xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision 29c37341)
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 <asm/cpu.h>
74 #include <asm/cpufeature.h>
75 #include <asm/cpu_ops.h>
76 #include <asm/fpsimd.h>
77 #include <asm/mmu_context.h>
78 #include <asm/processor.h>
79 #include <asm/sysreg.h>
80 #include <asm/traps.h>
81 #include <asm/virt.h>
82 
83 /* Kernel representation of AT_HWCAP and AT_HWCAP2 */
84 static unsigned long elf_hwcap __read_mostly;
85 
86 #ifdef CONFIG_COMPAT
87 #define COMPAT_ELF_HWCAP_DEFAULT	\
88 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
89 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
90 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_IDIV|\
91 				 COMPAT_HWCAP_LPAE)
92 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
93 unsigned int compat_elf_hwcap2 __read_mostly;
94 #endif
95 
96 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
97 EXPORT_SYMBOL(cpu_hwcaps);
98 static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
99 
100 /* Need also bit for ARM64_CB_PATCH */
101 DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
102 
103 bool arm64_use_ng_mappings = false;
104 EXPORT_SYMBOL(arm64_use_ng_mappings);
105 
106 /*
107  * Flag to indicate if we have computed the system wide
108  * capabilities based on the boot time active CPUs. This
109  * will be used to determine if a new booting CPU should
110  * go through the verification process to make sure that it
111  * supports the system capabilities, without using a hotplug
112  * notifier. This is also used to decide if we could use
113  * the fast path for checking constant CPU caps.
114  */
115 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
116 EXPORT_SYMBOL(arm64_const_caps_ready);
117 static inline void finalize_system_capabilities(void)
118 {
119 	static_branch_enable(&arm64_const_caps_ready);
120 }
121 
122 void dump_cpu_features(void)
123 {
124 	/* file-wide pr_fmt adds "CPU features: " prefix */
125 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
126 }
127 
128 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
129 EXPORT_SYMBOL(cpu_hwcap_keys);
130 
131 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
132 	{						\
133 		.sign = SIGNED,				\
134 		.visible = VISIBLE,			\
135 		.strict = STRICT,			\
136 		.type = TYPE,				\
137 		.shift = SHIFT,				\
138 		.width = WIDTH,				\
139 		.safe_val = SAFE_VAL,			\
140 	}
141 
142 /* Define a feature with unsigned values */
143 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
144 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
145 
146 /* Define a feature with a signed value */
147 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
148 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
149 
150 #define ARM64_FTR_END					\
151 	{						\
152 		.width = 0,				\
153 	}
154 
155 /* meta feature for alternatives */
156 static bool __maybe_unused
157 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
158 
159 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
160 
161 static bool __system_matches_cap(unsigned int n);
162 
163 /*
164  * NOTE: Any changes to the visibility of features should be kept in
165  * sync with the documentation of the CPU feature register ABI.
166  */
167 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
168 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0),
169 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TLB_SHIFT, 4, 0),
170 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
171 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
172 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
173 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
174 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
175 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
176 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
177 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
178 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
179 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
180 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
181 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
182 	ARM64_FTR_END,
183 };
184 
185 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
186 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
187 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DGH_SHIFT, 4, 0),
188 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_BF16_SHIFT, 4, 0),
189 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SPECRES_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
192 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
193 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
194 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
195 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
196 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
197 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
198 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
199 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
200 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_API_SHIFT, 4, 0),
201 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
202 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_APA_SHIFT, 4, 0),
203 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
204 	ARM64_FTR_END,
205 };
206 
207 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
208 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
209 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
210 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
211 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_AMU_SHIFT, 4, 0),
212 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_MPAM_SHIFT, 4, 0),
213 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SEL2_SHIFT, 4, 0),
214 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
215 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
217 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
218 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
219 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
220 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
221 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
222 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
223 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
224 	ARM64_FTR_END,
225 };
226 
227 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
228 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
230 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
231 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
232 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
233 	ARM64_FTR_END,
234 };
235 
236 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
237 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
238 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
239 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
240 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
241 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
242 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
243 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
244 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
245 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
246 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
247 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
248 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BF16_SHIFT, 4, 0),
249 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
250 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
251 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
252 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
253 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
254 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
255 	ARM64_FTR_END,
256 };
257 
258 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
259 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0),
260 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0),
261 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EXS_SHIFT, 4, 0),
262 	/*
263 	 * Page size not being supported at Stage-2 is not fatal. You
264 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
265 	 * your favourite nesting hypervisor.
266 	 *
267 	 * There is a small corner case where the hypervisor explicitly
268 	 * advertises a given granule size at Stage-2 (value 2) on some
269 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
270 	 * vCPUs. Although this is not forbidden by the architecture, it
271 	 * indicates that the hypervisor is being silly (or buggy).
272 	 *
273 	 * We make no effort to cope with this and pretend that if these
274 	 * fields are inconsistent across vCPUs, then it isn't worth
275 	 * trying to bring KVM up.
276 	 */
277 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
278 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
279 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
280 	/*
281 	 * We already refuse to boot CPUs that don't support our configured
282 	 * page size, so we can only detect mismatches for a page size other
283 	 * than the one we're currently using. Unfortunately, SoCs like this
284 	 * exist in the wild so, even though we don't like it, we'll have to go
285 	 * along with it and treat them as non-strict.
286 	 */
287 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
288 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
289 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
290 
291 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
292 	/* Linux shouldn't care about secure memory */
293 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
294 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
295 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
296 	/*
297 	 * Differing PARange is fine as long as all peripherals and memory are mapped
298 	 * within the minimum PARange of all CPUs
299 	 */
300 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
301 	ARM64_FTR_END,
302 };
303 
304 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
305 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_ETS_SHIFT, 4, 0),
306 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_TWED_SHIFT, 4, 0),
307 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_XNX_SHIFT, 4, 0),
308 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64MMFR1_SPECSEI_SHIFT, 4, 0),
309 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
310 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
311 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
312 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
313 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
314 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
315 	ARM64_FTR_END,
316 };
317 
318 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
319 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0),
320 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_EVT_SHIFT, 4, 0),
321 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_BBM_SHIFT, 4, 0),
322 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0),
323 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
324 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IDS_SHIFT, 4, 0),
325 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
326 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_ST_SHIFT, 4, 0),
327 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_NV_SHIFT, 4, 0),
328 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CCIDX_SHIFT, 4, 0),
329 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
330 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
331 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
332 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
333 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
334 	ARM64_FTR_END,
335 };
336 
337 static const struct arm64_ftr_bits ftr_ctr[] = {
338 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
339 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
340 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
341 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
342 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
343 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
344 	/*
345 	 * Linux can handle differing I-cache policies. Userspace JITs will
346 	 * make use of *minLine.
347 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
348 	 */
349 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, CTR_L1IP_SHIFT, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
350 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
351 	ARM64_FTR_END,
352 };
353 
354 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
355 	.name		= "SYS_CTR_EL0",
356 	.ftr_bits	= ftr_ctr
357 };
358 
359 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
360 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_INNERSHR_SHIFT, 4, 0xf),
361 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_FCSE_SHIFT, 4, 0),
362 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_MMFR0_AUXREG_SHIFT, 4, 0),
363 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_TCM_SHIFT, 4, 0),
364 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_SHARELVL_SHIFT, 4, 0),
365 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_OUTERSHR_SHIFT, 4, 0xf),
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_PMSA_SHIFT, 4, 0),
367 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR0_VMSA_SHIFT, 4, 0),
368 	ARM64_FTR_END,
369 };
370 
371 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
372 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_DOUBLELOCK_SHIFT, 4, 0),
373 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
374 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
375 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
376 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
377 	/*
378 	 * We can instantiate multiple PMU instances with different levels
379 	 * of support.
380 	 */
381 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
382 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
383 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
384 	ARM64_FTR_END,
385 };
386 
387 static const struct arm64_ftr_bits ftr_mvfr2[] = {
388 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_FPMISC_SHIFT, 4, 0),
389 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR2_SIMDMISC_SHIFT, 4, 0),
390 	ARM64_FTR_END,
391 };
392 
393 static const struct arm64_ftr_bits ftr_dczid[] = {
394 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, DCZID_DZP_SHIFT, 1, 1),
395 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, DCZID_BS_SHIFT, 4, 0),
396 	ARM64_FTR_END,
397 };
398 
399 static const struct arm64_ftr_bits ftr_id_isar0[] = {
400 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
401 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
402 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
403 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
404 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
405 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
406 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
407 	ARM64_FTR_END,
408 };
409 
410 static const struct arm64_ftr_bits ftr_id_isar5[] = {
411 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
412 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
413 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
414 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
415 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
416 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
417 	ARM64_FTR_END,
418 };
419 
420 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
421 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
422 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
423 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
424 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
427 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_AC2_SHIFT, 4, 0),
428 
429 	/*
430 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
431 	 * external abort on speculative read. It is safe to assume that an
432 	 * SError might be generated than it will not be. Hence it has been
433 	 * classified as FTR_HIGHER_SAFE.
434 	 */
435 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
436 	ARM64_FTR_END,
437 };
438 
439 static const struct arm64_ftr_bits ftr_id_isar4[] = {
440 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
441 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
442 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
443 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
444 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
446 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
447 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
448 	ARM64_FTR_END,
449 };
450 
451 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
452 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
453 	ARM64_FTR_END,
454 };
455 
456 static const struct arm64_ftr_bits ftr_id_isar6[] = {
457 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
458 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
459 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
460 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
462 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
463 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
464 	ARM64_FTR_END,
465 };
466 
467 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
468 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
469 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
470 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE3_SHIFT, 4, 0),
471 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE2_SHIFT, 4, 0),
472 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE1_SHIFT, 4, 0),
473 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_STATE0_SHIFT, 4, 0),
474 	ARM64_FTR_END,
475 };
476 
477 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
478 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
479 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
480 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
481 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
484 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
485 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
486 	ARM64_FTR_END,
487 };
488 
489 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
490 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
491 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
492 	ARM64_FTR_END,
493 };
494 
495 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
496 	/* [31:28] TraceFilt */
497 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_PERFMON_SHIFT, 4, 0xf),
498 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MPROFDBG_SHIFT, 4, 0),
499 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPTRC_SHIFT, 4, 0),
500 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPTRC_SHIFT, 4, 0),
501 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_MMAPDBG_SHIFT, 4, 0),
502 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPSDBG_SHIFT, 4, 0),
503 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR0_COPDBG_SHIFT, 4, 0),
504 	ARM64_FTR_END,
505 };
506 
507 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
508 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
509 	ARM64_FTR_END,
510 };
511 
512 static const struct arm64_ftr_bits ftr_zcr[] = {
513 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
514 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
515 	ARM64_FTR_END,
516 };
517 
518 /*
519  * Common ftr bits for a 32bit register with all hidden, strict
520  * attributes, with 4bit feature fields and a default safe value of
521  * 0. Covers the following 32bit registers:
522  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
523  */
524 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
525 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
526 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
527 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
531 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
532 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
533 	ARM64_FTR_END,
534 };
535 
536 /* Table for a single 32bit feature value */
537 static const struct arm64_ftr_bits ftr_single32[] = {
538 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
539 	ARM64_FTR_END,
540 };
541 
542 static const struct arm64_ftr_bits ftr_raz[] = {
543 	ARM64_FTR_END,
544 };
545 
546 #define ARM64_FTR_REG(id, table) {		\
547 	.sys_id = id,				\
548 	.reg = 	&(struct arm64_ftr_reg){	\
549 		.name = #id,			\
550 		.ftr_bits = &((table)[0]),	\
551 	}}
552 
553 static const struct __ftr_reg_entry {
554 	u32			sys_id;
555 	struct arm64_ftr_reg 	*reg;
556 } arm64_ftr_regs[] = {
557 
558 	/* Op1 = 0, CRn = 0, CRm = 1 */
559 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
560 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
561 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
562 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
563 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
564 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
565 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
566 
567 	/* Op1 = 0, CRn = 0, CRm = 2 */
568 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
569 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
570 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
571 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
572 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
573 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
574 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
575 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
576 
577 	/* Op1 = 0, CRn = 0, CRm = 3 */
578 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
579 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
580 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
581 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
582 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
583 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
584 
585 	/* Op1 = 0, CRn = 0, CRm = 4 */
586 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
587 	ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1),
588 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
589 
590 	/* Op1 = 0, CRn = 0, CRm = 5 */
591 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
592 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
593 
594 	/* Op1 = 0, CRn = 0, CRm = 6 */
595 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
596 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
597 
598 	/* Op1 = 0, CRn = 0, CRm = 7 */
599 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
600 	ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
601 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
602 
603 	/* Op1 = 0, CRn = 1, CRm = 2 */
604 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
605 
606 	/* Op1 = 3, CRn = 0, CRm = 0 */
607 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
608 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
609 
610 	/* Op1 = 3, CRn = 14, CRm = 0 */
611 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
612 };
613 
614 static int search_cmp_ftr_reg(const void *id, const void *regp)
615 {
616 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
617 }
618 
619 /*
620  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
621  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
622  * ascending order of sys_id, we use binary search to find a matching
623  * entry.
624  *
625  * returns - Upon success,  matching ftr_reg entry for id.
626  *         - NULL on failure. It is upto the caller to decide
627  *	     the impact of a failure.
628  */
629 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
630 {
631 	const struct __ftr_reg_entry *ret;
632 
633 	ret = bsearch((const void *)(unsigned long)sys_id,
634 			arm64_ftr_regs,
635 			ARRAY_SIZE(arm64_ftr_regs),
636 			sizeof(arm64_ftr_regs[0]),
637 			search_cmp_ftr_reg);
638 	if (ret)
639 		return ret->reg;
640 	return NULL;
641 }
642 
643 /*
644  * get_arm64_ftr_reg - Looks up a feature register entry using
645  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
646  *
647  * returns - Upon success,  matching ftr_reg entry for id.
648  *         - NULL on failure but with an WARN_ON().
649  */
650 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
651 {
652 	struct arm64_ftr_reg *reg;
653 
654 	reg = get_arm64_ftr_reg_nowarn(sys_id);
655 
656 	/*
657 	 * Requesting a non-existent register search is an error. Warn
658 	 * and let the caller handle it.
659 	 */
660 	WARN_ON(!reg);
661 	return reg;
662 }
663 
664 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
665 			       s64 ftr_val)
666 {
667 	u64 mask = arm64_ftr_mask(ftrp);
668 
669 	reg &= ~mask;
670 	reg |= (ftr_val << ftrp->shift) & mask;
671 	return reg;
672 }
673 
674 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
675 				s64 cur)
676 {
677 	s64 ret = 0;
678 
679 	switch (ftrp->type) {
680 	case FTR_EXACT:
681 		ret = ftrp->safe_val;
682 		break;
683 	case FTR_LOWER_SAFE:
684 		ret = new < cur ? new : cur;
685 		break;
686 	case FTR_HIGHER_OR_ZERO_SAFE:
687 		if (!cur || !new)
688 			break;
689 		/* Fallthrough */
690 	case FTR_HIGHER_SAFE:
691 		ret = new > cur ? new : cur;
692 		break;
693 	default:
694 		BUG();
695 	}
696 
697 	return ret;
698 }
699 
700 static void __init sort_ftr_regs(void)
701 {
702 	unsigned int i;
703 
704 	for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
705 		const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg;
706 		const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits;
707 		unsigned int j = 0;
708 
709 		/*
710 		 * Features here must be sorted in descending order with respect
711 		 * to their shift values and should not overlap with each other.
712 		 */
713 		for (; ftr_bits->width != 0; ftr_bits++, j++) {
714 			unsigned int width = ftr_reg->ftr_bits[j].width;
715 			unsigned int shift = ftr_reg->ftr_bits[j].shift;
716 			unsigned int prev_shift;
717 
718 			WARN((shift  + width) > 64,
719 				"%s has invalid feature at shift %d\n",
720 				ftr_reg->name, shift);
721 
722 			/*
723 			 * Skip the first feature. There is nothing to
724 			 * compare against for now.
725 			 */
726 			if (j == 0)
727 				continue;
728 
729 			prev_shift = ftr_reg->ftr_bits[j - 1].shift;
730 			WARN((shift + width) > prev_shift,
731 				"%s has feature overlap at shift %d\n",
732 				ftr_reg->name, shift);
733 		}
734 
735 		/*
736 		 * Skip the first register. There is nothing to
737 		 * compare against for now.
738 		 */
739 		if (i == 0)
740 			continue;
741 		/*
742 		 * Registers here must be sorted in ascending order with respect
743 		 * to sys_id for subsequent binary search in get_arm64_ftr_reg()
744 		 * to work correctly.
745 		 */
746 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
747 	}
748 }
749 
750 /*
751  * Initialise the CPU feature register from Boot CPU values.
752  * Also initiliases the strict_mask for the register.
753  * Any bits that are not covered by an arm64_ftr_bits entry are considered
754  * RES0 for the system-wide value, and must strictly match.
755  */
756 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
757 {
758 	u64 val = 0;
759 	u64 strict_mask = ~0x0ULL;
760 	u64 user_mask = 0;
761 	u64 valid_mask = 0;
762 
763 	const struct arm64_ftr_bits *ftrp;
764 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
765 
766 	if (!reg)
767 		return;
768 
769 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
770 		u64 ftr_mask = arm64_ftr_mask(ftrp);
771 		s64 ftr_new = arm64_ftr_value(ftrp, new);
772 
773 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
774 
775 		valid_mask |= ftr_mask;
776 		if (!ftrp->strict)
777 			strict_mask &= ~ftr_mask;
778 		if (ftrp->visible)
779 			user_mask |= ftr_mask;
780 		else
781 			reg->user_val = arm64_ftr_set_value(ftrp,
782 							    reg->user_val,
783 							    ftrp->safe_val);
784 	}
785 
786 	val &= valid_mask;
787 
788 	reg->sys_val = val;
789 	reg->strict_mask = strict_mask;
790 	reg->user_mask = user_mask;
791 }
792 
793 extern const struct arm64_cpu_capabilities arm64_errata[];
794 static const struct arm64_cpu_capabilities arm64_features[];
795 
796 static void __init
797 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
798 {
799 	for (; caps->matches; caps++) {
800 		if (WARN(caps->capability >= ARM64_NCAPS,
801 			"Invalid capability %d\n", caps->capability))
802 			continue;
803 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
804 			"Duplicate entry for capability %d\n",
805 			caps->capability))
806 			continue;
807 		cpu_hwcaps_ptrs[caps->capability] = caps;
808 	}
809 }
810 
811 static void __init init_cpu_hwcaps_indirect_list(void)
812 {
813 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
814 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
815 }
816 
817 static void __init setup_boot_cpu_capabilities(void);
818 
819 void __init init_cpu_features(struct cpuinfo_arm64 *info)
820 {
821 	/* Before we start using the tables, make sure it is sorted */
822 	sort_ftr_regs();
823 
824 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
825 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
826 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
827 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
828 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
829 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
830 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
831 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
832 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
833 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
834 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
835 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
836 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
837 
838 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
839 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
840 		init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
841 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
842 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
843 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
844 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
845 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
846 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
847 		init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
848 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
849 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
850 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
851 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
852 		init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
853 		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
854 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
855 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
856 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
857 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
858 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
859 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
860 	}
861 
862 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
863 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
864 		sve_init_vq_map();
865 	}
866 
867 	/*
868 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
869 	 * before we handle the boot CPU below.
870 	 */
871 	init_cpu_hwcaps_indirect_list();
872 
873 	/*
874 	 * Detect and enable early CPU capabilities based on the boot CPU,
875 	 * after we have initialised the CPU feature infrastructure.
876 	 */
877 	setup_boot_cpu_capabilities();
878 }
879 
880 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
881 {
882 	const struct arm64_ftr_bits *ftrp;
883 
884 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
885 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
886 		s64 ftr_new = arm64_ftr_value(ftrp, new);
887 
888 		if (ftr_cur == ftr_new)
889 			continue;
890 		/* Find a safe value */
891 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
892 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
893 	}
894 
895 }
896 
897 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
898 {
899 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
900 
901 	if (!regp)
902 		return 0;
903 
904 	update_cpu_ftr_reg(regp, val);
905 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
906 		return 0;
907 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
908 			regp->name, boot, cpu, val);
909 	return 1;
910 }
911 
912 static void relax_cpu_ftr_reg(u32 sys_id, int field)
913 {
914 	const struct arm64_ftr_bits *ftrp;
915 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
916 
917 	if (!regp)
918 		return;
919 
920 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
921 		if (ftrp->shift == field) {
922 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
923 			break;
924 		}
925 	}
926 
927 	/* Bogus field? */
928 	WARN_ON(!ftrp->width);
929 }
930 
931 static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
932 				     struct cpuinfo_arm64 *boot)
933 {
934 	int taint = 0;
935 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
936 
937 	/*
938 	 * If we don't have AArch32 at all then skip the checks entirely
939 	 * as the register values may be UNKNOWN and we're not going to be
940 	 * using them for anything.
941 	 */
942 	if (!id_aa64pfr0_32bit_el0(pfr0))
943 		return taint;
944 
945 	/*
946 	 * If we don't have AArch32 at EL1, then relax the strictness of
947 	 * EL1-dependent register fields to avoid spurious sanity check fails.
948 	 */
949 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
950 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
951 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
952 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
953 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
954 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
955 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
956 	}
957 
958 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
959 				      info->reg_id_dfr0, boot->reg_id_dfr0);
960 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
961 				      info->reg_id_dfr1, boot->reg_id_dfr1);
962 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
963 				      info->reg_id_isar0, boot->reg_id_isar0);
964 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
965 				      info->reg_id_isar1, boot->reg_id_isar1);
966 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
967 				      info->reg_id_isar2, boot->reg_id_isar2);
968 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
969 				      info->reg_id_isar3, boot->reg_id_isar3);
970 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
971 				      info->reg_id_isar4, boot->reg_id_isar4);
972 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
973 				      info->reg_id_isar5, boot->reg_id_isar5);
974 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
975 				      info->reg_id_isar6, boot->reg_id_isar6);
976 
977 	/*
978 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
979 	 * ACTLR formats could differ across CPUs and therefore would have to
980 	 * be trapped for virtualization anyway.
981 	 */
982 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
983 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
984 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
985 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
986 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
987 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
988 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
989 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
990 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
991 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
992 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
993 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
994 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
995 				      info->reg_id_pfr0, boot->reg_id_pfr0);
996 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
997 				      info->reg_id_pfr1, boot->reg_id_pfr1);
998 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
999 				      info->reg_id_pfr2, boot->reg_id_pfr2);
1000 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
1001 				      info->reg_mvfr0, boot->reg_mvfr0);
1002 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
1003 				      info->reg_mvfr1, boot->reg_mvfr1);
1004 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
1005 				      info->reg_mvfr2, boot->reg_mvfr2);
1006 
1007 	return taint;
1008 }
1009 
1010 /*
1011  * Update system wide CPU feature registers with the values from a
1012  * non-boot CPU. Also performs SANITY checks to make sure that there
1013  * aren't any insane variations from that of the boot CPU.
1014  */
1015 void update_cpu_features(int cpu,
1016 			 struct cpuinfo_arm64 *info,
1017 			 struct cpuinfo_arm64 *boot)
1018 {
1019 	int taint = 0;
1020 
1021 	/*
1022 	 * The kernel can handle differing I-cache policies, but otherwise
1023 	 * caches should look identical. Userspace JITs will make use of
1024 	 * *minLine.
1025 	 */
1026 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
1027 				      info->reg_ctr, boot->reg_ctr);
1028 
1029 	/*
1030 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
1031 	 * could result in too much or too little memory being zeroed if a
1032 	 * process is preempted and migrated between CPUs.
1033 	 */
1034 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
1035 				      info->reg_dczid, boot->reg_dczid);
1036 
1037 	/* If different, timekeeping will be broken (especially with KVM) */
1038 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
1039 				      info->reg_cntfrq, boot->reg_cntfrq);
1040 
1041 	/*
1042 	 * The kernel uses self-hosted debug features and expects CPUs to
1043 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1044 	 * and BRPs to be identical.
1045 	 * ID_AA64DFR1 is currently RES0.
1046 	 */
1047 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1048 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1049 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1050 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1051 	/*
1052 	 * Even in big.LITTLE, processors should be identical instruction-set
1053 	 * wise.
1054 	 */
1055 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1056 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1057 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1058 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1059 
1060 	/*
1061 	 * Differing PARange support is fine as long as all peripherals and
1062 	 * memory are mapped within the minimum PARange of all CPUs.
1063 	 * Linux should not care about secure memory.
1064 	 */
1065 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1066 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1067 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1068 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1069 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1070 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1071 
1072 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1073 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1074 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1075 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1076 
1077 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1078 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1079 
1080 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1081 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1082 					info->reg_zcr, boot->reg_zcr);
1083 
1084 		/* Probe vector lengths, unless we already gave up on SVE */
1085 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1086 		    !system_capabilities_finalized())
1087 			sve_update_vq_map();
1088 	}
1089 
1090 	/*
1091 	 * This relies on a sanitised view of the AArch64 ID registers
1092 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1093 	 */
1094 	taint |= update_32bit_cpu_features(cpu, info, boot);
1095 
1096 	/*
1097 	 * Mismatched CPU features are a recipe for disaster. Don't even
1098 	 * pretend to support them.
1099 	 */
1100 	if (taint) {
1101 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1102 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1103 	}
1104 }
1105 
1106 u64 read_sanitised_ftr_reg(u32 id)
1107 {
1108 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1109 
1110 	if (!regp)
1111 		return 0;
1112 	return regp->sys_val;
1113 }
1114 
1115 #define read_sysreg_case(r)	\
1116 	case r:		return read_sysreg_s(r)
1117 
1118 /*
1119  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1120  * Read the system register on the current CPU
1121  */
1122 static u64 __read_sysreg_by_encoding(u32 sys_id)
1123 {
1124 	switch (sys_id) {
1125 	read_sysreg_case(SYS_ID_PFR0_EL1);
1126 	read_sysreg_case(SYS_ID_PFR1_EL1);
1127 	read_sysreg_case(SYS_ID_PFR2_EL1);
1128 	read_sysreg_case(SYS_ID_DFR0_EL1);
1129 	read_sysreg_case(SYS_ID_DFR1_EL1);
1130 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1131 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1132 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1133 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1134 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1135 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1136 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1137 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1138 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1139 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1140 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1141 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1142 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1143 	read_sysreg_case(SYS_MVFR0_EL1);
1144 	read_sysreg_case(SYS_MVFR1_EL1);
1145 	read_sysreg_case(SYS_MVFR2_EL1);
1146 
1147 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1148 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1149 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1150 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1151 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1152 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1153 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1154 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1155 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1156 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1157 
1158 	read_sysreg_case(SYS_CNTFRQ_EL0);
1159 	read_sysreg_case(SYS_CTR_EL0);
1160 	read_sysreg_case(SYS_DCZID_EL0);
1161 
1162 	default:
1163 		BUG();
1164 		return 0;
1165 	}
1166 }
1167 
1168 #include <linux/irqchip/arm-gic-v3.h>
1169 
1170 static bool
1171 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1172 {
1173 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
1174 
1175 	return val >= entry->min_field_value;
1176 }
1177 
1178 static bool
1179 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1180 {
1181 	u64 val;
1182 
1183 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1184 	if (scope == SCOPE_SYSTEM)
1185 		val = read_sanitised_ftr_reg(entry->sys_reg);
1186 	else
1187 		val = __read_sysreg_by_encoding(entry->sys_reg);
1188 
1189 	return feature_matches(val, entry);
1190 }
1191 
1192 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1193 {
1194 	bool has_sre;
1195 
1196 	if (!has_cpuid_feature(entry, scope))
1197 		return false;
1198 
1199 	has_sre = gic_enable_sre();
1200 	if (!has_sre)
1201 		pr_warn_once("%s present but disabled by higher exception level\n",
1202 			     entry->desc);
1203 
1204 	return has_sre;
1205 }
1206 
1207 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1208 {
1209 	u32 midr = read_cpuid_id();
1210 
1211 	/* Cavium ThunderX pass 1.x and 2.x */
1212 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1213 		MIDR_CPU_VAR_REV(0, 0),
1214 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1215 }
1216 
1217 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1218 {
1219 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1220 
1221 	return cpuid_feature_extract_signed_field(pfr0,
1222 					ID_AA64PFR0_FP_SHIFT) < 0;
1223 }
1224 
1225 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1226 			  int scope)
1227 {
1228 	u64 ctr;
1229 
1230 	if (scope == SCOPE_SYSTEM)
1231 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1232 	else
1233 		ctr = read_cpuid_effective_cachetype();
1234 
1235 	return ctr & BIT(CTR_IDC_SHIFT);
1236 }
1237 
1238 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1239 {
1240 	/*
1241 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1242 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1243 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1244 	 * value.
1245 	 */
1246 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1247 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1248 }
1249 
1250 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1251 			  int scope)
1252 {
1253 	u64 ctr;
1254 
1255 	if (scope == SCOPE_SYSTEM)
1256 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1257 	else
1258 		ctr = read_cpuid_cachetype();
1259 
1260 	return ctr & BIT(CTR_DIC_SHIFT);
1261 }
1262 
1263 static bool __maybe_unused
1264 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1265 {
1266 	/*
1267 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1268 	 * may share TLB entries with a CPU stuck in the crashed
1269 	 * kernel.
1270 	 */
1271 	 if (is_kdump_kernel())
1272 		return false;
1273 
1274 	return has_cpuid_feature(entry, scope);
1275 }
1276 
1277 /*
1278  * This check is triggered during the early boot before the cpufeature
1279  * is initialised. Checking the status on the local CPU allows the boot
1280  * CPU to detect the need for non-global mappings and thus avoiding a
1281  * pagetable re-write after all the CPUs are booted. This check will be
1282  * anyway run on individual CPUs, allowing us to get the consistent
1283  * state once the SMP CPUs are up and thus make the switch to non-global
1284  * mappings if required.
1285  */
1286 bool kaslr_requires_kpti(void)
1287 {
1288 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1289 		return false;
1290 
1291 	/*
1292 	 * E0PD does a similar job to KPTI so can be used instead
1293 	 * where available.
1294 	 */
1295 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1296 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1297 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1298 						ID_AA64MMFR2_E0PD_SHIFT))
1299 			return false;
1300 	}
1301 
1302 	/*
1303 	 * Systems affected by Cavium erratum 24756 are incompatible
1304 	 * with KPTI.
1305 	 */
1306 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1307 		extern const struct midr_range cavium_erratum_27456_cpus[];
1308 
1309 		if (is_midr_in_range_list(read_cpuid_id(),
1310 					  cavium_erratum_27456_cpus))
1311 			return false;
1312 	}
1313 
1314 	return kaslr_offset() > 0;
1315 }
1316 
1317 static bool __meltdown_safe = true;
1318 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1319 
1320 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1321 				int scope)
1322 {
1323 	/* List of CPUs that are not vulnerable and don't need KPTI */
1324 	static const struct midr_range kpti_safe_list[] = {
1325 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1326 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1327 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1328 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1329 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1330 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1331 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1332 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1333 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1334 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1335 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1336 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1337 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1338 		{ /* sentinel */ }
1339 	};
1340 	char const *str = "kpti command line option";
1341 	bool meltdown_safe;
1342 
1343 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1344 
1345 	/* Defer to CPU feature registers */
1346 	if (has_cpuid_feature(entry, scope))
1347 		meltdown_safe = true;
1348 
1349 	if (!meltdown_safe)
1350 		__meltdown_safe = false;
1351 
1352 	/*
1353 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1354 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1355 	 * ends as well as you might imagine. Don't even try.
1356 	 */
1357 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1358 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1359 		__kpti_forced = -1;
1360 	}
1361 
1362 	/* Useful for KASLR robustness */
1363 	if (kaslr_requires_kpti()) {
1364 		if (!__kpti_forced) {
1365 			str = "KASLR";
1366 			__kpti_forced = 1;
1367 		}
1368 	}
1369 
1370 	if (cpu_mitigations_off() && !__kpti_forced) {
1371 		str = "mitigations=off";
1372 		__kpti_forced = -1;
1373 	}
1374 
1375 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1376 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1377 		return false;
1378 	}
1379 
1380 	/* Forced? */
1381 	if (__kpti_forced) {
1382 		pr_info_once("kernel page table isolation forced %s by %s\n",
1383 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1384 		return __kpti_forced > 0;
1385 	}
1386 
1387 	return !meltdown_safe;
1388 }
1389 
1390 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1391 static void
1392 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1393 {
1394 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1395 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1396 	kpti_remap_fn *remap_fn;
1397 
1398 	int cpu = smp_processor_id();
1399 
1400 	/*
1401 	 * We don't need to rewrite the page-tables if either we've done
1402 	 * it already or we have KASLR enabled and therefore have not
1403 	 * created any global mappings at all.
1404 	 */
1405 	if (arm64_use_ng_mappings)
1406 		return;
1407 
1408 	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
1409 
1410 	cpu_install_idmap();
1411 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1412 	cpu_uninstall_idmap();
1413 
1414 	if (!cpu)
1415 		arm64_use_ng_mappings = true;
1416 
1417 	return;
1418 }
1419 #else
1420 static void
1421 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1422 {
1423 }
1424 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1425 
1426 static int __init parse_kpti(char *str)
1427 {
1428 	bool enabled;
1429 	int ret = strtobool(str, &enabled);
1430 
1431 	if (ret)
1432 		return ret;
1433 
1434 	__kpti_forced = enabled ? 1 : -1;
1435 	return 0;
1436 }
1437 early_param("kpti", parse_kpti);
1438 
1439 #ifdef CONFIG_ARM64_HW_AFDBM
1440 static inline void __cpu_enable_hw_dbm(void)
1441 {
1442 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1443 
1444 	write_sysreg(tcr, tcr_el1);
1445 	isb();
1446 }
1447 
1448 static bool cpu_has_broken_dbm(void)
1449 {
1450 	/* List of CPUs which have broken DBM support. */
1451 	static const struct midr_range cpus[] = {
1452 #ifdef CONFIG_ARM64_ERRATUM_1024718
1453 		MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0),  // A55 r0p0 -r1p0
1454 		/* Kryo4xx Silver (rdpe => r1p0) */
1455 		MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
1456 #endif
1457 		{},
1458 	};
1459 
1460 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1461 }
1462 
1463 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1464 {
1465 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1466 	       !cpu_has_broken_dbm();
1467 }
1468 
1469 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1470 {
1471 	if (cpu_can_use_dbm(cap))
1472 		__cpu_enable_hw_dbm();
1473 }
1474 
1475 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1476 		       int __unused)
1477 {
1478 	static bool detected = false;
1479 	/*
1480 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1481 	 * run a mix of CPUs with and without the feature. So, we
1482 	 * unconditionally enable the capability to allow any late CPU
1483 	 * to use the feature. We only enable the control bits on the
1484 	 * CPU, if it actually supports.
1485 	 *
1486 	 * We have to make sure we print the "feature" detection only
1487 	 * when at least one CPU actually uses it. So check if this CPU
1488 	 * can actually use it and print the message exactly once.
1489 	 *
1490 	 * This is safe as all CPUs (including secondary CPUs - due to the
1491 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1492 	 * goes through the "matches" check exactly once. Also if a CPU
1493 	 * matches the criteria, it is guaranteed that the CPU will turn
1494 	 * the DBM on, as the capability is unconditionally enabled.
1495 	 */
1496 	if (!detected && cpu_can_use_dbm(cap)) {
1497 		detected = true;
1498 		pr_info("detected: Hardware dirty bit management\n");
1499 	}
1500 
1501 	return true;
1502 }
1503 
1504 #endif
1505 
1506 #ifdef CONFIG_ARM64_AMU_EXTN
1507 
1508 /*
1509  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1510  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1511  * information regarding all the events that it supports. When a CPU bit is
1512  * set in the cpumask, the user of this feature can only rely on the presence
1513  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1514  * counters are enabled or access to these counters is enabled by code
1515  * executed at higher exception levels (firmware).
1516  */
1517 static struct cpumask amu_cpus __read_mostly;
1518 
1519 bool cpu_has_amu_feat(int cpu)
1520 {
1521 	return cpumask_test_cpu(cpu, &amu_cpus);
1522 }
1523 
1524 /* Initialize the use of AMU counters for frequency invariance */
1525 extern void init_cpu_freq_invariance_counters(void);
1526 
1527 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1528 {
1529 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1530 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1531 			smp_processor_id());
1532 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1533 		init_cpu_freq_invariance_counters();
1534 	}
1535 }
1536 
1537 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1538 		    int __unused)
1539 {
1540 	/*
1541 	 * The AMU extension is a non-conflicting feature: the kernel can
1542 	 * safely run a mix of CPUs with and without support for the
1543 	 * activity monitors extension. Therefore, unconditionally enable
1544 	 * the capability to allow any late CPU to use the feature.
1545 	 *
1546 	 * With this feature unconditionally enabled, the cpu_enable
1547 	 * function will be called for all CPUs that match the criteria,
1548 	 * including secondary and hotplugged, marking this feature as
1549 	 * present on that respective CPU. The enable function will also
1550 	 * print a detection message.
1551 	 */
1552 
1553 	return true;
1554 }
1555 #endif
1556 
1557 #ifdef CONFIG_ARM64_VHE
1558 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1559 {
1560 	return is_kernel_in_hyp_mode();
1561 }
1562 
1563 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1564 {
1565 	/*
1566 	 * Copy register values that aren't redirected by hardware.
1567 	 *
1568 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1569 	 * this value to tpidr_el2 before we patch the code. Once we've done
1570 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1571 	 * do anything here.
1572 	 */
1573 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1574 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1575 }
1576 #endif
1577 
1578 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1579 {
1580 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1581 
1582 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1583 	WARN_ON(val & (7 << 27 | 7 << 21));
1584 }
1585 
1586 #ifdef CONFIG_ARM64_SSBD
1587 static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
1588 {
1589 	if (user_mode(regs))
1590 		return 1;
1591 
1592 	if (instr & BIT(PSTATE_Imm_shift))
1593 		regs->pstate |= PSR_SSBS_BIT;
1594 	else
1595 		regs->pstate &= ~PSR_SSBS_BIT;
1596 
1597 	arm64_skip_faulting_instruction(regs, 4);
1598 	return 0;
1599 }
1600 
1601 static struct undef_hook ssbs_emulation_hook = {
1602 	.instr_mask	= ~(1U << PSTATE_Imm_shift),
1603 	.instr_val	= 0xd500401f | PSTATE_SSBS,
1604 	.fn		= ssbs_emulation_handler,
1605 };
1606 
1607 static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
1608 {
1609 	static bool undef_hook_registered = false;
1610 	static DEFINE_RAW_SPINLOCK(hook_lock);
1611 
1612 	raw_spin_lock(&hook_lock);
1613 	if (!undef_hook_registered) {
1614 		register_undef_hook(&ssbs_emulation_hook);
1615 		undef_hook_registered = true;
1616 	}
1617 	raw_spin_unlock(&hook_lock);
1618 
1619 	if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
1620 		sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
1621 		arm64_set_ssbd_mitigation(false);
1622 	} else {
1623 		arm64_set_ssbd_mitigation(true);
1624 	}
1625 }
1626 #endif /* CONFIG_ARM64_SSBD */
1627 
1628 #ifdef CONFIG_ARM64_PAN
1629 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1630 {
1631 	/*
1632 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1633 	 * is discarded once we return from the exception.
1634 	 */
1635 	WARN_ON_ONCE(in_interrupt());
1636 
1637 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1638 	asm(SET_PSTATE_PAN(1));
1639 }
1640 #endif /* CONFIG_ARM64_PAN */
1641 
1642 #ifdef CONFIG_ARM64_RAS_EXTN
1643 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1644 {
1645 	/* Firmware may have left a deferred SError in this register. */
1646 	write_sysreg_s(0, SYS_DISR_EL1);
1647 }
1648 #endif /* CONFIG_ARM64_RAS_EXTN */
1649 
1650 #ifdef CONFIG_ARM64_PTR_AUTH
1651 static bool has_address_auth(const struct arm64_cpu_capabilities *entry,
1652 			     int __unused)
1653 {
1654 	return __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_ARCH) ||
1655 	       __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_IMP_DEF);
1656 }
1657 
1658 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1659 			     int __unused)
1660 {
1661 	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
1662 	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1663 }
1664 #endif /* CONFIG_ARM64_PTR_AUTH */
1665 
1666 #ifdef CONFIG_ARM64_E0PD
1667 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1668 {
1669 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1670 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1671 }
1672 #endif /* CONFIG_ARM64_E0PD */
1673 
1674 #ifdef CONFIG_ARM64_PSEUDO_NMI
1675 static bool enable_pseudo_nmi;
1676 
1677 static int __init early_enable_pseudo_nmi(char *p)
1678 {
1679 	return strtobool(p, &enable_pseudo_nmi);
1680 }
1681 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1682 
1683 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1684 				   int scope)
1685 {
1686 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1687 }
1688 #endif
1689 
1690 #ifdef CONFIG_ARM64_BTI
1691 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1692 {
1693 	/*
1694 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1695 	 * function entry points using BR is a requirement for
1696 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1697 	 * So, be strict and forbid other BRs using other registers to
1698 	 * jump onto a PACIxSP instruction:
1699 	 */
1700 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1701 	isb();
1702 }
1703 #endif /* CONFIG_ARM64_BTI */
1704 
1705 /* Internal helper functions to match cpu capability type */
1706 static bool
1707 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1708 {
1709 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1710 }
1711 
1712 static bool
1713 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1714 {
1715 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1716 }
1717 
1718 static bool
1719 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1720 {
1721 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1722 }
1723 
1724 static const struct arm64_cpu_capabilities arm64_features[] = {
1725 	{
1726 		.desc = "GIC system register CPU interface",
1727 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1728 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1729 		.matches = has_useable_gicv3_cpuif,
1730 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1731 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1732 		.sign = FTR_UNSIGNED,
1733 		.min_field_value = 1,
1734 	},
1735 #ifdef CONFIG_ARM64_PAN
1736 	{
1737 		.desc = "Privileged Access Never",
1738 		.capability = ARM64_HAS_PAN,
1739 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1740 		.matches = has_cpuid_feature,
1741 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1742 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1743 		.sign = FTR_UNSIGNED,
1744 		.min_field_value = 1,
1745 		.cpu_enable = cpu_enable_pan,
1746 	},
1747 #endif /* CONFIG_ARM64_PAN */
1748 #ifdef CONFIG_ARM64_LSE_ATOMICS
1749 	{
1750 		.desc = "LSE atomic instructions",
1751 		.capability = ARM64_HAS_LSE_ATOMICS,
1752 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1753 		.matches = has_cpuid_feature,
1754 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1755 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1756 		.sign = FTR_UNSIGNED,
1757 		.min_field_value = 2,
1758 	},
1759 #endif /* CONFIG_ARM64_LSE_ATOMICS */
1760 	{
1761 		.desc = "Software prefetching using PRFM",
1762 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1763 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1764 		.matches = has_no_hw_prefetch,
1765 	},
1766 #ifdef CONFIG_ARM64_UAO
1767 	{
1768 		.desc = "User Access Override",
1769 		.capability = ARM64_HAS_UAO,
1770 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1771 		.matches = has_cpuid_feature,
1772 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1773 		.field_pos = ID_AA64MMFR2_UAO_SHIFT,
1774 		.min_field_value = 1,
1775 		/*
1776 		 * We rely on stop_machine() calling uao_thread_switch() to set
1777 		 * UAO immediately after patching.
1778 		 */
1779 	},
1780 #endif /* CONFIG_ARM64_UAO */
1781 #ifdef CONFIG_ARM64_PAN
1782 	{
1783 		.capability = ARM64_ALT_PAN_NOT_UAO,
1784 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1785 		.matches = cpufeature_pan_not_uao,
1786 	},
1787 #endif /* CONFIG_ARM64_PAN */
1788 #ifdef CONFIG_ARM64_VHE
1789 	{
1790 		.desc = "Virtualization Host Extensions",
1791 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1792 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1793 		.matches = runs_at_el2,
1794 		.cpu_enable = cpu_copy_el2regs,
1795 	},
1796 #endif	/* CONFIG_ARM64_VHE */
1797 	{
1798 		.desc = "32-bit EL0 Support",
1799 		.capability = ARM64_HAS_32BIT_EL0,
1800 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1801 		.matches = has_cpuid_feature,
1802 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1803 		.sign = FTR_UNSIGNED,
1804 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1805 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1806 	},
1807 #ifdef CONFIG_KVM
1808 	{
1809 		.desc = "32-bit EL1 Support",
1810 		.capability = ARM64_HAS_32BIT_EL1,
1811 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1812 		.matches = has_cpuid_feature,
1813 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1814 		.sign = FTR_UNSIGNED,
1815 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
1816 		.min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
1817 	},
1818 #endif
1819 	{
1820 		.desc = "Kernel page table isolation (KPTI)",
1821 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1822 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1823 		/*
1824 		 * The ID feature fields below are used to indicate that
1825 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1826 		 * more details.
1827 		 */
1828 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1829 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1830 		.min_field_value = 1,
1831 		.matches = unmap_kernel_at_el0,
1832 		.cpu_enable = kpti_install_ng_mappings,
1833 	},
1834 	{
1835 		/* FP/SIMD is not implemented */
1836 		.capability = ARM64_HAS_NO_FPSIMD,
1837 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1838 		.min_field_value = 0,
1839 		.matches = has_no_fpsimd,
1840 	},
1841 #ifdef CONFIG_ARM64_PMEM
1842 	{
1843 		.desc = "Data cache clean to Point of Persistence",
1844 		.capability = ARM64_HAS_DCPOP,
1845 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1846 		.matches = has_cpuid_feature,
1847 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1848 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1849 		.min_field_value = 1,
1850 	},
1851 	{
1852 		.desc = "Data cache clean to Point of Deep Persistence",
1853 		.capability = ARM64_HAS_DCPODP,
1854 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1855 		.matches = has_cpuid_feature,
1856 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1857 		.sign = FTR_UNSIGNED,
1858 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1859 		.min_field_value = 2,
1860 	},
1861 #endif
1862 #ifdef CONFIG_ARM64_SVE
1863 	{
1864 		.desc = "Scalable Vector Extension",
1865 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1866 		.capability = ARM64_SVE,
1867 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1868 		.sign = FTR_UNSIGNED,
1869 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1870 		.min_field_value = ID_AA64PFR0_SVE,
1871 		.matches = has_cpuid_feature,
1872 		.cpu_enable = sve_kernel_enable,
1873 	},
1874 #endif /* CONFIG_ARM64_SVE */
1875 #ifdef CONFIG_ARM64_RAS_EXTN
1876 	{
1877 		.desc = "RAS Extension Support",
1878 		.capability = ARM64_HAS_RAS_EXTN,
1879 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1880 		.matches = has_cpuid_feature,
1881 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1882 		.sign = FTR_UNSIGNED,
1883 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1884 		.min_field_value = ID_AA64PFR0_RAS_V1,
1885 		.cpu_enable = cpu_clear_disr,
1886 	},
1887 #endif /* CONFIG_ARM64_RAS_EXTN */
1888 #ifdef CONFIG_ARM64_AMU_EXTN
1889 	{
1890 		/*
1891 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
1892 		 * Therefore, don't provide .desc as we don't want the detection
1893 		 * message to be shown until at least one CPU is detected to
1894 		 * support the feature.
1895 		 */
1896 		.capability = ARM64_HAS_AMU_EXTN,
1897 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1898 		.matches = has_amu,
1899 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1900 		.sign = FTR_UNSIGNED,
1901 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
1902 		.min_field_value = ID_AA64PFR0_AMU,
1903 		.cpu_enable = cpu_amu_enable,
1904 	},
1905 #endif /* CONFIG_ARM64_AMU_EXTN */
1906 	{
1907 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1908 		.capability = ARM64_HAS_CACHE_IDC,
1909 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1910 		.matches = has_cache_idc,
1911 		.cpu_enable = cpu_emulate_effective_ctr,
1912 	},
1913 	{
1914 		.desc = "Instruction cache invalidation not required for I/D coherence",
1915 		.capability = ARM64_HAS_CACHE_DIC,
1916 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1917 		.matches = has_cache_dic,
1918 	},
1919 	{
1920 		.desc = "Stage-2 Force Write-Back",
1921 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1922 		.capability = ARM64_HAS_STAGE2_FWB,
1923 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1924 		.sign = FTR_UNSIGNED,
1925 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
1926 		.min_field_value = 1,
1927 		.matches = has_cpuid_feature,
1928 		.cpu_enable = cpu_has_fwb,
1929 	},
1930 	{
1931 		.desc = "ARMv8.4 Translation Table Level",
1932 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1933 		.capability = ARM64_HAS_ARMv8_4_TTL,
1934 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1935 		.sign = FTR_UNSIGNED,
1936 		.field_pos = ID_AA64MMFR2_TTL_SHIFT,
1937 		.min_field_value = 1,
1938 		.matches = has_cpuid_feature,
1939 	},
1940 	{
1941 		.desc = "TLB range maintenance instructions",
1942 		.capability = ARM64_HAS_TLB_RANGE,
1943 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1944 		.matches = has_cpuid_feature,
1945 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1946 		.field_pos = ID_AA64ISAR0_TLB_SHIFT,
1947 		.sign = FTR_UNSIGNED,
1948 		.min_field_value = ID_AA64ISAR0_TLB_RANGE,
1949 	},
1950 #ifdef CONFIG_ARM64_HW_AFDBM
1951 	{
1952 		/*
1953 		 * Since we turn this on always, we don't want the user to
1954 		 * think that the feature is available when it may not be.
1955 		 * So hide the description.
1956 		 *
1957 		 * .desc = "Hardware pagetable Dirty Bit Management",
1958 		 *
1959 		 */
1960 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1961 		.capability = ARM64_HW_DBM,
1962 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1963 		.sign = FTR_UNSIGNED,
1964 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
1965 		.min_field_value = 2,
1966 		.matches = has_hw_dbm,
1967 		.cpu_enable = cpu_enable_hw_dbm,
1968 	},
1969 #endif
1970 	{
1971 		.desc = "CRC32 instructions",
1972 		.capability = ARM64_HAS_CRC32,
1973 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1974 		.matches = has_cpuid_feature,
1975 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1976 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
1977 		.min_field_value = 1,
1978 	},
1979 #ifdef CONFIG_ARM64_SSBD
1980 	{
1981 		.desc = "Speculative Store Bypassing Safe (SSBS)",
1982 		.capability = ARM64_SSBS,
1983 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1984 		.matches = has_cpuid_feature,
1985 		.sys_reg = SYS_ID_AA64PFR1_EL1,
1986 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
1987 		.sign = FTR_UNSIGNED,
1988 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
1989 		.cpu_enable = cpu_enable_ssbs,
1990 	},
1991 #endif
1992 #ifdef CONFIG_ARM64_CNP
1993 	{
1994 		.desc = "Common not Private translations",
1995 		.capability = ARM64_HAS_CNP,
1996 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1997 		.matches = has_useable_cnp,
1998 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1999 		.sign = FTR_UNSIGNED,
2000 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
2001 		.min_field_value = 1,
2002 		.cpu_enable = cpu_enable_cnp,
2003 	},
2004 #endif
2005 	{
2006 		.desc = "Speculation barrier (SB)",
2007 		.capability = ARM64_HAS_SB,
2008 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2009 		.matches = has_cpuid_feature,
2010 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2011 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
2012 		.sign = FTR_UNSIGNED,
2013 		.min_field_value = 1,
2014 	},
2015 #ifdef CONFIG_ARM64_PTR_AUTH
2016 	{
2017 		.desc = "Address authentication (architected algorithm)",
2018 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
2019 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2020 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2021 		.sign = FTR_UNSIGNED,
2022 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
2023 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
2024 		.matches = has_cpuid_feature,
2025 	},
2026 	{
2027 		.desc = "Address authentication (IMP DEF algorithm)",
2028 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
2029 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2030 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2031 		.sign = FTR_UNSIGNED,
2032 		.field_pos = ID_AA64ISAR1_API_SHIFT,
2033 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
2034 		.matches = has_cpuid_feature,
2035 	},
2036 	{
2037 		.capability = ARM64_HAS_ADDRESS_AUTH,
2038 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
2039 		.matches = has_address_auth,
2040 	},
2041 	{
2042 		.desc = "Generic authentication (architected algorithm)",
2043 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
2044 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2045 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2046 		.sign = FTR_UNSIGNED,
2047 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
2048 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
2049 		.matches = has_cpuid_feature,
2050 	},
2051 	{
2052 		.desc = "Generic authentication (IMP DEF algorithm)",
2053 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
2054 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2055 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
2056 		.sign = FTR_UNSIGNED,
2057 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
2058 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
2059 		.matches = has_cpuid_feature,
2060 	},
2061 	{
2062 		.capability = ARM64_HAS_GENERIC_AUTH,
2063 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2064 		.matches = has_generic_auth,
2065 	},
2066 #endif /* CONFIG_ARM64_PTR_AUTH */
2067 #ifdef CONFIG_ARM64_PSEUDO_NMI
2068 	{
2069 		/*
2070 		 * Depends on having GICv3
2071 		 */
2072 		.desc = "IRQ priority masking",
2073 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2074 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2075 		.matches = can_use_gic_priorities,
2076 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2077 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2078 		.sign = FTR_UNSIGNED,
2079 		.min_field_value = 1,
2080 	},
2081 #endif
2082 #ifdef CONFIG_ARM64_E0PD
2083 	{
2084 		.desc = "E0PD",
2085 		.capability = ARM64_HAS_E0PD,
2086 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2087 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2088 		.sign = FTR_UNSIGNED,
2089 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2090 		.matches = has_cpuid_feature,
2091 		.min_field_value = 1,
2092 		.cpu_enable = cpu_enable_e0pd,
2093 	},
2094 #endif
2095 #ifdef CONFIG_ARCH_RANDOM
2096 	{
2097 		.desc = "Random Number Generator",
2098 		.capability = ARM64_HAS_RNG,
2099 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2100 		.matches = has_cpuid_feature,
2101 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2102 		.field_pos = ID_AA64ISAR0_RNDR_SHIFT,
2103 		.sign = FTR_UNSIGNED,
2104 		.min_field_value = 1,
2105 	},
2106 #endif
2107 #ifdef CONFIG_ARM64_BTI
2108 	{
2109 		.desc = "Branch Target Identification",
2110 		.capability = ARM64_BTI,
2111 #ifdef CONFIG_ARM64_BTI_KERNEL
2112 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2113 #else
2114 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2115 #endif
2116 		.matches = has_cpuid_feature,
2117 		.cpu_enable = bti_enable,
2118 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2119 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2120 		.min_field_value = ID_AA64PFR1_BT_BTI,
2121 		.sign = FTR_UNSIGNED,
2122 	},
2123 #endif
2124 	{},
2125 };
2126 
2127 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
2128 		.matches = has_cpuid_feature,					\
2129 		.sys_reg = reg,							\
2130 		.field_pos = field,						\
2131 		.sign = s,							\
2132 		.min_field_value = min_value,
2133 
2134 #define __HWCAP_CAP(name, cap_type, cap)					\
2135 		.desc = name,							\
2136 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2137 		.hwcap_type = cap_type,						\
2138 		.hwcap = cap,							\
2139 
2140 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
2141 	{									\
2142 		__HWCAP_CAP(#cap, cap_type, cap)				\
2143 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
2144 	}
2145 
2146 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2147 	{									\
2148 		__HWCAP_CAP(#cap, cap_type, cap)				\
2149 		.matches = cpucap_multi_entry_cap_matches,			\
2150 		.match_list = list,						\
2151 	}
2152 
2153 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2154 	{									\
2155 		__HWCAP_CAP(#cap, cap_type, cap)				\
2156 		.matches = match,						\
2157 	}
2158 
2159 #ifdef CONFIG_ARM64_PTR_AUTH
2160 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2161 	{
2162 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2163 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
2164 	},
2165 	{
2166 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2167 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2168 	},
2169 	{},
2170 };
2171 
2172 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2173 	{
2174 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2175 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2176 	},
2177 	{
2178 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2179 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2180 	},
2181 	{},
2182 };
2183 #endif
2184 
2185 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2186 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2187 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2188 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2189 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2190 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2191 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2192 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2193 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2194 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2195 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2196 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2197 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2198 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2199 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2200 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2201 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2202 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2203 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2204 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2205 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2206 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2207 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2208 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2209 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2210 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2211 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2212 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2213 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2214 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2215 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2216 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2217 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2218 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2219 #ifdef CONFIG_ARM64_SVE
2220 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2221 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2222 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2223 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2224 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2225 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2226 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2227 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2228 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2229 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2230 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2231 #endif
2232 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2233 #ifdef CONFIG_ARM64_BTI
2234 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2235 #endif
2236 #ifdef CONFIG_ARM64_PTR_AUTH
2237 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2238 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2239 #endif
2240 	{},
2241 };
2242 
2243 #ifdef CONFIG_COMPAT
2244 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2245 {
2246 	/*
2247 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2248 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2249 	 * check is future proof, by making sure value is non-zero.
2250 	 */
2251 	u32 mvfr1;
2252 
2253 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2254 	if (scope == SCOPE_SYSTEM)
2255 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2256 	else
2257 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2258 
2259 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2260 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2261 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2262 }
2263 #endif
2264 
2265 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2266 #ifdef CONFIG_COMPAT
2267 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2268 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2269 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2270 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2271 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2272 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2273 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2274 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2275 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2276 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2277 #endif
2278 	{},
2279 };
2280 
2281 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2282 {
2283 	switch (cap->hwcap_type) {
2284 	case CAP_HWCAP:
2285 		cpu_set_feature(cap->hwcap);
2286 		break;
2287 #ifdef CONFIG_COMPAT
2288 	case CAP_COMPAT_HWCAP:
2289 		compat_elf_hwcap |= (u32)cap->hwcap;
2290 		break;
2291 	case CAP_COMPAT_HWCAP2:
2292 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2293 		break;
2294 #endif
2295 	default:
2296 		WARN_ON(1);
2297 		break;
2298 	}
2299 }
2300 
2301 /* Check if we have a particular HWCAP enabled */
2302 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2303 {
2304 	bool rc;
2305 
2306 	switch (cap->hwcap_type) {
2307 	case CAP_HWCAP:
2308 		rc = cpu_have_feature(cap->hwcap);
2309 		break;
2310 #ifdef CONFIG_COMPAT
2311 	case CAP_COMPAT_HWCAP:
2312 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2313 		break;
2314 	case CAP_COMPAT_HWCAP2:
2315 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2316 		break;
2317 #endif
2318 	default:
2319 		WARN_ON(1);
2320 		rc = false;
2321 	}
2322 
2323 	return rc;
2324 }
2325 
2326 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2327 {
2328 	/* We support emulation of accesses to CPU ID feature registers */
2329 	cpu_set_named_feature(CPUID);
2330 	for (; hwcaps->matches; hwcaps++)
2331 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2332 			cap_set_elf_hwcap(hwcaps);
2333 }
2334 
2335 static void update_cpu_capabilities(u16 scope_mask)
2336 {
2337 	int i;
2338 	const struct arm64_cpu_capabilities *caps;
2339 
2340 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2341 	for (i = 0; i < ARM64_NCAPS; i++) {
2342 		caps = cpu_hwcaps_ptrs[i];
2343 		if (!caps || !(caps->type & scope_mask) ||
2344 		    cpus_have_cap(caps->capability) ||
2345 		    !caps->matches(caps, cpucap_default_scope(caps)))
2346 			continue;
2347 
2348 		if (caps->desc)
2349 			pr_info("detected: %s\n", caps->desc);
2350 		cpus_set_cap(caps->capability);
2351 
2352 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2353 			set_bit(caps->capability, boot_capabilities);
2354 	}
2355 }
2356 
2357 /*
2358  * Enable all the available capabilities on this CPU. The capabilities
2359  * with BOOT_CPU scope are handled separately and hence skipped here.
2360  */
2361 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2362 {
2363 	int i;
2364 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2365 
2366 	for_each_available_cap(i) {
2367 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2368 
2369 		if (WARN_ON(!cap))
2370 			continue;
2371 
2372 		if (!(cap->type & non_boot_scope))
2373 			continue;
2374 
2375 		if (cap->cpu_enable)
2376 			cap->cpu_enable(cap);
2377 	}
2378 	return 0;
2379 }
2380 
2381 /*
2382  * Run through the enabled capabilities and enable() it on all active
2383  * CPUs
2384  */
2385 static void __init enable_cpu_capabilities(u16 scope_mask)
2386 {
2387 	int i;
2388 	const struct arm64_cpu_capabilities *caps;
2389 	bool boot_scope;
2390 
2391 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2392 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2393 
2394 	for (i = 0; i < ARM64_NCAPS; i++) {
2395 		unsigned int num;
2396 
2397 		caps = cpu_hwcaps_ptrs[i];
2398 		if (!caps || !(caps->type & scope_mask))
2399 			continue;
2400 		num = caps->capability;
2401 		if (!cpus_have_cap(num))
2402 			continue;
2403 
2404 		/* Ensure cpus_have_const_cap(num) works */
2405 		static_branch_enable(&cpu_hwcap_keys[num]);
2406 
2407 		if (boot_scope && caps->cpu_enable)
2408 			/*
2409 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2410 			 * before any secondary CPU boots. Thus, each secondary
2411 			 * will enable the capability as appropriate via
2412 			 * check_local_cpu_capabilities(). The only exception is
2413 			 * the boot CPU, for which the capability must be
2414 			 * enabled here. This approach avoids costly
2415 			 * stop_machine() calls for this case.
2416 			 */
2417 			caps->cpu_enable(caps);
2418 	}
2419 
2420 	/*
2421 	 * For all non-boot scope capabilities, use stop_machine()
2422 	 * as it schedules the work allowing us to modify PSTATE,
2423 	 * instead of on_each_cpu() which uses an IPI, giving us a
2424 	 * PSTATE that disappears when we return.
2425 	 */
2426 	if (!boot_scope)
2427 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2428 			     NULL, cpu_online_mask);
2429 }
2430 
2431 /*
2432  * Run through the list of capabilities to check for conflicts.
2433  * If the system has already detected a capability, take necessary
2434  * action on this CPU.
2435  */
2436 static void verify_local_cpu_caps(u16 scope_mask)
2437 {
2438 	int i;
2439 	bool cpu_has_cap, system_has_cap;
2440 	const struct arm64_cpu_capabilities *caps;
2441 
2442 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2443 
2444 	for (i = 0; i < ARM64_NCAPS; i++) {
2445 		caps = cpu_hwcaps_ptrs[i];
2446 		if (!caps || !(caps->type & scope_mask))
2447 			continue;
2448 
2449 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2450 		system_has_cap = cpus_have_cap(caps->capability);
2451 
2452 		if (system_has_cap) {
2453 			/*
2454 			 * Check if the new CPU misses an advertised feature,
2455 			 * which is not safe to miss.
2456 			 */
2457 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2458 				break;
2459 			/*
2460 			 * We have to issue cpu_enable() irrespective of
2461 			 * whether the CPU has it or not, as it is enabeld
2462 			 * system wide. It is upto the call back to take
2463 			 * appropriate action on this CPU.
2464 			 */
2465 			if (caps->cpu_enable)
2466 				caps->cpu_enable(caps);
2467 		} else {
2468 			/*
2469 			 * Check if the CPU has this capability if it isn't
2470 			 * safe to have when the system doesn't.
2471 			 */
2472 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2473 				break;
2474 		}
2475 	}
2476 
2477 	if (i < ARM64_NCAPS) {
2478 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2479 			smp_processor_id(), caps->capability,
2480 			caps->desc, system_has_cap, cpu_has_cap);
2481 
2482 		if (cpucap_panic_on_conflict(caps))
2483 			cpu_panic_kernel();
2484 		else
2485 			cpu_die_early();
2486 	}
2487 }
2488 
2489 /*
2490  * Check for CPU features that are used in early boot
2491  * based on the Boot CPU value.
2492  */
2493 static void check_early_cpu_features(void)
2494 {
2495 	verify_cpu_asid_bits();
2496 
2497 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2498 }
2499 
2500 static void
2501 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2502 {
2503 
2504 	for (; caps->matches; caps++)
2505 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2506 			pr_crit("CPU%d: missing HWCAP: %s\n",
2507 					smp_processor_id(), caps->desc);
2508 			cpu_die_early();
2509 		}
2510 }
2511 
2512 static void verify_sve_features(void)
2513 {
2514 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2515 	u64 zcr = read_zcr_features();
2516 
2517 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2518 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2519 
2520 	if (len < safe_len || sve_verify_vq_map()) {
2521 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2522 			smp_processor_id());
2523 		cpu_die_early();
2524 	}
2525 
2526 	/* Add checks on other ZCR bits here if necessary */
2527 }
2528 
2529 static void verify_hyp_capabilities(void)
2530 {
2531 	u64 safe_mmfr1, mmfr0, mmfr1;
2532 	int parange, ipa_max;
2533 	unsigned int safe_vmid_bits, vmid_bits;
2534 
2535 	if (!IS_ENABLED(CONFIG_KVM) || !IS_ENABLED(CONFIG_KVM_ARM_HOST))
2536 		return;
2537 
2538 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2539 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2540 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2541 
2542 	/* Verify VMID bits */
2543 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2544 	vmid_bits = get_vmid_bits(mmfr1);
2545 	if (vmid_bits < safe_vmid_bits) {
2546 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
2547 		cpu_die_early();
2548 	}
2549 
2550 	/* Verify IPA range */
2551 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
2552 				ID_AA64MMFR0_PARANGE_SHIFT);
2553 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
2554 	if (ipa_max < get_kvm_ipa_limit()) {
2555 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
2556 		cpu_die_early();
2557 	}
2558 }
2559 
2560 /*
2561  * Run through the enabled system capabilities and enable() it on this CPU.
2562  * The capabilities were decided based on the available CPUs at the boot time.
2563  * Any new CPU should match the system wide status of the capability. If the
2564  * new CPU doesn't have a capability which the system now has enabled, we
2565  * cannot do anything to fix it up and could cause unexpected failures. So
2566  * we park the CPU.
2567  */
2568 static void verify_local_cpu_capabilities(void)
2569 {
2570 	/*
2571 	 * The capabilities with SCOPE_BOOT_CPU are checked from
2572 	 * check_early_cpu_features(), as they need to be verified
2573 	 * on all secondary CPUs.
2574 	 */
2575 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2576 
2577 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
2578 
2579 	if (system_supports_32bit_el0())
2580 		verify_local_elf_hwcaps(compat_elf_hwcaps);
2581 
2582 	if (system_supports_sve())
2583 		verify_sve_features();
2584 
2585 	if (is_hyp_mode_available())
2586 		verify_hyp_capabilities();
2587 }
2588 
2589 void check_local_cpu_capabilities(void)
2590 {
2591 	/*
2592 	 * All secondary CPUs should conform to the early CPU features
2593 	 * in use by the kernel based on boot CPU.
2594 	 */
2595 	check_early_cpu_features();
2596 
2597 	/*
2598 	 * If we haven't finalised the system capabilities, this CPU gets
2599 	 * a chance to update the errata work arounds and local features.
2600 	 * Otherwise, this CPU should verify that it has all the system
2601 	 * advertised capabilities.
2602 	 */
2603 	if (!system_capabilities_finalized())
2604 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
2605 	else
2606 		verify_local_cpu_capabilities();
2607 }
2608 
2609 static void __init setup_boot_cpu_capabilities(void)
2610 {
2611 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
2612 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
2613 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
2614 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
2615 }
2616 
2617 bool this_cpu_has_cap(unsigned int n)
2618 {
2619 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
2620 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2621 
2622 		if (cap)
2623 			return cap->matches(cap, SCOPE_LOCAL_CPU);
2624 	}
2625 
2626 	return false;
2627 }
2628 
2629 /*
2630  * This helper function is used in a narrow window when,
2631  * - The system wide safe registers are set with all the SMP CPUs and,
2632  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
2633  * In all other cases cpus_have_{const_}cap() should be used.
2634  */
2635 static bool __system_matches_cap(unsigned int n)
2636 {
2637 	if (n < ARM64_NCAPS) {
2638 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2639 
2640 		if (cap)
2641 			return cap->matches(cap, SCOPE_SYSTEM);
2642 	}
2643 	return false;
2644 }
2645 
2646 void cpu_set_feature(unsigned int num)
2647 {
2648 	WARN_ON(num >= MAX_CPU_FEATURES);
2649 	elf_hwcap |= BIT(num);
2650 }
2651 EXPORT_SYMBOL_GPL(cpu_set_feature);
2652 
2653 bool cpu_have_feature(unsigned int num)
2654 {
2655 	WARN_ON(num >= MAX_CPU_FEATURES);
2656 	return elf_hwcap & BIT(num);
2657 }
2658 EXPORT_SYMBOL_GPL(cpu_have_feature);
2659 
2660 unsigned long cpu_get_elf_hwcap(void)
2661 {
2662 	/*
2663 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2664 	 * note that for userspace compatibility we guarantee that bits 62
2665 	 * and 63 will always be returned as 0.
2666 	 */
2667 	return lower_32_bits(elf_hwcap);
2668 }
2669 
2670 unsigned long cpu_get_elf_hwcap2(void)
2671 {
2672 	return upper_32_bits(elf_hwcap);
2673 }
2674 
2675 static void __init setup_system_capabilities(void)
2676 {
2677 	/*
2678 	 * We have finalised the system-wide safe feature
2679 	 * registers, finalise the capabilities that depend
2680 	 * on it. Also enable all the available capabilities,
2681 	 * that are not enabled already.
2682 	 */
2683 	update_cpu_capabilities(SCOPE_SYSTEM);
2684 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2685 }
2686 
2687 void __init setup_cpu_features(void)
2688 {
2689 	u32 cwg;
2690 
2691 	setup_system_capabilities();
2692 	setup_elf_hwcaps(arm64_elf_hwcaps);
2693 
2694 	if (system_supports_32bit_el0())
2695 		setup_elf_hwcaps(compat_elf_hwcaps);
2696 
2697 	if (system_uses_ttbr0_pan())
2698 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2699 
2700 	sve_setup();
2701 	minsigstksz_setup();
2702 
2703 	/* Advertise that we have computed the system capabilities */
2704 	finalize_system_capabilities();
2705 
2706 	/*
2707 	 * Check for sane CTR_EL0.CWG value.
2708 	 */
2709 	cwg = cache_type_cwg();
2710 	if (!cwg)
2711 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2712 			ARCH_DMA_MINALIGN);
2713 }
2714 
2715 static bool __maybe_unused
2716 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
2717 {
2718 	return (__system_matches_cap(ARM64_HAS_PAN) && !__system_matches_cap(ARM64_HAS_UAO));
2719 }
2720 
2721 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2722 {
2723 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2724 }
2725 
2726 /*
2727  * We emulate only the following system register space.
2728  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2729  * See Table C5-6 System instruction encodings for System register accesses,
2730  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2731  */
2732 static inline bool __attribute_const__ is_emulated(u32 id)
2733 {
2734 	return (sys_reg_Op0(id) == 0x3 &&
2735 		sys_reg_CRn(id) == 0x0 &&
2736 		sys_reg_Op1(id) == 0x0 &&
2737 		(sys_reg_CRm(id) == 0 ||
2738 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2739 }
2740 
2741 /*
2742  * With CRm == 0, reg should be one of :
2743  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2744  */
2745 static inline int emulate_id_reg(u32 id, u64 *valp)
2746 {
2747 	switch (id) {
2748 	case SYS_MIDR_EL1:
2749 		*valp = read_cpuid_id();
2750 		break;
2751 	case SYS_MPIDR_EL1:
2752 		*valp = SYS_MPIDR_SAFE_VAL;
2753 		break;
2754 	case SYS_REVIDR_EL1:
2755 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2756 		*valp = 0;
2757 		break;
2758 	default:
2759 		return -EINVAL;
2760 	}
2761 
2762 	return 0;
2763 }
2764 
2765 static int emulate_sys_reg(u32 id, u64 *valp)
2766 {
2767 	struct arm64_ftr_reg *regp;
2768 
2769 	if (!is_emulated(id))
2770 		return -EINVAL;
2771 
2772 	if (sys_reg_CRm(id) == 0)
2773 		return emulate_id_reg(id, valp);
2774 
2775 	regp = get_arm64_ftr_reg_nowarn(id);
2776 	if (regp)
2777 		*valp = arm64_ftr_reg_user_value(regp);
2778 	else
2779 		/*
2780 		 * The untracked registers are either IMPLEMENTATION DEFINED
2781 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2782 		 */
2783 		*valp = 0;
2784 	return 0;
2785 }
2786 
2787 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2788 {
2789 	int rc;
2790 	u64 val;
2791 
2792 	rc = emulate_sys_reg(sys_reg, &val);
2793 	if (!rc) {
2794 		pt_regs_write_reg(regs, rt, val);
2795 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2796 	}
2797 	return rc;
2798 }
2799 
2800 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2801 {
2802 	u32 sys_reg, rt;
2803 
2804 	/*
2805 	 * sys_reg values are defined as used in mrs/msr instruction.
2806 	 * shift the imm value to get the encoding.
2807 	 */
2808 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2809 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2810 	return do_emulate_mrs(regs, sys_reg, rt);
2811 }
2812 
2813 static struct undef_hook mrs_hook = {
2814 	.instr_mask = 0xfff00000,
2815 	.instr_val  = 0xd5300000,
2816 	.pstate_mask = PSR_AA32_MODE_MASK,
2817 	.pstate_val = PSR_MODE_EL0t,
2818 	.fn = emulate_mrs,
2819 };
2820 
2821 static int __init enable_mrs_emulation(void)
2822 {
2823 	register_undef_hook(&mrs_hook);
2824 	return 0;
2825 }
2826 
2827 core_initcall(enable_mrs_emulation);
2828 
2829 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2830 			  char *buf)
2831 {
2832 	if (__meltdown_safe)
2833 		return sprintf(buf, "Not affected\n");
2834 
2835 	if (arm64_kernel_unmapped_at_el0())
2836 		return sprintf(buf, "Mitigation: PTI\n");
2837 
2838 	return sprintf(buf, "Vulnerable\n");
2839 }
2840