xref: /linux/arch/mips/kernel/cpu-probe.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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 <asm/uaccess.h>
34 
35 /* Hardware capabilities */
36 unsigned int elf_hwcap __read_mostly;
37 
38 /*
39  * Get the FPU Implementation/Revision.
40  */
41 static inline unsigned long cpu_get_fpu_id(void)
42 {
43 	unsigned long tmp, fpu_id;
44 
45 	tmp = read_c0_status();
46 	__enable_fpu(FPU_AS_IS);
47 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
48 	write_c0_status(tmp);
49 	return fpu_id;
50 }
51 
52 /*
53  * Check if the CPU has an external FPU.
54  */
55 static inline int __cpu_has_fpu(void)
56 {
57 	return (cpu_get_fpu_id() & FPIR_IMP_MASK) != FPIR_IMP_NONE;
58 }
59 
60 static inline unsigned long cpu_get_msa_id(void)
61 {
62 	unsigned long status, msa_id;
63 
64 	status = read_c0_status();
65 	__enable_fpu(FPU_64BIT);
66 	enable_msa();
67 	msa_id = read_msa_ir();
68 	disable_msa();
69 	write_c0_status(status);
70 	return msa_id;
71 }
72 
73 /*
74  * Determine the FCSR mask for FPU hardware.
75  */
76 static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_mips *c)
77 {
78 	unsigned long sr, mask, fcsr, fcsr0, fcsr1;
79 
80 	fcsr = c->fpu_csr31;
81 	mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM;
82 
83 	sr = read_c0_status();
84 	__enable_fpu(FPU_AS_IS);
85 
86 	fcsr0 = fcsr & mask;
87 	write_32bit_cp1_register(CP1_STATUS, fcsr0);
88 	fcsr0 = read_32bit_cp1_register(CP1_STATUS);
89 
90 	fcsr1 = fcsr | ~mask;
91 	write_32bit_cp1_register(CP1_STATUS, fcsr1);
92 	fcsr1 = read_32bit_cp1_register(CP1_STATUS);
93 
94 	write_32bit_cp1_register(CP1_STATUS, fcsr);
95 
96 	write_c0_status(sr);
97 
98 	c->fpu_msk31 = ~(fcsr0 ^ fcsr1) & ~mask;
99 }
100 
101 /*
102  * Determine the IEEE 754 NaN encodings and ABS.fmt/NEG.fmt execution modes
103  * supported by FPU hardware.
104  */
105 static void cpu_set_fpu_2008(struct cpuinfo_mips *c)
106 {
107 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
108 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
109 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
110 		unsigned long sr, fir, fcsr, fcsr0, fcsr1;
111 
112 		sr = read_c0_status();
113 		__enable_fpu(FPU_AS_IS);
114 
115 		fir = read_32bit_cp1_register(CP1_REVISION);
116 		if (fir & MIPS_FPIR_HAS2008) {
117 			fcsr = read_32bit_cp1_register(CP1_STATUS);
118 
119 			fcsr0 = fcsr & ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
120 			write_32bit_cp1_register(CP1_STATUS, fcsr0);
121 			fcsr0 = read_32bit_cp1_register(CP1_STATUS);
122 
123 			fcsr1 = fcsr | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
124 			write_32bit_cp1_register(CP1_STATUS, fcsr1);
125 			fcsr1 = read_32bit_cp1_register(CP1_STATUS);
126 
127 			write_32bit_cp1_register(CP1_STATUS, fcsr);
128 
129 			if (!(fcsr0 & FPU_CSR_NAN2008))
130 				c->options |= MIPS_CPU_NAN_LEGACY;
131 			if (fcsr1 & FPU_CSR_NAN2008)
132 				c->options |= MIPS_CPU_NAN_2008;
133 
134 			if ((fcsr0 ^ fcsr1) & FPU_CSR_ABS2008)
135 				c->fpu_msk31 &= ~FPU_CSR_ABS2008;
136 			else
137 				c->fpu_csr31 |= fcsr & FPU_CSR_ABS2008;
138 
139 			if ((fcsr0 ^ fcsr1) & FPU_CSR_NAN2008)
140 				c->fpu_msk31 &= ~FPU_CSR_NAN2008;
141 			else
142 				c->fpu_csr31 |= fcsr & FPU_CSR_NAN2008;
143 		} else {
144 			c->options |= MIPS_CPU_NAN_LEGACY;
145 		}
146 
147 		write_c0_status(sr);
148 	} else {
149 		c->options |= MIPS_CPU_NAN_LEGACY;
150 	}
151 }
152 
153 /*
154  * IEEE 754 conformance mode to use.  Affects the NaN encoding and the
155  * ABS.fmt/NEG.fmt execution mode.
156  */
157 static enum { STRICT, LEGACY, STD2008, RELAXED } ieee754 = STRICT;
158 
159 /*
160  * Set the IEEE 754 NaN encodings and the ABS.fmt/NEG.fmt execution modes
161  * to support by the FPU emulator according to the IEEE 754 conformance
162  * mode selected.  Note that "relaxed" straps the emulator so that it
163  * allows 2008-NaN binaries even for legacy processors.
164  */
165 static void cpu_set_nofpu_2008(struct cpuinfo_mips *c)
166 {
167 	c->options &= ~(MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY);
168 	c->fpu_csr31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
169 	c->fpu_msk31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
170 
171 	switch (ieee754) {
172 	case STRICT:
173 		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
174 				    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
175 				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
176 			c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
177 		} else {
178 			c->options |= MIPS_CPU_NAN_LEGACY;
179 			c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
180 		}
181 		break;
182 	case LEGACY:
183 		c->options |= MIPS_CPU_NAN_LEGACY;
184 		c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
185 		break;
186 	case STD2008:
187 		c->options |= MIPS_CPU_NAN_2008;
188 		c->fpu_csr31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
189 		c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
190 		break;
191 	case RELAXED:
192 		c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
193 		break;
194 	}
195 }
196 
197 /*
198  * Override the IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode
199  * according to the "ieee754=" parameter.
200  */
201 static void cpu_set_nan_2008(struct cpuinfo_mips *c)
202 {
203 	switch (ieee754) {
204 	case STRICT:
205 		mips_use_nan_legacy = !!cpu_has_nan_legacy;
206 		mips_use_nan_2008 = !!cpu_has_nan_2008;
207 		break;
208 	case LEGACY:
209 		mips_use_nan_legacy = !!cpu_has_nan_legacy;
210 		mips_use_nan_2008 = !cpu_has_nan_legacy;
211 		break;
212 	case STD2008:
213 		mips_use_nan_legacy = !cpu_has_nan_2008;
214 		mips_use_nan_2008 = !!cpu_has_nan_2008;
215 		break;
216 	case RELAXED:
217 		mips_use_nan_legacy = true;
218 		mips_use_nan_2008 = true;
219 		break;
220 	}
221 }
222 
223 /*
224  * IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode override
225  * settings:
226  *
227  * strict:  accept binaries that request a NaN encoding supported by the FPU
228  * legacy:  only accept legacy-NaN binaries
229  * 2008:    only accept 2008-NaN binaries
230  * relaxed: accept any binaries regardless of whether supported by the FPU
231  */
232 static int __init ieee754_setup(char *s)
233 {
234 	if (!s)
235 		return -1;
236 	else if (!strcmp(s, "strict"))
237 		ieee754 = STRICT;
238 	else if (!strcmp(s, "legacy"))
239 		ieee754 = LEGACY;
240 	else if (!strcmp(s, "2008"))
241 		ieee754 = STD2008;
242 	else if (!strcmp(s, "relaxed"))
243 		ieee754 = RELAXED;
244 	else
245 		return -1;
246 
247 	if (!(boot_cpu_data.options & MIPS_CPU_FPU))
248 		cpu_set_nofpu_2008(&boot_cpu_data);
249 	cpu_set_nan_2008(&boot_cpu_data);
250 
251 	return 0;
252 }
253 
254 early_param("ieee754", ieee754_setup);
255 
256 /*
257  * Set the FIR feature flags for the FPU emulator.
258  */
259 static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
260 {
261 	u32 value;
262 
263 	value = 0;
264 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
265 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
266 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
267 		value |= MIPS_FPIR_D | MIPS_FPIR_S;
268 	if (c->isa_level & (MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
269 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
270 		value |= MIPS_FPIR_F64 | MIPS_FPIR_L | MIPS_FPIR_W;
271 	if (c->options & MIPS_CPU_NAN_2008)
272 		value |= MIPS_FPIR_HAS2008;
273 	c->fpu_id = value;
274 }
275 
276 /* Determined FPU emulator mask to use for the boot CPU with "nofpu".  */
277 static unsigned int mips_nofpu_msk31;
278 
279 /*
280  * Set options for FPU hardware.
281  */
282 static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
283 {
284 	c->fpu_id = cpu_get_fpu_id();
285 	mips_nofpu_msk31 = c->fpu_msk31;
286 
287 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
288 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
289 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
290 		if (c->fpu_id & MIPS_FPIR_3D)
291 			c->ases |= MIPS_ASE_MIPS3D;
292 		if (c->fpu_id & MIPS_FPIR_FREP)
293 			c->options |= MIPS_CPU_FRE;
294 	}
295 
296 	cpu_set_fpu_fcsr_mask(c);
297 	cpu_set_fpu_2008(c);
298 	cpu_set_nan_2008(c);
299 }
300 
301 /*
302  * Set options for the FPU emulator.
303  */
304 static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
305 {
306 	c->options &= ~MIPS_CPU_FPU;
307 	c->fpu_msk31 = mips_nofpu_msk31;
308 
309 	cpu_set_nofpu_2008(c);
310 	cpu_set_nan_2008(c);
311 	cpu_set_nofpu_id(c);
312 }
313 
314 static int mips_fpu_disabled;
315 
316 static int __init fpu_disable(char *s)
317 {
318 	cpu_set_nofpu_opts(&boot_cpu_data);
319 	mips_fpu_disabled = 1;
320 
321 	return 1;
322 }
323 
324 __setup("nofpu", fpu_disable);
325 
326 int mips_dsp_disabled;
327 
328 static int __init dsp_disable(char *s)
329 {
330 	cpu_data[0].ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
331 	mips_dsp_disabled = 1;
332 
333 	return 1;
334 }
335 
336 __setup("nodsp", dsp_disable);
337 
338 static int mips_htw_disabled;
339 
340 static int __init htw_disable(char *s)
341 {
342 	mips_htw_disabled = 1;
343 	cpu_data[0].options &= ~MIPS_CPU_HTW;
344 	write_c0_pwctl(read_c0_pwctl() &
345 		       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
346 
347 	return 1;
348 }
349 
350 __setup("nohtw", htw_disable);
351 
352 static int mips_ftlb_disabled;
353 static int mips_has_ftlb_configured;
354 
355 static int set_ftlb_enable(struct cpuinfo_mips *c, int enable);
356 
357 static int __init ftlb_disable(char *s)
358 {
359 	unsigned int config4, mmuextdef;
360 
361 	/*
362 	 * If the core hasn't done any FTLB configuration, there is nothing
363 	 * for us to do here.
364 	 */
365 	if (!mips_has_ftlb_configured)
366 		return 1;
367 
368 	/* Disable it in the boot cpu */
369 	if (set_ftlb_enable(&cpu_data[0], 0)) {
370 		pr_warn("Can't turn FTLB off\n");
371 		return 1;
372 	}
373 
374 	back_to_back_c0_hazard();
375 
376 	config4 = read_c0_config4();
377 
378 	/* Check that FTLB has been disabled */
379 	mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
380 	/* MMUSIZEEXT == VTLB ON, FTLB OFF */
381 	if (mmuextdef == MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT) {
382 		/* This should never happen */
383 		pr_warn("FTLB could not be disabled!\n");
384 		return 1;
385 	}
386 
387 	mips_ftlb_disabled = 1;
388 	mips_has_ftlb_configured = 0;
389 
390 	/*
391 	 * noftlb is mainly used for debug purposes so print
392 	 * an informative message instead of using pr_debug()
393 	 */
394 	pr_info("FTLB has been disabled\n");
395 
396 	/*
397 	 * Some of these bits are duplicated in the decode_config4.
398 	 * MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT is the only possible case
399 	 * once FTLB has been disabled so undo what decode_config4 did.
400 	 */
401 	cpu_data[0].tlbsize -= cpu_data[0].tlbsizeftlbways *
402 			       cpu_data[0].tlbsizeftlbsets;
403 	cpu_data[0].tlbsizeftlbsets = 0;
404 	cpu_data[0].tlbsizeftlbways = 0;
405 
406 	return 1;
407 }
408 
409 __setup("noftlb", ftlb_disable);
410 
411 
412 static inline void check_errata(void)
413 {
414 	struct cpuinfo_mips *c = &current_cpu_data;
415 
416 	switch (current_cpu_type()) {
417 	case CPU_34K:
418 		/*
419 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
420 		 * This code only handles VPE0, any SMP/RTOS code
421 		 * making use of VPE1 will be responsable for that VPE.
422 		 */
423 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
424 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
425 		break;
426 	default:
427 		break;
428 	}
429 }
430 
431 void __init check_bugs32(void)
432 {
433 	check_errata();
434 }
435 
436 /*
437  * Probe whether cpu has config register by trying to play with
438  * alternate cache bit and see whether it matters.
439  * It's used by cpu_probe to distinguish between R3000A and R3081.
440  */
441 static inline int cpu_has_confreg(void)
442 {
443 #ifdef CONFIG_CPU_R3000
444 	extern unsigned long r3k_cache_size(unsigned long);
445 	unsigned long size1, size2;
446 	unsigned long cfg = read_c0_conf();
447 
448 	size1 = r3k_cache_size(ST0_ISC);
449 	write_c0_conf(cfg ^ R30XX_CONF_AC);
450 	size2 = r3k_cache_size(ST0_ISC);
451 	write_c0_conf(cfg);
452 	return size1 != size2;
453 #else
454 	return 0;
455 #endif
456 }
457 
458 static inline void set_elf_platform(int cpu, const char *plat)
459 {
460 	if (cpu == 0)
461 		__elf_platform = plat;
462 }
463 
464 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
465 {
466 #ifdef __NEED_VMBITS_PROBE
467 	write_c0_entryhi(0x3fffffffffffe000ULL);
468 	back_to_back_c0_hazard();
469 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
470 #endif
471 }
472 
473 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
474 {
475 	switch (isa) {
476 	case MIPS_CPU_ISA_M64R2:
477 		c->isa_level |= MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2;
478 	case MIPS_CPU_ISA_M64R1:
479 		c->isa_level |= MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1;
480 	case MIPS_CPU_ISA_V:
481 		c->isa_level |= MIPS_CPU_ISA_V;
482 	case MIPS_CPU_ISA_IV:
483 		c->isa_level |= MIPS_CPU_ISA_IV;
484 	case MIPS_CPU_ISA_III:
485 		c->isa_level |= MIPS_CPU_ISA_II | MIPS_CPU_ISA_III;
486 		break;
487 
488 	/* R6 incompatible with everything else */
489 	case MIPS_CPU_ISA_M64R6:
490 		c->isa_level |= MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6;
491 	case MIPS_CPU_ISA_M32R6:
492 		c->isa_level |= MIPS_CPU_ISA_M32R6;
493 		/* Break here so we don't add incompatible ISAs */
494 		break;
495 	case MIPS_CPU_ISA_M32R2:
496 		c->isa_level |= MIPS_CPU_ISA_M32R2;
497 	case MIPS_CPU_ISA_M32R1:
498 		c->isa_level |= MIPS_CPU_ISA_M32R1;
499 	case MIPS_CPU_ISA_II:
500 		c->isa_level |= MIPS_CPU_ISA_II;
501 		break;
502 	}
503 }
504 
505 static char unknown_isa[] = KERN_ERR \
506 	"Unsupported ISA type, c0.config0: %d.";
507 
508 static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
509 {
510 
511 	unsigned int probability = c->tlbsize / c->tlbsizevtlb;
512 
513 	/*
514 	 * 0 = All TLBWR instructions go to FTLB
515 	 * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
516 	 * FTLB and 1 goes to the VTLB.
517 	 * 2 = 7:1: As above with 7:1 ratio.
518 	 * 3 = 3:1: As above with 3:1 ratio.
519 	 *
520 	 * Use the linear midpoint as the probability threshold.
521 	 */
522 	if (probability >= 12)
523 		return 1;
524 	else if (probability >= 6)
525 		return 2;
526 	else
527 		/*
528 		 * So FTLB is less than 4 times bigger than VTLB.
529 		 * A 3:1 ratio can still be useful though.
530 		 */
531 		return 3;
532 }
533 
534 static int set_ftlb_enable(struct cpuinfo_mips *c, int enable)
535 {
536 	unsigned int config;
537 
538 	/* It's implementation dependent how the FTLB can be enabled */
539 	switch (c->cputype) {
540 	case CPU_PROAPTIV:
541 	case CPU_P5600:
542 	case CPU_P6600:
543 		/* proAptiv & related cores use Config6 to enable the FTLB */
544 		config = read_c0_config6();
545 		/* Clear the old probability value */
546 		config &= ~(3 << MIPS_CONF6_FTLBP_SHIFT);
547 		if (enable)
548 			/* Enable FTLB */
549 			write_c0_config6(config |
550 					 (calculate_ftlb_probability(c)
551 					  << MIPS_CONF6_FTLBP_SHIFT)
552 					 | MIPS_CONF6_FTLBEN);
553 		else
554 			/* Disable FTLB */
555 			write_c0_config6(config &  ~MIPS_CONF6_FTLBEN);
556 		break;
557 	case CPU_I6400:
558 		/* I6400 & related cores use Config7 to configure FTLB */
559 		config = read_c0_config7();
560 		/* Clear the old probability value */
561 		config &= ~(3 << MIPS_CONF7_FTLBP_SHIFT);
562 		write_c0_config7(config | (calculate_ftlb_probability(c)
563 					   << MIPS_CONF7_FTLBP_SHIFT));
564 		break;
565 	case CPU_LOONGSON3:
566 		/* Flush ITLB, DTLB, VTLB and FTLB */
567 		write_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB |
568 			      LOONGSON_DIAG_VTLB | LOONGSON_DIAG_FTLB);
569 		/* Loongson-3 cores use Config6 to enable the FTLB */
570 		config = read_c0_config6();
571 		if (enable)
572 			/* Enable FTLB */
573 			write_c0_config6(config & ~MIPS_CONF6_FTLBDIS);
574 		else
575 			/* Disable FTLB */
576 			write_c0_config6(config | MIPS_CONF6_FTLBDIS);
577 		break;
578 	default:
579 		return 1;
580 	}
581 
582 	return 0;
583 }
584 
585 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
586 {
587 	unsigned int config0;
588 	int isa, mt;
589 
590 	config0 = read_c0_config();
591 
592 	/*
593 	 * Look for Standard TLB or Dual VTLB and FTLB
594 	 */
595 	mt = config0 & MIPS_CONF_MT;
596 	if (mt == MIPS_CONF_MT_TLB)
597 		c->options |= MIPS_CPU_TLB;
598 	else if (mt == MIPS_CONF_MT_FTLB)
599 		c->options |= MIPS_CPU_TLB | MIPS_CPU_FTLB;
600 
601 	isa = (config0 & MIPS_CONF_AT) >> 13;
602 	switch (isa) {
603 	case 0:
604 		switch ((config0 & MIPS_CONF_AR) >> 10) {
605 		case 0:
606 			set_isa(c, MIPS_CPU_ISA_M32R1);
607 			break;
608 		case 1:
609 			set_isa(c, MIPS_CPU_ISA_M32R2);
610 			break;
611 		case 2:
612 			set_isa(c, MIPS_CPU_ISA_M32R6);
613 			break;
614 		default:
615 			goto unknown;
616 		}
617 		break;
618 	case 2:
619 		switch ((config0 & MIPS_CONF_AR) >> 10) {
620 		case 0:
621 			set_isa(c, MIPS_CPU_ISA_M64R1);
622 			break;
623 		case 1:
624 			set_isa(c, MIPS_CPU_ISA_M64R2);
625 			break;
626 		case 2:
627 			set_isa(c, MIPS_CPU_ISA_M64R6);
628 			break;
629 		default:
630 			goto unknown;
631 		}
632 		break;
633 	default:
634 		goto unknown;
635 	}
636 
637 	return config0 & MIPS_CONF_M;
638 
639 unknown:
640 	panic(unknown_isa, config0);
641 }
642 
643 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
644 {
645 	unsigned int config1;
646 
647 	config1 = read_c0_config1();
648 
649 	if (config1 & MIPS_CONF1_MD)
650 		c->ases |= MIPS_ASE_MDMX;
651 	if (config1 & MIPS_CONF1_PC)
652 		c->options |= MIPS_CPU_PERF;
653 	if (config1 & MIPS_CONF1_WR)
654 		c->options |= MIPS_CPU_WATCH;
655 	if (config1 & MIPS_CONF1_CA)
656 		c->ases |= MIPS_ASE_MIPS16;
657 	if (config1 & MIPS_CONF1_EP)
658 		c->options |= MIPS_CPU_EJTAG;
659 	if (config1 & MIPS_CONF1_FP) {
660 		c->options |= MIPS_CPU_FPU;
661 		c->options |= MIPS_CPU_32FPR;
662 	}
663 	if (cpu_has_tlb) {
664 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
665 		c->tlbsizevtlb = c->tlbsize;
666 		c->tlbsizeftlbsets = 0;
667 	}
668 
669 	return config1 & MIPS_CONF_M;
670 }
671 
672 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
673 {
674 	unsigned int config2;
675 
676 	config2 = read_c0_config2();
677 
678 	if (config2 & MIPS_CONF2_SL)
679 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
680 
681 	return config2 & MIPS_CONF_M;
682 }
683 
684 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
685 {
686 	unsigned int config3;
687 
688 	config3 = read_c0_config3();
689 
690 	if (config3 & MIPS_CONF3_SM) {
691 		c->ases |= MIPS_ASE_SMARTMIPS;
692 		c->options |= MIPS_CPU_RIXI | MIPS_CPU_CTXTC;
693 	}
694 	if (config3 & MIPS_CONF3_RXI)
695 		c->options |= MIPS_CPU_RIXI;
696 	if (config3 & MIPS_CONF3_CTXTC)
697 		c->options |= MIPS_CPU_CTXTC;
698 	if (config3 & MIPS_CONF3_DSP)
699 		c->ases |= MIPS_ASE_DSP;
700 	if (config3 & MIPS_CONF3_DSP2P) {
701 		c->ases |= MIPS_ASE_DSP2P;
702 		if (cpu_has_mips_r6)
703 			c->ases |= MIPS_ASE_DSP3;
704 	}
705 	if (config3 & MIPS_CONF3_VINT)
706 		c->options |= MIPS_CPU_VINT;
707 	if (config3 & MIPS_CONF3_VEIC)
708 		c->options |= MIPS_CPU_VEIC;
709 	if (config3 & MIPS_CONF3_LPA)
710 		c->options |= MIPS_CPU_LPA;
711 	if (config3 & MIPS_CONF3_MT)
712 		c->ases |= MIPS_ASE_MIPSMT;
713 	if (config3 & MIPS_CONF3_ULRI)
714 		c->options |= MIPS_CPU_ULRI;
715 	if (config3 & MIPS_CONF3_ISA)
716 		c->options |= MIPS_CPU_MICROMIPS;
717 	if (config3 & MIPS_CONF3_VZ)
718 		c->ases |= MIPS_ASE_VZ;
719 	if (config3 & MIPS_CONF3_SC)
720 		c->options |= MIPS_CPU_SEGMENTS;
721 	if (config3 & MIPS_CONF3_BI)
722 		c->options |= MIPS_CPU_BADINSTR;
723 	if (config3 & MIPS_CONF3_BP)
724 		c->options |= MIPS_CPU_BADINSTRP;
725 	if (config3 & MIPS_CONF3_MSA)
726 		c->ases |= MIPS_ASE_MSA;
727 	if (config3 & MIPS_CONF3_PW) {
728 		c->htw_seq = 0;
729 		c->options |= MIPS_CPU_HTW;
730 	}
731 	if (config3 & MIPS_CONF3_CDMM)
732 		c->options |= MIPS_CPU_CDMM;
733 	if (config3 & MIPS_CONF3_SP)
734 		c->options |= MIPS_CPU_SP;
735 
736 	return config3 & MIPS_CONF_M;
737 }
738 
739 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
740 {
741 	unsigned int config4;
742 	unsigned int newcf4;
743 	unsigned int mmuextdef;
744 	unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE;
745 	unsigned long asid_mask;
746 
747 	config4 = read_c0_config4();
748 
749 	if (cpu_has_tlb) {
750 		if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
751 			c->options |= MIPS_CPU_TLBINV;
752 
753 		/*
754 		 * R6 has dropped the MMUExtDef field from config4.
755 		 * On R6 the fields always describe the FTLB, and only if it is
756 		 * present according to Config.MT.
757 		 */
758 		if (!cpu_has_mips_r6)
759 			mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
760 		else if (cpu_has_ftlb)
761 			mmuextdef = MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT;
762 		else
763 			mmuextdef = 0;
764 
765 		switch (mmuextdef) {
766 		case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT:
767 			c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
768 			c->tlbsizevtlb = c->tlbsize;
769 			break;
770 		case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
771 			c->tlbsizevtlb +=
772 				((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
773 				  MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40;
774 			c->tlbsize = c->tlbsizevtlb;
775 			ftlb_page = MIPS_CONF4_VFTLBPAGESIZE;
776 			/* fall through */
777 		case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
778 			if (mips_ftlb_disabled)
779 				break;
780 			newcf4 = (config4 & ~ftlb_page) |
781 				(page_size_ftlb(mmuextdef) <<
782 				 MIPS_CONF4_FTLBPAGESIZE_SHIFT);
783 			write_c0_config4(newcf4);
784 			back_to_back_c0_hazard();
785 			config4 = read_c0_config4();
786 			if (config4 != newcf4) {
787 				pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n",
788 				       PAGE_SIZE, config4);
789 				/* Switch FTLB off */
790 				set_ftlb_enable(c, 0);
791 				break;
792 			}
793 			c->tlbsizeftlbsets = 1 <<
794 				((config4 & MIPS_CONF4_FTLBSETS) >>
795 				 MIPS_CONF4_FTLBSETS_SHIFT);
796 			c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >>
797 					      MIPS_CONF4_FTLBWAYS_SHIFT) + 2;
798 			c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets;
799 			mips_has_ftlb_configured = 1;
800 			break;
801 		}
802 	}
803 
804 	c->kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
805 				>> MIPS_CONF4_KSCREXIST_SHIFT;
806 
807 	asid_mask = MIPS_ENTRYHI_ASID;
808 	if (config4 & MIPS_CONF4_AE)
809 		asid_mask |= MIPS_ENTRYHI_ASIDX;
810 	set_cpu_asid_mask(c, asid_mask);
811 
812 	/*
813 	 * Warn if the computed ASID mask doesn't match the mask the kernel
814 	 * is built for. This may indicate either a serious problem or an
815 	 * easy optimisation opportunity, but either way should be addressed.
816 	 */
817 	WARN_ON(asid_mask != cpu_asid_mask(c));
818 
819 	return config4 & MIPS_CONF_M;
820 }
821 
822 static inline unsigned int decode_config5(struct cpuinfo_mips *c)
823 {
824 	unsigned int config5;
825 
826 	config5 = read_c0_config5();
827 	config5 &= ~(MIPS_CONF5_UFR | MIPS_CONF5_UFE);
828 	write_c0_config5(config5);
829 
830 	if (config5 & MIPS_CONF5_EVA)
831 		c->options |= MIPS_CPU_EVA;
832 	if (config5 & MIPS_CONF5_MRP)
833 		c->options |= MIPS_CPU_MAAR;
834 	if (config5 & MIPS_CONF5_LLB)
835 		c->options |= MIPS_CPU_RW_LLB;
836 	if (config5 & MIPS_CONF5_MVH)
837 		c->options |= MIPS_CPU_MVH;
838 	if (cpu_has_mips_r6 && (config5 & MIPS_CONF5_VP))
839 		c->options |= MIPS_CPU_VP;
840 
841 	return config5 & MIPS_CONF_M;
842 }
843 
844 static void decode_configs(struct cpuinfo_mips *c)
845 {
846 	int ok;
847 
848 	/* MIPS32 or MIPS64 compliant CPU.  */
849 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
850 		     MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
851 
852 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
853 
854 	/* Enable FTLB if present and not disabled */
855 	set_ftlb_enable(c, !mips_ftlb_disabled);
856 
857 	ok = decode_config0(c);			/* Read Config registers.  */
858 	BUG_ON(!ok);				/* Arch spec violation!	 */
859 	if (ok)
860 		ok = decode_config1(c);
861 	if (ok)
862 		ok = decode_config2(c);
863 	if (ok)
864 		ok = decode_config3(c);
865 	if (ok)
866 		ok = decode_config4(c);
867 	if (ok)
868 		ok = decode_config5(c);
869 
870 	/* Probe the EBase.WG bit */
871 	if (cpu_has_mips_r2_r6) {
872 		u64 ebase;
873 		unsigned int status;
874 
875 		/* {read,write}_c0_ebase_64() may be UNDEFINED prior to r6 */
876 		ebase = cpu_has_mips64r6 ? read_c0_ebase_64()
877 					 : (s32)read_c0_ebase();
878 		if (ebase & MIPS_EBASE_WG) {
879 			/* WG bit already set, we can avoid the clumsy probe */
880 			c->options |= MIPS_CPU_EBASE_WG;
881 		} else {
882 			/* Its UNDEFINED to change EBase while BEV=0 */
883 			status = read_c0_status();
884 			write_c0_status(status | ST0_BEV);
885 			irq_enable_hazard();
886 			/*
887 			 * On pre-r6 cores, this may well clobber the upper bits
888 			 * of EBase. This is hard to avoid without potentially
889 			 * hitting UNDEFINED dm*c0 behaviour if EBase is 32-bit.
890 			 */
891 			if (cpu_has_mips64r6)
892 				write_c0_ebase_64(ebase | MIPS_EBASE_WG);
893 			else
894 				write_c0_ebase(ebase | MIPS_EBASE_WG);
895 			back_to_back_c0_hazard();
896 			/* Restore BEV */
897 			write_c0_status(status);
898 			if (read_c0_ebase() & MIPS_EBASE_WG) {
899 				c->options |= MIPS_CPU_EBASE_WG;
900 				write_c0_ebase(ebase);
901 			}
902 		}
903 	}
904 
905 	mips_probe_watch_registers(c);
906 
907 #ifndef CONFIG_MIPS_CPS
908 	if (cpu_has_mips_r2_r6) {
909 		c->core = get_ebase_cpunum();
910 		if (cpu_has_mipsmt)
911 			c->core >>= fls(core_nvpes()) - 1;
912 	}
913 #endif
914 }
915 
916 /*
917  * Probe for certain guest capabilities by writing config bits and reading back.
918  * Finally write back the original value.
919  */
920 #define probe_gc0_config(name, maxconf, bits)				\
921 do {									\
922 	unsigned int tmp;						\
923 	tmp = read_gc0_##name();					\
924 	write_gc0_##name(tmp | (bits));					\
925 	back_to_back_c0_hazard();					\
926 	maxconf = read_gc0_##name();					\
927 	write_gc0_##name(tmp);						\
928 } while (0)
929 
930 /*
931  * Probe for dynamic guest capabilities by changing certain config bits and
932  * reading back to see if they change. Finally write back the original value.
933  */
934 #define probe_gc0_config_dyn(name, maxconf, dynconf, bits)		\
935 do {									\
936 	maxconf = read_gc0_##name();					\
937 	write_gc0_##name(maxconf ^ (bits));				\
938 	back_to_back_c0_hazard();					\
939 	dynconf = maxconf ^ read_gc0_##name();				\
940 	write_gc0_##name(maxconf);					\
941 	maxconf |= dynconf;						\
942 } while (0)
943 
944 static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c)
945 {
946 	unsigned int config0;
947 
948 	probe_gc0_config(config, config0, MIPS_CONF_M);
949 
950 	if (config0 & MIPS_CONF_M)
951 		c->guest.conf |= BIT(1);
952 	return config0 & MIPS_CONF_M;
953 }
954 
955 static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c)
956 {
957 	unsigned int config1, config1_dyn;
958 
959 	probe_gc0_config_dyn(config1, config1, config1_dyn,
960 			     MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR |
961 			     MIPS_CONF1_FP);
962 
963 	if (config1 & MIPS_CONF1_FP)
964 		c->guest.options |= MIPS_CPU_FPU;
965 	if (config1_dyn & MIPS_CONF1_FP)
966 		c->guest.options_dyn |= MIPS_CPU_FPU;
967 
968 	if (config1 & MIPS_CONF1_WR)
969 		c->guest.options |= MIPS_CPU_WATCH;
970 	if (config1_dyn & MIPS_CONF1_WR)
971 		c->guest.options_dyn |= MIPS_CPU_WATCH;
972 
973 	if (config1 & MIPS_CONF1_PC)
974 		c->guest.options |= MIPS_CPU_PERF;
975 	if (config1_dyn & MIPS_CONF1_PC)
976 		c->guest.options_dyn |= MIPS_CPU_PERF;
977 
978 	if (config1 & MIPS_CONF_M)
979 		c->guest.conf |= BIT(2);
980 	return config1 & MIPS_CONF_M;
981 }
982 
983 static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c)
984 {
985 	unsigned int config2;
986 
987 	probe_gc0_config(config2, config2, MIPS_CONF_M);
988 
989 	if (config2 & MIPS_CONF_M)
990 		c->guest.conf |= BIT(3);
991 	return config2 & MIPS_CONF_M;
992 }
993 
994 static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c)
995 {
996 	unsigned int config3, config3_dyn;
997 
998 	probe_gc0_config_dyn(config3, config3, config3_dyn,
999 			     MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_CTXTC);
1000 
1001 	if (config3 & MIPS_CONF3_CTXTC)
1002 		c->guest.options |= MIPS_CPU_CTXTC;
1003 	if (config3_dyn & MIPS_CONF3_CTXTC)
1004 		c->guest.options_dyn |= MIPS_CPU_CTXTC;
1005 
1006 	if (config3 & MIPS_CONF3_PW)
1007 		c->guest.options |= MIPS_CPU_HTW;
1008 
1009 	if (config3 & MIPS_CONF3_SC)
1010 		c->guest.options |= MIPS_CPU_SEGMENTS;
1011 
1012 	if (config3 & MIPS_CONF3_BI)
1013 		c->guest.options |= MIPS_CPU_BADINSTR;
1014 	if (config3 & MIPS_CONF3_BP)
1015 		c->guest.options |= MIPS_CPU_BADINSTRP;
1016 
1017 	if (config3 & MIPS_CONF3_MSA)
1018 		c->guest.ases |= MIPS_ASE_MSA;
1019 	if (config3_dyn & MIPS_CONF3_MSA)
1020 		c->guest.ases_dyn |= MIPS_ASE_MSA;
1021 
1022 	if (config3 & MIPS_CONF_M)
1023 		c->guest.conf |= BIT(4);
1024 	return config3 & MIPS_CONF_M;
1025 }
1026 
1027 static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c)
1028 {
1029 	unsigned int config4;
1030 
1031 	probe_gc0_config(config4, config4,
1032 			 MIPS_CONF_M | MIPS_CONF4_KSCREXIST);
1033 
1034 	c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
1035 				>> MIPS_CONF4_KSCREXIST_SHIFT;
1036 
1037 	if (config4 & MIPS_CONF_M)
1038 		c->guest.conf |= BIT(5);
1039 	return config4 & MIPS_CONF_M;
1040 }
1041 
1042 static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c)
1043 {
1044 	unsigned int config5, config5_dyn;
1045 
1046 	probe_gc0_config_dyn(config5, config5, config5_dyn,
1047 			 MIPS_CONF_M | MIPS_CONF5_MRP);
1048 
1049 	if (config5 & MIPS_CONF5_MRP)
1050 		c->guest.options |= MIPS_CPU_MAAR;
1051 	if (config5_dyn & MIPS_CONF5_MRP)
1052 		c->guest.options_dyn |= MIPS_CPU_MAAR;
1053 
1054 	if (config5 & MIPS_CONF5_LLB)
1055 		c->guest.options |= MIPS_CPU_RW_LLB;
1056 
1057 	if (config5 & MIPS_CONF_M)
1058 		c->guest.conf |= BIT(6);
1059 	return config5 & MIPS_CONF_M;
1060 }
1061 
1062 static inline void decode_guest_configs(struct cpuinfo_mips *c)
1063 {
1064 	unsigned int ok;
1065 
1066 	ok = decode_guest_config0(c);
1067 	if (ok)
1068 		ok = decode_guest_config1(c);
1069 	if (ok)
1070 		ok = decode_guest_config2(c);
1071 	if (ok)
1072 		ok = decode_guest_config3(c);
1073 	if (ok)
1074 		ok = decode_guest_config4(c);
1075 	if (ok)
1076 		decode_guest_config5(c);
1077 }
1078 
1079 static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c)
1080 {
1081 	unsigned int guestctl0, temp;
1082 
1083 	guestctl0 = read_c0_guestctl0();
1084 
1085 	if (guestctl0 & MIPS_GCTL0_G0E)
1086 		c->options |= MIPS_CPU_GUESTCTL0EXT;
1087 	if (guestctl0 & MIPS_GCTL0_G1)
1088 		c->options |= MIPS_CPU_GUESTCTL1;
1089 	if (guestctl0 & MIPS_GCTL0_G2)
1090 		c->options |= MIPS_CPU_GUESTCTL2;
1091 	if (!(guestctl0 & MIPS_GCTL0_RAD)) {
1092 		c->options |= MIPS_CPU_GUESTID;
1093 
1094 		/*
1095 		 * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0
1096 		 * first, otherwise all data accesses will be fully virtualised
1097 		 * as if they were performed by guest mode.
1098 		 */
1099 		write_c0_guestctl1(0);
1100 		tlbw_use_hazard();
1101 
1102 		write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG);
1103 		back_to_back_c0_hazard();
1104 		temp = read_c0_guestctl0();
1105 
1106 		if (temp & MIPS_GCTL0_DRG) {
1107 			write_c0_guestctl0(guestctl0);
1108 			c->options |= MIPS_CPU_DRG;
1109 		}
1110 	}
1111 }
1112 
1113 static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c)
1114 {
1115 	if (cpu_has_guestid) {
1116 		/* determine the number of bits of GuestID available */
1117 		write_c0_guestctl1(MIPS_GCTL1_ID);
1118 		back_to_back_c0_hazard();
1119 		c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID)
1120 						>> MIPS_GCTL1_ID_SHIFT;
1121 		write_c0_guestctl1(0);
1122 	}
1123 }
1124 
1125 static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c)
1126 {
1127 	/* determine the number of bits of GTOffset available */
1128 	write_c0_gtoffset(0xffffffff);
1129 	back_to_back_c0_hazard();
1130 	c->gtoffset_mask = read_c0_gtoffset();
1131 	write_c0_gtoffset(0);
1132 }
1133 
1134 static inline void cpu_probe_vz(struct cpuinfo_mips *c)
1135 {
1136 	cpu_probe_guestctl0(c);
1137 	if (cpu_has_guestctl1)
1138 		cpu_probe_guestctl1(c);
1139 
1140 	cpu_probe_gtoffset(c);
1141 
1142 	decode_guest_configs(c);
1143 }
1144 
1145 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
1146 		| MIPS_CPU_COUNTER)
1147 
1148 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
1149 {
1150 	switch (c->processor_id & PRID_IMP_MASK) {
1151 	case PRID_IMP_R2000:
1152 		c->cputype = CPU_R2000;
1153 		__cpu_name[cpu] = "R2000";
1154 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1155 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1156 			     MIPS_CPU_NOFPUEX;
1157 		if (__cpu_has_fpu())
1158 			c->options |= MIPS_CPU_FPU;
1159 		c->tlbsize = 64;
1160 		break;
1161 	case PRID_IMP_R3000:
1162 		if ((c->processor_id & PRID_REV_MASK) == PRID_REV_R3000A) {
1163 			if (cpu_has_confreg()) {
1164 				c->cputype = CPU_R3081E;
1165 				__cpu_name[cpu] = "R3081";
1166 			} else {
1167 				c->cputype = CPU_R3000A;
1168 				__cpu_name[cpu] = "R3000A";
1169 			}
1170 		} else {
1171 			c->cputype = CPU_R3000;
1172 			__cpu_name[cpu] = "R3000";
1173 		}
1174 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1175 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1176 			     MIPS_CPU_NOFPUEX;
1177 		if (__cpu_has_fpu())
1178 			c->options |= MIPS_CPU_FPU;
1179 		c->tlbsize = 64;
1180 		break;
1181 	case PRID_IMP_R4000:
1182 		if (read_c0_config() & CONF_SC) {
1183 			if ((c->processor_id & PRID_REV_MASK) >=
1184 			    PRID_REV_R4400) {
1185 				c->cputype = CPU_R4400PC;
1186 				__cpu_name[cpu] = "R4400PC";
1187 			} else {
1188 				c->cputype = CPU_R4000PC;
1189 				__cpu_name[cpu] = "R4000PC";
1190 			}
1191 		} else {
1192 			int cca = read_c0_config() & CONF_CM_CMASK;
1193 			int mc;
1194 
1195 			/*
1196 			 * SC and MC versions can't be reliably told apart,
1197 			 * but only the latter support coherent caching
1198 			 * modes so assume the firmware has set the KSEG0
1199 			 * coherency attribute reasonably (if uncached, we
1200 			 * assume SC).
1201 			 */
1202 			switch (cca) {
1203 			case CONF_CM_CACHABLE_CE:
1204 			case CONF_CM_CACHABLE_COW:
1205 			case CONF_CM_CACHABLE_CUW:
1206 				mc = 1;
1207 				break;
1208 			default:
1209 				mc = 0;
1210 				break;
1211 			}
1212 			if ((c->processor_id & PRID_REV_MASK) >=
1213 			    PRID_REV_R4400) {
1214 				c->cputype = mc ? CPU_R4400MC : CPU_R4400SC;
1215 				__cpu_name[cpu] = mc ? "R4400MC" : "R4400SC";
1216 			} else {
1217 				c->cputype = mc ? CPU_R4000MC : CPU_R4000SC;
1218 				__cpu_name[cpu] = mc ? "R4000MC" : "R4000SC";
1219 			}
1220 		}
1221 
1222 		set_isa(c, MIPS_CPU_ISA_III);
1223 		c->fpu_msk31 |= FPU_CSR_CONDX;
1224 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1225 			     MIPS_CPU_WATCH | MIPS_CPU_VCE |
1226 			     MIPS_CPU_LLSC;
1227 		c->tlbsize = 48;
1228 		break;
1229 	case PRID_IMP_VR41XX:
1230 		set_isa(c, MIPS_CPU_ISA_III);
1231 		c->fpu_msk31 |= FPU_CSR_CONDX;
1232 		c->options = R4K_OPTS;
1233 		c->tlbsize = 32;
1234 		switch (c->processor_id & 0xf0) {
1235 		case PRID_REV_VR4111:
1236 			c->cputype = CPU_VR4111;
1237 			__cpu_name[cpu] = "NEC VR4111";
1238 			break;
1239 		case PRID_REV_VR4121:
1240 			c->cputype = CPU_VR4121;
1241 			__cpu_name[cpu] = "NEC VR4121";
1242 			break;
1243 		case PRID_REV_VR4122:
1244 			if ((c->processor_id & 0xf) < 0x3) {
1245 				c->cputype = CPU_VR4122;
1246 				__cpu_name[cpu] = "NEC VR4122";
1247 			} else {
1248 				c->cputype = CPU_VR4181A;
1249 				__cpu_name[cpu] = "NEC VR4181A";
1250 			}
1251 			break;
1252 		case PRID_REV_VR4130:
1253 			if ((c->processor_id & 0xf) < 0x4) {
1254 				c->cputype = CPU_VR4131;
1255 				__cpu_name[cpu] = "NEC VR4131";
1256 			} else {
1257 				c->cputype = CPU_VR4133;
1258 				c->options |= MIPS_CPU_LLSC;
1259 				__cpu_name[cpu] = "NEC VR4133";
1260 			}
1261 			break;
1262 		default:
1263 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
1264 			c->cputype = CPU_VR41XX;
1265 			__cpu_name[cpu] = "NEC Vr41xx";
1266 			break;
1267 		}
1268 		break;
1269 	case PRID_IMP_R4300:
1270 		c->cputype = CPU_R4300;
1271 		__cpu_name[cpu] = "R4300";
1272 		set_isa(c, MIPS_CPU_ISA_III);
1273 		c->fpu_msk31 |= FPU_CSR_CONDX;
1274 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1275 			     MIPS_CPU_LLSC;
1276 		c->tlbsize = 32;
1277 		break;
1278 	case PRID_IMP_R4600:
1279 		c->cputype = CPU_R4600;
1280 		__cpu_name[cpu] = "R4600";
1281 		set_isa(c, MIPS_CPU_ISA_III);
1282 		c->fpu_msk31 |= FPU_CSR_CONDX;
1283 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1284 			     MIPS_CPU_LLSC;
1285 		c->tlbsize = 48;
1286 		break;
1287 	#if 0
1288 	case PRID_IMP_R4650:
1289 		/*
1290 		 * This processor doesn't have an MMU, so it's not
1291 		 * "real easy" to run Linux on it. It is left purely
1292 		 * for documentation.  Commented out because it shares
1293 		 * it's c0_prid id number with the TX3900.
1294 		 */
1295 		c->cputype = CPU_R4650;
1296 		__cpu_name[cpu] = "R4650";
1297 		set_isa(c, MIPS_CPU_ISA_III);
1298 		c->fpu_msk31 |= FPU_CSR_CONDX;
1299 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
1300 		c->tlbsize = 48;
1301 		break;
1302 	#endif
1303 	case PRID_IMP_TX39:
1304 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1305 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
1306 
1307 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
1308 			c->cputype = CPU_TX3927;
1309 			__cpu_name[cpu] = "TX3927";
1310 			c->tlbsize = 64;
1311 		} else {
1312 			switch (c->processor_id & PRID_REV_MASK) {
1313 			case PRID_REV_TX3912:
1314 				c->cputype = CPU_TX3912;
1315 				__cpu_name[cpu] = "TX3912";
1316 				c->tlbsize = 32;
1317 				break;
1318 			case PRID_REV_TX3922:
1319 				c->cputype = CPU_TX3922;
1320 				__cpu_name[cpu] = "TX3922";
1321 				c->tlbsize = 64;
1322 				break;
1323 			}
1324 		}
1325 		break;
1326 	case PRID_IMP_R4700:
1327 		c->cputype = CPU_R4700;
1328 		__cpu_name[cpu] = "R4700";
1329 		set_isa(c, MIPS_CPU_ISA_III);
1330 		c->fpu_msk31 |= FPU_CSR_CONDX;
1331 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1332 			     MIPS_CPU_LLSC;
1333 		c->tlbsize = 48;
1334 		break;
1335 	case PRID_IMP_TX49:
1336 		c->cputype = CPU_TX49XX;
1337 		__cpu_name[cpu] = "R49XX";
1338 		set_isa(c, MIPS_CPU_ISA_III);
1339 		c->fpu_msk31 |= FPU_CSR_CONDX;
1340 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
1341 		if (!(c->processor_id & 0x08))
1342 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
1343 		c->tlbsize = 48;
1344 		break;
1345 	case PRID_IMP_R5000:
1346 		c->cputype = CPU_R5000;
1347 		__cpu_name[cpu] = "R5000";
1348 		set_isa(c, MIPS_CPU_ISA_IV);
1349 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1350 			     MIPS_CPU_LLSC;
1351 		c->tlbsize = 48;
1352 		break;
1353 	case PRID_IMP_R5432:
1354 		c->cputype = CPU_R5432;
1355 		__cpu_name[cpu] = "R5432";
1356 		set_isa(c, MIPS_CPU_ISA_IV);
1357 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1358 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1359 		c->tlbsize = 48;
1360 		break;
1361 	case PRID_IMP_R5500:
1362 		c->cputype = CPU_R5500;
1363 		__cpu_name[cpu] = "R5500";
1364 		set_isa(c, MIPS_CPU_ISA_IV);
1365 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1366 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1367 		c->tlbsize = 48;
1368 		break;
1369 	case PRID_IMP_NEVADA:
1370 		c->cputype = CPU_NEVADA;
1371 		__cpu_name[cpu] = "Nevada";
1372 		set_isa(c, MIPS_CPU_ISA_IV);
1373 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1374 			     MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
1375 		c->tlbsize = 48;
1376 		break;
1377 	case PRID_IMP_R6000:
1378 		c->cputype = CPU_R6000;
1379 		__cpu_name[cpu] = "R6000";
1380 		set_isa(c, MIPS_CPU_ISA_II);
1381 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1382 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
1383 			     MIPS_CPU_LLSC;
1384 		c->tlbsize = 32;
1385 		break;
1386 	case PRID_IMP_R6000A:
1387 		c->cputype = CPU_R6000A;
1388 		__cpu_name[cpu] = "R6000A";
1389 		set_isa(c, MIPS_CPU_ISA_II);
1390 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1391 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
1392 			     MIPS_CPU_LLSC;
1393 		c->tlbsize = 32;
1394 		break;
1395 	case PRID_IMP_RM7000:
1396 		c->cputype = CPU_RM7000;
1397 		__cpu_name[cpu] = "RM7000";
1398 		set_isa(c, MIPS_CPU_ISA_IV);
1399 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1400 			     MIPS_CPU_LLSC;
1401 		/*
1402 		 * Undocumented RM7000:	 Bit 29 in the info register of
1403 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
1404 		 * entries.
1405 		 *
1406 		 * 29	   1 =>	   64 entry JTLB
1407 		 *	   0 =>	   48 entry JTLB
1408 		 */
1409 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
1410 		break;
1411 	case PRID_IMP_R8000:
1412 		c->cputype = CPU_R8000;
1413 		__cpu_name[cpu] = "RM8000";
1414 		set_isa(c, MIPS_CPU_ISA_IV);
1415 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
1416 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1417 			     MIPS_CPU_LLSC;
1418 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
1419 		break;
1420 	case PRID_IMP_R10000:
1421 		c->cputype = CPU_R10000;
1422 		__cpu_name[cpu] = "R10000";
1423 		set_isa(c, MIPS_CPU_ISA_IV);
1424 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1425 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1426 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1427 			     MIPS_CPU_LLSC;
1428 		c->tlbsize = 64;
1429 		break;
1430 	case PRID_IMP_R12000:
1431 		c->cputype = CPU_R12000;
1432 		__cpu_name[cpu] = "R12000";
1433 		set_isa(c, MIPS_CPU_ISA_IV);
1434 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1435 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1436 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1437 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1438 		c->tlbsize = 64;
1439 		break;
1440 	case PRID_IMP_R14000:
1441 		if (((c->processor_id >> 4) & 0x0f) > 2) {
1442 			c->cputype = CPU_R16000;
1443 			__cpu_name[cpu] = "R16000";
1444 		} else {
1445 			c->cputype = CPU_R14000;
1446 			__cpu_name[cpu] = "R14000";
1447 		}
1448 		set_isa(c, MIPS_CPU_ISA_IV);
1449 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1450 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1451 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1452 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1453 		c->tlbsize = 64;
1454 		break;
1455 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1456 		switch (c->processor_id & PRID_REV_MASK) {
1457 		case PRID_REV_LOONGSON2E:
1458 			c->cputype = CPU_LOONGSON2;
1459 			__cpu_name[cpu] = "ICT Loongson-2";
1460 			set_elf_platform(cpu, "loongson2e");
1461 			set_isa(c, MIPS_CPU_ISA_III);
1462 			c->fpu_msk31 |= FPU_CSR_CONDX;
1463 			break;
1464 		case PRID_REV_LOONGSON2F:
1465 			c->cputype = CPU_LOONGSON2;
1466 			__cpu_name[cpu] = "ICT Loongson-2";
1467 			set_elf_platform(cpu, "loongson2f");
1468 			set_isa(c, MIPS_CPU_ISA_III);
1469 			c->fpu_msk31 |= FPU_CSR_CONDX;
1470 			break;
1471 		case PRID_REV_LOONGSON3A_R1:
1472 			c->cputype = CPU_LOONGSON3;
1473 			__cpu_name[cpu] = "ICT Loongson-3";
1474 			set_elf_platform(cpu, "loongson3a");
1475 			set_isa(c, MIPS_CPU_ISA_M64R1);
1476 			break;
1477 		case PRID_REV_LOONGSON3B_R1:
1478 		case PRID_REV_LOONGSON3B_R2:
1479 			c->cputype = CPU_LOONGSON3;
1480 			__cpu_name[cpu] = "ICT Loongson-3";
1481 			set_elf_platform(cpu, "loongson3b");
1482 			set_isa(c, MIPS_CPU_ISA_M64R1);
1483 			break;
1484 		}
1485 
1486 		c->options = R4K_OPTS |
1487 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
1488 			     MIPS_CPU_32FPR;
1489 		c->tlbsize = 64;
1490 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1491 		break;
1492 	case PRID_IMP_LOONGSON_32:  /* Loongson-1 */
1493 		decode_configs(c);
1494 
1495 		c->cputype = CPU_LOONGSON1;
1496 
1497 		switch (c->processor_id & PRID_REV_MASK) {
1498 		case PRID_REV_LOONGSON1B:
1499 			__cpu_name[cpu] = "Loongson 1B";
1500 			break;
1501 		}
1502 
1503 		break;
1504 	}
1505 }
1506 
1507 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
1508 {
1509 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1510 	switch (c->processor_id & PRID_IMP_MASK) {
1511 	case PRID_IMP_QEMU_GENERIC:
1512 		c->writecombine = _CACHE_UNCACHED;
1513 		c->cputype = CPU_QEMU_GENERIC;
1514 		__cpu_name[cpu] = "MIPS GENERIC QEMU";
1515 		break;
1516 	case PRID_IMP_4KC:
1517 		c->cputype = CPU_4KC;
1518 		c->writecombine = _CACHE_UNCACHED;
1519 		__cpu_name[cpu] = "MIPS 4Kc";
1520 		break;
1521 	case PRID_IMP_4KEC:
1522 	case PRID_IMP_4KECR2:
1523 		c->cputype = CPU_4KEC;
1524 		c->writecombine = _CACHE_UNCACHED;
1525 		__cpu_name[cpu] = "MIPS 4KEc";
1526 		break;
1527 	case PRID_IMP_4KSC:
1528 	case PRID_IMP_4KSD:
1529 		c->cputype = CPU_4KSC;
1530 		c->writecombine = _CACHE_UNCACHED;
1531 		__cpu_name[cpu] = "MIPS 4KSc";
1532 		break;
1533 	case PRID_IMP_5KC:
1534 		c->cputype = CPU_5KC;
1535 		c->writecombine = _CACHE_UNCACHED;
1536 		__cpu_name[cpu] = "MIPS 5Kc";
1537 		break;
1538 	case PRID_IMP_5KE:
1539 		c->cputype = CPU_5KE;
1540 		c->writecombine = _CACHE_UNCACHED;
1541 		__cpu_name[cpu] = "MIPS 5KE";
1542 		break;
1543 	case PRID_IMP_20KC:
1544 		c->cputype = CPU_20KC;
1545 		c->writecombine = _CACHE_UNCACHED;
1546 		__cpu_name[cpu] = "MIPS 20Kc";
1547 		break;
1548 	case PRID_IMP_24K:
1549 		c->cputype = CPU_24K;
1550 		c->writecombine = _CACHE_UNCACHED;
1551 		__cpu_name[cpu] = "MIPS 24Kc";
1552 		break;
1553 	case PRID_IMP_24KE:
1554 		c->cputype = CPU_24K;
1555 		c->writecombine = _CACHE_UNCACHED;
1556 		__cpu_name[cpu] = "MIPS 24KEc";
1557 		break;
1558 	case PRID_IMP_25KF:
1559 		c->cputype = CPU_25KF;
1560 		c->writecombine = _CACHE_UNCACHED;
1561 		__cpu_name[cpu] = "MIPS 25Kc";
1562 		break;
1563 	case PRID_IMP_34K:
1564 		c->cputype = CPU_34K;
1565 		c->writecombine = _CACHE_UNCACHED;
1566 		__cpu_name[cpu] = "MIPS 34Kc";
1567 		break;
1568 	case PRID_IMP_74K:
1569 		c->cputype = CPU_74K;
1570 		c->writecombine = _CACHE_UNCACHED;
1571 		__cpu_name[cpu] = "MIPS 74Kc";
1572 		break;
1573 	case PRID_IMP_M14KC:
1574 		c->cputype = CPU_M14KC;
1575 		c->writecombine = _CACHE_UNCACHED;
1576 		__cpu_name[cpu] = "MIPS M14Kc";
1577 		break;
1578 	case PRID_IMP_M14KEC:
1579 		c->cputype = CPU_M14KEC;
1580 		c->writecombine = _CACHE_UNCACHED;
1581 		__cpu_name[cpu] = "MIPS M14KEc";
1582 		break;
1583 	case PRID_IMP_1004K:
1584 		c->cputype = CPU_1004K;
1585 		c->writecombine = _CACHE_UNCACHED;
1586 		__cpu_name[cpu] = "MIPS 1004Kc";
1587 		break;
1588 	case PRID_IMP_1074K:
1589 		c->cputype = CPU_1074K;
1590 		c->writecombine = _CACHE_UNCACHED;
1591 		__cpu_name[cpu] = "MIPS 1074Kc";
1592 		break;
1593 	case PRID_IMP_INTERAPTIV_UP:
1594 		c->cputype = CPU_INTERAPTIV;
1595 		__cpu_name[cpu] = "MIPS interAptiv";
1596 		break;
1597 	case PRID_IMP_INTERAPTIV_MP:
1598 		c->cputype = CPU_INTERAPTIV;
1599 		__cpu_name[cpu] = "MIPS interAptiv (multi)";
1600 		break;
1601 	case PRID_IMP_PROAPTIV_UP:
1602 		c->cputype = CPU_PROAPTIV;
1603 		__cpu_name[cpu] = "MIPS proAptiv";
1604 		break;
1605 	case PRID_IMP_PROAPTIV_MP:
1606 		c->cputype = CPU_PROAPTIV;
1607 		__cpu_name[cpu] = "MIPS proAptiv (multi)";
1608 		break;
1609 	case PRID_IMP_P5600:
1610 		c->cputype = CPU_P5600;
1611 		__cpu_name[cpu] = "MIPS P5600";
1612 		break;
1613 	case PRID_IMP_P6600:
1614 		c->cputype = CPU_P6600;
1615 		__cpu_name[cpu] = "MIPS P6600";
1616 		break;
1617 	case PRID_IMP_I6400:
1618 		c->cputype = CPU_I6400;
1619 		__cpu_name[cpu] = "MIPS I6400";
1620 		break;
1621 	case PRID_IMP_M5150:
1622 		c->cputype = CPU_M5150;
1623 		__cpu_name[cpu] = "MIPS M5150";
1624 		break;
1625 	case PRID_IMP_M6250:
1626 		c->cputype = CPU_M6250;
1627 		__cpu_name[cpu] = "MIPS M6250";
1628 		break;
1629 	}
1630 
1631 	decode_configs(c);
1632 
1633 	spram_config();
1634 }
1635 
1636 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
1637 {
1638 	decode_configs(c);
1639 	switch (c->processor_id & PRID_IMP_MASK) {
1640 	case PRID_IMP_AU1_REV1:
1641 	case PRID_IMP_AU1_REV2:
1642 		c->cputype = CPU_ALCHEMY;
1643 		switch ((c->processor_id >> 24) & 0xff) {
1644 		case 0:
1645 			__cpu_name[cpu] = "Au1000";
1646 			break;
1647 		case 1:
1648 			__cpu_name[cpu] = "Au1500";
1649 			break;
1650 		case 2:
1651 			__cpu_name[cpu] = "Au1100";
1652 			break;
1653 		case 3:
1654 			__cpu_name[cpu] = "Au1550";
1655 			break;
1656 		case 4:
1657 			__cpu_name[cpu] = "Au1200";
1658 			if ((c->processor_id & PRID_REV_MASK) == 2)
1659 				__cpu_name[cpu] = "Au1250";
1660 			break;
1661 		case 5:
1662 			__cpu_name[cpu] = "Au1210";
1663 			break;
1664 		default:
1665 			__cpu_name[cpu] = "Au1xxx";
1666 			break;
1667 		}
1668 		break;
1669 	}
1670 }
1671 
1672 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
1673 {
1674 	decode_configs(c);
1675 
1676 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1677 	switch (c->processor_id & PRID_IMP_MASK) {
1678 	case PRID_IMP_SB1:
1679 		c->cputype = CPU_SB1;
1680 		__cpu_name[cpu] = "SiByte SB1";
1681 		/* FPU in pass1 is known to have issues. */
1682 		if ((c->processor_id & PRID_REV_MASK) < 0x02)
1683 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
1684 		break;
1685 	case PRID_IMP_SB1A:
1686 		c->cputype = CPU_SB1A;
1687 		__cpu_name[cpu] = "SiByte SB1A";
1688 		break;
1689 	}
1690 }
1691 
1692 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
1693 {
1694 	decode_configs(c);
1695 	switch (c->processor_id & PRID_IMP_MASK) {
1696 	case PRID_IMP_SR71000:
1697 		c->cputype = CPU_SR71000;
1698 		__cpu_name[cpu] = "Sandcraft SR71000";
1699 		c->scache.ways = 8;
1700 		c->tlbsize = 64;
1701 		break;
1702 	}
1703 }
1704 
1705 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
1706 {
1707 	decode_configs(c);
1708 	switch (c->processor_id & PRID_IMP_MASK) {
1709 	case PRID_IMP_PR4450:
1710 		c->cputype = CPU_PR4450;
1711 		__cpu_name[cpu] = "Philips PR4450";
1712 		set_isa(c, MIPS_CPU_ISA_M32R1);
1713 		break;
1714 	}
1715 }
1716 
1717 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
1718 {
1719 	decode_configs(c);
1720 	switch (c->processor_id & PRID_IMP_MASK) {
1721 	case PRID_IMP_BMIPS32_REV4:
1722 	case PRID_IMP_BMIPS32_REV8:
1723 		c->cputype = CPU_BMIPS32;
1724 		__cpu_name[cpu] = "Broadcom BMIPS32";
1725 		set_elf_platform(cpu, "bmips32");
1726 		break;
1727 	case PRID_IMP_BMIPS3300:
1728 	case PRID_IMP_BMIPS3300_ALT:
1729 	case PRID_IMP_BMIPS3300_BUG:
1730 		c->cputype = CPU_BMIPS3300;
1731 		__cpu_name[cpu] = "Broadcom BMIPS3300";
1732 		set_elf_platform(cpu, "bmips3300");
1733 		break;
1734 	case PRID_IMP_BMIPS43XX: {
1735 		int rev = c->processor_id & PRID_REV_MASK;
1736 
1737 		if (rev >= PRID_REV_BMIPS4380_LO &&
1738 				rev <= PRID_REV_BMIPS4380_HI) {
1739 			c->cputype = CPU_BMIPS4380;
1740 			__cpu_name[cpu] = "Broadcom BMIPS4380";
1741 			set_elf_platform(cpu, "bmips4380");
1742 			c->options |= MIPS_CPU_RIXI;
1743 		} else {
1744 			c->cputype = CPU_BMIPS4350;
1745 			__cpu_name[cpu] = "Broadcom BMIPS4350";
1746 			set_elf_platform(cpu, "bmips4350");
1747 		}
1748 		break;
1749 	}
1750 	case PRID_IMP_BMIPS5000:
1751 	case PRID_IMP_BMIPS5200:
1752 		c->cputype = CPU_BMIPS5000;
1753 		if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_BMIPS5200)
1754 			__cpu_name[cpu] = "Broadcom BMIPS5200";
1755 		else
1756 			__cpu_name[cpu] = "Broadcom BMIPS5000";
1757 		set_elf_platform(cpu, "bmips5000");
1758 		c->options |= MIPS_CPU_ULRI | MIPS_CPU_RIXI;
1759 		break;
1760 	}
1761 }
1762 
1763 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
1764 {
1765 	decode_configs(c);
1766 	switch (c->processor_id & PRID_IMP_MASK) {
1767 	case PRID_IMP_CAVIUM_CN38XX:
1768 	case PRID_IMP_CAVIUM_CN31XX:
1769 	case PRID_IMP_CAVIUM_CN30XX:
1770 		c->cputype = CPU_CAVIUM_OCTEON;
1771 		__cpu_name[cpu] = "Cavium Octeon";
1772 		goto platform;
1773 	case PRID_IMP_CAVIUM_CN58XX:
1774 	case PRID_IMP_CAVIUM_CN56XX:
1775 	case PRID_IMP_CAVIUM_CN50XX:
1776 	case PRID_IMP_CAVIUM_CN52XX:
1777 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
1778 		__cpu_name[cpu] = "Cavium Octeon+";
1779 platform:
1780 		set_elf_platform(cpu, "octeon");
1781 		break;
1782 	case PRID_IMP_CAVIUM_CN61XX:
1783 	case PRID_IMP_CAVIUM_CN63XX:
1784 	case PRID_IMP_CAVIUM_CN66XX:
1785 	case PRID_IMP_CAVIUM_CN68XX:
1786 	case PRID_IMP_CAVIUM_CNF71XX:
1787 		c->cputype = CPU_CAVIUM_OCTEON2;
1788 		__cpu_name[cpu] = "Cavium Octeon II";
1789 		set_elf_platform(cpu, "octeon2");
1790 		break;
1791 	case PRID_IMP_CAVIUM_CN70XX:
1792 	case PRID_IMP_CAVIUM_CN73XX:
1793 	case PRID_IMP_CAVIUM_CNF75XX:
1794 	case PRID_IMP_CAVIUM_CN78XX:
1795 		c->cputype = CPU_CAVIUM_OCTEON3;
1796 		__cpu_name[cpu] = "Cavium Octeon III";
1797 		set_elf_platform(cpu, "octeon3");
1798 		break;
1799 	default:
1800 		printk(KERN_INFO "Unknown Octeon chip!\n");
1801 		c->cputype = CPU_UNKNOWN;
1802 		break;
1803 	}
1804 }
1805 
1806 static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
1807 {
1808 	switch (c->processor_id & PRID_IMP_MASK) {
1809 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1810 		switch (c->processor_id & PRID_REV_MASK) {
1811 		case PRID_REV_LOONGSON3A_R2:
1812 			c->cputype = CPU_LOONGSON3;
1813 			__cpu_name[cpu] = "ICT Loongson-3";
1814 			set_elf_platform(cpu, "loongson3a");
1815 			set_isa(c, MIPS_CPU_ISA_M64R2);
1816 			break;
1817 		}
1818 
1819 		decode_configs(c);
1820 		c->options |= MIPS_CPU_TLBINV | MIPS_CPU_LDPTE;
1821 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1822 		break;
1823 	default:
1824 		panic("Unknown Loongson Processor ID!");
1825 		break;
1826 	}
1827 }
1828 
1829 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
1830 {
1831 	decode_configs(c);
1832 	/* JZRISC does not implement the CP0 counter. */
1833 	c->options &= ~MIPS_CPU_COUNTER;
1834 	BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);
1835 	switch (c->processor_id & PRID_IMP_MASK) {
1836 	case PRID_IMP_JZRISC:
1837 		c->cputype = CPU_JZRISC;
1838 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1839 		__cpu_name[cpu] = "Ingenic JZRISC";
1840 		break;
1841 	default:
1842 		panic("Unknown Ingenic Processor ID!");
1843 		break;
1844 	}
1845 }
1846 
1847 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1848 {
1849 	decode_configs(c);
1850 
1851 	if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_NETLOGIC_AU13XX) {
1852 		c->cputype = CPU_ALCHEMY;
1853 		__cpu_name[cpu] = "Au1300";
1854 		/* following stuff is not for Alchemy */
1855 		return;
1856 	}
1857 
1858 	c->options = (MIPS_CPU_TLB	 |
1859 			MIPS_CPU_4KEX	 |
1860 			MIPS_CPU_COUNTER |
1861 			MIPS_CPU_DIVEC	 |
1862 			MIPS_CPU_WATCH	 |
1863 			MIPS_CPU_EJTAG	 |
1864 			MIPS_CPU_LLSC);
1865 
1866 	switch (c->processor_id & PRID_IMP_MASK) {
1867 	case PRID_IMP_NETLOGIC_XLP2XX:
1868 	case PRID_IMP_NETLOGIC_XLP9XX:
1869 	case PRID_IMP_NETLOGIC_XLP5XX:
1870 		c->cputype = CPU_XLP;
1871 		__cpu_name[cpu] = "Broadcom XLPII";
1872 		break;
1873 
1874 	case PRID_IMP_NETLOGIC_XLP8XX:
1875 	case PRID_IMP_NETLOGIC_XLP3XX:
1876 		c->cputype = CPU_XLP;
1877 		__cpu_name[cpu] = "Netlogic XLP";
1878 		break;
1879 
1880 	case PRID_IMP_NETLOGIC_XLR732:
1881 	case PRID_IMP_NETLOGIC_XLR716:
1882 	case PRID_IMP_NETLOGIC_XLR532:
1883 	case PRID_IMP_NETLOGIC_XLR308:
1884 	case PRID_IMP_NETLOGIC_XLR532C:
1885 	case PRID_IMP_NETLOGIC_XLR516C:
1886 	case PRID_IMP_NETLOGIC_XLR508C:
1887 	case PRID_IMP_NETLOGIC_XLR308C:
1888 		c->cputype = CPU_XLR;
1889 		__cpu_name[cpu] = "Netlogic XLR";
1890 		break;
1891 
1892 	case PRID_IMP_NETLOGIC_XLS608:
1893 	case PRID_IMP_NETLOGIC_XLS408:
1894 	case PRID_IMP_NETLOGIC_XLS404:
1895 	case PRID_IMP_NETLOGIC_XLS208:
1896 	case PRID_IMP_NETLOGIC_XLS204:
1897 	case PRID_IMP_NETLOGIC_XLS108:
1898 	case PRID_IMP_NETLOGIC_XLS104:
1899 	case PRID_IMP_NETLOGIC_XLS616B:
1900 	case PRID_IMP_NETLOGIC_XLS608B:
1901 	case PRID_IMP_NETLOGIC_XLS416B:
1902 	case PRID_IMP_NETLOGIC_XLS412B:
1903 	case PRID_IMP_NETLOGIC_XLS408B:
1904 	case PRID_IMP_NETLOGIC_XLS404B:
1905 		c->cputype = CPU_XLR;
1906 		__cpu_name[cpu] = "Netlogic XLS";
1907 		break;
1908 
1909 	default:
1910 		pr_info("Unknown Netlogic chip id [%02x]!\n",
1911 		       c->processor_id);
1912 		c->cputype = CPU_XLR;
1913 		break;
1914 	}
1915 
1916 	if (c->cputype == CPU_XLP) {
1917 		set_isa(c, MIPS_CPU_ISA_M64R2);
1918 		c->options |= (MIPS_CPU_FPU | MIPS_CPU_ULRI | MIPS_CPU_MCHECK);
1919 		/* This will be updated again after all threads are woken up */
1920 		c->tlbsize = ((read_c0_config6() >> 16) & 0xffff) + 1;
1921 	} else {
1922 		set_isa(c, MIPS_CPU_ISA_M64R1);
1923 		c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
1924 	}
1925 	c->kscratch_mask = 0xf;
1926 }
1927 
1928 #ifdef CONFIG_64BIT
1929 /* For use by uaccess.h */
1930 u64 __ua_limit;
1931 EXPORT_SYMBOL(__ua_limit);
1932 #endif
1933 
1934 const char *__cpu_name[NR_CPUS];
1935 const char *__elf_platform;
1936 
1937 void cpu_probe(void)
1938 {
1939 	struct cpuinfo_mips *c = &current_cpu_data;
1940 	unsigned int cpu = smp_processor_id();
1941 
1942 	c->processor_id = PRID_IMP_UNKNOWN;
1943 	c->fpu_id	= FPIR_IMP_NONE;
1944 	c->cputype	= CPU_UNKNOWN;
1945 	c->writecombine = _CACHE_UNCACHED;
1946 
1947 	c->fpu_csr31	= FPU_CSR_RN;
1948 	c->fpu_msk31	= FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
1949 
1950 	c->processor_id = read_c0_prid();
1951 	switch (c->processor_id & PRID_COMP_MASK) {
1952 	case PRID_COMP_LEGACY:
1953 		cpu_probe_legacy(c, cpu);
1954 		break;
1955 	case PRID_COMP_MIPS:
1956 		cpu_probe_mips(c, cpu);
1957 		break;
1958 	case PRID_COMP_ALCHEMY:
1959 		cpu_probe_alchemy(c, cpu);
1960 		break;
1961 	case PRID_COMP_SIBYTE:
1962 		cpu_probe_sibyte(c, cpu);
1963 		break;
1964 	case PRID_COMP_BROADCOM:
1965 		cpu_probe_broadcom(c, cpu);
1966 		break;
1967 	case PRID_COMP_SANDCRAFT:
1968 		cpu_probe_sandcraft(c, cpu);
1969 		break;
1970 	case PRID_COMP_NXP:
1971 		cpu_probe_nxp(c, cpu);
1972 		break;
1973 	case PRID_COMP_CAVIUM:
1974 		cpu_probe_cavium(c, cpu);
1975 		break;
1976 	case PRID_COMP_LOONGSON:
1977 		cpu_probe_loongson(c, cpu);
1978 		break;
1979 	case PRID_COMP_INGENIC_D0:
1980 	case PRID_COMP_INGENIC_D1:
1981 	case PRID_COMP_INGENIC_E1:
1982 		cpu_probe_ingenic(c, cpu);
1983 		break;
1984 	case PRID_COMP_NETLOGIC:
1985 		cpu_probe_netlogic(c, cpu);
1986 		break;
1987 	}
1988 
1989 	BUG_ON(!__cpu_name[cpu]);
1990 	BUG_ON(c->cputype == CPU_UNKNOWN);
1991 
1992 	/*
1993 	 * Platform code can force the cpu type to optimize code
1994 	 * generation. In that case be sure the cpu type is correctly
1995 	 * manually setup otherwise it could trigger some nasty bugs.
1996 	 */
1997 	BUG_ON(current_cpu_type() != c->cputype);
1998 
1999 	if (cpu_has_rixi) {
2000 		/* Enable the RIXI exceptions */
2001 		set_c0_pagegrain(PG_IEC);
2002 		back_to_back_c0_hazard();
2003 		/* Verify the IEC bit is set */
2004 		if (read_c0_pagegrain() & PG_IEC)
2005 			c->options |= MIPS_CPU_RIXIEX;
2006 	}
2007 
2008 	if (mips_fpu_disabled)
2009 		c->options &= ~MIPS_CPU_FPU;
2010 
2011 	if (mips_dsp_disabled)
2012 		c->ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
2013 
2014 	if (mips_htw_disabled) {
2015 		c->options &= ~MIPS_CPU_HTW;
2016 		write_c0_pwctl(read_c0_pwctl() &
2017 			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
2018 	}
2019 
2020 	if (c->options & MIPS_CPU_FPU)
2021 		cpu_set_fpu_opts(c);
2022 	else
2023 		cpu_set_nofpu_opts(c);
2024 
2025 	if (cpu_has_bp_ghist)
2026 		write_c0_r10k_diag(read_c0_r10k_diag() |
2027 				   R10K_DIAG_E_GHIST);
2028 
2029 	if (cpu_has_mips_r2_r6) {
2030 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
2031 		/* R2 has Performance Counter Interrupt indicator */
2032 		c->options |= MIPS_CPU_PCI;
2033 	}
2034 	else
2035 		c->srsets = 1;
2036 
2037 	if (cpu_has_mips_r6)
2038 		elf_hwcap |= HWCAP_MIPS_R6;
2039 
2040 	if (cpu_has_msa) {
2041 		c->msa_id = cpu_get_msa_id();
2042 		WARN(c->msa_id & MSA_IR_WRPF,
2043 		     "Vector register partitioning unimplemented!");
2044 		elf_hwcap |= HWCAP_MIPS_MSA;
2045 	}
2046 
2047 	if (cpu_has_vz)
2048 		cpu_probe_vz(c);
2049 
2050 	cpu_probe_vmbits(c);
2051 
2052 #ifdef CONFIG_64BIT
2053 	if (cpu == 0)
2054 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
2055 #endif
2056 }
2057 
2058 void cpu_report(void)
2059 {
2060 	struct cpuinfo_mips *c = &current_cpu_data;
2061 
2062 	pr_info("CPU%d revision is: %08x (%s)\n",
2063 		smp_processor_id(), c->processor_id, cpu_name_string());
2064 	if (c->options & MIPS_CPU_FPU)
2065 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
2066 	if (cpu_has_msa)
2067 		pr_info("MSA revision is: %08x\n", c->msa_id);
2068 }
2069