xref: /linux/arch/powerpc/kernel/dt_cpu_ftrs.c (revision e3b9f1e81de2083f359bacd2a94bf1c024f2ede0)
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 long __machine_check_early_realmode_p8(struct pt_regs *regs);
81 extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
82 
83 static int hv_mode;
84 
85 static struct {
86 	u64	lpcr;
87 	u64	hfscr;
88 	u64	fscr;
89 } system_registers;
90 
91 static void (*init_pmu_registers)(void);
92 
93 static void __restore_cpu_cpufeatures(void)
94 {
95 	/*
96 	 * LPCR is restored by the power on engine already. It can be changed
97 	 * after early init e.g., by radix enable, and we have no unified API
98 	 * for saving and restoring such SPRs.
99 	 *
100 	 * This ->restore hook should really be removed from idle and register
101 	 * restore moved directly into the idle restore code, because this code
102 	 * doesn't know how idle is implemented or what it needs restored here.
103 	 *
104 	 * The best we can do to accommodate secondary boot and idle restore
105 	 * for now is "or" LPCR with existing.
106 	 */
107 
108 	mtspr(SPRN_LPCR, system_registers.lpcr | mfspr(SPRN_LPCR));
109 	if (hv_mode) {
110 		mtspr(SPRN_LPID, 0);
111 		mtspr(SPRN_HFSCR, system_registers.hfscr);
112 	}
113 	mtspr(SPRN_FSCR, system_registers.fscr);
114 
115 	if (init_pmu_registers)
116 		init_pmu_registers();
117 }
118 
119 static char dt_cpu_name[64];
120 
121 static struct cpu_spec __initdata base_cpu_spec = {
122 	.cpu_name		= NULL,
123 	.cpu_features		= CPU_FTRS_BASE,
124 	.cpu_user_features	= COMMON_USER_BASE,
125 	.cpu_user_features2	= COMMON_USER2_BASE,
126 	.mmu_features		= 0,
127 	.icache_bsize		= 32, /* minimum block size, fixed by */
128 	.dcache_bsize		= 32, /* cache info init.             */
129 	.num_pmcs		= 0,
130 	.pmc_type		= PPC_PMC_DEFAULT,
131 	.oprofile_cpu_type	= NULL,
132 	.oprofile_type		= PPC_OPROFILE_INVALID,
133 	.cpu_setup		= NULL,
134 	.cpu_restore		= __restore_cpu_cpufeatures,
135 	.machine_check_early	= NULL,
136 	.platform		= NULL,
137 };
138 
139 static void __init cpufeatures_setup_cpu(void)
140 {
141 	set_cur_cpu_spec(&base_cpu_spec);
142 
143 	cur_cpu_spec->pvr_mask = -1;
144 	cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
145 
146 	/* Initialize the base environment -- clear FSCR/HFSCR.  */
147 	hv_mode = !!(mfmsr() & MSR_HV);
148 	if (hv_mode) {
149 		/* CPU_FTR_HVMODE is used early in PACA setup */
150 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
151 		mtspr(SPRN_HFSCR, 0);
152 	}
153 	mtspr(SPRN_FSCR, 0);
154 
155 	/*
156 	 * LPCR does not get cleared, to match behaviour with secondaries
157 	 * in __restore_cpu_cpufeatures. Once the idle code is fixed, this
158 	 * could clear LPCR too.
159 	 */
160 }
161 
162 static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
163 {
164 	if (f->hv_support == HV_SUPPORT_NONE) {
165 	} else if (f->hv_support & HV_SUPPORT_HFSCR) {
166 		u64 hfscr = mfspr(SPRN_HFSCR);
167 		hfscr |= 1UL << f->hfscr_bit_nr;
168 		mtspr(SPRN_HFSCR, hfscr);
169 	} else {
170 		/* Does not have a known recipe */
171 		return 0;
172 	}
173 
174 	if (f->os_support == OS_SUPPORT_NONE) {
175 	} else if (f->os_support & OS_SUPPORT_FSCR) {
176 		u64 fscr = mfspr(SPRN_FSCR);
177 		fscr |= 1UL << f->fscr_bit_nr;
178 		mtspr(SPRN_FSCR, fscr);
179 	} else {
180 		/* Does not have a known recipe */
181 		return 0;
182 	}
183 
184 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
185 		uint32_t word = f->hwcap_bit_nr / 32;
186 		uint32_t bit = f->hwcap_bit_nr % 32;
187 
188 		if (word == 0)
189 			cur_cpu_spec->cpu_user_features |= 1U << bit;
190 		else if (word == 1)
191 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
192 		else
193 			pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
194 	}
195 
196 	return 1;
197 }
198 
199 static int __init feat_enable(struct dt_cpu_feature *f)
200 {
201 	if (f->hv_support != HV_SUPPORT_NONE) {
202 		if (f->hfscr_bit_nr != -1) {
203 			u64 hfscr = mfspr(SPRN_HFSCR);
204 			hfscr |= 1UL << f->hfscr_bit_nr;
205 			mtspr(SPRN_HFSCR, hfscr);
206 		}
207 	}
208 
209 	if (f->os_support != OS_SUPPORT_NONE) {
210 		if (f->fscr_bit_nr != -1) {
211 			u64 fscr = mfspr(SPRN_FSCR);
212 			fscr |= 1UL << f->fscr_bit_nr;
213 			mtspr(SPRN_FSCR, fscr);
214 		}
215 	}
216 
217 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
218 		uint32_t word = f->hwcap_bit_nr / 32;
219 		uint32_t bit = f->hwcap_bit_nr % 32;
220 
221 		if (word == 0)
222 			cur_cpu_spec->cpu_user_features |= 1U << bit;
223 		else if (word == 1)
224 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
225 		else
226 			pr_err("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
227 	}
228 
229 	return 1;
230 }
231 
232 static int __init feat_disable(struct dt_cpu_feature *f)
233 {
234 	return 0;
235 }
236 
237 static int __init feat_enable_hv(struct dt_cpu_feature *f)
238 {
239 	u64 lpcr;
240 
241 	if (!hv_mode) {
242 		pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
243 		return 0;
244 	}
245 
246 	mtspr(SPRN_LPID, 0);
247 
248 	lpcr = mfspr(SPRN_LPCR);
249 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
250 	mtspr(SPRN_LPCR, lpcr);
251 
252 	cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
253 
254 	return 1;
255 }
256 
257 static int __init feat_enable_le(struct dt_cpu_feature *f)
258 {
259 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
260 	return 1;
261 }
262 
263 static int __init feat_enable_smt(struct dt_cpu_feature *f)
264 {
265 	cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
266 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
267 	return 1;
268 }
269 
270 static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
271 {
272 	u64 lpcr;
273 
274 	/* Set PECE wakeup modes for ISA 207 */
275 	lpcr = mfspr(SPRN_LPCR);
276 	lpcr |=  LPCR_PECE0;
277 	lpcr |=  LPCR_PECE1;
278 	lpcr |=  LPCR_PECE2;
279 	mtspr(SPRN_LPCR, lpcr);
280 
281 	return 1;
282 }
283 
284 static int __init feat_enable_align_dsisr(struct dt_cpu_feature *f)
285 {
286 	cur_cpu_spec->cpu_features &= ~CPU_FTR_NODSISRALIGN;
287 
288 	return 1;
289 }
290 
291 static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
292 {
293 	u64 lpcr;
294 
295 	/* Set PECE wakeup modes for ISAv3.0B */
296 	lpcr = mfspr(SPRN_LPCR);
297 	lpcr |=  LPCR_PECE0;
298 	lpcr |=  LPCR_PECE1;
299 	lpcr |=  LPCR_PECE2;
300 	mtspr(SPRN_LPCR, lpcr);
301 
302 	return 1;
303 }
304 
305 static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
306 {
307 	u64 lpcr;
308 
309 	lpcr = mfspr(SPRN_LPCR);
310 	lpcr &= ~LPCR_ISL;
311 
312 	/* VRMASD */
313 	lpcr |= LPCR_VPM0;
314 	lpcr &= ~LPCR_VPM1;
315 	lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
316 	mtspr(SPRN_LPCR, lpcr);
317 
318 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
319 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
320 
321 	return 1;
322 }
323 
324 static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
325 {
326 	u64 lpcr;
327 
328 	lpcr = mfspr(SPRN_LPCR);
329 	lpcr &= ~LPCR_ISL;
330 	mtspr(SPRN_LPCR, lpcr);
331 
332 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
333 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
334 
335 	return 1;
336 }
337 
338 
339 static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
340 {
341 #ifdef CONFIG_PPC_RADIX_MMU
342 	cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
343 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
344 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
345 
346 	return 1;
347 #endif
348 	return 0;
349 }
350 
351 static int __init feat_enable_dscr(struct dt_cpu_feature *f)
352 {
353 	u64 lpcr;
354 
355 	feat_enable(f);
356 
357 	lpcr = mfspr(SPRN_LPCR);
358 	lpcr &= ~LPCR_DPFD;
359 	lpcr |=  (4UL << LPCR_DPFD_SH);
360 	mtspr(SPRN_LPCR, lpcr);
361 
362 	return 1;
363 }
364 
365 static void hfscr_pmu_enable(void)
366 {
367 	u64 hfscr = mfspr(SPRN_HFSCR);
368 	hfscr |= PPC_BIT(60);
369 	mtspr(SPRN_HFSCR, hfscr);
370 }
371 
372 static void init_pmu_power8(void)
373 {
374 	if (hv_mode) {
375 		mtspr(SPRN_MMCRC, 0);
376 		mtspr(SPRN_MMCRH, 0);
377 	}
378 
379 	mtspr(SPRN_MMCRA, 0);
380 	mtspr(SPRN_MMCR0, 0);
381 	mtspr(SPRN_MMCR1, 0);
382 	mtspr(SPRN_MMCR2, 0);
383 	mtspr(SPRN_MMCRS, 0);
384 }
385 
386 static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
387 {
388 	cur_cpu_spec->platform = "power8";
389 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
390 
391 	return 1;
392 }
393 
394 static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
395 {
396 	hfscr_pmu_enable();
397 
398 	init_pmu_power8();
399 	init_pmu_registers = init_pmu_power8;
400 
401 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
402 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
403 	if (pvr_version_is(PVR_POWER8E))
404 		cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
405 
406 	cur_cpu_spec->num_pmcs		= 6;
407 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
408 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power8";
409 
410 	return 1;
411 }
412 
413 static void init_pmu_power9(void)
414 {
415 	if (hv_mode)
416 		mtspr(SPRN_MMCRC, 0);
417 
418 	mtspr(SPRN_MMCRA, 0);
419 	mtspr(SPRN_MMCR0, 0);
420 	mtspr(SPRN_MMCR1, 0);
421 	mtspr(SPRN_MMCR2, 0);
422 }
423 
424 static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
425 {
426 	cur_cpu_spec->platform = "power9";
427 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
428 
429 	return 1;
430 }
431 
432 static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
433 {
434 	hfscr_pmu_enable();
435 
436 	init_pmu_power9();
437 	init_pmu_registers = init_pmu_power9;
438 
439 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
440 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
441 
442 	cur_cpu_spec->num_pmcs		= 6;
443 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
444 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power9";
445 
446 	return 1;
447 }
448 
449 static int __init feat_enable_tm(struct dt_cpu_feature *f)
450 {
451 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
452 	feat_enable(f);
453 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
454 	return 1;
455 #endif
456 	return 0;
457 }
458 
459 static int __init feat_enable_fp(struct dt_cpu_feature *f)
460 {
461 	feat_enable(f);
462 	cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
463 
464 	return 1;
465 }
466 
467 static int __init feat_enable_vector(struct dt_cpu_feature *f)
468 {
469 #ifdef CONFIG_ALTIVEC
470 	feat_enable(f);
471 	cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
472 	cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
473 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
474 
475 	return 1;
476 #endif
477 	return 0;
478 }
479 
480 static int __init feat_enable_vsx(struct dt_cpu_feature *f)
481 {
482 #ifdef CONFIG_VSX
483 	feat_enable(f);
484 	cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
485 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
486 
487 	return 1;
488 #endif
489 	return 0;
490 }
491 
492 static int __init feat_enable_purr(struct dt_cpu_feature *f)
493 {
494 	cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
495 
496 	return 1;
497 }
498 
499 static int __init feat_enable_ebb(struct dt_cpu_feature *f)
500 {
501 	/*
502 	 * PPC_FEATURE2_EBB is enabled in PMU init code because it has
503 	 * historically been related to the PMU facility. This may have
504 	 * to be decoupled if EBB becomes more generic. For now, follow
505 	 * existing convention.
506 	 */
507 	f->hwcap_bit_nr = -1;
508 	feat_enable(f);
509 
510 	return 1;
511 }
512 
513 static int __init feat_enable_dbell(struct dt_cpu_feature *f)
514 {
515 	u64 lpcr;
516 
517 	/* P9 has an HFSCR for privileged state */
518 	feat_enable(f);
519 
520 	cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
521 
522 	lpcr = mfspr(SPRN_LPCR);
523 	lpcr |=  LPCR_PECEDH; /* hyp doorbell wakeup */
524 	mtspr(SPRN_LPCR, lpcr);
525 
526 	return 1;
527 }
528 
529 static int __init feat_enable_hvi(struct dt_cpu_feature *f)
530 {
531 	u64 lpcr;
532 
533 	/*
534 	 * POWER9 XIVE interrupts including in OPAL XICS compatibility
535 	 * are always delivered as hypervisor virtualization interrupts (HVI)
536 	 * rather than EE.
537 	 *
538 	 * However LPES0 is not set here, in the chance that an EE does get
539 	 * delivered to the host somehow, the EE handler would not expect it
540 	 * to be delivered in LPES0 mode (e.g., using SRR[01]). This could
541 	 * happen if there is a bug in interrupt controller code, or IC is
542 	 * misconfigured in systemsim.
543 	 */
544 
545 	lpcr = mfspr(SPRN_LPCR);
546 	lpcr |= LPCR_HVICE;	/* enable hvi interrupts */
547 	lpcr |= LPCR_HEIC;	/* disable ee interrupts when MSR_HV */
548 	lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
549 	mtspr(SPRN_LPCR, lpcr);
550 
551 	return 1;
552 }
553 
554 static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
555 {
556 	cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
557 
558 	return 1;
559 }
560 
561 struct dt_cpu_feature_match {
562 	const char *name;
563 	int (*enable)(struct dt_cpu_feature *f);
564 	u64 cpu_ftr_bit_mask;
565 };
566 
567 static struct dt_cpu_feature_match __initdata
568 		dt_cpu_feature_match_table[] = {
569 	{"hypervisor", feat_enable_hv, 0},
570 	{"big-endian", feat_enable, 0},
571 	{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
572 	{"smt", feat_enable_smt, 0},
573 	{"interrupt-facilities", feat_enable, 0},
574 	{"timer-facilities", feat_enable, 0},
575 	{"timer-facilities-v3", feat_enable, 0},
576 	{"debug-facilities", feat_enable, 0},
577 	{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
578 	{"branch-tracing", feat_enable, 0},
579 	{"floating-point", feat_enable_fp, 0},
580 	{"vector", feat_enable_vector, 0},
581 	{"vector-scalar", feat_enable_vsx, 0},
582 	{"vector-scalar-v3", feat_enable, 0},
583 	{"decimal-floating-point", feat_enable, 0},
584 	{"decimal-integer", feat_enable, 0},
585 	{"quadword-load-store", feat_enable, 0},
586 	{"vector-crypto", feat_enable, 0},
587 	{"mmu-hash", feat_enable_mmu_hash, 0},
588 	{"mmu-radix", feat_enable_mmu_radix, 0},
589 	{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
590 	{"virtual-page-class-key-protection", feat_enable, 0},
591 	{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
592 	{"transactional-memory-v3", feat_enable_tm, 0},
593 	{"idle-nap", feat_enable_idle_nap, 0},
594 	{"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0},
595 	{"idle-stop", feat_enable_idle_stop, 0},
596 	{"machine-check-power8", feat_enable_mce_power8, 0},
597 	{"performance-monitor-power8", feat_enable_pmu_power8, 0},
598 	{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
599 	{"event-based-branch", feat_enable_ebb, 0},
600 	{"target-address-register", feat_enable, 0},
601 	{"branch-history-rolling-buffer", feat_enable, 0},
602 	{"control-register", feat_enable, CPU_FTR_CTRL},
603 	{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
604 	{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
605 	{"processor-utilization-of-resources-register", feat_enable_purr, 0},
606 	{"no-execute", feat_enable, 0},
607 	{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
608 	{"cache-inhibited-large-page", feat_enable_large_ci, 0},
609 	{"coprocessor-icswx", feat_enable, 0},
610 	{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
611 	{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
612 	{"wait", feat_enable, 0},
613 	{"atomic-memory-operations", feat_enable, 0},
614 	{"branch-v3", feat_enable, 0},
615 	{"copy-paste", feat_enable, 0},
616 	{"decimal-floating-point-v3", feat_enable, 0},
617 	{"decimal-integer-v3", feat_enable, 0},
618 	{"fixed-point-v3", feat_enable, 0},
619 	{"floating-point-v3", feat_enable, 0},
620 	{"group-start-register", feat_enable, 0},
621 	{"pc-relative-addressing", feat_enable, 0},
622 	{"machine-check-power9", feat_enable_mce_power9, 0},
623 	{"performance-monitor-power9", feat_enable_pmu_power9, 0},
624 	{"event-based-branch-v3", feat_enable, 0},
625 	{"random-number-generator", feat_enable, 0},
626 	{"system-call-vectored", feat_disable, 0},
627 	{"trace-interrupt-v3", feat_enable, 0},
628 	{"vector-v3", feat_enable, 0},
629 	{"vector-binary128", feat_enable, 0},
630 	{"vector-binary16", feat_enable, 0},
631 	{"wait-v3", feat_enable, 0},
632 };
633 
634 static bool __initdata using_dt_cpu_ftrs;
635 static bool __initdata enable_unknown = true;
636 
637 static int __init dt_cpu_ftrs_parse(char *str)
638 {
639 	if (!str)
640 		return 0;
641 
642 	if (!strcmp(str, "off"))
643 		using_dt_cpu_ftrs = false;
644 	else if (!strcmp(str, "known"))
645 		enable_unknown = false;
646 	else
647 		return 1;
648 
649 	return 0;
650 }
651 early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
652 
653 static void __init cpufeatures_setup_start(u32 isa)
654 {
655 	pr_info("setup for ISA %d\n", isa);
656 
657 	if (isa >= 3000) {
658 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
659 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
660 	}
661 }
662 
663 static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
664 {
665 	const struct dt_cpu_feature_match *m;
666 	bool known = false;
667 	int i;
668 
669 	for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
670 		m = &dt_cpu_feature_match_table[i];
671 		if (!strcmp(f->name, m->name)) {
672 			known = true;
673 			if (m->enable(f))
674 				break;
675 
676 			pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
677 				f->name);
678 			return false;
679 		}
680 	}
681 
682 	if (!known && enable_unknown) {
683 		if (!feat_try_enable_unknown(f)) {
684 			pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
685 				f->name);
686 			return false;
687 		}
688 	}
689 
690 	if (m->cpu_ftr_bit_mask)
691 		cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
692 
693 	if (known)
694 		pr_debug("enabling: %s\n", f->name);
695 	else
696 		pr_debug("enabling: %s (unknown)\n", f->name);
697 
698 	return true;
699 }
700 
701 static __init void cpufeatures_cpu_quirks(void)
702 {
703 	int version = mfspr(SPRN_PVR);
704 
705 	/*
706 	 * Not all quirks can be derived from the cpufeatures device tree.
707 	 */
708 	if ((version & 0xffffff00) == 0x004e0100)
709 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD1;
710 	else if ((version & 0xffffefff) == 0x004e0201)
711 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
712 }
713 
714 static void __init cpufeatures_setup_finished(void)
715 {
716 	cpufeatures_cpu_quirks();
717 
718 	if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
719 		pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
720 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
721 	}
722 
723 	system_registers.lpcr = mfspr(SPRN_LPCR);
724 	system_registers.hfscr = mfspr(SPRN_HFSCR);
725 	system_registers.fscr = mfspr(SPRN_FSCR);
726 
727 	pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
728 		cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
729 }
730 
731 static int __init disabled_on_cmdline(void)
732 {
733 	unsigned long root, chosen;
734 	const char *p;
735 
736 	root = of_get_flat_dt_root();
737 	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
738 	if (chosen == -FDT_ERR_NOTFOUND)
739 		return false;
740 
741 	p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
742 	if (!p)
743 		return false;
744 
745 	if (strstr(p, "dt_cpu_ftrs=off"))
746 		return true;
747 
748 	return false;
749 }
750 
751 static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
752 					int depth, void *data)
753 {
754 	if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
755 	    && of_get_flat_dt_prop(node, "isa", NULL))
756 		return 1;
757 
758 	return 0;
759 }
760 
761 bool __init dt_cpu_ftrs_in_use(void)
762 {
763 	return using_dt_cpu_ftrs;
764 }
765 
766 bool __init dt_cpu_ftrs_init(void *fdt)
767 {
768 	using_dt_cpu_ftrs = false;
769 
770 	/* Setup and verify the FDT, if it fails we just bail */
771 	if (!early_init_dt_verify(fdt))
772 		return false;
773 
774 	if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
775 		return false;
776 
777 	if (disabled_on_cmdline())
778 		return false;
779 
780 	cpufeatures_setup_cpu();
781 
782 	using_dt_cpu_ftrs = true;
783 	return true;
784 }
785 
786 static int nr_dt_cpu_features;
787 static struct dt_cpu_feature *dt_cpu_features;
788 
789 static int __init process_cpufeatures_node(unsigned long node,
790 					  const char *uname, int i)
791 {
792 	const __be32 *prop;
793 	struct dt_cpu_feature *f;
794 	int len;
795 
796 	f = &dt_cpu_features[i];
797 	memset(f, 0, sizeof(struct dt_cpu_feature));
798 
799 	f->node = node;
800 
801 	f->name = uname;
802 
803 	prop = of_get_flat_dt_prop(node, "isa", &len);
804 	if (!prop) {
805 		pr_warn("%s: missing isa property\n", uname);
806 		return 0;
807 	}
808 	f->isa = be32_to_cpup(prop);
809 
810 	prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
811 	if (!prop) {
812 		pr_warn("%s: missing usable-privilege property", uname);
813 		return 0;
814 	}
815 	f->usable_privilege = be32_to_cpup(prop);
816 
817 	prop = of_get_flat_dt_prop(node, "hv-support", &len);
818 	if (prop)
819 		f->hv_support = be32_to_cpup(prop);
820 	else
821 		f->hv_support = HV_SUPPORT_NONE;
822 
823 	prop = of_get_flat_dt_prop(node, "os-support", &len);
824 	if (prop)
825 		f->os_support = be32_to_cpup(prop);
826 	else
827 		f->os_support = OS_SUPPORT_NONE;
828 
829 	prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
830 	if (prop)
831 		f->hfscr_bit_nr = be32_to_cpup(prop);
832 	else
833 		f->hfscr_bit_nr = -1;
834 	prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
835 	if (prop)
836 		f->fscr_bit_nr = be32_to_cpup(prop);
837 	else
838 		f->fscr_bit_nr = -1;
839 	prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
840 	if (prop)
841 		f->hwcap_bit_nr = be32_to_cpup(prop);
842 	else
843 		f->hwcap_bit_nr = -1;
844 
845 	if (f->usable_privilege & USABLE_HV) {
846 		if (!(mfmsr() & MSR_HV)) {
847 			pr_warn("%s: HV feature passed to guest\n", uname);
848 			return 0;
849 		}
850 
851 		if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
852 			pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
853 			return 0;
854 		}
855 
856 		if (f->hv_support == HV_SUPPORT_HFSCR) {
857 			if (f->hfscr_bit_nr == -1) {
858 				pr_warn("%s: missing hfscr_bit_nr\n", uname);
859 				return 0;
860 			}
861 		}
862 	} else {
863 		if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
864 			pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
865 			return 0;
866 		}
867 	}
868 
869 	if (f->usable_privilege & USABLE_OS) {
870 		if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
871 			pr_warn("%s: unwanted fscr_bit_nr\n", uname);
872 			return 0;
873 		}
874 
875 		if (f->os_support == OS_SUPPORT_FSCR) {
876 			if (f->fscr_bit_nr == -1) {
877 				pr_warn("%s: missing fscr_bit_nr\n", uname);
878 				return 0;
879 			}
880 		}
881 	} else {
882 		if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
883 			pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
884 			return 0;
885 		}
886 	}
887 
888 	if (!(f->usable_privilege & USABLE_PR)) {
889 		if (f->hwcap_bit_nr != -1) {
890 			pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
891 			return 0;
892 		}
893 	}
894 
895 	/* Do all the independent features in the first pass */
896 	if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
897 		if (cpufeatures_process_feature(f))
898 			f->enabled = 1;
899 		else
900 			f->disabled = 1;
901 	}
902 
903 	return 0;
904 }
905 
906 static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
907 {
908 	const __be32 *prop;
909 	int len;
910 	int nr_deps;
911 	int i;
912 
913 	if (f->enabled || f->disabled)
914 		return;
915 
916 	prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
917 	if (!prop) {
918 		pr_warn("%s: missing dependencies property", f->name);
919 		return;
920 	}
921 
922 	nr_deps = len / sizeof(int);
923 
924 	for (i = 0; i < nr_deps; i++) {
925 		unsigned long phandle = be32_to_cpu(prop[i]);
926 		int j;
927 
928 		for (j = 0; j < nr_dt_cpu_features; j++) {
929 			struct dt_cpu_feature *d = &dt_cpu_features[j];
930 
931 			if (of_get_flat_dt_phandle(d->node) == phandle) {
932 				cpufeatures_deps_enable(d);
933 				if (d->disabled) {
934 					f->disabled = 1;
935 					return;
936 				}
937 			}
938 		}
939 	}
940 
941 	if (cpufeatures_process_feature(f))
942 		f->enabled = 1;
943 	else
944 		f->disabled = 1;
945 }
946 
947 static int __init scan_cpufeatures_subnodes(unsigned long node,
948 					  const char *uname,
949 					  void *data)
950 {
951 	int *count = data;
952 
953 	process_cpufeatures_node(node, uname, *count);
954 
955 	(*count)++;
956 
957 	return 0;
958 }
959 
960 static int __init count_cpufeatures_subnodes(unsigned long node,
961 					  const char *uname,
962 					  void *data)
963 {
964 	int *count = data;
965 
966 	(*count)++;
967 
968 	return 0;
969 }
970 
971 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
972 					    *uname, int depth, void *data)
973 {
974 	const __be32 *prop;
975 	int count, i;
976 	u32 isa;
977 
978 	/* We are scanning "ibm,powerpc-cpu-features" nodes only */
979 	if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
980 		return 0;
981 
982 	prop = of_get_flat_dt_prop(node, "isa", NULL);
983 	if (!prop)
984 		/* We checked before, "can't happen" */
985 		return 0;
986 
987 	isa = be32_to_cpup(prop);
988 
989 	/* Count and allocate space for cpu features */
990 	of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
991 						&nr_dt_cpu_features);
992 	dt_cpu_features = __va(
993 		memblock_alloc(sizeof(struct dt_cpu_feature)*
994 				nr_dt_cpu_features, PAGE_SIZE));
995 
996 	cpufeatures_setup_start(isa);
997 
998 	/* Scan nodes into dt_cpu_features and enable those without deps  */
999 	count = 0;
1000 	of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
1001 
1002 	/* Recursive enable remaining features with dependencies */
1003 	for (i = 0; i < nr_dt_cpu_features; i++) {
1004 		struct dt_cpu_feature *f = &dt_cpu_features[i];
1005 
1006 		cpufeatures_deps_enable(f);
1007 	}
1008 
1009 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
1010 	if (prop && strlen((char *)prop) != 0) {
1011 		strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
1012 		cur_cpu_spec->cpu_name = dt_cpu_name;
1013 	}
1014 
1015 	cpufeatures_setup_finished();
1016 
1017 	memblock_free(__pa(dt_cpu_features),
1018 			sizeof(struct dt_cpu_feature)*nr_dt_cpu_features);
1019 
1020 	return 0;
1021 }
1022 
1023 void __init dt_cpu_ftrs_scan(void)
1024 {
1025 	if (!using_dt_cpu_ftrs)
1026 		return;
1027 
1028 	of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
1029 }
1030