xref: /openbmc/linux/arch/powerpc/kernel/dt_cpu_ftrs.c (revision 2eb0f624b709e78ec8e2f4c3412947703db99301)
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_LWSYNC | \
58 	    CPU_FTR_FPU_UNAVAILABLE |\
59 	    CPU_FTR_NODSISRALIGN |\
60 	    CPU_FTR_NOEXECUTE |\
61 	    CPU_FTR_COHERENT_ICACHE | \
62 	    CPU_FTR_STCX_CHECKS_ADDRESS |\
63 	    CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
64 	    CPU_FTR_DAWR | \
65 	    CPU_FTR_ARCH_206 |\
66 	    CPU_FTR_ARCH_207S)
67 
68 #define MMU_FTRS_HASH_BASE (MMU_FTRS_POWER8)
69 
70 #define COMMON_USER_BASE	(PPC_FEATURE_32 | PPC_FEATURE_64 | \
71 				 PPC_FEATURE_ARCH_2_06 |\
72 				 PPC_FEATURE_ICACHE_SNOOP)
73 #define COMMON_USER2_BASE	(PPC_FEATURE2_ARCH_2_07 | \
74 				 PPC_FEATURE2_ISEL)
75 /*
76  * Set up the base CPU
77  */
78 
79 extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
80 extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
81 
82 static int hv_mode;
83 
84 static struct {
85 	u64	lpcr;
86 	u64	lpcr_clear;
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 	u64 lpcr;
96 
97 	/*
98 	 * LPCR is restored by the power on engine already. It can be changed
99 	 * after early init e.g., by radix enable, and we have no unified API
100 	 * for saving and restoring such SPRs.
101 	 *
102 	 * This ->restore hook should really be removed from idle and register
103 	 * restore moved directly into the idle restore code, because this code
104 	 * doesn't know how idle is implemented or what it needs restored here.
105 	 *
106 	 * The best we can do to accommodate secondary boot and idle restore
107 	 * for now is "or" LPCR with existing.
108 	 */
109 	lpcr = mfspr(SPRN_LPCR);
110 	lpcr |= system_registers.lpcr;
111 	lpcr &= ~system_registers.lpcr_clear;
112 	mtspr(SPRN_LPCR, lpcr);
113 	if (hv_mode) {
114 		mtspr(SPRN_LPID, 0);
115 		mtspr(SPRN_HFSCR, system_registers.hfscr);
116 	}
117 	mtspr(SPRN_FSCR, system_registers.fscr);
118 
119 	if (init_pmu_registers)
120 		init_pmu_registers();
121 }
122 
123 static char dt_cpu_name[64];
124 
125 static struct cpu_spec __initdata base_cpu_spec = {
126 	.cpu_name		= NULL,
127 	.cpu_features		= CPU_FTRS_BASE,
128 	.cpu_user_features	= COMMON_USER_BASE,
129 	.cpu_user_features2	= COMMON_USER2_BASE,
130 	.mmu_features		= 0,
131 	.icache_bsize		= 32, /* minimum block size, fixed by */
132 	.dcache_bsize		= 32, /* cache info init.             */
133 	.num_pmcs		= 0,
134 	.pmc_type		= PPC_PMC_DEFAULT,
135 	.oprofile_cpu_type	= NULL,
136 	.oprofile_type		= PPC_OPROFILE_INVALID,
137 	.cpu_setup		= NULL,
138 	.cpu_restore		= __restore_cpu_cpufeatures,
139 	.machine_check_early	= NULL,
140 	.platform		= NULL,
141 };
142 
143 static void __init cpufeatures_setup_cpu(void)
144 {
145 	set_cur_cpu_spec(&base_cpu_spec);
146 
147 	cur_cpu_spec->pvr_mask = -1;
148 	cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
149 
150 	/* Initialize the base environment -- clear FSCR/HFSCR.  */
151 	hv_mode = !!(mfmsr() & MSR_HV);
152 	if (hv_mode) {
153 		/* CPU_FTR_HVMODE is used early in PACA setup */
154 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
155 		mtspr(SPRN_HFSCR, 0);
156 	}
157 	mtspr(SPRN_FSCR, 0);
158 
159 	/*
160 	 * LPCR does not get cleared, to match behaviour with secondaries
161 	 * in __restore_cpu_cpufeatures. Once the idle code is fixed, this
162 	 * could clear LPCR too.
163 	 */
164 }
165 
166 static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
167 {
168 	if (f->hv_support == HV_SUPPORT_NONE) {
169 	} else if (f->hv_support & HV_SUPPORT_HFSCR) {
170 		u64 hfscr = mfspr(SPRN_HFSCR);
171 		hfscr |= 1UL << f->hfscr_bit_nr;
172 		mtspr(SPRN_HFSCR, hfscr);
173 	} else {
174 		/* Does not have a known recipe */
175 		return 0;
176 	}
177 
178 	if (f->os_support == OS_SUPPORT_NONE) {
179 	} else if (f->os_support & OS_SUPPORT_FSCR) {
180 		u64 fscr = mfspr(SPRN_FSCR);
181 		fscr |= 1UL << f->fscr_bit_nr;
182 		mtspr(SPRN_FSCR, fscr);
183 	} else {
184 		/* Does not have a known recipe */
185 		return 0;
186 	}
187 
188 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
189 		uint32_t word = f->hwcap_bit_nr / 32;
190 		uint32_t bit = f->hwcap_bit_nr % 32;
191 
192 		if (word == 0)
193 			cur_cpu_spec->cpu_user_features |= 1U << bit;
194 		else if (word == 1)
195 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
196 		else
197 			pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
198 	}
199 
200 	return 1;
201 }
202 
203 static int __init feat_enable(struct dt_cpu_feature *f)
204 {
205 	if (f->hv_support != HV_SUPPORT_NONE) {
206 		if (f->hfscr_bit_nr != -1) {
207 			u64 hfscr = mfspr(SPRN_HFSCR);
208 			hfscr |= 1UL << f->hfscr_bit_nr;
209 			mtspr(SPRN_HFSCR, hfscr);
210 		}
211 	}
212 
213 	if (f->os_support != OS_SUPPORT_NONE) {
214 		if (f->fscr_bit_nr != -1) {
215 			u64 fscr = mfspr(SPRN_FSCR);
216 			fscr |= 1UL << f->fscr_bit_nr;
217 			mtspr(SPRN_FSCR, fscr);
218 		}
219 	}
220 
221 	if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
222 		uint32_t word = f->hwcap_bit_nr / 32;
223 		uint32_t bit = f->hwcap_bit_nr % 32;
224 
225 		if (word == 0)
226 			cur_cpu_spec->cpu_user_features |= 1U << bit;
227 		else if (word == 1)
228 			cur_cpu_spec->cpu_user_features2 |= 1U << bit;
229 		else
230 			pr_err("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
231 	}
232 
233 	return 1;
234 }
235 
236 static int __init feat_disable(struct dt_cpu_feature *f)
237 {
238 	return 0;
239 }
240 
241 static int __init feat_enable_hv(struct dt_cpu_feature *f)
242 {
243 	u64 lpcr;
244 
245 	if (!hv_mode) {
246 		pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
247 		return 0;
248 	}
249 
250 	mtspr(SPRN_LPID, 0);
251 
252 	lpcr = mfspr(SPRN_LPCR);
253 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
254 	mtspr(SPRN_LPCR, lpcr);
255 
256 	cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
257 
258 	return 1;
259 }
260 
261 static int __init feat_enable_le(struct dt_cpu_feature *f)
262 {
263 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
264 	return 1;
265 }
266 
267 static int __init feat_enable_smt(struct dt_cpu_feature *f)
268 {
269 	cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
270 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
271 	return 1;
272 }
273 
274 static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
275 {
276 	u64 lpcr;
277 
278 	/* Set PECE wakeup modes for ISA 207 */
279 	lpcr = mfspr(SPRN_LPCR);
280 	lpcr |=  LPCR_PECE0;
281 	lpcr |=  LPCR_PECE1;
282 	lpcr |=  LPCR_PECE2;
283 	mtspr(SPRN_LPCR, lpcr);
284 
285 	return 1;
286 }
287 
288 static int __init feat_enable_align_dsisr(struct dt_cpu_feature *f)
289 {
290 	cur_cpu_spec->cpu_features &= ~CPU_FTR_NODSISRALIGN;
291 
292 	return 1;
293 }
294 
295 static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
296 {
297 	u64 lpcr;
298 
299 	/* Set PECE wakeup modes for ISAv3.0B */
300 	lpcr = mfspr(SPRN_LPCR);
301 	lpcr |=  LPCR_PECE0;
302 	lpcr |=  LPCR_PECE1;
303 	lpcr |=  LPCR_PECE2;
304 	mtspr(SPRN_LPCR, lpcr);
305 
306 	return 1;
307 }
308 
309 static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
310 {
311 	u64 lpcr;
312 
313 	lpcr = mfspr(SPRN_LPCR);
314 	lpcr &= ~LPCR_ISL;
315 
316 	/* VRMASD */
317 	lpcr |= LPCR_VPM0;
318 	lpcr &= ~LPCR_VPM1;
319 	lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
320 	mtspr(SPRN_LPCR, lpcr);
321 
322 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
323 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
324 
325 	return 1;
326 }
327 
328 static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
329 {
330 	u64 lpcr;
331 
332 	system_registers.lpcr_clear |= (LPCR_ISL | LPCR_UPRT | LPCR_HR);
333 	lpcr = mfspr(SPRN_LPCR);
334 	lpcr &= ~(LPCR_ISL | LPCR_UPRT | LPCR_HR);
335 	mtspr(SPRN_LPCR, lpcr);
336 
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 }
342 
343 
344 static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
345 {
346 #ifdef CONFIG_PPC_RADIX_MMU
347 	cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
348 	cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
349 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
350 
351 	return 1;
352 #endif
353 	return 0;
354 }
355 
356 static int __init feat_enable_dscr(struct dt_cpu_feature *f)
357 {
358 	u64 lpcr;
359 
360 	feat_enable(f);
361 
362 	lpcr = mfspr(SPRN_LPCR);
363 	lpcr &= ~LPCR_DPFD;
364 	lpcr |=  (4UL << LPCR_DPFD_SH);
365 	mtspr(SPRN_LPCR, lpcr);
366 
367 	return 1;
368 }
369 
370 static void hfscr_pmu_enable(void)
371 {
372 	u64 hfscr = mfspr(SPRN_HFSCR);
373 	hfscr |= PPC_BIT(60);
374 	mtspr(SPRN_HFSCR, hfscr);
375 }
376 
377 static void init_pmu_power8(void)
378 {
379 	if (hv_mode) {
380 		mtspr(SPRN_MMCRC, 0);
381 		mtspr(SPRN_MMCRH, 0);
382 	}
383 
384 	mtspr(SPRN_MMCRA, 0);
385 	mtspr(SPRN_MMCR0, 0);
386 	mtspr(SPRN_MMCR1, 0);
387 	mtspr(SPRN_MMCR2, 0);
388 	mtspr(SPRN_MMCRS, 0);
389 }
390 
391 static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
392 {
393 	cur_cpu_spec->platform = "power8";
394 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
395 
396 	return 1;
397 }
398 
399 static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
400 {
401 	hfscr_pmu_enable();
402 
403 	init_pmu_power8();
404 	init_pmu_registers = init_pmu_power8;
405 
406 	cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
407 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
408 	if (pvr_version_is(PVR_POWER8E))
409 		cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
410 
411 	cur_cpu_spec->num_pmcs		= 6;
412 	cur_cpu_spec->pmc_type		= PPC_PMC_IBM;
413 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power8";
414 
415 	return 1;
416 }
417 
418 static void init_pmu_power9(void)
419 {
420 	if (hv_mode)
421 		mtspr(SPRN_MMCRC, 0);
422 
423 	mtspr(SPRN_MMCRA, 0);
424 	mtspr(SPRN_MMCR0, 0);
425 	mtspr(SPRN_MMCR1, 0);
426 	mtspr(SPRN_MMCR2, 0);
427 }
428 
429 static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
430 {
431 	cur_cpu_spec->platform = "power9";
432 	cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
433 
434 	return 1;
435 }
436 
437 static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
438 {
439 	hfscr_pmu_enable();
440 
441 	init_pmu_power9();
442 	init_pmu_registers = init_pmu_power9;
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 	cur_cpu_spec->oprofile_cpu_type	= "ppc64/power9";
450 
451 	return 1;
452 }
453 
454 static int __init feat_enable_tm(struct dt_cpu_feature *f)
455 {
456 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
457 	feat_enable(f);
458 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
459 	return 1;
460 #endif
461 	return 0;
462 }
463 
464 static int __init feat_enable_fp(struct dt_cpu_feature *f)
465 {
466 	feat_enable(f);
467 	cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
468 
469 	return 1;
470 }
471 
472 static int __init feat_enable_vector(struct dt_cpu_feature *f)
473 {
474 #ifdef CONFIG_ALTIVEC
475 	feat_enable(f);
476 	cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
477 	cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
478 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
479 
480 	return 1;
481 #endif
482 	return 0;
483 }
484 
485 static int __init feat_enable_vsx(struct dt_cpu_feature *f)
486 {
487 #ifdef CONFIG_VSX
488 	feat_enable(f);
489 	cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
490 	cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
491 
492 	return 1;
493 #endif
494 	return 0;
495 }
496 
497 static int __init feat_enable_purr(struct dt_cpu_feature *f)
498 {
499 	cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
500 
501 	return 1;
502 }
503 
504 static int __init feat_enable_ebb(struct dt_cpu_feature *f)
505 {
506 	/*
507 	 * PPC_FEATURE2_EBB is enabled in PMU init code because it has
508 	 * historically been related to the PMU facility. This may have
509 	 * to be decoupled if EBB becomes more generic. For now, follow
510 	 * existing convention.
511 	 */
512 	f->hwcap_bit_nr = -1;
513 	feat_enable(f);
514 
515 	return 1;
516 }
517 
518 static int __init feat_enable_dbell(struct dt_cpu_feature *f)
519 {
520 	u64 lpcr;
521 
522 	/* P9 has an HFSCR for privileged state */
523 	feat_enable(f);
524 
525 	cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
526 
527 	lpcr = mfspr(SPRN_LPCR);
528 	lpcr |=  LPCR_PECEDH; /* hyp doorbell wakeup */
529 	mtspr(SPRN_LPCR, lpcr);
530 
531 	return 1;
532 }
533 
534 static int __init feat_enable_hvi(struct dt_cpu_feature *f)
535 {
536 	u64 lpcr;
537 
538 	/*
539 	 * POWER9 XIVE interrupts including in OPAL XICS compatibility
540 	 * are always delivered as hypervisor virtualization interrupts (HVI)
541 	 * rather than EE.
542 	 *
543 	 * However LPES0 is not set here, in the chance that an EE does get
544 	 * delivered to the host somehow, the EE handler would not expect it
545 	 * to be delivered in LPES0 mode (e.g., using SRR[01]). This could
546 	 * happen if there is a bug in interrupt controller code, or IC is
547 	 * misconfigured in systemsim.
548 	 */
549 
550 	lpcr = mfspr(SPRN_LPCR);
551 	lpcr |= LPCR_HVICE;	/* enable hvi interrupts */
552 	lpcr |= LPCR_HEIC;	/* disable ee interrupts when MSR_HV */
553 	lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
554 	mtspr(SPRN_LPCR, lpcr);
555 
556 	return 1;
557 }
558 
559 static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
560 {
561 	cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
562 
563 	return 1;
564 }
565 
566 struct dt_cpu_feature_match {
567 	const char *name;
568 	int (*enable)(struct dt_cpu_feature *f);
569 	u64 cpu_ftr_bit_mask;
570 };
571 
572 static struct dt_cpu_feature_match __initdata
573 		dt_cpu_feature_match_table[] = {
574 	{"hypervisor", feat_enable_hv, 0},
575 	{"big-endian", feat_enable, 0},
576 	{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
577 	{"smt", feat_enable_smt, 0},
578 	{"interrupt-facilities", feat_enable, 0},
579 	{"timer-facilities", feat_enable, 0},
580 	{"timer-facilities-v3", feat_enable, 0},
581 	{"debug-facilities", feat_enable, 0},
582 	{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
583 	{"branch-tracing", feat_enable, 0},
584 	{"floating-point", feat_enable_fp, 0},
585 	{"vector", feat_enable_vector, 0},
586 	{"vector-scalar", feat_enable_vsx, 0},
587 	{"vector-scalar-v3", feat_enable, 0},
588 	{"decimal-floating-point", feat_enable, 0},
589 	{"decimal-integer", feat_enable, 0},
590 	{"quadword-load-store", feat_enable, 0},
591 	{"vector-crypto", feat_enable, 0},
592 	{"mmu-hash", feat_enable_mmu_hash, 0},
593 	{"mmu-radix", feat_enable_mmu_radix, 0},
594 	{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
595 	{"virtual-page-class-key-protection", feat_enable, 0},
596 	{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
597 	{"transactional-memory-v3", feat_enable_tm, 0},
598 	{"tm-suspend-hypervisor-assist", feat_enable, CPU_FTR_P9_TM_HV_ASSIST},
599 	{"tm-suspend-xer-so-bug", feat_enable, CPU_FTR_P9_TM_XER_SO_BUG},
600 	{"idle-nap", feat_enable_idle_nap, 0},
601 	{"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0},
602 	{"idle-stop", feat_enable_idle_stop, 0},
603 	{"machine-check-power8", feat_enable_mce_power8, 0},
604 	{"performance-monitor-power8", feat_enable_pmu_power8, 0},
605 	{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
606 	{"event-based-branch", feat_enable_ebb, 0},
607 	{"target-address-register", feat_enable, 0},
608 	{"branch-history-rolling-buffer", feat_enable, 0},
609 	{"control-register", feat_enable, CPU_FTR_CTRL},
610 	{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
611 	{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
612 	{"processor-utilization-of-resources-register", feat_enable_purr, 0},
613 	{"no-execute", feat_enable, 0},
614 	{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
615 	{"cache-inhibited-large-page", feat_enable_large_ci, 0},
616 	{"coprocessor-icswx", feat_enable, 0},
617 	{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
618 	{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
619 	{"wait", feat_enable, 0},
620 	{"atomic-memory-operations", feat_enable, 0},
621 	{"branch-v3", feat_enable, 0},
622 	{"copy-paste", feat_enable, 0},
623 	{"decimal-floating-point-v3", feat_enable, 0},
624 	{"decimal-integer-v3", feat_enable, 0},
625 	{"fixed-point-v3", feat_enable, 0},
626 	{"floating-point-v3", feat_enable, 0},
627 	{"group-start-register", feat_enable, 0},
628 	{"pc-relative-addressing", feat_enable, 0},
629 	{"machine-check-power9", feat_enable_mce_power9, 0},
630 	{"performance-monitor-power9", feat_enable_pmu_power9, 0},
631 	{"event-based-branch-v3", feat_enable, 0},
632 	{"random-number-generator", feat_enable, 0},
633 	{"system-call-vectored", feat_disable, 0},
634 	{"trace-interrupt-v3", feat_enable, 0},
635 	{"vector-v3", feat_enable, 0},
636 	{"vector-binary128", feat_enable, 0},
637 	{"vector-binary16", feat_enable, 0},
638 	{"wait-v3", feat_enable, 0},
639 };
640 
641 static bool __initdata using_dt_cpu_ftrs;
642 static bool __initdata enable_unknown = true;
643 
644 static int __init dt_cpu_ftrs_parse(char *str)
645 {
646 	if (!str)
647 		return 0;
648 
649 	if (!strcmp(str, "off"))
650 		using_dt_cpu_ftrs = false;
651 	else if (!strcmp(str, "known"))
652 		enable_unknown = false;
653 	else
654 		return 1;
655 
656 	return 0;
657 }
658 early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
659 
660 static void __init cpufeatures_setup_start(u32 isa)
661 {
662 	pr_info("setup for ISA %d\n", isa);
663 
664 	if (isa >= 3000) {
665 		cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
666 		cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
667 	}
668 }
669 
670 static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
671 {
672 	const struct dt_cpu_feature_match *m;
673 	bool known = false;
674 	int i;
675 
676 	for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
677 		m = &dt_cpu_feature_match_table[i];
678 		if (!strcmp(f->name, m->name)) {
679 			known = true;
680 			if (m->enable(f))
681 				break;
682 
683 			pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
684 				f->name);
685 			return false;
686 		}
687 	}
688 
689 	if (!known && enable_unknown) {
690 		if (!feat_try_enable_unknown(f)) {
691 			pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
692 				f->name);
693 			return false;
694 		}
695 	}
696 
697 	if (m->cpu_ftr_bit_mask)
698 		cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
699 
700 	if (known)
701 		pr_debug("enabling: %s\n", f->name);
702 	else
703 		pr_debug("enabling: %s (unknown)\n", f->name);
704 
705 	return true;
706 }
707 
708 static __init void cpufeatures_cpu_quirks(void)
709 {
710 	int version = mfspr(SPRN_PVR);
711 
712 	/*
713 	 * Not all quirks can be derived from the cpufeatures device tree.
714 	 */
715 	if ((version & 0xffffff00) == 0x004e0100)
716 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD1;
717 	else if ((version & 0xffffefff) == 0x004e0200)
718 		; /* DD2.0 has no feature flag */
719 	else if ((version & 0xffffefff) == 0x004e0201)
720 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
721 	else if ((version & 0xffffefff) == 0x004e0202) {
722 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
723 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
724 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
725 	} else /* DD2.1 and up have DD2_1 */
726 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
727 
728 	if ((version & 0xffff0000) == 0x004e0000) {
729 		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
730 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_BUG;
731 	}
732 
733 	/*
734 	 * PKEY was not in the initial base or feature node
735 	 * specification, but it should become optional in the next
736 	 * cpu feature version sequence.
737 	 */
738 	cur_cpu_spec->cpu_features |= CPU_FTR_PKEY;
739 }
740 
741 static void __init cpufeatures_setup_finished(void)
742 {
743 	cpufeatures_cpu_quirks();
744 
745 	if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
746 		pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
747 		cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
748 	}
749 
750 	/* Make sure powerpc_base_platform is non-NULL */
751 	powerpc_base_platform = cur_cpu_spec->platform;
752 
753 	system_registers.lpcr = mfspr(SPRN_LPCR);
754 	system_registers.hfscr = mfspr(SPRN_HFSCR);
755 	system_registers.fscr = mfspr(SPRN_FSCR);
756 
757 	pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
758 		cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
759 }
760 
761 static int __init disabled_on_cmdline(void)
762 {
763 	unsigned long root, chosen;
764 	const char *p;
765 
766 	root = of_get_flat_dt_root();
767 	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
768 	if (chosen == -FDT_ERR_NOTFOUND)
769 		return false;
770 
771 	p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
772 	if (!p)
773 		return false;
774 
775 	if (strstr(p, "dt_cpu_ftrs=off"))
776 		return true;
777 
778 	return false;
779 }
780 
781 static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
782 					int depth, void *data)
783 {
784 	if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
785 	    && of_get_flat_dt_prop(node, "isa", NULL))
786 		return 1;
787 
788 	return 0;
789 }
790 
791 bool __init dt_cpu_ftrs_in_use(void)
792 {
793 	return using_dt_cpu_ftrs;
794 }
795 
796 bool __init dt_cpu_ftrs_init(void *fdt)
797 {
798 	using_dt_cpu_ftrs = false;
799 
800 	/* Setup and verify the FDT, if it fails we just bail */
801 	if (!early_init_dt_verify(fdt))
802 		return false;
803 
804 	if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
805 		return false;
806 
807 	if (disabled_on_cmdline())
808 		return false;
809 
810 	cpufeatures_setup_cpu();
811 
812 	using_dt_cpu_ftrs = true;
813 	return true;
814 }
815 
816 static int nr_dt_cpu_features;
817 static struct dt_cpu_feature *dt_cpu_features;
818 
819 static int __init process_cpufeatures_node(unsigned long node,
820 					  const char *uname, int i)
821 {
822 	const __be32 *prop;
823 	struct dt_cpu_feature *f;
824 	int len;
825 
826 	f = &dt_cpu_features[i];
827 	memset(f, 0, sizeof(struct dt_cpu_feature));
828 
829 	f->node = node;
830 
831 	f->name = uname;
832 
833 	prop = of_get_flat_dt_prop(node, "isa", &len);
834 	if (!prop) {
835 		pr_warn("%s: missing isa property\n", uname);
836 		return 0;
837 	}
838 	f->isa = be32_to_cpup(prop);
839 
840 	prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
841 	if (!prop) {
842 		pr_warn("%s: missing usable-privilege property", uname);
843 		return 0;
844 	}
845 	f->usable_privilege = be32_to_cpup(prop);
846 
847 	prop = of_get_flat_dt_prop(node, "hv-support", &len);
848 	if (prop)
849 		f->hv_support = be32_to_cpup(prop);
850 	else
851 		f->hv_support = HV_SUPPORT_NONE;
852 
853 	prop = of_get_flat_dt_prop(node, "os-support", &len);
854 	if (prop)
855 		f->os_support = be32_to_cpup(prop);
856 	else
857 		f->os_support = OS_SUPPORT_NONE;
858 
859 	prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
860 	if (prop)
861 		f->hfscr_bit_nr = be32_to_cpup(prop);
862 	else
863 		f->hfscr_bit_nr = -1;
864 	prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
865 	if (prop)
866 		f->fscr_bit_nr = be32_to_cpup(prop);
867 	else
868 		f->fscr_bit_nr = -1;
869 	prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
870 	if (prop)
871 		f->hwcap_bit_nr = be32_to_cpup(prop);
872 	else
873 		f->hwcap_bit_nr = -1;
874 
875 	if (f->usable_privilege & USABLE_HV) {
876 		if (!(mfmsr() & MSR_HV)) {
877 			pr_warn("%s: HV feature passed to guest\n", uname);
878 			return 0;
879 		}
880 
881 		if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
882 			pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
883 			return 0;
884 		}
885 
886 		if (f->hv_support == HV_SUPPORT_HFSCR) {
887 			if (f->hfscr_bit_nr == -1) {
888 				pr_warn("%s: missing hfscr_bit_nr\n", uname);
889 				return 0;
890 			}
891 		}
892 	} else {
893 		if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
894 			pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
895 			return 0;
896 		}
897 	}
898 
899 	if (f->usable_privilege & USABLE_OS) {
900 		if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
901 			pr_warn("%s: unwanted fscr_bit_nr\n", uname);
902 			return 0;
903 		}
904 
905 		if (f->os_support == OS_SUPPORT_FSCR) {
906 			if (f->fscr_bit_nr == -1) {
907 				pr_warn("%s: missing fscr_bit_nr\n", uname);
908 				return 0;
909 			}
910 		}
911 	} else {
912 		if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
913 			pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
914 			return 0;
915 		}
916 	}
917 
918 	if (!(f->usable_privilege & USABLE_PR)) {
919 		if (f->hwcap_bit_nr != -1) {
920 			pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
921 			return 0;
922 		}
923 	}
924 
925 	/* Do all the independent features in the first pass */
926 	if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
927 		if (cpufeatures_process_feature(f))
928 			f->enabled = 1;
929 		else
930 			f->disabled = 1;
931 	}
932 
933 	return 0;
934 }
935 
936 static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
937 {
938 	const __be32 *prop;
939 	int len;
940 	int nr_deps;
941 	int i;
942 
943 	if (f->enabled || f->disabled)
944 		return;
945 
946 	prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
947 	if (!prop) {
948 		pr_warn("%s: missing dependencies property", f->name);
949 		return;
950 	}
951 
952 	nr_deps = len / sizeof(int);
953 
954 	for (i = 0; i < nr_deps; i++) {
955 		unsigned long phandle = be32_to_cpu(prop[i]);
956 		int j;
957 
958 		for (j = 0; j < nr_dt_cpu_features; j++) {
959 			struct dt_cpu_feature *d = &dt_cpu_features[j];
960 
961 			if (of_get_flat_dt_phandle(d->node) == phandle) {
962 				cpufeatures_deps_enable(d);
963 				if (d->disabled) {
964 					f->disabled = 1;
965 					return;
966 				}
967 			}
968 		}
969 	}
970 
971 	if (cpufeatures_process_feature(f))
972 		f->enabled = 1;
973 	else
974 		f->disabled = 1;
975 }
976 
977 static int __init scan_cpufeatures_subnodes(unsigned long node,
978 					  const char *uname,
979 					  void *data)
980 {
981 	int *count = data;
982 
983 	process_cpufeatures_node(node, uname, *count);
984 
985 	(*count)++;
986 
987 	return 0;
988 }
989 
990 static int __init count_cpufeatures_subnodes(unsigned long node,
991 					  const char *uname,
992 					  void *data)
993 {
994 	int *count = data;
995 
996 	(*count)++;
997 
998 	return 0;
999 }
1000 
1001 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
1002 					    *uname, int depth, void *data)
1003 {
1004 	const __be32 *prop;
1005 	int count, i;
1006 	u32 isa;
1007 
1008 	/* We are scanning "ibm,powerpc-cpu-features" nodes only */
1009 	if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
1010 		return 0;
1011 
1012 	prop = of_get_flat_dt_prop(node, "isa", NULL);
1013 	if (!prop)
1014 		/* We checked before, "can't happen" */
1015 		return 0;
1016 
1017 	isa = be32_to_cpup(prop);
1018 
1019 	/* Count and allocate space for cpu features */
1020 	of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
1021 						&nr_dt_cpu_features);
1022 	dt_cpu_features = __va(
1023 		memblock_alloc(sizeof(struct dt_cpu_feature)*
1024 				nr_dt_cpu_features, PAGE_SIZE));
1025 
1026 	cpufeatures_setup_start(isa);
1027 
1028 	/* Scan nodes into dt_cpu_features and enable those without deps  */
1029 	count = 0;
1030 	of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
1031 
1032 	/* Recursive enable remaining features with dependencies */
1033 	for (i = 0; i < nr_dt_cpu_features; i++) {
1034 		struct dt_cpu_feature *f = &dt_cpu_features[i];
1035 
1036 		cpufeatures_deps_enable(f);
1037 	}
1038 
1039 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
1040 	if (prop && strlen((char *)prop) != 0) {
1041 		strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
1042 		cur_cpu_spec->cpu_name = dt_cpu_name;
1043 	}
1044 
1045 	cpufeatures_setup_finished();
1046 
1047 	memblock_free(__pa(dt_cpu_features),
1048 			sizeof(struct dt_cpu_feature)*nr_dt_cpu_features);
1049 
1050 	return 0;
1051 }
1052 
1053 void __init dt_cpu_ftrs_scan(void)
1054 {
1055 	if (!using_dt_cpu_ftrs)
1056 		return;
1057 
1058 	of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
1059 }
1060