1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2017, Nicholas Piggin, IBM Corporation
4  */
5 
6 #define pr_fmt(fmt) "dt-cpu-ftrs: " fmt
7 
8 #include <linux/export.h>
9 #include <linux/init.h>
10 #include <linux/jump_label.h>
11 #include <linux/libfdt.h>
12 #include <linux/memblock.h>
13 #include <linux/of_fdt.h>
14 #include <linux/printk.h>
15 #include <linux/sched.h>
16 #include <linux/string.h>
17 #include <linux/threads.h>
18 
19 #include <asm/cputable.h>
20 #include <asm/dt_cpu_ftrs.h>
21 #include <asm/mce.h>
22 #include <asm/mmu.h>
23 #include <asm/setup.h>
24 
25 
26 /* Device-tree visible constants follow */
27 #define ISA_V3_0B       3000
28 #define ISA_V3_1        3100
29 
30 #define USABLE_PR               (1U << 0)
31 #define USABLE_OS               (1U << 1)
32 #define USABLE_HV               (1U << 2)
33 
34 #define HV_SUPPORT_HFSCR        (1U << 0)
35 #define OS_SUPPORT_FSCR         (1U << 0)
36 
37 /* For parsing, we define all bits set as "NONE" case */
38 #define HV_SUPPORT_NONE		0xffffffffU
39 #define OS_SUPPORT_NONE		0xffffffffU
40 
41 struct dt_cpu_feature {
42 	const char *name;
43 	uint32_t isa;
44 	uint32_t usable_privilege;
45 	uint32_t hv_support;
46 	uint32_t os_support;
47 	uint32_t hfscr_bit_nr;
48 	uint32_t fscr_bit_nr;
49 	uint32_t hwcap_bit_nr;
50 	/* fdt parsing */
51 	unsigned long node;
52 	int enabled;
53 	int disabled;
54 };
55 
56 #define MMU_FTRS_HASH_BASE (MMU_FTRS_POWER8)
57 
58 #define COMMON_USER_BASE	(PPC_FEATURE_32 | PPC_FEATURE_64 | \
59 				 PPC_FEATURE_ARCH_2_06 |\
60 				 PPC_FEATURE_ICACHE_SNOOP)
61 #define COMMON_USER2_BASE	(PPC_FEATURE2_ARCH_2_07 | \
62 				 PPC_FEATURE2_ISEL)
63 /*
64  * Set up the base CPU
65  */
66 
67 static int hv_mode;
68 
69 static struct {
70 	u64	lpcr;
71 	u64	hfscr;
72 	u64	fscr;
73 	u64	pcr;
74 } system_registers;
75 
76 static void (*init_pmu_registers)(void);
77 
78 static void __restore_cpu_cpufeatures(void)
79 {
80 	mtspr(SPRN_LPCR, system_registers.lpcr);
81 	if (hv_mode) {
82 		mtspr(SPRN_LPID, 0);
83 		mtspr(SPRN_AMOR, ~0);
84 		mtspr(SPRN_HFSCR, system_registers.hfscr);
85 		mtspr(SPRN_PCR, system_registers.pcr);
86 	}
87 	mtspr(SPRN_FSCR, system_registers.fscr);
88 
89 	if (init_pmu_registers)
90 		init_pmu_registers();
91 }
92 
93 static char dt_cpu_name[64];
94 
95 static struct cpu_spec __initdata base_cpu_spec = {
96 	.cpu_name		= NULL,
97 	.cpu_features		= CPU_FTRS_DT_CPU_BASE,
98 	.cpu_user_features	= COMMON_USER_BASE,
99 	.cpu_user_features2	= COMMON_USER2_BASE,
100 	.mmu_features		= 0,
101 	.icache_bsize		= 32, /* minimum block size, fixed by */
102 	.dcache_bsize		= 32, /* cache info init.             */
103 	.num_pmcs		= 0,
104 	.pmc_type		= PPC_PMC_DEFAULT,
105 	.cpu_setup		= NULL,
106 	.cpu_restore		= __restore_cpu_cpufeatures,
107 	.machine_check_early	= NULL,
108 	.platform		= NULL,
109 };
110 
111 static void __init cpufeatures_setup_cpu(void)
112 {
113 	set_cur_cpu_spec(&base_cpu_spec);
114 
115 	cur_cpu_spec->pvr_mask = -1;
116 	cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
117 
118 	/* Initialize the base environment -- clear FSCR/HFSCR.  */
119 	hv_mode = !!(mfmsr() & MSR_HV);
120 	if (hv_mode) {
121 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
122 		mtspr(SPRN_HFSCR, 0);
123 	}
124 	mtspr(SPRN_FSCR, 0);
125 	mtspr(SPRN_PCR, PCR_MASK);
126 
127 	/*
128 	 * LPCR does not get cleared, to match behaviour with secondaries
129 	 * in __restore_cpu_cpufeatures. Once the idle code is fixed, this
130 	 * could clear LPCR too.
131 	 */
132 }
133 
134 static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
135 {
136 	if (f->hv_support == HV_SUPPORT_NONE) {
137 	} else if (f->hv_support & HV_SUPPORT_HFSCR) {
138 		u64 hfscr = mfspr(SPRN_HFSCR);
139 		hfscr |= 1UL << f->hfscr_bit_nr;
140 		mtspr(SPRN_HFSCR, hfscr);
141 	} else {
142 		/* Does not have a known recipe */
143 		return 0;
144 	}
145 
146 	if (f->os_support == OS_SUPPORT_NONE) {
147 	} else if (f->os_support & OS_SUPPORT_FSCR) {
148 		u64 fscr = mfspr(SPRN_FSCR);
149 		fscr |= 1UL << f->fscr_bit_nr;
150 		mtspr(SPRN_FSCR, fscr);
151 	} else {
152 		/* Does not have a known recipe */
153 		return 0;
154 	}
155 
156 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
157 		uint32_t word = f->hwcap_bit_nr / 32;
158 		uint32_t bit = f->hwcap_bit_nr % 32;
159 
160 		if (word == 0)
161 			cur_cpu_spec->cpu_user_features |= 1U << bit;
162 		else if (word == 1)
163 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
164 		else
165 			pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
166 	}
167 
168 	return 1;
169 }
170 
171 static int __init feat_enable(struct dt_cpu_feature *f)
172 {
173 	if (f->hv_support != HV_SUPPORT_NONE) {
174 		if (f->hfscr_bit_nr != -1) {
175 			u64 hfscr = mfspr(SPRN_HFSCR);
176 			hfscr |= 1UL << f->hfscr_bit_nr;
177 			mtspr(SPRN_HFSCR, hfscr);
178 		}
179 	}
180 
181 	if (f->os_support != OS_SUPPORT_NONE) {
182 		if (f->fscr_bit_nr != -1) {
183 			u64 fscr = mfspr(SPRN_FSCR);
184 			fscr |= 1UL << f->fscr_bit_nr;
185 			mtspr(SPRN_FSCR, fscr);
186 		}
187 	}
188 
189 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
190 		uint32_t word = f->hwcap_bit_nr / 32;
191 		uint32_t bit = f->hwcap_bit_nr % 32;
192 
193 		if (word == 0)
194 			cur_cpu_spec->cpu_user_features |= 1U << bit;
195 		else if (word == 1)
196 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
197 		else
198 			pr_err("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
199 	}
200 
201 	return 1;
202 }
203 
204 static int __init feat_disable(struct dt_cpu_feature *f)
205 {
206 	return 0;
207 }
208 
209 static int __init feat_enable_hv(struct dt_cpu_feature *f)
210 {
211 	u64 lpcr;
212 
213 	if (!hv_mode) {
214 		pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
215 		return 0;
216 	}
217 
218 	mtspr(SPRN_LPID, 0);
219 	mtspr(SPRN_AMOR, ~0);
220 
221 	lpcr = mfspr(SPRN_LPCR);
222 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
223 	mtspr(SPRN_LPCR, lpcr);
224 
225 	cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
226 
227 	return 1;
228 }
229 
230 static int __init feat_enable_le(struct dt_cpu_feature *f)
231 {
232 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
233 	return 1;
234 }
235 
236 static int __init feat_enable_smt(struct dt_cpu_feature *f)
237 {
238 	cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
239 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
240 	return 1;
241 }
242 
243 static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
244 {
245 	u64 lpcr;
246 
247 	/* Set PECE wakeup modes for ISA 207 */
248 	lpcr = mfspr(SPRN_LPCR);
249 	lpcr |=  LPCR_PECE0;
250 	lpcr |=  LPCR_PECE1;
251 	lpcr |=  LPCR_PECE2;
252 	mtspr(SPRN_LPCR, lpcr);
253 
254 	return 1;
255 }
256 
257 static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
258 {
259 	u64 lpcr;
260 
261 	/* Set PECE wakeup modes for ISAv3.0B */
262 	lpcr = mfspr(SPRN_LPCR);
263 	lpcr |=  LPCR_PECE0;
264 	lpcr |=  LPCR_PECE1;
265 	lpcr |=  LPCR_PECE2;
266 	mtspr(SPRN_LPCR, lpcr);
267 
268 	return 1;
269 }
270 
271 static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
272 {
273 	u64 lpcr;
274 
275 	if (!IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
276 		return 0;
277 
278 	lpcr = mfspr(SPRN_LPCR);
279 	lpcr &= ~LPCR_ISL;
280 
281 	/* VRMASD */
282 	lpcr |= LPCR_VPM0;
283 	lpcr &= ~LPCR_VPM1;
284 	lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
285 	mtspr(SPRN_LPCR, lpcr);
286 
287 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
288 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
289 
290 	return 1;
291 }
292 
293 static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
294 {
295 	u64 lpcr;
296 
297 	if (!IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
298 		return 0;
299 
300 	lpcr = mfspr(SPRN_LPCR);
301 	lpcr &= ~(LPCR_ISL | LPCR_UPRT | LPCR_HR);
302 	mtspr(SPRN_LPCR, lpcr);
303 
304 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
305 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
306 
307 	return 1;
308 }
309 
310 
311 static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
312 {
313 	if (!IS_ENABLED(CONFIG_PPC_RADIX_MMU))
314 		return 0;
315 
316 	cur_cpu_spec->mmu_features |= MMU_FTR_KERNEL_RO;
317 	cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
318 	cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
319 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
320 
321 	return 1;
322 }
323 
324 static int __init feat_enable_dscr(struct dt_cpu_feature *f)
325 {
326 	u64 lpcr;
327 
328 	/*
329 	 * Linux relies on FSCR[DSCR] being clear, so that we can take the
330 	 * facility unavailable interrupt and track the task's usage of DSCR.
331 	 * See facility_unavailable_exception().
332 	 * Clear the bit here so that feat_enable() doesn't set it.
333 	 */
334 	f->fscr_bit_nr = -1;
335 
336 	feat_enable(f);
337 
338 	lpcr = mfspr(SPRN_LPCR);
339 	lpcr &= ~LPCR_DPFD;
340 	lpcr |=  (4UL << LPCR_DPFD_SH);
341 	mtspr(SPRN_LPCR, lpcr);
342 
343 	return 1;
344 }
345 
346 static void __init hfscr_pmu_enable(void)
347 {
348 	u64 hfscr = mfspr(SPRN_HFSCR);
349 	hfscr |= PPC_BIT(60);
350 	mtspr(SPRN_HFSCR, hfscr);
351 }
352 
353 static void init_pmu_power8(void)
354 {
355 	if (hv_mode) {
356 		mtspr(SPRN_MMCRC, 0);
357 		mtspr(SPRN_MMCRH, 0);
358 	}
359 
360 	mtspr(SPRN_MMCRA, 0);
361 	mtspr(SPRN_MMCR0, MMCR0_FC);
362 	mtspr(SPRN_MMCR1, 0);
363 	mtspr(SPRN_MMCR2, 0);
364 	mtspr(SPRN_MMCRS, 0);
365 }
366 
367 static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
368 {
369 	cur_cpu_spec->platform = "power8";
370 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
371 
372 	return 1;
373 }
374 
375 static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
376 {
377 	hfscr_pmu_enable();
378 
379 	init_pmu_power8();
380 	init_pmu_registers = init_pmu_power8;
381 
382 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
383 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
384 	if (pvr_version_is(PVR_POWER8E))
385 		cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
386 
387 	cur_cpu_spec->num_pmcs		= 6;
388 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
389 
390 	return 1;
391 }
392 
393 static void init_pmu_power9(void)
394 {
395 	if (hv_mode)
396 		mtspr(SPRN_MMCRC, 0);
397 
398 	mtspr(SPRN_MMCRA, 0);
399 	mtspr(SPRN_MMCR0, MMCR0_FC);
400 	mtspr(SPRN_MMCR1, 0);
401 	mtspr(SPRN_MMCR2, 0);
402 }
403 
404 static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
405 {
406 	cur_cpu_spec->platform = "power9";
407 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
408 
409 	return 1;
410 }
411 
412 static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
413 {
414 	hfscr_pmu_enable();
415 
416 	init_pmu_power9();
417 	init_pmu_registers = init_pmu_power9;
418 
419 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
420 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
421 
422 	cur_cpu_spec->num_pmcs		= 6;
423 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
424 
425 	return 1;
426 }
427 
428 static void init_pmu_power10(void)
429 {
430 	init_pmu_power9();
431 
432 	mtspr(SPRN_MMCR3, 0);
433 	mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);
434 	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);
435 }
436 
437 static int __init feat_enable_pmu_power10(struct dt_cpu_feature *f)
438 {
439 	hfscr_pmu_enable();
440 
441 	init_pmu_power10();
442 	init_pmu_registers = init_pmu_power10;
443 
444 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
445 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
446 
447 	cur_cpu_spec->num_pmcs          = 6;
448 	cur_cpu_spec->pmc_type          = PPC_PMC_IBM;
449 
450 	return 1;
451 }
452 
453 static int __init feat_enable_mce_power10(struct dt_cpu_feature *f)
454 {
455 	cur_cpu_spec->platform = "power10";
456 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p10;
457 
458 	return 1;
459 }
460 
461 static int __init feat_enable_tm(struct dt_cpu_feature *f)
462 {
463 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
464 	feat_enable(f);
465 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
466 	return 1;
467 #endif
468 	return 0;
469 }
470 
471 static int __init feat_enable_fp(struct dt_cpu_feature *f)
472 {
473 	feat_enable(f);
474 	cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
475 
476 	return 1;
477 }
478 
479 static int __init feat_enable_vector(struct dt_cpu_feature *f)
480 {
481 #ifdef CONFIG_ALTIVEC
482 	feat_enable(f);
483 	cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
484 	cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
485 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
486 
487 	return 1;
488 #endif
489 	return 0;
490 }
491 
492 static int __init feat_enable_vsx(struct dt_cpu_feature *f)
493 {
494 #ifdef CONFIG_VSX
495 	feat_enable(f);
496 	cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
497 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
498 
499 	return 1;
500 #endif
501 	return 0;
502 }
503 
504 static int __init feat_enable_purr(struct dt_cpu_feature *f)
505 {
506 	cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
507 
508 	return 1;
509 }
510 
511 static int __init feat_enable_ebb(struct dt_cpu_feature *f)
512 {
513 	/*
514 	 * PPC_FEATURE2_EBB is enabled in PMU init code because it has
515 	 * historically been related to the PMU facility. This may have
516 	 * to be decoupled if EBB becomes more generic. For now, follow
517 	 * existing convention.
518 	 */
519 	f->hwcap_bit_nr = -1;
520 	feat_enable(f);
521 
522 	return 1;
523 }
524 
525 static int __init feat_enable_dbell(struct dt_cpu_feature *f)
526 {
527 	u64 lpcr;
528 
529 	/* P9 has an HFSCR for privileged state */
530 	feat_enable(f);
531 
532 	cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
533 
534 	lpcr = mfspr(SPRN_LPCR);
535 	lpcr |=  LPCR_PECEDH; /* hyp doorbell wakeup */
536 	mtspr(SPRN_LPCR, lpcr);
537 
538 	return 1;
539 }
540 
541 static int __init feat_enable_hvi(struct dt_cpu_feature *f)
542 {
543 	u64 lpcr;
544 
545 	/*
546 	 * POWER9 XIVE interrupts including in OPAL XICS compatibility
547 	 * are always delivered as hypervisor virtualization interrupts (HVI)
548 	 * rather than EE.
549 	 *
550 	 * However LPES0 is not set here, in the chance that an EE does get
551 	 * delivered to the host somehow, the EE handler would not expect it
552 	 * to be delivered in LPES0 mode (e.g., using SRR[01]). This could
553 	 * happen if there is a bug in interrupt controller code, or IC is
554 	 * misconfigured in systemsim.
555 	 */
556 
557 	lpcr = mfspr(SPRN_LPCR);
558 	lpcr |= LPCR_HVICE;	/* enable hvi interrupts */
559 	lpcr |= LPCR_HEIC;	/* disable ee interrupts when MSR_HV */
560 	lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
561 	mtspr(SPRN_LPCR, lpcr);
562 
563 	return 1;
564 }
565 
566 static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
567 {
568 	cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
569 
570 	return 1;
571 }
572 
573 static int __init feat_enable_mma(struct dt_cpu_feature *f)
574 {
575 	u64 pcr;
576 
577 	feat_enable(f);
578 	pcr = mfspr(SPRN_PCR);
579 	pcr &= ~PCR_MMA_DIS;
580 	mtspr(SPRN_PCR, pcr);
581 
582 	return 1;
583 }
584 
585 struct dt_cpu_feature_match {
586 	const char *name;
587 	int (*enable)(struct dt_cpu_feature *f);
588 	u64 cpu_ftr_bit_mask;
589 };
590 
591 static struct dt_cpu_feature_match __initdata
592 		dt_cpu_feature_match_table[] = {
593 	{"hypervisor", feat_enable_hv, 0},
594 	{"big-endian", feat_enable, 0},
595 	{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
596 	{"smt", feat_enable_smt, 0},
597 	{"interrupt-facilities", feat_enable, 0},
598 	{"system-call-vectored", feat_enable, 0},
599 	{"timer-facilities", feat_enable, 0},
600 	{"timer-facilities-v3", feat_enable, 0},
601 	{"debug-facilities", feat_enable, 0},
602 	{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
603 	{"branch-tracing", feat_enable, 0},
604 	{"floating-point", feat_enable_fp, 0},
605 	{"vector", feat_enable_vector, 0},
606 	{"vector-scalar", feat_enable_vsx, 0},
607 	{"vector-scalar-v3", feat_enable, 0},
608 	{"decimal-floating-point", feat_enable, 0},
609 	{"decimal-integer", feat_enable, 0},
610 	{"quadword-load-store", feat_enable, 0},
611 	{"vector-crypto", feat_enable, 0},
612 	{"mmu-hash", feat_enable_mmu_hash, 0},
613 	{"mmu-radix", feat_enable_mmu_radix, 0},
614 	{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
615 	{"virtual-page-class-key-protection", feat_enable, 0},
616 	{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
617 	{"transactional-memory-v3", feat_enable_tm, 0},
618 	{"tm-suspend-hypervisor-assist", feat_enable, CPU_FTR_P9_TM_HV_ASSIST},
619 	{"tm-suspend-xer-so-bug", feat_enable, CPU_FTR_P9_TM_XER_SO_BUG},
620 	{"idle-nap", feat_enable_idle_nap, 0},
621 	/* alignment-interrupt-dsisr ignored */
622 	{"idle-stop", feat_enable_idle_stop, 0},
623 	{"machine-check-power8", feat_enable_mce_power8, 0},
624 	{"performance-monitor-power8", feat_enable_pmu_power8, 0},
625 	{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
626 	{"event-based-branch", feat_enable_ebb, 0},
627 	{"target-address-register", feat_enable, 0},
628 	{"branch-history-rolling-buffer", feat_enable, 0},
629 	{"control-register", feat_enable, CPU_FTR_CTRL},
630 	{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
631 	{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
632 	{"processor-utilization-of-resources-register", feat_enable_purr, 0},
633 	{"no-execute", feat_enable, 0},
634 	{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
635 	{"cache-inhibited-large-page", feat_enable_large_ci, 0},
636 	{"coprocessor-icswx", feat_enable, 0},
637 	{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
638 	{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
639 	{"wait", feat_enable, 0},
640 	{"atomic-memory-operations", feat_enable, 0},
641 	{"branch-v3", feat_enable, 0},
642 	{"copy-paste", feat_enable, 0},
643 	{"decimal-floating-point-v3", feat_enable, 0},
644 	{"decimal-integer-v3", feat_enable, 0},
645 	{"fixed-point-v3", feat_enable, 0},
646 	{"floating-point-v3", feat_enable, 0},
647 	{"group-start-register", feat_enable, 0},
648 	{"pc-relative-addressing", feat_enable, 0},
649 	{"machine-check-power9", feat_enable_mce_power9, 0},
650 	{"machine-check-power10", feat_enable_mce_power10, 0},
651 	{"performance-monitor-power9", feat_enable_pmu_power9, 0},
652 	{"performance-monitor-power10", feat_enable_pmu_power10, 0},
653 	{"event-based-branch-v3", feat_enable, 0},
654 	{"random-number-generator", feat_enable, 0},
655 	{"system-call-vectored", feat_disable, 0},
656 	{"trace-interrupt-v3", feat_enable, 0},
657 	{"vector-v3", feat_enable, 0},
658 	{"vector-binary128", feat_enable, 0},
659 	{"vector-binary16", feat_enable, 0},
660 	{"wait-v3", feat_enable, 0},
661 	{"prefix-instructions", feat_enable, 0},
662 	{"matrix-multiply-assist", feat_enable_mma, 0},
663 	{"debug-facilities-v31", feat_enable, CPU_FTR_DAWR1},
664 };
665 
666 static bool __initdata using_dt_cpu_ftrs;
667 static bool __initdata enable_unknown = true;
668 
669 static int __init dt_cpu_ftrs_parse(char *str)
670 {
671 	if (!str)
672 		return 0;
673 
674 	if (!strcmp(str, "off"))
675 		using_dt_cpu_ftrs = false;
676 	else if (!strcmp(str, "known"))
677 		enable_unknown = false;
678 	else
679 		return 1;
680 
681 	return 0;
682 }
683 early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
684 
685 static void __init cpufeatures_setup_start(u32 isa)
686 {
687 	pr_info("setup for ISA %d\n", isa);
688 
689 	if (isa >= ISA_V3_0B) {
690 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
691 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
692 	}
693 
694 	if (isa >= ISA_V3_1) {
695 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_31;
696 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_1;
697 	}
698 }
699 
700 static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
701 {
702 	const struct dt_cpu_feature_match *m;
703 	bool known = false;
704 	int i;
705 
706 	for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
707 		m = &dt_cpu_feature_match_table[i];
708 		if (!strcmp(f->name, m->name)) {
709 			known = true;
710 			if (m->enable(f)) {
711 				cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
712 				break;
713 			}
714 
715 			pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
716 				f->name);
717 			return false;
718 		}
719 	}
720 
721 	if (!known && (!enable_unknown || !feat_try_enable_unknown(f))) {
722 		pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
723 			f->name);
724 		return false;
725 	}
726 
727 	if (known)
728 		pr_debug("enabling: %s\n", f->name);
729 	else
730 		pr_debug("enabling: %s (unknown)\n", f->name);
731 
732 	return true;
733 }
734 
735 /*
736  * Handle POWER9 broadcast tlbie invalidation issue using
737  * cpu feature flag.
738  */
739 static __init void update_tlbie_feature_flag(unsigned long pvr)
740 {
741 	if (PVR_VER(pvr) == PVR_POWER9) {
742 		/*
743 		 * Set the tlbie feature flag for anything below
744 		 * Nimbus DD 2.3 and Cumulus DD 1.3
745 		 */
746 		if ((pvr & 0xe000) == 0) {
747 			/* Nimbus */
748 			if ((pvr & 0xfff) < 0x203)
749 				cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
750 		} else if ((pvr & 0xc000) == 0) {
751 			/* Cumulus */
752 			if ((pvr & 0xfff) < 0x103)
753 				cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
754 		} else {
755 			WARN_ONCE(1, "Unknown PVR");
756 			cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
757 		}
758 
759 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_ERAT_BUG;
760 	}
761 }
762 
763 static __init void cpufeatures_cpu_quirks(void)
764 {
765 	unsigned long version = mfspr(SPRN_PVR);
766 
767 	/*
768 	 * Not all quirks can be derived from the cpufeatures device tree.
769 	 */
770 	if ((version & 0xffffefff) == 0x004e0200) {
771 		/* DD2.0 has no feature flag */
772 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_RADIX_PREFETCH_BUG;
773 		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
774 	} else if ((version & 0xffffefff) == 0x004e0201) {
775 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
776 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_RADIX_PREFETCH_BUG;
777 		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
778 	} else if ((version & 0xffffefff) == 0x004e0202) {
779 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
780 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
781 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
782 		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
783 	} else if ((version & 0xffffefff) == 0x004e0203) {
784 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
785 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
786 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
787 	} else if ((version & 0xffff0000) == 0x004e0000) {
788 		/* DD2.1 and up have DD2_1 */
789 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
790 	}
791 
792 	if ((version & 0xffff0000) == 0x004e0000) {
793 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TIDR;
794 	}
795 
796 	update_tlbie_feature_flag(version);
797 }
798 
799 static void __init cpufeatures_setup_finished(void)
800 {
801 	cpufeatures_cpu_quirks();
802 
803 	if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
804 		pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
805 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
806 	}
807 
808 	/* Make sure powerpc_base_platform is non-NULL */
809 	powerpc_base_platform = cur_cpu_spec->platform;
810 
811 	system_registers.lpcr = mfspr(SPRN_LPCR);
812 	system_registers.hfscr = mfspr(SPRN_HFSCR);
813 	system_registers.fscr = mfspr(SPRN_FSCR);
814 	system_registers.pcr = mfspr(SPRN_PCR);
815 
816 	pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
817 		cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
818 }
819 
820 static int __init disabled_on_cmdline(void)
821 {
822 	unsigned long root, chosen;
823 	const char *p;
824 
825 	root = of_get_flat_dt_root();
826 	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
827 	if (chosen == -FDT_ERR_NOTFOUND)
828 		return false;
829 
830 	p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
831 	if (!p)
832 		return false;
833 
834 	if (strstr(p, "dt_cpu_ftrs=off"))
835 		return true;
836 
837 	return false;
838 }
839 
840 static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
841 					int depth, void *data)
842 {
843 	if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
844 	    && of_get_flat_dt_prop(node, "isa", NULL))
845 		return 1;
846 
847 	return 0;
848 }
849 
850 bool __init dt_cpu_ftrs_in_use(void)
851 {
852 	return using_dt_cpu_ftrs;
853 }
854 
855 bool __init dt_cpu_ftrs_init(void *fdt)
856 {
857 	using_dt_cpu_ftrs = false;
858 
859 	/* Setup and verify the FDT, if it fails we just bail */
860 	if (!early_init_dt_verify(fdt))
861 		return false;
862 
863 	if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
864 		return false;
865 
866 	if (disabled_on_cmdline())
867 		return false;
868 
869 	cpufeatures_setup_cpu();
870 
871 	using_dt_cpu_ftrs = true;
872 	return true;
873 }
874 
875 static int nr_dt_cpu_features;
876 static struct dt_cpu_feature *dt_cpu_features;
877 
878 static int __init process_cpufeatures_node(unsigned long node,
879 					  const char *uname, int i)
880 {
881 	const __be32 *prop;
882 	struct dt_cpu_feature *f;
883 	int len;
884 
885 	f = &dt_cpu_features[i];
886 
887 	f->node = node;
888 
889 	f->name = uname;
890 
891 	prop = of_get_flat_dt_prop(node, "isa", &len);
892 	if (!prop) {
893 		pr_warn("%s: missing isa property\n", uname);
894 		return 0;
895 	}
896 	f->isa = be32_to_cpup(prop);
897 
898 	prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
899 	if (!prop) {
900 		pr_warn("%s: missing usable-privilege property", uname);
901 		return 0;
902 	}
903 	f->usable_privilege = be32_to_cpup(prop);
904 
905 	prop = of_get_flat_dt_prop(node, "hv-support", &len);
906 	if (prop)
907 		f->hv_support = be32_to_cpup(prop);
908 	else
909 		f->hv_support = HV_SUPPORT_NONE;
910 
911 	prop = of_get_flat_dt_prop(node, "os-support", &len);
912 	if (prop)
913 		f->os_support = be32_to_cpup(prop);
914 	else
915 		f->os_support = OS_SUPPORT_NONE;
916 
917 	prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
918 	if (prop)
919 		f->hfscr_bit_nr = be32_to_cpup(prop);
920 	else
921 		f->hfscr_bit_nr = -1;
922 	prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
923 	if (prop)
924 		f->fscr_bit_nr = be32_to_cpup(prop);
925 	else
926 		f->fscr_bit_nr = -1;
927 	prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
928 	if (prop)
929 		f->hwcap_bit_nr = be32_to_cpup(prop);
930 	else
931 		f->hwcap_bit_nr = -1;
932 
933 	if (f->usable_privilege & USABLE_HV) {
934 		if (!(mfmsr() & MSR_HV)) {
935 			pr_warn("%s: HV feature passed to guest\n", uname);
936 			return 0;
937 		}
938 
939 		if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
940 			pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
941 			return 0;
942 		}
943 
944 		if (f->hv_support == HV_SUPPORT_HFSCR) {
945 			if (f->hfscr_bit_nr == -1) {
946 				pr_warn("%s: missing hfscr_bit_nr\n", uname);
947 				return 0;
948 			}
949 		}
950 	} else {
951 		if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
952 			pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
953 			return 0;
954 		}
955 	}
956 
957 	if (f->usable_privilege & USABLE_OS) {
958 		if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
959 			pr_warn("%s: unwanted fscr_bit_nr\n", uname);
960 			return 0;
961 		}
962 
963 		if (f->os_support == OS_SUPPORT_FSCR) {
964 			if (f->fscr_bit_nr == -1) {
965 				pr_warn("%s: missing fscr_bit_nr\n", uname);
966 				return 0;
967 			}
968 		}
969 	} else {
970 		if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
971 			pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
972 			return 0;
973 		}
974 	}
975 
976 	if (!(f->usable_privilege & USABLE_PR)) {
977 		if (f->hwcap_bit_nr != -1) {
978 			pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
979 			return 0;
980 		}
981 	}
982 
983 	/* Do all the independent features in the first pass */
984 	if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
985 		if (cpufeatures_process_feature(f))
986 			f->enabled = 1;
987 		else
988 			f->disabled = 1;
989 	}
990 
991 	return 0;
992 }
993 
994 static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
995 {
996 	const __be32 *prop;
997 	int len;
998 	int nr_deps;
999 	int i;
1000 
1001 	if (f->enabled || f->disabled)
1002 		return;
1003 
1004 	prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
1005 	if (!prop) {
1006 		pr_warn("%s: missing dependencies property", f->name);
1007 		return;
1008 	}
1009 
1010 	nr_deps = len / sizeof(int);
1011 
1012 	for (i = 0; i < nr_deps; i++) {
1013 		unsigned long phandle = be32_to_cpu(prop[i]);
1014 		int j;
1015 
1016 		for (j = 0; j < nr_dt_cpu_features; j++) {
1017 			struct dt_cpu_feature *d = &dt_cpu_features[j];
1018 
1019 			if (of_get_flat_dt_phandle(d->node) == phandle) {
1020 				cpufeatures_deps_enable(d);
1021 				if (d->disabled) {
1022 					f->disabled = 1;
1023 					return;
1024 				}
1025 			}
1026 		}
1027 	}
1028 
1029 	if (cpufeatures_process_feature(f))
1030 		f->enabled = 1;
1031 	else
1032 		f->disabled = 1;
1033 }
1034 
1035 static int __init scan_cpufeatures_subnodes(unsigned long node,
1036 					  const char *uname,
1037 					  void *data)
1038 {
1039 	int *count = data;
1040 
1041 	process_cpufeatures_node(node, uname, *count);
1042 
1043 	(*count)++;
1044 
1045 	return 0;
1046 }
1047 
1048 static int __init count_cpufeatures_subnodes(unsigned long node,
1049 					  const char *uname,
1050 					  void *data)
1051 {
1052 	int *count = data;
1053 
1054 	(*count)++;
1055 
1056 	return 0;
1057 }
1058 
1059 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
1060 					    *uname, int depth, void *data)
1061 {
1062 	const __be32 *prop;
1063 	int count, i;
1064 	u32 isa;
1065 
1066 	/* We are scanning "ibm,powerpc-cpu-features" nodes only */
1067 	if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
1068 		return 0;
1069 
1070 	prop = of_get_flat_dt_prop(node, "isa", NULL);
1071 	if (!prop)
1072 		/* We checked before, "can't happen" */
1073 		return 0;
1074 
1075 	isa = be32_to_cpup(prop);
1076 
1077 	/* Count and allocate space for cpu features */
1078 	of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
1079 						&nr_dt_cpu_features);
1080 	dt_cpu_features = memblock_alloc(sizeof(struct dt_cpu_feature) * nr_dt_cpu_features, PAGE_SIZE);
1081 	if (!dt_cpu_features)
1082 		panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
1083 		      __func__,
1084 		      sizeof(struct dt_cpu_feature) * nr_dt_cpu_features,
1085 		      PAGE_SIZE);
1086 
1087 	cpufeatures_setup_start(isa);
1088 
1089 	/* Scan nodes into dt_cpu_features and enable those without deps  */
1090 	count = 0;
1091 	of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
1092 
1093 	/* Recursive enable remaining features with dependencies */
1094 	for (i = 0; i < nr_dt_cpu_features; i++) {
1095 		struct dt_cpu_feature *f = &dt_cpu_features[i];
1096 
1097 		cpufeatures_deps_enable(f);
1098 	}
1099 
1100 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
1101 	if (prop && strlen((char *)prop) != 0) {
1102 		strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
1103 		cur_cpu_spec->cpu_name = dt_cpu_name;
1104 	}
1105 
1106 	cpufeatures_setup_finished();
1107 
1108 	memblock_free(dt_cpu_features,
1109 		      sizeof(struct dt_cpu_feature) * nr_dt_cpu_features);
1110 
1111 	return 0;
1112 }
1113 
1114 void __init dt_cpu_ftrs_scan(void)
1115 {
1116 	if (!using_dt_cpu_ftrs)
1117 		return;
1118 
1119 	of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
1120 }
1121