xref: /linux/arch/mips/kernel/cpu-probe.c (revision 4f4ddad395b04c051fcf76687dd558228e605b6f)
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 
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_UFRP)
293 			c->options |= MIPS_CPU_UFR;
294 		if (c->fpu_id & MIPS_FPIR_FREP)
295 			c->options |= MIPS_CPU_FRE;
296 	}
297 
298 	cpu_set_fpu_fcsr_mask(c);
299 	cpu_set_fpu_2008(c);
300 	cpu_set_nan_2008(c);
301 }
302 
303 /*
304  * Set options for the FPU emulator.
305  */
306 static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
307 {
308 	c->options &= ~MIPS_CPU_FPU;
309 	c->fpu_msk31 = mips_nofpu_msk31;
310 
311 	cpu_set_nofpu_2008(c);
312 	cpu_set_nan_2008(c);
313 	cpu_set_nofpu_id(c);
314 }
315 
316 static int mips_fpu_disabled;
317 
318 static int __init fpu_disable(char *s)
319 {
320 	cpu_set_nofpu_opts(&boot_cpu_data);
321 	mips_fpu_disabled = 1;
322 
323 	return 1;
324 }
325 
326 __setup("nofpu", fpu_disable);
327 
328 int mips_dsp_disabled;
329 
330 static int __init dsp_disable(char *s)
331 {
332 	cpu_data[0].ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
333 	mips_dsp_disabled = 1;
334 
335 	return 1;
336 }
337 
338 __setup("nodsp", dsp_disable);
339 
340 static int mips_htw_disabled;
341 
342 static int __init htw_disable(char *s)
343 {
344 	mips_htw_disabled = 1;
345 	cpu_data[0].options &= ~MIPS_CPU_HTW;
346 	write_c0_pwctl(read_c0_pwctl() &
347 		       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
348 
349 	return 1;
350 }
351 
352 __setup("nohtw", htw_disable);
353 
354 static int mips_ftlb_disabled;
355 static int mips_has_ftlb_configured;
356 
357 enum ftlb_flags {
358 	FTLB_EN		= 1 << 0,
359 	FTLB_SET_PROB	= 1 << 1,
360 };
361 
362 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags);
363 
364 static int __init ftlb_disable(char *s)
365 {
366 	unsigned int config4, mmuextdef;
367 
368 	/*
369 	 * If the core hasn't done any FTLB configuration, there is nothing
370 	 * for us to do here.
371 	 */
372 	if (!mips_has_ftlb_configured)
373 		return 1;
374 
375 	/* Disable it in the boot cpu */
376 	if (set_ftlb_enable(&cpu_data[0], 0)) {
377 		pr_warn("Can't turn FTLB off\n");
378 		return 1;
379 	}
380 
381 	config4 = read_c0_config4();
382 
383 	/* Check that FTLB has been disabled */
384 	mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
385 	/* MMUSIZEEXT == VTLB ON, FTLB OFF */
386 	if (mmuextdef == MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT) {
387 		/* This should never happen */
388 		pr_warn("FTLB could not be disabled!\n");
389 		return 1;
390 	}
391 
392 	mips_ftlb_disabled = 1;
393 	mips_has_ftlb_configured = 0;
394 
395 	/*
396 	 * noftlb is mainly used for debug purposes so print
397 	 * an informative message instead of using pr_debug()
398 	 */
399 	pr_info("FTLB has been disabled\n");
400 
401 	/*
402 	 * Some of these bits are duplicated in the decode_config4.
403 	 * MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT is the only possible case
404 	 * once FTLB has been disabled so undo what decode_config4 did.
405 	 */
406 	cpu_data[0].tlbsize -= cpu_data[0].tlbsizeftlbways *
407 			       cpu_data[0].tlbsizeftlbsets;
408 	cpu_data[0].tlbsizeftlbsets = 0;
409 	cpu_data[0].tlbsizeftlbways = 0;
410 
411 	return 1;
412 }
413 
414 __setup("noftlb", ftlb_disable);
415 
416 
417 static inline void check_errata(void)
418 {
419 	struct cpuinfo_mips *c = &current_cpu_data;
420 
421 	switch (current_cpu_type()) {
422 	case CPU_34K:
423 		/*
424 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
425 		 * This code only handles VPE0, any SMP/RTOS code
426 		 * making use of VPE1 will be responsable for that VPE.
427 		 */
428 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
429 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
430 		break;
431 	default:
432 		break;
433 	}
434 }
435 
436 void __init check_bugs32(void)
437 {
438 	check_errata();
439 }
440 
441 /*
442  * Probe whether cpu has config register by trying to play with
443  * alternate cache bit and see whether it matters.
444  * It's used by cpu_probe to distinguish between R3000A and R3081.
445  */
446 static inline int cpu_has_confreg(void)
447 {
448 #ifdef CONFIG_CPU_R3000
449 	extern unsigned long r3k_cache_size(unsigned long);
450 	unsigned long size1, size2;
451 	unsigned long cfg = read_c0_conf();
452 
453 	size1 = r3k_cache_size(ST0_ISC);
454 	write_c0_conf(cfg ^ R30XX_CONF_AC);
455 	size2 = r3k_cache_size(ST0_ISC);
456 	write_c0_conf(cfg);
457 	return size1 != size2;
458 #else
459 	return 0;
460 #endif
461 }
462 
463 static inline void set_elf_platform(int cpu, const char *plat)
464 {
465 	if (cpu == 0)
466 		__elf_platform = plat;
467 }
468 
469 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
470 {
471 #ifdef __NEED_VMBITS_PROBE
472 	write_c0_entryhi(0x3fffffffffffe000ULL);
473 	back_to_back_c0_hazard();
474 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
475 #endif
476 }
477 
478 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
479 {
480 	switch (isa) {
481 	case MIPS_CPU_ISA_M64R2:
482 		c->isa_level |= MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2;
483 	case MIPS_CPU_ISA_M64R1:
484 		c->isa_level |= MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1;
485 	case MIPS_CPU_ISA_V:
486 		c->isa_level |= MIPS_CPU_ISA_V;
487 	case MIPS_CPU_ISA_IV:
488 		c->isa_level |= MIPS_CPU_ISA_IV;
489 	case MIPS_CPU_ISA_III:
490 		c->isa_level |= MIPS_CPU_ISA_II | MIPS_CPU_ISA_III;
491 		break;
492 
493 	/* R6 incompatible with everything else */
494 	case MIPS_CPU_ISA_M64R6:
495 		c->isa_level |= MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6;
496 	case MIPS_CPU_ISA_M32R6:
497 		c->isa_level |= MIPS_CPU_ISA_M32R6;
498 		/* Break here so we don't add incompatible ISAs */
499 		break;
500 	case MIPS_CPU_ISA_M32R2:
501 		c->isa_level |= MIPS_CPU_ISA_M32R2;
502 	case MIPS_CPU_ISA_M32R1:
503 		c->isa_level |= MIPS_CPU_ISA_M32R1;
504 	case MIPS_CPU_ISA_II:
505 		c->isa_level |= MIPS_CPU_ISA_II;
506 		break;
507 	}
508 }
509 
510 static char unknown_isa[] = KERN_ERR \
511 	"Unsupported ISA type, c0.config0: %d.";
512 
513 static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
514 {
515 
516 	unsigned int probability = c->tlbsize / c->tlbsizevtlb;
517 
518 	/*
519 	 * 0 = All TLBWR instructions go to FTLB
520 	 * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
521 	 * FTLB and 1 goes to the VTLB.
522 	 * 2 = 7:1: As above with 7:1 ratio.
523 	 * 3 = 3:1: As above with 3:1 ratio.
524 	 *
525 	 * Use the linear midpoint as the probability threshold.
526 	 */
527 	if (probability >= 12)
528 		return 1;
529 	else if (probability >= 6)
530 		return 2;
531 	else
532 		/*
533 		 * So FTLB is less than 4 times bigger than VTLB.
534 		 * A 3:1 ratio can still be useful though.
535 		 */
536 		return 3;
537 }
538 
539 static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags)
540 {
541 	unsigned int config;
542 
543 	/* It's implementation dependent how the FTLB can be enabled */
544 	switch (c->cputype) {
545 	case CPU_PROAPTIV:
546 	case CPU_P5600:
547 	case CPU_P6600:
548 		/* proAptiv & related cores use Config6 to enable the FTLB */
549 		config = read_c0_config6();
550 
551 		if (flags & FTLB_EN)
552 			config |= MIPS_CONF6_FTLBEN;
553 		else
554 			config &= ~MIPS_CONF6_FTLBEN;
555 
556 		if (flags & FTLB_SET_PROB) {
557 			config &= ~(3 << MIPS_CONF6_FTLBP_SHIFT);
558 			config |= calculate_ftlb_probability(c)
559 				  << MIPS_CONF6_FTLBP_SHIFT;
560 		}
561 
562 		write_c0_config6(config);
563 		back_to_back_c0_hazard();
564 		break;
565 	case CPU_I6400:
566 		/* There's no way to disable the FTLB */
567 		if (!(flags & FTLB_EN))
568 			return 1;
569 		return 0;
570 	case CPU_LOONGSON3:
571 		/* Flush ITLB, DTLB, VTLB and FTLB */
572 		write_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB |
573 			      LOONGSON_DIAG_VTLB | LOONGSON_DIAG_FTLB);
574 		/* Loongson-3 cores use Config6 to enable the FTLB */
575 		config = read_c0_config6();
576 		if (flags & FTLB_EN)
577 			/* Enable FTLB */
578 			write_c0_config6(config & ~MIPS_CONF6_FTLBDIS);
579 		else
580 			/* Disable FTLB */
581 			write_c0_config6(config | MIPS_CONF6_FTLBDIS);
582 		break;
583 	default:
584 		return 1;
585 	}
586 
587 	return 0;
588 }
589 
590 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
591 {
592 	unsigned int config0;
593 	int isa, mt;
594 
595 	config0 = read_c0_config();
596 
597 	/*
598 	 * Look for Standard TLB or Dual VTLB and FTLB
599 	 */
600 	mt = config0 & MIPS_CONF_MT;
601 	if (mt == MIPS_CONF_MT_TLB)
602 		c->options |= MIPS_CPU_TLB;
603 	else if (mt == MIPS_CONF_MT_FTLB)
604 		c->options |= MIPS_CPU_TLB | MIPS_CPU_FTLB;
605 
606 	isa = (config0 & MIPS_CONF_AT) >> 13;
607 	switch (isa) {
608 	case 0:
609 		switch ((config0 & MIPS_CONF_AR) >> 10) {
610 		case 0:
611 			set_isa(c, MIPS_CPU_ISA_M32R1);
612 			break;
613 		case 1:
614 			set_isa(c, MIPS_CPU_ISA_M32R2);
615 			break;
616 		case 2:
617 			set_isa(c, MIPS_CPU_ISA_M32R6);
618 			break;
619 		default:
620 			goto unknown;
621 		}
622 		break;
623 	case 2:
624 		switch ((config0 & MIPS_CONF_AR) >> 10) {
625 		case 0:
626 			set_isa(c, MIPS_CPU_ISA_M64R1);
627 			break;
628 		case 1:
629 			set_isa(c, MIPS_CPU_ISA_M64R2);
630 			break;
631 		case 2:
632 			set_isa(c, MIPS_CPU_ISA_M64R6);
633 			break;
634 		default:
635 			goto unknown;
636 		}
637 		break;
638 	default:
639 		goto unknown;
640 	}
641 
642 	return config0 & MIPS_CONF_M;
643 
644 unknown:
645 	panic(unknown_isa, config0);
646 }
647 
648 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
649 {
650 	unsigned int config1;
651 
652 	config1 = read_c0_config1();
653 
654 	if (config1 & MIPS_CONF1_MD)
655 		c->ases |= MIPS_ASE_MDMX;
656 	if (config1 & MIPS_CONF1_PC)
657 		c->options |= MIPS_CPU_PERF;
658 	if (config1 & MIPS_CONF1_WR)
659 		c->options |= MIPS_CPU_WATCH;
660 	if (config1 & MIPS_CONF1_CA)
661 		c->ases |= MIPS_ASE_MIPS16;
662 	if (config1 & MIPS_CONF1_EP)
663 		c->options |= MIPS_CPU_EJTAG;
664 	if (config1 & MIPS_CONF1_FP) {
665 		c->options |= MIPS_CPU_FPU;
666 		c->options |= MIPS_CPU_32FPR;
667 	}
668 	if (cpu_has_tlb) {
669 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
670 		c->tlbsizevtlb = c->tlbsize;
671 		c->tlbsizeftlbsets = 0;
672 	}
673 
674 	return config1 & MIPS_CONF_M;
675 }
676 
677 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
678 {
679 	unsigned int config2;
680 
681 	config2 = read_c0_config2();
682 
683 	if (config2 & MIPS_CONF2_SL)
684 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
685 
686 	return config2 & MIPS_CONF_M;
687 }
688 
689 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
690 {
691 	unsigned int config3;
692 
693 	config3 = read_c0_config3();
694 
695 	if (config3 & MIPS_CONF3_SM) {
696 		c->ases |= MIPS_ASE_SMARTMIPS;
697 		c->options |= MIPS_CPU_RIXI | MIPS_CPU_CTXTC;
698 	}
699 	if (config3 & MIPS_CONF3_RXI)
700 		c->options |= MIPS_CPU_RIXI;
701 	if (config3 & MIPS_CONF3_CTXTC)
702 		c->options |= MIPS_CPU_CTXTC;
703 	if (config3 & MIPS_CONF3_DSP)
704 		c->ases |= MIPS_ASE_DSP;
705 	if (config3 & MIPS_CONF3_DSP2P) {
706 		c->ases |= MIPS_ASE_DSP2P;
707 		if (cpu_has_mips_r6)
708 			c->ases |= MIPS_ASE_DSP3;
709 	}
710 	if (config3 & MIPS_CONF3_VINT)
711 		c->options |= MIPS_CPU_VINT;
712 	if (config3 & MIPS_CONF3_VEIC)
713 		c->options |= MIPS_CPU_VEIC;
714 	if (config3 & MIPS_CONF3_LPA)
715 		c->options |= MIPS_CPU_LPA;
716 	if (config3 & MIPS_CONF3_MT)
717 		c->ases |= MIPS_ASE_MIPSMT;
718 	if (config3 & MIPS_CONF3_ULRI)
719 		c->options |= MIPS_CPU_ULRI;
720 	if (config3 & MIPS_CONF3_ISA)
721 		c->options |= MIPS_CPU_MICROMIPS;
722 	if (config3 & MIPS_CONF3_VZ)
723 		c->ases |= MIPS_ASE_VZ;
724 	if (config3 & MIPS_CONF3_SC)
725 		c->options |= MIPS_CPU_SEGMENTS;
726 	if (config3 & MIPS_CONF3_BI)
727 		c->options |= MIPS_CPU_BADINSTR;
728 	if (config3 & MIPS_CONF3_BP)
729 		c->options |= MIPS_CPU_BADINSTRP;
730 	if (config3 & MIPS_CONF3_MSA)
731 		c->ases |= MIPS_ASE_MSA;
732 	if (config3 & MIPS_CONF3_PW) {
733 		c->htw_seq = 0;
734 		c->options |= MIPS_CPU_HTW;
735 	}
736 	if (config3 & MIPS_CONF3_CDMM)
737 		c->options |= MIPS_CPU_CDMM;
738 	if (config3 & MIPS_CONF3_SP)
739 		c->options |= MIPS_CPU_SP;
740 
741 	return config3 & MIPS_CONF_M;
742 }
743 
744 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
745 {
746 	unsigned int config4;
747 	unsigned int newcf4;
748 	unsigned int mmuextdef;
749 	unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE;
750 	unsigned long asid_mask;
751 
752 	config4 = read_c0_config4();
753 
754 	if (cpu_has_tlb) {
755 		if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
756 			c->options |= MIPS_CPU_TLBINV;
757 
758 		/*
759 		 * R6 has dropped the MMUExtDef field from config4.
760 		 * On R6 the fields always describe the FTLB, and only if it is
761 		 * present according to Config.MT.
762 		 */
763 		if (!cpu_has_mips_r6)
764 			mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
765 		else if (cpu_has_ftlb)
766 			mmuextdef = MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT;
767 		else
768 			mmuextdef = 0;
769 
770 		switch (mmuextdef) {
771 		case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT:
772 			c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
773 			c->tlbsizevtlb = c->tlbsize;
774 			break;
775 		case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
776 			c->tlbsizevtlb +=
777 				((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
778 				  MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40;
779 			c->tlbsize = c->tlbsizevtlb;
780 			ftlb_page = MIPS_CONF4_VFTLBPAGESIZE;
781 			/* fall through */
782 		case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
783 			if (mips_ftlb_disabled)
784 				break;
785 			newcf4 = (config4 & ~ftlb_page) |
786 				(page_size_ftlb(mmuextdef) <<
787 				 MIPS_CONF4_FTLBPAGESIZE_SHIFT);
788 			write_c0_config4(newcf4);
789 			back_to_back_c0_hazard();
790 			config4 = read_c0_config4();
791 			if (config4 != newcf4) {
792 				pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n",
793 				       PAGE_SIZE, config4);
794 				/* Switch FTLB off */
795 				set_ftlb_enable(c, 0);
796 				mips_ftlb_disabled = 1;
797 				break;
798 			}
799 			c->tlbsizeftlbsets = 1 <<
800 				((config4 & MIPS_CONF4_FTLBSETS) >>
801 				 MIPS_CONF4_FTLBSETS_SHIFT);
802 			c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >>
803 					      MIPS_CONF4_FTLBWAYS_SHIFT) + 2;
804 			c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets;
805 			mips_has_ftlb_configured = 1;
806 			break;
807 		}
808 	}
809 
810 	c->kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
811 				>> MIPS_CONF4_KSCREXIST_SHIFT;
812 
813 	asid_mask = MIPS_ENTRYHI_ASID;
814 	if (config4 & MIPS_CONF4_AE)
815 		asid_mask |= MIPS_ENTRYHI_ASIDX;
816 	set_cpu_asid_mask(c, asid_mask);
817 
818 	/*
819 	 * Warn if the computed ASID mask doesn't match the mask the kernel
820 	 * is built for. This may indicate either a serious problem or an
821 	 * easy optimisation opportunity, but either way should be addressed.
822 	 */
823 	WARN_ON(asid_mask != cpu_asid_mask(c));
824 
825 	return config4 & MIPS_CONF_M;
826 }
827 
828 static inline unsigned int decode_config5(struct cpuinfo_mips *c)
829 {
830 	unsigned int config5;
831 
832 	config5 = read_c0_config5();
833 	config5 &= ~(MIPS_CONF5_UFR | MIPS_CONF5_UFE);
834 	write_c0_config5(config5);
835 
836 	if (config5 & MIPS_CONF5_EVA)
837 		c->options |= MIPS_CPU_EVA;
838 	if (config5 & MIPS_CONF5_MRP)
839 		c->options |= MIPS_CPU_MAAR;
840 	if (config5 & MIPS_CONF5_LLB)
841 		c->options |= MIPS_CPU_RW_LLB;
842 	if (config5 & MIPS_CONF5_MVH)
843 		c->options |= MIPS_CPU_MVH;
844 	if (cpu_has_mips_r6 && (config5 & MIPS_CONF5_VP))
845 		c->options |= MIPS_CPU_VP;
846 
847 	return config5 & MIPS_CONF_M;
848 }
849 
850 static void decode_configs(struct cpuinfo_mips *c)
851 {
852 	int ok;
853 
854 	/* MIPS32 or MIPS64 compliant CPU.  */
855 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
856 		     MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
857 
858 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
859 
860 	/* Enable FTLB if present and not disabled */
861 	set_ftlb_enable(c, mips_ftlb_disabled ? 0 : FTLB_EN);
862 
863 	ok = decode_config0(c);			/* Read Config registers.  */
864 	BUG_ON(!ok);				/* Arch spec violation!	 */
865 	if (ok)
866 		ok = decode_config1(c);
867 	if (ok)
868 		ok = decode_config2(c);
869 	if (ok)
870 		ok = decode_config3(c);
871 	if (ok)
872 		ok = decode_config4(c);
873 	if (ok)
874 		ok = decode_config5(c);
875 
876 	/* Probe the EBase.WG bit */
877 	if (cpu_has_mips_r2_r6) {
878 		u64 ebase;
879 		unsigned int status;
880 
881 		/* {read,write}_c0_ebase_64() may be UNDEFINED prior to r6 */
882 		ebase = cpu_has_mips64r6 ? read_c0_ebase_64()
883 					 : (s32)read_c0_ebase();
884 		if (ebase & MIPS_EBASE_WG) {
885 			/* WG bit already set, we can avoid the clumsy probe */
886 			c->options |= MIPS_CPU_EBASE_WG;
887 		} else {
888 			/* Its UNDEFINED to change EBase while BEV=0 */
889 			status = read_c0_status();
890 			write_c0_status(status | ST0_BEV);
891 			irq_enable_hazard();
892 			/*
893 			 * On pre-r6 cores, this may well clobber the upper bits
894 			 * of EBase. This is hard to avoid without potentially
895 			 * hitting UNDEFINED dm*c0 behaviour if EBase is 32-bit.
896 			 */
897 			if (cpu_has_mips64r6)
898 				write_c0_ebase_64(ebase | MIPS_EBASE_WG);
899 			else
900 				write_c0_ebase(ebase | MIPS_EBASE_WG);
901 			back_to_back_c0_hazard();
902 			/* Restore BEV */
903 			write_c0_status(status);
904 			if (read_c0_ebase() & MIPS_EBASE_WG) {
905 				c->options |= MIPS_CPU_EBASE_WG;
906 				write_c0_ebase(ebase);
907 			}
908 		}
909 	}
910 
911 	/* configure the FTLB write probability */
912 	set_ftlb_enable(c, (mips_ftlb_disabled ? 0 : FTLB_EN) | FTLB_SET_PROB);
913 
914 	mips_probe_watch_registers(c);
915 
916 #ifndef CONFIG_MIPS_CPS
917 	if (cpu_has_mips_r2_r6) {
918 		c->core = get_ebase_cpunum();
919 		if (cpu_has_mipsmt)
920 			c->core >>= fls(core_nvpes()) - 1;
921 	}
922 #endif
923 }
924 
925 /*
926  * Probe for certain guest capabilities by writing config bits and reading back.
927  * Finally write back the original value.
928  */
929 #define probe_gc0_config(name, maxconf, bits)				\
930 do {									\
931 	unsigned int tmp;						\
932 	tmp = read_gc0_##name();					\
933 	write_gc0_##name(tmp | (bits));					\
934 	back_to_back_c0_hazard();					\
935 	maxconf = read_gc0_##name();					\
936 	write_gc0_##name(tmp);						\
937 } while (0)
938 
939 /*
940  * Probe for dynamic guest capabilities by changing certain config bits and
941  * reading back to see if they change. Finally write back the original value.
942  */
943 #define probe_gc0_config_dyn(name, maxconf, dynconf, bits)		\
944 do {									\
945 	maxconf = read_gc0_##name();					\
946 	write_gc0_##name(maxconf ^ (bits));				\
947 	back_to_back_c0_hazard();					\
948 	dynconf = maxconf ^ read_gc0_##name();				\
949 	write_gc0_##name(maxconf);					\
950 	maxconf |= dynconf;						\
951 } while (0)
952 
953 static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c)
954 {
955 	unsigned int config0;
956 
957 	probe_gc0_config(config, config0, MIPS_CONF_M);
958 
959 	if (config0 & MIPS_CONF_M)
960 		c->guest.conf |= BIT(1);
961 	return config0 & MIPS_CONF_M;
962 }
963 
964 static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c)
965 {
966 	unsigned int config1, config1_dyn;
967 
968 	probe_gc0_config_dyn(config1, config1, config1_dyn,
969 			     MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR |
970 			     MIPS_CONF1_FP);
971 
972 	if (config1 & MIPS_CONF1_FP)
973 		c->guest.options |= MIPS_CPU_FPU;
974 	if (config1_dyn & MIPS_CONF1_FP)
975 		c->guest.options_dyn |= MIPS_CPU_FPU;
976 
977 	if (config1 & MIPS_CONF1_WR)
978 		c->guest.options |= MIPS_CPU_WATCH;
979 	if (config1_dyn & MIPS_CONF1_WR)
980 		c->guest.options_dyn |= MIPS_CPU_WATCH;
981 
982 	if (config1 & MIPS_CONF1_PC)
983 		c->guest.options |= MIPS_CPU_PERF;
984 	if (config1_dyn & MIPS_CONF1_PC)
985 		c->guest.options_dyn |= MIPS_CPU_PERF;
986 
987 	if (config1 & MIPS_CONF_M)
988 		c->guest.conf |= BIT(2);
989 	return config1 & MIPS_CONF_M;
990 }
991 
992 static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c)
993 {
994 	unsigned int config2;
995 
996 	probe_gc0_config(config2, config2, MIPS_CONF_M);
997 
998 	if (config2 & MIPS_CONF_M)
999 		c->guest.conf |= BIT(3);
1000 	return config2 & MIPS_CONF_M;
1001 }
1002 
1003 static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c)
1004 {
1005 	unsigned int config3, config3_dyn;
1006 
1007 	probe_gc0_config_dyn(config3, config3, config3_dyn,
1008 			     MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_ULRI |
1009 			     MIPS_CONF3_CTXTC);
1010 
1011 	if (config3 & MIPS_CONF3_CTXTC)
1012 		c->guest.options |= MIPS_CPU_CTXTC;
1013 	if (config3_dyn & MIPS_CONF3_CTXTC)
1014 		c->guest.options_dyn |= MIPS_CPU_CTXTC;
1015 
1016 	if (config3 & MIPS_CONF3_PW)
1017 		c->guest.options |= MIPS_CPU_HTW;
1018 
1019 	if (config3 & MIPS_CONF3_ULRI)
1020 		c->guest.options |= MIPS_CPU_ULRI;
1021 
1022 	if (config3 & MIPS_CONF3_SC)
1023 		c->guest.options |= MIPS_CPU_SEGMENTS;
1024 
1025 	if (config3 & MIPS_CONF3_BI)
1026 		c->guest.options |= MIPS_CPU_BADINSTR;
1027 	if (config3 & MIPS_CONF3_BP)
1028 		c->guest.options |= MIPS_CPU_BADINSTRP;
1029 
1030 	if (config3 & MIPS_CONF3_MSA)
1031 		c->guest.ases |= MIPS_ASE_MSA;
1032 	if (config3_dyn & MIPS_CONF3_MSA)
1033 		c->guest.ases_dyn |= MIPS_ASE_MSA;
1034 
1035 	if (config3 & MIPS_CONF_M)
1036 		c->guest.conf |= BIT(4);
1037 	return config3 & MIPS_CONF_M;
1038 }
1039 
1040 static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c)
1041 {
1042 	unsigned int config4;
1043 
1044 	probe_gc0_config(config4, config4,
1045 			 MIPS_CONF_M | MIPS_CONF4_KSCREXIST);
1046 
1047 	c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
1048 				>> MIPS_CONF4_KSCREXIST_SHIFT;
1049 
1050 	if (config4 & MIPS_CONF_M)
1051 		c->guest.conf |= BIT(5);
1052 	return config4 & MIPS_CONF_M;
1053 }
1054 
1055 static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c)
1056 {
1057 	unsigned int config5, config5_dyn;
1058 
1059 	probe_gc0_config_dyn(config5, config5, config5_dyn,
1060 			 MIPS_CONF_M | MIPS_CONF5_MVH | MIPS_CONF5_MRP);
1061 
1062 	if (config5 & MIPS_CONF5_MRP)
1063 		c->guest.options |= MIPS_CPU_MAAR;
1064 	if (config5_dyn & MIPS_CONF5_MRP)
1065 		c->guest.options_dyn |= MIPS_CPU_MAAR;
1066 
1067 	if (config5 & MIPS_CONF5_LLB)
1068 		c->guest.options |= MIPS_CPU_RW_LLB;
1069 
1070 	if (config5 & MIPS_CONF5_MVH)
1071 		c->guest.options |= MIPS_CPU_MVH;
1072 
1073 	if (config5 & MIPS_CONF_M)
1074 		c->guest.conf |= BIT(6);
1075 	return config5 & MIPS_CONF_M;
1076 }
1077 
1078 static inline void decode_guest_configs(struct cpuinfo_mips *c)
1079 {
1080 	unsigned int ok;
1081 
1082 	ok = decode_guest_config0(c);
1083 	if (ok)
1084 		ok = decode_guest_config1(c);
1085 	if (ok)
1086 		ok = decode_guest_config2(c);
1087 	if (ok)
1088 		ok = decode_guest_config3(c);
1089 	if (ok)
1090 		ok = decode_guest_config4(c);
1091 	if (ok)
1092 		decode_guest_config5(c);
1093 }
1094 
1095 static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c)
1096 {
1097 	unsigned int guestctl0, temp;
1098 
1099 	guestctl0 = read_c0_guestctl0();
1100 
1101 	if (guestctl0 & MIPS_GCTL0_G0E)
1102 		c->options |= MIPS_CPU_GUESTCTL0EXT;
1103 	if (guestctl0 & MIPS_GCTL0_G1)
1104 		c->options |= MIPS_CPU_GUESTCTL1;
1105 	if (guestctl0 & MIPS_GCTL0_G2)
1106 		c->options |= MIPS_CPU_GUESTCTL2;
1107 	if (!(guestctl0 & MIPS_GCTL0_RAD)) {
1108 		c->options |= MIPS_CPU_GUESTID;
1109 
1110 		/*
1111 		 * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0
1112 		 * first, otherwise all data accesses will be fully virtualised
1113 		 * as if they were performed by guest mode.
1114 		 */
1115 		write_c0_guestctl1(0);
1116 		tlbw_use_hazard();
1117 
1118 		write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG);
1119 		back_to_back_c0_hazard();
1120 		temp = read_c0_guestctl0();
1121 
1122 		if (temp & MIPS_GCTL0_DRG) {
1123 			write_c0_guestctl0(guestctl0);
1124 			c->options |= MIPS_CPU_DRG;
1125 		}
1126 	}
1127 }
1128 
1129 static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c)
1130 {
1131 	if (cpu_has_guestid) {
1132 		/* determine the number of bits of GuestID available */
1133 		write_c0_guestctl1(MIPS_GCTL1_ID);
1134 		back_to_back_c0_hazard();
1135 		c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID)
1136 						>> MIPS_GCTL1_ID_SHIFT;
1137 		write_c0_guestctl1(0);
1138 	}
1139 }
1140 
1141 static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c)
1142 {
1143 	/* determine the number of bits of GTOffset available */
1144 	write_c0_gtoffset(0xffffffff);
1145 	back_to_back_c0_hazard();
1146 	c->gtoffset_mask = read_c0_gtoffset();
1147 	write_c0_gtoffset(0);
1148 }
1149 
1150 static inline void cpu_probe_vz(struct cpuinfo_mips *c)
1151 {
1152 	cpu_probe_guestctl0(c);
1153 	if (cpu_has_guestctl1)
1154 		cpu_probe_guestctl1(c);
1155 
1156 	cpu_probe_gtoffset(c);
1157 
1158 	decode_guest_configs(c);
1159 }
1160 
1161 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
1162 		| MIPS_CPU_COUNTER)
1163 
1164 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
1165 {
1166 	switch (c->processor_id & PRID_IMP_MASK) {
1167 	case PRID_IMP_R2000:
1168 		c->cputype = CPU_R2000;
1169 		__cpu_name[cpu] = "R2000";
1170 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1171 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1172 			     MIPS_CPU_NOFPUEX;
1173 		if (__cpu_has_fpu())
1174 			c->options |= MIPS_CPU_FPU;
1175 		c->tlbsize = 64;
1176 		break;
1177 	case PRID_IMP_R3000:
1178 		if ((c->processor_id & PRID_REV_MASK) == PRID_REV_R3000A) {
1179 			if (cpu_has_confreg()) {
1180 				c->cputype = CPU_R3081E;
1181 				__cpu_name[cpu] = "R3081";
1182 			} else {
1183 				c->cputype = CPU_R3000A;
1184 				__cpu_name[cpu] = "R3000A";
1185 			}
1186 		} else {
1187 			c->cputype = CPU_R3000;
1188 			__cpu_name[cpu] = "R3000";
1189 		}
1190 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1191 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
1192 			     MIPS_CPU_NOFPUEX;
1193 		if (__cpu_has_fpu())
1194 			c->options |= MIPS_CPU_FPU;
1195 		c->tlbsize = 64;
1196 		break;
1197 	case PRID_IMP_R4000:
1198 		if (read_c0_config() & CONF_SC) {
1199 			if ((c->processor_id & PRID_REV_MASK) >=
1200 			    PRID_REV_R4400) {
1201 				c->cputype = CPU_R4400PC;
1202 				__cpu_name[cpu] = "R4400PC";
1203 			} else {
1204 				c->cputype = CPU_R4000PC;
1205 				__cpu_name[cpu] = "R4000PC";
1206 			}
1207 		} else {
1208 			int cca = read_c0_config() & CONF_CM_CMASK;
1209 			int mc;
1210 
1211 			/*
1212 			 * SC and MC versions can't be reliably told apart,
1213 			 * but only the latter support coherent caching
1214 			 * modes so assume the firmware has set the KSEG0
1215 			 * coherency attribute reasonably (if uncached, we
1216 			 * assume SC).
1217 			 */
1218 			switch (cca) {
1219 			case CONF_CM_CACHABLE_CE:
1220 			case CONF_CM_CACHABLE_COW:
1221 			case CONF_CM_CACHABLE_CUW:
1222 				mc = 1;
1223 				break;
1224 			default:
1225 				mc = 0;
1226 				break;
1227 			}
1228 			if ((c->processor_id & PRID_REV_MASK) >=
1229 			    PRID_REV_R4400) {
1230 				c->cputype = mc ? CPU_R4400MC : CPU_R4400SC;
1231 				__cpu_name[cpu] = mc ? "R4400MC" : "R4400SC";
1232 			} else {
1233 				c->cputype = mc ? CPU_R4000MC : CPU_R4000SC;
1234 				__cpu_name[cpu] = mc ? "R4000MC" : "R4000SC";
1235 			}
1236 		}
1237 
1238 		set_isa(c, MIPS_CPU_ISA_III);
1239 		c->fpu_msk31 |= FPU_CSR_CONDX;
1240 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1241 			     MIPS_CPU_WATCH | MIPS_CPU_VCE |
1242 			     MIPS_CPU_LLSC;
1243 		c->tlbsize = 48;
1244 		break;
1245 	case PRID_IMP_VR41XX:
1246 		set_isa(c, MIPS_CPU_ISA_III);
1247 		c->fpu_msk31 |= FPU_CSR_CONDX;
1248 		c->options = R4K_OPTS;
1249 		c->tlbsize = 32;
1250 		switch (c->processor_id & 0xf0) {
1251 		case PRID_REV_VR4111:
1252 			c->cputype = CPU_VR4111;
1253 			__cpu_name[cpu] = "NEC VR4111";
1254 			break;
1255 		case PRID_REV_VR4121:
1256 			c->cputype = CPU_VR4121;
1257 			__cpu_name[cpu] = "NEC VR4121";
1258 			break;
1259 		case PRID_REV_VR4122:
1260 			if ((c->processor_id & 0xf) < 0x3) {
1261 				c->cputype = CPU_VR4122;
1262 				__cpu_name[cpu] = "NEC VR4122";
1263 			} else {
1264 				c->cputype = CPU_VR4181A;
1265 				__cpu_name[cpu] = "NEC VR4181A";
1266 			}
1267 			break;
1268 		case PRID_REV_VR4130:
1269 			if ((c->processor_id & 0xf) < 0x4) {
1270 				c->cputype = CPU_VR4131;
1271 				__cpu_name[cpu] = "NEC VR4131";
1272 			} else {
1273 				c->cputype = CPU_VR4133;
1274 				c->options |= MIPS_CPU_LLSC;
1275 				__cpu_name[cpu] = "NEC VR4133";
1276 			}
1277 			break;
1278 		default:
1279 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
1280 			c->cputype = CPU_VR41XX;
1281 			__cpu_name[cpu] = "NEC Vr41xx";
1282 			break;
1283 		}
1284 		break;
1285 	case PRID_IMP_R4300:
1286 		c->cputype = CPU_R4300;
1287 		__cpu_name[cpu] = "R4300";
1288 		set_isa(c, MIPS_CPU_ISA_III);
1289 		c->fpu_msk31 |= FPU_CSR_CONDX;
1290 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1291 			     MIPS_CPU_LLSC;
1292 		c->tlbsize = 32;
1293 		break;
1294 	case PRID_IMP_R4600:
1295 		c->cputype = CPU_R4600;
1296 		__cpu_name[cpu] = "R4600";
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_32FPR |
1300 			     MIPS_CPU_LLSC;
1301 		c->tlbsize = 48;
1302 		break;
1303 	#if 0
1304 	case PRID_IMP_R4650:
1305 		/*
1306 		 * This processor doesn't have an MMU, so it's not
1307 		 * "real easy" to run Linux on it. It is left purely
1308 		 * for documentation.  Commented out because it shares
1309 		 * it's c0_prid id number with the TX3900.
1310 		 */
1311 		c->cputype = CPU_R4650;
1312 		__cpu_name[cpu] = "R4650";
1313 		set_isa(c, MIPS_CPU_ISA_III);
1314 		c->fpu_msk31 |= FPU_CSR_CONDX;
1315 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
1316 		c->tlbsize = 48;
1317 		break;
1318 	#endif
1319 	case PRID_IMP_TX39:
1320 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1321 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
1322 
1323 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
1324 			c->cputype = CPU_TX3927;
1325 			__cpu_name[cpu] = "TX3927";
1326 			c->tlbsize = 64;
1327 		} else {
1328 			switch (c->processor_id & PRID_REV_MASK) {
1329 			case PRID_REV_TX3912:
1330 				c->cputype = CPU_TX3912;
1331 				__cpu_name[cpu] = "TX3912";
1332 				c->tlbsize = 32;
1333 				break;
1334 			case PRID_REV_TX3922:
1335 				c->cputype = CPU_TX3922;
1336 				__cpu_name[cpu] = "TX3922";
1337 				c->tlbsize = 64;
1338 				break;
1339 			}
1340 		}
1341 		break;
1342 	case PRID_IMP_R4700:
1343 		c->cputype = CPU_R4700;
1344 		__cpu_name[cpu] = "R4700";
1345 		set_isa(c, MIPS_CPU_ISA_III);
1346 		c->fpu_msk31 |= FPU_CSR_CONDX;
1347 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1348 			     MIPS_CPU_LLSC;
1349 		c->tlbsize = 48;
1350 		break;
1351 	case PRID_IMP_TX49:
1352 		c->cputype = CPU_TX49XX;
1353 		__cpu_name[cpu] = "R49XX";
1354 		set_isa(c, MIPS_CPU_ISA_III);
1355 		c->fpu_msk31 |= FPU_CSR_CONDX;
1356 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
1357 		if (!(c->processor_id & 0x08))
1358 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
1359 		c->tlbsize = 48;
1360 		break;
1361 	case PRID_IMP_R5000:
1362 		c->cputype = CPU_R5000;
1363 		__cpu_name[cpu] = "R5000";
1364 		set_isa(c, MIPS_CPU_ISA_IV);
1365 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1366 			     MIPS_CPU_LLSC;
1367 		c->tlbsize = 48;
1368 		break;
1369 	case PRID_IMP_R5432:
1370 		c->cputype = CPU_R5432;
1371 		__cpu_name[cpu] = "R5432";
1372 		set_isa(c, MIPS_CPU_ISA_IV);
1373 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1374 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1375 		c->tlbsize = 48;
1376 		break;
1377 	case PRID_IMP_R5500:
1378 		c->cputype = CPU_R5500;
1379 		__cpu_name[cpu] = "R5500";
1380 		set_isa(c, MIPS_CPU_ISA_IV);
1381 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1382 			     MIPS_CPU_WATCH | MIPS_CPU_LLSC;
1383 		c->tlbsize = 48;
1384 		break;
1385 	case PRID_IMP_NEVADA:
1386 		c->cputype = CPU_NEVADA;
1387 		__cpu_name[cpu] = "Nevada";
1388 		set_isa(c, MIPS_CPU_ISA_IV);
1389 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1390 			     MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
1391 		c->tlbsize = 48;
1392 		break;
1393 	case PRID_IMP_R6000:
1394 		c->cputype = CPU_R6000;
1395 		__cpu_name[cpu] = "R6000";
1396 		set_isa(c, MIPS_CPU_ISA_II);
1397 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1398 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
1399 			     MIPS_CPU_LLSC;
1400 		c->tlbsize = 32;
1401 		break;
1402 	case PRID_IMP_R6000A:
1403 		c->cputype = CPU_R6000A;
1404 		__cpu_name[cpu] = "R6000A";
1405 		set_isa(c, MIPS_CPU_ISA_II);
1406 		c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
1407 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
1408 			     MIPS_CPU_LLSC;
1409 		c->tlbsize = 32;
1410 		break;
1411 	case PRID_IMP_RM7000:
1412 		c->cputype = CPU_RM7000;
1413 		__cpu_name[cpu] = "RM7000";
1414 		set_isa(c, MIPS_CPU_ISA_IV);
1415 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
1416 			     MIPS_CPU_LLSC;
1417 		/*
1418 		 * Undocumented RM7000:	 Bit 29 in the info register of
1419 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
1420 		 * entries.
1421 		 *
1422 		 * 29	   1 =>	   64 entry JTLB
1423 		 *	   0 =>	   48 entry JTLB
1424 		 */
1425 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
1426 		break;
1427 	case PRID_IMP_R8000:
1428 		c->cputype = CPU_R8000;
1429 		__cpu_name[cpu] = "RM8000";
1430 		set_isa(c, MIPS_CPU_ISA_IV);
1431 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
1432 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1433 			     MIPS_CPU_LLSC;
1434 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
1435 		break;
1436 	case PRID_IMP_R10000:
1437 		c->cputype = CPU_R10000;
1438 		__cpu_name[cpu] = "R10000";
1439 		set_isa(c, MIPS_CPU_ISA_IV);
1440 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1441 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1442 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1443 			     MIPS_CPU_LLSC;
1444 		c->tlbsize = 64;
1445 		break;
1446 	case PRID_IMP_R12000:
1447 		c->cputype = CPU_R12000;
1448 		__cpu_name[cpu] = "R12000";
1449 		set_isa(c, MIPS_CPU_ISA_IV);
1450 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1451 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1452 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1453 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1454 		c->tlbsize = 64;
1455 		break;
1456 	case PRID_IMP_R14000:
1457 		if (((c->processor_id >> 4) & 0x0f) > 2) {
1458 			c->cputype = CPU_R16000;
1459 			__cpu_name[cpu] = "R16000";
1460 		} else {
1461 			c->cputype = CPU_R14000;
1462 			__cpu_name[cpu] = "R14000";
1463 		}
1464 		set_isa(c, MIPS_CPU_ISA_IV);
1465 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
1466 			     MIPS_CPU_FPU | MIPS_CPU_32FPR |
1467 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
1468 			     MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
1469 		c->tlbsize = 64;
1470 		break;
1471 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1472 		switch (c->processor_id & PRID_REV_MASK) {
1473 		case PRID_REV_LOONGSON2E:
1474 			c->cputype = CPU_LOONGSON2;
1475 			__cpu_name[cpu] = "ICT Loongson-2";
1476 			set_elf_platform(cpu, "loongson2e");
1477 			set_isa(c, MIPS_CPU_ISA_III);
1478 			c->fpu_msk31 |= FPU_CSR_CONDX;
1479 			break;
1480 		case PRID_REV_LOONGSON2F:
1481 			c->cputype = CPU_LOONGSON2;
1482 			__cpu_name[cpu] = "ICT Loongson-2";
1483 			set_elf_platform(cpu, "loongson2f");
1484 			set_isa(c, MIPS_CPU_ISA_III);
1485 			c->fpu_msk31 |= FPU_CSR_CONDX;
1486 			break;
1487 		case PRID_REV_LOONGSON3A_R1:
1488 			c->cputype = CPU_LOONGSON3;
1489 			__cpu_name[cpu] = "ICT Loongson-3";
1490 			set_elf_platform(cpu, "loongson3a");
1491 			set_isa(c, MIPS_CPU_ISA_M64R1);
1492 			break;
1493 		case PRID_REV_LOONGSON3B_R1:
1494 		case PRID_REV_LOONGSON3B_R2:
1495 			c->cputype = CPU_LOONGSON3;
1496 			__cpu_name[cpu] = "ICT Loongson-3";
1497 			set_elf_platform(cpu, "loongson3b");
1498 			set_isa(c, MIPS_CPU_ISA_M64R1);
1499 			break;
1500 		}
1501 
1502 		c->options = R4K_OPTS |
1503 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
1504 			     MIPS_CPU_32FPR;
1505 		c->tlbsize = 64;
1506 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1507 		break;
1508 	case PRID_IMP_LOONGSON_32:  /* Loongson-1 */
1509 		decode_configs(c);
1510 
1511 		c->cputype = CPU_LOONGSON1;
1512 
1513 		switch (c->processor_id & PRID_REV_MASK) {
1514 		case PRID_REV_LOONGSON1B:
1515 			__cpu_name[cpu] = "Loongson 1B";
1516 			break;
1517 		}
1518 
1519 		break;
1520 	}
1521 }
1522 
1523 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
1524 {
1525 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1526 	switch (c->processor_id & PRID_IMP_MASK) {
1527 	case PRID_IMP_QEMU_GENERIC:
1528 		c->writecombine = _CACHE_UNCACHED;
1529 		c->cputype = CPU_QEMU_GENERIC;
1530 		__cpu_name[cpu] = "MIPS GENERIC QEMU";
1531 		break;
1532 	case PRID_IMP_4KC:
1533 		c->cputype = CPU_4KC;
1534 		c->writecombine = _CACHE_UNCACHED;
1535 		__cpu_name[cpu] = "MIPS 4Kc";
1536 		break;
1537 	case PRID_IMP_4KEC:
1538 	case PRID_IMP_4KECR2:
1539 		c->cputype = CPU_4KEC;
1540 		c->writecombine = _CACHE_UNCACHED;
1541 		__cpu_name[cpu] = "MIPS 4KEc";
1542 		break;
1543 	case PRID_IMP_4KSC:
1544 	case PRID_IMP_4KSD:
1545 		c->cputype = CPU_4KSC;
1546 		c->writecombine = _CACHE_UNCACHED;
1547 		__cpu_name[cpu] = "MIPS 4KSc";
1548 		break;
1549 	case PRID_IMP_5KC:
1550 		c->cputype = CPU_5KC;
1551 		c->writecombine = _CACHE_UNCACHED;
1552 		__cpu_name[cpu] = "MIPS 5Kc";
1553 		break;
1554 	case PRID_IMP_5KE:
1555 		c->cputype = CPU_5KE;
1556 		c->writecombine = _CACHE_UNCACHED;
1557 		__cpu_name[cpu] = "MIPS 5KE";
1558 		break;
1559 	case PRID_IMP_20KC:
1560 		c->cputype = CPU_20KC;
1561 		c->writecombine = _CACHE_UNCACHED;
1562 		__cpu_name[cpu] = "MIPS 20Kc";
1563 		break;
1564 	case PRID_IMP_24K:
1565 		c->cputype = CPU_24K;
1566 		c->writecombine = _CACHE_UNCACHED;
1567 		__cpu_name[cpu] = "MIPS 24Kc";
1568 		break;
1569 	case PRID_IMP_24KE:
1570 		c->cputype = CPU_24K;
1571 		c->writecombine = _CACHE_UNCACHED;
1572 		__cpu_name[cpu] = "MIPS 24KEc";
1573 		break;
1574 	case PRID_IMP_25KF:
1575 		c->cputype = CPU_25KF;
1576 		c->writecombine = _CACHE_UNCACHED;
1577 		__cpu_name[cpu] = "MIPS 25Kc";
1578 		break;
1579 	case PRID_IMP_34K:
1580 		c->cputype = CPU_34K;
1581 		c->writecombine = _CACHE_UNCACHED;
1582 		__cpu_name[cpu] = "MIPS 34Kc";
1583 		break;
1584 	case PRID_IMP_74K:
1585 		c->cputype = CPU_74K;
1586 		c->writecombine = _CACHE_UNCACHED;
1587 		__cpu_name[cpu] = "MIPS 74Kc";
1588 		break;
1589 	case PRID_IMP_M14KC:
1590 		c->cputype = CPU_M14KC;
1591 		c->writecombine = _CACHE_UNCACHED;
1592 		__cpu_name[cpu] = "MIPS M14Kc";
1593 		break;
1594 	case PRID_IMP_M14KEC:
1595 		c->cputype = CPU_M14KEC;
1596 		c->writecombine = _CACHE_UNCACHED;
1597 		__cpu_name[cpu] = "MIPS M14KEc";
1598 		break;
1599 	case PRID_IMP_1004K:
1600 		c->cputype = CPU_1004K;
1601 		c->writecombine = _CACHE_UNCACHED;
1602 		__cpu_name[cpu] = "MIPS 1004Kc";
1603 		break;
1604 	case PRID_IMP_1074K:
1605 		c->cputype = CPU_1074K;
1606 		c->writecombine = _CACHE_UNCACHED;
1607 		__cpu_name[cpu] = "MIPS 1074Kc";
1608 		break;
1609 	case PRID_IMP_INTERAPTIV_UP:
1610 		c->cputype = CPU_INTERAPTIV;
1611 		__cpu_name[cpu] = "MIPS interAptiv";
1612 		break;
1613 	case PRID_IMP_INTERAPTIV_MP:
1614 		c->cputype = CPU_INTERAPTIV;
1615 		__cpu_name[cpu] = "MIPS interAptiv (multi)";
1616 		break;
1617 	case PRID_IMP_PROAPTIV_UP:
1618 		c->cputype = CPU_PROAPTIV;
1619 		__cpu_name[cpu] = "MIPS proAptiv";
1620 		break;
1621 	case PRID_IMP_PROAPTIV_MP:
1622 		c->cputype = CPU_PROAPTIV;
1623 		__cpu_name[cpu] = "MIPS proAptiv (multi)";
1624 		break;
1625 	case PRID_IMP_P5600:
1626 		c->cputype = CPU_P5600;
1627 		__cpu_name[cpu] = "MIPS P5600";
1628 		break;
1629 	case PRID_IMP_P6600:
1630 		c->cputype = CPU_P6600;
1631 		__cpu_name[cpu] = "MIPS P6600";
1632 		break;
1633 	case PRID_IMP_I6400:
1634 		c->cputype = CPU_I6400;
1635 		__cpu_name[cpu] = "MIPS I6400";
1636 		break;
1637 	case PRID_IMP_M5150:
1638 		c->cputype = CPU_M5150;
1639 		__cpu_name[cpu] = "MIPS M5150";
1640 		break;
1641 	case PRID_IMP_M6250:
1642 		c->cputype = CPU_M6250;
1643 		__cpu_name[cpu] = "MIPS M6250";
1644 		break;
1645 	}
1646 
1647 	decode_configs(c);
1648 
1649 	spram_config();
1650 }
1651 
1652 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
1653 {
1654 	decode_configs(c);
1655 	switch (c->processor_id & PRID_IMP_MASK) {
1656 	case PRID_IMP_AU1_REV1:
1657 	case PRID_IMP_AU1_REV2:
1658 		c->cputype = CPU_ALCHEMY;
1659 		switch ((c->processor_id >> 24) & 0xff) {
1660 		case 0:
1661 			__cpu_name[cpu] = "Au1000";
1662 			break;
1663 		case 1:
1664 			__cpu_name[cpu] = "Au1500";
1665 			break;
1666 		case 2:
1667 			__cpu_name[cpu] = "Au1100";
1668 			break;
1669 		case 3:
1670 			__cpu_name[cpu] = "Au1550";
1671 			break;
1672 		case 4:
1673 			__cpu_name[cpu] = "Au1200";
1674 			if ((c->processor_id & PRID_REV_MASK) == 2)
1675 				__cpu_name[cpu] = "Au1250";
1676 			break;
1677 		case 5:
1678 			__cpu_name[cpu] = "Au1210";
1679 			break;
1680 		default:
1681 			__cpu_name[cpu] = "Au1xxx";
1682 			break;
1683 		}
1684 		break;
1685 	}
1686 }
1687 
1688 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
1689 {
1690 	decode_configs(c);
1691 
1692 	c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1693 	switch (c->processor_id & PRID_IMP_MASK) {
1694 	case PRID_IMP_SB1:
1695 		c->cputype = CPU_SB1;
1696 		__cpu_name[cpu] = "SiByte SB1";
1697 		/* FPU in pass1 is known to have issues. */
1698 		if ((c->processor_id & PRID_REV_MASK) < 0x02)
1699 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
1700 		break;
1701 	case PRID_IMP_SB1A:
1702 		c->cputype = CPU_SB1A;
1703 		__cpu_name[cpu] = "SiByte SB1A";
1704 		break;
1705 	}
1706 }
1707 
1708 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
1709 {
1710 	decode_configs(c);
1711 	switch (c->processor_id & PRID_IMP_MASK) {
1712 	case PRID_IMP_SR71000:
1713 		c->cputype = CPU_SR71000;
1714 		__cpu_name[cpu] = "Sandcraft SR71000";
1715 		c->scache.ways = 8;
1716 		c->tlbsize = 64;
1717 		break;
1718 	}
1719 }
1720 
1721 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
1722 {
1723 	decode_configs(c);
1724 	switch (c->processor_id & PRID_IMP_MASK) {
1725 	case PRID_IMP_PR4450:
1726 		c->cputype = CPU_PR4450;
1727 		__cpu_name[cpu] = "Philips PR4450";
1728 		set_isa(c, MIPS_CPU_ISA_M32R1);
1729 		break;
1730 	}
1731 }
1732 
1733 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
1734 {
1735 	decode_configs(c);
1736 	switch (c->processor_id & PRID_IMP_MASK) {
1737 	case PRID_IMP_BMIPS32_REV4:
1738 	case PRID_IMP_BMIPS32_REV8:
1739 		c->cputype = CPU_BMIPS32;
1740 		__cpu_name[cpu] = "Broadcom BMIPS32";
1741 		set_elf_platform(cpu, "bmips32");
1742 		break;
1743 	case PRID_IMP_BMIPS3300:
1744 	case PRID_IMP_BMIPS3300_ALT:
1745 	case PRID_IMP_BMIPS3300_BUG:
1746 		c->cputype = CPU_BMIPS3300;
1747 		__cpu_name[cpu] = "Broadcom BMIPS3300";
1748 		set_elf_platform(cpu, "bmips3300");
1749 		break;
1750 	case PRID_IMP_BMIPS43XX: {
1751 		int rev = c->processor_id & PRID_REV_MASK;
1752 
1753 		if (rev >= PRID_REV_BMIPS4380_LO &&
1754 				rev <= PRID_REV_BMIPS4380_HI) {
1755 			c->cputype = CPU_BMIPS4380;
1756 			__cpu_name[cpu] = "Broadcom BMIPS4380";
1757 			set_elf_platform(cpu, "bmips4380");
1758 			c->options |= MIPS_CPU_RIXI;
1759 		} else {
1760 			c->cputype = CPU_BMIPS4350;
1761 			__cpu_name[cpu] = "Broadcom BMIPS4350";
1762 			set_elf_platform(cpu, "bmips4350");
1763 		}
1764 		break;
1765 	}
1766 	case PRID_IMP_BMIPS5000:
1767 	case PRID_IMP_BMIPS5200:
1768 		c->cputype = CPU_BMIPS5000;
1769 		if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_BMIPS5200)
1770 			__cpu_name[cpu] = "Broadcom BMIPS5200";
1771 		else
1772 			__cpu_name[cpu] = "Broadcom BMIPS5000";
1773 		set_elf_platform(cpu, "bmips5000");
1774 		c->options |= MIPS_CPU_ULRI | MIPS_CPU_RIXI;
1775 		break;
1776 	}
1777 }
1778 
1779 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
1780 {
1781 	decode_configs(c);
1782 	switch (c->processor_id & PRID_IMP_MASK) {
1783 	case PRID_IMP_CAVIUM_CN38XX:
1784 	case PRID_IMP_CAVIUM_CN31XX:
1785 	case PRID_IMP_CAVIUM_CN30XX:
1786 		c->cputype = CPU_CAVIUM_OCTEON;
1787 		__cpu_name[cpu] = "Cavium Octeon";
1788 		goto platform;
1789 	case PRID_IMP_CAVIUM_CN58XX:
1790 	case PRID_IMP_CAVIUM_CN56XX:
1791 	case PRID_IMP_CAVIUM_CN50XX:
1792 	case PRID_IMP_CAVIUM_CN52XX:
1793 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
1794 		__cpu_name[cpu] = "Cavium Octeon+";
1795 platform:
1796 		set_elf_platform(cpu, "octeon");
1797 		break;
1798 	case PRID_IMP_CAVIUM_CN61XX:
1799 	case PRID_IMP_CAVIUM_CN63XX:
1800 	case PRID_IMP_CAVIUM_CN66XX:
1801 	case PRID_IMP_CAVIUM_CN68XX:
1802 	case PRID_IMP_CAVIUM_CNF71XX:
1803 		c->cputype = CPU_CAVIUM_OCTEON2;
1804 		__cpu_name[cpu] = "Cavium Octeon II";
1805 		set_elf_platform(cpu, "octeon2");
1806 		break;
1807 	case PRID_IMP_CAVIUM_CN70XX:
1808 	case PRID_IMP_CAVIUM_CN73XX:
1809 	case PRID_IMP_CAVIUM_CNF75XX:
1810 	case PRID_IMP_CAVIUM_CN78XX:
1811 		c->cputype = CPU_CAVIUM_OCTEON3;
1812 		__cpu_name[cpu] = "Cavium Octeon III";
1813 		set_elf_platform(cpu, "octeon3");
1814 		break;
1815 	default:
1816 		printk(KERN_INFO "Unknown Octeon chip!\n");
1817 		c->cputype = CPU_UNKNOWN;
1818 		break;
1819 	}
1820 }
1821 
1822 static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
1823 {
1824 	switch (c->processor_id & PRID_IMP_MASK) {
1825 	case PRID_IMP_LOONGSON_64:  /* Loongson-2/3 */
1826 		switch (c->processor_id & PRID_REV_MASK) {
1827 		case PRID_REV_LOONGSON3A_R2:
1828 			c->cputype = CPU_LOONGSON3;
1829 			__cpu_name[cpu] = "ICT Loongson-3";
1830 			set_elf_platform(cpu, "loongson3a");
1831 			set_isa(c, MIPS_CPU_ISA_M64R2);
1832 			break;
1833 		}
1834 
1835 		decode_configs(c);
1836 		c->options |= MIPS_CPU_FTLB | MIPS_CPU_TLBINV | MIPS_CPU_LDPTE;
1837 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1838 		break;
1839 	default:
1840 		panic("Unknown Loongson Processor ID!");
1841 		break;
1842 	}
1843 }
1844 
1845 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
1846 {
1847 	decode_configs(c);
1848 	/* JZRISC does not implement the CP0 counter. */
1849 	c->options &= ~MIPS_CPU_COUNTER;
1850 	BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);
1851 	switch (c->processor_id & PRID_IMP_MASK) {
1852 	case PRID_IMP_JZRISC:
1853 		c->cputype = CPU_JZRISC;
1854 		c->writecombine = _CACHE_UNCACHED_ACCELERATED;
1855 		__cpu_name[cpu] = "Ingenic JZRISC";
1856 		break;
1857 	default:
1858 		panic("Unknown Ingenic Processor ID!");
1859 		break;
1860 	}
1861 }
1862 
1863 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1864 {
1865 	decode_configs(c);
1866 
1867 	if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_NETLOGIC_AU13XX) {
1868 		c->cputype = CPU_ALCHEMY;
1869 		__cpu_name[cpu] = "Au1300";
1870 		/* following stuff is not for Alchemy */
1871 		return;
1872 	}
1873 
1874 	c->options = (MIPS_CPU_TLB	 |
1875 			MIPS_CPU_4KEX	 |
1876 			MIPS_CPU_COUNTER |
1877 			MIPS_CPU_DIVEC	 |
1878 			MIPS_CPU_WATCH	 |
1879 			MIPS_CPU_EJTAG	 |
1880 			MIPS_CPU_LLSC);
1881 
1882 	switch (c->processor_id & PRID_IMP_MASK) {
1883 	case PRID_IMP_NETLOGIC_XLP2XX:
1884 	case PRID_IMP_NETLOGIC_XLP9XX:
1885 	case PRID_IMP_NETLOGIC_XLP5XX:
1886 		c->cputype = CPU_XLP;
1887 		__cpu_name[cpu] = "Broadcom XLPII";
1888 		break;
1889 
1890 	case PRID_IMP_NETLOGIC_XLP8XX:
1891 	case PRID_IMP_NETLOGIC_XLP3XX:
1892 		c->cputype = CPU_XLP;
1893 		__cpu_name[cpu] = "Netlogic XLP";
1894 		break;
1895 
1896 	case PRID_IMP_NETLOGIC_XLR732:
1897 	case PRID_IMP_NETLOGIC_XLR716:
1898 	case PRID_IMP_NETLOGIC_XLR532:
1899 	case PRID_IMP_NETLOGIC_XLR308:
1900 	case PRID_IMP_NETLOGIC_XLR532C:
1901 	case PRID_IMP_NETLOGIC_XLR516C:
1902 	case PRID_IMP_NETLOGIC_XLR508C:
1903 	case PRID_IMP_NETLOGIC_XLR308C:
1904 		c->cputype = CPU_XLR;
1905 		__cpu_name[cpu] = "Netlogic XLR";
1906 		break;
1907 
1908 	case PRID_IMP_NETLOGIC_XLS608:
1909 	case PRID_IMP_NETLOGIC_XLS408:
1910 	case PRID_IMP_NETLOGIC_XLS404:
1911 	case PRID_IMP_NETLOGIC_XLS208:
1912 	case PRID_IMP_NETLOGIC_XLS204:
1913 	case PRID_IMP_NETLOGIC_XLS108:
1914 	case PRID_IMP_NETLOGIC_XLS104:
1915 	case PRID_IMP_NETLOGIC_XLS616B:
1916 	case PRID_IMP_NETLOGIC_XLS608B:
1917 	case PRID_IMP_NETLOGIC_XLS416B:
1918 	case PRID_IMP_NETLOGIC_XLS412B:
1919 	case PRID_IMP_NETLOGIC_XLS408B:
1920 	case PRID_IMP_NETLOGIC_XLS404B:
1921 		c->cputype = CPU_XLR;
1922 		__cpu_name[cpu] = "Netlogic XLS";
1923 		break;
1924 
1925 	default:
1926 		pr_info("Unknown Netlogic chip id [%02x]!\n",
1927 		       c->processor_id);
1928 		c->cputype = CPU_XLR;
1929 		break;
1930 	}
1931 
1932 	if (c->cputype == CPU_XLP) {
1933 		set_isa(c, MIPS_CPU_ISA_M64R2);
1934 		c->options |= (MIPS_CPU_FPU | MIPS_CPU_ULRI | MIPS_CPU_MCHECK);
1935 		/* This will be updated again after all threads are woken up */
1936 		c->tlbsize = ((read_c0_config6() >> 16) & 0xffff) + 1;
1937 	} else {
1938 		set_isa(c, MIPS_CPU_ISA_M64R1);
1939 		c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
1940 	}
1941 	c->kscratch_mask = 0xf;
1942 }
1943 
1944 #ifdef CONFIG_64BIT
1945 /* For use by uaccess.h */
1946 u64 __ua_limit;
1947 EXPORT_SYMBOL(__ua_limit);
1948 #endif
1949 
1950 const char *__cpu_name[NR_CPUS];
1951 const char *__elf_platform;
1952 
1953 void cpu_probe(void)
1954 {
1955 	struct cpuinfo_mips *c = &current_cpu_data;
1956 	unsigned int cpu = smp_processor_id();
1957 
1958 	c->processor_id = PRID_IMP_UNKNOWN;
1959 	c->fpu_id	= FPIR_IMP_NONE;
1960 	c->cputype	= CPU_UNKNOWN;
1961 	c->writecombine = _CACHE_UNCACHED;
1962 
1963 	c->fpu_csr31	= FPU_CSR_RN;
1964 	c->fpu_msk31	= FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
1965 
1966 	c->processor_id = read_c0_prid();
1967 	switch (c->processor_id & PRID_COMP_MASK) {
1968 	case PRID_COMP_LEGACY:
1969 		cpu_probe_legacy(c, cpu);
1970 		break;
1971 	case PRID_COMP_MIPS:
1972 		cpu_probe_mips(c, cpu);
1973 		break;
1974 	case PRID_COMP_ALCHEMY:
1975 		cpu_probe_alchemy(c, cpu);
1976 		break;
1977 	case PRID_COMP_SIBYTE:
1978 		cpu_probe_sibyte(c, cpu);
1979 		break;
1980 	case PRID_COMP_BROADCOM:
1981 		cpu_probe_broadcom(c, cpu);
1982 		break;
1983 	case PRID_COMP_SANDCRAFT:
1984 		cpu_probe_sandcraft(c, cpu);
1985 		break;
1986 	case PRID_COMP_NXP:
1987 		cpu_probe_nxp(c, cpu);
1988 		break;
1989 	case PRID_COMP_CAVIUM:
1990 		cpu_probe_cavium(c, cpu);
1991 		break;
1992 	case PRID_COMP_LOONGSON:
1993 		cpu_probe_loongson(c, cpu);
1994 		break;
1995 	case PRID_COMP_INGENIC_D0:
1996 	case PRID_COMP_INGENIC_D1:
1997 	case PRID_COMP_INGENIC_E1:
1998 		cpu_probe_ingenic(c, cpu);
1999 		break;
2000 	case PRID_COMP_NETLOGIC:
2001 		cpu_probe_netlogic(c, cpu);
2002 		break;
2003 	}
2004 
2005 	BUG_ON(!__cpu_name[cpu]);
2006 	BUG_ON(c->cputype == CPU_UNKNOWN);
2007 
2008 	/*
2009 	 * Platform code can force the cpu type to optimize code
2010 	 * generation. In that case be sure the cpu type is correctly
2011 	 * manually setup otherwise it could trigger some nasty bugs.
2012 	 */
2013 	BUG_ON(current_cpu_type() != c->cputype);
2014 
2015 	if (cpu_has_rixi) {
2016 		/* Enable the RIXI exceptions */
2017 		set_c0_pagegrain(PG_IEC);
2018 		back_to_back_c0_hazard();
2019 		/* Verify the IEC bit is set */
2020 		if (read_c0_pagegrain() & PG_IEC)
2021 			c->options |= MIPS_CPU_RIXIEX;
2022 	}
2023 
2024 	if (mips_fpu_disabled)
2025 		c->options &= ~MIPS_CPU_FPU;
2026 
2027 	if (mips_dsp_disabled)
2028 		c->ases &= ~(MIPS_ASE_DSP | MIPS_ASE_DSP2P);
2029 
2030 	if (mips_htw_disabled) {
2031 		c->options &= ~MIPS_CPU_HTW;
2032 		write_c0_pwctl(read_c0_pwctl() &
2033 			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));
2034 	}
2035 
2036 	if (c->options & MIPS_CPU_FPU)
2037 		cpu_set_fpu_opts(c);
2038 	else
2039 		cpu_set_nofpu_opts(c);
2040 
2041 	if (cpu_has_bp_ghist)
2042 		write_c0_r10k_diag(read_c0_r10k_diag() |
2043 				   R10K_DIAG_E_GHIST);
2044 
2045 	if (cpu_has_mips_r2_r6) {
2046 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
2047 		/* R2 has Performance Counter Interrupt indicator */
2048 		c->options |= MIPS_CPU_PCI;
2049 	}
2050 	else
2051 		c->srsets = 1;
2052 
2053 	if (cpu_has_mips_r6)
2054 		elf_hwcap |= HWCAP_MIPS_R6;
2055 
2056 	if (cpu_has_msa) {
2057 		c->msa_id = cpu_get_msa_id();
2058 		WARN(c->msa_id & MSA_IR_WRPF,
2059 		     "Vector register partitioning unimplemented!");
2060 		elf_hwcap |= HWCAP_MIPS_MSA;
2061 	}
2062 
2063 	if (cpu_has_vz)
2064 		cpu_probe_vz(c);
2065 
2066 	cpu_probe_vmbits(c);
2067 
2068 #ifdef CONFIG_64BIT
2069 	if (cpu == 0)
2070 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
2071 #endif
2072 }
2073 
2074 void cpu_report(void)
2075 {
2076 	struct cpuinfo_mips *c = &current_cpu_data;
2077 
2078 	pr_info("CPU%d revision is: %08x (%s)\n",
2079 		smp_processor_id(), c->processor_id, cpu_name_string());
2080 	if (c->options & MIPS_CPU_FPU)
2081 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
2082 	if (cpu_has_msa)
2083 		pr_info("MSA revision is: %08x\n", c->msa_id);
2084 }
2085