xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision 002dff36)
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 static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p)
123 {
124 	/* file-wide pr_fmt adds "CPU features: " prefix */
125 	pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
126 	return 0;
127 }
128 
129 static struct notifier_block cpu_hwcaps_notifier = {
130 	.notifier_call = dump_cpu_hwcaps
131 };
132 
133 static int __init register_cpu_hwcaps_dumper(void)
134 {
135 	atomic_notifier_chain_register(&panic_notifier_list,
136 				       &cpu_hwcaps_notifier);
137 	return 0;
138 }
139 __initcall(register_cpu_hwcaps_dumper);
140 
141 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
142 EXPORT_SYMBOL(cpu_hwcap_keys);
143 
144 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
145 	{						\
146 		.sign = SIGNED,				\
147 		.visible = VISIBLE,			\
148 		.strict = STRICT,			\
149 		.type = TYPE,				\
150 		.shift = SHIFT,				\
151 		.width = WIDTH,				\
152 		.safe_val = SAFE_VAL,			\
153 	}
154 
155 /* Define a feature with unsigned values */
156 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
157 	__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
158 
159 /* Define a feature with a signed value */
160 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
161 	__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
162 
163 #define ARM64_FTR_END					\
164 	{						\
165 		.width = 0,				\
166 	}
167 
168 /* meta feature for alternatives */
169 static bool __maybe_unused
170 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
171 
172 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
173 
174 static bool __system_matches_cap(unsigned int n);
175 
176 /*
177  * NOTE: Any changes to the visibility of features should be kept in
178  * sync with the documentation of the CPU feature register ABI.
179  */
180 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
181 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0),
182 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TLB_SHIFT, 4, 0),
183 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
184 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
185 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
186 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
187 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
188 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
189 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
190 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
191 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
192 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
193 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
194 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
195 	ARM64_FTR_END,
196 };
197 
198 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
199 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
200 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DGH_SHIFT, 4, 0),
201 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_BF16_SHIFT, 4, 0),
202 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SPECRES_SHIFT, 4, 0),
203 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
204 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
205 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
206 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
207 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
208 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
209 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
210 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
211 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
212 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
213 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_API_SHIFT, 4, 0),
214 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
215 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_APA_SHIFT, 4, 0),
216 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
217 	ARM64_FTR_END,
218 };
219 
220 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
221 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
222 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
223 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
224 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_AMU_SHIFT, 4, 0),
225 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_MPAM_SHIFT, 4, 0),
226 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SEL2_SHIFT, 4, 0),
227 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
228 				   FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
229 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
230 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
231 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
232 	S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
233 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
234 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
235 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
236 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
237 	ARM64_FTR_END,
238 };
239 
240 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
241 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
242 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
243 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
244 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
245 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
246 	ARM64_FTR_END,
247 };
248 
249 static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
250 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
251 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
252 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
253 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
254 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
255 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
256 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
257 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
258 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
259 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
260 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
261 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BF16_SHIFT, 4, 0),
262 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
263 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
264 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
265 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
266 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
267 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
268 	ARM64_FTR_END,
269 };
270 
271 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
272 	/*
273 	 * Page size not being supported at Stage-2 is not fatal. You
274 	 * just give up KVM if PAGE_SIZE isn't supported there. Go fix
275 	 * your favourite nesting hypervisor.
276 	 *
277 	 * There is a small corner case where the hypervisor explicitly
278 	 * advertises a given granule size at Stage-2 (value 2) on some
279 	 * vCPUs, and uses the fallback to Stage-1 (value 0) for other
280 	 * vCPUs. Although this is not forbidden by the architecture, it
281 	 * indicates that the hypervisor is being silly (or buggy).
282 	 *
283 	 * We make no effort to cope with this and pretend that if these
284 	 * fields are inconsistent across vCPUs, then it isn't worth
285 	 * trying to bring KVM up.
286 	 */
287 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
288 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
289 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
290 	/*
291 	 * We already refuse to boot CPUs that don't support our configured
292 	 * page size, so we can only detect mismatches for a page size other
293 	 * than the one we're currently using. Unfortunately, SoCs like this
294 	 * exist in the wild so, even though we don't like it, we'll have to go
295 	 * along with it and treat them as non-strict.
296 	 */
297 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
298 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
299 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
300 
301 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
302 	/* Linux shouldn't care about secure memory */
303 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
304 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
305 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
306 	/*
307 	 * Differing PARange is fine as long as all peripherals and memory are mapped
308 	 * within the minimum PARange of all CPUs
309 	 */
310 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
311 	ARM64_FTR_END,
312 };
313 
314 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
315 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
316 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
317 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
318 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
319 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
320 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
321 	ARM64_FTR_END,
322 };
323 
324 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
325 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0),
326 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
327 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
328 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
329 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
330 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
331 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
332 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
333 	ARM64_FTR_END,
334 };
335 
336 static const struct arm64_ftr_bits ftr_ctr[] = {
337 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
338 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
339 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
340 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
341 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
342 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
343 	/*
344 	 * Linux can handle differing I-cache policies. Userspace JITs will
345 	 * make use of *minLine.
346 	 * If we have differing I-cache policies, report it as the weakest - VIPT.
347 	 */
348 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT),	/* L1Ip */
349 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
350 	ARM64_FTR_END,
351 };
352 
353 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
354 	.name		= "SYS_CTR_EL0",
355 	.ftr_bits	= ftr_ctr
356 };
357 
358 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
359 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0xf),	/* InnerShr */
360 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),	/* FCSE */
361 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),	/* AuxReg */
362 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),	/* TCM */
363 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),	/* ShareLvl */
364 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0xf),	/* OuterShr */
365 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),	/* PMSA */
366 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* VMSA */
367 	ARM64_FTR_END,
368 };
369 
370 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
371 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 36, 4, 0),
372 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
373 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
374 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
375 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
376 	/*
377 	 * We can instantiate multiple PMU instances with different levels
378 	 * of support.
379 	 */
380 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
381 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
382 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
383 	ARM64_FTR_END,
384 };
385 
386 static const struct arm64_ftr_bits ftr_mvfr2[] = {
387 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),		/* FPMisc */
388 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),		/* SIMDMisc */
389 	ARM64_FTR_END,
390 };
391 
392 static const struct arm64_ftr_bits ftr_dczid[] = {
393 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 4, 1, 1),		/* DZP */
394 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* BS */
395 	ARM64_FTR_END,
396 };
397 
398 static const struct arm64_ftr_bits ftr_id_isar0[] = {
399 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DIVIDE_SHIFT, 4, 0),
400 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_DEBUG_SHIFT, 4, 0),
401 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_COPROC_SHIFT, 4, 0),
402 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_CMPBRANCH_SHIFT, 4, 0),
403 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITFIELD_SHIFT, 4, 0),
404 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_BITCOUNT_SHIFT, 4, 0),
405 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR0_SWAP_SHIFT, 4, 0),
406 	ARM64_FTR_END,
407 };
408 
409 static const struct arm64_ftr_bits ftr_id_isar5[] = {
410 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
411 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
412 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
413 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
414 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
415 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
416 	ARM64_FTR_END,
417 };
418 
419 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
420 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
421 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
422 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
423 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
424 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
425 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
426 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),	/* ac2 */
427 	/*
428 	 * SpecSEI = 1 indicates that the PE might generate an SError on an
429 	 * external abort on speculative read. It is safe to assume that an
430 	 * SError might be generated than it will not be. Hence it has been
431 	 * classified as FTR_HIGHER_SAFE.
432 	 */
433 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_MMFR4_SPECSEI_SHIFT, 4, 0),
434 	ARM64_FTR_END,
435 };
436 
437 static const struct arm64_ftr_bits ftr_id_isar4[] = {
438 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SWP_FRAC_SHIFT, 4, 0),
439 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_PSR_M_SHIFT, 4, 0),
440 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SYNCH_PRIM_FRAC_SHIFT, 4, 0),
441 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_BARRIER_SHIFT, 4, 0),
442 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_SMC_SHIFT, 4, 0),
443 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WRITEBACK_SHIFT, 4, 0),
444 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_WITHSHIFTS_SHIFT, 4, 0),
445 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR4_UNPRIV_SHIFT, 4, 0),
446 	ARM64_FTR_END,
447 };
448 
449 static const struct arm64_ftr_bits ftr_id_mmfr5[] = {
450 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR5_ETS_SHIFT, 4, 0),
451 	ARM64_FTR_END,
452 };
453 
454 static const struct arm64_ftr_bits ftr_id_isar6[] = {
455 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_I8MM_SHIFT, 4, 0),
456 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_BF16_SHIFT, 4, 0),
457 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SPECRES_SHIFT, 4, 0),
458 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_SB_SHIFT, 4, 0),
459 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_FHM_SHIFT, 4, 0),
460 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_DP_SHIFT, 4, 0),
461 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR6_JSCVT_SHIFT, 4, 0),
462 	ARM64_FTR_END,
463 };
464 
465 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
466 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR0_DIT_SHIFT, 4, 0),
467 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR0_CSV2_SHIFT, 4, 0),
468 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),		/* State3 */
469 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),		/* State2 */
470 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),		/* State1 */
471 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),		/* State0 */
472 	ARM64_FTR_END,
473 };
474 
475 static const struct arm64_ftr_bits ftr_id_pfr1[] = {
476 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GIC_SHIFT, 4, 0),
477 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRT_FRAC_SHIFT, 4, 0),
478 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SEC_FRAC_SHIFT, 4, 0),
479 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_GENTIMER_SHIFT, 4, 0),
480 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_VIRTUALIZATION_SHIFT, 4, 0),
481 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_MPROGMOD_SHIFT, 4, 0),
482 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_SECURITY_SHIFT, 4, 0),
483 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR1_PROGMOD_SHIFT, 4, 0),
484 	ARM64_FTR_END,
485 };
486 
487 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
488 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
489 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
490 	ARM64_FTR_END,
491 };
492 
493 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
494 	/* [31:28] TraceFilt */
495 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf),	/* PerfMon */
496 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
497 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
498 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
499 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
500 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
501 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
502 	ARM64_FTR_END,
503 };
504 
505 static const struct arm64_ftr_bits ftr_id_dfr1[] = {
506 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
507 	ARM64_FTR_END,
508 };
509 
510 static const struct arm64_ftr_bits ftr_zcr[] = {
511 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
512 		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),	/* LEN */
513 	ARM64_FTR_END,
514 };
515 
516 /*
517  * Common ftr bits for a 32bit register with all hidden, strict
518  * attributes, with 4bit feature fields and a default safe value of
519  * 0. Covers the following 32bit registers:
520  * id_isar[1-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
521  */
522 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
523 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
524 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
525 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
526 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
527 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
528 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
529 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
530 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
531 	ARM64_FTR_END,
532 };
533 
534 /* Table for a single 32bit feature value */
535 static const struct arm64_ftr_bits ftr_single32[] = {
536 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
537 	ARM64_FTR_END,
538 };
539 
540 static const struct arm64_ftr_bits ftr_raz[] = {
541 	ARM64_FTR_END,
542 };
543 
544 #define ARM64_FTR_REG(id, table) {		\
545 	.sys_id = id,				\
546 	.reg = 	&(struct arm64_ftr_reg){	\
547 		.name = #id,			\
548 		.ftr_bits = &((table)[0]),	\
549 	}}
550 
551 static const struct __ftr_reg_entry {
552 	u32			sys_id;
553 	struct arm64_ftr_reg 	*reg;
554 } arm64_ftr_regs[] = {
555 
556 	/* Op1 = 0, CRn = 0, CRm = 1 */
557 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
558 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_id_pfr1),
559 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
560 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
561 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
562 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
563 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
564 
565 	/* Op1 = 0, CRn = 0, CRm = 2 */
566 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_id_isar0),
567 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
568 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
569 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
570 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_id_isar4),
571 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
572 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
573 	ARM64_FTR_REG(SYS_ID_ISAR6_EL1, ftr_id_isar6),
574 
575 	/* Op1 = 0, CRn = 0, CRm = 3 */
576 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
577 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
578 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
579 	ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
580 	ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
581 	ARM64_FTR_REG(SYS_ID_MMFR5_EL1, ftr_id_mmfr5),
582 
583 	/* Op1 = 0, CRn = 0, CRm = 4 */
584 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
585 	ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1),
586 	ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
587 
588 	/* Op1 = 0, CRn = 0, CRm = 5 */
589 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
590 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
591 
592 	/* Op1 = 0, CRn = 0, CRm = 6 */
593 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
594 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
595 
596 	/* Op1 = 0, CRn = 0, CRm = 7 */
597 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
598 	ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
599 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
600 
601 	/* Op1 = 0, CRn = 1, CRm = 2 */
602 	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
603 
604 	/* Op1 = 3, CRn = 0, CRm = 0 */
605 	{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
606 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
607 
608 	/* Op1 = 3, CRn = 14, CRm = 0 */
609 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
610 };
611 
612 static int search_cmp_ftr_reg(const void *id, const void *regp)
613 {
614 	return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
615 }
616 
617 /*
618  * get_arm64_ftr_reg_nowarn - Looks up a feature register entry using
619  * its sys_reg() encoding. With the array arm64_ftr_regs sorted in the
620  * ascending order of sys_id, we use binary search to find a matching
621  * entry.
622  *
623  * returns - Upon success,  matching ftr_reg entry for id.
624  *         - NULL on failure. It is upto the caller to decide
625  *	     the impact of a failure.
626  */
627 static struct arm64_ftr_reg *get_arm64_ftr_reg_nowarn(u32 sys_id)
628 {
629 	const struct __ftr_reg_entry *ret;
630 
631 	ret = bsearch((const void *)(unsigned long)sys_id,
632 			arm64_ftr_regs,
633 			ARRAY_SIZE(arm64_ftr_regs),
634 			sizeof(arm64_ftr_regs[0]),
635 			search_cmp_ftr_reg);
636 	if (ret)
637 		return ret->reg;
638 	return NULL;
639 }
640 
641 /*
642  * get_arm64_ftr_reg - Looks up a feature register entry using
643  * its sys_reg() encoding. This calls get_arm64_ftr_reg_nowarn().
644  *
645  * returns - Upon success,  matching ftr_reg entry for id.
646  *         - NULL on failure but with an WARN_ON().
647  */
648 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
649 {
650 	struct arm64_ftr_reg *reg;
651 
652 	reg = get_arm64_ftr_reg_nowarn(sys_id);
653 
654 	/*
655 	 * Requesting a non-existent register search is an error. Warn
656 	 * and let the caller handle it.
657 	 */
658 	WARN_ON(!reg);
659 	return reg;
660 }
661 
662 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
663 			       s64 ftr_val)
664 {
665 	u64 mask = arm64_ftr_mask(ftrp);
666 
667 	reg &= ~mask;
668 	reg |= (ftr_val << ftrp->shift) & mask;
669 	return reg;
670 }
671 
672 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
673 				s64 cur)
674 {
675 	s64 ret = 0;
676 
677 	switch (ftrp->type) {
678 	case FTR_EXACT:
679 		ret = ftrp->safe_val;
680 		break;
681 	case FTR_LOWER_SAFE:
682 		ret = new < cur ? new : cur;
683 		break;
684 	case FTR_HIGHER_OR_ZERO_SAFE:
685 		if (!cur || !new)
686 			break;
687 		/* Fallthrough */
688 	case FTR_HIGHER_SAFE:
689 		ret = new > cur ? new : cur;
690 		break;
691 	default:
692 		BUG();
693 	}
694 
695 	return ret;
696 }
697 
698 static void __init sort_ftr_regs(void)
699 {
700 	int i;
701 
702 	/* Check that the array is sorted so that we can do the binary search */
703 	for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++)
704 		BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
705 }
706 
707 /*
708  * Initialise the CPU feature register from Boot CPU values.
709  * Also initiliases the strict_mask for the register.
710  * Any bits that are not covered by an arm64_ftr_bits entry are considered
711  * RES0 for the system-wide value, and must strictly match.
712  */
713 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
714 {
715 	u64 val = 0;
716 	u64 strict_mask = ~0x0ULL;
717 	u64 user_mask = 0;
718 	u64 valid_mask = 0;
719 
720 	const struct arm64_ftr_bits *ftrp;
721 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
722 
723 	if (!reg)
724 		return;
725 
726 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
727 		u64 ftr_mask = arm64_ftr_mask(ftrp);
728 		s64 ftr_new = arm64_ftr_value(ftrp, new);
729 
730 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
731 
732 		valid_mask |= ftr_mask;
733 		if (!ftrp->strict)
734 			strict_mask &= ~ftr_mask;
735 		if (ftrp->visible)
736 			user_mask |= ftr_mask;
737 		else
738 			reg->user_val = arm64_ftr_set_value(ftrp,
739 							    reg->user_val,
740 							    ftrp->safe_val);
741 	}
742 
743 	val &= valid_mask;
744 
745 	reg->sys_val = val;
746 	reg->strict_mask = strict_mask;
747 	reg->user_mask = user_mask;
748 }
749 
750 extern const struct arm64_cpu_capabilities arm64_errata[];
751 static const struct arm64_cpu_capabilities arm64_features[];
752 
753 static void __init
754 init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
755 {
756 	for (; caps->matches; caps++) {
757 		if (WARN(caps->capability >= ARM64_NCAPS,
758 			"Invalid capability %d\n", caps->capability))
759 			continue;
760 		if (WARN(cpu_hwcaps_ptrs[caps->capability],
761 			"Duplicate entry for capability %d\n",
762 			caps->capability))
763 			continue;
764 		cpu_hwcaps_ptrs[caps->capability] = caps;
765 	}
766 }
767 
768 static void __init init_cpu_hwcaps_indirect_list(void)
769 {
770 	init_cpu_hwcaps_indirect_list_from_array(arm64_features);
771 	init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
772 }
773 
774 static void __init setup_boot_cpu_capabilities(void);
775 
776 void __init init_cpu_features(struct cpuinfo_arm64 *info)
777 {
778 	/* Before we start using the tables, make sure it is sorted */
779 	sort_ftr_regs();
780 
781 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
782 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
783 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
784 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
785 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
786 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
787 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
788 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
789 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
790 	init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
791 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
792 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
793 	init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
794 
795 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
796 		init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
797 		init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
798 		init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
799 		init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
800 		init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
801 		init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
802 		init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
803 		init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
804 		init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
805 		init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
806 		init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
807 		init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
808 		init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
809 		init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
810 		init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
811 		init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
812 		init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
813 		init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
814 		init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
815 		init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
816 		init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
817 	}
818 
819 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
820 		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
821 		sve_init_vq_map();
822 	}
823 
824 	/*
825 	 * Initialize the indirect array of CPU hwcaps capabilities pointers
826 	 * before we handle the boot CPU below.
827 	 */
828 	init_cpu_hwcaps_indirect_list();
829 
830 	/*
831 	 * Detect and enable early CPU capabilities based on the boot CPU,
832 	 * after we have initialised the CPU feature infrastructure.
833 	 */
834 	setup_boot_cpu_capabilities();
835 }
836 
837 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
838 {
839 	const struct arm64_ftr_bits *ftrp;
840 
841 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
842 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
843 		s64 ftr_new = arm64_ftr_value(ftrp, new);
844 
845 		if (ftr_cur == ftr_new)
846 			continue;
847 		/* Find a safe value */
848 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
849 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
850 	}
851 
852 }
853 
854 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
855 {
856 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
857 
858 	if (!regp)
859 		return 0;
860 
861 	update_cpu_ftr_reg(regp, val);
862 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
863 		return 0;
864 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
865 			regp->name, boot, cpu, val);
866 	return 1;
867 }
868 
869 static void relax_cpu_ftr_reg(u32 sys_id, int field)
870 {
871 	const struct arm64_ftr_bits *ftrp;
872 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
873 
874 	if (!regp)
875 		return;
876 
877 	for (ftrp = regp->ftr_bits; ftrp->width; ftrp++) {
878 		if (ftrp->shift == field) {
879 			regp->strict_mask &= ~arm64_ftr_mask(ftrp);
880 			break;
881 		}
882 	}
883 
884 	/* Bogus field? */
885 	WARN_ON(!ftrp->width);
886 }
887 
888 static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
889 				     struct cpuinfo_arm64 *boot)
890 {
891 	int taint = 0;
892 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
893 
894 	/*
895 	 * If we don't have AArch32 at all then skip the checks entirely
896 	 * as the register values may be UNKNOWN and we're not going to be
897 	 * using them for anything.
898 	 */
899 	if (!id_aa64pfr0_32bit_el0(pfr0))
900 		return taint;
901 
902 	/*
903 	 * If we don't have AArch32 at EL1, then relax the strictness of
904 	 * EL1-dependent register fields to avoid spurious sanity check fails.
905 	 */
906 	if (!id_aa64pfr0_32bit_el1(pfr0)) {
907 		relax_cpu_ftr_reg(SYS_ID_ISAR4_EL1, ID_ISAR4_SMC_SHIFT);
908 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRT_FRAC_SHIFT);
909 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SEC_FRAC_SHIFT);
910 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_VIRTUALIZATION_SHIFT);
911 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_SECURITY_SHIFT);
912 		relax_cpu_ftr_reg(SYS_ID_PFR1_EL1, ID_PFR1_PROGMOD_SHIFT);
913 	}
914 
915 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
916 				      info->reg_id_dfr0, boot->reg_id_dfr0);
917 	taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
918 				      info->reg_id_dfr1, boot->reg_id_dfr1);
919 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
920 				      info->reg_id_isar0, boot->reg_id_isar0);
921 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
922 				      info->reg_id_isar1, boot->reg_id_isar1);
923 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
924 				      info->reg_id_isar2, boot->reg_id_isar2);
925 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
926 				      info->reg_id_isar3, boot->reg_id_isar3);
927 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
928 				      info->reg_id_isar4, boot->reg_id_isar4);
929 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
930 				      info->reg_id_isar5, boot->reg_id_isar5);
931 	taint |= check_update_ftr_reg(SYS_ID_ISAR6_EL1, cpu,
932 				      info->reg_id_isar6, boot->reg_id_isar6);
933 
934 	/*
935 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
936 	 * ACTLR formats could differ across CPUs and therefore would have to
937 	 * be trapped for virtualization anyway.
938 	 */
939 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
940 				      info->reg_id_mmfr0, boot->reg_id_mmfr0);
941 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
942 				      info->reg_id_mmfr1, boot->reg_id_mmfr1);
943 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
944 				      info->reg_id_mmfr2, boot->reg_id_mmfr2);
945 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
946 				      info->reg_id_mmfr3, boot->reg_id_mmfr3);
947 	taint |= check_update_ftr_reg(SYS_ID_MMFR4_EL1, cpu,
948 				      info->reg_id_mmfr4, boot->reg_id_mmfr4);
949 	taint |= check_update_ftr_reg(SYS_ID_MMFR5_EL1, cpu,
950 				      info->reg_id_mmfr5, boot->reg_id_mmfr5);
951 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
952 				      info->reg_id_pfr0, boot->reg_id_pfr0);
953 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
954 				      info->reg_id_pfr1, boot->reg_id_pfr1);
955 	taint |= check_update_ftr_reg(SYS_ID_PFR2_EL1, cpu,
956 				      info->reg_id_pfr2, boot->reg_id_pfr2);
957 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
958 				      info->reg_mvfr0, boot->reg_mvfr0);
959 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
960 				      info->reg_mvfr1, boot->reg_mvfr1);
961 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
962 				      info->reg_mvfr2, boot->reg_mvfr2);
963 
964 	return taint;
965 }
966 
967 /*
968  * Update system wide CPU feature registers with the values from a
969  * non-boot CPU. Also performs SANITY checks to make sure that there
970  * aren't any insane variations from that of the boot CPU.
971  */
972 void update_cpu_features(int cpu,
973 			 struct cpuinfo_arm64 *info,
974 			 struct cpuinfo_arm64 *boot)
975 {
976 	int taint = 0;
977 
978 	/*
979 	 * The kernel can handle differing I-cache policies, but otherwise
980 	 * caches should look identical. Userspace JITs will make use of
981 	 * *minLine.
982 	 */
983 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
984 				      info->reg_ctr, boot->reg_ctr);
985 
986 	/*
987 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
988 	 * could result in too much or too little memory being zeroed if a
989 	 * process is preempted and migrated between CPUs.
990 	 */
991 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
992 				      info->reg_dczid, boot->reg_dczid);
993 
994 	/* If different, timekeeping will be broken (especially with KVM) */
995 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
996 				      info->reg_cntfrq, boot->reg_cntfrq);
997 
998 	/*
999 	 * The kernel uses self-hosted debug features and expects CPUs to
1000 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
1001 	 * and BRPs to be identical.
1002 	 * ID_AA64DFR1 is currently RES0.
1003 	 */
1004 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
1005 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
1006 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
1007 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
1008 	/*
1009 	 * Even in big.LITTLE, processors should be identical instruction-set
1010 	 * wise.
1011 	 */
1012 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
1013 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
1014 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
1015 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
1016 
1017 	/*
1018 	 * Differing PARange support is fine as long as all peripherals and
1019 	 * memory are mapped within the minimum PARange of all CPUs.
1020 	 * Linux should not care about secure memory.
1021 	 */
1022 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
1023 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
1024 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
1025 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
1026 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
1027 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
1028 
1029 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
1030 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
1031 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
1032 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
1033 
1034 	taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
1035 				      info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
1036 
1037 	if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
1038 		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
1039 					info->reg_zcr, boot->reg_zcr);
1040 
1041 		/* Probe vector lengths, unless we already gave up on SVE */
1042 		if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
1043 		    !system_capabilities_finalized())
1044 			sve_update_vq_map();
1045 	}
1046 
1047 	/*
1048 	 * This relies on a sanitised view of the AArch64 ID registers
1049 	 * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
1050 	 */
1051 	taint |= update_32bit_cpu_features(cpu, info, boot);
1052 
1053 	/*
1054 	 * Mismatched CPU features are a recipe for disaster. Don't even
1055 	 * pretend to support them.
1056 	 */
1057 	if (taint) {
1058 		pr_warn_once("Unsupported CPU feature variation detected.\n");
1059 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1060 	}
1061 }
1062 
1063 u64 read_sanitised_ftr_reg(u32 id)
1064 {
1065 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
1066 
1067 	if (!regp)
1068 		return 0;
1069 	return regp->sys_val;
1070 }
1071 
1072 #define read_sysreg_case(r)	\
1073 	case r:		return read_sysreg_s(r)
1074 
1075 /*
1076  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
1077  * Read the system register on the current CPU
1078  */
1079 static u64 __read_sysreg_by_encoding(u32 sys_id)
1080 {
1081 	switch (sys_id) {
1082 	read_sysreg_case(SYS_ID_PFR0_EL1);
1083 	read_sysreg_case(SYS_ID_PFR1_EL1);
1084 	read_sysreg_case(SYS_ID_PFR2_EL1);
1085 	read_sysreg_case(SYS_ID_DFR0_EL1);
1086 	read_sysreg_case(SYS_ID_DFR1_EL1);
1087 	read_sysreg_case(SYS_ID_MMFR0_EL1);
1088 	read_sysreg_case(SYS_ID_MMFR1_EL1);
1089 	read_sysreg_case(SYS_ID_MMFR2_EL1);
1090 	read_sysreg_case(SYS_ID_MMFR3_EL1);
1091 	read_sysreg_case(SYS_ID_MMFR4_EL1);
1092 	read_sysreg_case(SYS_ID_MMFR5_EL1);
1093 	read_sysreg_case(SYS_ID_ISAR0_EL1);
1094 	read_sysreg_case(SYS_ID_ISAR1_EL1);
1095 	read_sysreg_case(SYS_ID_ISAR2_EL1);
1096 	read_sysreg_case(SYS_ID_ISAR3_EL1);
1097 	read_sysreg_case(SYS_ID_ISAR4_EL1);
1098 	read_sysreg_case(SYS_ID_ISAR5_EL1);
1099 	read_sysreg_case(SYS_ID_ISAR6_EL1);
1100 	read_sysreg_case(SYS_MVFR0_EL1);
1101 	read_sysreg_case(SYS_MVFR1_EL1);
1102 	read_sysreg_case(SYS_MVFR2_EL1);
1103 
1104 	read_sysreg_case(SYS_ID_AA64PFR0_EL1);
1105 	read_sysreg_case(SYS_ID_AA64PFR1_EL1);
1106 	read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
1107 	read_sysreg_case(SYS_ID_AA64DFR0_EL1);
1108 	read_sysreg_case(SYS_ID_AA64DFR1_EL1);
1109 	read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
1110 	read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
1111 	read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
1112 	read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
1113 	read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
1114 
1115 	read_sysreg_case(SYS_CNTFRQ_EL0);
1116 	read_sysreg_case(SYS_CTR_EL0);
1117 	read_sysreg_case(SYS_DCZID_EL0);
1118 
1119 	default:
1120 		BUG();
1121 		return 0;
1122 	}
1123 }
1124 
1125 #include <linux/irqchip/arm-gic-v3.h>
1126 
1127 static bool
1128 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
1129 {
1130 	int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
1131 
1132 	return val >= entry->min_field_value;
1133 }
1134 
1135 static bool
1136 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
1137 {
1138 	u64 val;
1139 
1140 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
1141 	if (scope == SCOPE_SYSTEM)
1142 		val = read_sanitised_ftr_reg(entry->sys_reg);
1143 	else
1144 		val = __read_sysreg_by_encoding(entry->sys_reg);
1145 
1146 	return feature_matches(val, entry);
1147 }
1148 
1149 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
1150 {
1151 	bool has_sre;
1152 
1153 	if (!has_cpuid_feature(entry, scope))
1154 		return false;
1155 
1156 	has_sre = gic_enable_sre();
1157 	if (!has_sre)
1158 		pr_warn_once("%s present but disabled by higher exception level\n",
1159 			     entry->desc);
1160 
1161 	return has_sre;
1162 }
1163 
1164 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
1165 {
1166 	u32 midr = read_cpuid_id();
1167 
1168 	/* Cavium ThunderX pass 1.x and 2.x */
1169 	return midr_is_cpu_model_range(midr, MIDR_THUNDERX,
1170 		MIDR_CPU_VAR_REV(0, 0),
1171 		MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
1172 }
1173 
1174 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
1175 {
1176 	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1177 
1178 	return cpuid_feature_extract_signed_field(pfr0,
1179 					ID_AA64PFR0_FP_SHIFT) < 0;
1180 }
1181 
1182 static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
1183 			  int scope)
1184 {
1185 	u64 ctr;
1186 
1187 	if (scope == SCOPE_SYSTEM)
1188 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1189 	else
1190 		ctr = read_cpuid_effective_cachetype();
1191 
1192 	return ctr & BIT(CTR_IDC_SHIFT);
1193 }
1194 
1195 static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
1196 {
1197 	/*
1198 	 * If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
1199 	 * CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
1200 	 * to the CTR_EL0 on this CPU and emulate it with the real/safe
1201 	 * value.
1202 	 */
1203 	if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
1204 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
1205 }
1206 
1207 static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
1208 			  int scope)
1209 {
1210 	u64 ctr;
1211 
1212 	if (scope == SCOPE_SYSTEM)
1213 		ctr = arm64_ftr_reg_ctrel0.sys_val;
1214 	else
1215 		ctr = read_cpuid_cachetype();
1216 
1217 	return ctr & BIT(CTR_DIC_SHIFT);
1218 }
1219 
1220 static bool __maybe_unused
1221 has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
1222 {
1223 	/*
1224 	 * Kdump isn't guaranteed to power-off all secondary CPUs, CNP
1225 	 * may share TLB entries with a CPU stuck in the crashed
1226 	 * kernel.
1227 	 */
1228 	 if (is_kdump_kernel())
1229 		return false;
1230 
1231 	return has_cpuid_feature(entry, scope);
1232 }
1233 
1234 /*
1235  * This check is triggered during the early boot before the cpufeature
1236  * is initialised. Checking the status on the local CPU allows the boot
1237  * CPU to detect the need for non-global mappings and thus avoiding a
1238  * pagetable re-write after all the CPUs are booted. This check will be
1239  * anyway run on individual CPUs, allowing us to get the consistent
1240  * state once the SMP CPUs are up and thus make the switch to non-global
1241  * mappings if required.
1242  */
1243 bool kaslr_requires_kpti(void)
1244 {
1245 	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
1246 		return false;
1247 
1248 	/*
1249 	 * E0PD does a similar job to KPTI so can be used instead
1250 	 * where available.
1251 	 */
1252 	if (IS_ENABLED(CONFIG_ARM64_E0PD)) {
1253 		u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
1254 		if (cpuid_feature_extract_unsigned_field(mmfr2,
1255 						ID_AA64MMFR2_E0PD_SHIFT))
1256 			return false;
1257 	}
1258 
1259 	/*
1260 	 * Systems affected by Cavium erratum 24756 are incompatible
1261 	 * with KPTI.
1262 	 */
1263 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
1264 		extern const struct midr_range cavium_erratum_27456_cpus[];
1265 
1266 		if (is_midr_in_range_list(read_cpuid_id(),
1267 					  cavium_erratum_27456_cpus))
1268 			return false;
1269 	}
1270 
1271 	return kaslr_offset() > 0;
1272 }
1273 
1274 static bool __meltdown_safe = true;
1275 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
1276 
1277 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
1278 				int scope)
1279 {
1280 	/* List of CPUs that are not vulnerable and don't need KPTI */
1281 	static const struct midr_range kpti_safe_list[] = {
1282 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
1283 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
1284 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
1285 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
1286 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
1287 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
1288 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
1289 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
1290 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
1291 		MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
1292 		MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
1293 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
1294 		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
1295 		{ /* sentinel */ }
1296 	};
1297 	char const *str = "kpti command line option";
1298 	bool meltdown_safe;
1299 
1300 	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
1301 
1302 	/* Defer to CPU feature registers */
1303 	if (has_cpuid_feature(entry, scope))
1304 		meltdown_safe = true;
1305 
1306 	if (!meltdown_safe)
1307 		__meltdown_safe = false;
1308 
1309 	/*
1310 	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
1311 	 * ThunderX leads to apparent I-cache corruption of kernel text, which
1312 	 * ends as well as you might imagine. Don't even try.
1313 	 */
1314 	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
1315 		str = "ARM64_WORKAROUND_CAVIUM_27456";
1316 		__kpti_forced = -1;
1317 	}
1318 
1319 	/* Useful for KASLR robustness */
1320 	if (kaslr_requires_kpti()) {
1321 		if (!__kpti_forced) {
1322 			str = "KASLR";
1323 			__kpti_forced = 1;
1324 		}
1325 	}
1326 
1327 	if (cpu_mitigations_off() && !__kpti_forced) {
1328 		str = "mitigations=off";
1329 		__kpti_forced = -1;
1330 	}
1331 
1332 	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
1333 		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
1334 		return false;
1335 	}
1336 
1337 	/* Forced? */
1338 	if (__kpti_forced) {
1339 		pr_info_once("kernel page table isolation forced %s by %s\n",
1340 			     __kpti_forced > 0 ? "ON" : "OFF", str);
1341 		return __kpti_forced > 0;
1342 	}
1343 
1344 	return !meltdown_safe;
1345 }
1346 
1347 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1348 static void
1349 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1350 {
1351 	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
1352 	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
1353 	kpti_remap_fn *remap_fn;
1354 
1355 	int cpu = smp_processor_id();
1356 
1357 	/*
1358 	 * We don't need to rewrite the page-tables if either we've done
1359 	 * it already or we have KASLR enabled and therefore have not
1360 	 * created any global mappings at all.
1361 	 */
1362 	if (arm64_use_ng_mappings)
1363 		return;
1364 
1365 	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
1366 
1367 	cpu_install_idmap();
1368 	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
1369 	cpu_uninstall_idmap();
1370 
1371 	if (!cpu)
1372 		arm64_use_ng_mappings = true;
1373 
1374 	return;
1375 }
1376 #else
1377 static void
1378 kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
1379 {
1380 }
1381 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
1382 
1383 static int __init parse_kpti(char *str)
1384 {
1385 	bool enabled;
1386 	int ret = strtobool(str, &enabled);
1387 
1388 	if (ret)
1389 		return ret;
1390 
1391 	__kpti_forced = enabled ? 1 : -1;
1392 	return 0;
1393 }
1394 early_param("kpti", parse_kpti);
1395 
1396 #ifdef CONFIG_ARM64_HW_AFDBM
1397 static inline void __cpu_enable_hw_dbm(void)
1398 {
1399 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
1400 
1401 	write_sysreg(tcr, tcr_el1);
1402 	isb();
1403 }
1404 
1405 static bool cpu_has_broken_dbm(void)
1406 {
1407 	/* List of CPUs which have broken DBM support. */
1408 	static const struct midr_range cpus[] = {
1409 #ifdef CONFIG_ARM64_ERRATUM_1024718
1410 		MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0),  // A55 r0p0 -r1p0
1411 #endif
1412 		{},
1413 	};
1414 
1415 	return is_midr_in_range_list(read_cpuid_id(), cpus);
1416 }
1417 
1418 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
1419 {
1420 	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
1421 	       !cpu_has_broken_dbm();
1422 }
1423 
1424 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
1425 {
1426 	if (cpu_can_use_dbm(cap))
1427 		__cpu_enable_hw_dbm();
1428 }
1429 
1430 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
1431 		       int __unused)
1432 {
1433 	static bool detected = false;
1434 	/*
1435 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
1436 	 * run a mix of CPUs with and without the feature. So, we
1437 	 * unconditionally enable the capability to allow any late CPU
1438 	 * to use the feature. We only enable the control bits on the
1439 	 * CPU, if it actually supports.
1440 	 *
1441 	 * We have to make sure we print the "feature" detection only
1442 	 * when at least one CPU actually uses it. So check if this CPU
1443 	 * can actually use it and print the message exactly once.
1444 	 *
1445 	 * This is safe as all CPUs (including secondary CPUs - due to the
1446 	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
1447 	 * goes through the "matches" check exactly once. Also if a CPU
1448 	 * matches the criteria, it is guaranteed that the CPU will turn
1449 	 * the DBM on, as the capability is unconditionally enabled.
1450 	 */
1451 	if (!detected && cpu_can_use_dbm(cap)) {
1452 		detected = true;
1453 		pr_info("detected: Hardware dirty bit management\n");
1454 	}
1455 
1456 	return true;
1457 }
1458 
1459 #endif
1460 
1461 #ifdef CONFIG_ARM64_AMU_EXTN
1462 
1463 /*
1464  * The "amu_cpus" cpumask only signals that the CPU implementation for the
1465  * flagged CPUs supports the Activity Monitors Unit (AMU) but does not provide
1466  * information regarding all the events that it supports. When a CPU bit is
1467  * set in the cpumask, the user of this feature can only rely on the presence
1468  * of the 4 fixed counters for that CPU. But this does not guarantee that the
1469  * counters are enabled or access to these counters is enabled by code
1470  * executed at higher exception levels (firmware).
1471  */
1472 static struct cpumask amu_cpus __read_mostly;
1473 
1474 bool cpu_has_amu_feat(int cpu)
1475 {
1476 	return cpumask_test_cpu(cpu, &amu_cpus);
1477 }
1478 
1479 /* Initialize the use of AMU counters for frequency invariance */
1480 extern void init_cpu_freq_invariance_counters(void);
1481 
1482 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
1483 {
1484 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
1485 		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
1486 			smp_processor_id());
1487 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
1488 		init_cpu_freq_invariance_counters();
1489 	}
1490 }
1491 
1492 static bool has_amu(const struct arm64_cpu_capabilities *cap,
1493 		    int __unused)
1494 {
1495 	/*
1496 	 * The AMU extension is a non-conflicting feature: the kernel can
1497 	 * safely run a mix of CPUs with and without support for the
1498 	 * activity monitors extension. Therefore, unconditionally enable
1499 	 * the capability to allow any late CPU to use the feature.
1500 	 *
1501 	 * With this feature unconditionally enabled, the cpu_enable
1502 	 * function will be called for all CPUs that match the criteria,
1503 	 * including secondary and hotplugged, marking this feature as
1504 	 * present on that respective CPU. The enable function will also
1505 	 * print a detection message.
1506 	 */
1507 
1508 	return true;
1509 }
1510 #endif
1511 
1512 #ifdef CONFIG_ARM64_VHE
1513 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
1514 {
1515 	return is_kernel_in_hyp_mode();
1516 }
1517 
1518 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
1519 {
1520 	/*
1521 	 * Copy register values that aren't redirected by hardware.
1522 	 *
1523 	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
1524 	 * this value to tpidr_el2 before we patch the code. Once we've done
1525 	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
1526 	 * do anything here.
1527 	 */
1528 	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
1529 		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
1530 }
1531 #endif
1532 
1533 static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
1534 {
1535 	u64 val = read_sysreg_s(SYS_CLIDR_EL1);
1536 
1537 	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
1538 	WARN_ON(val & (7 << 27 | 7 << 21));
1539 }
1540 
1541 #ifdef CONFIG_ARM64_SSBD
1542 static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
1543 {
1544 	if (user_mode(regs))
1545 		return 1;
1546 
1547 	if (instr & BIT(PSTATE_Imm_shift))
1548 		regs->pstate |= PSR_SSBS_BIT;
1549 	else
1550 		regs->pstate &= ~PSR_SSBS_BIT;
1551 
1552 	arm64_skip_faulting_instruction(regs, 4);
1553 	return 0;
1554 }
1555 
1556 static struct undef_hook ssbs_emulation_hook = {
1557 	.instr_mask	= ~(1U << PSTATE_Imm_shift),
1558 	.instr_val	= 0xd500401f | PSTATE_SSBS,
1559 	.fn		= ssbs_emulation_handler,
1560 };
1561 
1562 static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
1563 {
1564 	static bool undef_hook_registered = false;
1565 	static DEFINE_RAW_SPINLOCK(hook_lock);
1566 
1567 	raw_spin_lock(&hook_lock);
1568 	if (!undef_hook_registered) {
1569 		register_undef_hook(&ssbs_emulation_hook);
1570 		undef_hook_registered = true;
1571 	}
1572 	raw_spin_unlock(&hook_lock);
1573 
1574 	if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
1575 		sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
1576 		arm64_set_ssbd_mitigation(false);
1577 	} else {
1578 		arm64_set_ssbd_mitigation(true);
1579 	}
1580 }
1581 #endif /* CONFIG_ARM64_SSBD */
1582 
1583 #ifdef CONFIG_ARM64_PAN
1584 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
1585 {
1586 	/*
1587 	 * We modify PSTATE. This won't work from irq context as the PSTATE
1588 	 * is discarded once we return from the exception.
1589 	 */
1590 	WARN_ON_ONCE(in_interrupt());
1591 
1592 	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
1593 	asm(SET_PSTATE_PAN(1));
1594 }
1595 #endif /* CONFIG_ARM64_PAN */
1596 
1597 #ifdef CONFIG_ARM64_RAS_EXTN
1598 static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
1599 {
1600 	/* Firmware may have left a deferred SError in this register. */
1601 	write_sysreg_s(0, SYS_DISR_EL1);
1602 }
1603 #endif /* CONFIG_ARM64_RAS_EXTN */
1604 
1605 #ifdef CONFIG_ARM64_PTR_AUTH
1606 static bool has_address_auth(const struct arm64_cpu_capabilities *entry,
1607 			     int __unused)
1608 {
1609 	return __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_ARCH) ||
1610 	       __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_IMP_DEF);
1611 }
1612 
1613 static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
1614 			     int __unused)
1615 {
1616 	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
1617 	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
1618 }
1619 #endif /* CONFIG_ARM64_PTR_AUTH */
1620 
1621 #ifdef CONFIG_ARM64_E0PD
1622 static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
1623 {
1624 	if (this_cpu_has_cap(ARM64_HAS_E0PD))
1625 		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
1626 }
1627 #endif /* CONFIG_ARM64_E0PD */
1628 
1629 #ifdef CONFIG_ARM64_PSEUDO_NMI
1630 static bool enable_pseudo_nmi;
1631 
1632 static int __init early_enable_pseudo_nmi(char *p)
1633 {
1634 	return strtobool(p, &enable_pseudo_nmi);
1635 }
1636 early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
1637 
1638 static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
1639 				   int scope)
1640 {
1641 	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
1642 }
1643 #endif
1644 
1645 #ifdef CONFIG_ARM64_BTI
1646 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
1647 {
1648 	/*
1649 	 * Use of X16/X17 for tail-calls and trampolines that jump to
1650 	 * function entry points using BR is a requirement for
1651 	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
1652 	 * So, be strict and forbid other BRs using other registers to
1653 	 * jump onto a PACIxSP instruction:
1654 	 */
1655 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
1656 	isb();
1657 }
1658 #endif /* CONFIG_ARM64_BTI */
1659 
1660 /* Internal helper functions to match cpu capability type */
1661 static bool
1662 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
1663 {
1664 	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
1665 }
1666 
1667 static bool
1668 cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
1669 {
1670 	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
1671 }
1672 
1673 static bool
1674 cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
1675 {
1676 	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
1677 }
1678 
1679 static const struct arm64_cpu_capabilities arm64_features[] = {
1680 	{
1681 		.desc = "GIC system register CPU interface",
1682 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
1683 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1684 		.matches = has_useable_gicv3_cpuif,
1685 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1686 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
1687 		.sign = FTR_UNSIGNED,
1688 		.min_field_value = 1,
1689 	},
1690 #ifdef CONFIG_ARM64_PAN
1691 	{
1692 		.desc = "Privileged Access Never",
1693 		.capability = ARM64_HAS_PAN,
1694 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1695 		.matches = has_cpuid_feature,
1696 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1697 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
1698 		.sign = FTR_UNSIGNED,
1699 		.min_field_value = 1,
1700 		.cpu_enable = cpu_enable_pan,
1701 	},
1702 #endif /* CONFIG_ARM64_PAN */
1703 #ifdef CONFIG_ARM64_LSE_ATOMICS
1704 	{
1705 		.desc = "LSE atomic instructions",
1706 		.capability = ARM64_HAS_LSE_ATOMICS,
1707 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1708 		.matches = has_cpuid_feature,
1709 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1710 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
1711 		.sign = FTR_UNSIGNED,
1712 		.min_field_value = 2,
1713 	},
1714 #endif /* CONFIG_ARM64_LSE_ATOMICS */
1715 	{
1716 		.desc = "Software prefetching using PRFM",
1717 		.capability = ARM64_HAS_NO_HW_PREFETCH,
1718 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1719 		.matches = has_no_hw_prefetch,
1720 	},
1721 #ifdef CONFIG_ARM64_UAO
1722 	{
1723 		.desc = "User Access Override",
1724 		.capability = ARM64_HAS_UAO,
1725 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1726 		.matches = has_cpuid_feature,
1727 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1728 		.field_pos = ID_AA64MMFR2_UAO_SHIFT,
1729 		.min_field_value = 1,
1730 		/*
1731 		 * We rely on stop_machine() calling uao_thread_switch() to set
1732 		 * UAO immediately after patching.
1733 		 */
1734 	},
1735 #endif /* CONFIG_ARM64_UAO */
1736 #ifdef CONFIG_ARM64_PAN
1737 	{
1738 		.capability = ARM64_ALT_PAN_NOT_UAO,
1739 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1740 		.matches = cpufeature_pan_not_uao,
1741 	},
1742 #endif /* CONFIG_ARM64_PAN */
1743 #ifdef CONFIG_ARM64_VHE
1744 	{
1745 		.desc = "Virtualization Host Extensions",
1746 		.capability = ARM64_HAS_VIRT_HOST_EXTN,
1747 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
1748 		.matches = runs_at_el2,
1749 		.cpu_enable = cpu_copy_el2regs,
1750 	},
1751 #endif	/* CONFIG_ARM64_VHE */
1752 	{
1753 		.desc = "32-bit EL0 Support",
1754 		.capability = ARM64_HAS_32BIT_EL0,
1755 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1756 		.matches = has_cpuid_feature,
1757 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1758 		.sign = FTR_UNSIGNED,
1759 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
1760 		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1761 	},
1762 #ifdef CONFIG_KVM
1763 	{
1764 		.desc = "32-bit EL1 Support",
1765 		.capability = ARM64_HAS_32BIT_EL1,
1766 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1767 		.matches = has_cpuid_feature,
1768 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1769 		.sign = FTR_UNSIGNED,
1770 		.field_pos = ID_AA64PFR0_EL1_SHIFT,
1771 		.min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
1772 	},
1773 #endif
1774 	{
1775 		.desc = "Kernel page table isolation (KPTI)",
1776 		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
1777 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1778 		/*
1779 		 * The ID feature fields below are used to indicate that
1780 		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
1781 		 * more details.
1782 		 */
1783 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1784 		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
1785 		.min_field_value = 1,
1786 		.matches = unmap_kernel_at_el0,
1787 		.cpu_enable = kpti_install_ng_mappings,
1788 	},
1789 	{
1790 		/* FP/SIMD is not implemented */
1791 		.capability = ARM64_HAS_NO_FPSIMD,
1792 		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
1793 		.min_field_value = 0,
1794 		.matches = has_no_fpsimd,
1795 	},
1796 #ifdef CONFIG_ARM64_PMEM
1797 	{
1798 		.desc = "Data cache clean to Point of Persistence",
1799 		.capability = ARM64_HAS_DCPOP,
1800 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1801 		.matches = has_cpuid_feature,
1802 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1803 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1804 		.min_field_value = 1,
1805 	},
1806 	{
1807 		.desc = "Data cache clean to Point of Deep Persistence",
1808 		.capability = ARM64_HAS_DCPODP,
1809 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1810 		.matches = has_cpuid_feature,
1811 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1812 		.sign = FTR_UNSIGNED,
1813 		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
1814 		.min_field_value = 2,
1815 	},
1816 #endif
1817 #ifdef CONFIG_ARM64_SVE
1818 	{
1819 		.desc = "Scalable Vector Extension",
1820 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1821 		.capability = ARM64_SVE,
1822 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1823 		.sign = FTR_UNSIGNED,
1824 		.field_pos = ID_AA64PFR0_SVE_SHIFT,
1825 		.min_field_value = ID_AA64PFR0_SVE,
1826 		.matches = has_cpuid_feature,
1827 		.cpu_enable = sve_kernel_enable,
1828 	},
1829 #endif /* CONFIG_ARM64_SVE */
1830 #ifdef CONFIG_ARM64_RAS_EXTN
1831 	{
1832 		.desc = "RAS Extension Support",
1833 		.capability = ARM64_HAS_RAS_EXTN,
1834 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1835 		.matches = has_cpuid_feature,
1836 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1837 		.sign = FTR_UNSIGNED,
1838 		.field_pos = ID_AA64PFR0_RAS_SHIFT,
1839 		.min_field_value = ID_AA64PFR0_RAS_V1,
1840 		.cpu_enable = cpu_clear_disr,
1841 	},
1842 #endif /* CONFIG_ARM64_RAS_EXTN */
1843 #ifdef CONFIG_ARM64_AMU_EXTN
1844 	{
1845 		/*
1846 		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
1847 		 * Therefore, don't provide .desc as we don't want the detection
1848 		 * message to be shown until at least one CPU is detected to
1849 		 * support the feature.
1850 		 */
1851 		.capability = ARM64_HAS_AMU_EXTN,
1852 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1853 		.matches = has_amu,
1854 		.sys_reg = SYS_ID_AA64PFR0_EL1,
1855 		.sign = FTR_UNSIGNED,
1856 		.field_pos = ID_AA64PFR0_AMU_SHIFT,
1857 		.min_field_value = ID_AA64PFR0_AMU,
1858 		.cpu_enable = cpu_amu_enable,
1859 	},
1860 #endif /* CONFIG_ARM64_AMU_EXTN */
1861 	{
1862 		.desc = "Data cache clean to the PoU not required for I/D coherence",
1863 		.capability = ARM64_HAS_CACHE_IDC,
1864 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1865 		.matches = has_cache_idc,
1866 		.cpu_enable = cpu_emulate_effective_ctr,
1867 	},
1868 	{
1869 		.desc = "Instruction cache invalidation not required for I/D coherence",
1870 		.capability = ARM64_HAS_CACHE_DIC,
1871 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1872 		.matches = has_cache_dic,
1873 	},
1874 	{
1875 		.desc = "Stage-2 Force Write-Back",
1876 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1877 		.capability = ARM64_HAS_STAGE2_FWB,
1878 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1879 		.sign = FTR_UNSIGNED,
1880 		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
1881 		.min_field_value = 1,
1882 		.matches = has_cpuid_feature,
1883 		.cpu_enable = cpu_has_fwb,
1884 	},
1885 #ifdef CONFIG_ARM64_HW_AFDBM
1886 	{
1887 		/*
1888 		 * Since we turn this on always, we don't want the user to
1889 		 * think that the feature is available when it may not be.
1890 		 * So hide the description.
1891 		 *
1892 		 * .desc = "Hardware pagetable Dirty Bit Management",
1893 		 *
1894 		 */
1895 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1896 		.capability = ARM64_HW_DBM,
1897 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
1898 		.sign = FTR_UNSIGNED,
1899 		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
1900 		.min_field_value = 2,
1901 		.matches = has_hw_dbm,
1902 		.cpu_enable = cpu_enable_hw_dbm,
1903 	},
1904 #endif
1905 	{
1906 		.desc = "CRC32 instructions",
1907 		.capability = ARM64_HAS_CRC32,
1908 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1909 		.matches = has_cpuid_feature,
1910 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
1911 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
1912 		.min_field_value = 1,
1913 	},
1914 #ifdef CONFIG_ARM64_SSBD
1915 	{
1916 		.desc = "Speculative Store Bypassing Safe (SSBS)",
1917 		.capability = ARM64_SSBS,
1918 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
1919 		.matches = has_cpuid_feature,
1920 		.sys_reg = SYS_ID_AA64PFR1_EL1,
1921 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
1922 		.sign = FTR_UNSIGNED,
1923 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
1924 		.cpu_enable = cpu_enable_ssbs,
1925 	},
1926 #endif
1927 #ifdef CONFIG_ARM64_CNP
1928 	{
1929 		.desc = "Common not Private translations",
1930 		.capability = ARM64_HAS_CNP,
1931 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1932 		.matches = has_useable_cnp,
1933 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
1934 		.sign = FTR_UNSIGNED,
1935 		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
1936 		.min_field_value = 1,
1937 		.cpu_enable = cpu_enable_cnp,
1938 	},
1939 #endif
1940 	{
1941 		.desc = "Speculation barrier (SB)",
1942 		.capability = ARM64_HAS_SB,
1943 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1944 		.matches = has_cpuid_feature,
1945 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1946 		.field_pos = ID_AA64ISAR1_SB_SHIFT,
1947 		.sign = FTR_UNSIGNED,
1948 		.min_field_value = 1,
1949 	},
1950 #ifdef CONFIG_ARM64_PTR_AUTH
1951 	{
1952 		.desc = "Address authentication (architected algorithm)",
1953 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
1954 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
1955 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1956 		.sign = FTR_UNSIGNED,
1957 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
1958 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
1959 		.matches = has_cpuid_feature,
1960 	},
1961 	{
1962 		.desc = "Address authentication (IMP DEF algorithm)",
1963 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
1964 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
1965 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1966 		.sign = FTR_UNSIGNED,
1967 		.field_pos = ID_AA64ISAR1_API_SHIFT,
1968 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
1969 		.matches = has_cpuid_feature,
1970 	},
1971 	{
1972 		.capability = ARM64_HAS_ADDRESS_AUTH,
1973 		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
1974 		.matches = has_address_auth,
1975 	},
1976 	{
1977 		.desc = "Generic authentication (architected algorithm)",
1978 		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
1979 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1980 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1981 		.sign = FTR_UNSIGNED,
1982 		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
1983 		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
1984 		.matches = has_cpuid_feature,
1985 	},
1986 	{
1987 		.desc = "Generic authentication (IMP DEF algorithm)",
1988 		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
1989 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1990 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
1991 		.sign = FTR_UNSIGNED,
1992 		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
1993 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
1994 		.matches = has_cpuid_feature,
1995 	},
1996 	{
1997 		.capability = ARM64_HAS_GENERIC_AUTH,
1998 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
1999 		.matches = has_generic_auth,
2000 	},
2001 #endif /* CONFIG_ARM64_PTR_AUTH */
2002 #ifdef CONFIG_ARM64_PSEUDO_NMI
2003 	{
2004 		/*
2005 		 * Depends on having GICv3
2006 		 */
2007 		.desc = "IRQ priority masking",
2008 		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
2009 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2010 		.matches = can_use_gic_priorities,
2011 		.sys_reg = SYS_ID_AA64PFR0_EL1,
2012 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
2013 		.sign = FTR_UNSIGNED,
2014 		.min_field_value = 1,
2015 	},
2016 #endif
2017 #ifdef CONFIG_ARM64_E0PD
2018 	{
2019 		.desc = "E0PD",
2020 		.capability = ARM64_HAS_E0PD,
2021 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2022 		.sys_reg = SYS_ID_AA64MMFR2_EL1,
2023 		.sign = FTR_UNSIGNED,
2024 		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
2025 		.matches = has_cpuid_feature,
2026 		.min_field_value = 1,
2027 		.cpu_enable = cpu_enable_e0pd,
2028 	},
2029 #endif
2030 #ifdef CONFIG_ARCH_RANDOM
2031 	{
2032 		.desc = "Random Number Generator",
2033 		.capability = ARM64_HAS_RNG,
2034 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2035 		.matches = has_cpuid_feature,
2036 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
2037 		.field_pos = ID_AA64ISAR0_RNDR_SHIFT,
2038 		.sign = FTR_UNSIGNED,
2039 		.min_field_value = 1,
2040 	},
2041 #endif
2042 #ifdef CONFIG_ARM64_BTI
2043 	{
2044 		.desc = "Branch Target Identification",
2045 		.capability = ARM64_BTI,
2046 #ifdef CONFIG_ARM64_BTI_KERNEL
2047 		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
2048 #else
2049 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
2050 #endif
2051 		.matches = has_cpuid_feature,
2052 		.cpu_enable = bti_enable,
2053 		.sys_reg = SYS_ID_AA64PFR1_EL1,
2054 		.field_pos = ID_AA64PFR1_BT_SHIFT,
2055 		.min_field_value = ID_AA64PFR1_BT_BTI,
2056 		.sign = FTR_UNSIGNED,
2057 	},
2058 #endif
2059 	{},
2060 };
2061 
2062 #define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
2063 		.matches = has_cpuid_feature,					\
2064 		.sys_reg = reg,							\
2065 		.field_pos = field,						\
2066 		.sign = s,							\
2067 		.min_field_value = min_value,
2068 
2069 #define __HWCAP_CAP(name, cap_type, cap)					\
2070 		.desc = name,							\
2071 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
2072 		.hwcap_type = cap_type,						\
2073 		.hwcap = cap,							\
2074 
2075 #define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
2076 	{									\
2077 		__HWCAP_CAP(#cap, cap_type, cap)				\
2078 		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
2079 	}
2080 
2081 #define HWCAP_MULTI_CAP(list, cap_type, cap)					\
2082 	{									\
2083 		__HWCAP_CAP(#cap, cap_type, cap)				\
2084 		.matches = cpucap_multi_entry_cap_matches,			\
2085 		.match_list = list,						\
2086 	}
2087 
2088 #define HWCAP_CAP_MATCH(match, cap_type, cap)					\
2089 	{									\
2090 		__HWCAP_CAP(#cap, cap_type, cap)				\
2091 		.matches = match,						\
2092 	}
2093 
2094 #ifdef CONFIG_ARM64_PTR_AUTH
2095 static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
2096 	{
2097 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
2098 				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
2099 	},
2100 	{
2101 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
2102 				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
2103 	},
2104 	{},
2105 };
2106 
2107 static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
2108 	{
2109 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
2110 				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
2111 	},
2112 	{
2113 		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
2114 				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
2115 	},
2116 	{},
2117 };
2118 #endif
2119 
2120 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
2121 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
2122 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
2123 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
2124 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
2125 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
2126 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
2127 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
2128 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
2129 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
2130 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
2131 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
2132 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
2133 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
2134 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
2135 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
2136 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG),
2137 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
2138 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
2139 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
2140 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
2141 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
2142 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
2143 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
2144 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
2145 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
2146 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
2147 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
2148 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
2149 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
2150 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
2151 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
2152 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
2153 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
2154 #ifdef CONFIG_ARM64_SVE
2155 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
2156 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
2157 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
2158 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
2159 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
2160 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BF16_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BF16, CAP_HWCAP, KERNEL_HWCAP_SVEBF16),
2161 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
2162 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
2163 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
2164 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
2165 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
2166 #endif
2167 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
2168 #ifdef CONFIG_ARM64_BTI
2169 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
2170 #endif
2171 #ifdef CONFIG_ARM64_PTR_AUTH
2172 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
2173 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
2174 #endif
2175 	{},
2176 };
2177 
2178 #ifdef CONFIG_COMPAT
2179 static bool compat_has_neon(const struct arm64_cpu_capabilities *cap, int scope)
2180 {
2181 	/*
2182 	 * Check that all of MVFR1_EL1.{SIMDSP, SIMDInt, SIMDLS} are available,
2183 	 * in line with that of arm32 as in vfp_init(). We make sure that the
2184 	 * check is future proof, by making sure value is non-zero.
2185 	 */
2186 	u32 mvfr1;
2187 
2188 	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
2189 	if (scope == SCOPE_SYSTEM)
2190 		mvfr1 = read_sanitised_ftr_reg(SYS_MVFR1_EL1);
2191 	else
2192 		mvfr1 = read_sysreg_s(SYS_MVFR1_EL1);
2193 
2194 	return cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDSP_SHIFT) &&
2195 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDINT_SHIFT) &&
2196 		cpuid_feature_extract_unsigned_field(mvfr1, MVFR1_SIMDLS_SHIFT);
2197 }
2198 #endif
2199 
2200 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
2201 #ifdef CONFIG_COMPAT
2202 	HWCAP_CAP_MATCH(compat_has_neon, CAP_COMPAT_HWCAP, COMPAT_HWCAP_NEON),
2203 	HWCAP_CAP(SYS_MVFR1_EL1, MVFR1_SIMDFMAC_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv4),
2204 	/* Arm v8 mandates MVFR0.FPDP == {0, 2}. So, piggy back on this for the presence of VFP support */
2205 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFP),
2206 	HWCAP_CAP(SYS_MVFR0_EL1, MVFR0_FPDP_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP, COMPAT_HWCAP_VFPv3),
2207 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
2208 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
2209 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
2210 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
2211 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
2212 #endif
2213 	{},
2214 };
2215 
2216 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2217 {
2218 	switch (cap->hwcap_type) {
2219 	case CAP_HWCAP:
2220 		cpu_set_feature(cap->hwcap);
2221 		break;
2222 #ifdef CONFIG_COMPAT
2223 	case CAP_COMPAT_HWCAP:
2224 		compat_elf_hwcap |= (u32)cap->hwcap;
2225 		break;
2226 	case CAP_COMPAT_HWCAP2:
2227 		compat_elf_hwcap2 |= (u32)cap->hwcap;
2228 		break;
2229 #endif
2230 	default:
2231 		WARN_ON(1);
2232 		break;
2233 	}
2234 }
2235 
2236 /* Check if we have a particular HWCAP enabled */
2237 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
2238 {
2239 	bool rc;
2240 
2241 	switch (cap->hwcap_type) {
2242 	case CAP_HWCAP:
2243 		rc = cpu_have_feature(cap->hwcap);
2244 		break;
2245 #ifdef CONFIG_COMPAT
2246 	case CAP_COMPAT_HWCAP:
2247 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
2248 		break;
2249 	case CAP_COMPAT_HWCAP2:
2250 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
2251 		break;
2252 #endif
2253 	default:
2254 		WARN_ON(1);
2255 		rc = false;
2256 	}
2257 
2258 	return rc;
2259 }
2260 
2261 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
2262 {
2263 	/* We support emulation of accesses to CPU ID feature registers */
2264 	cpu_set_named_feature(CPUID);
2265 	for (; hwcaps->matches; hwcaps++)
2266 		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
2267 			cap_set_elf_hwcap(hwcaps);
2268 }
2269 
2270 static void update_cpu_capabilities(u16 scope_mask)
2271 {
2272 	int i;
2273 	const struct arm64_cpu_capabilities *caps;
2274 
2275 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2276 	for (i = 0; i < ARM64_NCAPS; i++) {
2277 		caps = cpu_hwcaps_ptrs[i];
2278 		if (!caps || !(caps->type & scope_mask) ||
2279 		    cpus_have_cap(caps->capability) ||
2280 		    !caps->matches(caps, cpucap_default_scope(caps)))
2281 			continue;
2282 
2283 		if (caps->desc)
2284 			pr_info("detected: %s\n", caps->desc);
2285 		cpus_set_cap(caps->capability);
2286 
2287 		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
2288 			set_bit(caps->capability, boot_capabilities);
2289 	}
2290 }
2291 
2292 /*
2293  * Enable all the available capabilities on this CPU. The capabilities
2294  * with BOOT_CPU scope are handled separately and hence skipped here.
2295  */
2296 static int cpu_enable_non_boot_scope_capabilities(void *__unused)
2297 {
2298 	int i;
2299 	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
2300 
2301 	for_each_available_cap(i) {
2302 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
2303 
2304 		if (WARN_ON(!cap))
2305 			continue;
2306 
2307 		if (!(cap->type & non_boot_scope))
2308 			continue;
2309 
2310 		if (cap->cpu_enable)
2311 			cap->cpu_enable(cap);
2312 	}
2313 	return 0;
2314 }
2315 
2316 /*
2317  * Run through the enabled capabilities and enable() it on all active
2318  * CPUs
2319  */
2320 static void __init enable_cpu_capabilities(u16 scope_mask)
2321 {
2322 	int i;
2323 	const struct arm64_cpu_capabilities *caps;
2324 	bool boot_scope;
2325 
2326 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2327 	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
2328 
2329 	for (i = 0; i < ARM64_NCAPS; i++) {
2330 		unsigned int num;
2331 
2332 		caps = cpu_hwcaps_ptrs[i];
2333 		if (!caps || !(caps->type & scope_mask))
2334 			continue;
2335 		num = caps->capability;
2336 		if (!cpus_have_cap(num))
2337 			continue;
2338 
2339 		/* Ensure cpus_have_const_cap(num) works */
2340 		static_branch_enable(&cpu_hwcap_keys[num]);
2341 
2342 		if (boot_scope && caps->cpu_enable)
2343 			/*
2344 			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
2345 			 * before any secondary CPU boots. Thus, each secondary
2346 			 * will enable the capability as appropriate via
2347 			 * check_local_cpu_capabilities(). The only exception is
2348 			 * the boot CPU, for which the capability must be
2349 			 * enabled here. This approach avoids costly
2350 			 * stop_machine() calls for this case.
2351 			 */
2352 			caps->cpu_enable(caps);
2353 	}
2354 
2355 	/*
2356 	 * For all non-boot scope capabilities, use stop_machine()
2357 	 * as it schedules the work allowing us to modify PSTATE,
2358 	 * instead of on_each_cpu() which uses an IPI, giving us a
2359 	 * PSTATE that disappears when we return.
2360 	 */
2361 	if (!boot_scope)
2362 		stop_machine(cpu_enable_non_boot_scope_capabilities,
2363 			     NULL, cpu_online_mask);
2364 }
2365 
2366 /*
2367  * Run through the list of capabilities to check for conflicts.
2368  * If the system has already detected a capability, take necessary
2369  * action on this CPU.
2370  */
2371 static void verify_local_cpu_caps(u16 scope_mask)
2372 {
2373 	int i;
2374 	bool cpu_has_cap, system_has_cap;
2375 	const struct arm64_cpu_capabilities *caps;
2376 
2377 	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
2378 
2379 	for (i = 0; i < ARM64_NCAPS; i++) {
2380 		caps = cpu_hwcaps_ptrs[i];
2381 		if (!caps || !(caps->type & scope_mask))
2382 			continue;
2383 
2384 		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
2385 		system_has_cap = cpus_have_cap(caps->capability);
2386 
2387 		if (system_has_cap) {
2388 			/*
2389 			 * Check if the new CPU misses an advertised feature,
2390 			 * which is not safe to miss.
2391 			 */
2392 			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
2393 				break;
2394 			/*
2395 			 * We have to issue cpu_enable() irrespective of
2396 			 * whether the CPU has it or not, as it is enabeld
2397 			 * system wide. It is upto the call back to take
2398 			 * appropriate action on this CPU.
2399 			 */
2400 			if (caps->cpu_enable)
2401 				caps->cpu_enable(caps);
2402 		} else {
2403 			/*
2404 			 * Check if the CPU has this capability if it isn't
2405 			 * safe to have when the system doesn't.
2406 			 */
2407 			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
2408 				break;
2409 		}
2410 	}
2411 
2412 	if (i < ARM64_NCAPS) {
2413 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
2414 			smp_processor_id(), caps->capability,
2415 			caps->desc, system_has_cap, cpu_has_cap);
2416 
2417 		if (cpucap_panic_on_conflict(caps))
2418 			cpu_panic_kernel();
2419 		else
2420 			cpu_die_early();
2421 	}
2422 }
2423 
2424 /*
2425  * Check for CPU features that are used in early boot
2426  * based on the Boot CPU value.
2427  */
2428 static void check_early_cpu_features(void)
2429 {
2430 	verify_cpu_asid_bits();
2431 
2432 	verify_local_cpu_caps(SCOPE_BOOT_CPU);
2433 }
2434 
2435 static void
2436 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
2437 {
2438 
2439 	for (; caps->matches; caps++)
2440 		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
2441 			pr_crit("CPU%d: missing HWCAP: %s\n",
2442 					smp_processor_id(), caps->desc);
2443 			cpu_die_early();
2444 		}
2445 }
2446 
2447 static void verify_sve_features(void)
2448 {
2449 	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
2450 	u64 zcr = read_zcr_features();
2451 
2452 	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
2453 	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
2454 
2455 	if (len < safe_len || sve_verify_vq_map()) {
2456 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
2457 			smp_processor_id());
2458 		cpu_die_early();
2459 	}
2460 
2461 	/* Add checks on other ZCR bits here if necessary */
2462 }
2463 
2464 static void verify_hyp_capabilities(void)
2465 {
2466 	u64 safe_mmfr1, mmfr0, mmfr1;
2467 	int parange, ipa_max;
2468 	unsigned int safe_vmid_bits, vmid_bits;
2469 
2470 	if (!IS_ENABLED(CONFIG_KVM) || !IS_ENABLED(CONFIG_KVM_ARM_HOST))
2471 		return;
2472 
2473 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
2474 	mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
2475 	mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
2476 
2477 	/* Verify VMID bits */
2478 	safe_vmid_bits = get_vmid_bits(safe_mmfr1);
2479 	vmid_bits = get_vmid_bits(mmfr1);
2480 	if (vmid_bits < safe_vmid_bits) {
2481 		pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
2482 		cpu_die_early();
2483 	}
2484 
2485 	/* Verify IPA range */
2486 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
2487 				ID_AA64MMFR0_PARANGE_SHIFT);
2488 	ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
2489 	if (ipa_max < get_kvm_ipa_limit()) {
2490 		pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
2491 		cpu_die_early();
2492 	}
2493 }
2494 
2495 /*
2496  * Run through the enabled system capabilities and enable() it on this CPU.
2497  * The capabilities were decided based on the available CPUs at the boot time.
2498  * Any new CPU should match the system wide status of the capability. If the
2499  * new CPU doesn't have a capability which the system now has enabled, we
2500  * cannot do anything to fix it up and could cause unexpected failures. So
2501  * we park the CPU.
2502  */
2503 static void verify_local_cpu_capabilities(void)
2504 {
2505 	/*
2506 	 * The capabilities with SCOPE_BOOT_CPU are checked from
2507 	 * check_early_cpu_features(), as they need to be verified
2508 	 * on all secondary CPUs.
2509 	 */
2510 	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2511 
2512 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
2513 
2514 	if (system_supports_32bit_el0())
2515 		verify_local_elf_hwcaps(compat_elf_hwcaps);
2516 
2517 	if (system_supports_sve())
2518 		verify_sve_features();
2519 
2520 	if (is_hyp_mode_available())
2521 		verify_hyp_capabilities();
2522 }
2523 
2524 void check_local_cpu_capabilities(void)
2525 {
2526 	/*
2527 	 * All secondary CPUs should conform to the early CPU features
2528 	 * in use by the kernel based on boot CPU.
2529 	 */
2530 	check_early_cpu_features();
2531 
2532 	/*
2533 	 * If we haven't finalised the system capabilities, this CPU gets
2534 	 * a chance to update the errata work arounds and local features.
2535 	 * Otherwise, this CPU should verify that it has all the system
2536 	 * advertised capabilities.
2537 	 */
2538 	if (!system_capabilities_finalized())
2539 		update_cpu_capabilities(SCOPE_LOCAL_CPU);
2540 	else
2541 		verify_local_cpu_capabilities();
2542 }
2543 
2544 static void __init setup_boot_cpu_capabilities(void)
2545 {
2546 	/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
2547 	update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
2548 	/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
2549 	enable_cpu_capabilities(SCOPE_BOOT_CPU);
2550 }
2551 
2552 bool this_cpu_has_cap(unsigned int n)
2553 {
2554 	if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
2555 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2556 
2557 		if (cap)
2558 			return cap->matches(cap, SCOPE_LOCAL_CPU);
2559 	}
2560 
2561 	return false;
2562 }
2563 
2564 /*
2565  * This helper function is used in a narrow window when,
2566  * - The system wide safe registers are set with all the SMP CPUs and,
2567  * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
2568  * In all other cases cpus_have_{const_}cap() should be used.
2569  */
2570 static bool __system_matches_cap(unsigned int n)
2571 {
2572 	if (n < ARM64_NCAPS) {
2573 		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
2574 
2575 		if (cap)
2576 			return cap->matches(cap, SCOPE_SYSTEM);
2577 	}
2578 	return false;
2579 }
2580 
2581 void cpu_set_feature(unsigned int num)
2582 {
2583 	WARN_ON(num >= MAX_CPU_FEATURES);
2584 	elf_hwcap |= BIT(num);
2585 }
2586 EXPORT_SYMBOL_GPL(cpu_set_feature);
2587 
2588 bool cpu_have_feature(unsigned int num)
2589 {
2590 	WARN_ON(num >= MAX_CPU_FEATURES);
2591 	return elf_hwcap & BIT(num);
2592 }
2593 EXPORT_SYMBOL_GPL(cpu_have_feature);
2594 
2595 unsigned long cpu_get_elf_hwcap(void)
2596 {
2597 	/*
2598 	 * We currently only populate the first 32 bits of AT_HWCAP. Please
2599 	 * note that for userspace compatibility we guarantee that bits 62
2600 	 * and 63 will always be returned as 0.
2601 	 */
2602 	return lower_32_bits(elf_hwcap);
2603 }
2604 
2605 unsigned long cpu_get_elf_hwcap2(void)
2606 {
2607 	return upper_32_bits(elf_hwcap);
2608 }
2609 
2610 static void __init setup_system_capabilities(void)
2611 {
2612 	/*
2613 	 * We have finalised the system-wide safe feature
2614 	 * registers, finalise the capabilities that depend
2615 	 * on it. Also enable all the available capabilities,
2616 	 * that are not enabled already.
2617 	 */
2618 	update_cpu_capabilities(SCOPE_SYSTEM);
2619 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
2620 }
2621 
2622 void __init setup_cpu_features(void)
2623 {
2624 	u32 cwg;
2625 
2626 	setup_system_capabilities();
2627 	setup_elf_hwcaps(arm64_elf_hwcaps);
2628 
2629 	if (system_supports_32bit_el0())
2630 		setup_elf_hwcaps(compat_elf_hwcaps);
2631 
2632 	if (system_uses_ttbr0_pan())
2633 		pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
2634 
2635 	sve_setup();
2636 	minsigstksz_setup();
2637 
2638 	/* Advertise that we have computed the system capabilities */
2639 	finalize_system_capabilities();
2640 
2641 	/*
2642 	 * Check for sane CTR_EL0.CWG value.
2643 	 */
2644 	cwg = cache_type_cwg();
2645 	if (!cwg)
2646 		pr_warn("No Cache Writeback Granule information, assuming %d\n",
2647 			ARCH_DMA_MINALIGN);
2648 }
2649 
2650 static bool __maybe_unused
2651 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
2652 {
2653 	return (__system_matches_cap(ARM64_HAS_PAN) && !__system_matches_cap(ARM64_HAS_UAO));
2654 }
2655 
2656 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
2657 {
2658 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
2659 }
2660 
2661 /*
2662  * We emulate only the following system register space.
2663  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
2664  * See Table C5-6 System instruction encodings for System register accesses,
2665  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
2666  */
2667 static inline bool __attribute_const__ is_emulated(u32 id)
2668 {
2669 	return (sys_reg_Op0(id) == 0x3 &&
2670 		sys_reg_CRn(id) == 0x0 &&
2671 		sys_reg_Op1(id) == 0x0 &&
2672 		(sys_reg_CRm(id) == 0 ||
2673 		 ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
2674 }
2675 
2676 /*
2677  * With CRm == 0, reg should be one of :
2678  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
2679  */
2680 static inline int emulate_id_reg(u32 id, u64 *valp)
2681 {
2682 	switch (id) {
2683 	case SYS_MIDR_EL1:
2684 		*valp = read_cpuid_id();
2685 		break;
2686 	case SYS_MPIDR_EL1:
2687 		*valp = SYS_MPIDR_SAFE_VAL;
2688 		break;
2689 	case SYS_REVIDR_EL1:
2690 		/* IMPLEMENTATION DEFINED values are emulated with 0 */
2691 		*valp = 0;
2692 		break;
2693 	default:
2694 		return -EINVAL;
2695 	}
2696 
2697 	return 0;
2698 }
2699 
2700 static int emulate_sys_reg(u32 id, u64 *valp)
2701 {
2702 	struct arm64_ftr_reg *regp;
2703 
2704 	if (!is_emulated(id))
2705 		return -EINVAL;
2706 
2707 	if (sys_reg_CRm(id) == 0)
2708 		return emulate_id_reg(id, valp);
2709 
2710 	regp = get_arm64_ftr_reg_nowarn(id);
2711 	if (regp)
2712 		*valp = arm64_ftr_reg_user_value(regp);
2713 	else
2714 		/*
2715 		 * The untracked registers are either IMPLEMENTATION DEFINED
2716 		 * (e.g, ID_AFR0_EL1) or reserved RAZ.
2717 		 */
2718 		*valp = 0;
2719 	return 0;
2720 }
2721 
2722 int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
2723 {
2724 	int rc;
2725 	u64 val;
2726 
2727 	rc = emulate_sys_reg(sys_reg, &val);
2728 	if (!rc) {
2729 		pt_regs_write_reg(regs, rt, val);
2730 		arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
2731 	}
2732 	return rc;
2733 }
2734 
2735 static int emulate_mrs(struct pt_regs *regs, u32 insn)
2736 {
2737 	u32 sys_reg, rt;
2738 
2739 	/*
2740 	 * sys_reg values are defined as used in mrs/msr instruction.
2741 	 * shift the imm value to get the encoding.
2742 	 */
2743 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
2744 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
2745 	return do_emulate_mrs(regs, sys_reg, rt);
2746 }
2747 
2748 static struct undef_hook mrs_hook = {
2749 	.instr_mask = 0xfff00000,
2750 	.instr_val  = 0xd5300000,
2751 	.pstate_mask = PSR_AA32_MODE_MASK,
2752 	.pstate_val = PSR_MODE_EL0t,
2753 	.fn = emulate_mrs,
2754 };
2755 
2756 static int __init enable_mrs_emulation(void)
2757 {
2758 	register_undef_hook(&mrs_hook);
2759 	return 0;
2760 }
2761 
2762 core_initcall(enable_mrs_emulation);
2763 
2764 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
2765 			  char *buf)
2766 {
2767 	if (__meltdown_safe)
2768 		return sprintf(buf, "Not affected\n");
2769 
2770 	if (arm64_kernel_unmapped_at_el0())
2771 		return sprintf(buf, "Mitigation: PTI\n");
2772 
2773 	return sprintf(buf, "Vulnerable\n");
2774 }
2775