115 		return -EINVAL;
2116 	}
2117 
2118 	return 0;
2119 }
2120 
2121 static int emulate_sys_reg(u32 id, u64 *valp)
2122 {
2123 	struct arm64_ftr_reg *regp;
2124 
2125 	if (!is_emulated(id))
2126 		return -EINVAL;
2127 
2128 	if (sys_reg_CRm(id) == 0)
2129 		return emulate_id_reg(id, valp);
2130 
2131 	regp = get_arm64_ftr_reg(id);
2132 	if (regp)
2133 		*valp = arm64_ftr_reg_user_value(regp);
2134 	else
2135 		/*
2136 		 * The untracked registers are either IMPLEMENTATION DEFINED
2137 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2138 		 */
2139 		*valp = 0;
2140 	return 0;
2141 }
2142 
2143 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2144 {
2145 	int rc;
2146 	u64 val;
2147 
2148 	rc = emulate_sys_reg(sys_reg, &val);
2149 	if (!rc) {
2150 		pt_regs_write_reg(regs, rt, val);
2151 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2152 	}
2153 	return rc;
2154 }
2155 
2156 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2157 {
2158 	u32 sys_reg, rt;
2159 
2160 	/*
2161 	 * sys_reg values are defined as used in mrs/msr instruction.
2162 	 * shift the imm value to get the encoding.
2163 	 */
2164 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2165 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2166 	return do_emulate_mrs(regs, sys_reg, rt);
2167 }
2168 
2169 static struct undef_hook mrs_hook = {
2170 	.instr_mask = 0xfff00000,
2171 	.instr_val  = 0xd5300000,
2172 	.pstate_mask = PSR_AA32_MODE_MASK,
2173 	.pstate_val = PSR_MODE_EL0t,
2174 	.fn = emulate_mrs,
2175 };
2176 
2177 static int __init enable_mrs_emulation(void)
2178 {
2179 	register_undef_hook(&mrs_hook);
2180 	return 0;
2181 }
2182 
2183 core_initcall(enable_mrs_emulation);
2184 
2185 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2186 			  char *buf)
2187 {
2188 	if (__meltdown_safe)
2189 		return sprintf(buf, "Not affected\n");
2190 
2191 	if (arm64_kernel_unmapped_at_el0())
2192 		return sprintf(buf, "Mitigation: PTI\n");
2193 
2194 	return sprintf(buf, "Vulnerable\n");
2195 }
2196