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 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 extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
68 extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
69 
70 static int hv_mode;
71 
72 static struct {
73 	u64	lpcr;
74 	u64	lpcr_clear;
75 	u64	hfscr;
76 	u64	fscr;
77 } system_registers;
78 
79 static void (*init_pmu_registers)(void);
80 
81 static void __restore_cpu_cpufeatures(void)
82 {
83 	u64 lpcr;
84 
85 	/*
86 	 * LPCR is restored by the power on engine already. It can be changed
87 	 * after early init e.g., by radix enable, and we have no unified API
88 	 * for saving and restoring such SPRs.
89 	 *
90 	 * This ->restore hook should really be removed from idle and register
91 	 * restore moved directly into the idle restore code, because this code
92 	 * doesn't know how idle is implemented or what it needs restored here.
93 	 *
94 	 * The best we can do to accommodate secondary boot and idle restore
95 	 * for now is "or" LPCR with existing.
96 	 */
97 	lpcr = mfspr(SPRN_LPCR);
98 	lpcr |= system_registers.lpcr;
99 	lpcr &= ~system_registers.lpcr_clear;
100 	mtspr(SPRN_LPCR, lpcr);
101 	if (hv_mode) {
102 		mtspr(SPRN_LPID, 0);
103 		mtspr(SPRN_HFSCR, system_registers.hfscr);
104 		mtspr(SPRN_PCR, 0);
105 	}
106 	mtspr(SPRN_FSCR, system_registers.fscr);
107 
108 	if (init_pmu_registers)
109 		init_pmu_registers();
110 }
111 
112 static char dt_cpu_name[64];
113 
114 static struct cpu_spec __initdata base_cpu_spec = {
115 	.cpu_name		= NULL,
116 	.cpu_features		= CPU_FTRS_DT_CPU_BASE,
117 	.cpu_user_features	= COMMON_USER_BASE,
118 	.cpu_user_features2	= COMMON_USER2_BASE,
119 	.mmu_features		= 0,
120 	.icache_bsize		= 32, /* minimum block size, fixed by */
121 	.dcache_bsize		= 32, /* cache info init.             */
122 	.num_pmcs		= 0,
123 	.pmc_type		= PPC_PMC_DEFAULT,
124 	.oprofile_cpu_type	= NULL,
125 	.oprofile_type		= PPC_OPROFILE_INVALID,
126 	.cpu_setup		= NULL,
127 	.cpu_restore		= __restore_cpu_cpufeatures,
128 	.machine_check_early	= NULL,
129 	.platform		= NULL,
130 };
131 
132 static void __init cpufeatures_setup_cpu(void)
133 {
134 	set_cur_cpu_spec(&base_cpu_spec);
135 
136 	cur_cpu_spec->pvr_mask = -1;
137 	cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
138 
139 	/* Initialize the base environment -- clear FSCR/HFSCR.  */
140 	hv_mode = !!(mfmsr() & MSR_HV);
141 	if (hv_mode) {
142 		/* CPU_FTR_HVMODE is used early in PACA setup */
143 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
144 		mtspr(SPRN_HFSCR, 0);
145 	}
146 	mtspr(SPRN_FSCR, 0);
147 
148 	/*
149 	 * LPCR does not get cleared, to match behaviour with secondaries
150 	 * in __restore_cpu_cpufeatures. Once the idle code is fixed, this
151 	 * could clear LPCR too.
152 	 */
153 }
154 
155 static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
156 {
157 	if (f->hv_support == HV_SUPPORT_NONE) {
158 	} else if (f->hv_support & HV_SUPPORT_HFSCR) {
159 		u64 hfscr = mfspr(SPRN_HFSCR);
160 		hfscr |= 1UL << f->hfscr_bit_nr;
161 		mtspr(SPRN_HFSCR, hfscr);
162 	} else {
163 		/* Does not have a known recipe */
164 		return 0;
165 	}
166 
167 	if (f->os_support == OS_SUPPORT_NONE) {
168 	} else if (f->os_support & OS_SUPPORT_FSCR) {
169 		u64 fscr = mfspr(SPRN_FSCR);
170 		fscr |= 1UL << f->fscr_bit_nr;
171 		mtspr(SPRN_FSCR, fscr);
172 	} else {
173 		/* Does not have a known recipe */
174 		return 0;
175 	}
176 
177 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
178 		uint32_t word = f->hwcap_bit_nr / 32;
179 		uint32_t bit = f->hwcap_bit_nr % 32;
180 
181 		if (word == 0)
182 			cur_cpu_spec->cpu_user_features |= 1U << bit;
183 		else if (word == 1)
184 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
185 		else
186 			pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
187 	}
188 
189 	return 1;
190 }
191 
192 static int __init feat_enable(struct dt_cpu_feature *f)
193 {
194 	if (f->hv_support != HV_SUPPORT_NONE) {
195 		if (f->hfscr_bit_nr != -1) {
196 			u64 hfscr = mfspr(SPRN_HFSCR);
197 			hfscr |= 1UL << f->hfscr_bit_nr;
198 			mtspr(SPRN_HFSCR, hfscr);
199 		}
200 	}
201 
202 	if (f->os_support != OS_SUPPORT_NONE) {
203 		if (f->fscr_bit_nr != -1) {
204 			u64 fscr = mfspr(SPRN_FSCR);
205 			fscr |= 1UL << f->fscr_bit_nr;
206 			mtspr(SPRN_FSCR, fscr);
207 		}
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("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
220 	}
221 
222 	return 1;
223 }
224 
225 static int __init feat_disable(struct dt_cpu_feature *f)
226 {
227 	return 0;
228 }
229 
230 static int __init feat_enable_hv(struct dt_cpu_feature *f)
231 {
232 	u64 lpcr;
233 
234 	if (!hv_mode) {
235 		pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
236 		return 0;
237 	}
238 
239 	mtspr(SPRN_LPID, 0);
240 
241 	lpcr = mfspr(SPRN_LPCR);
242 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
243 	mtspr(SPRN_LPCR, lpcr);
244 
245 	cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
246 
247 	return 1;
248 }
249 
250 static int __init feat_enable_le(struct dt_cpu_feature *f)
251 {
252 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
253 	return 1;
254 }
255 
256 static int __init feat_enable_smt(struct dt_cpu_feature *f)
257 {
258 	cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
259 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
260 	return 1;
261 }
262 
263 static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
264 {
265 	u64 lpcr;
266 
267 	/* Set PECE wakeup modes for ISA 207 */
268 	lpcr = mfspr(SPRN_LPCR);
269 	lpcr |=  LPCR_PECE0;
270 	lpcr |=  LPCR_PECE1;
271 	lpcr |=  LPCR_PECE2;
272 	mtspr(SPRN_LPCR, lpcr);
273 
274 	return 1;
275 }
276 
277 static int __init feat_enable_align_dsisr(struct dt_cpu_feature *f)
278 {
279 	cur_cpu_spec->cpu_features &= ~CPU_FTR_NODSISRALIGN;
280 
281 	return 1;
282 }
283 
284 static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
285 {
286 	u64 lpcr;
287 
288 	/* Set PECE wakeup modes for ISAv3.0B */
289 	lpcr = mfspr(SPRN_LPCR);
290 	lpcr |=  LPCR_PECE0;
291 	lpcr |=  LPCR_PECE1;
292 	lpcr |=  LPCR_PECE2;
293 	mtspr(SPRN_LPCR, lpcr);
294 
295 	return 1;
296 }
297 
298 static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
299 {
300 	u64 lpcr;
301 
302 	lpcr = mfspr(SPRN_LPCR);
303 	lpcr &= ~LPCR_ISL;
304 
305 	/* VRMASD */
306 	lpcr |= LPCR_VPM0;
307 	lpcr &= ~LPCR_VPM1;
308 	lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
309 	mtspr(SPRN_LPCR, lpcr);
310 
311 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
312 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
313 
314 	return 1;
315 }
316 
317 static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
318 {
319 	u64 lpcr;
320 
321 	system_registers.lpcr_clear |= (LPCR_ISL | LPCR_UPRT | LPCR_HR);
322 	lpcr = mfspr(SPRN_LPCR);
323 	lpcr &= ~(LPCR_ISL | LPCR_UPRT | LPCR_HR);
324 	mtspr(SPRN_LPCR, lpcr);
325 
326 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
327 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
328 
329 	return 1;
330 }
331 
332 
333 static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
334 {
335 #ifdef CONFIG_PPC_RADIX_MMU
336 	cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
337 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
338 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
339 
340 	return 1;
341 #endif
342 	return 0;
343 }
344 
345 static int __init feat_enable_dscr(struct dt_cpu_feature *f)
346 {
347 	u64 lpcr;
348 
349 	feat_enable(f);
350 
351 	lpcr = mfspr(SPRN_LPCR);
352 	lpcr &= ~LPCR_DPFD;
353 	lpcr |=  (4UL << LPCR_DPFD_SH);
354 	mtspr(SPRN_LPCR, lpcr);
355 
356 	return 1;
357 }
358 
359 static void hfscr_pmu_enable(void)
360 {
361 	u64 hfscr = mfspr(SPRN_HFSCR);
362 	hfscr |= PPC_BIT(60);
363 	mtspr(SPRN_HFSCR, hfscr);
364 }
365 
366 static void init_pmu_power8(void)
367 {
368 	if (hv_mode) {
369 		mtspr(SPRN_MMCRC, 0);
370 		mtspr(SPRN_MMCRH, 0);
371 	}
372 
373 	mtspr(SPRN_MMCRA, 0);
374 	mtspr(SPRN_MMCR0, 0);
375 	mtspr(SPRN_MMCR1, 0);
376 	mtspr(SPRN_MMCR2, 0);
377 	mtspr(SPRN_MMCRS, 0);
378 }
379 
380 static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
381 {
382 	cur_cpu_spec->platform = "power8";
383 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
384 
385 	return 1;
386 }
387 
388 static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
389 {
390 	hfscr_pmu_enable();
391 
392 	init_pmu_power8();
393 	init_pmu_registers = init_pmu_power8;
394 
395 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
396 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
397 	if (pvr_version_is(PVR_POWER8E))
398 		cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
399 
400 	cur_cpu_spec->num_pmcs		= 6;
401 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
402 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power8";
403 
404 	return 1;
405 }
406 
407 static void init_pmu_power9(void)
408 {
409 	if (hv_mode)
410 		mtspr(SPRN_MMCRC, 0);
411 
412 	mtspr(SPRN_MMCRA, 0);
413 	mtspr(SPRN_MMCR0, 0);
414 	mtspr(SPRN_MMCR1, 0);
415 	mtspr(SPRN_MMCR2, 0);
416 }
417 
418 static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
419 {
420 	cur_cpu_spec->platform = "power9";
421 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
422 
423 	return 1;
424 }
425 
426 static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
427 {
428 	hfscr_pmu_enable();
429 
430 	init_pmu_power9();
431 	init_pmu_registers = init_pmu_power9;
432 
433 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
434 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
435 
436 	cur_cpu_spec->num_pmcs		= 6;
437 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
438 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power9";
439 
440 	return 1;
441 }
442 
443 static int __init feat_enable_tm(struct dt_cpu_feature *f)
444 {
445 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
446 	feat_enable(f);
447 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
448 	return 1;
449 #endif
450 	return 0;
451 }
452 
453 static int __init feat_enable_fp(struct dt_cpu_feature *f)
454 {
455 	feat_enable(f);
456 	cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
457 
458 	return 1;
459 }
460 
461 static int __init feat_enable_vector(struct dt_cpu_feature *f)
462 {
463 #ifdef CONFIG_ALTIVEC
464 	feat_enable(f);
465 	cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
466 	cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
467 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
468 
469 	return 1;
470 #endif
471 	return 0;
472 }
473 
474 static int __init feat_enable_vsx(struct dt_cpu_feature *f)
475 {
476 #ifdef CONFIG_VSX
477 	feat_enable(f);
478 	cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
479 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
480 
481 	return 1;
482 #endif
483 	return 0;
484 }
485 
486 static int __init feat_enable_purr(struct dt_cpu_feature *f)
487 {
488 	cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
489 
490 	return 1;
491 }
492 
493 static int __init feat_enable_ebb(struct dt_cpu_feature *f)
494 {
495 	/*
496 	 * PPC_FEATURE2_EBB is enabled in PMU init code because it has
497 	 * historically been related to the PMU facility. This may have
498 	 * to be decoupled if EBB becomes more generic. For now, follow
499 	 * existing convention.
500 	 */
501 	f->hwcap_bit_nr = -1;
502 	feat_enable(f);
503 
504 	return 1;
505 }
506 
507 static int __init feat_enable_dbell(struct dt_cpu_feature *f)
508 {
509 	u64 lpcr;
510 
511 	/* P9 has an HFSCR for privileged state */
512 	feat_enable(f);
513 
514 	cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
515 
516 	lpcr = mfspr(SPRN_LPCR);
517 	lpcr |=  LPCR_PECEDH; /* hyp doorbell wakeup */
518 	mtspr(SPRN_LPCR, lpcr);
519 
520 	return 1;
521 }
522 
523 static int __init feat_enable_hvi(struct dt_cpu_feature *f)
524 {
525 	u64 lpcr;
526 
527 	/*
528 	 * POWER9 XIVE interrupts including in OPAL XICS compatibility
529 	 * are always delivered as hypervisor virtualization interrupts (HVI)
530 	 * rather than EE.
531 	 *
532 	 * However LPES0 is not set here, in the chance that an EE does get
533 	 * delivered to the host somehow, the EE handler would not expect it
534 	 * to be delivered in LPES0 mode (e.g., using SRR[01]). This could
535 	 * happen if there is a bug in interrupt controller code, or IC is
536 	 * misconfigured in systemsim.
537 	 */
538 
539 	lpcr = mfspr(SPRN_LPCR);
540 	lpcr |= LPCR_HVICE;	/* enable hvi interrupts */
541 	lpcr |= LPCR_HEIC;	/* disable ee interrupts when MSR_HV */
542 	lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
543 	mtspr(SPRN_LPCR, lpcr);
544 
545 	return 1;
546 }
547 
548 static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
549 {
550 	cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
551 
552 	return 1;
553 }
554 
555 struct dt_cpu_feature_match {
556 	const char *name;
557 	int (*enable)(struct dt_cpu_feature *f);
558 	u64 cpu_ftr_bit_mask;
559 };
560 
561 static struct dt_cpu_feature_match __initdata
562 		dt_cpu_feature_match_table[] = {
563 	{"hypervisor", feat_enable_hv, 0},
564 	{"big-endian", feat_enable, 0},
565 	{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
566 	{"smt", feat_enable_smt, 0},
567 	{"interrupt-facilities", feat_enable, 0},
568 	{"timer-facilities", feat_enable, 0},
569 	{"timer-facilities-v3", feat_enable, 0},
570 	{"debug-facilities", feat_enable, 0},
571 	{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
572 	{"branch-tracing", feat_enable, 0},
573 	{"floating-point", feat_enable_fp, 0},
574 	{"vector", feat_enable_vector, 0},
575 	{"vector-scalar", feat_enable_vsx, 0},
576 	{"vector-scalar-v3", feat_enable, 0},
577 	{"decimal-floating-point", feat_enable, 0},
578 	{"decimal-integer", feat_enable, 0},
579 	{"quadword-load-store", feat_enable, 0},
580 	{"vector-crypto", feat_enable, 0},
581 	{"mmu-hash", feat_enable_mmu_hash, 0},
582 	{"mmu-radix", feat_enable_mmu_radix, 0},
583 	{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
584 	{"virtual-page-class-key-protection", feat_enable, 0},
585 	{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
586 	{"transactional-memory-v3", feat_enable_tm, 0},
587 	{"tm-suspend-hypervisor-assist", feat_enable, CPU_FTR_P9_TM_HV_ASSIST},
588 	{"tm-suspend-xer-so-bug", feat_enable, CPU_FTR_P9_TM_XER_SO_BUG},
589 	{"idle-nap", feat_enable_idle_nap, 0},
590 	{"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0},
591 	{"idle-stop", feat_enable_idle_stop, 0},
592 	{"machine-check-power8", feat_enable_mce_power8, 0},
593 	{"performance-monitor-power8", feat_enable_pmu_power8, 0},
594 	{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
595 	{"event-based-branch", feat_enable_ebb, 0},
596 	{"target-address-register", feat_enable, 0},
597 	{"branch-history-rolling-buffer", feat_enable, 0},
598 	{"control-register", feat_enable, CPU_FTR_CTRL},
599 	{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
600 	{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
601 	{"processor-utilization-of-resources-register", feat_enable_purr, 0},
602 	{"no-execute", feat_enable, 0},
603 	{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
604 	{"cache-inhibited-large-page", feat_enable_large_ci, 0},
605 	{"coprocessor-icswx", feat_enable, 0},
606 	{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
607 	{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
608 	{"wait", feat_enable, 0},
609 	{"atomic-memory-operations", feat_enable, 0},
610 	{"branch-v3", feat_enable, 0},
611 	{"copy-paste", feat_enable, 0},
612 	{"decimal-floating-point-v3", feat_enable, 0},
613 	{"decimal-integer-v3", feat_enable, 0},
614 	{"fixed-point-v3", feat_enable, 0},
615 	{"floating-point-v3", feat_enable, 0},
616 	{"group-start-register", feat_enable, 0},
617 	{"pc-relative-addressing", feat_enable, 0},
618 	{"machine-check-power9", feat_enable_mce_power9, 0},
619 	{"performance-monitor-power9", feat_enable_pmu_power9, 0},
620 	{"event-based-branch-v3", feat_enable, 0},
621 	{"random-number-generator", feat_enable, 0},
622 	{"system-call-vectored", feat_disable, 0},
623 	{"trace-interrupt-v3", feat_enable, 0},
624 	{"vector-v3", feat_enable, 0},
625 	{"vector-binary128", feat_enable, 0},
626 	{"vector-binary16", feat_enable, 0},
627 	{"wait-v3", feat_enable, 0},
628 };
629 
630 static bool __initdata using_dt_cpu_ftrs;
631 static bool __initdata enable_unknown = true;
632 
633 static int __init dt_cpu_ftrs_parse(char *str)
634 {
635 	if (!str)
636 		return 0;
637 
638 	if (!strcmp(str, "off"))
639 		using_dt_cpu_ftrs = false;
640 	else if (!strcmp(str, "known"))
641 		enable_unknown = false;
642 	else
643 		return 1;
644 
645 	return 0;
646 }
647 early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
648 
649 static void __init cpufeatures_setup_start(u32 isa)
650 {
651 	pr_info("setup for ISA %d\n", isa);
652 
653 	if (isa >= 3000) {
654 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
655 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
656 	}
657 }
658 
659 static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
660 {
661 	const struct dt_cpu_feature_match *m;
662 	bool known = false;
663 	int i;
664 
665 	for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
666 		m = &dt_cpu_feature_match_table[i];
667 		if (!strcmp(f->name, m->name)) {
668 			known = true;
669 			if (m->enable(f))
670 				break;
671 
672 			pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
673 				f->name);
674 			return false;
675 		}
676 	}
677 
678 	if (!known && enable_unknown) {
679 		if (!feat_try_enable_unknown(f)) {
680 			pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
681 				f->name);
682 			return false;
683 		}
684 	}
685 
686 	if (m->cpu_ftr_bit_mask)
687 		cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
688 
689 	if (known)
690 		pr_debug("enabling: %s\n", f->name);
691 	else
692 		pr_debug("enabling: %s (unknown)\n", f->name);
693 
694 	return true;
695 }
696 
697 static __init void cpufeatures_cpu_quirks(void)
698 {
699 	int version = mfspr(SPRN_PVR);
700 
701 	/*
702 	 * Not all quirks can be derived from the cpufeatures device tree.
703 	 */
704 	if ((version & 0xffffefff) == 0x004e0200)
705 		; /* DD2.0 has no feature flag */
706 	else if ((version & 0xffffefff) == 0x004e0201)
707 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
708 	else if ((version & 0xffffefff) == 0x004e0202) {
709 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
710 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
711 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
712 	} else if ((version & 0xffff0000) == 0x004e0000)
713 		/* DD2.1 and up have DD2_1 */
714 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
715 
716 	if ((version & 0xffff0000) == 0x004e0000) {
717 		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
718 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_BUG;
719 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TIDR;
720 	}
721 
722 	/*
723 	 * PKEY was not in the initial base or feature node
724 	 * specification, but it should become optional in the next
725 	 * cpu feature version sequence.
726 	 */
727 	cur_cpu_spec->cpu_features |= CPU_FTR_PKEY;
728 }
729 
730 static void __init cpufeatures_setup_finished(void)
731 {
732 	cpufeatures_cpu_quirks();
733 
734 	if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
735 		pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
736 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
737 	}
738 
739 	/* Make sure powerpc_base_platform is non-NULL */
740 	powerpc_base_platform = cur_cpu_spec->platform;
741 
742 	system_registers.lpcr = mfspr(SPRN_LPCR);
743 	system_registers.hfscr = mfspr(SPRN_HFSCR);
744 	system_registers.fscr = mfspr(SPRN_FSCR);
745 
746 	pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
747 		cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
748 }
749 
750 static int __init disabled_on_cmdline(void)
751 {
752 	unsigned long root, chosen;
753 	const char *p;
754 
755 	root = of_get_flat_dt_root();
756 	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
757 	if (chosen == -FDT_ERR_NOTFOUND)
758 		return false;
759 
760 	p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
761 	if (!p)
762 		return false;
763 
764 	if (strstr(p, "dt_cpu_ftrs=off"))
765 		return true;
766 
767 	return false;
768 }
769 
770 static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
771 					int depth, void *data)
772 {
773 	if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
774 	    && of_get_flat_dt_prop(node, "isa", NULL))
775 		return 1;
776 
777 	return 0;
778 }
779 
780 bool __init dt_cpu_ftrs_in_use(void)
781 {
782 	return using_dt_cpu_ftrs;
783 }
784 
785 bool __init dt_cpu_ftrs_init(void *fdt)
786 {
787 	using_dt_cpu_ftrs = false;
788 
789 	/* Setup and verify the FDT, if it fails we just bail */
790 	if (!early_init_dt_verify(fdt))
791 		return false;
792 
793 	if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
794 		return false;
795 
796 	if (disabled_on_cmdline())
797 		return false;
798 
799 	cpufeatures_setup_cpu();
800 
801 	using_dt_cpu_ftrs = true;
802 	return true;
803 }
804 
805 static int nr_dt_cpu_features;
806 static struct dt_cpu_feature *dt_cpu_features;
807 
808 static int __init process_cpufeatures_node(unsigned long node,
809 					  const char *uname, int i)
810 {
811 	const __be32 *prop;
812 	struct dt_cpu_feature *f;
813 	int len;
814 
815 	f = &dt_cpu_features[i];
816 	memset(f, 0, sizeof(struct dt_cpu_feature));
817 
818 	f->node = node;
819 
820 	f->name = uname;
821 
822 	prop = of_get_flat_dt_prop(node, "isa", &len);
823 	if (!prop) {
824 		pr_warn("%s: missing isa property\n", uname);
825 		return 0;
826 	}
827 	f->isa = be32_to_cpup(prop);
828 
829 	prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
830 	if (!prop) {
831 		pr_warn("%s: missing usable-privilege property", uname);
832 		return 0;
833 	}
834 	f->usable_privilege = be32_to_cpup(prop);
835 
836 	prop = of_get_flat_dt_prop(node, "hv-support", &len);
837 	if (prop)
838 		f->hv_support = be32_to_cpup(prop);
839 	else
840 		f->hv_support = HV_SUPPORT_NONE;
841 
842 	prop = of_get_flat_dt_prop(node, "os-support", &len);
843 	if (prop)
844 		f->os_support = be32_to_cpup(prop);
845 	else
846 		f->os_support = OS_SUPPORT_NONE;
847 
848 	prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
849 	if (prop)
850 		f->hfscr_bit_nr = be32_to_cpup(prop);
851 	else
852 		f->hfscr_bit_nr = -1;
853 	prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
854 	if (prop)
855 		f->fscr_bit_nr = be32_to_cpup(prop);
856 	else
857 		f->fscr_bit_nr = -1;
858 	prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
859 	if (prop)
860 		f->hwcap_bit_nr = be32_to_cpup(prop);
861 	else
862 		f->hwcap_bit_nr = -1;
863 
864 	if (f->usable_privilege & USABLE_HV) {
865 		if (!(mfmsr() & MSR_HV)) {
866 			pr_warn("%s: HV feature passed to guest\n", uname);
867 			return 0;
868 		}
869 
870 		if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
871 			pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
872 			return 0;
873 		}
874 
875 		if (f->hv_support == HV_SUPPORT_HFSCR) {
876 			if (f->hfscr_bit_nr == -1) {
877 				pr_warn("%s: missing hfscr_bit_nr\n", uname);
878 				return 0;
879 			}
880 		}
881 	} else {
882 		if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
883 			pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
884 			return 0;
885 		}
886 	}
887 
888 	if (f->usable_privilege & USABLE_OS) {
889 		if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
890 			pr_warn("%s: unwanted fscr_bit_nr\n", uname);
891 			return 0;
892 		}
893 
894 		if (f->os_support == OS_SUPPORT_FSCR) {
895 			if (f->fscr_bit_nr == -1) {
896 				pr_warn("%s: missing fscr_bit_nr\n", uname);
897 				return 0;
898 			}
899 		}
900 	} else {
901 		if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
902 			pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
903 			return 0;
904 		}
905 	}
906 
907 	if (!(f->usable_privilege & USABLE_PR)) {
908 		if (f->hwcap_bit_nr != -1) {
909 			pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
910 			return 0;
911 		}
912 	}
913 
914 	/* Do all the independent features in the first pass */
915 	if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
916 		if (cpufeatures_process_feature(f))
917 			f->enabled = 1;
918 		else
919 			f->disabled = 1;
920 	}
921 
922 	return 0;
923 }
924 
925 static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
926 {
927 	const __be32 *prop;
928 	int len;
929 	int nr_deps;
930 	int i;
931 
932 	if (f->enabled || f->disabled)
933 		return;
934 
935 	prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
936 	if (!prop) {
937 		pr_warn("%s: missing dependencies property", f->name);
938 		return;
939 	}
940 
941 	nr_deps = len / sizeof(int);
942 
943 	for (i = 0; i < nr_deps; i++) {
944 		unsigned long phandle = be32_to_cpu(prop[i]);
945 		int j;
946 
947 		for (j = 0; j < nr_dt_cpu_features; j++) {
948 			struct dt_cpu_feature *d = &dt_cpu_features[j];
949 
950 			if (of_get_flat_dt_phandle(d->node) == phandle) {
951 				cpufeatures_deps_enable(d);
952 				if (d->disabled) {
953 					f->disabled = 1;
954 					return;
955 				}
956 			}
957 		}
958 	}
959 
960 	if (cpufeatures_process_feature(f))
961 		f->enabled = 1;
962 	else
963 		f->disabled = 1;
964 }
965 
966 static int __init scan_cpufeatures_subnodes(unsigned long node,
967 					  const char *uname,
968 					  void *data)
969 {
970 	int *count = data;
971 
972 	process_cpufeatures_node(node, uname, *count);
973 
974 	(*count)++;
975 
976 	return 0;
977 }
978 
979 static int __init count_cpufeatures_subnodes(unsigned long node,
980 					  const char *uname,
981 					  void *data)
982 {
983 	int *count = data;
984 
985 	(*count)++;
986 
987 	return 0;
988 }
989 
990 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
991 					    *uname, int depth, void *data)
992 {
993 	const __be32 *prop;
994 	int count, i;
995 	u32 isa;
996 
997 	/* We are scanning "ibm,powerpc-cpu-features" nodes only */
998 	if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
999 		return 0;
1000 
1001 	prop = of_get_flat_dt_prop(node, "isa", NULL);
1002 	if (!prop)
1003 		/* We checked before, "can't happen" */
1004 		return 0;
1005 
1006 	isa = be32_to_cpup(prop);
1007 
1008 	/* Count and allocate space for cpu features */
1009 	of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
1010 						&nr_dt_cpu_features);
1011 	dt_cpu_features = __va(memblock_phys_alloc(sizeof(struct dt_cpu_feature) * nr_dt_cpu_features, PAGE_SIZE));
1012 
1013 	cpufeatures_setup_start(isa);
1014 
1015 	/* Scan nodes into dt_cpu_features and enable those without deps  */
1016 	count = 0;
1017 	of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
1018 
1019 	/* Recursive enable remaining features with dependencies */
1020 	for (i = 0; i < nr_dt_cpu_features; i++) {
1021 		struct dt_cpu_feature *f = &dt_cpu_features[i];
1022 
1023 		cpufeatures_deps_enable(f);
1024 	}
1025 
1026 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
1027 	if (prop && strlen((char *)prop) != 0) {
1028 		strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
1029 		cur_cpu_spec->cpu_name = dt_cpu_name;
1030 	}
1031 
1032 	cpufeatures_setup_finished();
1033 
1034 	memblock_free(__pa(dt_cpu_features),
1035 			sizeof(struct dt_cpu_feature)*nr_dt_cpu_features);
1036 
1037 	return 0;
1038 }
1039 
1040 void __init dt_cpu_ftrs_scan(void)
1041 {
1042 	if (!using_dt_cpu_ftrs)
1043 		return;
1044 
1045 	of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
1046 }
1047