xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision fbb6b31a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Processor capabilities determination functions.
4  *
5  * Copyright (C) xxxx  the Anonymous
6  * Copyright (C) 1994 - 2006 Ralf Baechle
7  * Copyright (C) 2003, 2004  Maciej W. Rozycki
8  * Copyright (C) 2001, 2004, 2011, 2012	 MIPS Technologies, Inc.
9  */
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/ptrace.h>
13 #include <linux/smp.h>
14 #include <linux/stddef.h>
15 #include <linux/export.h>
16 
17 #include <asm/bugs.h>
18 #include <asm/cpu.h>
19 #include <asm/cpu-features.h>
20 #include <asm/cpu-type.h>
21 #include <asm/fpu.h>
22 #include <asm/mipsregs.h>
23 #include <asm/mipsmtregs.h>
24 #include <asm/msa.h>
25 #include <asm/watch.h>
26 #include <asm/elf.h>
27 #include <asm/pgtable-bits.h>
28 #include <asm/spram.h>
29 #include <asm/traps.h>
30 #include <linux/uaccess.h>
31 
32 #include "fpu-probe.h"
33 
34 #include <asm/mach-loongson64/cpucfg-emul.h>
35 
36 /* Hardware capabilities */
37 unsigned int elf_hwcap __read_mostly;
38 EXPORT_SYMBOL_GPL(elf_hwcap);
39 
40 static inline unsigned long cpu_get_msa_id(void)
41 {
42 	unsigned long status, msa_id;
43 
44 	status = read_c0_status();
45 	__enable_fpu(FPU_64BIT);
46 	enable_msa();
47 	msa_id = read_msa_ir();
48 	disable_msa();
49 	write_c0_status(status);
50 	return msa_id;
51 }
52 
53 static int mips_dsp_disabled;
54 
55 static int __init dsp_disable(char *s)
56 {
57 	cpu_data[0].ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
58 	mips_dsp_disabled = 1;
59 
60 	return 1;
61 }
62 
63 __setup("nodsp", dsp_disable);
64 
65 static int mips_htw_disabled;
66 
67 static int __init htw_disable(char *s)
68 {
69 	mips_htw_disabled = 1;
70 	cpu_data[0].options &= ~MIPS_CPU_HTW;
71 	write_c0_pwctl(read_c0_pwctl() &
72 		       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
73 
74 	return 1;
75 }
76 
77 __setup("nohtw", htw_disable);
78 
79 static int mips_ftlb_disabled;
80 static int mips_has_ftlb_configured;
81 
82 enum ftlb_flags {
83 	FTLB_EN		= 1 << 0,
84 	FTLB_SET_PROB	= 1 << 1,
85 };
86 
87 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags);
88 
89 static int __init ftlb_disable(char *s)
90 {
91 	unsigned int config4, mmuextdef;
92 
93 	/*
94 	 * If the core hasn't done any FTLB configuration, there is nothing
95 	 * for us to do here.
96 	 */
97 	if (!mips_has_ftlb_configured)
98 		return 1;
99 
100 	/* Disable it in the boot cpu */
101 	if (set_ftlb_enable(&cpu_data[0], 0)) {
102 		pr_warn("Can't turn FTLB off\n");
103 		return 1;
104 	}
105 
106 	config4 = read_c0_config4();
107 
108 	/* Check that FTLB has been disabled */
109 	mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
110 	/* MMUSIZEEXT == VTLB ON, FTLB OFF */
111 	if (mmuextdef == MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT) {
112 		/* This should never happen */
113 		pr_warn("FTLB could not be disabled!\n");
114 		return 1;
115 	}
116 
117 	mips_ftlb_disabled = 1;
118 	mips_has_ftlb_configured = 0;
119 
120 	/*
121 	 * noftlb is mainly used for debug purposes so print
122 	 * an informative message instead of using pr_debug()
123 	 */
124 	pr_info("FTLB has been disabled\n");
125 
126 	/*
127 	 * Some of these bits are duplicated in the decode_config4.
128 	 * MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT is the only possible case
129 	 * once FTLB has been disabled so undo what decode_config4 did.
130 	 */
131 	cpu_data[0].tlbsize -= cpu_data[0].tlbsizeftlbways *
132 			       cpu_data[0].tlbsizeftlbsets;
133 	cpu_data[0].tlbsizeftlbsets = 0;
134 	cpu_data[0].tlbsizeftlbways = 0;
135 
136 	return 1;
137 }
138 
139 __setup("noftlb", ftlb_disable);
140 
141 /*
142  * Check if the CPU has per tc perf counters
143  */
144 static inline void cpu_set_mt_per_tc_perf(struct cpuinfo_mips *c)
145 {
146 	if (read_c0_config7() & MTI_CONF7_PTC)
147 		c->options |= MIPS_CPU_MT_PER_TC_PERF_COUNTERS;
148 }
149 
150 static inline void check_errata(void)
151 {
152 	struct cpuinfo_mips *c = &current_cpu_data;
153 
154 	switch (current_cpu_type()) {
155 	case CPU_34K:
156 		/*
157 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
158 		 * This code only handles VPE0, any SMP/RTOS code
159 		 * making use of VPE1 will be responsable for that VPE.
160 		 */
161 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
162 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
163 		break;
164 	default:
165 		break;
166 	}
167 }
168 
169 void __init check_bugs32(void)
170 {
171 	check_errata();
172 }
173 
174 /*
175  * Probe whether cpu has config register by trying to play with
176  * alternate cache bit and see whether it matters.
177  * It's used by cpu_probe to distinguish between R3000A and R3081.
178  */
179 static inline int cpu_has_confreg(void)
180 {
181 #ifdef CONFIG_CPU_R3000
182 	extern unsigned long r3k_cache_size(unsigned long);
183 	unsigned long size1, size2;
184 	unsigned long cfg = read_c0_conf();
185 
186 	size1 = r3k_cache_size(ST0_ISC);
187 	write_c0_conf(cfg ^ R30XX_CONF_AC);
188 	size2 = r3k_cache_size(ST0_ISC);
189 	write_c0_conf(cfg);
190 	return size1 != size2;
191 #else
192 	return 0;
193 #endif
194 }
195 
196 static inline void set_elf_platform(int cpu, const char *plat)
197 {
198 	if (cpu == 0)
199 		__elf_platform = plat;
200 }
201 
202 static inline void set_elf_base_platform(const char *plat)
203 {
204 	if (__elf_base_platform == NULL) {
205 		__elf_base_platform = plat;
206 	}
207 }
208 
209 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
210 {
211 #ifdef __NEED_VMBITS_PROBE
212 	write_c0_entryhi(0x3fffffffffffe000ULL);
213 	back_to_back_c0_hazard();
214 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
215 #endif
216 }
217 
218 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
219 {
220 	switch (isa) {
221 	case MIPS_CPU_ISA_M64R5:
222 		c->isa_level |= MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5;
223 		set_elf_base_platform("mips64r5");
224 		fallthrough;
225 	case MIPS_CPU_ISA_M64R2:
226 		c->isa_level |= MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2;
227 		set_elf_base_platform("mips64r2");
228 		fallthrough;
229 	case MIPS_CPU_ISA_M64R1:
230 		c->isa_level |= MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1;
231 		set_elf_base_platform("mips64");
232 		fallthrough;
233 	case MIPS_CPU_ISA_V:
234 		c->isa_level |= MIPS_CPU_ISA_V;
235 		set_elf_base_platform("mips5");
236 		fallthrough;
237 	case MIPS_CPU_ISA_IV:
238 		c->isa_level |= MIPS_CPU_ISA_IV;
239 		set_elf_base_platform("mips4");
240 		fallthrough;
241 	case MIPS_CPU_ISA_III:
242 		c->isa_level |= MIPS_CPU_ISA_II | MIPS_CPU_ISA_III;
243 		set_elf_base_platform("mips3");
244 		break;
245 
246 	/* R6 incompatible with everything else */
247 	case MIPS_CPU_ISA_M64R6:
248 		c->isa_level |= MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6;
249 		set_elf_base_platform("mips64r6");
250 		fallthrough;
251 	case MIPS_CPU_ISA_M32R6:
252 		c->isa_level |= MIPS_CPU_ISA_M32R6;
253 		set_elf_base_platform("mips32r6");
254 		/* Break here so we don't add incompatible ISAs */
255 		break;
256 	case MIPS_CPU_ISA_M32R5:
257 		c->isa_level |= MIPS_CPU_ISA_M32R5;
258 		set_elf_base_platform("mips32r5");
259 		fallthrough;
260 	case MIPS_CPU_ISA_M32R2:
261 		c->isa_level |= MIPS_CPU_ISA_M32R2;
262 		set_elf_base_platform("mips32r2");
263 		fallthrough;
264 	case MIPS_CPU_ISA_M32R1:
265 		c->isa_level |= MIPS_CPU_ISA_M32R1;
266 		set_elf_base_platform("mips32");
267 		fallthrough;
268 	case MIPS_CPU_ISA_II:
269 		c->isa_level |= MIPS_CPU_ISA_II;
270 		set_elf_base_platform("mips2");
271 		break;
272 	}
273 }
274 
275 static char unknown_isa[] = KERN_ERR \
276 	"Unsupported ISA type, c0.config0: %d.";
277 
278 static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
279 {
280 
281 	unsigned int probability = c->tlbsize / c->tlbsizevtlb;
282 
283 	/*
284 	 * 0 = All TLBWR instructions go to FTLB
285 	 * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
286 	 * FTLB and 1 goes to the VTLB.
287 	 * 2 = 7:1: As above with 7:1 ratio.
288 	 * 3 = 3:1: As above with 3:1 ratio.
289 	 *
290 	 * Use the linear midpoint as the probability threshold.
291 	 */
292 	if (probability >= 12)
293 		return 1;
294 	else if (probability >= 6)
295 		return 2;
296 	else
297 		/*
298 		 * So FTLB is less than 4 times bigger than VTLB.
299 		 * A 3:1 ratio can still be useful though.
300 		 */
301 		return 3;
302 }
303 
304 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags)
305 {
306 	unsigned int config;
307 
308 	/* It's implementation dependent how the FTLB can be enabled */
309 	switch (c->cputype) {
310 	case CPU_PROAPTIV:
311 	case CPU_P5600:
312 	case CPU_P6600:
313 		/* proAptiv & related cores use Config6 to enable the FTLB */
314 		config = read_c0_config6();
315 
316 		if (flags & FTLB_EN)
317 			config |= MTI_CONF6_FTLBEN;
318 		else
319 			config &= ~MTI_CONF6_FTLBEN;
320 
321 		if (flags & FTLB_SET_PROB) {
322 			config &= ~(3 << MTI_CONF6_FTLBP_SHIFT);
323 			config |= calculate_ftlb_probability(c)
324 				  << MTI_CONF6_FTLBP_SHIFT;
325 		}
326 
327 		write_c0_config6(config);
328 		back_to_back_c0_hazard();
329 		break;
330 	case CPU_I6400:
331 	case CPU_I6500:
332 		/* There's no way to disable the FTLB */
333 		if (!(flags & FTLB_EN))
334 			return 1;
335 		return 0;
336 	case CPU_LOONGSON64:
337 		/* Flush ITLB, DTLB, VTLB and FTLB */
338 		write_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB |
339 			      LOONGSON_DIAG_VTLB | LOONGSON_DIAG_FTLB);
340 		/* Loongson-3 cores use Config6 to enable the FTLB */
341 		config = read_c0_config6();
342 		if (flags & FTLB_EN)
343 			/* Enable FTLB */
344 			write_c0_config6(config & ~LOONGSON_CONF6_FTLBDIS);
345 		else
346 			/* Disable FTLB */
347 			write_c0_config6(config | LOONGSON_CONF6_FTLBDIS);
348 		break;
349 	default:
350 		return 1;
351 	}
352 
353 	return 0;
354 }
355 
356 static int mm_config(struct cpuinfo_mips *c)
357 {
358 	unsigned int config0, update, mm;
359 
360 	config0 = read_c0_config();
361 	mm = config0 & MIPS_CONF_MM;
362 
363 	/*
364 	 * It's implementation dependent what type of write-merge is supported
365 	 * and whether it can be enabled/disabled. If it is settable lets make
366 	 * the merging allowed by default. Some platforms might have
367 	 * write-through caching unsupported. In this case just ignore the
368 	 * CP0.Config.MM bit field value.
369 	 */
370 	switch (c->cputype) {
371 	case CPU_24K:
372 	case CPU_34K:
373 	case CPU_74K:
374 	case CPU_P5600:
375 	case CPU_P6600:
376 		c->options |= MIPS_CPU_MM_FULL;
377 		update = MIPS_CONF_MM_FULL;
378 		break;
379 	case CPU_1004K:
380 	case CPU_1074K:
381 	case CPU_INTERAPTIV:
382 	case CPU_PROAPTIV:
383 		mm = 0;
384 		fallthrough;
385 	default:
386 		update = 0;
387 		break;
388 	}
389 
390 	if (update) {
391 		config0 = (config0 & ~MIPS_CONF_MM) | update;
392 		write_c0_config(config0);
393 	} else if (mm == MIPS_CONF_MM_SYSAD) {
394 		c->options |= MIPS_CPU_MM_SYSAD;
395 	} else if (mm == MIPS_CONF_MM_FULL) {
396 		c->options |= MIPS_CPU_MM_FULL;
397 	}
398 
399 	return 0;
400 }
401 
402 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
403 {
404 	unsigned int config0;
405 	int isa, mt;
406 
407 	config0 = read_c0_config();
408 
409 	/*
410 	 * Look for Standard TLB or Dual VTLB and FTLB
411 	 */
412 	mt = config0 & MIPS_CONF_MT;
413 	if (mt == MIPS_CONF_MT_TLB)
414 		c->options |= MIPS_CPU_TLB;
415 	else if (mt == MIPS_CONF_MT_FTLB)
416 		c->options |= MIPS_CPU_TLB | MIPS_CPU_FTLB;
417 
418 	isa = (config0 & MIPS_CONF_AT) >> 13;
419 	switch (isa) {
420 	case 0:
421 		switch ((config0 & MIPS_CONF_AR) >> 10) {
422 		case 0:
423 			set_isa(c, MIPS_CPU_ISA_M32R1);
424 			break;
425 		case 1:
426 			set_isa(c, MIPS_CPU_ISA_M32R2);
427 			break;
428 		case 2:
429 			set_isa(c, MIPS_CPU_ISA_M32R6);
430 			break;
431 		default:
432 			goto unknown;
433 		}
434 		break;
435 	case 2:
436 		switch ((config0 & MIPS_CONF_AR) >> 10) {
437 		case 0:
438 			set_isa(c, MIPS_CPU_ISA_M64R1);
439 			break;
440 		case 1:
441 			set_isa(c, MIPS_CPU_ISA_M64R2);
442 			break;
443 		case 2:
444 			set_isa(c, MIPS_CPU_ISA_M64R6);
445 			break;
446 		default:
447 			goto unknown;
448 		}
449 		break;
450 	default:
451 		goto unknown;
452 	}
453 
454 	return config0 & MIPS_CONF_M;
455 
456 unknown:
457 	panic(unknown_isa, config0);
458 }
459 
460 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
461 {
462 	unsigned int config1;
463 
464 	config1 = read_c0_config1();
465 
466 	if (config1 & MIPS_CONF1_MD)
467 		c->ases |= MIPS_ASE_MDMX;
468 	if (config1 & MIPS_CONF1_PC)
469 		c->options |= MIPS_CPU_PERF;
470 	if (config1 & MIPS_CONF1_WR)
471 		c->options |= MIPS_CPU_WATCH;
472 	if (config1 & MIPS_CONF1_CA)
473 		c->ases |= MIPS_ASE_MIPS16;
474 	if (config1 & MIPS_CONF1_EP)
475 		c->options |= MIPS_CPU_EJTAG;
476 	if (config1 & MIPS_CONF1_FP) {
477 		c->options |= MIPS_CPU_FPU;
478 		c->options |= MIPS_CPU_32FPR;
479 	}
480 	if (cpu_has_tlb) {
481 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
482 		c->tlbsizevtlb = c->tlbsize;
483 		c->tlbsizeftlbsets = 0;
484 	}
485 
486 	return config1 & MIPS_CONF_M;
487 }
488 
489 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
490 {
491 	unsigned int config2;
492 
493 	config2 = read_c0_config2();
494 
495 	if (config2 & MIPS_CONF2_SL)
496 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
497 
498 	return config2 & MIPS_CONF_M;
499 }
500 
501 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
502 {
503 	unsigned int config3;
504 
505 	config3 = read_c0_config3();
506 
507 	if (config3 & MIPS_CONF3_SM) {
508 		c->ases |= MIPS_ASE_SMARTMIPS;
509 		c->options |= MIPS_CPU_RIXI | MIPS_CPU_CTXTC;
510 	}
511 	if (config3 & MIPS_CONF3_RXI)
512 		c->options |= MIPS_CPU_RIXI;
513 	if (config3 & MIPS_CONF3_CTXTC)
514 		c->options |= MIPS_CPU_CTXTC;
515 	if (config3 & MIPS_CONF3_DSP)
516 		c->ases |= MIPS_ASE_DSP;
517 	if (config3 & MIPS_CONF3_DSP2P) {
518 		c->ases |= MIPS_ASE_DSP2P;
519 		if (cpu_has_mips_r6)
520 			c->ases |= MIPS_ASE_DSP3;
521 	}
522 	if (config3 & MIPS_CONF3_VINT)
523 		c->options |= MIPS_CPU_VINT;
524 	if (config3 & MIPS_CONF3_VEIC)
525 		c->options |= MIPS_CPU_VEIC;
526 	if (config3 & MIPS_CONF3_LPA)
527 		c->options |= MIPS_CPU_LPA;
528 	if (config3 & MIPS_CONF3_MT)
529 		c->ases |= MIPS_ASE_MIPSMT;
530 	if (config3 & MIPS_CONF3_ULRI)
531 		c->options |= MIPS_CPU_ULRI;
532 	if (config3 & MIPS_CONF3_ISA)
533 		c->options |= MIPS_CPU_MICROMIPS;
534 	if (config3 & MIPS_CONF3_VZ)
535 		c->ases |= MIPS_ASE_VZ;
536 	if (config3 & MIPS_CONF3_SC)
537 		c->options |= MIPS_CPU_SEGMENTS;
538 	if (config3 & MIPS_CONF3_BI)
539 		c->options |= MIPS_CPU_BADINSTR;
540 	if (config3 & MIPS_CONF3_BP)
541 		c->options |= MIPS_CPU_BADINSTRP;
542 	if (config3 & MIPS_CONF3_MSA)
543 		c->ases |= MIPS_ASE_MSA;
544 	if (config3 & MIPS_CONF3_PW) {
545 		c->htw_seq = 0;
546 		c->options |= MIPS_CPU_HTW;
547 	}
548 	if (config3 & MIPS_CONF3_CDMM)
549 		c->options |= MIPS_CPU_CDMM;
550 	if (config3 & MIPS_CONF3_SP)
551 		c->options |= MIPS_CPU_SP;
552 
553 	return config3 & MIPS_CONF_M;
554 }
555 
556 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
557 {
558 	unsigned int config4;
559 	unsigned int newcf4;
560 	unsigned int mmuextdef;
561 	unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE;
562 	unsigned long asid_mask;
563 
564 	config4 = read_c0_config4();
565 
566 	if (cpu_has_tlb) {
567 		if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
568 			c->options |= MIPS_CPU_TLBINV;
569 
570 		/*
571 		 * R6 has dropped the MMUExtDef field from config4.
572 		 * On R6 the fields always describe the FTLB, and only if it is
573 		 * present according to Config.MT.
574 		 */
575 		if (!cpu_has_mips_r6)
576 			mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
577 		else if (cpu_has_ftlb)
578 			mmuextdef = MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT;
579 		else
580 			mmuextdef = 0;
581 
582 		switch (mmuextdef) {
583 		case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT:
584 			c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
585 			c->tlbsizevtlb = c->tlbsize;
586 			break;
587 		case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
588 			c->tlbsizevtlb +=
589 				((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
590 				  MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40;
591 			c->tlbsize = c->tlbsizevtlb;
592 			ftlb_page = MIPS_CONF4_VFTLBPAGESIZE;
593 			fallthrough;
594 		case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
595 			if (mips_ftlb_disabled)
596 				break;
597 			newcf4 = (config4 & ~ftlb_page) |
598 				(page_size_ftlb(mmuextdef) <<
599 				 MIPS_CONF4_FTLBPAGESIZE_SHIFT);
600 			write_c0_config4(newcf4);
601 			back_to_back_c0_hazard();
602 			config4 = read_c0_config4();
603 			if (config4 != newcf4) {
604 				pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n",
605 				       PAGE_SIZE, config4);
606 				/* Switch FTLB off */
607 				set_ftlb_enable(c, 0);
608 				mips_ftlb_disabled = 1;
609 				break;
610 			}
611 			c->tlbsizeftlbsets = 1 <<
612 				((config4 & MIPS_CONF4_FTLBSETS) >>
613 				 MIPS_CONF4_FTLBSETS_SHIFT);
614 			c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >>
615 					      MIPS_CONF4_FTLBWAYS_SHIFT) + 2;
616 			c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets;
617 			mips_has_ftlb_configured = 1;
618 			break;
619 		}
620 	}
621 
622 	c->kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
623 				>> MIPS_CONF4_KSCREXIST_SHIFT;
624 
625 	asid_mask = MIPS_ENTRYHI_ASID;
626 	if (config4 & MIPS_CONF4_AE)
627 		asid_mask |= MIPS_ENTRYHI_ASIDX;
628 	set_cpu_asid_mask(c, asid_mask);
629 
630 	/*
631 	 * Warn if the computed ASID mask doesn't match the mask the kernel
632 	 * is built for. This may indicate either a serious problem or an
633 	 * easy optimisation opportunity, but either way should be addressed.
634 	 */
635 	WARN_ON(asid_mask != cpu_asid_mask(c));
636 
637 	return config4 & MIPS_CONF_M;
638 }
639 
640 static inline unsigned int decode_config5(struct cpuinfo_mips *c)
641 {
642 	unsigned int config5, max_mmid_width;
643 	unsigned long asid_mask;
644 
645 	config5 = read_c0_config5();
646 	config5 &= ~(MIPS_CONF5_UFR | MIPS_CONF5_UFE);
647 
648 	if (cpu_has_mips_r6) {
649 		if (!__builtin_constant_p(cpu_has_mmid) || cpu_has_mmid)
650 			config5 |= MIPS_CONF5_MI;
651 		else
652 			config5 &= ~MIPS_CONF5_MI;
653 	}
654 
655 	write_c0_config5(config5);
656 
657 	if (config5 & MIPS_CONF5_EVA)
658 		c->options |= MIPS_CPU_EVA;
659 	if (config5 & MIPS_CONF5_MRP)
660 		c->options |= MIPS_CPU_MAAR;
661 	if (config5 & MIPS_CONF5_LLB)
662 		c->options |= MIPS_CPU_RW_LLB;
663 	if (config5 & MIPS_CONF5_MVH)
664 		c->options |= MIPS_CPU_MVH;
665 	if (cpu_has_mips_r6 && (config5 & MIPS_CONF5_VP))
666 		c->options |= MIPS_CPU_VP;
667 	if (config5 & MIPS_CONF5_CA2)
668 		c->ases |= MIPS_ASE_MIPS16E2;
669 
670 	if (config5 & MIPS_CONF5_CRCP)
671 		elf_hwcap |= HWCAP_MIPS_CRC32;
672 
673 	if (cpu_has_mips_r6) {
674 		/* Ensure the write to config5 above takes effect */
675 		back_to_back_c0_hazard();
676 
677 		/* Check whether we successfully enabled MMID support */
678 		config5 = read_c0_config5();
679 		if (config5 & MIPS_CONF5_MI)
680 			c->options |= MIPS_CPU_MMID;
681 
682 		/*
683 		 * Warn if we've hardcoded cpu_has_mmid to a value unsuitable
684 		 * for the CPU we're running on, or if CPUs in an SMP system
685 		 * have inconsistent MMID support.
686 		 */
687 		WARN_ON(!!cpu_has_mmid != !!(config5 & MIPS_CONF5_MI));
688 
689 		if (cpu_has_mmid) {
690 			write_c0_memorymapid(~0ul);
691 			back_to_back_c0_hazard();
692 			asid_mask = read_c0_memorymapid();
693 
694 			/*
695 			 * We maintain a bitmap to track MMID allocation, and
696 			 * need a sensible upper bound on the size of that
697 			 * bitmap. The initial CPU with MMID support (I6500)
698 			 * supports 16 bit MMIDs, which gives us an 8KiB
699 			 * bitmap. The architecture recommends that hardware
700 			 * support 32 bit MMIDs, which would give us a 512MiB
701 			 * bitmap - that's too big in most cases.
702 			 *
703 			 * Cap MMID width at 16 bits for now & we can revisit
704 			 * this if & when hardware supports anything wider.
705 			 */
706 			max_mmid_width = 16;
707 			if (asid_mask > GENMASK(max_mmid_width - 1, 0)) {
708 				pr_info("Capping MMID width at %d bits",
709 					max_mmid_width);
710 				asid_mask = GENMASK(max_mmid_width - 1, 0);
711 			}
712 
713 			set_cpu_asid_mask(c, asid_mask);
714 		}
715 	}
716 
717 	return config5 & MIPS_CONF_M;
718 }
719 
720 static void decode_configs(struct cpuinfo_mips *c)
721 {
722 	int ok;
723 
724 	/* MIPS32 or MIPS64 compliant CPU.  */
725 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
726 		     MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
727 
728 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
729 
730 	/* Enable FTLB if present and not disabled */
731 	set_ftlb_enable(c, mips_ftlb_disabled ? 0 : FTLB_EN);
732 
733 	ok = decode_config0(c);			/* Read Config registers.  */
734 	BUG_ON(!ok);				/* Arch spec violation!	 */
735 	if (ok)
736 		ok = decode_config1(c);
737 	if (ok)
738 		ok = decode_config2(c);
739 	if (ok)
740 		ok = decode_config3(c);
741 	if (ok)
742 		ok = decode_config4(c);
743 	if (ok)
744 		ok = decode_config5(c);
745 
746 	/* Probe the EBase.WG bit */
747 	if (cpu_has_mips_r2_r6) {
748 		u64 ebase;
749 		unsigned int status;
750 
751 		/* {read,write}_c0_ebase_64() may be UNDEFINED prior to r6 */
752 		ebase = cpu_has_mips64r6 ? read_c0_ebase_64()
753 					 : (s32)read_c0_ebase();
754 		if (ebase & MIPS_EBASE_WG) {
755 			/* WG bit already set, we can avoid the clumsy probe */
756 			c->options |= MIPS_CPU_EBASE_WG;
757 		} else {
758 			/* Its UNDEFINED to change EBase while BEV=0 */
759 			status = read_c0_status();
760 			write_c0_status(status | ST0_BEV);
761 			irq_enable_hazard();
762 			/*
763 			 * On pre-r6 cores, this may well clobber the upper bits
764 			 * of EBase. This is hard to avoid without potentially
765 			 * hitting UNDEFINED dm*c0 behaviour if EBase is 32-bit.
766 			 */
767 			if (cpu_has_mips64r6)
768 				write_c0_ebase_64(ebase | MIPS_EBASE_WG);
769 			else
770 				write_c0_ebase(ebase | MIPS_EBASE_WG);
771 			back_to_back_c0_hazard();
772 			/* Restore BEV */
773 			write_c0_status(status);
774 			if (read_c0_ebase() & MIPS_EBASE_WG) {
775 				c->options |= MIPS_CPU_EBASE_WG;
776 				write_c0_ebase(ebase);
777 			}
778 		}
779 	}
780 
781 	/* configure the FTLB write probability */
782 	set_ftlb_enable(c, (mips_ftlb_disabled ? 0 : FTLB_EN) | FTLB_SET_PROB);
783 
784 	mips_probe_watch_registers(c);
785 
786 #ifndef CONFIG_MIPS_CPS
787 	if (cpu_has_mips_r2_r6) {
788 		unsigned int core;
789 
790 		core = get_ebase_cpunum();
791 		if (cpu_has_mipsmt)
792 			core >>= fls(core_nvpes()) - 1;
793 		cpu_set_core(c, core);
794 	}
795 #endif
796 }
797 
798 /*
799  * Probe for certain guest capabilities by writing config bits and reading back.
800  * Finally write back the original value.
801  */
802 #define probe_gc0_config(name, maxconf, bits)				\
803 do {									\
804 	unsigned int tmp;						\
805 	tmp = read_gc0_##name();					\
806 	write_gc0_##name(tmp | (bits));					\
807 	back_to_back_c0_hazard();					\
808 	maxconf = read_gc0_##name();					\
809 	write_gc0_##name(tmp);						\
810 } while (0)
811 
812 /*
813  * Probe for dynamic guest capabilities by changing certain config bits and
814  * reading back to see if they change. Finally write back the original value.
815  */
816 #define probe_gc0_config_dyn(name, maxconf, dynconf, bits)		\
817 do {									\
818 	maxconf = read_gc0_##name();					\
819 	write_gc0_##name(maxconf ^ (bits));				\
820 	back_to_back_c0_hazard();					\
821 	dynconf = maxconf ^ read_gc0_##name();				\
822 	write_gc0_##name(maxconf);					\
823 	maxconf |= dynconf;						\
824 } while (0)
825 
826 static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c)
827 {
828 	unsigned int config0;
829 
830 	probe_gc0_config(config, config0, MIPS_CONF_M);
831 
832 	if (config0 & MIPS_CONF_M)
833 		c->guest.conf |= BIT(1);
834 	return config0 & MIPS_CONF_M;
835 }
836 
837 static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c)
838 {
839 	unsigned int config1, config1_dyn;
840 
841 	probe_gc0_config_dyn(config1, config1, config1_dyn,
842 			     MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR |
843 			     MIPS_CONF1_FP);
844 
845 	if (config1 & MIPS_CONF1_FP)
846 		c->guest.options |= MIPS_CPU_FPU;
847 	if (config1_dyn & MIPS_CONF1_FP)
848 		c->guest.options_dyn |= MIPS_CPU_FPU;
849 
850 	if (config1 & MIPS_CONF1_WR)
851 		c->guest.options |= MIPS_CPU_WATCH;
852 	if (config1_dyn & MIPS_CONF1_WR)
853 		c->guest.options_dyn |= MIPS_CPU_WATCH;
854 
855 	if (config1 & MIPS_CONF1_PC)
856 		c->guest.options |= MIPS_CPU_PERF;
857 	if (config1_dyn & MIPS_CONF1_PC)
858 		c->guest.options_dyn |= MIPS_CPU_PERF;
859 
860 	if (config1 & MIPS_CONF_M)
861 		c->guest.conf |= BIT(2);
862 	return config1 & MIPS_CONF_M;
863 }
864 
865 static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c)
866 {
867 	unsigned int config2;
868 
869 	probe_gc0_config(config2, config2, MIPS_CONF_M);
870 
871 	if (config2 & MIPS_CONF_M)
872 		c->guest.conf |= BIT(3);
873 	return config2 & MIPS_CONF_M;
874 }
875 
876 static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c)
877 {
878 	unsigned int config3, config3_dyn;
879 
880 	probe_gc0_config_dyn(config3, config3, config3_dyn,
881 			     MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_ULRI |
882 			     MIPS_CONF3_CTXTC);
883 
884 	if (config3 & MIPS_CONF3_CTXTC)
885 		c->guest.options |= MIPS_CPU_CTXTC;
886 	if (config3_dyn & MIPS_CONF3_CTXTC)
887 		c->guest.options_dyn |= MIPS_CPU_CTXTC;
888 
889 	if (config3 & MIPS_CONF3_PW)
890 		c->guest.options |= MIPS_CPU_HTW;
891 
892 	if (config3 & MIPS_CONF3_ULRI)
893 		c->guest.options |= MIPS_CPU_ULRI;
894 
895 	if (config3 & MIPS_CONF3_SC)
896 		c->guest.options |= MIPS_CPU_SEGMENTS;
897 
898 	if (config3 & MIPS_CONF3_BI)
899 		c->guest.options |= MIPS_CPU_BADINSTR;
900 	if (config3 & MIPS_CONF3_BP)
901 		c->guest.options |= MIPS_CPU_BADINSTRP;
902 
903 	if (config3 & MIPS_CONF3_MSA)
904 		c->guest.ases |= MIPS_ASE_MSA;
905 	if (config3_dyn & MIPS_CONF3_MSA)
906 		c->guest.ases_dyn |= MIPS_ASE_MSA;
907 
908 	if (config3 & MIPS_CONF_M)
909 		c->guest.conf |= BIT(4);
910 	return config3 & MIPS_CONF_M;
911 }
912 
913 static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c)
914 {
915 	unsigned int config4;
916 
917 	probe_gc0_config(config4, config4,
918 			 MIPS_CONF_M | MIPS_CONF4_KSCREXIST);
919 
920 	c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
921 				>> MIPS_CONF4_KSCREXIST_SHIFT;
922 
923 	if (config4 & MIPS_CONF_M)
924 		c->guest.conf |= BIT(5);
925 	return config4 & MIPS_CONF_M;
926 }
927 
928 static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c)
929 {
930 	unsigned int config5, config5_dyn;
931 
932 	probe_gc0_config_dyn(config5, config5, config5_dyn,
933 			 MIPS_CONF_M | MIPS_CONF5_MVH | MIPS_CONF5_MRP);
934 
935 	if (config5 & MIPS_CONF5_MRP)
936 		c->guest.options |= MIPS_CPU_MAAR;
937 	if (config5_dyn & MIPS_CONF5_MRP)
938 		c->guest.options_dyn |= MIPS_CPU_MAAR;
939 
940 	if (config5 & MIPS_CONF5_LLB)
941 		c->guest.options |= MIPS_CPU_RW_LLB;
942 
943 	if (config5 & MIPS_CONF5_MVH)
944 		c->guest.options |= MIPS_CPU_MVH;
945 
946 	if (config5 & MIPS_CONF_M)
947 		c->guest.conf |= BIT(6);
948 	return config5 & MIPS_CONF_M;
949 }
950 
951 static inline void decode_guest_configs(struct cpuinfo_mips *c)
952 {
953 	unsigned int ok;
954 
955 	ok = decode_guest_config0(c);
956 	if (ok)
957 		ok = decode_guest_config1(c);
958 	if (ok)
959 		ok = decode_guest_config2(c);
960 	if (ok)
961 		ok = decode_guest_config3(c);
962 	if (ok)
963 		ok = decode_guest_config4(c);
964 	if (ok)
965 		decode_guest_config5(c);
966 }
967 
968 static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c)
969 {
970 	unsigned int guestctl0, temp;
971 
972 	guestctl0 = read_c0_guestctl0();
973 
974 	if (guestctl0 & MIPS_GCTL0_G0E)
975 		c->options |= MIPS_CPU_GUESTCTL0EXT;
976 	if (guestctl0 & MIPS_GCTL0_G1)
977 		c->options |= MIPS_CPU_GUESTCTL1;
978 	if (guestctl0 & MIPS_GCTL0_G2)
979 		c->options |= MIPS_CPU_GUESTCTL2;
980 	if (!(guestctl0 & MIPS_GCTL0_RAD)) {
981 		c->options |= MIPS_CPU_GUESTID;
982 
983 		/*
984 		 * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0
985 		 * first, otherwise all data accesses will be fully virtualised
986 		 * as if they were performed by guest mode.
987 		 */
988 		write_c0_guestctl1(0);
989 		tlbw_use_hazard();
990 
991 		write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG);
992 		back_to_back_c0_hazard();
993 		temp = read_c0_guestctl0();
994 
995 		if (temp & MIPS_GCTL0_DRG) {
996 			write_c0_guestctl0(guestctl0);
997 			c->options |= MIPS_CPU_DRG;
998 		}
999 	}
1000 }
1001 
1002 static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c)
1003 {
1004 	if (cpu_has_guestid) {
1005 		/* determine the number of bits of GuestID available */
1006 		write_c0_guestctl1(MIPS_GCTL1_ID);
1007 		back_to_back_c0_hazard();
1008 		c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID)
1009 						>> MIPS_GCTL1_ID_SHIFT;
1010 		write_c0_guestctl1(0);
1011 	}
1012 }
1013 
1014 static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c)
1015 {
1016 	/* determine the number of bits of GTOffset available */
1017 	write_c0_gtoffset(0xffffffff);
1018 	back_to_back_c0_hazard();
1019 	c->gtoffset_mask = read_c0_gtoffset();
1020 	write_c0_gtoffset(0);
1021 }
1022 
1023 static inline void cpu_probe_vz(struct cpuinfo_mips *c)
1024 {
1025 	cpu_probe_guestctl0(c);
1026 	if (cpu_has_guestctl1)
1027 		cpu_probe_guestctl1(c);
1028 
1029 	cpu_probe_gtoffset(c);
1030 
1031 	decode_guest_configs(c);
1032 }
1033 
1034 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
1035 		| MIPS_CPU_COUNTER)
1036 
1037 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
1038 {
1039 	switch (c->processor_id & PRID_IMP_MASK) {
1040 	case PRID_IMP_R2000:
1041 		c->cputype = CPU_R2000;
1042 		__cpu_name[cpu] = "R2000";
1043 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1044 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1045 			     MIPS_CPU_NOFPUEX;
1046 		if (__cpu_has_fpu())
1047 			c->options |= MIPS_CPU_FPU;
1048 		c->tlbsize = 64;
1049 		break;
1050 	case PRID_IMP_R3000:
1051 		if ((c->processor_id & PRID_REV_MASK) == PRID_REV_R3000A) {
1052 			if (cpu_has_confreg()) {
1053 				c->cputype = CPU_R3081E;
1054 				__cpu_name[cpu] = "R3081";
1055 			} else {
1056 				c->cputype = CPU_R3000A;
1057 				__cpu_name[cpu] = "R3000A";
1058 			}
1059 		} else {
1060 			c->cputype = CPU_R3000;
1061 			__cpu_name[cpu] = "R3000";
1062 		}
1063 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1064 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1065 			     MIPS_CPU_NOFPUEX;
1066 		if (__cpu_has_fpu())
1067 			c->options |= MIPS_CPU_FPU;
1068 		c->tlbsize = 64;
1069 		break;
1070 	case PRID_IMP_R4000:
1071 		if (read_c0_config() & CONF_SC) {
1072 			if ((c->processor_id & PRID_REV_MASK) >=
1073 			    PRID_REV_R4400) {
1074 				c->cputype = CPU_R4400PC;
1075 				__cpu_name[cpu] = "R4400PC";
1076 			} else {
1077 				c->cputype = CPU_R4000PC;
1078 				__cpu_name[cpu] = "R4000PC";
1079 			}
1080 		} else {
1081 			int cca = read_c0_config() & CONF_CM_CMASK;
1082 			int mc;
1083 
1084 			/*
1085 			 * SC and MC versions can't be reliably told apart,
1086 			 * but only the latter support coherent caching
1087 			 * modes so assume the firmware has set the KSEG0
1088 			 * coherency attribute reasonably (if uncached, we
1089 			 * assume SC).
1090 			 */
1091 			switch (cca) {
1092 			case CONF_CM_CACHABLE_CE:
1093 			case CONF_CM_CACHABLE_COW:
1094 			case CONF_CM_CACHABLE_CUW:
1095 				mc = 1;
1096 				break;
1097 			default:
1098 				mc = 0;
1099 				break;
1100 			}
1101 			if ((c->processor_id & PRID_REV_MASK) >=
1102 			    PRID_REV_R4400) {
1103 				c->cputype = mc ? CPU_R4400MC : CPU_R4400SC;
1104 				__cpu_name[cpu] = mc ? "R4400MC" : "R4400SC";
1105 			} else {
1106 				c->cputype = mc ? CPU_R4000MC : CPU_R4000SC;
1107 				__cpu_name[cpu] = mc ? "R4000MC" : "R4000SC";
1108 			}
1109 		}
1110 
1111 		set_isa(c, MIPS_CPU_ISA_III);
1112 		c->fpu_msk31 |= FPU_CSR_CONDX;
1113 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1114 			     MIPS_CPU_WATCH | MIPS_CPU_VCE |
1115 			     MIPS_CPU_LLSC;
1116 		c->tlbsize = 48;
1117 		break;
1118 	case PRID_IMP_VR41XX:
1119 		set_isa(c, MIPS_CPU_ISA_III);
1120 		c->fpu_msk31 |= FPU_CSR_CONDX;
1121 		c->options = R4K_OPTS;
1122 		c->tlbsize = 32;
1123 		switch (c->processor_id & 0xf0) {
1124 		case PRID_REV_VR4111:
1125 			c->cputype = CPU_VR4111;
1126 			__cpu_name[cpu] = "NEC VR4111";
1127 			break;
1128 		case PRID_REV_VR4121:
1129 			c->cputype = CPU_VR4121;
1130 			__cpu_name[cpu] = "NEC VR4121";
1131 			break;
1132 		case PRID_REV_VR4122:
1133 			if ((c->processor_id & 0xf) < 0x3) {
1134 				c->cputype = CPU_VR4122;
1135 				__cpu_name[cpu] = "NEC VR4122";
1136 			} else {
1137 				c->cputype = CPU_VR4181A;
1138 				__cpu_name[cpu] = "NEC VR4181A";
1139 			}
1140 			break;
1141 		case PRID_REV_VR4130:
1142 			if ((c->processor_id & 0xf) < 0x4) {
1143 				c->cputype = CPU_VR4131;
1144 				__cpu_name[cpu] = "NEC VR4131";
1145 			} else {
1146 				c->cputype = CPU_VR4133;
1147 				c->options |= MIPS_CPU_LLSC;
1148 				__cpu_name[cpu] = "NEC VR4133";
1149 			}
1150 			break;
1151 		default:
1152 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
1153 			c->cputype = CPU_VR41XX;
1154 			__cpu_name[cpu] = "NEC Vr41xx";
1155 			break;
1156 		}
1157 		break;
1158 	case PRID_IMP_R4300:
1159 		c->cputype = CPU_R4300;
1160 		__cpu_name[cpu] = "R4300";
1161 		set_isa(c, MIPS_CPU_ISA_III);
1162 		c->fpu_msk31 |= FPU_CSR_CONDX;
1163 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1164 			     MIPS_CPU_LLSC;
1165 		c->tlbsize = 32;
1166 		break;
1167 	case PRID_IMP_R4600:
1168 		c->cputype = CPU_R4600;
1169 		__cpu_name[cpu] = "R4600";
1170 		set_isa(c, MIPS_CPU_ISA_III);
1171 		c->fpu_msk31 |= FPU_CSR_CONDX;
1172 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1173 			     MIPS_CPU_LLSC;
1174 		c->tlbsize = 48;
1175 		break;
1176 	#if 0
1177 	case PRID_IMP_R4650:
1178 		/*
1179 		 * This processor doesn't have an MMU, so it's not
1180 		 * "real easy" to run Linux on it. It is left purely
1181 		 * for documentation.  Commented out because it shares
1182 		 * it's c0_prid id number with the TX3900.
1183 		 */
1184 		c->cputype = CPU_R4650;
1185 		__cpu_name[cpu] = "R4650";
1186 		set_isa(c, MIPS_CPU_ISA_III);
1187 		c->fpu_msk31 |= FPU_CSR_CONDX;
1188 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
1189 		c->tlbsize = 48;
1190 		break;
1191 	#endif
1192 	case PRID_IMP_R4700:
1193 		c->cputype = CPU_R4700;
1194 		__cpu_name[cpu] = "R4700";
1195 		set_isa(c, MIPS_CPU_ISA_III);
1196 		c->fpu_msk31 |= FPU_CSR_CONDX;
1197 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1198 			     MIPS_CPU_LLSC;
1199 		c->tlbsize = 48;
1200 		break;
1201 	case PRID_IMP_TX49:
1202 		c->cputype = CPU_TX49XX;
1203 		__cpu_name[cpu] = "R49XX";
1204 		set_isa(c, MIPS_CPU_ISA_III);
1205 		c->fpu_msk31 |= FPU_CSR_CONDX;
1206 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
1207 		if (!(c->processor_id & 0x08))
1208 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
1209 		c->tlbsize = 48;
1210 		break;
1211 	case PRID_IMP_R5000:
1212 		c->cputype = CPU_R5000;
1213 		__cpu_name[cpu] = "R5000";
1214 		set_isa(c, MIPS_CPU_ISA_IV);
1215 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1216 			     MIPS_CPU_LLSC;
1217 		c->tlbsize = 48;
1218 		break;
1219 	case PRID_IMP_R5500:
1220 		c->cputype = CPU_R5500;
1221 		__cpu_name[cpu] = "R5500";
1222 		set_isa(c, MIPS_CPU_ISA_IV);
1223 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1224 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1225 		c->tlbsize = 48;
1226 		break;
1227 	case PRID_IMP_NEVADA:
1228 		c->cputype = CPU_NEVADA;
1229 		__cpu_name[cpu] = "Nevada";
1230 		set_isa(c, MIPS_CPU_ISA_IV);
1231 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1232 			     MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
1233 		c->tlbsize = 48;
1234 		break;
1235 	case PRID_IMP_RM7000:
1236 		c->cputype = CPU_RM7000;
1237 		__cpu_name[cpu] = "RM7000";
1238 		set_isa(c, MIPS_CPU_ISA_IV);
1239 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1240 			     MIPS_CPU_LLSC;
1241 		/*
1242 		 * Undocumented RM7000:	 Bit 29 in the info register of
1243 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
1244 		 * entries.
1245 		 *
1246 		 * 29	   1 =>	   64 entry JTLB
1247 		 *	   0 =>	   48 entry JTLB
1248 		 */
1249 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
1250 		break;
1251 	case PRID_IMP_R10000:
1252 		c->cputype = CPU_R10000;
1253 		__cpu_name[cpu] = "R10000";
1254 		set_isa(c, MIPS_CPU_ISA_IV);
1255 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1256 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1257 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1258 			     MIPS_CPU_LLSC;
1259 		c->tlbsize = 64;
1260 		break;
1261 	case PRID_IMP_R12000:
1262 		c->cputype = CPU_R12000;
1263 		__cpu_name[cpu] = "R12000";
1264 		set_isa(c, MIPS_CPU_ISA_IV);
1265 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1266 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1267 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1268 			     MIPS_CPU_LLSC;
1269 		c->tlbsize = 64;
1270 		write_c0_r10k_diag(read_c0_r10k_diag() | R10K_DIAG_E_GHIST);
1271 		break;
1272 	case PRID_IMP_R14000:
1273 		if (((c->processor_id >> 4) & 0x0f) > 2) {
1274 			c->cputype = CPU_R16000;
1275 			__cpu_name[cpu] = "R16000";
1276 		} else {
1277 			c->cputype = CPU_R14000;
1278 			__cpu_name[cpu] = "R14000";
1279 		}
1280 		set_isa(c, MIPS_CPU_ISA_IV);
1281 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1282 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1283 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1284 			     MIPS_CPU_LLSC;
1285 		c->tlbsize = 64;
1286 		write_c0_r10k_diag(read_c0_r10k_diag() | R10K_DIAG_E_GHIST);
1287 		break;
1288 	case PRID_IMP_LOONGSON_64C:  /* Loongson-2/3 */
1289 		switch (c->processor_id & PRID_REV_MASK) {
1290 		case PRID_REV_LOONGSON2E:
1291 			c->cputype = CPU_LOONGSON2EF;
1292 			__cpu_name[cpu] = "ICT Loongson-2";
1293 			set_elf_platform(cpu, "loongson2e");
1294 			set_isa(c, MIPS_CPU_ISA_III);
1295 			c->fpu_msk31 |= FPU_CSR_CONDX;
1296 			break;
1297 		case PRID_REV_LOONGSON2F:
1298 			c->cputype = CPU_LOONGSON2EF;
1299 			__cpu_name[cpu] = "ICT Loongson-2";
1300 			set_elf_platform(cpu, "loongson2f");
1301 			set_isa(c, MIPS_CPU_ISA_III);
1302 			c->fpu_msk31 |= FPU_CSR_CONDX;
1303 			break;
1304 		case PRID_REV_LOONGSON3A_R1:
1305 			c->cputype = CPU_LOONGSON64;
1306 			__cpu_name[cpu] = "ICT Loongson-3";
1307 			set_elf_platform(cpu, "loongson3a");
1308 			set_isa(c, MIPS_CPU_ISA_M64R1);
1309 			c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
1310 				MIPS_ASE_LOONGSON_EXT);
1311 			break;
1312 		case PRID_REV_LOONGSON3B_R1:
1313 		case PRID_REV_LOONGSON3B_R2:
1314 			c->cputype = CPU_LOONGSON64;
1315 			__cpu_name[cpu] = "ICT Loongson-3";
1316 			set_elf_platform(cpu, "loongson3b");
1317 			set_isa(c, MIPS_CPU_ISA_M64R1);
1318 			c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
1319 				MIPS_ASE_LOONGSON_EXT);
1320 			break;
1321 		}
1322 
1323 		c->options = R4K_OPTS |
1324 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
1325 			     MIPS_CPU_32FPR;
1326 		c->tlbsize = 64;
1327 		set_cpu_asid_mask(c, MIPS_ENTRYHI_ASID);
1328 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1329 		break;
1330 	case PRID_IMP_LOONGSON_32:  /* Loongson-1 */
1331 		decode_configs(c);
1332 
1333 		c->cputype = CPU_LOONGSON32;
1334 
1335 		switch (c->processor_id & PRID_REV_MASK) {
1336 		case PRID_REV_LOONGSON1B:
1337 			__cpu_name[cpu] = "Loongson 1B";
1338 			break;
1339 		}
1340 
1341 		break;
1342 	}
1343 }
1344 
1345 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
1346 {
1347 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1348 	switch (c->processor_id & PRID_IMP_MASK) {
1349 	case PRID_IMP_QEMU_GENERIC:
1350 		c->writecombine = _CACHE_UNCACHED;
1351 		c->cputype = CPU_QEMU_GENERIC;
1352 		__cpu_name[cpu] = "MIPS GENERIC QEMU";
1353 		break;
1354 	case PRID_IMP_4KC:
1355 		c->cputype = CPU_4KC;
1356 		c->writecombine = _CACHE_UNCACHED;
1357 		__cpu_name[cpu] = "MIPS 4Kc";
1358 		break;
1359 	case PRID_IMP_4KEC:
1360 	case PRID_IMP_4KECR2:
1361 		c->cputype = CPU_4KEC;
1362 		c->writecombine = _CACHE_UNCACHED;
1363 		__cpu_name[cpu] = "MIPS 4KEc";
1364 		break;
1365 	case PRID_IMP_4KSC:
1366 	case PRID_IMP_4KSD:
1367 		c->cputype = CPU_4KSC;
1368 		c->writecombine = _CACHE_UNCACHED;
1369 		__cpu_name[cpu] = "MIPS 4KSc";
1370 		break;
1371 	case PRID_IMP_5KC:
1372 		c->cputype = CPU_5KC;
1373 		c->writecombine = _CACHE_UNCACHED;
1374 		__cpu_name[cpu] = "MIPS 5Kc";
1375 		break;
1376 	case PRID_IMP_5KE:
1377 		c->cputype = CPU_5KE;
1378 		c->writecombine = _CACHE_UNCACHED;
1379 		__cpu_name[cpu] = "MIPS 5KE";
1380 		break;
1381 	case PRID_IMP_20KC:
1382 		c->cputype = CPU_20KC;
1383 		c->writecombine = _CACHE_UNCACHED;
1384 		__cpu_name[cpu] = "MIPS 20Kc";
1385 		break;
1386 	case PRID_IMP_24K:
1387 		c->cputype = CPU_24K;
1388 		c->writecombine = _CACHE_UNCACHED;
1389 		__cpu_name[cpu] = "MIPS 24Kc";
1390 		break;
1391 	case PRID_IMP_24KE:
1392 		c->cputype = CPU_24K;
1393 		c->writecombine = _CACHE_UNCACHED;
1394 		__cpu_name[cpu] = "MIPS 24KEc";
1395 		break;
1396 	case PRID_IMP_25KF:
1397 		c->cputype = CPU_25KF;
1398 		c->writecombine = _CACHE_UNCACHED;
1399 		__cpu_name[cpu] = "MIPS 25Kc";
1400 		break;
1401 	case PRID_IMP_34K:
1402 		c->cputype = CPU_34K;
1403 		c->writecombine = _CACHE_UNCACHED;
1404 		__cpu_name[cpu] = "MIPS 34Kc";
1405 		cpu_set_mt_per_tc_perf(c);
1406 		break;
1407 	case PRID_IMP_74K:
1408 		c->cputype = CPU_74K;
1409 		c->writecombine = _CACHE_UNCACHED;
1410 		__cpu_name[cpu] = "MIPS 74Kc";
1411 		break;
1412 	case PRID_IMP_M14KC:
1413 		c->cputype = CPU_M14KC;
1414 		c->writecombine = _CACHE_UNCACHED;
1415 		__cpu_name[cpu] = "MIPS M14Kc";
1416 		break;
1417 	case PRID_IMP_M14KEC:
1418 		c->cputype = CPU_M14KEC;
1419 		c->writecombine = _CACHE_UNCACHED;
1420 		__cpu_name[cpu] = "MIPS M14KEc";
1421 		break;
1422 	case PRID_IMP_1004K:
1423 		c->cputype = CPU_1004K;
1424 		c->writecombine = _CACHE_UNCACHED;
1425 		__cpu_name[cpu] = "MIPS 1004Kc";
1426 		cpu_set_mt_per_tc_perf(c);
1427 		break;
1428 	case PRID_IMP_1074K:
1429 		c->cputype = CPU_1074K;
1430 		c->writecombine = _CACHE_UNCACHED;
1431 		__cpu_name[cpu] = "MIPS 1074Kc";
1432 		break;
1433 	case PRID_IMP_INTERAPTIV_UP:
1434 		c->cputype = CPU_INTERAPTIV;
1435 		__cpu_name[cpu] = "MIPS interAptiv";
1436 		cpu_set_mt_per_tc_perf(c);
1437 		break;
1438 	case PRID_IMP_INTERAPTIV_MP:
1439 		c->cputype = CPU_INTERAPTIV;
1440 		__cpu_name[cpu] = "MIPS interAptiv (multi)";
1441 		cpu_set_mt_per_tc_perf(c);
1442 		break;
1443 	case PRID_IMP_PROAPTIV_UP:
1444 		c->cputype = CPU_PROAPTIV;
1445 		__cpu_name[cpu] = "MIPS proAptiv";
1446 		break;
1447 	case PRID_IMP_PROAPTIV_MP:
1448 		c->cputype = CPU_PROAPTIV;
1449 		__cpu_name[cpu] = "MIPS proAptiv (multi)";
1450 		break;
1451 	case PRID_IMP_P5600:
1452 		c->cputype = CPU_P5600;
1453 		__cpu_name[cpu] = "MIPS P5600";
1454 		break;
1455 	case PRID_IMP_P6600:
1456 		c->cputype = CPU_P6600;
1457 		__cpu_name[cpu] = "MIPS P6600";
1458 		break;
1459 	case PRID_IMP_I6400:
1460 		c->cputype = CPU_I6400;
1461 		__cpu_name[cpu] = "MIPS I6400";
1462 		break;
1463 	case PRID_IMP_I6500:
1464 		c->cputype = CPU_I6500;
1465 		__cpu_name[cpu] = "MIPS I6500";
1466 		break;
1467 	case PRID_IMP_M5150:
1468 		c->cputype = CPU_M5150;
1469 		__cpu_name[cpu] = "MIPS M5150";
1470 		break;
1471 	case PRID_IMP_M6250:
1472 		c->cputype = CPU_M6250;
1473 		__cpu_name[cpu] = "MIPS M6250";
1474 		break;
1475 	}
1476 
1477 	decode_configs(c);
1478 
1479 	spram_config();
1480 
1481 	mm_config(c);
1482 
1483 	switch (__get_cpu_type(c->cputype)) {
1484 	case CPU_M5150:
1485 	case CPU_P5600:
1486 		set_isa(c, MIPS_CPU_ISA_M32R5);
1487 		break;
1488 	case CPU_I6500:
1489 		c->options |= MIPS_CPU_SHARED_FTLB_ENTRIES;
1490 		fallthrough;
1491 	case CPU_I6400:
1492 		c->options |= MIPS_CPU_SHARED_FTLB_RAM;
1493 		fallthrough;
1494 	default:
1495 		break;
1496 	}
1497 
1498 	/* Recent MIPS cores use the implementation-dependent ExcCode 16 for
1499 	 * cache/FTLB parity exceptions.
1500 	 */
1501 	switch (__get_cpu_type(c->cputype)) {
1502 	case CPU_PROAPTIV:
1503 	case CPU_P5600:
1504 	case CPU_P6600:
1505 	case CPU_I6400:
1506 	case CPU_I6500:
1507 		c->options |= MIPS_CPU_FTLBPAREX;
1508 		break;
1509 	}
1510 }
1511 
1512 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
1513 {
1514 	decode_configs(c);
1515 	switch (c->processor_id & PRID_IMP_MASK) {
1516 	case PRID_IMP_AU1_REV1:
1517 	case PRID_IMP_AU1_REV2:
1518 		c->cputype = CPU_ALCHEMY;
1519 		switch ((c->processor_id >> 24) & 0xff) {
1520 		case 0:
1521 			__cpu_name[cpu] = "Au1000";
1522 			break;
1523 		case 1:
1524 			__cpu_name[cpu] = "Au1500";
1525 			break;
1526 		case 2:
1527 			__cpu_name[cpu] = "Au1100";
1528 			break;
1529 		case 3:
1530 			__cpu_name[cpu] = "Au1550";
1531 			break;
1532 		case 4:
1533 			__cpu_name[cpu] = "Au1200";
1534 			if ((c->processor_id & PRID_REV_MASK) == 2)
1535 				__cpu_name[cpu] = "Au1250";
1536 			break;
1537 		case 5:
1538 			__cpu_name[cpu] = "Au1210";
1539 			break;
1540 		default:
1541 			__cpu_name[cpu] = "Au1xxx";
1542 			break;
1543 		}
1544 		break;
1545 	}
1546 }
1547 
1548 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
1549 {
1550 	decode_configs(c);
1551 
1552 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1553 	switch (c->processor_id & PRID_IMP_MASK) {
1554 	case PRID_IMP_SB1:
1555 		c->cputype = CPU_SB1;
1556 		__cpu_name[cpu] = "SiByte SB1";
1557 		/* FPU in pass1 is known to have issues. */
1558 		if ((c->processor_id & PRID_REV_MASK) < 0x02)
1559 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
1560 		break;
1561 	case PRID_IMP_SB1A:
1562 		c->cputype = CPU_SB1A;
1563 		__cpu_name[cpu] = "SiByte SB1A";
1564 		break;
1565 	}
1566 }
1567 
1568 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
1569 {
1570 	decode_configs(c);
1571 	switch (c->processor_id & PRID_IMP_MASK) {
1572 	case PRID_IMP_SR71000:
1573 		c->cputype = CPU_SR71000;
1574 		__cpu_name[cpu] = "Sandcraft SR71000";
1575 		c->scache.ways = 8;
1576 		c->tlbsize = 64;
1577 		break;
1578 	}
1579 }
1580 
1581 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
1582 {
1583 	decode_configs(c);
1584 	switch (c->processor_id & PRID_IMP_MASK) {
1585 	case PRID_IMP_PR4450:
1586 		c->cputype = CPU_PR4450;
1587 		__cpu_name[cpu] = "Philips PR4450";
1588 		set_isa(c, MIPS_CPU_ISA_M32R1);
1589 		break;
1590 	}
1591 }
1592 
1593 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
1594 {
1595 	decode_configs(c);
1596 	switch (c->processor_id & PRID_IMP_MASK) {
1597 	case PRID_IMP_BMIPS32_REV4:
1598 	case PRID_IMP_BMIPS32_REV8:
1599 		c->cputype = CPU_BMIPS32;
1600 		__cpu_name[cpu] = "Broadcom BMIPS32";
1601 		set_elf_platform(cpu, "bmips32");
1602 		break;
1603 	case PRID_IMP_BMIPS3300:
1604 	case PRID_IMP_BMIPS3300_ALT:
1605 	case PRID_IMP_BMIPS3300_BUG:
1606 		c->cputype = CPU_BMIPS3300;
1607 		__cpu_name[cpu] = "Broadcom BMIPS3300";
1608 		set_elf_platform(cpu, "bmips3300");
1609 		reserve_exception_space(0x400, VECTORSPACING * 64);
1610 		break;
1611 	case PRID_IMP_BMIPS43XX: {
1612 		int rev = c->processor_id & PRID_REV_MASK;
1613 
1614 		if (rev >= PRID_REV_BMIPS4380_LO &&
1615 				rev <= PRID_REV_BMIPS4380_HI) {
1616 			c->cputype = CPU_BMIPS4380;
1617 			__cpu_name[cpu] = "Broadcom BMIPS4380";
1618 			set_elf_platform(cpu, "bmips4380");
1619 			c->options |= MIPS_CPU_RIXI;
1620 			reserve_exception_space(0x400, VECTORSPACING * 64);
1621 		} else {
1622 			c->cputype = CPU_BMIPS4350;
1623 			__cpu_name[cpu] = "Broadcom BMIPS4350";
1624 			set_elf_platform(cpu, "bmips4350");
1625 		}
1626 		break;
1627 	}
1628 	case PRID_IMP_BMIPS5000:
1629 	case PRID_IMP_BMIPS5200:
1630 		c->cputype = CPU_BMIPS5000;
1631 		if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_BMIPS5200)
1632 			__cpu_name[cpu] = "Broadcom BMIPS5200";
1633 		else
1634 			__cpu_name[cpu] = "Broadcom BMIPS5000";
1635 		set_elf_platform(cpu, "bmips5000");
1636 		c->options |= MIPS_CPU_ULRI | MIPS_CPU_RIXI;
1637 		reserve_exception_space(0x1000, VECTORSPACING * 64);
1638 		break;
1639 	}
1640 }
1641 
1642 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
1643 {
1644 	decode_configs(c);
1645 	switch (c->processor_id & PRID_IMP_MASK) {
1646 	case PRID_IMP_CAVIUM_CN38XX:
1647 	case PRID_IMP_CAVIUM_CN31XX:
1648 	case PRID_IMP_CAVIUM_CN30XX:
1649 		c->cputype = CPU_CAVIUM_OCTEON;
1650 		__cpu_name[cpu] = "Cavium Octeon";
1651 		goto platform;
1652 	case PRID_IMP_CAVIUM_CN58XX:
1653 	case PRID_IMP_CAVIUM_CN56XX:
1654 	case PRID_IMP_CAVIUM_CN50XX:
1655 	case PRID_IMP_CAVIUM_CN52XX:
1656 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
1657 		__cpu_name[cpu] = "Cavium Octeon+";
1658 platform:
1659 		set_elf_platform(cpu, "octeon");
1660 		break;
1661 	case PRID_IMP_CAVIUM_CN61XX:
1662 	case PRID_IMP_CAVIUM_CN63XX:
1663 	case PRID_IMP_CAVIUM_CN66XX:
1664 	case PRID_IMP_CAVIUM_CN68XX:
1665 	case PRID_IMP_CAVIUM_CNF71XX:
1666 		c->cputype = CPU_CAVIUM_OCTEON2;
1667 		__cpu_name[cpu] = "Cavium Octeon II";
1668 		set_elf_platform(cpu, "octeon2");
1669 		break;
1670 	case PRID_IMP_CAVIUM_CN70XX:
1671 	case PRID_IMP_CAVIUM_CN73XX:
1672 	case PRID_IMP_CAVIUM_CNF75XX:
1673 	case PRID_IMP_CAVIUM_CN78XX:
1674 		c->cputype = CPU_CAVIUM_OCTEON3;
1675 		__cpu_name[cpu] = "Cavium Octeon III";
1676 		set_elf_platform(cpu, "octeon3");
1677 		break;
1678 	default:
1679 		printk(KERN_INFO "Unknown Octeon chip!\n");
1680 		c->cputype = CPU_UNKNOWN;
1681 		break;
1682 	}
1683 }
1684 
1685 #ifdef CONFIG_CPU_LOONGSON64
1686 #include <loongson_regs.h>
1687 
1688 static inline void decode_cpucfg(struct cpuinfo_mips *c)
1689 {
1690 	u32 cfg1 = read_cpucfg(LOONGSON_CFG1);
1691 	u32 cfg2 = read_cpucfg(LOONGSON_CFG2);
1692 	u32 cfg3 = read_cpucfg(LOONGSON_CFG3);
1693 
1694 	if (cfg1 & LOONGSON_CFG1_MMI)
1695 		c->ases |= MIPS_ASE_LOONGSON_MMI;
1696 
1697 	if (cfg2 & LOONGSON_CFG2_LEXT1)
1698 		c->ases |= MIPS_ASE_LOONGSON_EXT;
1699 
1700 	if (cfg2 & LOONGSON_CFG2_LEXT2)
1701 		c->ases |= MIPS_ASE_LOONGSON_EXT2;
1702 
1703 	if (cfg2 & LOONGSON_CFG2_LSPW) {
1704 		c->options |= MIPS_CPU_LDPTE;
1705 		c->guest.options |= MIPS_CPU_LDPTE;
1706 	}
1707 
1708 	if (cfg3 & LOONGSON_CFG3_LCAMP)
1709 		c->ases |= MIPS_ASE_LOONGSON_CAM;
1710 }
1711 
1712 static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
1713 {
1714 	/* All Loongson processors covered here define ExcCode 16 as GSExc. */
1715 	c->options |= MIPS_CPU_GSEXCEX;
1716 
1717 	switch (c->processor_id & PRID_IMP_MASK) {
1718 	case PRID_IMP_LOONGSON_64R: /* Loongson-64 Reduced */
1719 		switch (c->processor_id & PRID_REV_MASK) {
1720 		case PRID_REV_LOONGSON2K_R1_0:
1721 		case PRID_REV_LOONGSON2K_R1_1:
1722 		case PRID_REV_LOONGSON2K_R1_2:
1723 		case PRID_REV_LOONGSON2K_R1_3:
1724 			c->cputype = CPU_LOONGSON64;
1725 			__cpu_name[cpu] = "Loongson-2K";
1726 			set_elf_platform(cpu, "gs264e");
1727 			set_isa(c, MIPS_CPU_ISA_M64R2);
1728 			break;
1729 		}
1730 		c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_EXT |
1731 				MIPS_ASE_LOONGSON_EXT2);
1732 		break;
1733 	case PRID_IMP_LOONGSON_64C:  /* Loongson-3 Classic */
1734 		switch (c->processor_id & PRID_REV_MASK) {
1735 		case PRID_REV_LOONGSON3A_R2_0:
1736 		case PRID_REV_LOONGSON3A_R2_1:
1737 			c->cputype = CPU_LOONGSON64;
1738 			__cpu_name[cpu] = "ICT Loongson-3";
1739 			set_elf_platform(cpu, "loongson3a");
1740 			set_isa(c, MIPS_CPU_ISA_M64R2);
1741 			break;
1742 		case PRID_REV_LOONGSON3A_R3_0:
1743 		case PRID_REV_LOONGSON3A_R3_1:
1744 			c->cputype = CPU_LOONGSON64;
1745 			__cpu_name[cpu] = "ICT Loongson-3";
1746 			set_elf_platform(cpu, "loongson3a");
1747 			set_isa(c, MIPS_CPU_ISA_M64R2);
1748 			break;
1749 		}
1750 		/*
1751 		 * Loongson-3 Classic did not implement MIPS standard TLBINV
1752 		 * but implemented TLBINVF and EHINV. As currently we're only
1753 		 * using these two features, enable MIPS_CPU_TLBINV as well.
1754 		 *
1755 		 * Also some early Loongson-3A2000 had wrong TLB type in Config
1756 		 * register, we correct it here.
1757 		 */
1758 		c->options |= MIPS_CPU_FTLB | MIPS_CPU_TLBINV | MIPS_CPU_LDPTE;
1759 		c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
1760 			MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
1761 		c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
1762 		break;
1763 	case PRID_IMP_LOONGSON_64G:
1764 		c->cputype = CPU_LOONGSON64;
1765 		__cpu_name[cpu] = "ICT Loongson-3";
1766 		set_elf_platform(cpu, "loongson3a");
1767 		set_isa(c, MIPS_CPU_ISA_M64R2);
1768 		decode_cpucfg(c);
1769 		break;
1770 	default:
1771 		panic("Unknown Loongson Processor ID!");
1772 		break;
1773 	}
1774 
1775 	decode_configs(c);
1776 }
1777 #else
1778 static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) { }
1779 #endif
1780 
1781 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
1782 {
1783 	decode_configs(c);
1784 
1785 	/*
1786 	 * XBurst misses a config2 register, so config3 decode was skipped in
1787 	 * decode_configs().
1788 	 */
1789 	decode_config3(c);
1790 
1791 	/* XBurst does not implement the CP0 counter. */
1792 	c->options &= ~MIPS_CPU_COUNTER;
1793 	BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);
1794 
1795 	/* XBurst has virtually tagged icache */
1796 	c->icache.flags |= MIPS_CACHE_VTAG;
1797 
1798 	switch (c->processor_id & PRID_IMP_MASK) {
1799 
1800 	/* XBurst®1 with MXU1.0/MXU1.1 SIMD ISA */
1801 	case PRID_IMP_XBURST_REV1:
1802 
1803 		/*
1804 		 * The XBurst core by default attempts to avoid branch target
1805 		 * buffer lookups by detecting & special casing loops. This
1806 		 * feature will cause BogoMIPS and lpj calculate in error.
1807 		 * Set cp0 config7 bit 4 to disable this feature.
1808 		 */
1809 		set_c0_config7(MIPS_CONF7_BTB_LOOP_EN);
1810 
1811 		switch (c->processor_id & PRID_COMP_MASK) {
1812 
1813 		/*
1814 		 * The config0 register in the XBurst CPUs with a processor ID of
1815 		 * PRID_COMP_INGENIC_D0 report themselves as MIPS32r2 compatible,
1816 		 * but they don't actually support this ISA.
1817 		 */
1818 		case PRID_COMP_INGENIC_D0:
1819 			c->isa_level &= ~MIPS_CPU_ISA_M32R2;
1820 
1821 			/* FPU is not properly detected on JZ4760(B). */
1822 			if (c->processor_id == 0x2ed0024f)
1823 				c->options |= MIPS_CPU_FPU;
1824 
1825 			fallthrough;
1826 
1827 		/*
1828 		 * The config0 register in the XBurst CPUs with a processor ID of
1829 		 * PRID_COMP_INGENIC_D0 or PRID_COMP_INGENIC_D1 has an abandoned
1830 		 * huge page tlb mode, this mode is not compatible with the MIPS
1831 		 * standard, it will cause tlbmiss and into an infinite loop
1832 		 * (line 21 in the tlb-funcs.S) when starting the init process.
1833 		 * After chip reset, the default is HPTLB mode, Write 0xa9000000
1834 		 * to cp0 register 5 sel 4 to switch back to VTLB mode to prevent
1835 		 * getting stuck.
1836 		 */
1837 		case PRID_COMP_INGENIC_D1:
1838 			write_c0_page_ctrl(XBURST_PAGECTRL_HPTLB_DIS);
1839 			break;
1840 
1841 		default:
1842 			break;
1843 		}
1844 		fallthrough;
1845 
1846 	/* XBurst®1 with MXU2.0 SIMD ISA */
1847 	case PRID_IMP_XBURST_REV2:
1848 		/* Ingenic uses the WA bit to achieve write-combine memory writes */
1849 		c->writecombine = _CACHE_CACHABLE_WA;
1850 		c->cputype = CPU_XBURST;
1851 		__cpu_name[cpu] = "Ingenic XBurst";
1852 		break;
1853 
1854 	/* XBurst®2 with MXU2.1 SIMD ISA */
1855 	case PRID_IMP_XBURST2:
1856 		c->cputype = CPU_XBURST;
1857 		__cpu_name[cpu] = "Ingenic XBurst II";
1858 		break;
1859 
1860 	default:
1861 		panic("Unknown Ingenic Processor ID!");
1862 		break;
1863 	}
1864 }
1865 
1866 #ifdef CONFIG_64BIT
1867 /* For use by uaccess.h */
1868 u64 __ua_limit;
1869 EXPORT_SYMBOL(__ua_limit);
1870 #endif
1871 
1872 const char *__cpu_name[NR_CPUS];
1873 const char *__elf_platform;
1874 const char *__elf_base_platform;
1875 
1876 void cpu_probe(void)
1877 {
1878 	struct cpuinfo_mips *c = &current_cpu_data;
1879 	unsigned int cpu = smp_processor_id();
1880 
1881 	/*
1882 	 * Set a default elf platform, cpu probe may later
1883 	 * overwrite it with a more precise value
1884 	 */
1885 	set_elf_platform(cpu, "mips");
1886 
1887 	c->processor_id = PRID_IMP_UNKNOWN;
1888 	c->fpu_id	= FPIR_IMP_NONE;
1889 	c->cputype	= CPU_UNKNOWN;
1890 	c->writecombine = _CACHE_UNCACHED;
1891 
1892 	c->fpu_csr31	= FPU_CSR_RN;
1893 	c->fpu_msk31	= FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
1894 
1895 	c->processor_id = read_c0_prid();
1896 	switch (c->processor_id & PRID_COMP_MASK) {
1897 	case PRID_COMP_LEGACY:
1898 		cpu_probe_legacy(c, cpu);
1899 		break;
1900 	case PRID_COMP_MIPS:
1901 		cpu_probe_mips(c, cpu);
1902 		break;
1903 	case PRID_COMP_ALCHEMY:
1904 		cpu_probe_alchemy(c, cpu);
1905 		break;
1906 	case PRID_COMP_SIBYTE:
1907 		cpu_probe_sibyte(c, cpu);
1908 		break;
1909 	case PRID_COMP_BROADCOM:
1910 		cpu_probe_broadcom(c, cpu);
1911 		break;
1912 	case PRID_COMP_SANDCRAFT:
1913 		cpu_probe_sandcraft(c, cpu);
1914 		break;
1915 	case PRID_COMP_NXP:
1916 		cpu_probe_nxp(c, cpu);
1917 		break;
1918 	case PRID_COMP_CAVIUM:
1919 		cpu_probe_cavium(c, cpu);
1920 		break;
1921 	case PRID_COMP_LOONGSON:
1922 		cpu_probe_loongson(c, cpu);
1923 		break;
1924 	case PRID_COMP_INGENIC_13:
1925 	case PRID_COMP_INGENIC_D0:
1926 	case PRID_COMP_INGENIC_D1:
1927 	case PRID_COMP_INGENIC_E1:
1928 		cpu_probe_ingenic(c, cpu);
1929 		break;
1930 	}
1931 
1932 	BUG_ON(!__cpu_name[cpu]);
1933 	BUG_ON(c->cputype == CPU_UNKNOWN);
1934 
1935 	/*
1936 	 * Platform code can force the cpu type to optimize code
1937 	 * generation. In that case be sure the cpu type is correctly
1938 	 * manually setup otherwise it could trigger some nasty bugs.
1939 	 */
1940 	BUG_ON(current_cpu_type() != c->cputype);
1941 
1942 	if (cpu_has_rixi) {
1943 		/* Enable the RIXI exceptions */
1944 		set_c0_pagegrain(PG_IEC);
1945 		back_to_back_c0_hazard();
1946 		/* Verify the IEC bit is set */
1947 		if (read_c0_pagegrain() & PG_IEC)
1948 			c->options |= MIPS_CPU_RIXIEX;
1949 	}
1950 
1951 	if (mips_fpu_disabled)
1952 		c->options &= ~MIPS_CPU_FPU;
1953 
1954 	if (mips_dsp_disabled)
1955 		c->ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
1956 
1957 	if (mips_htw_disabled) {
1958 		c->options &= ~MIPS_CPU_HTW;
1959 		write_c0_pwctl(read_c0_pwctl() &
1960 			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
1961 	}
1962 
1963 	if (c->options & MIPS_CPU_FPU)
1964 		cpu_set_fpu_opts(c);
1965 	else
1966 		cpu_set_nofpu_opts(c);
1967 
1968 	if (cpu_has_mips_r2_r6) {
1969 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1970 		/* R2 has Performance Counter Interrupt indicator */
1971 		c->options |= MIPS_CPU_PCI;
1972 	}
1973 	else
1974 		c->srsets = 1;
1975 
1976 	if (cpu_has_mips_r6)
1977 		elf_hwcap |= HWCAP_MIPS_R6;
1978 
1979 	if (cpu_has_msa) {
1980 		c->msa_id = cpu_get_msa_id();
1981 		WARN(c->msa_id & MSA_IR_WRPF,
1982 		     "Vector register partitioning unimplemented!");
1983 		elf_hwcap |= HWCAP_MIPS_MSA;
1984 	}
1985 
1986 	if (cpu_has_mips16)
1987 		elf_hwcap |= HWCAP_MIPS_MIPS16;
1988 
1989 	if (cpu_has_mdmx)
1990 		elf_hwcap |= HWCAP_MIPS_MDMX;
1991 
1992 	if (cpu_has_mips3d)
1993 		elf_hwcap |= HWCAP_MIPS_MIPS3D;
1994 
1995 	if (cpu_has_smartmips)
1996 		elf_hwcap |= HWCAP_MIPS_SMARTMIPS;
1997 
1998 	if (cpu_has_dsp)
1999 		elf_hwcap |= HWCAP_MIPS_DSP;
2000 
2001 	if (cpu_has_dsp2)
2002 		elf_hwcap |= HWCAP_MIPS_DSP2;
2003 
2004 	if (cpu_has_dsp3)
2005 		elf_hwcap |= HWCAP_MIPS_DSP3;
2006 
2007 	if (cpu_has_mips16e2)
2008 		elf_hwcap |= HWCAP_MIPS_MIPS16E2;
2009 
2010 	if (cpu_has_loongson_mmi)
2011 		elf_hwcap |= HWCAP_LOONGSON_MMI;
2012 
2013 	if (cpu_has_loongson_ext)
2014 		elf_hwcap |= HWCAP_LOONGSON_EXT;
2015 
2016 	if (cpu_has_loongson_ext2)
2017 		elf_hwcap |= HWCAP_LOONGSON_EXT2;
2018 
2019 	if (cpu_has_vz)
2020 		cpu_probe_vz(c);
2021 
2022 	cpu_probe_vmbits(c);
2023 
2024 	/* Synthesize CPUCFG data if running on Loongson processors;
2025 	 * no-op otherwise.
2026 	 *
2027 	 * This looks at previously probed features, so keep this at bottom.
2028 	 */
2029 	loongson3_cpucfg_synthesize_data(c);
2030 
2031 #ifdef CONFIG_64BIT
2032 	if (cpu == 0)
2033 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
2034 #endif
2035 
2036 	reserve_exception_space(0, 0x1000);
2037 }
2038 
2039 void cpu_report(void)
2040 {
2041 	struct cpuinfo_mips *c = &current_cpu_data;
2042 
2043 	pr_info("CPU%d revision is: %08x (%s)\n",
2044 		smp_processor_id(), c->processor_id, cpu_name_string());
2045 	if (c->options & MIPS_CPU_FPU)
2046 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
2047 	if (cpu_has_msa)
2048 		pr_info("MSA revision is: %08x\n", c->msa_id);
2049 }
2050 
2051 void cpu_set_cluster(struct cpuinfo_mips *cpuinfo, unsigned int cluster)
2052 {
2053 	/* Ensure the core number fits in the field */
2054 	WARN_ON(cluster > (MIPS_GLOBALNUMBER_CLUSTER >>
2055 			   MIPS_GLOBALNUMBER_CLUSTER_SHF));
2056 
2057 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_CLUSTER;
2058 	cpuinfo->globalnumber |= cluster << MIPS_GLOBALNUMBER_CLUSTER_SHF;
2059 }
2060 
2061 void cpu_set_core(struct cpuinfo_mips *cpuinfo, unsigned int core)
2062 {
2063 	/* Ensure the core number fits in the field */
2064 	WARN_ON(core > (MIPS_GLOBALNUMBER_CORE >> MIPS_GLOBALNUMBER_CORE_SHF));
2065 
2066 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_CORE;
2067 	cpuinfo->globalnumber |= core << MIPS_GLOBALNUMBER_CORE_SHF;
2068 }
2069 
2070 void cpu_set_vpe_id(struct cpuinfo_mips *cpuinfo, unsigned int vpe)
2071 {
2072 	/* Ensure the VP(E) ID fits in the field */
2073 	WARN_ON(vpe > (MIPS_GLOBALNUMBER_VP >> MIPS_GLOBALNUMBER_VP_SHF));
2074 
2075 	/* Ensure we're not using VP(E)s without support */
2076 	WARN_ON(vpe && !IS_ENABLED(CONFIG_MIPS_MT_SMP) &&
2077 		!IS_ENABLED(CONFIG_CPU_MIPSR6));
2078 
2079 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_VP;
2080 	cpuinfo->globalnumber |= vpe << MIPS_GLOBALNUMBER_VP_SHF;
2081 }
2082