xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision be709d48)
1 /*
2  * Processor capabilities determination functions.
3  *
4  * Copyright (C) xxxx  the Anonymous
5  * Copyright (C) 1994 - 2006 Ralf Baechle
6  * Copyright (C) 2003, 2004  Maciej W. Rozycki
7  * Copyright (C) 2001, 2004, 2011, 2012	 MIPS Technologies, Inc.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/ptrace.h>
17 #include <linux/smp.h>
18 #include <linux/stddef.h>
19 #include <linux/export.h>
20 
21 #include <asm/bugs.h>
22 #include <asm/cpu.h>
23 #include <asm/cpu-features.h>
24 #include <asm/cpu-type.h>
25 #include <asm/fpu.h>
26 #include <asm/mipsregs.h>
27 #include <asm/mipsmtregs.h>
28 #include <asm/msa.h>
29 #include <asm/watch.h>
30 #include <asm/elf.h>
31 #include <asm/pgtable-bits.h>
32 #include <asm/spram.h>
33 #include <linux/uaccess.h>
34 
35 /* Hardware capabilities */
36 unsigned int elf_hwcap __read_mostly;
37 EXPORT_SYMBOL_GPL(elf_hwcap);
38 
39 #ifdef CONFIG_MIPS_FP_SUPPORT
40 
41 /*
42  * Get the FPU Implementation/Revision.
43  */
44 static inline unsigned long cpu_get_fpu_id(void)
45 {
46 	unsigned long tmp, fpu_id;
47 
48 	tmp = read_c0_status();
49 	__enable_fpu(FPU_AS_IS);
50 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
51 	write_c0_status(tmp);
52 	return fpu_id;
53 }
54 
55 /*
56  * Check if the CPU has an external FPU.
57  */
58 static inline int __cpu_has_fpu(void)
59 {
60 	return (cpu_get_fpu_id() & FPIR_IMP_MASK) != FPIR_IMP_NONE;
61 }
62 
63 /*
64  * Determine the FCSR mask for FPU hardware.
65  */
66 static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_mips *c)
67 {
68 	unsigned long sr, mask, fcsr, fcsr0, fcsr1;
69 
70 	fcsr = c->fpu_csr31;
71 	mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM;
72 
73 	sr = read_c0_status();
74 	__enable_fpu(FPU_AS_IS);
75 
76 	fcsr0 = fcsr & mask;
77 	write_32bit_cp1_register(CP1_STATUS, fcsr0);
78 	fcsr0 = read_32bit_cp1_register(CP1_STATUS);
79 
80 	fcsr1 = fcsr | ~mask;
81 	write_32bit_cp1_register(CP1_STATUS, fcsr1);
82 	fcsr1 = read_32bit_cp1_register(CP1_STATUS);
83 
84 	write_32bit_cp1_register(CP1_STATUS, fcsr);
85 
86 	write_c0_status(sr);
87 
88 	c->fpu_msk31 = ~(fcsr0 ^ fcsr1) & ~mask;
89 }
90 
91 /*
92  * Determine the IEEE 754 NaN encodings and ABS.fmt/NEG.fmt execution modes
93  * supported by FPU hardware.
94  */
95 static void cpu_set_fpu_2008(struct cpuinfo_mips *c)
96 {
97 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
98 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
99 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
100 		unsigned long sr, fir, fcsr, fcsr0, fcsr1;
101 
102 		sr = read_c0_status();
103 		__enable_fpu(FPU_AS_IS);
104 
105 		fir = read_32bit_cp1_register(CP1_REVISION);
106 		if (fir & MIPS_FPIR_HAS2008) {
107 			fcsr = read_32bit_cp1_register(CP1_STATUS);
108 
109 			fcsr0 = fcsr & ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
110 			write_32bit_cp1_register(CP1_STATUS, fcsr0);
111 			fcsr0 = read_32bit_cp1_register(CP1_STATUS);
112 
113 			fcsr1 = fcsr | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
114 			write_32bit_cp1_register(CP1_STATUS, fcsr1);
115 			fcsr1 = read_32bit_cp1_register(CP1_STATUS);
116 
117 			write_32bit_cp1_register(CP1_STATUS, fcsr);
118 
119 			if (!(fcsr0 & FPU_CSR_NAN2008))
120 				c->options |= MIPS_CPU_NAN_LEGACY;
121 			if (fcsr1 & FPU_CSR_NAN2008)
122 				c->options |= MIPS_CPU_NAN_2008;
123 
124 			if ((fcsr0 ^ fcsr1) & FPU_CSR_ABS2008)
125 				c->fpu_msk31 &= ~FPU_CSR_ABS2008;
126 			else
127 				c->fpu_csr31 |= fcsr & FPU_CSR_ABS2008;
128 
129 			if ((fcsr0 ^ fcsr1) & FPU_CSR_NAN2008)
130 				c->fpu_msk31 &= ~FPU_CSR_NAN2008;
131 			else
132 				c->fpu_csr31 |= fcsr & FPU_CSR_NAN2008;
133 		} else {
134 			c->options |= MIPS_CPU_NAN_LEGACY;
135 		}
136 
137 		write_c0_status(sr);
138 	} else {
139 		c->options |= MIPS_CPU_NAN_LEGACY;
140 	}
141 }
142 
143 /*
144  * IEEE 754 conformance mode to use.  Affects the NaN encoding and the
145  * ABS.fmt/NEG.fmt execution mode.
146  */
147 static enum { STRICT, LEGACY, STD2008, RELAXED } ieee754 = STRICT;
148 
149 /*
150  * Set the IEEE 754 NaN encodings and the ABS.fmt/NEG.fmt execution modes
151  * to support by the FPU emulator according to the IEEE 754 conformance
152  * mode selected.  Note that "relaxed" straps the emulator so that it
153  * allows 2008-NaN binaries even for legacy processors.
154  */
155 static void cpu_set_nofpu_2008(struct cpuinfo_mips *c)
156 {
157 	c->options &= ~(MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY);
158 	c->fpu_csr31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
159 	c->fpu_msk31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
160 
161 	switch (ieee754) {
162 	case STRICT:
163 		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
164 				    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
165 				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
166 			c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
167 		} else {
168 			c->options |= MIPS_CPU_NAN_LEGACY;
169 			c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
170 		}
171 		break;
172 	case LEGACY:
173 		c->options |= MIPS_CPU_NAN_LEGACY;
174 		c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
175 		break;
176 	case STD2008:
177 		c->options |= MIPS_CPU_NAN_2008;
178 		c->fpu_csr31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
179 		c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
180 		break;
181 	case RELAXED:
182 		c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
183 		break;
184 	}
185 }
186 
187 /*
188  * Override the IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode
189  * according to the "ieee754=" parameter.
190  */
191 static void cpu_set_nan_2008(struct cpuinfo_mips *c)
192 {
193 	switch (ieee754) {
194 	case STRICT:
195 		mips_use_nan_legacy = !!cpu_has_nan_legacy;
196 		mips_use_nan_2008 = !!cpu_has_nan_2008;
197 		break;
198 	case LEGACY:
199 		mips_use_nan_legacy = !!cpu_has_nan_legacy;
200 		mips_use_nan_2008 = !cpu_has_nan_legacy;
201 		break;
202 	case STD2008:
203 		mips_use_nan_legacy = !cpu_has_nan_2008;
204 		mips_use_nan_2008 = !!cpu_has_nan_2008;
205 		break;
206 	case RELAXED:
207 		mips_use_nan_legacy = true;
208 		mips_use_nan_2008 = true;
209 		break;
210 	}
211 }
212 
213 /*
214  * IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode override
215  * settings:
216  *
217  * strict:  accept binaries that request a NaN encoding supported by the FPU
218  * legacy:  only accept legacy-NaN binaries
219  * 2008:    only accept 2008-NaN binaries
220  * relaxed: accept any binaries regardless of whether supported by the FPU
221  */
222 static int __init ieee754_setup(char *s)
223 {
224 	if (!s)
225 		return -1;
226 	else if (!strcmp(s, "strict"))
227 		ieee754 = STRICT;
228 	else if (!strcmp(s, "legacy"))
229 		ieee754 = LEGACY;
230 	else if (!strcmp(s, "2008"))
231 		ieee754 = STD2008;
232 	else if (!strcmp(s, "relaxed"))
233 		ieee754 = RELAXED;
234 	else
235 		return -1;
236 
237 	if (!(boot_cpu_data.options & MIPS_CPU_FPU))
238 		cpu_set_nofpu_2008(&boot_cpu_data);
239 	cpu_set_nan_2008(&boot_cpu_data);
240 
241 	return 0;
242 }
243 
244 early_param("ieee754", ieee754_setup);
245 
246 /*
247  * Set the FIR feature flags for the FPU emulator.
248  */
249 static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
250 {
251 	u32 value;
252 
253 	value = 0;
254 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
255 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
256 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
257 		value |= MIPS_FPIR_D | MIPS_FPIR_S;
258 	if (c->isa_level & (MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
259 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
260 		value |= MIPS_FPIR_F64 | MIPS_FPIR_L | MIPS_FPIR_W;
261 	if (c->options & MIPS_CPU_NAN_2008)
262 		value |= MIPS_FPIR_HAS2008;
263 	c->fpu_id = value;
264 }
265 
266 /* Determined FPU emulator mask to use for the boot CPU with "nofpu".  */
267 static unsigned int mips_nofpu_msk31;
268 
269 /*
270  * Set options for FPU hardware.
271  */
272 static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
273 {
274 	c->fpu_id = cpu_get_fpu_id();
275 	mips_nofpu_msk31 = c->fpu_msk31;
276 
277 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
278 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
279 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
280 		if (c->fpu_id & MIPS_FPIR_3D)
281 			c->ases |= MIPS_ASE_MIPS3D;
282 		if (c->fpu_id & MIPS_FPIR_UFRP)
283 			c->options |= MIPS_CPU_UFR;
284 		if (c->fpu_id & MIPS_FPIR_FREP)
285 			c->options |= MIPS_CPU_FRE;
286 	}
287 
288 	cpu_set_fpu_fcsr_mask(c);
289 	cpu_set_fpu_2008(c);
290 	cpu_set_nan_2008(c);
291 }
292 
293 /*
294  * Set options for the FPU emulator.
295  */
296 static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
297 {
298 	c->options &= ~MIPS_CPU_FPU;
299 	c->fpu_msk31 = mips_nofpu_msk31;
300 
301 	cpu_set_nofpu_2008(c);
302 	cpu_set_nan_2008(c);
303 	cpu_set_nofpu_id(c);
304 }
305 
306 static int mips_fpu_disabled;
307 
308 static int __init fpu_disable(char *s)
309 {
310 	cpu_set_nofpu_opts(&boot_cpu_data);
311 	mips_fpu_disabled = 1;
312 
313 	return 1;
314 }
315 
316 __setup("nofpu", fpu_disable);
317 
318 #else /* !CONFIG_MIPS_FP_SUPPORT */
319 
320 #define mips_fpu_disabled 1
321 
322 static inline unsigned long cpu_get_fpu_id(void)
323 {
324 	return FPIR_IMP_NONE;
325 }
326 
327 static inline int __cpu_has_fpu(void)
328 {
329 	return 0;
330 }
331 
332 static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
333 {
334 	/* no-op */
335 }
336 
337 static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
338 {
339 	/* no-op */
340 }
341 
342 #endif /* CONFIG_MIPS_FP_SUPPORT */
343 
344 static inline unsigned long cpu_get_msa_id(void)
345 {
346 	unsigned long status, msa_id;
347 
348 	status = read_c0_status();
349 	__enable_fpu(FPU_64BIT);
350 	enable_msa();
351 	msa_id = read_msa_ir();
352 	disable_msa();
353 	write_c0_status(status);
354 	return msa_id;
355 }
356 
357 static int mips_dsp_disabled;
358 
359 static int __init dsp_disable(char *s)
360 {
361 	cpu_data[0].ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
362 	mips_dsp_disabled = 1;
363 
364 	return 1;
365 }
366 
367 __setup("nodsp", dsp_disable);
368 
369 static int mips_htw_disabled;
370 
371 static int __init htw_disable(char *s)
372 {
373 	mips_htw_disabled = 1;
374 	cpu_data[0].options &= ~MIPS_CPU_HTW;
375 	write_c0_pwctl(read_c0_pwctl() &
376 		       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
377 
378 	return 1;
379 }
380 
381 __setup("nohtw", htw_disable);
382 
383 static int mips_ftlb_disabled;
384 static int mips_has_ftlb_configured;
385 
386 enum ftlb_flags {
387 	FTLB_EN		= 1 << 0,
388 	FTLB_SET_PROB	= 1 << 1,
389 };
390 
391 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags);
392 
393 static int __init ftlb_disable(char *s)
394 {
395 	unsigned int config4, mmuextdef;
396 
397 	/*
398 	 * If the core hasn't done any FTLB configuration, there is nothing
399 	 * for us to do here.
400 	 */
401 	if (!mips_has_ftlb_configured)
402 		return 1;
403 
404 	/* Disable it in the boot cpu */
405 	if (set_ftlb_enable(&cpu_data[0], 0)) {
406 		pr_warn("Can't turn FTLB off\n");
407 		return 1;
408 	}
409 
410 	config4 = read_c0_config4();
411 
412 	/* Check that FTLB has been disabled */
413 	mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
414 	/* MMUSIZEEXT == VTLB ON, FTLB OFF */
415 	if (mmuextdef == MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT) {
416 		/* This should never happen */
417 		pr_warn("FTLB could not be disabled!\n");
418 		return 1;
419 	}
420 
421 	mips_ftlb_disabled = 1;
422 	mips_has_ftlb_configured = 0;
423 
424 	/*
425 	 * noftlb is mainly used for debug purposes so print
426 	 * an informative message instead of using pr_debug()
427 	 */
428 	pr_info("FTLB has been disabled\n");
429 
430 	/*
431 	 * Some of these bits are duplicated in the decode_config4.
432 	 * MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT is the only possible case
433 	 * once FTLB has been disabled so undo what decode_config4 did.
434 	 */
435 	cpu_data[0].tlbsize -= cpu_data[0].tlbsizeftlbways *
436 			       cpu_data[0].tlbsizeftlbsets;
437 	cpu_data[0].tlbsizeftlbsets = 0;
438 	cpu_data[0].tlbsizeftlbways = 0;
439 
440 	return 1;
441 }
442 
443 __setup("noftlb", ftlb_disable);
444 
445 /*
446  * Check if the CPU has per tc perf counters
447  */
448 static inline void cpu_set_mt_per_tc_perf(struct cpuinfo_mips *c)
449 {
450 	if (read_c0_config7() & MTI_CONF7_PTC)
451 		c->options |= MIPS_CPU_MT_PER_TC_PERF_COUNTERS;
452 }
453 
454 static inline void check_errata(void)
455 {
456 	struct cpuinfo_mips *c = &current_cpu_data;
457 
458 	switch (current_cpu_type()) {
459 	case CPU_34K:
460 		/*
461 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
462 		 * This code only handles VPE0, any SMP/RTOS code
463 		 * making use of VPE1 will be responsable for that VPE.
464 		 */
465 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
466 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
467 		break;
468 	default:
469 		break;
470 	}
471 }
472 
473 void __init check_bugs32(void)
474 {
475 	check_errata();
476 }
477 
478 /*
479  * Probe whether cpu has config register by trying to play with
480  * alternate cache bit and see whether it matters.
481  * It's used by cpu_probe to distinguish between R3000A and R3081.
482  */
483 static inline int cpu_has_confreg(void)
484 {
485 #ifdef CONFIG_CPU_R3000
486 	extern unsigned long r3k_cache_size(unsigned long);
487 	unsigned long size1, size2;
488 	unsigned long cfg = read_c0_conf();
489 
490 	size1 = r3k_cache_size(ST0_ISC);
491 	write_c0_conf(cfg ^ R30XX_CONF_AC);
492 	size2 = r3k_cache_size(ST0_ISC);
493 	write_c0_conf(cfg);
494 	return size1 != size2;
495 #else
496 	return 0;
497 #endif
498 }
499 
500 static inline void set_elf_platform(int cpu, const char *plat)
501 {
502 	if (cpu == 0)
503 		__elf_platform = plat;
504 }
505 
506 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
507 {
508 #ifdef __NEED_VMBITS_PROBE
509 	write_c0_entryhi(0x3fffffffffffe000ULL);
510 	back_to_back_c0_hazard();
511 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
512 #endif
513 }
514 
515 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
516 {
517 	switch (isa) {
518 	case MIPS_CPU_ISA_M64R2:
519 		c->isa_level |= MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2;
520 		/* fall through */
521 	case MIPS_CPU_ISA_M64R1:
522 		c->isa_level |= MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1;
523 		/* fall through */
524 	case MIPS_CPU_ISA_V:
525 		c->isa_level |= MIPS_CPU_ISA_V;
526 		/* fall through */
527 	case MIPS_CPU_ISA_IV:
528 		c->isa_level |= MIPS_CPU_ISA_IV;
529 		/* fall through */
530 	case MIPS_CPU_ISA_III:
531 		c->isa_level |= MIPS_CPU_ISA_II | MIPS_CPU_ISA_III;
532 		break;
533 
534 	/* R6 incompatible with everything else */
535 	case MIPS_CPU_ISA_M64R6:
536 		c->isa_level |= MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6;
537 		/* fall through */
538 	case MIPS_CPU_ISA_M32R6:
539 		c->isa_level |= MIPS_CPU_ISA_M32R6;
540 		/* Break here so we don't add incompatible ISAs */
541 		break;
542 	case MIPS_CPU_ISA_M32R2:
543 		c->isa_level |= MIPS_CPU_ISA_M32R2;
544 		/* fall through */
545 	case MIPS_CPU_ISA_M32R1:
546 		c->isa_level |= MIPS_CPU_ISA_M32R1;
547 		/* fall through */
548 	case MIPS_CPU_ISA_II:
549 		c->isa_level |= MIPS_CPU_ISA_II;
550 		break;
551 	}
552 }
553 
554 static char unknown_isa[] = KERN_ERR \
555 	"Unsupported ISA type, c0.config0: %d.";
556 
557 static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
558 {
559 
560 	unsigned int probability = c->tlbsize / c->tlbsizevtlb;
561 
562 	/*
563 	 * 0 = All TLBWR instructions go to FTLB
564 	 * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
565 	 * FTLB and 1 goes to the VTLB.
566 	 * 2 = 7:1: As above with 7:1 ratio.
567 	 * 3 = 3:1: As above with 3:1 ratio.
568 	 *
569 	 * Use the linear midpoint as the probability threshold.
570 	 */
571 	if (probability >= 12)
572 		return 1;
573 	else if (probability >= 6)
574 		return 2;
575 	else
576 		/*
577 		 * So FTLB is less than 4 times bigger than VTLB.
578 		 * A 3:1 ratio can still be useful though.
579 		 */
580 		return 3;
581 }
582 
583 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags)
584 {
585 	unsigned int config;
586 
587 	/* It's implementation dependent how the FTLB can be enabled */
588 	switch (c->cputype) {
589 	case CPU_PROAPTIV:
590 	case CPU_P5600:
591 	case CPU_P6600:
592 		/* proAptiv & related cores use Config6 to enable the FTLB */
593 		config = read_c0_config6();
594 
595 		if (flags & FTLB_EN)
596 			config |= MIPS_CONF6_FTLBEN;
597 		else
598 			config &= ~MIPS_CONF6_FTLBEN;
599 
600 		if (flags & FTLB_SET_PROB) {
601 			config &= ~(3 << MIPS_CONF6_FTLBP_SHIFT);
602 			config |= calculate_ftlb_probability(c)
603 				  << MIPS_CONF6_FTLBP_SHIFT;
604 		}
605 
606 		write_c0_config6(config);
607 		back_to_back_c0_hazard();
608 		break;
609 	case CPU_I6400:
610 	case CPU_I6500:
611 		/* There's no way to disable the FTLB */
612 		if (!(flags & FTLB_EN))
613 			return 1;
614 		return 0;
615 	case CPU_LOONGSON3:
616 		/* Flush ITLB, DTLB, VTLB and FTLB */
617 		write_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB |
618 			      LOONGSON_DIAG_VTLB | LOONGSON_DIAG_FTLB);
619 		/* Loongson-3 cores use Config6 to enable the FTLB */
620 		config = read_c0_config6();
621 		if (flags & FTLB_EN)
622 			/* Enable FTLB */
623 			write_c0_config6(config & ~MIPS_CONF6_FTLBDIS);
624 		else
625 			/* Disable FTLB */
626 			write_c0_config6(config | MIPS_CONF6_FTLBDIS);
627 		break;
628 	default:
629 		return 1;
630 	}
631 
632 	return 0;
633 }
634 
635 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
636 {
637 	unsigned int config0;
638 	int isa, mt;
639 
640 	config0 = read_c0_config();
641 
642 	/*
643 	 * Look for Standard TLB or Dual VTLB and FTLB
644 	 */
645 	mt = config0 & MIPS_CONF_MT;
646 	if (mt == MIPS_CONF_MT_TLB)
647 		c->options |= MIPS_CPU_TLB;
648 	else if (mt == MIPS_CONF_MT_FTLB)
649 		c->options |= MIPS_CPU_TLB | MIPS_CPU_FTLB;
650 
651 	isa = (config0 & MIPS_CONF_AT) >> 13;
652 	switch (isa) {
653 	case 0:
654 		switch ((config0 & MIPS_CONF_AR) >> 10) {
655 		case 0:
656 			set_isa(c, MIPS_CPU_ISA_M32R1);
657 			break;
658 		case 1:
659 			set_isa(c, MIPS_CPU_ISA_M32R2);
660 			break;
661 		case 2:
662 			set_isa(c, MIPS_CPU_ISA_M32R6);
663 			break;
664 		default:
665 			goto unknown;
666 		}
667 		break;
668 	case 2:
669 		switch ((config0 & MIPS_CONF_AR) >> 10) {
670 		case 0:
671 			set_isa(c, MIPS_CPU_ISA_M64R1);
672 			break;
673 		case 1:
674 			set_isa(c, MIPS_CPU_ISA_M64R2);
675 			break;
676 		case 2:
677 			set_isa(c, MIPS_CPU_ISA_M64R6);
678 			break;
679 		default:
680 			goto unknown;
681 		}
682 		break;
683 	default:
684 		goto unknown;
685 	}
686 
687 	return config0 & MIPS_CONF_M;
688 
689 unknown:
690 	panic(unknown_isa, config0);
691 }
692 
693 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
694 {
695 	unsigned int config1;
696 
697 	config1 = read_c0_config1();
698 
699 	if (config1 & MIPS_CONF1_MD)
700 		c->ases |= MIPS_ASE_MDMX;
701 	if (config1 & MIPS_CONF1_PC)
702 		c->options |= MIPS_CPU_PERF;
703 	if (config1 & MIPS_CONF1_WR)
704 		c->options |= MIPS_CPU_WATCH;
705 	if (config1 & MIPS_CONF1_CA)
706 		c->ases |= MIPS_ASE_MIPS16;
707 	if (config1 & MIPS_CONF1_EP)
708 		c->options |= MIPS_CPU_EJTAG;
709 	if (config1 & MIPS_CONF1_FP) {
710 		c->options |= MIPS_CPU_FPU;
711 		c->options |= MIPS_CPU_32FPR;
712 	}
713 	if (cpu_has_tlb) {
714 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
715 		c->tlbsizevtlb = c->tlbsize;
716 		c->tlbsizeftlbsets = 0;
717 	}
718 
719 	return config1 & MIPS_CONF_M;
720 }
721 
722 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
723 {
724 	unsigned int config2;
725 
726 	config2 = read_c0_config2();
727 
728 	if (config2 & MIPS_CONF2_SL)
729 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
730 
731 	return config2 & MIPS_CONF_M;
732 }
733 
734 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
735 {
736 	unsigned int config3;
737 
738 	config3 = read_c0_config3();
739 
740 	if (config3 & MIPS_CONF3_SM) {
741 		c->ases |= MIPS_ASE_SMARTMIPS;
742 		c->options |= MIPS_CPU_RIXI | MIPS_CPU_CTXTC;
743 	}
744 	if (config3 & MIPS_CONF3_RXI)
745 		c->options |= MIPS_CPU_RIXI;
746 	if (config3 & MIPS_CONF3_CTXTC)
747 		c->options |= MIPS_CPU_CTXTC;
748 	if (config3 & MIPS_CONF3_DSP)
749 		c->ases |= MIPS_ASE_DSP;
750 	if (config3 & MIPS_CONF3_DSP2P) {
751 		c->ases |= MIPS_ASE_DSP2P;
752 		if (cpu_has_mips_r6)
753 			c->ases |= MIPS_ASE_DSP3;
754 	}
755 	if (config3 & MIPS_CONF3_VINT)
756 		c->options |= MIPS_CPU_VINT;
757 	if (config3 & MIPS_CONF3_VEIC)
758 		c->options |= MIPS_CPU_VEIC;
759 	if (config3 & MIPS_CONF3_LPA)
760 		c->options |= MIPS_CPU_LPA;
761 	if (config3 & MIPS_CONF3_MT)
762 		c->ases |= MIPS_ASE_MIPSMT;
763 	if (config3 & MIPS_CONF3_ULRI)
764 		c->options |= MIPS_CPU_ULRI;
765 	if (config3 & MIPS_CONF3_ISA)
766 		c->options |= MIPS_CPU_MICROMIPS;
767 	if (config3 & MIPS_CONF3_VZ)
768 		c->ases |= MIPS_ASE_VZ;
769 	if (config3 & MIPS_CONF3_SC)
770 		c->options |= MIPS_CPU_SEGMENTS;
771 	if (config3 & MIPS_CONF3_BI)
772 		c->options |= MIPS_CPU_BADINSTR;
773 	if (config3 & MIPS_CONF3_BP)
774 		c->options |= MIPS_CPU_BADINSTRP;
775 	if (config3 & MIPS_CONF3_MSA)
776 		c->ases |= MIPS_ASE_MSA;
777 	if (config3 & MIPS_CONF3_PW) {
778 		c->htw_seq = 0;
779 		c->options |= MIPS_CPU_HTW;
780 	}
781 	if (config3 & MIPS_CONF3_CDMM)
782 		c->options |= MIPS_CPU_CDMM;
783 	if (config3 & MIPS_CONF3_SP)
784 		c->options |= MIPS_CPU_SP;
785 
786 	return config3 & MIPS_CONF_M;
787 }
788 
789 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
790 {
791 	unsigned int config4;
792 	unsigned int newcf4;
793 	unsigned int mmuextdef;
794 	unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE;
795 	unsigned long asid_mask;
796 
797 	config4 = read_c0_config4();
798 
799 	if (cpu_has_tlb) {
800 		if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
801 			c->options |= MIPS_CPU_TLBINV;
802 
803 		/*
804 		 * R6 has dropped the MMUExtDef field from config4.
805 		 * On R6 the fields always describe the FTLB, and only if it is
806 		 * present according to Config.MT.
807 		 */
808 		if (!cpu_has_mips_r6)
809 			mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
810 		else if (cpu_has_ftlb)
811 			mmuextdef = MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT;
812 		else
813 			mmuextdef = 0;
814 
815 		switch (mmuextdef) {
816 		case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT:
817 			c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
818 			c->tlbsizevtlb = c->tlbsize;
819 			break;
820 		case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
821 			c->tlbsizevtlb +=
822 				((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
823 				  MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40;
824 			c->tlbsize = c->tlbsizevtlb;
825 			ftlb_page = MIPS_CONF4_VFTLBPAGESIZE;
826 			/* fall through */
827 		case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
828 			if (mips_ftlb_disabled)
829 				break;
830 			newcf4 = (config4 & ~ftlb_page) |
831 				(page_size_ftlb(mmuextdef) <<
832 				 MIPS_CONF4_FTLBPAGESIZE_SHIFT);
833 			write_c0_config4(newcf4);
834 			back_to_back_c0_hazard();
835 			config4 = read_c0_config4();
836 			if (config4 != newcf4) {
837 				pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n",
838 				       PAGE_SIZE, config4);
839 				/* Switch FTLB off */
840 				set_ftlb_enable(c, 0);
841 				mips_ftlb_disabled = 1;
842 				break;
843 			}
844 			c->tlbsizeftlbsets = 1 <<
845 				((config4 & MIPS_CONF4_FTLBSETS) >>
846 				 MIPS_CONF4_FTLBSETS_SHIFT);
847 			c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >>
848 					      MIPS_CONF4_FTLBWAYS_SHIFT) + 2;
849 			c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets;
850 			mips_has_ftlb_configured = 1;
851 			break;
852 		}
853 	}
854 
855 	c->kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
856 				>> MIPS_CONF4_KSCREXIST_SHIFT;
857 
858 	asid_mask = MIPS_ENTRYHI_ASID;
859 	if (config4 & MIPS_CONF4_AE)
860 		asid_mask |= MIPS_ENTRYHI_ASIDX;
861 	set_cpu_asid_mask(c, asid_mask);
862 
863 	/*
864 	 * Warn if the computed ASID mask doesn't match the mask the kernel
865 	 * is built for. This may indicate either a serious problem or an
866 	 * easy optimisation opportunity, but either way should be addressed.
867 	 */
868 	WARN_ON(asid_mask != cpu_asid_mask(c));
869 
870 	return config4 & MIPS_CONF_M;
871 }
872 
873 static inline unsigned int decode_config5(struct cpuinfo_mips *c)
874 {
875 	unsigned int config5, max_mmid_width;
876 	unsigned long asid_mask;
877 
878 	config5 = read_c0_config5();
879 	config5 &= ~(MIPS_CONF5_UFR | MIPS_CONF5_UFE);
880 
881 	if (cpu_has_mips_r6) {
882 		if (!__builtin_constant_p(cpu_has_mmid) || cpu_has_mmid)
883 			config5 |= MIPS_CONF5_MI;
884 		else
885 			config5 &= ~MIPS_CONF5_MI;
886 	}
887 
888 	write_c0_config5(config5);
889 
890 	if (config5 & MIPS_CONF5_EVA)
891 		c->options |= MIPS_CPU_EVA;
892 	if (config5 & MIPS_CONF5_MRP)
893 		c->options |= MIPS_CPU_MAAR;
894 	if (config5 & MIPS_CONF5_LLB)
895 		c->options |= MIPS_CPU_RW_LLB;
896 	if (config5 & MIPS_CONF5_MVH)
897 		c->options |= MIPS_CPU_MVH;
898 	if (cpu_has_mips_r6 && (config5 & MIPS_CONF5_VP))
899 		c->options |= MIPS_CPU_VP;
900 	if (config5 & MIPS_CONF5_CA2)
901 		c->ases |= MIPS_ASE_MIPS16E2;
902 
903 	if (config5 & MIPS_CONF5_CRCP)
904 		elf_hwcap |= HWCAP_MIPS_CRC32;
905 
906 	if (cpu_has_mips_r6) {
907 		/* Ensure the write to config5 above takes effect */
908 		back_to_back_c0_hazard();
909 
910 		/* Check whether we successfully enabled MMID support */
911 		config5 = read_c0_config5();
912 		if (config5 & MIPS_CONF5_MI)
913 			c->options |= MIPS_CPU_MMID;
914 
915 		/*
916 		 * Warn if we've hardcoded cpu_has_mmid to a value unsuitable
917 		 * for the CPU we're running on, or if CPUs in an SMP system
918 		 * have inconsistent MMID support.
919 		 */
920 		WARN_ON(!!cpu_has_mmid != !!(config5 & MIPS_CONF5_MI));
921 
922 		if (cpu_has_mmid) {
923 			write_c0_memorymapid(~0ul);
924 			back_to_back_c0_hazard();
925 			asid_mask = read_c0_memorymapid();
926 
927 			/*
928 			 * We maintain a bitmap to track MMID allocation, and
929 			 * need a sensible upper bound on the size of that
930 			 * bitmap. The initial CPU with MMID support (I6500)
931 			 * supports 16 bit MMIDs, which gives us an 8KiB
932 			 * bitmap. The architecture recommends that hardware
933 			 * support 32 bit MMIDs, which would give us a 512MiB
934 			 * bitmap - that's too big in most cases.
935 			 *
936 			 * Cap MMID width at 16 bits for now & we can revisit
937 			 * this if & when hardware supports anything wider.
938 			 */
939 			max_mmid_width = 16;
940 			if (asid_mask > GENMASK(max_mmid_width - 1, 0)) {
941 				pr_info("Capping MMID width at %d bits",
942 					max_mmid_width);
943 				asid_mask = GENMASK(max_mmid_width - 1, 0);
944 			}
945 
946 			set_cpu_asid_mask(c, asid_mask);
947 		}
948 	}
949 
950 	return config5 & MIPS_CONF_M;
951 }
952 
953 static void decode_configs(struct cpuinfo_mips *c)
954 {
955 	int ok;
956 
957 	/* MIPS32 or MIPS64 compliant CPU.  */
958 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
959 		     MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
960 
961 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
962 
963 	/* Enable FTLB if present and not disabled */
964 	set_ftlb_enable(c, mips_ftlb_disabled ? 0 : FTLB_EN);
965 
966 	ok = decode_config0(c);			/* Read Config registers.  */
967 	BUG_ON(!ok);				/* Arch spec violation!	 */
968 	if (ok)
969 		ok = decode_config1(c);
970 	if (ok)
971 		ok = decode_config2(c);
972 	if (ok)
973 		ok = decode_config3(c);
974 	if (ok)
975 		ok = decode_config4(c);
976 	if (ok)
977 		ok = decode_config5(c);
978 
979 	/* Probe the EBase.WG bit */
980 	if (cpu_has_mips_r2_r6) {
981 		u64 ebase;
982 		unsigned int status;
983 
984 		/* {read,write}_c0_ebase_64() may be UNDEFINED prior to r6 */
985 		ebase = cpu_has_mips64r6 ? read_c0_ebase_64()
986 					 : (s32)read_c0_ebase();
987 		if (ebase & MIPS_EBASE_WG) {
988 			/* WG bit already set, we can avoid the clumsy probe */
989 			c->options |= MIPS_CPU_EBASE_WG;
990 		} else {
991 			/* Its UNDEFINED to change EBase while BEV=0 */
992 			status = read_c0_status();
993 			write_c0_status(status | ST0_BEV);
994 			irq_enable_hazard();
995 			/*
996 			 * On pre-r6 cores, this may well clobber the upper bits
997 			 * of EBase. This is hard to avoid without potentially
998 			 * hitting UNDEFINED dm*c0 behaviour if EBase is 32-bit.
999 			 */
1000 			if (cpu_has_mips64r6)
1001 				write_c0_ebase_64(ebase | MIPS_EBASE_WG);
1002 			else
1003 				write_c0_ebase(ebase | MIPS_EBASE_WG);
1004 			back_to_back_c0_hazard();
1005 			/* Restore BEV */
1006 			write_c0_status(status);
1007 			if (read_c0_ebase() & MIPS_EBASE_WG) {
1008 				c->options |= MIPS_CPU_EBASE_WG;
1009 				write_c0_ebase(ebase);
1010 			}
1011 		}
1012 	}
1013 
1014 	/* configure the FTLB write probability */
1015 	set_ftlb_enable(c, (mips_ftlb_disabled ? 0 : FTLB_EN) | FTLB_SET_PROB);
1016 
1017 	mips_probe_watch_registers(c);
1018 
1019 #ifndef CONFIG_MIPS_CPS
1020 	if (cpu_has_mips_r2_r6) {
1021 		unsigned int core;
1022 
1023 		core = get_ebase_cpunum();
1024 		if (cpu_has_mipsmt)
1025 			core >>= fls(core_nvpes()) - 1;
1026 		cpu_set_core(c, core);
1027 	}
1028 #endif
1029 }
1030 
1031 /*
1032  * Probe for certain guest capabilities by writing config bits and reading back.
1033  * Finally write back the original value.
1034  */
1035 #define probe_gc0_config(name, maxconf, bits)				\
1036 do {									\
1037 	unsigned int tmp;						\
1038 	tmp = read_gc0_##name();					\
1039 	write_gc0_##name(tmp | (bits));					\
1040 	back_to_back_c0_hazard();					\
1041 	maxconf = read_gc0_##name();					\
1042 	write_gc0_##name(tmp);						\
1043 } while (0)
1044 
1045 /*
1046  * Probe for dynamic guest capabilities by changing certain config bits and
1047  * reading back to see if they change. Finally write back the original value.
1048  */
1049 #define probe_gc0_config_dyn(name, maxconf, dynconf, bits)		\
1050 do {									\
1051 	maxconf = read_gc0_##name();					\
1052 	write_gc0_##name(maxconf ^ (bits));				\
1053 	back_to_back_c0_hazard();					\
1054 	dynconf = maxconf ^ read_gc0_##name();				\
1055 	write_gc0_##name(maxconf);					\
1056 	maxconf |= dynconf;						\
1057 } while (0)
1058 
1059 static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c)
1060 {
1061 	unsigned int config0;
1062 
1063 	probe_gc0_config(config, config0, MIPS_CONF_M);
1064 
1065 	if (config0 & MIPS_CONF_M)
1066 		c->guest.conf |= BIT(1);
1067 	return config0 & MIPS_CONF_M;
1068 }
1069 
1070 static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c)
1071 {
1072 	unsigned int config1, config1_dyn;
1073 
1074 	probe_gc0_config_dyn(config1, config1, config1_dyn,
1075 			     MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR |
1076 			     MIPS_CONF1_FP);
1077 
1078 	if (config1 & MIPS_CONF1_FP)
1079 		c->guest.options |= MIPS_CPU_FPU;
1080 	if (config1_dyn & MIPS_CONF1_FP)
1081 		c->guest.options_dyn |= MIPS_CPU_FPU;
1082 
1083 	if (config1 & MIPS_CONF1_WR)
1084 		c->guest.options |= MIPS_CPU_WATCH;
1085 	if (config1_dyn & MIPS_CONF1_WR)
1086 		c->guest.options_dyn |= MIPS_CPU_WATCH;
1087 
1088 	if (config1 & MIPS_CONF1_PC)
1089 		c->guest.options |= MIPS_CPU_PERF;
1090 	if (config1_dyn & MIPS_CONF1_PC)
1091 		c->guest.options_dyn |= MIPS_CPU_PERF;
1092 
1093 	if (config1 & MIPS_CONF_M)
1094 		c->guest.conf |= BIT(2);
1095 	return config1 & MIPS_CONF_M;
1096 }
1097 
1098 static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c)
1099 {
1100 	unsigned int config2;
1101 
1102 	probe_gc0_config(config2, config2, MIPS_CONF_M);
1103 
1104 	if (config2 & MIPS_CONF_M)
1105 		c->guest.conf |= BIT(3);
1106 	return config2 & MIPS_CONF_M;
1107 }
1108 
1109 static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c)
1110 {
1111 	unsigned int config3, config3_dyn;
1112 
1113 	probe_gc0_config_dyn(config3, config3, config3_dyn,
1114 			     MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_ULRI |
1115 			     MIPS_CONF3_CTXTC);
1116 
1117 	if (config3 & MIPS_CONF3_CTXTC)
1118 		c->guest.options |= MIPS_CPU_CTXTC;
1119 	if (config3_dyn & MIPS_CONF3_CTXTC)
1120 		c->guest.options_dyn |= MIPS_CPU_CTXTC;
1121 
1122 	if (config3 & MIPS_CONF3_PW)
1123 		c->guest.options |= MIPS_CPU_HTW;
1124 
1125 	if (config3 & MIPS_CONF3_ULRI)
1126 		c->guest.options |= MIPS_CPU_ULRI;
1127 
1128 	if (config3 & MIPS_CONF3_SC)
1129 		c->guest.options |= MIPS_CPU_SEGMENTS;
1130 
1131 	if (config3 & MIPS_CONF3_BI)
1132 		c->guest.options |= MIPS_CPU_BADINSTR;
1133 	if (config3 & MIPS_CONF3_BP)
1134 		c->guest.options |= MIPS_CPU_BADINSTRP;
1135 
1136 	if (config3 & MIPS_CONF3_MSA)
1137 		c->guest.ases |= MIPS_ASE_MSA;
1138 	if (config3_dyn & MIPS_CONF3_MSA)
1139 		c->guest.ases_dyn |= MIPS_ASE_MSA;
1140 
1141 	if (config3 & MIPS_CONF_M)
1142 		c->guest.conf |= BIT(4);
1143 	return config3 & MIPS_CONF_M;
1144 }
1145 
1146 static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c)
1147 {
1148 	unsigned int config4;
1149 
1150 	probe_gc0_config(config4, config4,
1151 			 MIPS_CONF_M | MIPS_CONF4_KSCREXIST);
1152 
1153 	c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
1154 				>> MIPS_CONF4_KSCREXIST_SHIFT;
1155 
1156 	if (config4 & MIPS_CONF_M)
1157 		c->guest.conf |= BIT(5);
1158 	return config4 & MIPS_CONF_M;
1159 }
1160 
1161 static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c)
1162 {
1163 	unsigned int config5, config5_dyn;
1164 
1165 	probe_gc0_config_dyn(config5, config5, config5_dyn,
1166 			 MIPS_CONF_M | MIPS_CONF5_MVH | MIPS_CONF5_MRP);
1167 
1168 	if (config5 & MIPS_CONF5_MRP)
1169 		c->guest.options |= MIPS_CPU_MAAR;
1170 	if (config5_dyn & MIPS_CONF5_MRP)
1171 		c->guest.options_dyn |= MIPS_CPU_MAAR;
1172 
1173 	if (config5 & MIPS_CONF5_LLB)
1174 		c->guest.options |= MIPS_CPU_RW_LLB;
1175 
1176 	if (config5 & MIPS_CONF5_MVH)
1177 		c->guest.options |= MIPS_CPU_MVH;
1178 
1179 	if (config5 & MIPS_CONF_M)
1180 		c->guest.conf |= BIT(6);
1181 	return config5 & MIPS_CONF_M;
1182 }
1183 
1184 static inline void decode_guest_configs(struct cpuinfo_mips *c)
1185 {
1186 	unsigned int ok;
1187 
1188 	ok = decode_guest_config0(c);
1189 	if (ok)
1190 		ok = decode_guest_config1(c);
1191 	if (ok)
1192 		ok = decode_guest_config2(c);
1193 	if (ok)
1194 		ok = decode_guest_config3(c);
1195 	if (ok)
1196 		ok = decode_guest_config4(c);
1197 	if (ok)
1198 		decode_guest_config5(c);
1199 }
1200 
1201 static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c)
1202 {
1203 	unsigned int guestctl0, temp;
1204 
1205 	guestctl0 = read_c0_guestctl0();
1206 
1207 	if (guestctl0 & MIPS_GCTL0_G0E)
1208 		c->options |= MIPS_CPU_GUESTCTL0EXT;
1209 	if (guestctl0 & MIPS_GCTL0_G1)
1210 		c->options |= MIPS_CPU_GUESTCTL1;
1211 	if (guestctl0 & MIPS_GCTL0_G2)
1212 		c->options |= MIPS_CPU_GUESTCTL2;
1213 	if (!(guestctl0 & MIPS_GCTL0_RAD)) {
1214 		c->options |= MIPS_CPU_GUESTID;
1215 
1216 		/*
1217 		 * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0
1218 		 * first, otherwise all data accesses will be fully virtualised
1219 		 * as if they were performed by guest mode.
1220 		 */
1221 		write_c0_guestctl1(0);
1222 		tlbw_use_hazard();
1223 
1224 		write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG);
1225 		back_to_back_c0_hazard();
1226 		temp = read_c0_guestctl0();
1227 
1228 		if (temp & MIPS_GCTL0_DRG) {
1229 			write_c0_guestctl0(guestctl0);
1230 			c->options |= MIPS_CPU_DRG;
1231 		}
1232 	}
1233 }
1234 
1235 static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c)
1236 {
1237 	if (cpu_has_guestid) {
1238 		/* determine the number of bits of GuestID available */
1239 		write_c0_guestctl1(MIPS_GCTL1_ID);
1240 		back_to_back_c0_hazard();
1241 		c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID)
1242 						>> MIPS_GCTL1_ID_SHIFT;
1243 		write_c0_guestctl1(0);
1244 	}
1245 }
1246 
1247 static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c)
1248 {
1249 	/* determine the number of bits of GTOffset available */
1250 	write_c0_gtoffset(0xffffffff);
1251 	back_to_back_c0_hazard();
1252 	c->gtoffset_mask = read_c0_gtoffset();
1253 	write_c0_gtoffset(0);
1254 }
1255 
1256 static inline void cpu_probe_vz(struct cpuinfo_mips *c)
1257 {
1258 	cpu_probe_guestctl0(c);
1259 	if (cpu_has_guestctl1)
1260 		cpu_probe_guestctl1(c);
1261 
1262 	cpu_probe_gtoffset(c);
1263 
1264 	decode_guest_configs(c);
1265 }
1266 
1267 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
1268 		| MIPS_CPU_COUNTER)
1269 
1270 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
1271 {
1272 	switch (c->processor_id & PRID_IMP_MASK) {
1273 	case PRID_IMP_R2000:
1274 		c->cputype = CPU_R2000;
1275 		__cpu_name[cpu] = "R2000";
1276 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1277 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1278 			     MIPS_CPU_NOFPUEX;
1279 		if (__cpu_has_fpu())
1280 			c->options |= MIPS_CPU_FPU;
1281 		c->tlbsize = 64;
1282 		break;
1283 	case PRID_IMP_R3000:
1284 		if ((c->processor_id & PRID_REV_MASK) == PRID_REV_R3000A) {
1285 			if (cpu_has_confreg()) {
1286 				c->cputype = CPU_R3081E;
1287 				__cpu_name[cpu] = "R3081";
1288 			} else {
1289 				c->cputype = CPU_R3000A;
1290 				__cpu_name[cpu] = "R3000A";
1291 			}
1292 		} else {
1293 			c->cputype = CPU_R3000;
1294 			__cpu_name[cpu] = "R3000";
1295 		}
1296 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1297 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1298 			     MIPS_CPU_NOFPUEX;
1299 		if (__cpu_has_fpu())
1300 			c->options |= MIPS_CPU_FPU;
1301 		c->tlbsize = 64;
1302 		break;
1303 	case PRID_IMP_R4000:
1304 		if (read_c0_config() & CONF_SC) {
1305 			if ((c->processor_id & PRID_REV_MASK) >=
1306 			    PRID_REV_R4400) {
1307 				c->cputype = CPU_R4400PC;
1308 				__cpu_name[cpu] = "R4400PC";
1309 			} else {
1310 				c->cputype = CPU_R4000PC;
1311 				__cpu_name[cpu] = "R4000PC";
1312 			}
1313 		} else {
1314 			int cca = read_c0_config() & CONF_CM_CMASK;
1315 			int mc;
1316 
1317 			/*
1318 			 * SC and MC versions can't be reliably told apart,
1319 			 * but only the latter support coherent caching
1320 			 * modes so assume the firmware has set the KSEG0
1321 			 * coherency attribute reasonably (if uncached, we
1322 			 * assume SC).
1323 			 */
1324 			switch (cca) {
1325 			case CONF_CM_CACHABLE_CE:
1326 			case CONF_CM_CACHABLE_COW:
1327 			case CONF_CM_CACHABLE_CUW:
1328 				mc = 1;
1329 				break;
1330 			default:
1331 				mc = 0;
1332 				break;
1333 			}
1334 			if ((c->processor_id & PRID_REV_MASK) >=
1335 			    PRID_REV_R4400) {
1336 				c->cputype = mc ? CPU_R4400MC : CPU_R4400SC;
1337 				__cpu_name[cpu] = mc ? "R4400MC" : "R4400SC";
1338 			} else {
1339 				c->cputype = mc ? CPU_R4000MC : CPU_R4000SC;
1340 				__cpu_name[cpu] = mc ? "R4000MC" : "R4000SC";
1341 			}
1342 		}
1343 
1344 		set_isa(c, MIPS_CPU_ISA_III);
1345 		c->fpu_msk31 |= FPU_CSR_CONDX;
1346 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1347 			     MIPS_CPU_WATCH | MIPS_CPU_VCE |
1348 			     MIPS_CPU_LLSC;
1349 		c->tlbsize = 48;
1350 		break;
1351 	case PRID_IMP_VR41XX:
1352 		set_isa(c, MIPS_CPU_ISA_III);
1353 		c->fpu_msk31 |= FPU_CSR_CONDX;
1354 		c->options = R4K_OPTS;
1355 		c->tlbsize = 32;
1356 		switch (c->processor_id & 0xf0) {
1357 		case PRID_REV_VR4111:
1358 			c->cputype = CPU_VR4111;
1359 			__cpu_name[cpu] = "NEC VR4111";
1360 			break;
1361 		case PRID_REV_VR4121:
1362 			c->cputype = CPU_VR4121;
1363 			__cpu_name[cpu] = "NEC VR4121";
1364 			break;
1365 		case PRID_REV_VR4122:
1366 			if ((c->processor_id & 0xf) < 0x3) {
1367 				c->cputype = CPU_VR4122;
1368 				__cpu_name[cpu] = "NEC VR4122";
1369 			} else {
1370 				c->cputype = CPU_VR4181A;
1371 				__cpu_name[cpu] = "NEC VR4181A";
1372 			}
1373 			break;
1374 		case PRID_REV_VR4130:
1375 			if ((c->processor_id & 0xf) < 0x4) {
1376 				c->cputype = CPU_VR4131;
1377 				__cpu_name[cpu] = "NEC VR4131";
1378 			} else {
1379 				c->cputype = CPU_VR4133;
1380 				c->options |= MIPS_CPU_LLSC;
1381 				__cpu_name[cpu] = "NEC VR4133";
1382 			}
1383 			break;
1384 		default:
1385 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
1386 			c->cputype = CPU_VR41XX;
1387 			__cpu_name[cpu] = "NEC Vr41xx";
1388 			break;
1389 		}
1390 		break;
1391 	case PRID_IMP_R4300:
1392 		c->cputype = CPU_R4300;
1393 		__cpu_name[cpu] = "R4300";
1394 		set_isa(c, MIPS_CPU_ISA_III);
1395 		c->fpu_msk31 |= FPU_CSR_CONDX;
1396 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1397 			     MIPS_CPU_LLSC;
1398 		c->tlbsize = 32;
1399 		break;
1400 	case PRID_IMP_R4600:
1401 		c->cputype = CPU_R4600;
1402 		__cpu_name[cpu] = "R4600";
1403 		set_isa(c, MIPS_CPU_ISA_III);
1404 		c->fpu_msk31 |= FPU_CSR_CONDX;
1405 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1406 			     MIPS_CPU_LLSC;
1407 		c->tlbsize = 48;
1408 		break;
1409 	#if 0
1410 	case PRID_IMP_R4650:
1411 		/*
1412 		 * This processor doesn't have an MMU, so it's not
1413 		 * "real easy" to run Linux on it. It is left purely
1414 		 * for documentation.  Commented out because it shares
1415 		 * it's c0_prid id number with the TX3900.
1416 		 */
1417 		c->cputype = CPU_R4650;
1418 		__cpu_name[cpu] = "R4650";
1419 		set_isa(c, MIPS_CPU_ISA_III);
1420 		c->fpu_msk31 |= FPU_CSR_CONDX;
1421 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
1422 		c->tlbsize = 48;
1423 		break;
1424 	#endif
1425 	case PRID_IMP_TX39:
1426 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1427 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
1428 
1429 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
1430 			c->cputype = CPU_TX3927;
1431 			__cpu_name[cpu] = "TX3927";
1432 			c->tlbsize = 64;
1433 		} else {
1434 			switch (c->processor_id & PRID_REV_MASK) {
1435 			case PRID_REV_TX3912:
1436 				c->cputype = CPU_TX3912;
1437 				__cpu_name[cpu] = "TX3912";
1438 				c->tlbsize = 32;
1439 				break;
1440 			case PRID_REV_TX3922:
1441 				c->cputype = CPU_TX3922;
1442 				__cpu_name[cpu] = "TX3922";
1443 				c->tlbsize = 64;
1444 				break;
1445 			}
1446 		}
1447 		break;
1448 	case PRID_IMP_R4700:
1449 		c->cputype = CPU_R4700;
1450 		__cpu_name[cpu] = "R4700";
1451 		set_isa(c, MIPS_CPU_ISA_III);
1452 		c->fpu_msk31 |= FPU_CSR_CONDX;
1453 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1454 			     MIPS_CPU_LLSC;
1455 		c->tlbsize = 48;
1456 		break;
1457 	case PRID_IMP_TX49:
1458 		c->cputype = CPU_TX49XX;
1459 		__cpu_name[cpu] = "R49XX";
1460 		set_isa(c, MIPS_CPU_ISA_III);
1461 		c->fpu_msk31 |= FPU_CSR_CONDX;
1462 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
1463 		if (!(c->processor_id & 0x08))
1464 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
1465 		c->tlbsize = 48;
1466 		break;
1467 	case PRID_IMP_R5000:
1468 		c->cputype = CPU_R5000;
1469 		__cpu_name[cpu] = "R5000";
1470 		set_isa(c, MIPS_CPU_ISA_IV);
1471 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1472 			     MIPS_CPU_LLSC;
1473 		c->tlbsize = 48;
1474 		break;
1475 	case PRID_IMP_R5432:
1476 		c->cputype = CPU_R5432;
1477 		__cpu_name[cpu] = "R5432";
1478 		set_isa(c, MIPS_CPU_ISA_IV);
1479 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1480 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1481 		c->tlbsize = 48;
1482 		break;
1483 	case PRID_IMP_R5500:
1484 		c->cputype = CPU_R5500;
1485 		__cpu_name[cpu] = "R5500";
1486 		set_isa(c, MIPS_CPU_ISA_IV);
1487 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1488 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1489 		c->tlbsize = 48;
1490 		break;
1491 	case PRID_IMP_NEVADA:
1492 		c->cputype = CPU_NEVADA;
1493 		__cpu_name[cpu] = "Nevada";
1494 		set_isa(c, MIPS_CPU_ISA_IV);
1495 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1496 			     MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
1497 		c->tlbsize = 48;
1498 		break;
1499 	case PRID_IMP_RM7000:
1500 		c->cputype = CPU_RM7000;
1501 		__cpu_name[cpu] = "RM7000";
1502 		set_isa(c, MIPS_CPU_ISA_IV);
1503 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1504 			     MIPS_CPU_LLSC;
1505 		/*
1506 		 * Undocumented RM7000:	 Bit 29 in the info register of
1507 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
1508 		 * entries.
1509 		 *
1510 		 * 29	   1 =>	   64 entry JTLB
1511 		 *	   0 =>	   48 entry JTLB
1512 		 */
1513 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
1514 		break;
1515 	case PRID_IMP_R8000:
1516 		c->cputype = CPU_R8000;
1517 		__cpu_name[cpu] = "RM8000";
1518 		set_isa(c, MIPS_CPU_ISA_IV);
1519 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
1520 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1521 			     MIPS_CPU_LLSC;
1522 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
1523 		break;
1524 	case PRID_IMP_R10000:
1525 		c->cputype = CPU_R10000;
1526 		__cpu_name[cpu] = "R10000";
1527 		set_isa(c, MIPS_CPU_ISA_IV);
1528 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1529 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1530 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1531 			     MIPS_CPU_LLSC;
1532 		c->tlbsize = 64;
1533 		break;
1534 	case PRID_IMP_R12000:
1535 		c->cputype = CPU_R12000;
1536 		__cpu_name[cpu] = "R12000";
1537 		set_isa(c, MIPS_CPU_ISA_IV);
1538 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1539 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1540 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1541 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1542 		c->tlbsize = 64;
1543 		break;
1544 	case PRID_IMP_R14000:
1545 		if (((c->processor_id >> 4) & 0x0f) > 2) {
1546 			c->cputype = CPU_R16000;
1547 			__cpu_name[cpu] = "R16000";
1548 		} else {
1549 			c->cputype = CPU_R14000;
1550 			__cpu_name[cpu] = "R14000";
1551 		}
1552 		set_isa(c, MIPS_CPU_ISA_IV);
1553 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1554 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1555 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1556 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1557 		c->tlbsize = 64;
1558 		break;
1559 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1560 		switch (c->processor_id & PRID_REV_MASK) {
1561 		case PRID_REV_LOONGSON2E:
1562 			c->cputype = CPU_LOONGSON2;
1563 			__cpu_name[cpu] = "ICT Loongson-2";
1564 			set_elf_platform(cpu, "loongson2e");
1565 			set_isa(c, MIPS_CPU_ISA_III);
1566 			c->fpu_msk31 |= FPU_CSR_CONDX;
1567 			break;
1568 		case PRID_REV_LOONGSON2F:
1569 			c->cputype = CPU_LOONGSON2;
1570 			__cpu_name[cpu] = "ICT Loongson-2";
1571 			set_elf_platform(cpu, "loongson2f");
1572 			set_isa(c, MIPS_CPU_ISA_III);
1573 			c->fpu_msk31 |= FPU_CSR_CONDX;
1574 			break;
1575 		case PRID_REV_LOONGSON3A_R1:
1576 			c->cputype = CPU_LOONGSON3;
1577 			__cpu_name[cpu] = "ICT Loongson-3";
1578 			set_elf_platform(cpu, "loongson3a");
1579 			set_isa(c, MIPS_CPU_ISA_M64R1);
1580 			break;
1581 		case PRID_REV_LOONGSON3B_R1:
1582 		case PRID_REV_LOONGSON3B_R2:
1583 			c->cputype = CPU_LOONGSON3;
1584 			__cpu_name[cpu] = "ICT Loongson-3";
1585 			set_elf_platform(cpu, "loongson3b");
1586 			set_isa(c, MIPS_CPU_ISA_M64R1);
1587 			break;
1588 		}
1589 
1590 		c->options = R4K_OPTS |
1591 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
1592 			     MIPS_CPU_32FPR;
1593 		c->tlbsize = 64;
1594 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1595 		break;
1596 	case PRID_IMP_LOONGSON_32:  /* Loongson-1 */
1597 		decode_configs(c);
1598 
1599 		c->cputype = CPU_LOONGSON1;
1600 
1601 		switch (c->processor_id & PRID_REV_MASK) {
1602 		case PRID_REV_LOONGSON1B:
1603 			__cpu_name[cpu] = "Loongson 1B";
1604 			break;
1605 		}
1606 
1607 		break;
1608 	}
1609 }
1610 
1611 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
1612 {
1613 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1614 	switch (c->processor_id & PRID_IMP_MASK) {
1615 	case PRID_IMP_QEMU_GENERIC:
1616 		c->writecombine = _CACHE_UNCACHED;
1617 		c->cputype = CPU_QEMU_GENERIC;
1618 		__cpu_name[cpu] = "MIPS GENERIC QEMU";
1619 		break;
1620 	case PRID_IMP_4KC:
1621 		c->cputype = CPU_4KC;
1622 		c->writecombine = _CACHE_UNCACHED;
1623 		__cpu_name[cpu] = "MIPS 4Kc";
1624 		break;
1625 	case PRID_IMP_4KEC:
1626 	case PRID_IMP_4KECR2:
1627 		c->cputype = CPU_4KEC;
1628 		c->writecombine = _CACHE_UNCACHED;
1629 		__cpu_name[cpu] = "MIPS 4KEc";
1630 		break;
1631 	case PRID_IMP_4KSC:
1632 	case PRID_IMP_4KSD:
1633 		c->cputype = CPU_4KSC;
1634 		c->writecombine = _CACHE_UNCACHED;
1635 		__cpu_name[cpu] = "MIPS 4KSc";
1636 		break;
1637 	case PRID_IMP_5KC:
1638 		c->cputype = CPU_5KC;
1639 		c->writecombine = _CACHE_UNCACHED;
1640 		__cpu_name[cpu] = "MIPS 5Kc";
1641 		break;
1642 	case PRID_IMP_5KE:
1643 		c->cputype = CPU_5KE;
1644 		c->writecombine = _CACHE_UNCACHED;
1645 		__cpu_name[cpu] = "MIPS 5KE";
1646 		break;
1647 	case PRID_IMP_20KC:
1648 		c->cputype = CPU_20KC;
1649 		c->writecombine = _CACHE_UNCACHED;
1650 		__cpu_name[cpu] = "MIPS 20Kc";
1651 		break;
1652 	case PRID_IMP_24K:
1653 		c->cputype = CPU_24K;
1654 		c->writecombine = _CACHE_UNCACHED;
1655 		__cpu_name[cpu] = "MIPS 24Kc";
1656 		break;
1657 	case PRID_IMP_24KE:
1658 		c->cputype = CPU_24K;
1659 		c->writecombine = _CACHE_UNCACHED;
1660 		__cpu_name[cpu] = "MIPS 24KEc";
1661 		break;
1662 	case PRID_IMP_25KF:
1663 		c->cputype = CPU_25KF;
1664 		c->writecombine = _CACHE_UNCACHED;
1665 		__cpu_name[cpu] = "MIPS 25Kc";
1666 		break;
1667 	case PRID_IMP_34K:
1668 		c->cputype = CPU_34K;
1669 		c->writecombine = _CACHE_UNCACHED;
1670 		__cpu_name[cpu] = "MIPS 34Kc";
1671 		cpu_set_mt_per_tc_perf(c);
1672 		break;
1673 	case PRID_IMP_74K:
1674 		c->cputype = CPU_74K;
1675 		c->writecombine = _CACHE_UNCACHED;
1676 		__cpu_name[cpu] = "MIPS 74Kc";
1677 		break;
1678 	case PRID_IMP_M14KC:
1679 		c->cputype = CPU_M14KC;
1680 		c->writecombine = _CACHE_UNCACHED;
1681 		__cpu_name[cpu] = "MIPS M14Kc";
1682 		break;
1683 	case PRID_IMP_M14KEC:
1684 		c->cputype = CPU_M14KEC;
1685 		c->writecombine = _CACHE_UNCACHED;
1686 		__cpu_name[cpu] = "MIPS M14KEc";
1687 		break;
1688 	case PRID_IMP_1004K:
1689 		c->cputype = CPU_1004K;
1690 		c->writecombine = _CACHE_UNCACHED;
1691 		__cpu_name[cpu] = "MIPS 1004Kc";
1692 		cpu_set_mt_per_tc_perf(c);
1693 		break;
1694 	case PRID_IMP_1074K:
1695 		c->cputype = CPU_1074K;
1696 		c->writecombine = _CACHE_UNCACHED;
1697 		__cpu_name[cpu] = "MIPS 1074Kc";
1698 		break;
1699 	case PRID_IMP_INTERAPTIV_UP:
1700 		c->cputype = CPU_INTERAPTIV;
1701 		__cpu_name[cpu] = "MIPS interAptiv";
1702 		cpu_set_mt_per_tc_perf(c);
1703 		break;
1704 	case PRID_IMP_INTERAPTIV_MP:
1705 		c->cputype = CPU_INTERAPTIV;
1706 		__cpu_name[cpu] = "MIPS interAptiv (multi)";
1707 		cpu_set_mt_per_tc_perf(c);
1708 		break;
1709 	case PRID_IMP_PROAPTIV_UP:
1710 		c->cputype = CPU_PROAPTIV;
1711 		__cpu_name[cpu] = "MIPS proAptiv";
1712 		break;
1713 	case PRID_IMP_PROAPTIV_MP:
1714 		c->cputype = CPU_PROAPTIV;
1715 		__cpu_name[cpu] = "MIPS proAptiv (multi)";
1716 		break;
1717 	case PRID_IMP_P5600:
1718 		c->cputype = CPU_P5600;
1719 		__cpu_name[cpu] = "MIPS P5600";
1720 		break;
1721 	case PRID_IMP_P6600:
1722 		c->cputype = CPU_P6600;
1723 		__cpu_name[cpu] = "MIPS P6600";
1724 		break;
1725 	case PRID_IMP_I6400:
1726 		c->cputype = CPU_I6400;
1727 		__cpu_name[cpu] = "MIPS I6400";
1728 		break;
1729 	case PRID_IMP_I6500:
1730 		c->cputype = CPU_I6500;
1731 		__cpu_name[cpu] = "MIPS I6500";
1732 		break;
1733 	case PRID_IMP_M5150:
1734 		c->cputype = CPU_M5150;
1735 		__cpu_name[cpu] = "MIPS M5150";
1736 		break;
1737 	case PRID_IMP_M6250:
1738 		c->cputype = CPU_M6250;
1739 		__cpu_name[cpu] = "MIPS M6250";
1740 		break;
1741 	}
1742 
1743 	decode_configs(c);
1744 
1745 	spram_config();
1746 
1747 	switch (__get_cpu_type(c->cputype)) {
1748 	case CPU_I6500:
1749 		c->options |= MIPS_CPU_SHARED_FTLB_ENTRIES;
1750 		/* fall-through */
1751 	case CPU_I6400:
1752 		c->options |= MIPS_CPU_SHARED_FTLB_RAM;
1753 		/* fall-through */
1754 	default:
1755 		break;
1756 	}
1757 }
1758 
1759 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
1760 {
1761 	decode_configs(c);
1762 	switch (c->processor_id & PRID_IMP_MASK) {
1763 	case PRID_IMP_AU1_REV1:
1764 	case PRID_IMP_AU1_REV2:
1765 		c->cputype = CPU_ALCHEMY;
1766 		switch ((c->processor_id >> 24) & 0xff) {
1767 		case 0:
1768 			__cpu_name[cpu] = "Au1000";
1769 			break;
1770 		case 1:
1771 			__cpu_name[cpu] = "Au1500";
1772 			break;
1773 		case 2:
1774 			__cpu_name[cpu] = "Au1100";
1775 			break;
1776 		case 3:
1777 			__cpu_name[cpu] = "Au1550";
1778 			break;
1779 		case 4:
1780 			__cpu_name[cpu] = "Au1200";
1781 			if ((c->processor_id & PRID_REV_MASK) == 2)
1782 				__cpu_name[cpu] = "Au1250";
1783 			break;
1784 		case 5:
1785 			__cpu_name[cpu] = "Au1210";
1786 			break;
1787 		default:
1788 			__cpu_name[cpu] = "Au1xxx";
1789 			break;
1790 		}
1791 		break;
1792 	}
1793 }
1794 
1795 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
1796 {
1797 	decode_configs(c);
1798 
1799 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1800 	switch (c->processor_id & PRID_IMP_MASK) {
1801 	case PRID_IMP_SB1:
1802 		c->cputype = CPU_SB1;
1803 		__cpu_name[cpu] = "SiByte SB1";
1804 		/* FPU in pass1 is known to have issues. */
1805 		if ((c->processor_id & PRID_REV_MASK) < 0x02)
1806 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
1807 		break;
1808 	case PRID_IMP_SB1A:
1809 		c->cputype = CPU_SB1A;
1810 		__cpu_name[cpu] = "SiByte SB1A";
1811 		break;
1812 	}
1813 }
1814 
1815 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
1816 {
1817 	decode_configs(c);
1818 	switch (c->processor_id & PRID_IMP_MASK) {
1819 	case PRID_IMP_SR71000:
1820 		c->cputype = CPU_SR71000;
1821 		__cpu_name[cpu] = "Sandcraft SR71000";
1822 		c->scache.ways = 8;
1823 		c->tlbsize = 64;
1824 		break;
1825 	}
1826 }
1827 
1828 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
1829 {
1830 	decode_configs(c);
1831 	switch (c->processor_id & PRID_IMP_MASK) {
1832 	case PRID_IMP_PR4450:
1833 		c->cputype = CPU_PR4450;
1834 		__cpu_name[cpu] = "Philips PR4450";
1835 		set_isa(c, MIPS_CPU_ISA_M32R1);
1836 		break;
1837 	}
1838 }
1839 
1840 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
1841 {
1842 	decode_configs(c);
1843 	switch (c->processor_id & PRID_IMP_MASK) {
1844 	case PRID_IMP_BMIPS32_REV4:
1845 	case PRID_IMP_BMIPS32_REV8:
1846 		c->cputype = CPU_BMIPS32;
1847 		__cpu_name[cpu] = "Broadcom BMIPS32";
1848 		set_elf_platform(cpu, "bmips32");
1849 		break;
1850 	case PRID_IMP_BMIPS3300:
1851 	case PRID_IMP_BMIPS3300_ALT:
1852 	case PRID_IMP_BMIPS3300_BUG:
1853 		c->cputype = CPU_BMIPS3300;
1854 		__cpu_name[cpu] = "Broadcom BMIPS3300";
1855 		set_elf_platform(cpu, "bmips3300");
1856 		break;
1857 	case PRID_IMP_BMIPS43XX: {
1858 		int rev = c->processor_id & PRID_REV_MASK;
1859 
1860 		if (rev >= PRID_REV_BMIPS4380_LO &&
1861 				rev <= PRID_REV_BMIPS4380_HI) {
1862 			c->cputype = CPU_BMIPS4380;
1863 			__cpu_name[cpu] = "Broadcom BMIPS4380";
1864 			set_elf_platform(cpu, "bmips4380");
1865 			c->options |= MIPS_CPU_RIXI;
1866 		} else {
1867 			c->cputype = CPU_BMIPS4350;
1868 			__cpu_name[cpu] = "Broadcom BMIPS4350";
1869 			set_elf_platform(cpu, "bmips4350");
1870 		}
1871 		break;
1872 	}
1873 	case PRID_IMP_BMIPS5000:
1874 	case PRID_IMP_BMIPS5200:
1875 		c->cputype = CPU_BMIPS5000;
1876 		if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_BMIPS5200)
1877 			__cpu_name[cpu] = "Broadcom BMIPS5200";
1878 		else
1879 			__cpu_name[cpu] = "Broadcom BMIPS5000";
1880 		set_elf_platform(cpu, "bmips5000");
1881 		c->options |= MIPS_CPU_ULRI | MIPS_CPU_RIXI;
1882 		break;
1883 	}
1884 }
1885 
1886 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
1887 {
1888 	decode_configs(c);
1889 	switch (c->processor_id & PRID_IMP_MASK) {
1890 	case PRID_IMP_CAVIUM_CN38XX:
1891 	case PRID_IMP_CAVIUM_CN31XX:
1892 	case PRID_IMP_CAVIUM_CN30XX:
1893 		c->cputype = CPU_CAVIUM_OCTEON;
1894 		__cpu_name[cpu] = "Cavium Octeon";
1895 		goto platform;
1896 	case PRID_IMP_CAVIUM_CN58XX:
1897 	case PRID_IMP_CAVIUM_CN56XX:
1898 	case PRID_IMP_CAVIUM_CN50XX:
1899 	case PRID_IMP_CAVIUM_CN52XX:
1900 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
1901 		__cpu_name[cpu] = "Cavium Octeon+";
1902 platform:
1903 		set_elf_platform(cpu, "octeon");
1904 		break;
1905 	case PRID_IMP_CAVIUM_CN61XX:
1906 	case PRID_IMP_CAVIUM_CN63XX:
1907 	case PRID_IMP_CAVIUM_CN66XX:
1908 	case PRID_IMP_CAVIUM_CN68XX:
1909 	case PRID_IMP_CAVIUM_CNF71XX:
1910 		c->cputype = CPU_CAVIUM_OCTEON2;
1911 		__cpu_name[cpu] = "Cavium Octeon II";
1912 		set_elf_platform(cpu, "octeon2");
1913 		break;
1914 	case PRID_IMP_CAVIUM_CN70XX:
1915 	case PRID_IMP_CAVIUM_CN73XX:
1916 	case PRID_IMP_CAVIUM_CNF75XX:
1917 	case PRID_IMP_CAVIUM_CN78XX:
1918 		c->cputype = CPU_CAVIUM_OCTEON3;
1919 		__cpu_name[cpu] = "Cavium Octeon III";
1920 		set_elf_platform(cpu, "octeon3");
1921 		break;
1922 	default:
1923 		printk(KERN_INFO "Unknown Octeon chip!\n");
1924 		c->cputype = CPU_UNKNOWN;
1925 		break;
1926 	}
1927 }
1928 
1929 static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
1930 {
1931 	switch (c->processor_id & PRID_IMP_MASK) {
1932 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1933 		switch (c->processor_id & PRID_REV_MASK) {
1934 		case PRID_REV_LOONGSON3A_R2_0:
1935 		case PRID_REV_LOONGSON3A_R2_1:
1936 			c->cputype = CPU_LOONGSON3;
1937 			__cpu_name[cpu] = "ICT Loongson-3";
1938 			set_elf_platform(cpu, "loongson3a");
1939 			set_isa(c, MIPS_CPU_ISA_M64R2);
1940 			break;
1941 		case PRID_REV_LOONGSON3A_R3_0:
1942 		case PRID_REV_LOONGSON3A_R3_1:
1943 			c->cputype = CPU_LOONGSON3;
1944 			__cpu_name[cpu] = "ICT Loongson-3";
1945 			set_elf_platform(cpu, "loongson3a");
1946 			set_isa(c, MIPS_CPU_ISA_M64R2);
1947 			break;
1948 		}
1949 
1950 		decode_configs(c);
1951 		c->options |= MIPS_CPU_FTLB | MIPS_CPU_TLBINV | MIPS_CPU_LDPTE;
1952 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1953 		break;
1954 	default:
1955 		panic("Unknown Loongson Processor ID!");
1956 		break;
1957 	}
1958 }
1959 
1960 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
1961 {
1962 	decode_configs(c);
1963 	/* JZRISC does not implement the CP0 counter. */
1964 	c->options &= ~MIPS_CPU_COUNTER;
1965 	BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);
1966 	switch (c->processor_id & PRID_IMP_MASK) {
1967 	case PRID_IMP_JZRISC:
1968 		c->cputype = CPU_JZRISC;
1969 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1970 		__cpu_name[cpu] = "Ingenic JZRISC";
1971 		break;
1972 	default:
1973 		panic("Unknown Ingenic Processor ID!");
1974 		break;
1975 	}
1976 }
1977 
1978 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1979 {
1980 	decode_configs(c);
1981 
1982 	if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_NETLOGIC_AU13XX) {
1983 		c->cputype = CPU_ALCHEMY;
1984 		__cpu_name[cpu] = "Au1300";
1985 		/* following stuff is not for Alchemy */
1986 		return;
1987 	}
1988 
1989 	c->options = (MIPS_CPU_TLB	 |
1990 			MIPS_CPU_4KEX	 |
1991 			MIPS_CPU_COUNTER |
1992 			MIPS_CPU_DIVEC	 |
1993 			MIPS_CPU_WATCH	 |
1994 			MIPS_CPU_EJTAG	 |
1995 			MIPS_CPU_LLSC);
1996 
1997 	switch (c->processor_id & PRID_IMP_MASK) {
1998 	case PRID_IMP_NETLOGIC_XLP2XX:
1999 	case PRID_IMP_NETLOGIC_XLP9XX:
2000 	case PRID_IMP_NETLOGIC_XLP5XX:
2001 		c->cputype = CPU_XLP;
2002 		__cpu_name[cpu] = "Broadcom XLPII";
2003 		break;
2004 
2005 	case PRID_IMP_NETLOGIC_XLP8XX:
2006 	case PRID_IMP_NETLOGIC_XLP3XX:
2007 		c->cputype = CPU_XLP;
2008 		__cpu_name[cpu] = "Netlogic XLP";
2009 		break;
2010 
2011 	case PRID_IMP_NETLOGIC_XLR732:
2012 	case PRID_IMP_NETLOGIC_XLR716:
2013 	case PRID_IMP_NETLOGIC_XLR532:
2014 	case PRID_IMP_NETLOGIC_XLR308:
2015 	case PRID_IMP_NETLOGIC_XLR532C:
2016 	case PRID_IMP_NETLOGIC_XLR516C:
2017 	case PRID_IMP_NETLOGIC_XLR508C:
2018 	case PRID_IMP_NETLOGIC_XLR308C:
2019 		c->cputype = CPU_XLR;
2020 		__cpu_name[cpu] = "Netlogic XLR";
2021 		break;
2022 
2023 	case PRID_IMP_NETLOGIC_XLS608:
2024 	case PRID_IMP_NETLOGIC_XLS408:
2025 	case PRID_IMP_NETLOGIC_XLS404:
2026 	case PRID_IMP_NETLOGIC_XLS208:
2027 	case PRID_IMP_NETLOGIC_XLS204:
2028 	case PRID_IMP_NETLOGIC_XLS108:
2029 	case PRID_IMP_NETLOGIC_XLS104:
2030 	case PRID_IMP_NETLOGIC_XLS616B:
2031 	case PRID_IMP_NETLOGIC_XLS608B:
2032 	case PRID_IMP_NETLOGIC_XLS416B:
2033 	case PRID_IMP_NETLOGIC_XLS412B:
2034 	case PRID_IMP_NETLOGIC_XLS408B:
2035 	case PRID_IMP_NETLOGIC_XLS404B:
2036 		c->cputype = CPU_XLR;
2037 		__cpu_name[cpu] = "Netlogic XLS";
2038 		break;
2039 
2040 	default:
2041 		pr_info("Unknown Netlogic chip id [%02x]!\n",
2042 		       c->processor_id);
2043 		c->cputype = CPU_XLR;
2044 		break;
2045 	}
2046 
2047 	if (c->cputype == CPU_XLP) {
2048 		set_isa(c, MIPS_CPU_ISA_M64R2);
2049 		c->options |= (MIPS_CPU_FPU | MIPS_CPU_ULRI | MIPS_CPU_MCHECK);
2050 		/* This will be updated again after all threads are woken up */
2051 		c->tlbsize = ((read_c0_config6() >> 16) & 0xffff) + 1;
2052 	} else {
2053 		set_isa(c, MIPS_CPU_ISA_M64R1);
2054 		c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
2055 	}
2056 	c->kscratch_mask = 0xf;
2057 }
2058 
2059 #ifdef CONFIG_64BIT
2060 /* For use by uaccess.h */
2061 u64 __ua_limit;
2062 EXPORT_SYMBOL(__ua_limit);
2063 #endif
2064 
2065 const char *__cpu_name[NR_CPUS];
2066 const char *__elf_platform;
2067 
2068 void cpu_probe(void)
2069 {
2070 	struct cpuinfo_mips *c = &current_cpu_data;
2071 	unsigned int cpu = smp_processor_id();
2072 
2073 	/*
2074 	 * Set a default elf platform, cpu probe may later
2075 	 * overwrite it with a more precise value
2076 	 */
2077 	set_elf_platform(cpu, "mips");
2078 
2079 	c->processor_id = PRID_IMP_UNKNOWN;
2080 	c->fpu_id	= FPIR_IMP_NONE;
2081 	c->cputype	= CPU_UNKNOWN;
2082 	c->writecombine = _CACHE_UNCACHED;
2083 
2084 	c->fpu_csr31	= FPU_CSR_RN;
2085 	c->fpu_msk31	= FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
2086 
2087 	c->processor_id = read_c0_prid();
2088 	switch (c->processor_id & PRID_COMP_MASK) {
2089 	case PRID_COMP_LEGACY:
2090 		cpu_probe_legacy(c, cpu);
2091 		break;
2092 	case PRID_COMP_MIPS:
2093 		cpu_probe_mips(c, cpu);
2094 		break;
2095 	case PRID_COMP_ALCHEMY:
2096 		cpu_probe_alchemy(c, cpu);
2097 		break;
2098 	case PRID_COMP_SIBYTE:
2099 		cpu_probe_sibyte(c, cpu);
2100 		break;
2101 	case PRID_COMP_BROADCOM:
2102 		cpu_probe_broadcom(c, cpu);
2103 		break;
2104 	case PRID_COMP_SANDCRAFT:
2105 		cpu_probe_sandcraft(c, cpu);
2106 		break;
2107 	case PRID_COMP_NXP:
2108 		cpu_probe_nxp(c, cpu);
2109 		break;
2110 	case PRID_COMP_CAVIUM:
2111 		cpu_probe_cavium(c, cpu);
2112 		break;
2113 	case PRID_COMP_LOONGSON:
2114 		cpu_probe_loongson(c, cpu);
2115 		break;
2116 	case PRID_COMP_INGENIC_D0:
2117 	case PRID_COMP_INGENIC_D1:
2118 	case PRID_COMP_INGENIC_E1:
2119 		cpu_probe_ingenic(c, cpu);
2120 		break;
2121 	case PRID_COMP_NETLOGIC:
2122 		cpu_probe_netlogic(c, cpu);
2123 		break;
2124 	}
2125 
2126 	BUG_ON(!__cpu_name[cpu]);
2127 	BUG_ON(c->cputype == CPU_UNKNOWN);
2128 
2129 	/*
2130 	 * Platform code can force the cpu type to optimize code
2131 	 * generation. In that case be sure the cpu type is correctly
2132 	 * manually setup otherwise it could trigger some nasty bugs.
2133 	 */
2134 	BUG_ON(current_cpu_type() != c->cputype);
2135 
2136 	if (cpu_has_rixi) {
2137 		/* Enable the RIXI exceptions */
2138 		set_c0_pagegrain(PG_IEC);
2139 		back_to_back_c0_hazard();
2140 		/* Verify the IEC bit is set */
2141 		if (read_c0_pagegrain() & PG_IEC)
2142 			c->options |= MIPS_CPU_RIXIEX;
2143 	}
2144 
2145 	if (mips_fpu_disabled)
2146 		c->options &= ~MIPS_CPU_FPU;
2147 
2148 	if (mips_dsp_disabled)
2149 		c->ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
2150 
2151 	if (mips_htw_disabled) {
2152 		c->options &= ~MIPS_CPU_HTW;
2153 		write_c0_pwctl(read_c0_pwctl() &
2154 			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
2155 	}
2156 
2157 	if (c->options & MIPS_CPU_FPU)
2158 		cpu_set_fpu_opts(c);
2159 	else
2160 		cpu_set_nofpu_opts(c);
2161 
2162 	if (cpu_has_bp_ghist)
2163 		write_c0_r10k_diag(read_c0_r10k_diag() |
2164 				   R10K_DIAG_E_GHIST);
2165 
2166 	if (cpu_has_mips_r2_r6) {
2167 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
2168 		/* R2 has Performance Counter Interrupt indicator */
2169 		c->options |= MIPS_CPU_PCI;
2170 	}
2171 	else
2172 		c->srsets = 1;
2173 
2174 	if (cpu_has_mips_r6)
2175 		elf_hwcap |= HWCAP_MIPS_R6;
2176 
2177 	if (cpu_has_msa) {
2178 		c->msa_id = cpu_get_msa_id();
2179 		WARN(c->msa_id & MSA_IR_WRPF,
2180 		     "Vector register partitioning unimplemented!");
2181 		elf_hwcap |= HWCAP_MIPS_MSA;
2182 	}
2183 
2184 	if (cpu_has_vz)
2185 		cpu_probe_vz(c);
2186 
2187 	cpu_probe_vmbits(c);
2188 
2189 #ifdef CONFIG_64BIT
2190 	if (cpu == 0)
2191 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
2192 #endif
2193 }
2194 
2195 void cpu_report(void)
2196 {
2197 	struct cpuinfo_mips *c = &current_cpu_data;
2198 
2199 	pr_info("CPU%d revision is: %08x (%s)\n",
2200 		smp_processor_id(), c->processor_id, cpu_name_string());
2201 	if (c->options & MIPS_CPU_FPU)
2202 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
2203 	if (cpu_has_msa)
2204 		pr_info("MSA revision is: %08x\n", c->msa_id);
2205 }
2206 
2207 void cpu_set_cluster(struct cpuinfo_mips *cpuinfo, unsigned int cluster)
2208 {
2209 	/* Ensure the core number fits in the field */
2210 	WARN_ON(cluster > (MIPS_GLOBALNUMBER_CLUSTER >>
2211 			   MIPS_GLOBALNUMBER_CLUSTER_SHF));
2212 
2213 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_CLUSTER;
2214 	cpuinfo->globalnumber |= cluster << MIPS_GLOBALNUMBER_CLUSTER_SHF;
2215 }
2216 
2217 void cpu_set_core(struct cpuinfo_mips *cpuinfo, unsigned int core)
2218 {
2219 	/* Ensure the core number fits in the field */
2220 	WARN_ON(core > (MIPS_GLOBALNUMBER_CORE >> MIPS_GLOBALNUMBER_CORE_SHF));
2221 
2222 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_CORE;
2223 	cpuinfo->globalnumber |= core << MIPS_GLOBALNUMBER_CORE_SHF;
2224 }
2225 
2226 void cpu_set_vpe_id(struct cpuinfo_mips *cpuinfo, unsigned int vpe)
2227 {
2228 	/* Ensure the VP(E) ID fits in the field */
2229 	WARN_ON(vpe > (MIPS_GLOBALNUMBER_VP >> MIPS_GLOBALNUMBER_VP_SHF));
2230 
2231 	/* Ensure we're not using VP(E)s without support */
2232 	WARN_ON(vpe && !IS_ENABLED(CONFIG_MIPS_MT_SMP) &&
2233 		!IS_ENABLED(CONFIG_CPU_MIPSR6));
2234 
2235 	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_VP;
2236 	cpuinfo->globalnumber |= vpe << MIPS_GLOBALNUMBER_VP_SHF;
2237 }
2238