xref: /linux/arch/mips/kernel/cpu-probe.c (revision 3eeebf17f31c583f83e081b17b3076477cb96886)
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  MIPS 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/stddef.h>
18 
19 #include <asm/bugs.h>
20 #include <asm/cpu.h>
21 #include <asm/fpu.h>
22 #include <asm/mipsregs.h>
23 #include <asm/system.h>
24 #include <asm/watch.h>
25 
26 /*
27  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
28  * the implementation of the "wait" feature differs between CPU families. This
29  * points to the function that implements CPU specific wait.
30  * The wait instruction stops the pipeline and reduces the power consumption of
31  * the CPU very much.
32  */
33 void (*cpu_wait)(void) = NULL;
34 
35 static void r3081_wait(void)
36 {
37 	unsigned long cfg = read_c0_conf();
38 	write_c0_conf(cfg | R30XX_CONF_HALT);
39 }
40 
41 static void r39xx_wait(void)
42 {
43 	local_irq_disable();
44 	if (!need_resched())
45 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
46 	local_irq_enable();
47 }
48 
49 extern void r4k_wait(void);
50 
51 /*
52  * This variant is preferable as it allows testing need_resched and going to
53  * sleep depending on the outcome atomically.  Unfortunately the "It is
54  * implementation-dependent whether the pipeline restarts when a non-enabled
55  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
56  * using this version a gamble.
57  */
58 void r4k_wait_irqoff(void)
59 {
60 	local_irq_disable();
61 	if (!need_resched())
62 		__asm__("	.set	push		\n"
63 			"	.set	mips3		\n"
64 			"	wait			\n"
65 			"	.set	pop		\n");
66 	local_irq_enable();
67 	__asm__(" 	.globl __pastwait	\n"
68 		"__pastwait:			\n");
69 	return;
70 }
71 
72 /*
73  * The RM7000 variant has to handle erratum 38.  The workaround is to not
74  * have any pending stores when the WAIT instruction is executed.
75  */
76 static void rm7k_wait_irqoff(void)
77 {
78 	local_irq_disable();
79 	if (!need_resched())
80 		__asm__(
81 		"	.set	push					\n"
82 		"	.set	mips3					\n"
83 		"	.set	noat					\n"
84 		"	mfc0	$1, $12					\n"
85 		"	sync						\n"
86 		"	mtc0	$1, $12		# stalls until W stage	\n"
87 		"	wait						\n"
88 		"	mtc0	$1, $12		# stalls until W stage	\n"
89 		"	.set	pop					\n");
90 	local_irq_enable();
91 }
92 
93 /* The Au1xxx wait is available only if using 32khz counter or
94  * external timer source, but specifically not CP0 Counter. */
95 int allow_au1k_wait;
96 
97 static void au1k_wait(void)
98 {
99 	/* using the wait instruction makes CP0 counter unusable */
100 	__asm__("	.set	mips3			\n"
101 		"	cache	0x14, 0(%0)		\n"
102 		"	cache	0x14, 32(%0)		\n"
103 		"	sync				\n"
104 		"	nop				\n"
105 		"	wait				\n"
106 		"	nop				\n"
107 		"	nop				\n"
108 		"	nop				\n"
109 		"	nop				\n"
110 		"	.set	mips0			\n"
111 		: : "r" (au1k_wait));
112 }
113 
114 static int __initdata nowait = 0;
115 
116 static int __init wait_disable(char *s)
117 {
118 	nowait = 1;
119 
120 	return 1;
121 }
122 
123 __setup("nowait", wait_disable);
124 
125 void __init check_wait(void)
126 {
127 	struct cpuinfo_mips *c = &current_cpu_data;
128 
129 	if (nowait) {
130 		printk("Wait instruction disabled.\n");
131 		return;
132 	}
133 
134 	switch (c->cputype) {
135 	case CPU_R3081:
136 	case CPU_R3081E:
137 		cpu_wait = r3081_wait;
138 		break;
139 	case CPU_TX3927:
140 		cpu_wait = r39xx_wait;
141 		break;
142 	case CPU_R4200:
143 /*	case CPU_R4300: */
144 	case CPU_R4600:
145 	case CPU_R4640:
146 	case CPU_R4650:
147 	case CPU_R4700:
148 	case CPU_R5000:
149 	case CPU_NEVADA:
150 	case CPU_4KC:
151 	case CPU_4KEC:
152 	case CPU_4KSC:
153 	case CPU_5KC:
154 	case CPU_25KF:
155 	case CPU_PR4450:
156 	case CPU_BCM3302:
157 		cpu_wait = r4k_wait;
158 		break;
159 
160 	case CPU_RM7000:
161 		cpu_wait = rm7k_wait_irqoff;
162 		break;
163 
164 	case CPU_24K:
165 	case CPU_34K:
166 	case CPU_1004K:
167 		cpu_wait = r4k_wait;
168 		if (read_c0_config7() & MIPS_CONF7_WII)
169 			cpu_wait = r4k_wait_irqoff;
170 		break;
171 
172 	case CPU_74K:
173 		cpu_wait = r4k_wait;
174 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
175 			cpu_wait = r4k_wait_irqoff;
176 		break;
177 
178 	case CPU_TX49XX:
179 		cpu_wait = r4k_wait_irqoff;
180 		break;
181 	case CPU_AU1000:
182 	case CPU_AU1100:
183 	case CPU_AU1500:
184 	case CPU_AU1550:
185 	case CPU_AU1200:
186 	case CPU_AU1210:
187 	case CPU_AU1250:
188 		if (allow_au1k_wait)
189 			cpu_wait = au1k_wait;
190 		break;
191 	case CPU_20KC:
192 		/*
193 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
194 		 * WAIT on Rev2.0 and Rev3.0 has E16.
195 		 * Rev3.1 WAIT is nop, why bother
196 		 */
197 		if ((c->processor_id & 0xff) <= 0x64)
198 			break;
199 
200 		/*
201 		 * Another rev is incremeting c0_count at a reduced clock
202 		 * rate while in WAIT mode.  So we basically have the choice
203 		 * between using the cp0 timer as clocksource or avoiding
204 		 * the WAIT instruction.  Until more details are known,
205 		 * disable the use of WAIT for 20Kc entirely.
206 		   cpu_wait = r4k_wait;
207 		 */
208 		break;
209 	case CPU_RM9000:
210 		if ((c->processor_id & 0x00ff) >= 0x40)
211 			cpu_wait = r4k_wait;
212 		break;
213 	default:
214 		break;
215 	}
216 }
217 
218 static inline void check_errata(void)
219 {
220 	struct cpuinfo_mips *c = &current_cpu_data;
221 
222 	switch (c->cputype) {
223 	case CPU_34K:
224 		/*
225 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
226 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
227 		 * making use of VPE1 will be responsable for that VPE.
228 		 */
229 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
230 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
231 		break;
232 	default:
233 		break;
234 	}
235 }
236 
237 void __init check_bugs32(void)
238 {
239 	check_errata();
240 }
241 
242 /*
243  * Probe whether cpu has config register by trying to play with
244  * alternate cache bit and see whether it matters.
245  * It's used by cpu_probe to distinguish between R3000A and R3081.
246  */
247 static inline int cpu_has_confreg(void)
248 {
249 #ifdef CONFIG_CPU_R3000
250 	extern unsigned long r3k_cache_size(unsigned long);
251 	unsigned long size1, size2;
252 	unsigned long cfg = read_c0_conf();
253 
254 	size1 = r3k_cache_size(ST0_ISC);
255 	write_c0_conf(cfg ^ R30XX_CONF_AC);
256 	size2 = r3k_cache_size(ST0_ISC);
257 	write_c0_conf(cfg);
258 	return size1 != size2;
259 #else
260 	return 0;
261 #endif
262 }
263 
264 /*
265  * Get the FPU Implementation/Revision.
266  */
267 static inline unsigned long cpu_get_fpu_id(void)
268 {
269 	unsigned long tmp, fpu_id;
270 
271 	tmp = read_c0_status();
272 	__enable_fpu();
273 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
274 	write_c0_status(tmp);
275 	return fpu_id;
276 }
277 
278 /*
279  * Check the CPU has an FPU the official way.
280  */
281 static inline int __cpu_has_fpu(void)
282 {
283 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
284 }
285 
286 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
287 		| MIPS_CPU_COUNTER)
288 
289 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
290 {
291 	switch (c->processor_id & 0xff00) {
292 	case PRID_IMP_R2000:
293 		c->cputype = CPU_R2000;
294 		c->isa_level = MIPS_CPU_ISA_I;
295 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
296 		             MIPS_CPU_NOFPUEX;
297 		if (__cpu_has_fpu())
298 			c->options |= MIPS_CPU_FPU;
299 		c->tlbsize = 64;
300 		break;
301 	case PRID_IMP_R3000:
302 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
303 			if (cpu_has_confreg())
304 				c->cputype = CPU_R3081E;
305 			else
306 				c->cputype = CPU_R3000A;
307 		else
308 			c->cputype = CPU_R3000;
309 		c->isa_level = MIPS_CPU_ISA_I;
310 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
311 		             MIPS_CPU_NOFPUEX;
312 		if (__cpu_has_fpu())
313 			c->options |= MIPS_CPU_FPU;
314 		c->tlbsize = 64;
315 		break;
316 	case PRID_IMP_R4000:
317 		if (read_c0_config() & CONF_SC) {
318 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
319 				c->cputype = CPU_R4400PC;
320 			else
321 				c->cputype = CPU_R4000PC;
322 		} else {
323 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
324 				c->cputype = CPU_R4400SC;
325 			else
326 				c->cputype = CPU_R4000SC;
327 		}
328 
329 		c->isa_level = MIPS_CPU_ISA_III;
330 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
331 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
332 		             MIPS_CPU_LLSC;
333 		c->tlbsize = 48;
334 		break;
335 	case PRID_IMP_VR41XX:
336 		switch (c->processor_id & 0xf0) {
337 		case PRID_REV_VR4111:
338 			c->cputype = CPU_VR4111;
339 			break;
340 		case PRID_REV_VR4121:
341 			c->cputype = CPU_VR4121;
342 			break;
343 		case PRID_REV_VR4122:
344 			if ((c->processor_id & 0xf) < 0x3)
345 				c->cputype = CPU_VR4122;
346 			else
347 				c->cputype = CPU_VR4181A;
348 			break;
349 		case PRID_REV_VR4130:
350 			if ((c->processor_id & 0xf) < 0x4)
351 				c->cputype = CPU_VR4131;
352 			else
353 				c->cputype = CPU_VR4133;
354 			break;
355 		default:
356 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
357 			c->cputype = CPU_VR41XX;
358 			break;
359 		}
360 		c->isa_level = MIPS_CPU_ISA_III;
361 		c->options = R4K_OPTS;
362 		c->tlbsize = 32;
363 		break;
364 	case PRID_IMP_R4300:
365 		c->cputype = CPU_R4300;
366 		c->isa_level = MIPS_CPU_ISA_III;
367 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
368 		             MIPS_CPU_LLSC;
369 		c->tlbsize = 32;
370 		break;
371 	case PRID_IMP_R4600:
372 		c->cputype = CPU_R4600;
373 		c->isa_level = MIPS_CPU_ISA_III;
374 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
375 			     MIPS_CPU_LLSC;
376 		c->tlbsize = 48;
377 		break;
378 	#if 0
379  	case PRID_IMP_R4650:
380 		/*
381 		 * This processor doesn't have an MMU, so it's not
382 		 * "real easy" to run Linux on it. It is left purely
383 		 * for documentation.  Commented out because it shares
384 		 * it's c0_prid id number with the TX3900.
385 		 */
386 		c->cputype = CPU_R4650;
387 	 	c->isa_level = MIPS_CPU_ISA_III;
388 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
389 	        c->tlbsize = 48;
390 		break;
391 	#endif
392 	case PRID_IMP_TX39:
393 		c->isa_level = MIPS_CPU_ISA_I;
394 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
395 
396 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
397 			c->cputype = CPU_TX3927;
398 			c->tlbsize = 64;
399 		} else {
400 			switch (c->processor_id & 0xff) {
401 			case PRID_REV_TX3912:
402 				c->cputype = CPU_TX3912;
403 				c->tlbsize = 32;
404 				break;
405 			case PRID_REV_TX3922:
406 				c->cputype = CPU_TX3922;
407 				c->tlbsize = 64;
408 				break;
409 			default:
410 				c->cputype = CPU_UNKNOWN;
411 				break;
412 			}
413 		}
414 		break;
415 	case PRID_IMP_R4700:
416 		c->cputype = CPU_R4700;
417 		c->isa_level = MIPS_CPU_ISA_III;
418 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
419 		             MIPS_CPU_LLSC;
420 		c->tlbsize = 48;
421 		break;
422 	case PRID_IMP_TX49:
423 		c->cputype = CPU_TX49XX;
424 		c->isa_level = MIPS_CPU_ISA_III;
425 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
426 		if (!(c->processor_id & 0x08))
427 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
428 		c->tlbsize = 48;
429 		break;
430 	case PRID_IMP_R5000:
431 		c->cputype = CPU_R5000;
432 		c->isa_level = MIPS_CPU_ISA_IV;
433 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
434 		             MIPS_CPU_LLSC;
435 		c->tlbsize = 48;
436 		break;
437 	case PRID_IMP_R5432:
438 		c->cputype = CPU_R5432;
439 		c->isa_level = MIPS_CPU_ISA_IV;
440 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
441 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
442 		c->tlbsize = 48;
443 		break;
444 	case PRID_IMP_R5500:
445 		c->cputype = CPU_R5500;
446 		c->isa_level = MIPS_CPU_ISA_IV;
447 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
448 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
449 		c->tlbsize = 48;
450 		break;
451 	case PRID_IMP_NEVADA:
452 		c->cputype = CPU_NEVADA;
453 		c->isa_level = MIPS_CPU_ISA_IV;
454 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
455 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
456 		c->tlbsize = 48;
457 		break;
458 	case PRID_IMP_R6000:
459 		c->cputype = CPU_R6000;
460 		c->isa_level = MIPS_CPU_ISA_II;
461 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
462 		             MIPS_CPU_LLSC;
463 		c->tlbsize = 32;
464 		break;
465 	case PRID_IMP_R6000A:
466 		c->cputype = CPU_R6000A;
467 		c->isa_level = MIPS_CPU_ISA_II;
468 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
469 		             MIPS_CPU_LLSC;
470 		c->tlbsize = 32;
471 		break;
472 	case PRID_IMP_RM7000:
473 		c->cputype = CPU_RM7000;
474 		c->isa_level = MIPS_CPU_ISA_IV;
475 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
476 		             MIPS_CPU_LLSC;
477 		/*
478 		 * Undocumented RM7000:  Bit 29 in the info register of
479 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
480 		 * entries.
481 		 *
482 		 * 29      1 =>    64 entry JTLB
483 		 *         0 =>    48 entry JTLB
484 		 */
485 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
486 		break;
487 	case PRID_IMP_RM9000:
488 		c->cputype = CPU_RM9000;
489 		c->isa_level = MIPS_CPU_ISA_IV;
490 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
491 		             MIPS_CPU_LLSC;
492 		/*
493 		 * Bit 29 in the info register of the RM9000
494 		 * indicates if the TLB has 48 or 64 entries.
495 		 *
496 		 * 29      1 =>    64 entry JTLB
497 		 *         0 =>    48 entry JTLB
498 		 */
499 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
500 		break;
501 	case PRID_IMP_R8000:
502 		c->cputype = CPU_R8000;
503 		c->isa_level = MIPS_CPU_ISA_IV;
504 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
505 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
506 		             MIPS_CPU_LLSC;
507 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
508 		break;
509 	case PRID_IMP_R10000:
510 		c->cputype = CPU_R10000;
511 		c->isa_level = MIPS_CPU_ISA_IV;
512 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
513 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
514 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
515 		             MIPS_CPU_LLSC;
516 		c->tlbsize = 64;
517 		break;
518 	case PRID_IMP_R12000:
519 		c->cputype = CPU_R12000;
520 		c->isa_level = MIPS_CPU_ISA_IV;
521 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
522 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
523 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
524 		             MIPS_CPU_LLSC;
525 		c->tlbsize = 64;
526 		break;
527 	case PRID_IMP_R14000:
528 		c->cputype = CPU_R14000;
529 		c->isa_level = MIPS_CPU_ISA_IV;
530 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
531 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
532 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
533 		             MIPS_CPU_LLSC;
534 		c->tlbsize = 64;
535 		break;
536 	case PRID_IMP_LOONGSON2:
537 		c->cputype = CPU_LOONGSON2;
538 		c->isa_level = MIPS_CPU_ISA_III;
539 		c->options = R4K_OPTS |
540 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
541 			     MIPS_CPU_32FPR;
542 		c->tlbsize = 64;
543 		break;
544 	}
545 }
546 
547 static char unknown_isa[] __cpuinitdata = KERN_ERR \
548 	"Unsupported ISA type, c0.config0: %d.";
549 
550 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
551 {
552 	unsigned int config0;
553 	int isa;
554 
555 	config0 = read_c0_config();
556 
557 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
558 		c->options |= MIPS_CPU_TLB;
559 	isa = (config0 & MIPS_CONF_AT) >> 13;
560 	switch (isa) {
561 	case 0:
562 		switch ((config0 & MIPS_CONF_AR) >> 10) {
563 		case 0:
564 			c->isa_level = MIPS_CPU_ISA_M32R1;
565 			break;
566 		case 1:
567 			c->isa_level = MIPS_CPU_ISA_M32R2;
568 			break;
569 		default:
570 			goto unknown;
571 		}
572 		break;
573 	case 2:
574 		switch ((config0 & MIPS_CONF_AR) >> 10) {
575 		case 0:
576 			c->isa_level = MIPS_CPU_ISA_M64R1;
577 			break;
578 		case 1:
579 			c->isa_level = MIPS_CPU_ISA_M64R2;
580 			break;
581 		default:
582 			goto unknown;
583 		}
584 		break;
585 	default:
586 		goto unknown;
587 	}
588 
589 	return config0 & MIPS_CONF_M;
590 
591 unknown:
592 	panic(unknown_isa, config0);
593 }
594 
595 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
596 {
597 	unsigned int config1;
598 
599 	config1 = read_c0_config1();
600 
601 	if (config1 & MIPS_CONF1_MD)
602 		c->ases |= MIPS_ASE_MDMX;
603 	if (config1 & MIPS_CONF1_WR)
604 		c->options |= MIPS_CPU_WATCH;
605 	if (config1 & MIPS_CONF1_CA)
606 		c->ases |= MIPS_ASE_MIPS16;
607 	if (config1 & MIPS_CONF1_EP)
608 		c->options |= MIPS_CPU_EJTAG;
609 	if (config1 & MIPS_CONF1_FP) {
610 		c->options |= MIPS_CPU_FPU;
611 		c->options |= MIPS_CPU_32FPR;
612 	}
613 	if (cpu_has_tlb)
614 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
615 
616 	return config1 & MIPS_CONF_M;
617 }
618 
619 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
620 {
621 	unsigned int config2;
622 
623 	config2 = read_c0_config2();
624 
625 	if (config2 & MIPS_CONF2_SL)
626 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
627 
628 	return config2 & MIPS_CONF_M;
629 }
630 
631 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
632 {
633 	unsigned int config3;
634 
635 	config3 = read_c0_config3();
636 
637 	if (config3 & MIPS_CONF3_SM)
638 		c->ases |= MIPS_ASE_SMARTMIPS;
639 	if (config3 & MIPS_CONF3_DSP)
640 		c->ases |= MIPS_ASE_DSP;
641 	if (config3 & MIPS_CONF3_VINT)
642 		c->options |= MIPS_CPU_VINT;
643 	if (config3 & MIPS_CONF3_VEIC)
644 		c->options |= MIPS_CPU_VEIC;
645 	if (config3 & MIPS_CONF3_MT)
646 	        c->ases |= MIPS_ASE_MIPSMT;
647 	if (config3 & MIPS_CONF3_ULRI)
648 		c->options |= MIPS_CPU_ULRI;
649 
650 	return config3 & MIPS_CONF_M;
651 }
652 
653 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
654 {
655 	/* MIPS32 or MIPS64 compliant CPU.  */
656 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
657 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
658 
659 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
660 
661 	/* Read Config registers.  */
662 	if (!decode_config0(c))
663 		return;			/* actually worth a panic() */
664 	if (!decode_config1(c))
665 		return;
666 	if (!decode_config2(c))
667 		return;
668 	if (!decode_config3(c))
669 		return;
670 }
671 
672 #ifdef CONFIG_CPU_MIPSR2
673 extern void spram_config(void);
674 #else
675 static inline void spram_config(void) {}
676 #endif
677 
678 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
679 {
680 	decode_configs(c);
681 	mips_probe_watch_registers(c);
682 	switch (c->processor_id & 0xff00) {
683 	case PRID_IMP_4KC:
684 		c->cputype = CPU_4KC;
685 		break;
686 	case PRID_IMP_4KEC:
687 		c->cputype = CPU_4KEC;
688 		break;
689 	case PRID_IMP_4KECR2:
690 		c->cputype = CPU_4KEC;
691 		break;
692 	case PRID_IMP_4KSC:
693 	case PRID_IMP_4KSD:
694 		c->cputype = CPU_4KSC;
695 		break;
696 	case PRID_IMP_5KC:
697 		c->cputype = CPU_5KC;
698 		break;
699 	case PRID_IMP_20KC:
700 		c->cputype = CPU_20KC;
701 		break;
702 	case PRID_IMP_24K:
703 	case PRID_IMP_24KE:
704 		c->cputype = CPU_24K;
705 		break;
706 	case PRID_IMP_25KF:
707 		c->cputype = CPU_25KF;
708 		break;
709 	case PRID_IMP_34K:
710 		c->cputype = CPU_34K;
711 		break;
712 	case PRID_IMP_74K:
713 		c->cputype = CPU_74K;
714 		break;
715 	case PRID_IMP_1004K:
716 		c->cputype = CPU_1004K;
717 		break;
718 	}
719 
720 	spram_config();
721 }
722 
723 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
724 {
725 	decode_configs(c);
726 	switch (c->processor_id & 0xff00) {
727 	case PRID_IMP_AU1_REV1:
728 	case PRID_IMP_AU1_REV2:
729 		switch ((c->processor_id >> 24) & 0xff) {
730 		case 0:
731 			c->cputype = CPU_AU1000;
732 			break;
733 		case 1:
734 			c->cputype = CPU_AU1500;
735 			break;
736 		case 2:
737 			c->cputype = CPU_AU1100;
738 			break;
739 		case 3:
740 			c->cputype = CPU_AU1550;
741 			break;
742 		case 4:
743 			c->cputype = CPU_AU1200;
744 			if (2 == (c->processor_id & 0xff))
745 				c->cputype = CPU_AU1250;
746 			break;
747 		case 5:
748 			c->cputype = CPU_AU1210;
749 			break;
750 		default:
751 			panic("Unknown Au Core!");
752 			break;
753 		}
754 		break;
755 	}
756 }
757 
758 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
759 {
760 	decode_configs(c);
761 
762 	switch (c->processor_id & 0xff00) {
763 	case PRID_IMP_SB1:
764 		c->cputype = CPU_SB1;
765 		/* FPU in pass1 is known to have issues. */
766 		if ((c->processor_id & 0xff) < 0x02)
767 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
768 		break;
769 	case PRID_IMP_SB1A:
770 		c->cputype = CPU_SB1A;
771 		break;
772 	}
773 }
774 
775 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
776 {
777 	decode_configs(c);
778 	switch (c->processor_id & 0xff00) {
779 	case PRID_IMP_SR71000:
780 		c->cputype = CPU_SR71000;
781 		c->scache.ways = 8;
782 		c->tlbsize = 64;
783 		break;
784 	}
785 }
786 
787 static inline void cpu_probe_nxp(struct cpuinfo_mips *c)
788 {
789 	decode_configs(c);
790 	switch (c->processor_id & 0xff00) {
791 	case PRID_IMP_PR4450:
792 		c->cputype = CPU_PR4450;
793 		c->isa_level = MIPS_CPU_ISA_M32R1;
794 		break;
795 	default:
796 		panic("Unknown NXP Core!"); /* REVISIT: die? */
797 		break;
798 	}
799 }
800 
801 
802 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c)
803 {
804 	decode_configs(c);
805 	switch (c->processor_id & 0xff00) {
806 	case PRID_IMP_BCM3302:
807 		c->cputype = CPU_BCM3302;
808 		break;
809 	case PRID_IMP_BCM4710:
810 		c->cputype = CPU_BCM4710;
811 		break;
812 	default:
813 		c->cputype = CPU_UNKNOWN;
814 		break;
815 	}
816 }
817 
818 const char *__cpu_name[NR_CPUS];
819 
820 /*
821  * Name a CPU
822  */
823 static __cpuinit const char *cpu_to_name(struct cpuinfo_mips *c)
824 {
825 	const char *name = NULL;
826 
827 	switch (c->cputype) {
828 	case CPU_UNKNOWN:	name = "unknown"; break;
829 	case CPU_R2000:		name = "R2000"; break;
830 	case CPU_R3000:		name = "R3000"; break;
831 	case CPU_R3000A:	name = "R3000A"; break;
832 	case CPU_R3041:		name = "R3041"; break;
833 	case CPU_R3051:		name = "R3051"; break;
834 	case CPU_R3052:		name = "R3052"; break;
835 	case CPU_R3081:		name = "R3081"; break;
836 	case CPU_R3081E:	name = "R3081E"; break;
837 	case CPU_R4000PC:	name = "R4000PC"; break;
838 	case CPU_R4000SC:	name = "R4000SC"; break;
839 	case CPU_R4000MC:	name = "R4000MC"; break;
840 	case CPU_R4200:		name = "R4200"; break;
841 	case CPU_R4400PC:	name = "R4400PC"; break;
842 	case CPU_R4400SC:	name = "R4400SC"; break;
843 	case CPU_R4400MC:	name = "R4400MC"; break;
844 	case CPU_R4600:		name = "R4600"; break;
845 	case CPU_R6000:		name = "R6000"; break;
846 	case CPU_R6000A:	name = "R6000A"; break;
847 	case CPU_R8000:		name = "R8000"; break;
848 	case CPU_R10000:	name = "R10000"; break;
849 	case CPU_R12000:	name = "R12000"; break;
850 	case CPU_R14000:	name = "R14000"; break;
851 	case CPU_R4300:		name = "R4300"; break;
852 	case CPU_R4650:		name = "R4650"; break;
853 	case CPU_R4700:		name = "R4700"; break;
854 	case CPU_R5000:		name = "R5000"; break;
855 	case CPU_R5000A:	name = "R5000A"; break;
856 	case CPU_R4640:		name = "R4640"; break;
857 	case CPU_NEVADA:	name = "Nevada"; break;
858 	case CPU_RM7000:	name = "RM7000"; break;
859 	case CPU_RM9000:	name = "RM9000"; break;
860 	case CPU_R5432:		name = "R5432"; break;
861 	case CPU_4KC:		name = "MIPS 4Kc"; break;
862 	case CPU_5KC:		name = "MIPS 5Kc"; break;
863 	case CPU_R4310:		name = "R4310"; break;
864 	case CPU_SB1:		name = "SiByte SB1"; break;
865 	case CPU_SB1A:		name = "SiByte SB1A"; break;
866 	case CPU_TX3912:	name = "TX3912"; break;
867 	case CPU_TX3922:	name = "TX3922"; break;
868 	case CPU_TX3927:	name = "TX3927"; break;
869 	case CPU_AU1000:	name = "Au1000"; break;
870 	case CPU_AU1500:	name = "Au1500"; break;
871 	case CPU_AU1100:	name = "Au1100"; break;
872 	case CPU_AU1550:	name = "Au1550"; break;
873 	case CPU_AU1200:	name = "Au1200"; break;
874 	case CPU_AU1210:	name = "Au1210"; break;
875 	case CPU_AU1250:	name = "Au1250"; break;
876 	case CPU_4KEC:		name = "MIPS 4KEc"; break;
877 	case CPU_4KSC:		name = "MIPS 4KSc"; break;
878 	case CPU_VR41XX:	name = "NEC Vr41xx"; break;
879 	case CPU_R5500:		name = "R5500"; break;
880 	case CPU_TX49XX:	name = "TX49xx"; break;
881 	case CPU_20KC:		name = "MIPS 20Kc"; break;
882 	case CPU_24K:		name = "MIPS 24K"; break;
883 	case CPU_25KF:		name = "MIPS 25Kf"; break;
884 	case CPU_34K:		name = "MIPS 34K"; break;
885 	case CPU_1004K:		name = "MIPS 1004K"; break;
886 	case CPU_74K:		name = "MIPS 74K"; break;
887 	case CPU_VR4111:	name = "NEC VR4111"; break;
888 	case CPU_VR4121:	name = "NEC VR4121"; break;
889 	case CPU_VR4122:	name = "NEC VR4122"; break;
890 	case CPU_VR4131:	name = "NEC VR4131"; break;
891 	case CPU_VR4133:	name = "NEC VR4133"; break;
892 	case CPU_VR4181:	name = "NEC VR4181"; break;
893 	case CPU_VR4181A:	name = "NEC VR4181A"; break;
894 	case CPU_SR71000:	name = "Sandcraft SR71000"; break;
895 	case CPU_BCM3302:	name = "Broadcom BCM3302"; break;
896 	case CPU_BCM4710:	name = "Broadcom BCM4710"; break;
897 	case CPU_PR4450:	name = "Philips PR4450"; break;
898 	case CPU_LOONGSON2:	name = "ICT Loongson-2"; break;
899 	default:
900 		BUG();
901 	}
902 
903 	return name;
904 }
905 
906 __cpuinit void cpu_probe(void)
907 {
908 	struct cpuinfo_mips *c = &current_cpu_data;
909 	unsigned int cpu = smp_processor_id();
910 
911 	c->processor_id	= PRID_IMP_UNKNOWN;
912 	c->fpu_id	= FPIR_IMP_NONE;
913 	c->cputype	= CPU_UNKNOWN;
914 
915 	c->processor_id = read_c0_prid();
916 	switch (c->processor_id & 0xff0000) {
917 	case PRID_COMP_LEGACY:
918 		cpu_probe_legacy(c);
919 		break;
920 	case PRID_COMP_MIPS:
921 		cpu_probe_mips(c);
922 		break;
923 	case PRID_COMP_ALCHEMY:
924 		cpu_probe_alchemy(c);
925 		break;
926 	case PRID_COMP_SIBYTE:
927 		cpu_probe_sibyte(c);
928 		break;
929 	case PRID_COMP_BROADCOM:
930 		cpu_probe_broadcom(c);
931 		break;
932 	case PRID_COMP_SANDCRAFT:
933 		cpu_probe_sandcraft(c);
934 		break;
935 	case PRID_COMP_NXP:
936 		cpu_probe_nxp(c);
937 		break;
938 	default:
939 		c->cputype = CPU_UNKNOWN;
940 	}
941 
942 	/*
943 	 * Platform code can force the cpu type to optimize code
944 	 * generation. In that case be sure the cpu type is correctly
945 	 * manually setup otherwise it could trigger some nasty bugs.
946 	 */
947 	BUG_ON(current_cpu_type() != c->cputype);
948 
949 	if (c->options & MIPS_CPU_FPU) {
950 		c->fpu_id = cpu_get_fpu_id();
951 
952 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
953 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
954 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
955 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
956 			if (c->fpu_id & MIPS_FPIR_3D)
957 				c->ases |= MIPS_ASE_MIPS3D;
958 		}
959 	}
960 
961 	__cpu_name[cpu] = cpu_to_name(c);
962 
963 	if (cpu_has_mips_r2)
964 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
965 	else
966 		c->srsets = 1;
967 }
968 
969 __cpuinit void cpu_report(void)
970 {
971 	struct cpuinfo_mips *c = &current_cpu_data;
972 
973 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
974 	       c->processor_id, cpu_name_string());
975 	if (c->options & MIPS_CPU_FPU)
976 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
977 }
978