xref: /openbmc/linux/arch/arm64/kernel/cpufeature.c (revision 9cfc5c90)
1 /*
2  * Contains CPU feature definitions
3  *
4  * Copyright (C) 2015 ARM Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #define pr_fmt(fmt) "CPU features: " fmt
20 
21 #include <linux/bsearch.h>
22 #include <linux/sort.h>
23 #include <linux/types.h>
24 #include <asm/cpu.h>
25 #include <asm/cpufeature.h>
26 #include <asm/cpu_ops.h>
27 #include <asm/processor.h>
28 #include <asm/sysreg.h>
29 
30 unsigned long elf_hwcap __read_mostly;
31 EXPORT_SYMBOL_GPL(elf_hwcap);
32 
33 #ifdef CONFIG_COMPAT
34 #define COMPAT_ELF_HWCAP_DEFAULT	\
35 				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
36 				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
37 				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
38 				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
39 				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
40 				 COMPAT_HWCAP_LPAE)
41 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
42 unsigned int compat_elf_hwcap2 __read_mostly;
43 #endif
44 
45 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
46 
47 #define ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
48 	{						\
49 		.strict = STRICT,			\
50 		.type = TYPE,				\
51 		.shift = SHIFT,				\
52 		.width = WIDTH,				\
53 		.safe_val = SAFE_VAL,			\
54 	}
55 
56 #define ARM64_FTR_END					\
57 	{						\
58 		.width = 0,				\
59 	}
60 
61 static struct arm64_ftr_bits ftr_id_aa64isar0[] = {
62 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
63 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
64 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),
65 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
66 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
67 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
68 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
69 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
70 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),	/* RAZ */
71 	ARM64_FTR_END,
72 };
73 
74 static struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
75 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
76 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),
77 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
78 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
79 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
80 	/* Linux doesn't care about the EL3 */
81 	ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64PFR0_EL3_SHIFT, 4, 0),
82 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL2_SHIFT, 4, 0),
83 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
84 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
85 	ARM64_FTR_END,
86 };
87 
88 static struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
89 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
90 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
91 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
92 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
93 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
94 	/* Linux shouldn't care about secure memory */
95 	ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
96 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
97 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
98 	/*
99 	 * Differing PARange is fine as long as all peripherals and memory are mapped
100 	 * within the minimum PARange of all CPUs
101 	 */
102 	ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
103 	ARM64_FTR_END,
104 };
105 
106 static struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
107 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
108 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
109 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
110 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
111 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
112 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
113 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
114 	ARM64_FTR_END,
115 };
116 
117 static struct arm64_ftr_bits ftr_ctr[] = {
118 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 31, 1, 1),	/* RAO */
119 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 3, 0),
120 	ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0),	/* CWG */
121 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),	/* ERG */
122 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1),	/* DminLine */
123 	/*
124 	 * Linux can handle differing I-cache policies. Userspace JITs will
125 	 * make use of *minLine
126 	 */
127 	ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, 0),	/* L1Ip */
128 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 10, 0),	/* RAZ */
129 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* IminLine */
130 	ARM64_FTR_END,
131 };
132 
133 static struct arm64_ftr_bits ftr_id_mmfr0[] = {
134 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),	/* InnerShr */
135 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),	/* FCSE */
136 	ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),	/* AuxReg */
137 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 4, 0),	/* TCM */
138 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),	/* ShareLvl */
139 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0),	/* OuterShr */
140 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),	/* PMSA */
141 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),	/* VMSA */
142 	ARM64_FTR_END,
143 };
144 
145 static struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
146 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
147 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
148 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
149 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
150 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
151 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
152 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
153 	ARM64_FTR_END,
154 };
155 
156 static struct arm64_ftr_bits ftr_mvfr2[] = {
157 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),	/* RAZ */
158 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),		/* FPMisc */
159 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),		/* SIMDMisc */
160 	ARM64_FTR_END,
161 };
162 
163 static struct arm64_ftr_bits ftr_dczid[] = {
164 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 5, 27, 0),	/* RAZ */
165 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 1, 1),		/* DZP */
166 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),	/* BS */
167 	ARM64_FTR_END,
168 };
169 
170 
171 static struct arm64_ftr_bits ftr_id_isar5[] = {
172 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
173 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 20, 4, 0),	/* RAZ */
174 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
175 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
176 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
177 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_AES_SHIFT, 4, 0),
178 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SEVL_SHIFT, 4, 0),
179 	ARM64_FTR_END,
180 };
181 
182 static struct arm64_ftr_bits ftr_id_mmfr4[] = {
183 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),	/* RAZ */
184 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),		/* ac2 */
185 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),		/* RAZ */
186 	ARM64_FTR_END,
187 };
188 
189 static struct arm64_ftr_bits ftr_id_pfr0[] = {
190 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 16, 0),	/* RAZ */
191 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),	/* State3 */
192 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0),		/* State2 */
193 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),		/* State1 */
194 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),		/* State0 */
195 	ARM64_FTR_END,
196 };
197 
198 /*
199  * Common ftr bits for a 32bit register with all hidden, strict
200  * attributes, with 4bit feature fields and a default safe value of
201  * 0. Covers the following 32bit registers:
202  * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
203  */
204 static struct arm64_ftr_bits ftr_generic_32bits[] = {
205 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
206 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
207 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
208 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
209 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
210 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
211 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
212 	ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
213 	ARM64_FTR_END,
214 };
215 
216 static struct arm64_ftr_bits ftr_generic[] = {
217 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
218 	ARM64_FTR_END,
219 };
220 
221 static struct arm64_ftr_bits ftr_generic32[] = {
222 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 32, 0),
223 	ARM64_FTR_END,
224 };
225 
226 static struct arm64_ftr_bits ftr_aa64raz[] = {
227 	ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
228 	ARM64_FTR_END,
229 };
230 
231 #define ARM64_FTR_REG(id, table)		\
232 	{					\
233 		.sys_id = id,			\
234 		.name = #id,			\
235 		.ftr_bits = &((table)[0]),	\
236 	}
237 
238 static struct arm64_ftr_reg arm64_ftr_regs[] = {
239 
240 	/* Op1 = 0, CRn = 0, CRm = 1 */
241 	ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
242 	ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
243 	ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_generic_32bits),
244 	ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
245 	ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
246 	ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
247 	ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
248 
249 	/* Op1 = 0, CRn = 0, CRm = 2 */
250 	ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
251 	ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
252 	ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
253 	ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
254 	ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
255 	ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
256 	ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
257 
258 	/* Op1 = 0, CRn = 0, CRm = 3 */
259 	ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
260 	ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
261 	ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
262 
263 	/* Op1 = 0, CRn = 0, CRm = 4 */
264 	ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
265 	ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_aa64raz),
266 
267 	/* Op1 = 0, CRn = 0, CRm = 5 */
268 	ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
269 	ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_generic),
270 
271 	/* Op1 = 0, CRn = 0, CRm = 6 */
272 	ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
273 	ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_aa64raz),
274 
275 	/* Op1 = 0, CRn = 0, CRm = 7 */
276 	ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
277 	ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
278 
279 	/* Op1 = 3, CRn = 0, CRm = 0 */
280 	ARM64_FTR_REG(SYS_CTR_EL0, ftr_ctr),
281 	ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
282 
283 	/* Op1 = 3, CRn = 14, CRm = 0 */
284 	ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_generic32),
285 };
286 
287 static int search_cmp_ftr_reg(const void *id, const void *regp)
288 {
289 	return (int)(unsigned long)id - (int)((const struct arm64_ftr_reg *)regp)->sys_id;
290 }
291 
292 /*
293  * get_arm64_ftr_reg - Lookup a feature register entry using its
294  * sys_reg() encoding. With the array arm64_ftr_regs sorted in the
295  * ascending order of sys_id , we use binary search to find a matching
296  * entry.
297  *
298  * returns - Upon success,  matching ftr_reg entry for id.
299  *         - NULL on failure. It is upto the caller to decide
300  *	     the impact of a failure.
301  */
302 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
303 {
304 	return bsearch((const void *)(unsigned long)sys_id,
305 			arm64_ftr_regs,
306 			ARRAY_SIZE(arm64_ftr_regs),
307 			sizeof(arm64_ftr_regs[0]),
308 			search_cmp_ftr_reg);
309 }
310 
311 static u64 arm64_ftr_set_value(struct arm64_ftr_bits *ftrp, s64 reg, s64 ftr_val)
312 {
313 	u64 mask = arm64_ftr_mask(ftrp);
314 
315 	reg &= ~mask;
316 	reg |= (ftr_val << ftrp->shift) & mask;
317 	return reg;
318 }
319 
320 static s64 arm64_ftr_safe_value(struct arm64_ftr_bits *ftrp, s64 new, s64 cur)
321 {
322 	s64 ret = 0;
323 
324 	switch (ftrp->type) {
325 	case FTR_EXACT:
326 		ret = ftrp->safe_val;
327 		break;
328 	case FTR_LOWER_SAFE:
329 		ret = new < cur ? new : cur;
330 		break;
331 	case FTR_HIGHER_SAFE:
332 		ret = new > cur ? new : cur;
333 		break;
334 	default:
335 		BUG();
336 	}
337 
338 	return ret;
339 }
340 
341 static int __init sort_cmp_ftr_regs(const void *a, const void *b)
342 {
343 	return ((const struct arm64_ftr_reg *)a)->sys_id -
344 		 ((const struct arm64_ftr_reg *)b)->sys_id;
345 }
346 
347 static void __init swap_ftr_regs(void *a, void *b, int size)
348 {
349 	struct arm64_ftr_reg tmp = *(struct arm64_ftr_reg *)a;
350 	*(struct arm64_ftr_reg *)a = *(struct arm64_ftr_reg *)b;
351 	*(struct arm64_ftr_reg *)b = tmp;
352 }
353 
354 static void __init sort_ftr_regs(void)
355 {
356 	/* Keep the array sorted so that we can do the binary search */
357 	sort(arm64_ftr_regs,
358 		ARRAY_SIZE(arm64_ftr_regs),
359 		sizeof(arm64_ftr_regs[0]),
360 		sort_cmp_ftr_regs,
361 		swap_ftr_regs);
362 }
363 
364 /*
365  * Initialise the CPU feature register from Boot CPU values.
366  * Also initiliases the strict_mask for the register.
367  */
368 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
369 {
370 	u64 val = 0;
371 	u64 strict_mask = ~0x0ULL;
372 	struct arm64_ftr_bits *ftrp;
373 	struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
374 
375 	BUG_ON(!reg);
376 
377 	for (ftrp  = reg->ftr_bits; ftrp->width; ftrp++) {
378 		s64 ftr_new = arm64_ftr_value(ftrp, new);
379 
380 		val = arm64_ftr_set_value(ftrp, val, ftr_new);
381 		if (!ftrp->strict)
382 			strict_mask &= ~arm64_ftr_mask(ftrp);
383 	}
384 	reg->sys_val = val;
385 	reg->strict_mask = strict_mask;
386 }
387 
388 void __init init_cpu_features(struct cpuinfo_arm64 *info)
389 {
390 	/* Before we start using the tables, make sure it is sorted */
391 	sort_ftr_regs();
392 
393 	init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
394 	init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
395 	init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
396 	init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
397 	init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
398 	init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
399 	init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
400 	init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
401 	init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
402 	init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
403 	init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
404 	init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
405 	init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
406 	init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
407 	init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
408 	init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
409 	init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
410 	init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
411 	init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
412 	init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
413 	init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
414 	init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
415 	init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
416 	init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
417 	init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
418 	init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
419 	init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
420 }
421 
422 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
423 {
424 	struct arm64_ftr_bits *ftrp;
425 
426 	for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
427 		s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
428 		s64 ftr_new = arm64_ftr_value(ftrp, new);
429 
430 		if (ftr_cur == ftr_new)
431 			continue;
432 		/* Find a safe value */
433 		ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
434 		reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
435 	}
436 
437 }
438 
439 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
440 {
441 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
442 
443 	BUG_ON(!regp);
444 	update_cpu_ftr_reg(regp, val);
445 	if ((boot & regp->strict_mask) == (val & regp->strict_mask))
446 		return 0;
447 	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
448 			regp->name, boot, cpu, val);
449 	return 1;
450 }
451 
452 /*
453  * Update system wide CPU feature registers with the values from a
454  * non-boot CPU. Also performs SANITY checks to make sure that there
455  * aren't any insane variations from that of the boot CPU.
456  */
457 void update_cpu_features(int cpu,
458 			 struct cpuinfo_arm64 *info,
459 			 struct cpuinfo_arm64 *boot)
460 {
461 	int taint = 0;
462 
463 	/*
464 	 * The kernel can handle differing I-cache policies, but otherwise
465 	 * caches should look identical. Userspace JITs will make use of
466 	 * *minLine.
467 	 */
468 	taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
469 				      info->reg_ctr, boot->reg_ctr);
470 
471 	/*
472 	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
473 	 * could result in too much or too little memory being zeroed if a
474 	 * process is preempted and migrated between CPUs.
475 	 */
476 	taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
477 				      info->reg_dczid, boot->reg_dczid);
478 
479 	/* If different, timekeeping will be broken (especially with KVM) */
480 	taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
481 				      info->reg_cntfrq, boot->reg_cntfrq);
482 
483 	/*
484 	 * The kernel uses self-hosted debug features and expects CPUs to
485 	 * support identical debug features. We presently need CTX_CMPs, WRPs,
486 	 * and BRPs to be identical.
487 	 * ID_AA64DFR1 is currently RES0.
488 	 */
489 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
490 				      info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
491 	taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
492 				      info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
493 	/*
494 	 * Even in big.LITTLE, processors should be identical instruction-set
495 	 * wise.
496 	 */
497 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
498 				      info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
499 	taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
500 				      info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
501 
502 	/*
503 	 * Differing PARange support is fine as long as all peripherals and
504 	 * memory are mapped within the minimum PARange of all CPUs.
505 	 * Linux should not care about secure memory.
506 	 */
507 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
508 				      info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
509 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
510 				      info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
511 
512 	/*
513 	 * EL3 is not our concern.
514 	 * ID_AA64PFR1 is currently RES0.
515 	 */
516 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
517 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
518 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
519 				      info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
520 
521 	/*
522 	 * If we have AArch32, we care about 32-bit features for compat. These
523 	 * registers should be RES0 otherwise.
524 	 */
525 	taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
526 					info->reg_id_dfr0, boot->reg_id_dfr0);
527 	taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
528 					info->reg_id_isar0, boot->reg_id_isar0);
529 	taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
530 					info->reg_id_isar1, boot->reg_id_isar1);
531 	taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
532 					info->reg_id_isar2, boot->reg_id_isar2);
533 	taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
534 					info->reg_id_isar3, boot->reg_id_isar3);
535 	taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
536 					info->reg_id_isar4, boot->reg_id_isar4);
537 	taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
538 					info->reg_id_isar5, boot->reg_id_isar5);
539 
540 	/*
541 	 * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
542 	 * ACTLR formats could differ across CPUs and therefore would have to
543 	 * be trapped for virtualization anyway.
544 	 */
545 	taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
546 					info->reg_id_mmfr0, boot->reg_id_mmfr0);
547 	taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
548 					info->reg_id_mmfr1, boot->reg_id_mmfr1);
549 	taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
550 					info->reg_id_mmfr2, boot->reg_id_mmfr2);
551 	taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
552 					info->reg_id_mmfr3, boot->reg_id_mmfr3);
553 	taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
554 					info->reg_id_pfr0, boot->reg_id_pfr0);
555 	taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
556 					info->reg_id_pfr1, boot->reg_id_pfr1);
557 	taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
558 					info->reg_mvfr0, boot->reg_mvfr0);
559 	taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
560 					info->reg_mvfr1, boot->reg_mvfr1);
561 	taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
562 					info->reg_mvfr2, boot->reg_mvfr2);
563 
564 	/*
565 	 * Mismatched CPU features are a recipe for disaster. Don't even
566 	 * pretend to support them.
567 	 */
568 	WARN_TAINT_ONCE(taint, TAINT_CPU_OUT_OF_SPEC,
569 			"Unsupported CPU feature variation.\n");
570 }
571 
572 u64 read_system_reg(u32 id)
573 {
574 	struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
575 
576 	/* We shouldn't get a request for an unsupported register */
577 	BUG_ON(!regp);
578 	return regp->sys_val;
579 }
580 
581 #include <linux/irqchip/arm-gic-v3.h>
582 
583 static bool
584 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
585 {
586 	int val = cpuid_feature_extract_field(reg, entry->field_pos);
587 
588 	return val >= entry->min_field_value;
589 }
590 
591 static bool
592 has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
593 {
594 	u64 val;
595 
596 	val = read_system_reg(entry->sys_reg);
597 	return feature_matches(val, entry);
598 }
599 
600 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
601 {
602 	bool has_sre;
603 
604 	if (!has_cpuid_feature(entry))
605 		return false;
606 
607 	has_sre = gic_enable_sre();
608 	if (!has_sre)
609 		pr_warn_once("%s present but disabled by higher exception level\n",
610 			     entry->desc);
611 
612 	return has_sre;
613 }
614 
615 static const struct arm64_cpu_capabilities arm64_features[] = {
616 	{
617 		.desc = "GIC system register CPU interface",
618 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
619 		.matches = has_useable_gicv3_cpuif,
620 		.sys_reg = SYS_ID_AA64PFR0_EL1,
621 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
622 		.min_field_value = 1,
623 	},
624 #ifdef CONFIG_ARM64_PAN
625 	{
626 		.desc = "Privileged Access Never",
627 		.capability = ARM64_HAS_PAN,
628 		.matches = has_cpuid_feature,
629 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
630 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
631 		.min_field_value = 1,
632 		.enable = cpu_enable_pan,
633 	},
634 #endif /* CONFIG_ARM64_PAN */
635 #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
636 	{
637 		.desc = "LSE atomic instructions",
638 		.capability = ARM64_HAS_LSE_ATOMICS,
639 		.matches = has_cpuid_feature,
640 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
641 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
642 		.min_field_value = 2,
643 	},
644 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
645 	{},
646 };
647 
648 #define HWCAP_CAP(reg, field, min_value, type, cap)		\
649 	{							\
650 		.desc = #cap,					\
651 		.matches = has_cpuid_feature,			\
652 		.sys_reg = reg,					\
653 		.field_pos = field,				\
654 		.min_field_value = min_value,			\
655 		.hwcap_type = type,				\
656 		.hwcap = cap,					\
657 	}
658 
659 static const struct arm64_cpu_capabilities arm64_hwcaps[] = {
660 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 2, CAP_HWCAP, HWCAP_PMULL),
661 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 1, CAP_HWCAP, HWCAP_AES),
662 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, 1, CAP_HWCAP, HWCAP_SHA1),
663 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, 1, CAP_HWCAP, HWCAP_SHA2),
664 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, 1, CAP_HWCAP, HWCAP_CRC32),
665 	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, 2, CAP_HWCAP, HWCAP_ATOMICS),
666 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, 0, CAP_HWCAP, HWCAP_FP),
667 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, 0, CAP_HWCAP, HWCAP_ASIMD),
668 #ifdef CONFIG_COMPAT
669 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
670 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
671 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
672 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
673 	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
674 #endif
675 	{},
676 };
677 
678 static void cap_set_hwcap(const struct arm64_cpu_capabilities *cap)
679 {
680 	switch (cap->hwcap_type) {
681 	case CAP_HWCAP:
682 		elf_hwcap |= cap->hwcap;
683 		break;
684 #ifdef CONFIG_COMPAT
685 	case CAP_COMPAT_HWCAP:
686 		compat_elf_hwcap |= (u32)cap->hwcap;
687 		break;
688 	case CAP_COMPAT_HWCAP2:
689 		compat_elf_hwcap2 |= (u32)cap->hwcap;
690 		break;
691 #endif
692 	default:
693 		WARN_ON(1);
694 		break;
695 	}
696 }
697 
698 /* Check if we have a particular HWCAP enabled */
699 static bool __maybe_unused cpus_have_hwcap(const struct arm64_cpu_capabilities *cap)
700 {
701 	bool rc;
702 
703 	switch (cap->hwcap_type) {
704 	case CAP_HWCAP:
705 		rc = (elf_hwcap & cap->hwcap) != 0;
706 		break;
707 #ifdef CONFIG_COMPAT
708 	case CAP_COMPAT_HWCAP:
709 		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
710 		break;
711 	case CAP_COMPAT_HWCAP2:
712 		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
713 		break;
714 #endif
715 	default:
716 		WARN_ON(1);
717 		rc = false;
718 	}
719 
720 	return rc;
721 }
722 
723 static void setup_cpu_hwcaps(void)
724 {
725 	int i;
726 	const struct arm64_cpu_capabilities *hwcaps = arm64_hwcaps;
727 
728 	for (i = 0; hwcaps[i].desc; i++)
729 		if (hwcaps[i].matches(&hwcaps[i]))
730 			cap_set_hwcap(&hwcaps[i]);
731 }
732 
733 void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
734 			    const char *info)
735 {
736 	int i;
737 
738 	for (i = 0; caps[i].desc; i++) {
739 		if (!caps[i].matches(&caps[i]))
740 			continue;
741 
742 		if (!cpus_have_cap(caps[i].capability))
743 			pr_info("%s %s\n", info, caps[i].desc);
744 		cpus_set_cap(caps[i].capability);
745 	}
746 }
747 
748 /*
749  * Run through the enabled capabilities and enable() it on all active
750  * CPUs
751  */
752 static void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
753 {
754 	int i;
755 
756 	for (i = 0; caps[i].desc; i++)
757 		if (caps[i].enable && cpus_have_cap(caps[i].capability))
758 			on_each_cpu(caps[i].enable, NULL, true);
759 }
760 
761 #ifdef CONFIG_HOTPLUG_CPU
762 
763 /*
764  * Flag to indicate if we have computed the system wide
765  * capabilities based on the boot time active CPUs. This
766  * will be used to determine if a new booting CPU should
767  * go through the verification process to make sure that it
768  * supports the system capabilities, without using a hotplug
769  * notifier.
770  */
771 static bool sys_caps_initialised;
772 
773 static inline void set_sys_caps_initialised(void)
774 {
775 	sys_caps_initialised = true;
776 }
777 
778 /*
779  * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
780  */
781 static u64 __raw_read_system_reg(u32 sys_id)
782 {
783 	switch (sys_id) {
784 	case SYS_ID_PFR0_EL1:		return (u64)read_cpuid(ID_PFR0_EL1);
785 	case SYS_ID_PFR1_EL1:		return (u64)read_cpuid(ID_PFR1_EL1);
786 	case SYS_ID_DFR0_EL1:		return (u64)read_cpuid(ID_DFR0_EL1);
787 	case SYS_ID_MMFR0_EL1:		return (u64)read_cpuid(ID_MMFR0_EL1);
788 	case SYS_ID_MMFR1_EL1:		return (u64)read_cpuid(ID_MMFR1_EL1);
789 	case SYS_ID_MMFR2_EL1:		return (u64)read_cpuid(ID_MMFR2_EL1);
790 	case SYS_ID_MMFR3_EL1:		return (u64)read_cpuid(ID_MMFR3_EL1);
791 	case SYS_ID_ISAR0_EL1:		return (u64)read_cpuid(ID_ISAR0_EL1);
792 	case SYS_ID_ISAR1_EL1:		return (u64)read_cpuid(ID_ISAR1_EL1);
793 	case SYS_ID_ISAR2_EL1:		return (u64)read_cpuid(ID_ISAR2_EL1);
794 	case SYS_ID_ISAR3_EL1:		return (u64)read_cpuid(ID_ISAR3_EL1);
795 	case SYS_ID_ISAR4_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
796 	case SYS_ID_ISAR5_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
797 	case SYS_MVFR0_EL1:		return (u64)read_cpuid(MVFR0_EL1);
798 	case SYS_MVFR1_EL1:		return (u64)read_cpuid(MVFR1_EL1);
799 	case SYS_MVFR2_EL1:		return (u64)read_cpuid(MVFR2_EL1);
800 
801 	case SYS_ID_AA64PFR0_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
802 	case SYS_ID_AA64PFR1_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
803 	case SYS_ID_AA64DFR0_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
804 	case SYS_ID_AA64DFR1_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
805 	case SYS_ID_AA64MMFR0_EL1:	return (u64)read_cpuid(ID_AA64MMFR0_EL1);
806 	case SYS_ID_AA64MMFR1_EL1:	return (u64)read_cpuid(ID_AA64MMFR1_EL1);
807 	case SYS_ID_AA64ISAR0_EL1:	return (u64)read_cpuid(ID_AA64ISAR0_EL1);
808 	case SYS_ID_AA64ISAR1_EL1:	return (u64)read_cpuid(ID_AA64ISAR1_EL1);
809 
810 	case SYS_CNTFRQ_EL0:		return (u64)read_cpuid(CNTFRQ_EL0);
811 	case SYS_CTR_EL0:		return (u64)read_cpuid(CTR_EL0);
812 	case SYS_DCZID_EL0:		return (u64)read_cpuid(DCZID_EL0);
813 	default:
814 		BUG();
815 		return 0;
816 	}
817 }
818 
819 /*
820  * Park the CPU which doesn't have the capability as advertised
821  * by the system.
822  */
823 static void fail_incapable_cpu(char *cap_type,
824 				 const struct arm64_cpu_capabilities *cap)
825 {
826 	int cpu = smp_processor_id();
827 
828 	pr_crit("CPU%d: missing %s : %s\n", cpu, cap_type, cap->desc);
829 	/* Mark this CPU absent */
830 	set_cpu_present(cpu, 0);
831 
832 	/* Check if we can park ourselves */
833 	if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die)
834 		cpu_ops[cpu]->cpu_die(cpu);
835 	asm(
836 	"1:	wfe\n"
837 	"	wfi\n"
838 	"	b	1b");
839 }
840 
841 /*
842  * Run through the enabled system capabilities and enable() it on this CPU.
843  * The capabilities were decided based on the available CPUs at the boot time.
844  * Any new CPU should match the system wide status of the capability. If the
845  * new CPU doesn't have a capability which the system now has enabled, we
846  * cannot do anything to fix it up and could cause unexpected failures. So
847  * we park the CPU.
848  */
849 void verify_local_cpu_capabilities(void)
850 {
851 	int i;
852 	const struct arm64_cpu_capabilities *caps;
853 
854 	/*
855 	 * If we haven't computed the system capabilities, there is nothing
856 	 * to verify.
857 	 */
858 	if (!sys_caps_initialised)
859 		return;
860 
861 	caps = arm64_features;
862 	for (i = 0; caps[i].desc; i++) {
863 		if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg)
864 			continue;
865 		/*
866 		 * If the new CPU misses an advertised feature, we cannot proceed
867 		 * further, park the cpu.
868 		 */
869 		if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
870 			fail_incapable_cpu("arm64_features", &caps[i]);
871 		if (caps[i].enable)
872 			caps[i].enable(NULL);
873 	}
874 
875 	for (i = 0, caps = arm64_hwcaps; caps[i].desc; i++) {
876 		if (!cpus_have_hwcap(&caps[i]))
877 			continue;
878 		if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
879 			fail_incapable_cpu("arm64_hwcaps", &caps[i]);
880 	}
881 }
882 
883 #else	/* !CONFIG_HOTPLUG_CPU */
884 
885 static inline void set_sys_caps_initialised(void)
886 {
887 }
888 
889 #endif	/* CONFIG_HOTPLUG_CPU */
890 
891 static void setup_feature_capabilities(void)
892 {
893 	update_cpu_capabilities(arm64_features, "detected feature:");
894 	enable_cpu_capabilities(arm64_features);
895 }
896 
897 void __init setup_cpu_features(void)
898 {
899 	u32 cwg;
900 	int cls;
901 
902 	/* Set the CPU feature capabilies */
903 	setup_feature_capabilities();
904 	setup_cpu_hwcaps();
905 
906 	/* Advertise that we have computed the system capabilities */
907 	set_sys_caps_initialised();
908 
909 	/*
910 	 * Check for sane CTR_EL0.CWG value.
911 	 */
912 	cwg = cache_type_cwg();
913 	cls = cache_line_size();
914 	if (!cwg)
915 		pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
916 			cls);
917 	if (L1_CACHE_BYTES < cls)
918 		pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
919 			L1_CACHE_BYTES, cls);
920 }
921