xref: /linux/arch/mips/kernel/cpu-probe.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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 	if (!allow_au1k_wait)
100 		return;
101 
102 	/* using the wait instruction makes CP0 counter unusable */
103 	__asm__("	.set	mips3			\n"
104 		"	cache	0x14, 0(%0)		\n"
105 		"	cache	0x14, 32(%0)		\n"
106 		"	sync				\n"
107 		"	nop				\n"
108 		"	wait				\n"
109 		"	nop				\n"
110 		"	nop				\n"
111 		"	nop				\n"
112 		"	nop				\n"
113 		"	.set	mips0			\n"
114 		: : "r" (au1k_wait));
115 }
116 
117 static int __initdata nowait = 0;
118 
119 static int __init wait_disable(char *s)
120 {
121 	nowait = 1;
122 
123 	return 1;
124 }
125 
126 __setup("nowait", wait_disable);
127 
128 void __init check_wait(void)
129 {
130 	struct cpuinfo_mips *c = &current_cpu_data;
131 
132 	if (nowait) {
133 		printk("Wait instruction disabled.\n");
134 		return;
135 	}
136 
137 	switch (c->cputype) {
138 	case CPU_R3081:
139 	case CPU_R3081E:
140 		cpu_wait = r3081_wait;
141 		break;
142 	case CPU_TX3927:
143 		cpu_wait = r39xx_wait;
144 		break;
145 	case CPU_R4200:
146 /*	case CPU_R4300: */
147 	case CPU_R4600:
148 	case CPU_R4640:
149 	case CPU_R4650:
150 	case CPU_R4700:
151 	case CPU_R5000:
152 	case CPU_NEVADA:
153 	case CPU_4KC:
154 	case CPU_4KEC:
155 	case CPU_4KSC:
156 	case CPU_5KC:
157 	case CPU_25KF:
158 	case CPU_PR4450:
159 	case CPU_BCM3302:
160 	case CPU_CAVIUM_OCTEON:
161 		cpu_wait = r4k_wait;
162 		break;
163 
164 	case CPU_RM7000:
165 		cpu_wait = rm7k_wait_irqoff;
166 		break;
167 
168 	case CPU_24K:
169 	case CPU_34K:
170 	case CPU_1004K:
171 		cpu_wait = r4k_wait;
172 		if (read_c0_config7() & MIPS_CONF7_WII)
173 			cpu_wait = r4k_wait_irqoff;
174 		break;
175 
176 	case CPU_74K:
177 		cpu_wait = r4k_wait;
178 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
179 			cpu_wait = r4k_wait_irqoff;
180 		break;
181 
182 	case CPU_TX49XX:
183 		cpu_wait = r4k_wait_irqoff;
184 		break;
185 	case CPU_AU1000:
186 	case CPU_AU1100:
187 	case CPU_AU1500:
188 	case CPU_AU1550:
189 	case CPU_AU1200:
190 	case CPU_AU1210:
191 	case CPU_AU1250:
192 		cpu_wait = au1k_wait;
193 		break;
194 	case CPU_20KC:
195 		/*
196 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
197 		 * WAIT on Rev2.0 and Rev3.0 has E16.
198 		 * Rev3.1 WAIT is nop, why bother
199 		 */
200 		if ((c->processor_id & 0xff) <= 0x64)
201 			break;
202 
203 		/*
204 		 * Another rev is incremeting c0_count at a reduced clock
205 		 * rate while in WAIT mode.  So we basically have the choice
206 		 * between using the cp0 timer as clocksource or avoiding
207 		 * the WAIT instruction.  Until more details are known,
208 		 * disable the use of WAIT for 20Kc entirely.
209 		   cpu_wait = r4k_wait;
210 		 */
211 		break;
212 	case CPU_RM9000:
213 		if ((c->processor_id & 0x00ff) >= 0x40)
214 			cpu_wait = r4k_wait;
215 		break;
216 	default:
217 		break;
218 	}
219 }
220 
221 static inline void check_errata(void)
222 {
223 	struct cpuinfo_mips *c = &current_cpu_data;
224 
225 	switch (c->cputype) {
226 	case CPU_34K:
227 		/*
228 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
229 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
230 		 * making use of VPE1 will be responsable for that VPE.
231 		 */
232 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
233 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
234 		break;
235 	default:
236 		break;
237 	}
238 }
239 
240 void __init check_bugs32(void)
241 {
242 	check_errata();
243 }
244 
245 /*
246  * Probe whether cpu has config register by trying to play with
247  * alternate cache bit and see whether it matters.
248  * It's used by cpu_probe to distinguish between R3000A and R3081.
249  */
250 static inline int cpu_has_confreg(void)
251 {
252 #ifdef CONFIG_CPU_R3000
253 	extern unsigned long r3k_cache_size(unsigned long);
254 	unsigned long size1, size2;
255 	unsigned long cfg = read_c0_conf();
256 
257 	size1 = r3k_cache_size(ST0_ISC);
258 	write_c0_conf(cfg ^ R30XX_CONF_AC);
259 	size2 = r3k_cache_size(ST0_ISC);
260 	write_c0_conf(cfg);
261 	return size1 != size2;
262 #else
263 	return 0;
264 #endif
265 }
266 
267 /*
268  * Get the FPU Implementation/Revision.
269  */
270 static inline unsigned long cpu_get_fpu_id(void)
271 {
272 	unsigned long tmp, fpu_id;
273 
274 	tmp = read_c0_status();
275 	__enable_fpu();
276 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
277 	write_c0_status(tmp);
278 	return fpu_id;
279 }
280 
281 /*
282  * Check the CPU has an FPU the official way.
283  */
284 static inline int __cpu_has_fpu(void)
285 {
286 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
287 }
288 
289 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
290 		| MIPS_CPU_COUNTER)
291 
292 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
293 {
294 	switch (c->processor_id & 0xff00) {
295 	case PRID_IMP_R2000:
296 		c->cputype = CPU_R2000;
297 		__cpu_name[cpu] = "R2000";
298 		c->isa_level = MIPS_CPU_ISA_I;
299 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
300 		             MIPS_CPU_NOFPUEX;
301 		if (__cpu_has_fpu())
302 			c->options |= MIPS_CPU_FPU;
303 		c->tlbsize = 64;
304 		break;
305 	case PRID_IMP_R3000:
306 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
307 			if (cpu_has_confreg()) {
308 				c->cputype = CPU_R3081E;
309 				__cpu_name[cpu] = "R3081";
310 			} else {
311 				c->cputype = CPU_R3000A;
312 				__cpu_name[cpu] = "R3000A";
313 			}
314 			break;
315 		} else {
316 			c->cputype = CPU_R3000;
317 			__cpu_name[cpu] = "R3000";
318 		}
319 		c->isa_level = MIPS_CPU_ISA_I;
320 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
321 		             MIPS_CPU_NOFPUEX;
322 		if (__cpu_has_fpu())
323 			c->options |= MIPS_CPU_FPU;
324 		c->tlbsize = 64;
325 		break;
326 	case PRID_IMP_R4000:
327 		if (read_c0_config() & CONF_SC) {
328 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
329 				c->cputype = CPU_R4400PC;
330 				__cpu_name[cpu] = "R4400PC";
331 			} else {
332 				c->cputype = CPU_R4000PC;
333 				__cpu_name[cpu] = "R4000PC";
334 			}
335 		} else {
336 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
337 				c->cputype = CPU_R4400SC;
338 				__cpu_name[cpu] = "R4400SC";
339 			} else {
340 				c->cputype = CPU_R4000SC;
341 				__cpu_name[cpu] = "R4000SC";
342 			}
343 		}
344 
345 		c->isa_level = MIPS_CPU_ISA_III;
346 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
347 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
348 		             MIPS_CPU_LLSC;
349 		c->tlbsize = 48;
350 		break;
351 	case PRID_IMP_VR41XX:
352 		switch (c->processor_id & 0xf0) {
353 		case PRID_REV_VR4111:
354 			c->cputype = CPU_VR4111;
355 			__cpu_name[cpu] = "NEC VR4111";
356 			break;
357 		case PRID_REV_VR4121:
358 			c->cputype = CPU_VR4121;
359 			__cpu_name[cpu] = "NEC VR4121";
360 			break;
361 		case PRID_REV_VR4122:
362 			if ((c->processor_id & 0xf) < 0x3) {
363 				c->cputype = CPU_VR4122;
364 				__cpu_name[cpu] = "NEC VR4122";
365 			} else {
366 				c->cputype = CPU_VR4181A;
367 				__cpu_name[cpu] = "NEC VR4181A";
368 			}
369 			break;
370 		case PRID_REV_VR4130:
371 			if ((c->processor_id & 0xf) < 0x4) {
372 				c->cputype = CPU_VR4131;
373 				__cpu_name[cpu] = "NEC VR4131";
374 			} else {
375 				c->cputype = CPU_VR4133;
376 				__cpu_name[cpu] = "NEC VR4133";
377 			}
378 			break;
379 		default:
380 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
381 			c->cputype = CPU_VR41XX;
382 			__cpu_name[cpu] = "NEC Vr41xx";
383 			break;
384 		}
385 		c->isa_level = MIPS_CPU_ISA_III;
386 		c->options = R4K_OPTS;
387 		c->tlbsize = 32;
388 		break;
389 	case PRID_IMP_R4300:
390 		c->cputype = CPU_R4300;
391 		__cpu_name[cpu] = "R4300";
392 		c->isa_level = MIPS_CPU_ISA_III;
393 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
394 		             MIPS_CPU_LLSC;
395 		c->tlbsize = 32;
396 		break;
397 	case PRID_IMP_R4600:
398 		c->cputype = CPU_R4600;
399 		__cpu_name[cpu] = "R4600";
400 		c->isa_level = MIPS_CPU_ISA_III;
401 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
402 			     MIPS_CPU_LLSC;
403 		c->tlbsize = 48;
404 		break;
405 	#if 0
406  	case PRID_IMP_R4650:
407 		/*
408 		 * This processor doesn't have an MMU, so it's not
409 		 * "real easy" to run Linux on it. It is left purely
410 		 * for documentation.  Commented out because it shares
411 		 * it's c0_prid id number with the TX3900.
412 		 */
413 		c->cputype = CPU_R4650;
414 		__cpu_name[cpu] = "R4650";
415 	 	c->isa_level = MIPS_CPU_ISA_III;
416 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
417 	        c->tlbsize = 48;
418 		break;
419 	#endif
420 	case PRID_IMP_TX39:
421 		c->isa_level = MIPS_CPU_ISA_I;
422 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
423 
424 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
425 			c->cputype = CPU_TX3927;
426 			__cpu_name[cpu] = "TX3927";
427 			c->tlbsize = 64;
428 		} else {
429 			switch (c->processor_id & 0xff) {
430 			case PRID_REV_TX3912:
431 				c->cputype = CPU_TX3912;
432 				__cpu_name[cpu] = "TX3912";
433 				c->tlbsize = 32;
434 				break;
435 			case PRID_REV_TX3922:
436 				c->cputype = CPU_TX3922;
437 				__cpu_name[cpu] = "TX3922";
438 				c->tlbsize = 64;
439 				break;
440 			}
441 		}
442 		break;
443 	case PRID_IMP_R4700:
444 		c->cputype = CPU_R4700;
445 		__cpu_name[cpu] = "R4700";
446 		c->isa_level = MIPS_CPU_ISA_III;
447 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
448 		             MIPS_CPU_LLSC;
449 		c->tlbsize = 48;
450 		break;
451 	case PRID_IMP_TX49:
452 		c->cputype = CPU_TX49XX;
453 		__cpu_name[cpu] = "R49XX";
454 		c->isa_level = MIPS_CPU_ISA_III;
455 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
456 		if (!(c->processor_id & 0x08))
457 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
458 		c->tlbsize = 48;
459 		break;
460 	case PRID_IMP_R5000:
461 		c->cputype = CPU_R5000;
462 		__cpu_name[cpu] = "R5000";
463 		c->isa_level = MIPS_CPU_ISA_IV;
464 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
465 		             MIPS_CPU_LLSC;
466 		c->tlbsize = 48;
467 		break;
468 	case PRID_IMP_R5432:
469 		c->cputype = CPU_R5432;
470 		__cpu_name[cpu] = "R5432";
471 		c->isa_level = MIPS_CPU_ISA_IV;
472 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
473 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
474 		c->tlbsize = 48;
475 		break;
476 	case PRID_IMP_R5500:
477 		c->cputype = CPU_R5500;
478 		__cpu_name[cpu] = "R5500";
479 		c->isa_level = MIPS_CPU_ISA_IV;
480 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
481 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
482 		c->tlbsize = 48;
483 		break;
484 	case PRID_IMP_NEVADA:
485 		c->cputype = CPU_NEVADA;
486 		__cpu_name[cpu] = "Nevada";
487 		c->isa_level = MIPS_CPU_ISA_IV;
488 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
489 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
490 		c->tlbsize = 48;
491 		break;
492 	case PRID_IMP_R6000:
493 		c->cputype = CPU_R6000;
494 		__cpu_name[cpu] = "R6000";
495 		c->isa_level = MIPS_CPU_ISA_II;
496 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
497 		             MIPS_CPU_LLSC;
498 		c->tlbsize = 32;
499 		break;
500 	case PRID_IMP_R6000A:
501 		c->cputype = CPU_R6000A;
502 		__cpu_name[cpu] = "R6000A";
503 		c->isa_level = MIPS_CPU_ISA_II;
504 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
505 		             MIPS_CPU_LLSC;
506 		c->tlbsize = 32;
507 		break;
508 	case PRID_IMP_RM7000:
509 		c->cputype = CPU_RM7000;
510 		__cpu_name[cpu] = "RM7000";
511 		c->isa_level = MIPS_CPU_ISA_IV;
512 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
513 		             MIPS_CPU_LLSC;
514 		/*
515 		 * Undocumented RM7000:  Bit 29 in the info register of
516 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
517 		 * entries.
518 		 *
519 		 * 29      1 =>    64 entry JTLB
520 		 *         0 =>    48 entry JTLB
521 		 */
522 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
523 		break;
524 	case PRID_IMP_RM9000:
525 		c->cputype = CPU_RM9000;
526 		__cpu_name[cpu] = "RM9000";
527 		c->isa_level = MIPS_CPU_ISA_IV;
528 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
529 		             MIPS_CPU_LLSC;
530 		/*
531 		 * Bit 29 in the info register of the RM9000
532 		 * indicates if the TLB has 48 or 64 entries.
533 		 *
534 		 * 29      1 =>    64 entry JTLB
535 		 *         0 =>    48 entry JTLB
536 		 */
537 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
538 		break;
539 	case PRID_IMP_R8000:
540 		c->cputype = CPU_R8000;
541 		__cpu_name[cpu] = "RM8000";
542 		c->isa_level = MIPS_CPU_ISA_IV;
543 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
544 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
545 		             MIPS_CPU_LLSC;
546 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
547 		break;
548 	case PRID_IMP_R10000:
549 		c->cputype = CPU_R10000;
550 		__cpu_name[cpu] = "R10000";
551 		c->isa_level = MIPS_CPU_ISA_IV;
552 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
553 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
554 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
555 		             MIPS_CPU_LLSC;
556 		c->tlbsize = 64;
557 		break;
558 	case PRID_IMP_R12000:
559 		c->cputype = CPU_R12000;
560 		__cpu_name[cpu] = "R12000";
561 		c->isa_level = MIPS_CPU_ISA_IV;
562 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
563 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
564 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
565 		             MIPS_CPU_LLSC;
566 		c->tlbsize = 64;
567 		break;
568 	case PRID_IMP_R14000:
569 		c->cputype = CPU_R14000;
570 		__cpu_name[cpu] = "R14000";
571 		c->isa_level = MIPS_CPU_ISA_IV;
572 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
573 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
574 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
575 		             MIPS_CPU_LLSC;
576 		c->tlbsize = 64;
577 		break;
578 	case PRID_IMP_LOONGSON2:
579 		c->cputype = CPU_LOONGSON2;
580 		__cpu_name[cpu] = "ICT Loongson-2";
581 		c->isa_level = MIPS_CPU_ISA_III;
582 		c->options = R4K_OPTS |
583 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
584 			     MIPS_CPU_32FPR;
585 		c->tlbsize = 64;
586 		break;
587 	}
588 }
589 
590 static char unknown_isa[] __cpuinitdata = KERN_ERR \
591 	"Unsupported ISA type, c0.config0: %d.";
592 
593 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
594 {
595 	unsigned int config0;
596 	int isa;
597 
598 	config0 = read_c0_config();
599 
600 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
601 		c->options |= MIPS_CPU_TLB;
602 	isa = (config0 & MIPS_CONF_AT) >> 13;
603 	switch (isa) {
604 	case 0:
605 		switch ((config0 & MIPS_CONF_AR) >> 10) {
606 		case 0:
607 			c->isa_level = MIPS_CPU_ISA_M32R1;
608 			break;
609 		case 1:
610 			c->isa_level = MIPS_CPU_ISA_M32R2;
611 			break;
612 		default:
613 			goto unknown;
614 		}
615 		break;
616 	case 2:
617 		switch ((config0 & MIPS_CONF_AR) >> 10) {
618 		case 0:
619 			c->isa_level = MIPS_CPU_ISA_M64R1;
620 			break;
621 		case 1:
622 			c->isa_level = MIPS_CPU_ISA_M64R2;
623 			break;
624 		default:
625 			goto unknown;
626 		}
627 		break;
628 	default:
629 		goto unknown;
630 	}
631 
632 	return config0 & MIPS_CONF_M;
633 
634 unknown:
635 	panic(unknown_isa, config0);
636 }
637 
638 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
639 {
640 	unsigned int config1;
641 
642 	config1 = read_c0_config1();
643 
644 	if (config1 & MIPS_CONF1_MD)
645 		c->ases |= MIPS_ASE_MDMX;
646 	if (config1 & MIPS_CONF1_WR)
647 		c->options |= MIPS_CPU_WATCH;
648 	if (config1 & MIPS_CONF1_CA)
649 		c->ases |= MIPS_ASE_MIPS16;
650 	if (config1 & MIPS_CONF1_EP)
651 		c->options |= MIPS_CPU_EJTAG;
652 	if (config1 & MIPS_CONF1_FP) {
653 		c->options |= MIPS_CPU_FPU;
654 		c->options |= MIPS_CPU_32FPR;
655 	}
656 	if (cpu_has_tlb)
657 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
658 
659 	return config1 & MIPS_CONF_M;
660 }
661 
662 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
663 {
664 	unsigned int config2;
665 
666 	config2 = read_c0_config2();
667 
668 	if (config2 & MIPS_CONF2_SL)
669 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
670 
671 	return config2 & MIPS_CONF_M;
672 }
673 
674 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
675 {
676 	unsigned int config3;
677 
678 	config3 = read_c0_config3();
679 
680 	if (config3 & MIPS_CONF3_SM)
681 		c->ases |= MIPS_ASE_SMARTMIPS;
682 	if (config3 & MIPS_CONF3_DSP)
683 		c->ases |= MIPS_ASE_DSP;
684 	if (config3 & MIPS_CONF3_VINT)
685 		c->options |= MIPS_CPU_VINT;
686 	if (config3 & MIPS_CONF3_VEIC)
687 		c->options |= MIPS_CPU_VEIC;
688 	if (config3 & MIPS_CONF3_MT)
689 	        c->ases |= MIPS_ASE_MIPSMT;
690 	if (config3 & MIPS_CONF3_ULRI)
691 		c->options |= MIPS_CPU_ULRI;
692 
693 	return config3 & MIPS_CONF_M;
694 }
695 
696 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
697 {
698 	int ok;
699 
700 	/* MIPS32 or MIPS64 compliant CPU.  */
701 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
702 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
703 
704 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
705 
706 	ok = decode_config0(c);			/* Read Config registers.  */
707 	BUG_ON(!ok);				/* Arch spec violation!  */
708 	if (ok)
709 		ok = decode_config1(c);
710 	if (ok)
711 		ok = decode_config2(c);
712 	if (ok)
713 		ok = decode_config3(c);
714 
715 	mips_probe_watch_registers(c);
716 }
717 
718 #ifdef CONFIG_CPU_MIPSR2
719 extern void spram_config(void);
720 #else
721 static inline void spram_config(void) {}
722 #endif
723 
724 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
725 {
726 	decode_configs(c);
727 	switch (c->processor_id & 0xff00) {
728 	case PRID_IMP_4KC:
729 		c->cputype = CPU_4KC;
730 		__cpu_name[cpu] = "MIPS 4Kc";
731 		break;
732 	case PRID_IMP_4KEC:
733 		c->cputype = CPU_4KEC;
734 		__cpu_name[cpu] = "MIPS 4KEc";
735 		break;
736 	case PRID_IMP_4KECR2:
737 		c->cputype = CPU_4KEC;
738 		__cpu_name[cpu] = "MIPS 4KEc";
739 		break;
740 	case PRID_IMP_4KSC:
741 	case PRID_IMP_4KSD:
742 		c->cputype = CPU_4KSC;
743 		__cpu_name[cpu] = "MIPS 4KSc";
744 		break;
745 	case PRID_IMP_5KC:
746 		c->cputype = CPU_5KC;
747 		__cpu_name[cpu] = "MIPS 5Kc";
748 		break;
749 	case PRID_IMP_20KC:
750 		c->cputype = CPU_20KC;
751 		__cpu_name[cpu] = "MIPS 20Kc";
752 		break;
753 	case PRID_IMP_24K:
754 	case PRID_IMP_24KE:
755 		c->cputype = CPU_24K;
756 		__cpu_name[cpu] = "MIPS 24Kc";
757 		break;
758 	case PRID_IMP_25KF:
759 		c->cputype = CPU_25KF;
760 		__cpu_name[cpu] = "MIPS 25Kc";
761 		break;
762 	case PRID_IMP_34K:
763 		c->cputype = CPU_34K;
764 		__cpu_name[cpu] = "MIPS 34Kc";
765 		break;
766 	case PRID_IMP_74K:
767 		c->cputype = CPU_74K;
768 		__cpu_name[cpu] = "MIPS 74Kc";
769 		break;
770 	case PRID_IMP_1004K:
771 		c->cputype = CPU_1004K;
772 		__cpu_name[cpu] = "MIPS 1004Kc";
773 		break;
774 	}
775 
776 	spram_config();
777 }
778 
779 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
780 {
781 	decode_configs(c);
782 	switch (c->processor_id & 0xff00) {
783 	case PRID_IMP_AU1_REV1:
784 	case PRID_IMP_AU1_REV2:
785 		switch ((c->processor_id >> 24) & 0xff) {
786 		case 0:
787 			c->cputype = CPU_AU1000;
788 			__cpu_name[cpu] = "Au1000";
789 			break;
790 		case 1:
791 			c->cputype = CPU_AU1500;
792 			__cpu_name[cpu] = "Au1500";
793 			break;
794 		case 2:
795 			c->cputype = CPU_AU1100;
796 			__cpu_name[cpu] = "Au1100";
797 			break;
798 		case 3:
799 			c->cputype = CPU_AU1550;
800 			__cpu_name[cpu] = "Au1550";
801 			break;
802 		case 4:
803 			c->cputype = CPU_AU1200;
804 			__cpu_name[cpu] = "Au1200";
805 			if ((c->processor_id & 0xff) == 2) {
806 				c->cputype = CPU_AU1250;
807 				__cpu_name[cpu] = "Au1250";
808 			}
809 			break;
810 		case 5:
811 			c->cputype = CPU_AU1210;
812 			__cpu_name[cpu] = "Au1210";
813 			break;
814 		default:
815 			panic("Unknown Au Core!");
816 			break;
817 		}
818 		break;
819 	}
820 }
821 
822 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
823 {
824 	decode_configs(c);
825 
826 	switch (c->processor_id & 0xff00) {
827 	case PRID_IMP_SB1:
828 		c->cputype = CPU_SB1;
829 		__cpu_name[cpu] = "SiByte SB1";
830 		/* FPU in pass1 is known to have issues. */
831 		if ((c->processor_id & 0xff) < 0x02)
832 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
833 		break;
834 	case PRID_IMP_SB1A:
835 		c->cputype = CPU_SB1A;
836 		__cpu_name[cpu] = "SiByte SB1A";
837 		break;
838 	}
839 }
840 
841 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
842 {
843 	decode_configs(c);
844 	switch (c->processor_id & 0xff00) {
845 	case PRID_IMP_SR71000:
846 		c->cputype = CPU_SR71000;
847 		__cpu_name[cpu] = "Sandcraft SR71000";
848 		c->scache.ways = 8;
849 		c->tlbsize = 64;
850 		break;
851 	}
852 }
853 
854 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
855 {
856 	decode_configs(c);
857 	switch (c->processor_id & 0xff00) {
858 	case PRID_IMP_PR4450:
859 		c->cputype = CPU_PR4450;
860 		__cpu_name[cpu] = "Philips PR4450";
861 		c->isa_level = MIPS_CPU_ISA_M32R1;
862 		break;
863 	}
864 }
865 
866 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
867 {
868 	decode_configs(c);
869 	switch (c->processor_id & 0xff00) {
870 	case PRID_IMP_BCM3302:
871 		c->cputype = CPU_BCM3302;
872 		__cpu_name[cpu] = "Broadcom BCM3302";
873 		break;
874 	case PRID_IMP_BCM4710:
875 		c->cputype = CPU_BCM4710;
876 		__cpu_name[cpu] = "Broadcom BCM4710";
877 		break;
878 	}
879 }
880 
881 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
882 {
883 	decode_configs(c);
884 	switch (c->processor_id & 0xff00) {
885 	case PRID_IMP_CAVIUM_CN38XX:
886 	case PRID_IMP_CAVIUM_CN31XX:
887 	case PRID_IMP_CAVIUM_CN30XX:
888 	case PRID_IMP_CAVIUM_CN58XX:
889 	case PRID_IMP_CAVIUM_CN56XX:
890 	case PRID_IMP_CAVIUM_CN50XX:
891 	case PRID_IMP_CAVIUM_CN52XX:
892 		c->cputype = CPU_CAVIUM_OCTEON;
893 		__cpu_name[cpu] = "Cavium Octeon";
894 		break;
895 	default:
896 		printk(KERN_INFO "Unknown Octeon chip!\n");
897 		c->cputype = CPU_UNKNOWN;
898 		break;
899 	}
900 }
901 
902 const char *__cpu_name[NR_CPUS];
903 
904 __cpuinit void cpu_probe(void)
905 {
906 	struct cpuinfo_mips *c = &current_cpu_data;
907 	unsigned int cpu = smp_processor_id();
908 
909 	c->processor_id	= PRID_IMP_UNKNOWN;
910 	c->fpu_id	= FPIR_IMP_NONE;
911 	c->cputype	= CPU_UNKNOWN;
912 
913 	c->processor_id = read_c0_prid();
914 	switch (c->processor_id & 0xff0000) {
915 	case PRID_COMP_LEGACY:
916 		cpu_probe_legacy(c, cpu);
917 		break;
918 	case PRID_COMP_MIPS:
919 		cpu_probe_mips(c, cpu);
920 		break;
921 	case PRID_COMP_ALCHEMY:
922 		cpu_probe_alchemy(c, cpu);
923 		break;
924 	case PRID_COMP_SIBYTE:
925 		cpu_probe_sibyte(c, cpu);
926 		break;
927 	case PRID_COMP_BROADCOM:
928 		cpu_probe_broadcom(c, cpu);
929 		break;
930 	case PRID_COMP_SANDCRAFT:
931 		cpu_probe_sandcraft(c, cpu);
932 		break;
933 	case PRID_COMP_NXP:
934 		cpu_probe_nxp(c, cpu);
935 		break;
936 	case PRID_COMP_CAVIUM:
937 		cpu_probe_cavium(c, cpu);
938 		break;
939 	}
940 
941 	BUG_ON(!__cpu_name[cpu]);
942 	BUG_ON(c->cputype == CPU_UNKNOWN);
943 
944 	/*
945 	 * Platform code can force the cpu type to optimize code
946 	 * generation. In that case be sure the cpu type is correctly
947 	 * manually setup otherwise it could trigger some nasty bugs.
948 	 */
949 	BUG_ON(current_cpu_type() != c->cputype);
950 
951 	if (c->options & MIPS_CPU_FPU) {
952 		c->fpu_id = cpu_get_fpu_id();
953 
954 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
955 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
956 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
957 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
958 			if (c->fpu_id & MIPS_FPIR_3D)
959 				c->ases |= MIPS_ASE_MIPS3D;
960 		}
961 	}
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