1 /*
2  * Copyright 2017, Nicholas Piggin, IBM Corporation
3  * Licensed under GPLv2.
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/printk.h>
14 #include <linux/sched.h>
15 #include <linux/string.h>
16 #include <linux/threads.h>
17 
18 #include <asm/cputable.h>
19 #include <asm/dt_cpu_ftrs.h>
20 #include <asm/mmu.h>
21 #include <asm/oprofile_impl.h>
22 #include <asm/prom.h>
23 #include <asm/setup.h>
24 
25 
26 /* Device-tree visible constants follow */
27 #define ISA_V2_07B      2070
28 #define ISA_V3_0B       3000
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 CPU_FTRS_BASE \
57 	   (CPU_FTR_USE_TB | \
58 	    CPU_FTR_LWSYNC | \
59 	    CPU_FTR_FPU_UNAVAILABLE |\
60 	    CPU_FTR_NODSISRALIGN |\
61 	    CPU_FTR_NOEXECUTE |\
62 	    CPU_FTR_COHERENT_ICACHE | \
63 	    CPU_FTR_STCX_CHECKS_ADDRESS |\
64 	    CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
65 	    CPU_FTR_DAWR | \
66 	    CPU_FTR_ARCH_206 |\
67 	    CPU_FTR_ARCH_207S)
68 
69 #define MMU_FTRS_HASH_BASE (MMU_FTRS_POWER8)
70 
71 #define COMMON_USER_BASE	(PPC_FEATURE_32 | PPC_FEATURE_64 | \
72 				 PPC_FEATURE_ARCH_2_06 |\
73 				 PPC_FEATURE_ICACHE_SNOOP)
74 #define COMMON_USER2_BASE	(PPC_FEATURE2_ARCH_2_07 | \
75 				 PPC_FEATURE2_ISEL)
76 /*
77  * Set up the base CPU
78  */
79 
80 extern void __flush_tlb_power8(unsigned int action);
81 extern void __flush_tlb_power9(unsigned int action);
82 extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
83 extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
84 
85 static int hv_mode;
86 
87 static struct {
88 	u64	lpcr;
89 	u64	hfscr;
90 	u64	fscr;
91 } system_registers;
92 
93 static void (*init_pmu_registers)(void);
94 
95 static void cpufeatures_flush_tlb(void)
96 {
97 	/*
98 	 * This is a temporary measure to keep equivalent TLB flush as the
99 	 * cputable based setup code.
100 	 */
101 	switch (PVR_VER(mfspr(SPRN_PVR))) {
102 	case PVR_POWER8:
103 	case PVR_POWER8E:
104 	case PVR_POWER8NVL:
105 		__flush_tlb_power8(POWER8_TLB_SETS);
106 		break;
107 	case PVR_POWER9:
108 		__flush_tlb_power9(POWER9_TLB_SETS_HASH);
109 		break;
110 	default:
111 		pr_err("unknown CPU version for boot TLB flush\n");
112 		break;
113 	}
114 }
115 
116 static void __restore_cpu_cpufeatures(void)
117 {
118 	/*
119 	 * LPCR is restored by the power on engine already. It can be changed
120 	 * after early init e.g., by radix enable, and we have no unified API
121 	 * for saving and restoring such SPRs.
122 	 *
123 	 * This ->restore hook should really be removed from idle and register
124 	 * restore moved directly into the idle restore code, because this code
125 	 * doesn't know how idle is implemented or what it needs restored here.
126 	 *
127 	 * The best we can do to accommodate secondary boot and idle restore
128 	 * for now is "or" LPCR with existing.
129 	 */
130 
131 	mtspr(SPRN_LPCR, system_registers.lpcr | mfspr(SPRN_LPCR));
132 	if (hv_mode) {
133 		mtspr(SPRN_LPID, 0);
134 		mtspr(SPRN_HFSCR, system_registers.hfscr);
135 	}
136 	mtspr(SPRN_FSCR, system_registers.fscr);
137 
138 	if (init_pmu_registers)
139 		init_pmu_registers();
140 
141 	cpufeatures_flush_tlb();
142 }
143 
144 static char dt_cpu_name[64];
145 
146 static struct cpu_spec __initdata base_cpu_spec = {
147 	.cpu_name		= NULL,
148 	.cpu_features		= CPU_FTRS_BASE,
149 	.cpu_user_features	= COMMON_USER_BASE,
150 	.cpu_user_features2	= COMMON_USER2_BASE,
151 	.mmu_features		= 0,
152 	.icache_bsize		= 32, /* minimum block size, fixed by */
153 	.dcache_bsize		= 32, /* cache info init.             */
154 	.num_pmcs		= 0,
155 	.pmc_type		= PPC_PMC_DEFAULT,
156 	.oprofile_cpu_type	= NULL,
157 	.oprofile_type		= PPC_OPROFILE_INVALID,
158 	.cpu_setup		= NULL,
159 	.cpu_restore		= __restore_cpu_cpufeatures,
160 	.flush_tlb		= NULL,
161 	.machine_check_early	= NULL,
162 	.platform		= NULL,
163 };
164 
165 static void __init cpufeatures_setup_cpu(void)
166 {
167 	set_cur_cpu_spec(&base_cpu_spec);
168 
169 	cur_cpu_spec->pvr_mask = -1;
170 	cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
171 
172 	/* Initialize the base environment -- clear FSCR/HFSCR.  */
173 	hv_mode = !!(mfmsr() & MSR_HV);
174 	if (hv_mode) {
175 		/* CPU_FTR_HVMODE is used early in PACA setup */
176 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
177 		mtspr(SPRN_HFSCR, 0);
178 	}
179 	mtspr(SPRN_FSCR, 0);
180 
181 	/*
182 	 * LPCR does not get cleared, to match behaviour with secondaries
183 	 * in __restore_cpu_cpufeatures. Once the idle code is fixed, this
184 	 * could clear LPCR too.
185 	 */
186 }
187 
188 static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
189 {
190 	if (f->hv_support == HV_SUPPORT_NONE) {
191 	} else if (f->hv_support & HV_SUPPORT_HFSCR) {
192 		u64 hfscr = mfspr(SPRN_HFSCR);
193 		hfscr |= 1UL << f->hfscr_bit_nr;
194 		mtspr(SPRN_HFSCR, hfscr);
195 	} else {
196 		/* Does not have a known recipe */
197 		return 0;
198 	}
199 
200 	if (f->os_support == OS_SUPPORT_NONE) {
201 	} else if (f->os_support & OS_SUPPORT_FSCR) {
202 		u64 fscr = mfspr(SPRN_FSCR);
203 		fscr |= 1UL << f->fscr_bit_nr;
204 		mtspr(SPRN_FSCR, fscr);
205 	} else {
206 		/* Does not have a known recipe */
207 		return 0;
208 	}
209 
210 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
211 		uint32_t word = f->hwcap_bit_nr / 32;
212 		uint32_t bit = f->hwcap_bit_nr % 32;
213 
214 		if (word == 0)
215 			cur_cpu_spec->cpu_user_features |= 1U << bit;
216 		else if (word == 1)
217 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
218 		else
219 			pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
220 	}
221 
222 	return 1;
223 }
224 
225 static int __init feat_enable(struct dt_cpu_feature *f)
226 {
227 	if (f->hv_support != HV_SUPPORT_NONE) {
228 		if (f->hfscr_bit_nr != -1) {
229 			u64 hfscr = mfspr(SPRN_HFSCR);
230 			hfscr |= 1UL << f->hfscr_bit_nr;
231 			mtspr(SPRN_HFSCR, hfscr);
232 		}
233 	}
234 
235 	if (f->os_support != OS_SUPPORT_NONE) {
236 		if (f->fscr_bit_nr != -1) {
237 			u64 fscr = mfspr(SPRN_FSCR);
238 			fscr |= 1UL << f->fscr_bit_nr;
239 			mtspr(SPRN_FSCR, fscr);
240 		}
241 	}
242 
243 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
244 		uint32_t word = f->hwcap_bit_nr / 32;
245 		uint32_t bit = f->hwcap_bit_nr % 32;
246 
247 		if (word == 0)
248 			cur_cpu_spec->cpu_user_features |= 1U << bit;
249 		else if (word == 1)
250 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
251 		else
252 			pr_err("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
253 	}
254 
255 	return 1;
256 }
257 
258 static int __init feat_disable(struct dt_cpu_feature *f)
259 {
260 	return 0;
261 }
262 
263 static int __init feat_enable_hv(struct dt_cpu_feature *f)
264 {
265 	u64 lpcr;
266 
267 	if (!hv_mode) {
268 		pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
269 		return 0;
270 	}
271 
272 	mtspr(SPRN_LPID, 0);
273 
274 	lpcr = mfspr(SPRN_LPCR);
275 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
276 	mtspr(SPRN_LPCR, lpcr);
277 
278 	cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
279 
280 	return 1;
281 }
282 
283 static int __init feat_enable_le(struct dt_cpu_feature *f)
284 {
285 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
286 	return 1;
287 }
288 
289 static int __init feat_enable_smt(struct dt_cpu_feature *f)
290 {
291 	cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
292 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
293 	return 1;
294 }
295 
296 static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
297 {
298 	u64 lpcr;
299 
300 	/* Set PECE wakeup modes for ISA 207 */
301 	lpcr = mfspr(SPRN_LPCR);
302 	lpcr |=  LPCR_PECE0;
303 	lpcr |=  LPCR_PECE1;
304 	lpcr |=  LPCR_PECE2;
305 	mtspr(SPRN_LPCR, lpcr);
306 
307 	return 1;
308 }
309 
310 static int __init feat_enable_align_dsisr(struct dt_cpu_feature *f)
311 {
312 	cur_cpu_spec->cpu_features &= ~CPU_FTR_NODSISRALIGN;
313 
314 	return 1;
315 }
316 
317 static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
318 {
319 	u64 lpcr;
320 
321 	/* Set PECE wakeup modes for ISAv3.0B */
322 	lpcr = mfspr(SPRN_LPCR);
323 	lpcr |=  LPCR_PECE0;
324 	lpcr |=  LPCR_PECE1;
325 	lpcr |=  LPCR_PECE2;
326 	mtspr(SPRN_LPCR, lpcr);
327 
328 	return 1;
329 }
330 
331 static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
332 {
333 	u64 lpcr;
334 
335 	lpcr = mfspr(SPRN_LPCR);
336 	lpcr &= ~LPCR_ISL;
337 
338 	/* VRMASD */
339 	lpcr |= LPCR_VPM0;
340 	lpcr &= ~LPCR_VPM1;
341 	lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
342 	mtspr(SPRN_LPCR, lpcr);
343 
344 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
345 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
346 
347 	return 1;
348 }
349 
350 static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
351 {
352 	u64 lpcr;
353 
354 	lpcr = mfspr(SPRN_LPCR);
355 	lpcr &= ~LPCR_ISL;
356 	mtspr(SPRN_LPCR, lpcr);
357 
358 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
359 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
360 
361 	return 1;
362 }
363 
364 
365 static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
366 {
367 #ifdef CONFIG_PPC_RADIX_MMU
368 	cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
369 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
370 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
371 
372 	return 1;
373 #endif
374 	return 0;
375 }
376 
377 static int __init feat_enable_dscr(struct dt_cpu_feature *f)
378 {
379 	u64 lpcr;
380 
381 	feat_enable(f);
382 
383 	lpcr = mfspr(SPRN_LPCR);
384 	lpcr &= ~LPCR_DPFD;
385 	lpcr |=  (4UL << LPCR_DPFD_SH);
386 	mtspr(SPRN_LPCR, lpcr);
387 
388 	return 1;
389 }
390 
391 static void hfscr_pmu_enable(void)
392 {
393 	u64 hfscr = mfspr(SPRN_HFSCR);
394 	hfscr |= PPC_BIT(60);
395 	mtspr(SPRN_HFSCR, hfscr);
396 }
397 
398 static void init_pmu_power8(void)
399 {
400 	if (hv_mode) {
401 		mtspr(SPRN_MMCRC, 0);
402 		mtspr(SPRN_MMCRH, 0);
403 	}
404 
405 	mtspr(SPRN_MMCRA, 0);
406 	mtspr(SPRN_MMCR0, 0);
407 	mtspr(SPRN_MMCR1, 0);
408 	mtspr(SPRN_MMCR2, 0);
409 	mtspr(SPRN_MMCRS, 0);
410 }
411 
412 static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
413 {
414 	cur_cpu_spec->platform = "power8";
415 	cur_cpu_spec->flush_tlb = __flush_tlb_power8;
416 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
417 
418 	return 1;
419 }
420 
421 static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
422 {
423 	hfscr_pmu_enable();
424 
425 	init_pmu_power8();
426 	init_pmu_registers = init_pmu_power8;
427 
428 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
429 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
430 	if (pvr_version_is(PVR_POWER8E))
431 		cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
432 
433 	cur_cpu_spec->num_pmcs		= 6;
434 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
435 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power8";
436 
437 	return 1;
438 }
439 
440 static void init_pmu_power9(void)
441 {
442 	if (hv_mode)
443 		mtspr(SPRN_MMCRC, 0);
444 
445 	mtspr(SPRN_MMCRA, 0);
446 	mtspr(SPRN_MMCR0, 0);
447 	mtspr(SPRN_MMCR1, 0);
448 	mtspr(SPRN_MMCR2, 0);
449 }
450 
451 static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
452 {
453 	cur_cpu_spec->platform = "power9";
454 	cur_cpu_spec->flush_tlb = __flush_tlb_power9;
455 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
456 
457 	return 1;
458 }
459 
460 static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
461 {
462 	hfscr_pmu_enable();
463 
464 	init_pmu_power9();
465 	init_pmu_registers = init_pmu_power9;
466 
467 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
468 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
469 
470 	cur_cpu_spec->num_pmcs		= 6;
471 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
472 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power9";
473 
474 	return 1;
475 }
476 
477 static int __init feat_enable_tm(struct dt_cpu_feature *f)
478 {
479 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
480 	feat_enable(f);
481 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
482 	return 1;
483 #endif
484 	return 0;
485 }
486 
487 static int __init feat_enable_fp(struct dt_cpu_feature *f)
488 {
489 	feat_enable(f);
490 	cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
491 
492 	return 1;
493 }
494 
495 static int __init feat_enable_vector(struct dt_cpu_feature *f)
496 {
497 #ifdef CONFIG_ALTIVEC
498 	feat_enable(f);
499 	cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
500 	cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
501 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
502 
503 	return 1;
504 #endif
505 	return 0;
506 }
507 
508 static int __init feat_enable_vsx(struct dt_cpu_feature *f)
509 {
510 #ifdef CONFIG_VSX
511 	feat_enable(f);
512 	cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
513 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
514 
515 	return 1;
516 #endif
517 	return 0;
518 }
519 
520 static int __init feat_enable_purr(struct dt_cpu_feature *f)
521 {
522 	cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
523 
524 	return 1;
525 }
526 
527 static int __init feat_enable_ebb(struct dt_cpu_feature *f)
528 {
529 	/*
530 	 * PPC_FEATURE2_EBB is enabled in PMU init code because it has
531 	 * historically been related to the PMU facility. This may have
532 	 * to be decoupled if EBB becomes more generic. For now, follow
533 	 * existing convention.
534 	 */
535 	f->hwcap_bit_nr = -1;
536 	feat_enable(f);
537 
538 	return 1;
539 }
540 
541 static int __init feat_enable_dbell(struct dt_cpu_feature *f)
542 {
543 	u64 lpcr;
544 
545 	/* P9 has an HFSCR for privileged state */
546 	feat_enable(f);
547 
548 	cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
549 
550 	lpcr = mfspr(SPRN_LPCR);
551 	lpcr |=  LPCR_PECEDH; /* hyp doorbell wakeup */
552 	mtspr(SPRN_LPCR, lpcr);
553 
554 	return 1;
555 }
556 
557 static int __init feat_enable_hvi(struct dt_cpu_feature *f)
558 {
559 	u64 lpcr;
560 
561 	/*
562 	 * POWER9 XIVE interrupts including in OPAL XICS compatibility
563 	 * are always delivered as hypervisor virtualization interrupts (HVI)
564 	 * rather than EE.
565 	 *
566 	 * However LPES0 is not set here, in the chance that an EE does get
567 	 * delivered to the host somehow, the EE handler would not expect it
568 	 * to be delivered in LPES0 mode (e.g., using SRR[01]). This could
569 	 * happen if there is a bug in interrupt controller code, or IC is
570 	 * misconfigured in systemsim.
571 	 */
572 
573 	lpcr = mfspr(SPRN_LPCR);
574 	lpcr |= LPCR_HVICE;	/* enable hvi interrupts */
575 	lpcr |= LPCR_HEIC;	/* disable ee interrupts when MSR_HV */
576 	lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
577 	mtspr(SPRN_LPCR, lpcr);
578 
579 	return 1;
580 }
581 
582 static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
583 {
584 	cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
585 
586 	return 1;
587 }
588 
589 struct dt_cpu_feature_match {
590 	const char *name;
591 	int (*enable)(struct dt_cpu_feature *f);
592 	u64 cpu_ftr_bit_mask;
593 };
594 
595 static struct dt_cpu_feature_match __initdata
596 		dt_cpu_feature_match_table[] = {
597 	{"hypervisor", feat_enable_hv, 0},
598 	{"big-endian", feat_enable, 0},
599 	{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
600 	{"smt", feat_enable_smt, 0},
601 	{"interrupt-facilities", feat_enable, 0},
602 	{"timer-facilities", feat_enable, 0},
603 	{"timer-facilities-v3", feat_enable, 0},
604 	{"debug-facilities", feat_enable, 0},
605 	{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
606 	{"branch-tracing", feat_enable, 0},
607 	{"floating-point", feat_enable_fp, 0},
608 	{"vector", feat_enable_vector, 0},
609 	{"vector-scalar", feat_enable_vsx, 0},
610 	{"vector-scalar-v3", feat_enable, 0},
611 	{"decimal-floating-point", feat_enable, 0},
612 	{"decimal-integer", feat_enable, 0},
613 	{"quadword-load-store", feat_enable, 0},
614 	{"vector-crypto", feat_enable, 0},
615 	{"mmu-hash", feat_enable_mmu_hash, 0},
616 	{"mmu-radix", feat_enable_mmu_radix, 0},
617 	{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
618 	{"virtual-page-class-key-protection", feat_enable, 0},
619 	{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
620 	{"transactional-memory-v3", feat_enable_tm, 0},
621 	{"idle-nap", feat_enable_idle_nap, 0},
622 	{"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0},
623 	{"idle-stop", feat_enable_idle_stop, 0},
624 	{"machine-check-power8", feat_enable_mce_power8, 0},
625 	{"performance-monitor-power8", feat_enable_pmu_power8, 0},
626 	{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
627 	{"event-based-branch", feat_enable_ebb, 0},
628 	{"target-address-register", feat_enable, 0},
629 	{"branch-history-rolling-buffer", feat_enable, 0},
630 	{"control-register", feat_enable, CPU_FTR_CTRL},
631 	{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
632 	{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
633 	{"processor-utilization-of-resources-register", feat_enable_purr, 0},
634 	{"no-execute", feat_enable, 0},
635 	{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
636 	{"cache-inhibited-large-page", feat_enable_large_ci, 0},
637 	{"coprocessor-icswx", feat_enable, CPU_FTR_ICSWX},
638 	{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
639 	{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
640 	{"wait", feat_enable, 0},
641 	{"atomic-memory-operations", feat_enable, 0},
642 	{"branch-v3", feat_enable, 0},
643 	{"copy-paste", feat_enable, 0},
644 	{"decimal-floating-point-v3", feat_enable, 0},
645 	{"decimal-integer-v3", feat_enable, 0},
646 	{"fixed-point-v3", feat_enable, 0},
647 	{"floating-point-v3", feat_enable, 0},
648 	{"group-start-register", feat_enable, 0},
649 	{"pc-relative-addressing", feat_enable, 0},
650 	{"machine-check-power9", feat_enable_mce_power9, 0},
651 	{"performance-monitor-power9", feat_enable_pmu_power9, 0},
652 	{"event-based-branch-v3", feat_enable, 0},
653 	{"random-number-generator", feat_enable, 0},
654 	{"system-call-vectored", feat_disable, 0},
655 	{"trace-interrupt-v3", feat_enable, 0},
656 	{"vector-v3", feat_enable, 0},
657 	{"vector-binary128", feat_enable, 0},
658 	{"vector-binary16", feat_enable, 0},
659 	{"wait-v3", feat_enable, 0},
660 };
661 
662 static bool __initdata using_dt_cpu_ftrs;
663 static bool __initdata enable_unknown = true;
664 
665 static int __init dt_cpu_ftrs_parse(char *str)
666 {
667 	if (!str)
668 		return 0;
669 
670 	if (!strcmp(str, "off"))
671 		using_dt_cpu_ftrs = false;
672 	else if (!strcmp(str, "known"))
673 		enable_unknown = false;
674 	else
675 		return 1;
676 
677 	return 0;
678 }
679 early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
680 
681 static void __init cpufeatures_setup_start(u32 isa)
682 {
683 	pr_info("setup for ISA %d\n", isa);
684 
685 	if (isa >= 3000) {
686 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
687 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
688 	}
689 }
690 
691 static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
692 {
693 	const struct dt_cpu_feature_match *m;
694 	bool known = false;
695 	int i;
696 
697 	for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
698 		m = &dt_cpu_feature_match_table[i];
699 		if (!strcmp(f->name, m->name)) {
700 			known = true;
701 			if (m->enable(f))
702 				break;
703 
704 			pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
705 				f->name);
706 			return false;
707 		}
708 	}
709 
710 	if (!known && enable_unknown) {
711 		if (!feat_try_enable_unknown(f)) {
712 			pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
713 				f->name);
714 			return false;
715 		}
716 	}
717 
718 	if (m->cpu_ftr_bit_mask)
719 		cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
720 
721 	if (known)
722 		pr_debug("enabling: %s\n", f->name);
723 	else
724 		pr_debug("enabling: %s (unknown)\n", f->name);
725 
726 	return true;
727 }
728 
729 static __init void cpufeatures_cpu_quirks(void)
730 {
731 	int version = mfspr(SPRN_PVR);
732 
733 	/*
734 	 * Not all quirks can be derived from the cpufeatures device tree.
735 	 */
736 	if ((version & 0xffffff00) == 0x004e0100)
737 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD1;
738 }
739 
740 static void __init cpufeatures_setup_finished(void)
741 {
742 	cpufeatures_cpu_quirks();
743 
744 	if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
745 		pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
746 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
747 	}
748 
749 	system_registers.lpcr = mfspr(SPRN_LPCR);
750 	system_registers.hfscr = mfspr(SPRN_HFSCR);
751 	system_registers.fscr = mfspr(SPRN_FSCR);
752 
753 	cpufeatures_flush_tlb();
754 
755 	pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
756 		cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
757 }
758 
759 static int __init disabled_on_cmdline(void)
760 {
761 	unsigned long root, chosen;
762 	const char *p;
763 
764 	root = of_get_flat_dt_root();
765 	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
766 	if (chosen == -FDT_ERR_NOTFOUND)
767 		return false;
768 
769 	p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
770 	if (!p)
771 		return false;
772 
773 	if (strstr(p, "dt_cpu_ftrs=off"))
774 		return true;
775 
776 	return false;
777 }
778 
779 static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
780 					int depth, void *data)
781 {
782 	if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
783 	    && of_get_flat_dt_prop(node, "isa", NULL))
784 		return 1;
785 
786 	return 0;
787 }
788 
789 bool __init dt_cpu_ftrs_in_use(void)
790 {
791 	return using_dt_cpu_ftrs;
792 }
793 
794 bool __init dt_cpu_ftrs_init(void *fdt)
795 {
796 	using_dt_cpu_ftrs = false;
797 
798 	/* Setup and verify the FDT, if it fails we just bail */
799 	if (!early_init_dt_verify(fdt))
800 		return false;
801 
802 	if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
803 		return false;
804 
805 	if (disabled_on_cmdline())
806 		return false;
807 
808 	cpufeatures_setup_cpu();
809 
810 	using_dt_cpu_ftrs = true;
811 	return true;
812 }
813 
814 static int nr_dt_cpu_features;
815 static struct dt_cpu_feature *dt_cpu_features;
816 
817 static int __init process_cpufeatures_node(unsigned long node,
818 					  const char *uname, int i)
819 {
820 	const __be32 *prop;
821 	struct dt_cpu_feature *f;
822 	int len;
823 
824 	f = &dt_cpu_features[i];
825 	memset(f, 0, sizeof(struct dt_cpu_feature));
826 
827 	f->node = node;
828 
829 	f->name = uname;
830 
831 	prop = of_get_flat_dt_prop(node, "isa", &len);
832 	if (!prop) {
833 		pr_warn("%s: missing isa property\n", uname);
834 		return 0;
835 	}
836 	f->isa = be32_to_cpup(prop);
837 
838 	prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
839 	if (!prop) {
840 		pr_warn("%s: missing usable-privilege property", uname);
841 		return 0;
842 	}
843 	f->usable_privilege = be32_to_cpup(prop);
844 
845 	prop = of_get_flat_dt_prop(node, "hv-support", &len);
846 	if (prop)
847 		f->hv_support = be32_to_cpup(prop);
848 	else
849 		f->hv_support = HV_SUPPORT_NONE;
850 
851 	prop = of_get_flat_dt_prop(node, "os-support", &len);
852 	if (prop)
853 		f->os_support = be32_to_cpup(prop);
854 	else
855 		f->os_support = OS_SUPPORT_NONE;
856 
857 	prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
858 	if (prop)
859 		f->hfscr_bit_nr = be32_to_cpup(prop);
860 	else
861 		f->hfscr_bit_nr = -1;
862 	prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
863 	if (prop)
864 		f->fscr_bit_nr = be32_to_cpup(prop);
865 	else
866 		f->fscr_bit_nr = -1;
867 	prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
868 	if (prop)
869 		f->hwcap_bit_nr = be32_to_cpup(prop);
870 	else
871 		f->hwcap_bit_nr = -1;
872 
873 	if (f->usable_privilege & USABLE_HV) {
874 		if (!(mfmsr() & MSR_HV)) {
875 			pr_warn("%s: HV feature passed to guest\n", uname);
876 			return 0;
877 		}
878 
879 		if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
880 			pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
881 			return 0;
882 		}
883 
884 		if (f->hv_support == HV_SUPPORT_HFSCR) {
885 			if (f->hfscr_bit_nr == -1) {
886 				pr_warn("%s: missing hfscr_bit_nr\n", uname);
887 				return 0;
888 			}
889 		}
890 	} else {
891 		if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
892 			pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
893 			return 0;
894 		}
895 	}
896 
897 	if (f->usable_privilege & USABLE_OS) {
898 		if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
899 			pr_warn("%s: unwanted fscr_bit_nr\n", uname);
900 			return 0;
901 		}
902 
903 		if (f->os_support == OS_SUPPORT_FSCR) {
904 			if (f->fscr_bit_nr == -1) {
905 				pr_warn("%s: missing fscr_bit_nr\n", uname);
906 				return 0;
907 			}
908 		}
909 	} else {
910 		if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
911 			pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
912 			return 0;
913 		}
914 	}
915 
916 	if (!(f->usable_privilege & USABLE_PR)) {
917 		if (f->hwcap_bit_nr != -1) {
918 			pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
919 			return 0;
920 		}
921 	}
922 
923 	/* Do all the independent features in the first pass */
924 	if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
925 		if (cpufeatures_process_feature(f))
926 			f->enabled = 1;
927 		else
928 			f->disabled = 1;
929 	}
930 
931 	return 0;
932 }
933 
934 static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
935 {
936 	const __be32 *prop;
937 	int len;
938 	int nr_deps;
939 	int i;
940 
941 	if (f->enabled || f->disabled)
942 		return;
943 
944 	prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
945 	if (!prop) {
946 		pr_warn("%s: missing dependencies property", f->name);
947 		return;
948 	}
949 
950 	nr_deps = len / sizeof(int);
951 
952 	for (i = 0; i < nr_deps; i++) {
953 		unsigned long phandle = be32_to_cpu(prop[i]);
954 		int j;
955 
956 		for (j = 0; j < nr_dt_cpu_features; j++) {
957 			struct dt_cpu_feature *d = &dt_cpu_features[j];
958 
959 			if (of_get_flat_dt_phandle(d->node) == phandle) {
960 				cpufeatures_deps_enable(d);
961 				if (d->disabled) {
962 					f->disabled = 1;
963 					return;
964 				}
965 			}
966 		}
967 	}
968 
969 	if (cpufeatures_process_feature(f))
970 		f->enabled = 1;
971 	else
972 		f->disabled = 1;
973 }
974 
975 static int __init scan_cpufeatures_subnodes(unsigned long node,
976 					  const char *uname,
977 					  void *data)
978 {
979 	int *count = data;
980 
981 	process_cpufeatures_node(node, uname, *count);
982 
983 	(*count)++;
984 
985 	return 0;
986 }
987 
988 static int __init count_cpufeatures_subnodes(unsigned long node,
989 					  const char *uname,
990 					  void *data)
991 {
992 	int *count = data;
993 
994 	(*count)++;
995 
996 	return 0;
997 }
998 
999 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
1000 					    *uname, int depth, void *data)
1001 {
1002 	const __be32 *prop;
1003 	int count, i;
1004 	u32 isa;
1005 
1006 	/* We are scanning "ibm,powerpc-cpu-features" nodes only */
1007 	if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
1008 		return 0;
1009 
1010 	prop = of_get_flat_dt_prop(node, "isa", NULL);
1011 	if (!prop)
1012 		/* We checked before, "can't happen" */
1013 		return 0;
1014 
1015 	isa = be32_to_cpup(prop);
1016 
1017 	/* Count and allocate space for cpu features */
1018 	of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
1019 						&nr_dt_cpu_features);
1020 	dt_cpu_features = __va(
1021 		memblock_alloc(sizeof(struct dt_cpu_feature)*
1022 				nr_dt_cpu_features, PAGE_SIZE));
1023 
1024 	cpufeatures_setup_start(isa);
1025 
1026 	/* Scan nodes into dt_cpu_features and enable those without deps  */
1027 	count = 0;
1028 	of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
1029 
1030 	/* Recursive enable remaining features with dependencies */
1031 	for (i = 0; i < nr_dt_cpu_features; i++) {
1032 		struct dt_cpu_feature *f = &dt_cpu_features[i];
1033 
1034 		cpufeatures_deps_enable(f);
1035 	}
1036 
1037 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
1038 	if (prop && strlen((char *)prop) != 0) {
1039 		strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
1040 		cur_cpu_spec->cpu_name = dt_cpu_name;
1041 	}
1042 
1043 	cpufeatures_setup_finished();
1044 
1045 	memblock_free(__pa(dt_cpu_features),
1046 			sizeof(struct dt_cpu_feature)*nr_dt_cpu_features);
1047 
1048 	return 0;
1049 }
1050 
1051 void __init dt_cpu_ftrs_scan(void)
1052 {
1053 	if (!using_dt_cpu_ftrs)
1054 		return;
1055 
1056 	of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
1057 }
1058