xref: /linux/arch/arm64/kernel/cpufeature.c (revision 842ed298954db7dc41a4942f3331d19cd9676ede)
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 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
356 	.name		= "SYS_CTR_EL0",
357 	.ftr_bits	= ftr_ctr
358 };
359 
360 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
361 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_INNERSHR_SHIFT, 4, 0xf),
362 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_FCSE_SHIFT, 4, 0),
363 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_AUXREG_SHIFT, 4, 0),
364 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_TCM_SHIFT, 4, 0),
365 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_SHARELVL_SHIFT, 4, 0),
366 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_OUTERSHR_SHIFT, 4, 0xf),
367 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_PMSA_SHIFT, 4, 0),
368 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_VMSA_SHIFT, 4, 0),
369 	ARM64_FTR_END,
370 };
371 
372 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
373 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_DOUBLELOCK_SHIFT, 4, 0),
374 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
375 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
376 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
377 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
378 	/*
379 	 * We can instantiate multiple PMU instances with different levels
380 	 * of support.
381 	 */
382 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
383 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
384 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
385 	ARM64_FTR_END,
386 };
387 
388 static const struct arm64_ftr_bits ftr_mvfr2[] = {
389 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_FPMISC_SHIFT, 4, 0),
390 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_SIMDMISC_SHIFT, 4, 0),
391 	ARM64_FTR_END,
392 };
393 
394 static const struct arm64_ftr_bits ftr_dczid[] = {
395 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_DZP_SHIFT, 1, 1),
396 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_BS_SHIFT, 4, 0),
397 	ARM64_FTR_END,
398 };
399 
400 static const struct arm64_ftr_bits ftr_id_isar0[] = {
401 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
402 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
403 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
404 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
405 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
406 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
407 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
408 	ARM64_FTR_END,
409 };
410 
411 static const struct arm64_ftr_bits ftr_id_isar5[] = {
412 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
413 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
414 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
415 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
416 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
417 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
418 	ARM64_FTR_END,
419 };
420 
421 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
422 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
423 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
424 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
427 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
428 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_AC2_SHIFT, 4, 0),
429 
430 	/*
431 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
432 	 * external abort on speculative read. It is safe to assume that an
433 	 * SError might be generated than it will not be. Hence it has been
434 	 * classified as FTR_HIGHER_SAFE.
435 	 */
436 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
437 	ARM64_FTR_END,
438 };
439 
440 static const struct arm64_ftr_bits ftr_id_isar4[] = {
441 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
442 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
443 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
444 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
446 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
447 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
448 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
449 	ARM64_FTR_END,
450 };
451 
452 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
453 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
454 	ARM64_FTR_END,
455 };
456 
457 static const struct arm64_ftr_bits ftr_id_isar6[] = {
458 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
459 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
460 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
463 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
464 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
465 	ARM64_FTR_END,
466 };
467 
468 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
469 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
470 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
471 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE3_SHIFT, 4, 0),
472 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE2_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE1_SHIFT, 4, 0),
474 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE0_SHIFT, 4, 0),
475 	ARM64_FTR_END,
476 };
477 
478 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
479 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
480 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
481 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
484 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
485 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
486 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
487 	ARM64_FTR_END,
488 };
489 
490 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
491 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
492 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
493 	ARM64_FTR_END,
494 };
495 
496 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
497 	/* [31:28] TraceFilt */
498 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_PERFMON_SHIFT, 4, 0xf),
499 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MPROFDBG_SHIFT, 4, 0),
500 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPTRC_SHIFT, 4, 0),
501 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPTRC_SHIFT, 4, 0),
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPDBG_SHIFT, 4, 0),
503 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPSDBG_SHIFT, 4, 0),
504 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPDBG_SHIFT, 4, 0),
505 	ARM64_FTR_END,
506 };
507 
508 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
509 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
510 	ARM64_FTR_END,
511 };
512 
513 static const struct arm64_ftr_bits ftr_zcr[] = {
514 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
515 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
516 	ARM64_FTR_END,
517 };
518 
519 /*
520  * Common ftr bits for a 32bit register with all hidden, strict
521  * attributes, with 4bit feature fields and a default safe value of
522  * 0. Covers the following 32bit registers:
523  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
524  */
525 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
526 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
527 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
531 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
532 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
533 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
534 	ARM64_FTR_END,
535 };
536 
537 /* Table for a single 32bit feature value */
538 static const struct arm64_ftr_bits ftr_single32[] = {
539 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
540 	ARM64_FTR_END,
541 };
542 
543 static const struct arm64_ftr_bits ftr_raz[] = {
544 	ARM64_FTR_END,
545 };
546 
547 #define ARM64_FTR_REG(id, table) {		\
548 	.sys_id = id,				\
549 	.reg = 	&(struct arm64_ftr_reg){	\
550 		.name = #id,			\
551 		.ftr_bits = &((table)[0]),	\
552 	}}
553 
554 static const struct __ftr_reg_entry {
555 	u32			sys_id;
556 	struct arm64_ftr_reg 	*reg;
557 } arm64_ftr_regs[] = {
558 
559 	/* Op1 = 0, CRn = 0, CRm = 1 */
560 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
561 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
562 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
563 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
564 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
565 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
566 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
567 
568 	/* Op1 = 0, CRn = 0, CRm = 2 */
569 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
570 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
571 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
572 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
573 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
574 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
575 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
576 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
577 
578 	/* Op1 = 0, CRn = 0, CRm = 3 */
579 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
580 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
581 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
582 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
583 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
584 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
585 
586 	/* Op1 = 0, CRn = 0, CRm = 4 */
587 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
588 	ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1),
589 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
590 
591 	/* Op1 = 0, CRn = 0, CRm = 5 */
592 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
593 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
594 
595 	/* Op1 = 0, CRn = 0, CRm = 6 */
596 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
597 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
598 
599 	/* Op1 = 0, CRn = 0, CRm = 7 */
600 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
601 	ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
602 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
603 
604 	/* Op1 = 0, CRn = 1, CRm = 2 */
605 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
606 
607 	/* Op1 = 3, CRn = 0, CRm = 0 */
608 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
609 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
610 
611 	/* Op1 = 3, CRn = 14, CRm = 0 */
612 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
613 };
614 
615 static int search_cmp_ftr_reg(const void *id, const void *regp)
616 {
617 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
618 }
619 
620 /*
621  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
622  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
623  * ascending order of sys_id, we use binary search to find a matching
624  * entry.
625  *
626  * returns - Upon success,  matching ftr_reg entry for id.
627  *         - NULL on failure. It is upto the caller to decide
628  *	     the impact of a failure.
629  */
630 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
631 {
632 	const struct __ftr_reg_entry *ret;
633 
634 	ret = bsearch((const void *)(unsigned long)sys_id,
635 			arm64_ftr_regs,
636 			ARRAY_SIZE(arm64_ftr_regs),
637 			sizeof(arm64_ftr_regs[0]),
638 			search_cmp_ftr_reg);
639 	if (ret)
640 		return ret->reg;
641 	return NULL;
642 }
643 
644 /*
645  * get_arm64_ftr_reg - Looks up a feature register entry using
646  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
647  *
648  * returns - Upon success,  matching ftr_reg entry for id.
649  *         - NULL on failure but with an WARN_ON().
650  */
651 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
652 {
653 	struct arm64_ftr_reg *reg;
654 
655 	reg = get_arm64_ftr_reg_nowarn(sys_id);
656 
657 	/*
658 	 * Requesting a non-existent register search is an error. Warn
659 	 * and let the caller handle it.
660 	 */
661 	WARN_ON(!reg);
662 	return reg;
663 }
664 
665 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
666 			       s64 ftr_val)
667 {
668 	u64 mask = arm64_ftr_mask(ftrp);
669 
670 	reg &= ~mask;
671 	reg |= (ftr_val << ftrp->shift) & mask;
672 	return reg;
673 }
674 
675 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
676 				s64 cur)
677 {
678 	s64 ret = 0;
679 
680 	switch (ftrp->type) {
681 	case FTR_EXACT:
682 		ret = ftrp->safe_val;
683 		break;
684 	case FTR_LOWER_SAFE:
685 		ret = new < cur ? new : cur;
686 		break;
687 	case FTR_HIGHER_OR_ZERO_SAFE:
688 		if (!cur || !new)
689 			break;
690 		fallthrough;
691 	case FTR_HIGHER_SAFE:
692 		ret = new > cur ? new : cur;
693 		break;
694 	default:
695 		BUG();
696 	}
697 
698 	return ret;
699 }
700 
701 static void __init sort_ftr_regs(void)
702 {
703 	unsigned int i;
704 
705 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
706 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
707 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
708 		unsigned int j = 0;
709 
710 		/*
711 		 * Features here must be sorted in descending order with respect
712 		 * to their shift values and should not overlap with each other.
713 		 */
714 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
715 			unsigned int width = ftr_reg->ftr_bits[j].width;
716 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
717 			unsigned int prev_shift;
718 
719 			WARN((shift  + width) > 64,
720 				"%s has invalid feature at shift %d\n",
721 				ftr_reg->name, shift);
722 
723 			/*
724 			 * Skip the first feature. There is nothing to
725 			 * compare against for now.
726 			 */
727 			if (j == 0)
728 				continue;
729 
730 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
731 			WARN((shift + width) > prev_shift,
732 				"%s has feature overlap at shift %d\n",
733 				ftr_reg->name, shift);
734 		}
735 
736 		/*
737 		 * Skip the first register. There is nothing to
738 		 * compare against for now.
739 		 */
740 		if (i == 0)
741 			continue;
742 		/*
743 		 * Registers here must be sorted in ascending order with respect
744 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
745 		 * to work correctly.
746 		 */
747 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
748 	}
749 }
750 
751 /*
752  * Initialise the CPU feature register from Boot CPU values.
753  * Also initiliases the strict_mask for the register.
754  * Any bits that are not covered by an arm64_ftr_bits entry are considered
755  * RES0 for the system-wide value, and must strictly match.
756  */
757 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
758 {
759 	u64 val = 0;
760 	u64 strict_mask = ~0x0ULL;
761 	u64 user_mask = 0;
762 	u64 valid_mask = 0;
763 
764 	const struct arm64_ftr_bits *ftrp;
765 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
766 
767 	if (!reg)
768 		return;
769 
770 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
771 		u64 ftr_mask = arm64_ftr_mask(ftrp);
772 		s64 ftr_new = arm64_ftr_value(ftrp, new);
773 
774 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
775 
776 		valid_mask |= ftr_mask;
777 		if (!ftrp->strict)
778 			strict_mask &= ~ftr_mask;
779 		if (ftrp->visible)
780 			user_mask |= ftr_mask;
781 		else
782 			reg->user_val = arm64_ftr_set_value(ftrp,
783 							    reg->user_val,
784 							    ftrp->safe_val);
785 	}
786 
787 	val &= valid_mask;
788 
789 	reg->sys_val = val;
790 	reg->strict_mask = strict_mask;
791 	reg->user_mask = user_mask;
792 }
793 
794 extern const struct arm64_cpu_capabilities arm64_errata[];
795 static const struct arm64_cpu_capabilities arm64_features[];
796 
797 static void __init
798 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
799 {
800 	for (; caps->matches; caps++) {
801 		if (WARN(caps->capability >= ARM64_NCAPS,
802 			"Invalid capability %d\n", caps->capability))
803 			continue;
804 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
805 			"Duplicate entry for capability %d\n",
806 			caps->capability))
807 			continue;
808 		cpu_hwcaps_ptrs[caps->capability] = caps;
809 	}
810 }
811 
812 static void __init init_cpu_hwcaps_indirect_list(void)
813 {
814 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
815 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
816 }
817 
818 static void __init setup_boot_cpu_capabilities(void);
819 
820 void __init init_cpu_features(struct cpuinfo_arm64 *info)
821 {
822 	/* Before we start using the tables, make sure it is sorted */
823 	sort_ftr_regs();
824 
825 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
826 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
827 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
828 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
829 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
830 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
831 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
832 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
833 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
834 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
835 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
836 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
837 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
838 
839 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
840 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
841 		init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
842 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
843 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
844 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
845 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
846 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
847 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
848 		init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
849 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
850 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
851 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
852 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
853 		init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
854 		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
855 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
856 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
857 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
858 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
859 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
860 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
861 	}
862 
863 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
864 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
865 		sve_init_vq_map();
866 	}
867 
868 	/*
869 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
870 	 * before we handle the boot CPU below.
871 	 */
872 	init_cpu_hwcaps_indirect_list();
873 
874 	/*
875 	 * Detect and enable early CPU capabilities based on the boot CPU,
876 	 * after we have initialised the CPU feature infrastructure.
877 	 */
878 	setup_boot_cpu_capabilities();
879 }
880 
881 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
882 {
883 	const struct arm64_ftr_bits *ftrp;
884 
885 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
886 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
887 		s64 ftr_new = arm64_ftr_value(ftrp, new);
888 
889 		if (ftr_cur == ftr_new)
890 			continue;
891 		/* Find a safe value */
892 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
893 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
894 	}
895 
896 }
897 
898 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
899 {
900 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
901 
902 	if (!regp)
903 		return 0;
904 
905 	update_cpu_ftr_reg(regp, val);
906 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
907 		return 0;
908 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
909 			regp->name, boot, cpu, val);
910 	return 1;
911 }
912 
913 static void relax_cpu_ftr_reg(u32 sys_id, int field)
914 {
915 	const struct arm64_ftr_bits *ftrp;
916 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
917 
918 	if (!regp)
919 		return;
920 
921 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
922 		if (ftrp->shift == field) {
923 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
924 			break;
925 		}
926 	}
927 
928 	/* Bogus field? */
929 	WARN_ON(!ftrp->width);
930 }
931 
932 static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
933 				     struct cpuinfo_arm64 *boot)
934 {
935 	int taint = 0;
936 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
937 
938 	/*
939 	 * If we don't have AArch32 at all then skip the checks entirely
940 	 * as the register values may be UNKNOWN and we're not going to be
941 	 * using them for anything.
942 	 */
943 	if (!id_aa64pfr0_32bit_el0(pfr0))
944 		return taint;
945 
946 	/*
947 	 * If we don't have AArch32 at EL1, then relax the strictness of
948 	 * EL1-dependent register fields to avoid spurious sanity check fails.
949 	 */
950 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
951 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
952 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
953 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
954 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
955 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
956 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
957 	}
958 
959 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
960 				      info->reg_id_dfr0, boot->reg_id_dfr0);
961 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
962 				      info->reg_id_dfr1, boot->reg_id_dfr1);
963 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
964 				      info->reg_id_isar0, boot->reg_id_isar0);
965 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
966 				      info->reg_id_isar1, boot->reg_id_isar1);
967 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
968 				      info->reg_id_isar2, boot->reg_id_isar2);
969 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
970 				      info->reg_id_isar3, boot->reg_id_isar3);
971 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
972 				      info->reg_id_isar4, boot->reg_id_isar4);
973 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
974 				      info->reg_id_isar5, boot->reg_id_isar5);
975 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
976 				      info->reg_id_isar6, boot->reg_id_isar6);
977 
978 	/*
979 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
980 	 * ACTLR formats could differ across CPUs and therefore would have to
981 	 * be trapped for virtualization anyway.
982 	 */
983 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
984 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
985 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
986 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
987 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
988 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
989 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
990 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
991 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
992 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
993 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
994 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
995 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
996 				      info->reg_id_pfr0, boot->reg_id_pfr0);
997 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
998 				      info->reg_id_pfr1, boot->reg_id_pfr1);
999 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
1000 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1001 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1002 				      info->reg_mvfr0, boot->reg_mvfr0);
1003 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1004 				      info->reg_mvfr1, boot->reg_mvfr1);
1005 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1006 				      info->reg_mvfr2, boot->reg_mvfr2);
1007 
1008 	return taint;
1009 }
1010 
1011 /*
1012  * Update system wide CPU feature registers with the values from a
1013  * non-boot CPU. Also performs SANITY checks to make sure that there
1014  * aren't any insane variations from that of the boot CPU.
1015  */
1016 void update_cpu_features(int cpu,
1017 			 struct cpuinfo_arm64 *info,
1018 			 struct cpuinfo_arm64 *boot)
1019 {
1020 	int taint = 0;
1021 
1022 	/*
1023 	 * The kernel can handle differing I-cache policies, but otherwise
1024 	 * caches should look identical. Userspace JITs will make use of
1025 	 * *minLine.
1026 	 */
1027 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1028 				      info->reg_ctr, boot->reg_ctr);
1029 
1030 	/*
1031 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1032 	 * could result in too much or too little memory being zeroed if a
1033 	 * process is preempted and migrated between CPUs.
1034 	 */
1035 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1036 				      info->reg_dczid, boot->reg_dczid);
1037 
1038 	/* If different, timekeeping will be broken (especially with KVM) */
1039 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1040 				      info->reg_cntfrq, boot->reg_cntfrq);
1041 
1042 	/*
1043 	 * The kernel uses self-hosted debug features and expects CPUs to
1044 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1045 	 * and BRPs to be identical.
1046 	 * ID_AA64DFR1 is currently RES0.
1047 	 */
1048 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1049 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1050 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1051 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1052 	/*
1053 	 * Even in big.LITTLE, processors should be identical instruction-set
1054 	 * wise.
1055 	 */
1056 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1057 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1058 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1059 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1060 
1061 	/*
1062 	 * Differing PARange support is fine as long as all peripherals and
1063 	 * memory are mapped within the minimum PARange of all CPUs.
1064 	 * Linux should not care about secure memory.
1065 	 */
1066 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1067 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1068 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1069 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1070 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1071 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1072 
1073 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1074 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1075 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1076 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1077 
1078 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1079 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1080 
1081 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1082 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1083 					info->reg_zcr, boot->reg_zcr);
1084 
1085 		/* Probe vector lengths, unless we already gave up on SVE */
1086 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1087 		    !system_capabilities_finalized())
1088 			sve_update_vq_map();
1089 	}
1090 
1091 	/*
1092 	 * This relies on a sanitised view of the AArch64 ID registers
1093 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1094 	 */
1095 	taint |= update_32bit_cpu_features(cpu, info, boot);
1096 
1097 	/*
1098 	 * Mismatched CPU features are a recipe for disaster. Don't even
1099 	 * pretend to support them.
1100 	 */
1101 	if (taint) {
1102 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1103 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1104 	}
1105 }
1106 
1107 u64 read_sanitised_ftr_reg(u32 id)
1108 {
1109 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1110 
1111 	if (!regp)
1112 		return 0;
1113 	return regp->sys_val;
1114 }
1115 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
1116 
1117 #define read_sysreg_case(r)	\
1118 	case r:		return read_sysreg_s(r)
1119 
1120 /*
1121  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1122  * Read the system register on the current CPU
1123  */
1124 static u64 __read_sysreg_by_encoding(u32 sys_id)
1125 {
1126 	switch (sys_id) {
1127 	read_sysreg_case(SYS_ID_PFR0_EL1);
1128 	read_sysreg_case(SYS_ID_PFR1_EL1);
1129 	read_sysreg_case(SYS_ID_PFR2_EL1);
1130 	read_sysreg_case(SYS_ID_DFR0_EL1);
1131 	read_sysreg_case(SYS_ID_DFR1_EL1);
1132 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1133 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1134 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1135 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1136 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1137 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1138 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1139 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1140 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1141 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1142 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1143 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1144 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1145 	read_sysreg_case(SYS_MVFR0_EL1);
1146 	read_sysreg_case(SYS_MVFR1_EL1);
1147 	read_sysreg_case(SYS_MVFR2_EL1);
1148 
1149 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1150 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1151 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1152 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1153 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1154 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1155 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1156 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1157 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1158 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1159 
1160 	read_sysreg_case(SYS_CNTFRQ_EL0);
1161 	read_sysreg_case(SYS_CTR_EL0);
1162 	read_sysreg_case(SYS_DCZID_EL0);
1163 
1164 	default:
1165 		BUG();
1166 		return 0;
1167 	}
1168 }
1169 
1170 #include <linux/irqchip/arm-gic-v3.h>
1171 
1172 static bool
1173 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1174 {
1175 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
1176 
1177 	return val >= entry->min_field_value;
1178 }
1179 
1180 static bool
1181 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1182 {
1183 	u64 val;
1184 
1185 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1186 	if (scope == SCOPE_SYSTEM)
1187 		val = read_sanitised_ftr_reg(entry->sys_reg);
1188 	else
1189 		val = __read_sysreg_by_encoding(entry->sys_reg);
1190 
1191 	return feature_matches(val, entry);
1192 }
1193 
1194 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1195 {
1196 	bool has_sre;
1197 
1198 	if (!has_cpuid_feature(entry, scope))
1199 		return false;
1200 
1201 	has_sre = gic_enable_sre();
1202 	if (!has_sre)
1203 		pr_warn_once("%s present but disabled by higher exception level\n",
1204 			     entry->desc);
1205 
1206 	return has_sre;
1207 }
1208 
1209 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1210 {
1211 	u32 midr = read_cpuid_id();
1212 
1213 	/* Cavium ThunderX pass 1.x and 2.x */
1214 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1215 		MIDR_CPU_VAR_REV(0, 0),
1216 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1217 }
1218 
1219 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1220 {
1221 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1222 
1223 	return cpuid_feature_extract_signed_field(pfr0,
1224 					ID_AA64PFR0_FP_SHIFT) < 0;
1225 }
1226 
1227 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1228 			  int scope)
1229 {
1230 	u64 ctr;
1231 
1232 	if (scope == SCOPE_SYSTEM)
1233 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1234 	else
1235 		ctr = read_cpuid_effective_cachetype();
1236 
1237 	return ctr & BIT(CTR_IDC_SHIFT);
1238 }
1239 
1240 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1241 {
1242 	/*
1243 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1244 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1245 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1246 	 * value.
1247 	 */
1248 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1249 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1250 }
1251 
1252 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1253 			  int scope)
1254 {
1255 	u64 ctr;
1256 
1257 	if (scope == SCOPE_SYSTEM)
1258 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1259 	else
1260 		ctr = read_cpuid_cachetype();
1261 
1262 	return ctr & BIT(CTR_DIC_SHIFT);
1263 }
1264 
1265 static bool __maybe_unused
1266 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1267 {
1268 	/*
1269 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1270 	 * may share TLB entries with a CPU stuck in the crashed
1271 	 * kernel.
1272 	 */
1273 	 if (is_kdump_kernel())
1274 		return false;
1275 
1276 	return has_cpuid_feature(entry, scope);
1277 }
1278 
1279 /*
1280  * This check is triggered during the early boot before the cpufeature
1281  * is initialised. Checking the status on the local CPU allows the boot
1282  * CPU to detect the need for non-global mappings and thus avoiding a
1283  * pagetable re-write after all the CPUs are booted. This check will be
1284  * anyway run on individual CPUs, allowing us to get the consistent
1285  * state once the SMP CPUs are up and thus make the switch to non-global
1286  * mappings if required.
1287  */
1288 bool kaslr_requires_kpti(void)
1289 {
1290 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1291 		return false;
1292 
1293 	/*
1294 	 * E0PD does a similar job to KPTI so can be used instead
1295 	 * where available.
1296 	 */
1297 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1298 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1299 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1300 						ID_AA64MMFR2_E0PD_SHIFT))
1301 			return false;
1302 	}
1303 
1304 	/*
1305 	 * Systems affected by Cavium erratum 24756 are incompatible
1306 	 * with KPTI.
1307 	 */
1308 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1309 		extern const struct midr_range cavium_erratum_27456_cpus[];
1310 
1311 		if (is_midr_in_range_list(read_cpuid_id(),
1312 					  cavium_erratum_27456_cpus))
1313 			return false;
1314 	}
1315 
1316 	return kaslr_offset() > 0;
1317 }
1318 
1319 static bool __meltdown_safe = true;
1320 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1321 
1322 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1323 				int scope)
1324 {
1325 	/* List of CPUs that are not vulnerable and don't need KPTI */
1326 	static const struct midr_range kpti_safe_list[] = {
1327 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1328 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1329 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1330 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1331 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1332 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1333 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1334 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1335 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1336 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1337 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1338 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_GOLD),
1339 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
1340 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1341 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1342 		{ /* sentinel */ }
1343 	};
1344 	char const *str = "kpti command line option";
1345 	bool meltdown_safe;
1346 
1347 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1348 
1349 	/* Defer to CPU feature registers */
1350 	if (has_cpuid_feature(entry, scope))
1351 		meltdown_safe = true;
1352 
1353 	if (!meltdown_safe)
1354 		__meltdown_safe = false;
1355 
1356 	/*
1357 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1358 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1359 	 * ends as well as you might imagine. Don't even try.
1360 	 */
1361 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1362 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1363 		__kpti_forced = -1;
1364 	}
1365 
1366 	/* Useful for KASLR robustness */
1367 	if (kaslr_requires_kpti()) {
1368 		if (!__kpti_forced) {
1369 			str = "KASLR";
1370 			__kpti_forced = 1;
1371 		}
1372 	}
1373 
1374 	if (cpu_mitigations_off() && !__kpti_forced) {
1375 		str = "mitigations=off";
1376 		__kpti_forced = -1;
1377 	}
1378 
1379 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1380 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1381 		return false;
1382 	}
1383 
1384 	/* Forced? */
1385 	if (__kpti_forced) {
1386 		pr_info_once("kernel page table isolation forced %s by %s\n",
1387 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1388 		return __kpti_forced > 0;
1389 	}
1390 
1391 	return !meltdown_safe;
1392 }
1393 
1394 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1395 static void
1396 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1397 {
1398 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1399 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1400 	kpti_remap_fn *remap_fn;
1401 
1402 	int cpu = smp_processor_id();
1403 
1404 	/*
1405 	 * We don't need to rewrite the page-tables if either we've done
1406 	 * it already or we have KASLR enabled and therefore have not
1407 	 * created any global mappings at all.
1408 	 */
1409 	if (arm64_use_ng_mappings)
1410 		return;
1411 
1412 	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
1413 
1414 	cpu_install_idmap();
1415 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1416 	cpu_uninstall_idmap();
1417 
1418 	if (!cpu)
1419 		arm64_use_ng_mappings = true;
1420 
1421 	return;
1422 }
1423 #else
1424 static void
1425 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1426 {
1427 }
1428 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1429 
1430 static int __init parse_kpti(char *str)
1431 {
1432 	bool enabled;
1433 	int ret = strtobool(str, &enabled);
1434 
1435 	if (ret)
1436 		return ret;
1437 
1438 	__kpti_forced = enabled ? 1 : -1;
1439 	return 0;
1440 }
1441 early_param("kpti", parse_kpti);
1442 
1443 #ifdef CONFIG_ARM64_HW_AFDBM
1444 static inline void __cpu_enable_hw_dbm(void)
1445 {
1446 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1447 
1448 	write_sysreg(tcr, tcr_el1);
1449 	isb();
1450 	local_flush_tlb_all();
1451 }
1452 
1453 static bool cpu_has_broken_dbm(void)
1454 {
1455 	/* List of CPUs which have broken DBM support. */
1456 	static const struct midr_range cpus[] = {
1457 #ifdef CONFIG_ARM64_ERRATUM_1024718
1458 		MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0),  // A55 r0p0 -r1p0
1459 		/* Kryo4xx Silver (rdpe => r1p0) */
1460 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1461 #endif
1462 		{},
1463 	};
1464 
1465 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1466 }
1467 
1468 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1469 {
1470 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1471 	       !cpu_has_broken_dbm();
1472 }
1473 
1474 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1475 {
1476 	if (cpu_can_use_dbm(cap))
1477 		__cpu_enable_hw_dbm();
1478 }
1479 
1480 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1481 		       int __unused)
1482 {
1483 	static bool detected = false;
1484 	/*
1485 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1486 	 * run a mix of CPUs with and without the feature. So, we
1487 	 * unconditionally enable the capability to allow any late CPU
1488 	 * to use the feature. We only enable the control bits on the
1489 	 * CPU, if it actually supports.
1490 	 *
1491 	 * We have to make sure we print the "feature" detection only
1492 	 * when at least one CPU actually uses it. So check if this CPU
1493 	 * can actually use it and print the message exactly once.
1494 	 *
1495 	 * This is safe as all CPUs (including secondary CPUs - due to the
1496 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1497 	 * goes through the "matches" check exactly once. Also if a CPU
1498 	 * matches the criteria, it is guaranteed that the CPU will turn
1499 	 * the DBM on, as the capability is unconditionally enabled.
1500 	 */
1501 	if (!detected && cpu_can_use_dbm(cap)) {
1502 		detected = true;
1503 		pr_info("detected: Hardware dirty bit management\n");
1504 	}
1505 
1506 	return true;
1507 }
1508 
1509 #endif
1510 
1511 #ifdef CONFIG_ARM64_AMU_EXTN
1512 
1513 /*
1514  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1515  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1516  * information regarding all the events that it supports. When a CPU bit is
1517  * set in the cpumask, the user of this feature can only rely on the presence
1518  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1519  * counters are enabled or access to these counters is enabled by code
1520  * executed at higher exception levels (firmware).
1521  */
1522 static struct cpumask amu_cpus __read_mostly;
1523 
1524 bool cpu_has_amu_feat(int cpu)
1525 {
1526 	return cpumask_test_cpu(cpu, &amu_cpus);
1527 }
1528 
1529 int get_cpu_with_amu_feat(void)
1530 {
1531 	return cpumask_any(&amu_cpus);
1532 }
1533 
1534 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1535 {
1536 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1537 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1538 			smp_processor_id());
1539 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1540 		update_freq_counters_refs();
1541 	}
1542 }
1543 
1544 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1545 		    int __unused)
1546 {
1547 	/*
1548 	 * The AMU extension is a non-conflicting feature: the kernel can
1549 	 * safely run a mix of CPUs with and without support for the
1550 	 * activity monitors extension. Therefore, unconditionally enable
1551 	 * the capability to allow any late CPU to use the feature.
1552 	 *
1553 	 * With this feature unconditionally enabled, the cpu_enable
1554 	 * function will be called for all CPUs that match the criteria,
1555 	 * including secondary and hotplugged, marking this feature as
1556 	 * present on that respective CPU. The enable function will also
1557 	 * print a detection message.
1558 	 */
1559 
1560 	return true;
1561 }
1562 #else
1563 int get_cpu_with_amu_feat(void)
1564 {
1565 	return nr_cpu_ids;
1566 }
1567 #endif
1568 
1569 #ifdef CONFIG_ARM64_VHE
1570 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1571 {
1572 	return is_kernel_in_hyp_mode();
1573 }
1574 
1575 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1576 {
1577 	/*
1578 	 * Copy register values that aren't redirected by hardware.
1579 	 *
1580 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1581 	 * this value to tpidr_el2 before we patch the code. Once we've done
1582 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1583 	 * do anything here.
1584 	 */
1585 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1586 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1587 }
1588 #endif
1589 
1590 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1591 {
1592 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1593 
1594 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1595 	WARN_ON(val & (7 << 27 | 7 << 21));
1596 }
1597 
1598 #ifdef CONFIG_ARM64_PAN
1599 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1600 {
1601 	/*
1602 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1603 	 * is discarded once we return from the exception.
1604 	 */
1605 	WARN_ON_ONCE(in_interrupt());
1606 
1607 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1608 	set_pstate_pan(1);
1609 }
1610 #endif /* CONFIG_ARM64_PAN */
1611 
1612 #ifdef CONFIG_ARM64_RAS_EXTN
1613 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1614 {
1615 	/* Firmware may have left a deferred SError in this register. */
1616 	write_sysreg_s(0, SYS_DISR_EL1);
1617 }
1618 #endif /* CONFIG_ARM64_RAS_EXTN */
1619 
1620 #ifdef CONFIG_ARM64_PTR_AUTH
1621 static bool has_address_auth_cpucap(const struct arm64_cpu_capabilities *entry, int scope)
1622 {
1623 	int boot_val, sec_val;
1624 
1625 	/* We don't expect to be called with SCOPE_SYSTEM */
1626 	WARN_ON(scope == SCOPE_SYSTEM);
1627 	/*
1628 	 * The ptr-auth feature levels are not intercompatible with lower
1629 	 * levels. Hence we must match ptr-auth feature level of the secondary
1630 	 * CPUs with that of the boot CPU. The level of boot cpu is fetched
1631 	 * from the sanitised register whereas direct register read is done for
1632 	 * the secondary CPUs.
1633 	 * The sanitised feature state is guaranteed to match that of the
1634 	 * boot CPU as a mismatched secondary CPU is parked before it gets
1635 	 * a chance to update the state, with the capability.
1636 	 */
1637 	boot_val = cpuid_feature_extract_field(read_sanitised_ftr_reg(entry->sys_reg),
1638 					       entry->field_pos, entry->sign);
1639 	if (scope & SCOPE_BOOT_CPU)
1640 		return boot_val >= entry->min_field_value;
1641 	/* Now check for the secondary CPUs with SCOPE_LOCAL_CPU scope */
1642 	sec_val = cpuid_feature_extract_field(__read_sysreg_by_encoding(entry->sys_reg),
1643 					      entry->field_pos, entry->sign);
1644 	return sec_val == boot_val;
1645 }
1646 
1647 static bool has_address_auth_metacap(const struct arm64_cpu_capabilities *entry,
1648 				     int scope)
1649 {
1650 	return has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_ARCH], scope) ||
1651 	       has_address_auth_cpucap(cpu_hwcaps_ptrs[ARM64_HAS_ADDRESS_AUTH_IMP_DEF], scope);
1652 }
1653 
1654 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1655 			     int __unused)
1656 {
1657 	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
1658 	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1659 }
1660 #endif /* CONFIG_ARM64_PTR_AUTH */
1661 
1662 #ifdef CONFIG_ARM64_E0PD
1663 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1664 {
1665 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1666 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1667 }
1668 #endif /* CONFIG_ARM64_E0PD */
1669 
1670 #ifdef CONFIG_ARM64_PSEUDO_NMI
1671 static bool enable_pseudo_nmi;
1672 
1673 static int __init early_enable_pseudo_nmi(char *p)
1674 {
1675 	return strtobool(p, &enable_pseudo_nmi);
1676 }
1677 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1678 
1679 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1680 				   int scope)
1681 {
1682 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1683 }
1684 #endif
1685 
1686 #ifdef CONFIG_ARM64_BTI
1687 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1688 {
1689 	/*
1690 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1691 	 * function entry points using BR is a requirement for
1692 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1693 	 * So, be strict and forbid other BRs using other registers to
1694 	 * jump onto a PACIxSP instruction:
1695 	 */
1696 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1697 	isb();
1698 }
1699 #endif /* CONFIG_ARM64_BTI */
1700 
1701 #ifdef CONFIG_ARM64_MTE
1702 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
1703 {
1704 	/*
1705 	 * Clear the tags in the zero page. This needs to be done via the
1706 	 * linear map which has the Tagged attribute.
1707 	 */
1708 	if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
1709 		mte_clear_page_tags(lm_alias(empty_zero_page));
1710 
1711 	kasan_init_hw_tags_cpu();
1712 }
1713 #endif /* CONFIG_ARM64_MTE */
1714 
1715 #ifdef CONFIG_KVM
1716 static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
1717 {
1718 	if (kvm_get_mode() != KVM_MODE_PROTECTED)
1719 		return false;
1720 
1721 	if (is_kernel_in_hyp_mode()) {
1722 		pr_warn("Protected KVM not available with VHE\n");
1723 		return false;
1724 	}
1725 
1726 	return true;
1727 }
1728 #endif /* CONFIG_KVM */
1729 
1730 /* Internal helper functions to match cpu capability type */
1731 static bool
1732 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1733 {
1734 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1735 }
1736 
1737 static bool
1738 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1739 {
1740 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1741 }
1742 
1743 static bool
1744 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1745 {
1746 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1747 }
1748 
1749 static const struct arm64_cpu_capabilities arm64_features[] = {
1750 	{
1751 		.desc = "GIC system register CPU interface",
1752 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1753 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1754 		.matches = has_useable_gicv3_cpuif,
1755 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1756 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1757 		.sign = FTR_UNSIGNED,
1758 		.min_field_value = 1,
1759 	},
1760 #ifdef CONFIG_ARM64_PAN
1761 	{
1762 		.desc = "Privileged Access Never",
1763 		.capability = ARM64_HAS_PAN,
1764 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1765 		.matches = has_cpuid_feature,
1766 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1767 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1768 		.sign = FTR_UNSIGNED,
1769 		.min_field_value = 1,
1770 		.cpu_enable = cpu_enable_pan,
1771 	},
1772 #endif /* CONFIG_ARM64_PAN */
1773 #ifdef CONFIG_ARM64_LSE_ATOMICS
1774 	{
1775 		.desc = "LSE atomic instructions",
1776 		.capability = ARM64_HAS_LSE_ATOMICS,
1777 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1778 		.matches = has_cpuid_feature,
1779 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1780 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1781 		.sign = FTR_UNSIGNED,
1782 		.min_field_value = 2,
1783 	},
1784 #endif /* CONFIG_ARM64_LSE_ATOMICS */
1785 	{
1786 		.desc = "Software prefetching using PRFM",
1787 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1788 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1789 		.matches = has_no_hw_prefetch,
1790 	},
1791 #ifdef CONFIG_ARM64_VHE
1792 	{
1793 		.desc = "Virtualization Host Extensions",
1794 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1795 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1796 		.matches = runs_at_el2,
1797 		.cpu_enable = cpu_copy_el2regs,
1798 	},
1799 #endif	/* CONFIG_ARM64_VHE */
1800 	{
1801 		.desc = "32-bit EL0 Support",
1802 		.capability = ARM64_HAS_32BIT_EL0,
1803 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1804 		.matches = has_cpuid_feature,
1805 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1806 		.sign = FTR_UNSIGNED,
1807 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1808 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1809 	},
1810 #ifdef CONFIG_KVM
1811 	{
1812 		.desc = "32-bit EL1 Support",
1813 		.capability = ARM64_HAS_32BIT_EL1,
1814 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1815 		.matches = has_cpuid_feature,
1816 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1817 		.sign = FTR_UNSIGNED,
1818 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
1819 		.min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
1820 	},
1821 	{
1822 		.desc = "Protected KVM",
1823 		.capability = ARM64_KVM_PROTECTED_MODE,
1824 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1825 		.matches = is_kvm_protected_mode,
1826 	},
1827 #endif
1828 	{
1829 		.desc = "Kernel page table isolation (KPTI)",
1830 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1831 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1832 		/*
1833 		 * The ID feature fields below are used to indicate that
1834 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1835 		 * more details.
1836 		 */
1837 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1838 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1839 		.min_field_value = 1,
1840 		.matches = unmap_kernel_at_el0,
1841 		.cpu_enable = kpti_install_ng_mappings,
1842 	},
1843 	{
1844 		/* FP/SIMD is not implemented */
1845 		.capability = ARM64_HAS_NO_FPSIMD,
1846 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1847 		.min_field_value = 0,
1848 		.matches = has_no_fpsimd,
1849 	},
1850 #ifdef CONFIG_ARM64_PMEM
1851 	{
1852 		.desc = "Data cache clean to Point of Persistence",
1853 		.capability = ARM64_HAS_DCPOP,
1854 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1855 		.matches = has_cpuid_feature,
1856 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1857 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1858 		.min_field_value = 1,
1859 	},
1860 	{
1861 		.desc = "Data cache clean to Point of Deep Persistence",
1862 		.capability = ARM64_HAS_DCPODP,
1863 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1864 		.matches = has_cpuid_feature,
1865 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1866 		.sign = FTR_UNSIGNED,
1867 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1868 		.min_field_value = 2,
1869 	},
1870 #endif
1871 #ifdef CONFIG_ARM64_SVE
1872 	{
1873 		.desc = "Scalable Vector Extension",
1874 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1875 		.capability = ARM64_SVE,
1876 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1877 		.sign = FTR_UNSIGNED,
1878 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1879 		.min_field_value = ID_AA64PFR0_SVE,
1880 		.matches = has_cpuid_feature,
1881 		.cpu_enable = sve_kernel_enable,
1882 	},
1883 #endif /* CONFIG_ARM64_SVE */
1884 #ifdef CONFIG_ARM64_RAS_EXTN
1885 	{
1886 		.desc = "RAS Extension Support",
1887 		.capability = ARM64_HAS_RAS_EXTN,
1888 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1889 		.matches = has_cpuid_feature,
1890 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1891 		.sign = FTR_UNSIGNED,
1892 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1893 		.min_field_value = ID_AA64PFR0_RAS_V1,
1894 		.cpu_enable = cpu_clear_disr,
1895 	},
1896 #endif /* CONFIG_ARM64_RAS_EXTN */
1897 #ifdef CONFIG_ARM64_AMU_EXTN
1898 	{
1899 		/*
1900 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
1901 		 * Therefore, don't provide .desc as we don't want the detection
1902 		 * message to be shown until at least one CPU is detected to
1903 		 * support the feature.
1904 		 */
1905 		.capability = ARM64_HAS_AMU_EXTN,
1906 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1907 		.matches = has_amu,
1908 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1909 		.sign = FTR_UNSIGNED,
1910 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
1911 		.min_field_value = ID_AA64PFR0_AMU,
1912 		.cpu_enable = cpu_amu_enable,
1913 	},
1914 #endif /* CONFIG_ARM64_AMU_EXTN */
1915 	{
1916 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1917 		.capability = ARM64_HAS_CACHE_IDC,
1918 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1919 		.matches = has_cache_idc,
1920 		.cpu_enable = cpu_emulate_effective_ctr,
1921 	},
1922 	{
1923 		.desc = "Instruction cache invalidation not required for I/D coherence",
1924 		.capability = ARM64_HAS_CACHE_DIC,
1925 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1926 		.matches = has_cache_dic,
1927 	},
1928 	{
1929 		.desc = "Stage-2 Force Write-Back",
1930 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1931 		.capability = ARM64_HAS_STAGE2_FWB,
1932 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1933 		.sign = FTR_UNSIGNED,
1934 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
1935 		.min_field_value = 1,
1936 		.matches = has_cpuid_feature,
1937 		.cpu_enable = cpu_has_fwb,
1938 	},
1939 	{
1940 		.desc = "ARMv8.4 Translation Table Level",
1941 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1942 		.capability = ARM64_HAS_ARMv8_4_TTL,
1943 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1944 		.sign = FTR_UNSIGNED,
1945 		.field_pos = ID_AA64MMFR2_TTL_SHIFT,
1946 		.min_field_value = 1,
1947 		.matches = has_cpuid_feature,
1948 	},
1949 	{
1950 		.desc = "TLB range maintenance instructions",
1951 		.capability = ARM64_HAS_TLB_RANGE,
1952 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1953 		.matches = has_cpuid_feature,
1954 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1955 		.field_pos = ID_AA64ISAR0_TLB_SHIFT,
1956 		.sign = FTR_UNSIGNED,
1957 		.min_field_value = ID_AA64ISAR0_TLB_RANGE,
1958 	},
1959 #ifdef CONFIG_ARM64_HW_AFDBM
1960 	{
1961 		/*
1962 		 * Since we turn this on always, we don't want the user to
1963 		 * think that the feature is available when it may not be.
1964 		 * So hide the description.
1965 		 *
1966 		 * .desc = "Hardware pagetable Dirty Bit Management",
1967 		 *
1968 		 */
1969 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1970 		.capability = ARM64_HW_DBM,
1971 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1972 		.sign = FTR_UNSIGNED,
1973 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
1974 		.min_field_value = 2,
1975 		.matches = has_hw_dbm,
1976 		.cpu_enable = cpu_enable_hw_dbm,
1977 	},
1978 #endif
1979 	{
1980 		.desc = "CRC32 instructions",
1981 		.capability = ARM64_HAS_CRC32,
1982 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1983 		.matches = has_cpuid_feature,
1984 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1985 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
1986 		.min_field_value = 1,
1987 	},
1988 	{
1989 		.desc = "Speculative Store Bypassing Safe (SSBS)",
1990 		.capability = ARM64_SSBS,
1991 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1992 		.matches = has_cpuid_feature,
1993 		.sys_reg = SYS_ID_AA64PFR1_EL1,
1994 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
1995 		.sign = FTR_UNSIGNED,
1996 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
1997 	},
1998 #ifdef CONFIG_ARM64_CNP
1999 	{
2000 		.desc = "Common not Private translations",
2001 		.capability = ARM64_HAS_CNP,
2002 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2003 		.matches = has_useable_cnp,
2004 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2005 		.sign = FTR_UNSIGNED,
2006 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
2007 		.min_field_value = 1,
2008 		.cpu_enable = cpu_enable_cnp,
2009 	},
2010 #endif
2011 	{
2012 		.desc = "Speculation barrier (SB)",
2013 		.capability = ARM64_HAS_SB,
2014 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2015 		.matches = has_cpuid_feature,
2016 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2017 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
2018 		.sign = FTR_UNSIGNED,
2019 		.min_field_value = 1,
2020 	},
2021 #ifdef CONFIG_ARM64_PTR_AUTH
2022 	{
2023 		.desc = "Address authentication (architected algorithm)",
2024 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
2025 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2026 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2027 		.sign = FTR_UNSIGNED,
2028 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
2029 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
2030 		.matches = has_address_auth_cpucap,
2031 	},
2032 	{
2033 		.desc = "Address authentication (IMP DEF algorithm)",
2034 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2035 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2036 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2037 		.sign = FTR_UNSIGNED,
2038 		.field_pos = ID_AA64ISAR1_API_SHIFT,
2039 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
2040 		.matches = has_address_auth_cpucap,
2041 	},
2042 	{
2043 		.capability = ARM64_HAS_ADDRESS_AUTH,
2044 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2045 		.matches = has_address_auth_metacap,
2046 	},
2047 	{
2048 		.desc = "Generic authentication (architected algorithm)",
2049 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
2050 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2051 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2052 		.sign = FTR_UNSIGNED,
2053 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
2054 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
2055 		.matches = has_cpuid_feature,
2056 	},
2057 	{
2058 		.desc = "Generic authentication (IMP DEF algorithm)",
2059 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2060 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2061 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2062 		.sign = FTR_UNSIGNED,
2063 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
2064 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
2065 		.matches = has_cpuid_feature,
2066 	},
2067 	{
2068 		.capability = ARM64_HAS_GENERIC_AUTH,
2069 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2070 		.matches = has_generic_auth,
2071 	},
2072 #endif /* CONFIG_ARM64_PTR_AUTH */
2073 #ifdef CONFIG_ARM64_PSEUDO_NMI
2074 	{
2075 		/*
2076 		 * Depends on having GICv3
2077 		 */
2078 		.desc = "IRQ priority masking",
2079 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2080 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2081 		.matches = can_use_gic_priorities,
2082 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2083 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2084 		.sign = FTR_UNSIGNED,
2085 		.min_field_value = 1,
2086 	},
2087 #endif
2088 #ifdef CONFIG_ARM64_E0PD
2089 	{
2090 		.desc = "E0PD",
2091 		.capability = ARM64_HAS_E0PD,
2092 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2093 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2094 		.sign = FTR_UNSIGNED,
2095 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2096 		.matches = has_cpuid_feature,
2097 		.min_field_value = 1,
2098 		.cpu_enable = cpu_enable_e0pd,
2099 	},
2100 #endif
2101 #ifdef CONFIG_ARCH_RANDOM
2102 	{
2103 		.desc = "Random Number Generator",
2104 		.capability = ARM64_HAS_RNG,
2105 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2106 		.matches = has_cpuid_feature,
2107 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2108 		.field_pos = ID_AA64ISAR0_RNDR_SHIFT,
2109 		.sign = FTR_UNSIGNED,
2110 		.min_field_value = 1,
2111 	},
2112 #endif
2113 #ifdef CONFIG_ARM64_BTI
2114 	{
2115 		.desc = "Branch Target Identification",
2116 		.capability = ARM64_BTI,
2117 #ifdef CONFIG_ARM64_BTI_KERNEL
2118 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2119 #else
2120 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2121 #endif
2122 		.matches = has_cpuid_feature,
2123 		.cpu_enable = bti_enable,
2124 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2125 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2126 		.min_field_value = ID_AA64PFR1_BT_BTI,
2127 		.sign = FTR_UNSIGNED,
2128 	},
2129 #endif
2130 #ifdef CONFIG_ARM64_MTE
2131 	{
2132 		.desc = "Memory Tagging Extension",
2133 		.capability = ARM64_MTE,
2134 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2135 		.matches = has_cpuid_feature,
2136 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2137 		.field_pos = ID_AA64PFR1_MTE_SHIFT,
2138 		.min_field_value = ID_AA64PFR1_MTE,
2139 		.sign = FTR_UNSIGNED,
2140 		.cpu_enable = cpu_enable_mte,
2141 	},
2142 #endif /* CONFIG_ARM64_MTE */
2143 	{
2144 		.desc = "RCpc load-acquire (LDAPR)",
2145 		.capability = ARM64_HAS_LDAPR,
2146 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2147 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2148 		.sign = FTR_UNSIGNED,
2149 		.field_pos = ID_AA64ISAR1_LRCPC_SHIFT,
2150 		.matches = has_cpuid_feature,
2151 		.min_field_value = 1,
2152 	},
2153 	{},
2154 };
2155 
2156 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
2157 		.matches = has_cpuid_feature,					\
2158 		.sys_reg = reg,							\
2159 		.field_pos = field,						\
2160 		.sign = s,							\
2161 		.min_field_value = min_value,
2162 
2163 #define __HWCAP_CAP(name, cap_type, cap)					\
2164 		.desc = name,							\
2165 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2166 		.hwcap_type = cap_type,						\
2167 		.hwcap = cap,							\
2168 
2169 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
2170 	{									\
2171 		__HWCAP_CAP(#cap, cap_type, cap)				\
2172 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
2173 	}
2174 
2175 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2176 	{									\
2177 		__HWCAP_CAP(#cap, cap_type, cap)				\
2178 		.matches = cpucap_multi_entry_cap_matches,			\
2179 		.match_list = list,						\
2180 	}
2181 
2182 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2183 	{									\
2184 		__HWCAP_CAP(#cap, cap_type, cap)				\
2185 		.matches = match,						\
2186 	}
2187 
2188 #ifdef CONFIG_ARM64_PTR_AUTH
2189 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2190 	{
2191 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2192 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
2193 	},
2194 	{
2195 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2196 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2197 	},
2198 	{},
2199 };
2200 
2201 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2202 	{
2203 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2204 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2205 	},
2206 	{
2207 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2208 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2209 	},
2210 	{},
2211 };
2212 #endif
2213 
2214 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2215 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2216 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2217 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2218 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2219 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2220 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2221 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2222 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2223 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2224 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2225 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2226 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2227 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2228 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2229 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2230 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2231 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2232 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2233 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2234 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2235 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2236 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2237 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2238 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2239 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2240 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2241 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2242 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2243 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2244 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2245 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2246 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2247 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2248 #ifdef CONFIG_ARM64_SVE
2249 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2250 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2251 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2252 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2253 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2254 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2255 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2256 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2257 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2258 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2259 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2260 #endif
2261 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2262 #ifdef CONFIG_ARM64_BTI
2263 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2264 #endif
2265 #ifdef CONFIG_ARM64_PTR_AUTH
2266 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2267 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2268 #endif
2269 #ifdef CONFIG_ARM64_MTE
2270 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE),
2271 #endif /* CONFIG_ARM64_MTE */
2272 	{},
2273 };
2274 
2275 #ifdef CONFIG_COMPAT
2276 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2277 {
2278 	/*
2279 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2280 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2281 	 * check is future proof, by making sure value is non-zero.
2282 	 */
2283 	u32 mvfr1;
2284 
2285 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2286 	if (scope == SCOPE_SYSTEM)
2287 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2288 	else
2289 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2290 
2291 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2292 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2293 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2294 }
2295 #endif
2296 
2297 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2298 #ifdef CONFIG_COMPAT
2299 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2300 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2301 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2302 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2303 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2304 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2305 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2306 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2307 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2308 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2309 #endif
2310 	{},
2311 };
2312 
2313 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2314 {
2315 	switch (cap->hwcap_type) {
2316 	case CAP_HWCAP:
2317 		cpu_set_feature(cap->hwcap);
2318 		break;
2319 #ifdef CONFIG_COMPAT
2320 	case CAP_COMPAT_HWCAP:
2321 		compat_elf_hwcap |= (u32)cap->hwcap;
2322 		break;
2323 	case CAP_COMPAT_HWCAP2:
2324 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2325 		break;
2326 #endif
2327 	default:
2328 		WARN_ON(1);
2329 		break;
2330 	}
2331 }
2332 
2333 /* Check if we have a particular HWCAP enabled */
2334 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2335 {
2336 	bool rc;
2337 
2338 	switch (cap->hwcap_type) {
2339 	case CAP_HWCAP:
2340 		rc = cpu_have_feature(cap->hwcap);
2341 		break;
2342 #ifdef CONFIG_COMPAT
2343 	case CAP_COMPAT_HWCAP:
2344 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2345 		break;
2346 	case CAP_COMPAT_HWCAP2:
2347 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2348 		break;
2349 #endif
2350 	default:
2351 		WARN_ON(1);
2352 		rc = false;
2353 	}
2354 
2355 	return rc;
2356 }
2357 
2358 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2359 {
2360 	/* We support emulation of accesses to CPU ID feature registers */
2361 	cpu_set_named_feature(CPUID);
2362 	for (; hwcaps->matches; hwcaps++)
2363 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2364 			cap_set_elf_hwcap(hwcaps);
2365 }
2366 
2367 static void update_cpu_capabilities(u16 scope_mask)
2368 {
2369 	int i;
2370 	const struct arm64_cpu_capabilities *caps;
2371 
2372 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2373 	for (i = 0; i < ARM64_NCAPS; i++) {
2374 		caps = cpu_hwcaps_ptrs[i];
2375 		if (!caps || !(caps->type & scope_mask) ||
2376 		    cpus_have_cap(caps->capability) ||
2377 		    !caps->matches(caps, cpucap_default_scope(caps)))
2378 			continue;
2379 
2380 		if (caps->desc)
2381 			pr_info("detected: %s\n", caps->desc);
2382 		cpus_set_cap(caps->capability);
2383 
2384 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2385 			set_bit(caps->capability, boot_capabilities);
2386 	}
2387 }
2388 
2389 /*
2390  * Enable all the available capabilities on this CPU. The capabilities
2391  * with BOOT_CPU scope are handled separately and hence skipped here.
2392  */
2393 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2394 {
2395 	int i;
2396 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2397 
2398 	for_each_available_cap(i) {
2399 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2400 
2401 		if (WARN_ON(!cap))
2402 			continue;
2403 
2404 		if (!(cap->type & non_boot_scope))
2405 			continue;
2406 
2407 		if (cap->cpu_enable)
2408 			cap->cpu_enable(cap);
2409 	}
2410 	return 0;
2411 }
2412 
2413 /*
2414  * Run through the enabled capabilities and enable() it on all active
2415  * CPUs
2416  */
2417 static void __init enable_cpu_capabilities(u16 scope_mask)
2418 {
2419 	int i;
2420 	const struct arm64_cpu_capabilities *caps;
2421 	bool boot_scope;
2422 
2423 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2424 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2425 
2426 	for (i = 0; i < ARM64_NCAPS; i++) {
2427 		unsigned int num;
2428 
2429 		caps = cpu_hwcaps_ptrs[i];
2430 		if (!caps || !(caps->type & scope_mask))
2431 			continue;
2432 		num = caps->capability;
2433 		if (!cpus_have_cap(num))
2434 			continue;
2435 
2436 		/* Ensure cpus_have_const_cap(num) works */
2437 		static_branch_enable(&cpu_hwcap_keys[num]);
2438 
2439 		if (boot_scope && caps->cpu_enable)
2440 			/*
2441 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2442 			 * before any secondary CPU boots. Thus, each secondary
2443 			 * will enable the capability as appropriate via
2444 			 * check_local_cpu_capabilities(). The only exception is
2445 			 * the boot CPU, for which the capability must be
2446 			 * enabled here. This approach avoids costly
2447 			 * stop_machine() calls for this case.
2448 			 */
2449 			caps->cpu_enable(caps);
2450 	}
2451 
2452 	/*
2453 	 * For all non-boot scope capabilities, use stop_machine()
2454 	 * as it schedules the work allowing us to modify PSTATE,
2455 	 * instead of on_each_cpu() which uses an IPI, giving us a
2456 	 * PSTATE that disappears when we return.
2457 	 */
2458 	if (!boot_scope)
2459 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2460 			     NULL, cpu_online_mask);
2461 }
2462 
2463 /*
2464  * Run through the list of capabilities to check for conflicts.
2465  * If the system has already detected a capability, take necessary
2466  * action on this CPU.
2467  */
2468 static void verify_local_cpu_caps(u16 scope_mask)
2469 {
2470 	int i;
2471 	bool cpu_has_cap, system_has_cap;
2472 	const struct arm64_cpu_capabilities *caps;
2473 
2474 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2475 
2476 	for (i = 0; i < ARM64_NCAPS; i++) {
2477 		caps = cpu_hwcaps_ptrs[i];
2478 		if (!caps || !(caps->type & scope_mask))
2479 			continue;
2480 
2481 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2482 		system_has_cap = cpus_have_cap(caps->capability);
2483 
2484 		if (system_has_cap) {
2485 			/*
2486 			 * Check if the new CPU misses an advertised feature,
2487 			 * which is not safe to miss.
2488 			 */
2489 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2490 				break;
2491 			/*
2492 			 * We have to issue cpu_enable() irrespective of
2493 			 * whether the CPU has it or not, as it is enabeld
2494 			 * system wide. It is upto the call back to take
2495 			 * appropriate action on this CPU.
2496 			 */
2497 			if (caps->cpu_enable)
2498 				caps->cpu_enable(caps);
2499 		} else {
2500 			/*
2501 			 * Check if the CPU has this capability if it isn't
2502 			 * safe to have when the system doesn't.
2503 			 */
2504 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2505 				break;
2506 		}
2507 	}
2508 
2509 	if (i < ARM64_NCAPS) {
2510 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2511 			smp_processor_id(), caps->capability,
2512 			caps->desc, system_has_cap, cpu_has_cap);
2513 
2514 		if (cpucap_panic_on_conflict(caps))
2515 			cpu_panic_kernel();
2516 		else
2517 			cpu_die_early();
2518 	}
2519 }
2520 
2521 /*
2522  * Check for CPU features that are used in early boot
2523  * based on the Boot CPU value.
2524  */
2525 static void check_early_cpu_features(void)
2526 {
2527 	verify_cpu_asid_bits();
2528 
2529 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2530 }
2531 
2532 static void
2533 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2534 {
2535 
2536 	for (; caps->matches; caps++)
2537 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2538 			pr_crit("CPU%d: missing HWCAP: %s\n",
2539 					smp_processor_id(), caps->desc);
2540 			cpu_die_early();
2541 		}
2542 }
2543 
2544 static void verify_sve_features(void)
2545 {
2546 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2547 	u64 zcr = read_zcr_features();
2548 
2549 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2550 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2551 
2552 	if (len < safe_len || sve_verify_vq_map()) {
2553 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2554 			smp_processor_id());
2555 		cpu_die_early();
2556 	}
2557 
2558 	/* Add checks on other ZCR bits here if necessary */
2559 }
2560 
2561 static void verify_hyp_capabilities(void)
2562 {
2563 	u64 safe_mmfr1, mmfr0, mmfr1;
2564 	int parange, ipa_max;
2565 	unsigned int safe_vmid_bits, vmid_bits;
2566 
2567 	if (!IS_ENABLED(CONFIG_KVM))
2568 		return;
2569 
2570 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2571 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2572 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2573 
2574 	/* Verify VMID bits */
2575 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2576 	vmid_bits = get_vmid_bits(mmfr1);
2577 	if (vmid_bits < safe_vmid_bits) {
2578 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
2579 		cpu_die_early();
2580 	}
2581 
2582 	/* Verify IPA range */
2583 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
2584 				ID_AA64MMFR0_PARANGE_SHIFT);
2585 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
2586 	if (ipa_max < get_kvm_ipa_limit()) {
2587 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
2588 		cpu_die_early();
2589 	}
2590 }
2591 
2592 /*
2593  * Run through the enabled system capabilities and enable() it on this CPU.
2594  * The capabilities were decided based on the available CPUs at the boot time.
2595  * Any new CPU should match the system wide status of the capability. If the
2596  * new CPU doesn't have a capability which the system now has enabled, we
2597  * cannot do anything to fix it up and could cause unexpected failures. So
2598  * we park the CPU.
2599  */
2600 static void verify_local_cpu_capabilities(void)
2601 {
2602 	/*
2603 	 * The capabilities with SCOPE_BOOT_CPU are checked from
2604 	 * check_early_cpu_features(), as they need to be verified
2605 	 * on all secondary CPUs.
2606 	 */
2607 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2608 
2609 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
2610 
2611 	if (system_supports_32bit_el0())
2612 		verify_local_elf_hwcaps(compat_elf_hwcaps);
2613 
2614 	if (system_supports_sve())
2615 		verify_sve_features();
2616 
2617 	if (is_hyp_mode_available())
2618 		verify_hyp_capabilities();
2619 }
2620 
2621 void check_local_cpu_capabilities(void)
2622 {
2623 	/*
2624 	 * All secondary CPUs should conform to the early CPU features
2625 	 * in use by the kernel based on boot CPU.
2626 	 */
2627 	check_early_cpu_features();
2628 
2629 	/*
2630 	 * If we haven't finalised the system capabilities, this CPU gets
2631 	 * a chance to update the errata work arounds and local features.
2632 	 * Otherwise, this CPU should verify that it has all the system
2633 	 * advertised capabilities.
2634 	 */
2635 	if (!system_capabilities_finalized())
2636 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
2637 	else
2638 		verify_local_cpu_capabilities();
2639 }
2640 
2641 static void __init setup_boot_cpu_capabilities(void)
2642 {
2643 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
2644 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
2645 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
2646 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
2647 }
2648 
2649 bool this_cpu_has_cap(unsigned int n)
2650 {
2651 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
2652 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2653 
2654 		if (cap)
2655 			return cap->matches(cap, SCOPE_LOCAL_CPU);
2656 	}
2657 
2658 	return false;
2659 }
2660 
2661 /*
2662  * This helper function is used in a narrow window when,
2663  * - The system wide safe registers are set with all the SMP CPUs and,
2664  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
2665  * In all other cases cpus_have_{const_}cap() should be used.
2666  */
2667 static bool __maybe_unused __system_matches_cap(unsigned int n)
2668 {
2669 	if (n < ARM64_NCAPS) {
2670 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2671 
2672 		if (cap)
2673 			return cap->matches(cap, SCOPE_SYSTEM);
2674 	}
2675 	return false;
2676 }
2677 
2678 void cpu_set_feature(unsigned int num)
2679 {
2680 	WARN_ON(num >= MAX_CPU_FEATURES);
2681 	elf_hwcap |= BIT(num);
2682 }
2683 EXPORT_SYMBOL_GPL(cpu_set_feature);
2684 
2685 bool cpu_have_feature(unsigned int num)
2686 {
2687 	WARN_ON(num >= MAX_CPU_FEATURES);
2688 	return elf_hwcap & BIT(num);
2689 }
2690 EXPORT_SYMBOL_GPL(cpu_have_feature);
2691 
2692 unsigned long cpu_get_elf_hwcap(void)
2693 {
2694 	/*
2695 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2696 	 * note that for userspace compatibility we guarantee that bits 62
2697 	 * and 63 will always be returned as 0.
2698 	 */
2699 	return lower_32_bits(elf_hwcap);
2700 }
2701 
2702 unsigned long cpu_get_elf_hwcap2(void)
2703 {
2704 	return upper_32_bits(elf_hwcap);
2705 }
2706 
2707 static void __init setup_system_capabilities(void)
2708 {
2709 	/*
2710 	 * We have finalised the system-wide safe feature
2711 	 * registers, finalise the capabilities that depend
2712 	 * on it. Also enable all the available capabilities,
2713 	 * that are not enabled already.
2714 	 */
2715 	update_cpu_capabilities(SCOPE_SYSTEM);
2716 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2717 }
2718 
2719 void __init setup_cpu_features(void)
2720 {
2721 	u32 cwg;
2722 
2723 	setup_system_capabilities();
2724 	setup_elf_hwcaps(arm64_elf_hwcaps);
2725 
2726 	if (system_supports_32bit_el0())
2727 		setup_elf_hwcaps(compat_elf_hwcaps);
2728 
2729 	if (system_uses_ttbr0_pan())
2730 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2731 
2732 	sve_setup();
2733 	minsigstksz_setup();
2734 
2735 	/* Advertise that we have computed the system capabilities */
2736 	finalize_system_capabilities();
2737 
2738 	/*
2739 	 * Check for sane CTR_EL0.CWG value.
2740 	 */
2741 	cwg = cache_type_cwg();
2742 	if (!cwg)
2743 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2744 			ARCH_DMA_MINALIGN);
2745 }
2746 
2747 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2748 {
2749 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2750 }
2751 
2752 /*
2753  * We emulate only the following system register space.
2754  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2755  * See Table C5-6 System instruction encodings for System register accesses,
2756  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2757  */
2758 static inline bool __attribute_const__ is_emulated(u32 id)
2759 {
2760 	return (sys_reg_Op0(id) == 0x3 &&
2761 		sys_reg_CRn(id) == 0x0 &&
2762 		sys_reg_Op1(id) == 0x0 &&
2763 		(sys_reg_CRm(id) == 0 ||
2764 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2765 }
2766 
2767 /*
2768  * With CRm == 0, reg should be one of :
2769  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2770  */
2771 static inline int emulate_id_reg(u32 id, u64 *valp)
2772 {
2773 	switch (id) {
2774 	case SYS_MIDR_EL1:
2775 		*valp = read_cpuid_id();
2776 		break;
2777 	case SYS_MPIDR_EL1:
2778 		*valp = SYS_MPIDR_SAFE_VAL;
2779 		break;
2780 	case SYS_REVIDR_EL1:
2781 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2782 		*valp = 0;
2783 		break;
2784 	default:
2785 		return -EINVAL;
2786 	}
2787 
2788 	return 0;
2789 }
2790 
2791 static int emulate_sys_reg(u32 id, u64 *valp)
2792 {
2793 	struct arm64_ftr_reg *regp;
2794 
2795 	if (!is_emulated(id))
2796 		return -EINVAL;
2797 
2798 	if (sys_reg_CRm(id) == 0)
2799 		return emulate_id_reg(id, valp);
2800 
2801 	regp = get_arm64_ftr_reg_nowarn(id);
2802 	if (regp)
2803 		*valp = arm64_ftr_reg_user_value(regp);
2804 	else
2805 		/*
2806 		 * The untracked registers are either IMPLEMENTATION DEFINED
2807 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2808 		 */
2809 		*valp = 0;
2810 	return 0;
2811 }
2812 
2813 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2814 {
2815 	int rc;
2816 	u64 val;
2817 
2818 	rc = emulate_sys_reg(sys_reg, &val);
2819 	if (!rc) {
2820 		pt_regs_write_reg(regs, rt, val);
2821 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2822 	}
2823 	return rc;
2824 }
2825 
2826 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2827 {
2828 	u32 sys_reg, rt;
2829 
2830 	/*
2831 	 * sys_reg values are defined as used in mrs/msr instruction.
2832 	 * shift the imm value to get the encoding.
2833 	 */
2834 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2835 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2836 	return do_emulate_mrs(regs, sys_reg, rt);
2837 }
2838 
2839 static struct undef_hook mrs_hook = {
2840 	.instr_mask = 0xfff00000,
2841 	.instr_val  = 0xd5300000,
2842 	.pstate_mask = PSR_AA32_MODE_MASK,
2843 	.pstate_val = PSR_MODE_EL0t,
2844 	.fn = emulate_mrs,
2845 };
2846 
2847 static int __init enable_mrs_emulation(void)
2848 {
2849 	register_undef_hook(&mrs_hook);
2850 	return 0;
2851 }
2852 
2853 core_initcall(enable_mrs_emulation);
2854 
2855 enum mitigation_state arm64_get_meltdown_state(void)
2856 {
2857 	if (__meltdown_safe)
2858 		return SPECTRE_UNAFFECTED;
2859 
2860 	if (arm64_kernel_unmapped_at_el0())
2861 		return SPECTRE_MITIGATED;
2862 
2863 	return SPECTRE_VULNERABLE;
2864 }
2865 
2866 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2867 			  char *buf)
2868 {
2869 	switch (arm64_get_meltdown_state()) {
2870 	case SPECTRE_UNAFFECTED:
2871 		return sprintf(buf, "Not affected\n");
2872 
2873 	case SPECTRE_MITIGATED:
2874 		return sprintf(buf, "Mitigation: PTI\n");
2875 
2876 	default:
2877 		return sprintf(buf, "Vulnerable\n");
2878 	}
2879 }
2880