xref: /linux/arch/mips/kernel/cpu-probe.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
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, unsigned int cpu)
290 {
291 	switch (c->processor_id & 0xff00) {
292 	case PRID_IMP_R2000:
293 		c->cputype = CPU_R2000;
294 		__cpu_name[cpu] = "R2000";
295 		c->isa_level = MIPS_CPU_ISA_I;
296 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
297 		             MIPS_CPU_NOFPUEX;
298 		if (__cpu_has_fpu())
299 			c->options |= MIPS_CPU_FPU;
300 		c->tlbsize = 64;
301 		break;
302 	case PRID_IMP_R3000:
303 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
304 			if (cpu_has_confreg()) {
305 				c->cputype = CPU_R3081E;
306 				__cpu_name[cpu] = "R3081";
307 			} else {
308 				c->cputype = CPU_R3000A;
309 				__cpu_name[cpu] = "R3000A";
310 			}
311 			break;
312 		} else {
313 			c->cputype = CPU_R3000;
314 			__cpu_name[cpu] = "R3000";
315 		}
316 		c->isa_level = MIPS_CPU_ISA_I;
317 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
318 		             MIPS_CPU_NOFPUEX;
319 		if (__cpu_has_fpu())
320 			c->options |= MIPS_CPU_FPU;
321 		c->tlbsize = 64;
322 		break;
323 	case PRID_IMP_R4000:
324 		if (read_c0_config() & CONF_SC) {
325 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
326 				c->cputype = CPU_R4400PC;
327 				__cpu_name[cpu] = "R4400PC";
328 			} else {
329 				c->cputype = CPU_R4000PC;
330 				__cpu_name[cpu] = "R4000PC";
331 			}
332 		} else {
333 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
334 				c->cputype = CPU_R4400SC;
335 				__cpu_name[cpu] = "R4400SC";
336 			} else {
337 				c->cputype = CPU_R4000SC;
338 				__cpu_name[cpu] = "R4000SC";
339 			}
340 		}
341 
342 		c->isa_level = MIPS_CPU_ISA_III;
343 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
344 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
345 		             MIPS_CPU_LLSC;
346 		c->tlbsize = 48;
347 		break;
348 	case PRID_IMP_VR41XX:
349 		switch (c->processor_id & 0xf0) {
350 		case PRID_REV_VR4111:
351 			c->cputype = CPU_VR4111;
352 			__cpu_name[cpu] = "NEC VR4111";
353 			break;
354 		case PRID_REV_VR4121:
355 			c->cputype = CPU_VR4121;
356 			__cpu_name[cpu] = "NEC VR4121";
357 			break;
358 		case PRID_REV_VR4122:
359 			if ((c->processor_id & 0xf) < 0x3) {
360 				c->cputype = CPU_VR4122;
361 				__cpu_name[cpu] = "NEC VR4122";
362 			} else {
363 				c->cputype = CPU_VR4181A;
364 				__cpu_name[cpu] = "NEC VR4181A";
365 			}
366 			break;
367 		case PRID_REV_VR4130:
368 			if ((c->processor_id & 0xf) < 0x4) {
369 				c->cputype = CPU_VR4131;
370 				__cpu_name[cpu] = "NEC VR4131";
371 			} else {
372 				c->cputype = CPU_VR4133;
373 				__cpu_name[cpu] = "NEC VR4133";
374 			}
375 			break;
376 		default:
377 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
378 			c->cputype = CPU_VR41XX;
379 			__cpu_name[cpu] = "NEC Vr41xx";
380 			break;
381 		}
382 		c->isa_level = MIPS_CPU_ISA_III;
383 		c->options = R4K_OPTS;
384 		c->tlbsize = 32;
385 		break;
386 	case PRID_IMP_R4300:
387 		c->cputype = CPU_R4300;
388 		__cpu_name[cpu] = "R4300";
389 		c->isa_level = MIPS_CPU_ISA_III;
390 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
391 		             MIPS_CPU_LLSC;
392 		c->tlbsize = 32;
393 		break;
394 	case PRID_IMP_R4600:
395 		c->cputype = CPU_R4600;
396 		__cpu_name[cpu] = "R4600";
397 		c->isa_level = MIPS_CPU_ISA_III;
398 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
399 			     MIPS_CPU_LLSC;
400 		c->tlbsize = 48;
401 		break;
402 	#if 0
403  	case PRID_IMP_R4650:
404 		/*
405 		 * This processor doesn't have an MMU, so it's not
406 		 * "real easy" to run Linux on it. It is left purely
407 		 * for documentation.  Commented out because it shares
408 		 * it's c0_prid id number with the TX3900.
409 		 */
410 		c->cputype = CPU_R4650;
411 		__cpu_name[cpu] = "R4650";
412 	 	c->isa_level = MIPS_CPU_ISA_III;
413 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
414 	        c->tlbsize = 48;
415 		break;
416 	#endif
417 	case PRID_IMP_TX39:
418 		c->isa_level = MIPS_CPU_ISA_I;
419 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
420 
421 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
422 			c->cputype = CPU_TX3927;
423 			__cpu_name[cpu] = "TX3927";
424 			c->tlbsize = 64;
425 		} else {
426 			switch (c->processor_id & 0xff) {
427 			case PRID_REV_TX3912:
428 				c->cputype = CPU_TX3912;
429 				__cpu_name[cpu] = "TX3912";
430 				c->tlbsize = 32;
431 				break;
432 			case PRID_REV_TX3922:
433 				c->cputype = CPU_TX3922;
434 				__cpu_name[cpu] = "TX3922";
435 				c->tlbsize = 64;
436 				break;
437 			}
438 		}
439 		break;
440 	case PRID_IMP_R4700:
441 		c->cputype = CPU_R4700;
442 		__cpu_name[cpu] = "R4700";
443 		c->isa_level = MIPS_CPU_ISA_III;
444 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
445 		             MIPS_CPU_LLSC;
446 		c->tlbsize = 48;
447 		break;
448 	case PRID_IMP_TX49:
449 		c->cputype = CPU_TX49XX;
450 		__cpu_name[cpu] = "R49XX";
451 		c->isa_level = MIPS_CPU_ISA_III;
452 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
453 		if (!(c->processor_id & 0x08))
454 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
455 		c->tlbsize = 48;
456 		break;
457 	case PRID_IMP_R5000:
458 		c->cputype = CPU_R5000;
459 		__cpu_name[cpu] = "R5000";
460 		c->isa_level = MIPS_CPU_ISA_IV;
461 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
462 		             MIPS_CPU_LLSC;
463 		c->tlbsize = 48;
464 		break;
465 	case PRID_IMP_R5432:
466 		c->cputype = CPU_R5432;
467 		__cpu_name[cpu] = "R5432";
468 		c->isa_level = MIPS_CPU_ISA_IV;
469 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
470 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
471 		c->tlbsize = 48;
472 		break;
473 	case PRID_IMP_R5500:
474 		c->cputype = CPU_R5500;
475 		__cpu_name[cpu] = "R5500";
476 		c->isa_level = MIPS_CPU_ISA_IV;
477 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
478 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
479 		c->tlbsize = 48;
480 		break;
481 	case PRID_IMP_NEVADA:
482 		c->cputype = CPU_NEVADA;
483 		__cpu_name[cpu] = "Nevada";
484 		c->isa_level = MIPS_CPU_ISA_IV;
485 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
486 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
487 		c->tlbsize = 48;
488 		break;
489 	case PRID_IMP_R6000:
490 		c->cputype = CPU_R6000;
491 		__cpu_name[cpu] = "R6000";
492 		c->isa_level = MIPS_CPU_ISA_II;
493 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
494 		             MIPS_CPU_LLSC;
495 		c->tlbsize = 32;
496 		break;
497 	case PRID_IMP_R6000A:
498 		c->cputype = CPU_R6000A;
499 		__cpu_name[cpu] = "R6000A";
500 		c->isa_level = MIPS_CPU_ISA_II;
501 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
502 		             MIPS_CPU_LLSC;
503 		c->tlbsize = 32;
504 		break;
505 	case PRID_IMP_RM7000:
506 		c->cputype = CPU_RM7000;
507 		__cpu_name[cpu] = "RM7000";
508 		c->isa_level = MIPS_CPU_ISA_IV;
509 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
510 		             MIPS_CPU_LLSC;
511 		/*
512 		 * Undocumented RM7000:  Bit 29 in the info register of
513 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
514 		 * entries.
515 		 *
516 		 * 29      1 =>    64 entry JTLB
517 		 *         0 =>    48 entry JTLB
518 		 */
519 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
520 		break;
521 	case PRID_IMP_RM9000:
522 		c->cputype = CPU_RM9000;
523 		__cpu_name[cpu] = "RM9000";
524 		c->isa_level = MIPS_CPU_ISA_IV;
525 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
526 		             MIPS_CPU_LLSC;
527 		/*
528 		 * Bit 29 in the info register of the RM9000
529 		 * indicates if the TLB has 48 or 64 entries.
530 		 *
531 		 * 29      1 =>    64 entry JTLB
532 		 *         0 =>    48 entry JTLB
533 		 */
534 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
535 		break;
536 	case PRID_IMP_R8000:
537 		c->cputype = CPU_R8000;
538 		__cpu_name[cpu] = "RM8000";
539 		c->isa_level = MIPS_CPU_ISA_IV;
540 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
541 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
542 		             MIPS_CPU_LLSC;
543 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
544 		break;
545 	case PRID_IMP_R10000:
546 		c->cputype = CPU_R10000;
547 		__cpu_name[cpu] = "R10000";
548 		c->isa_level = MIPS_CPU_ISA_IV;
549 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
550 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
551 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
552 		             MIPS_CPU_LLSC;
553 		c->tlbsize = 64;
554 		break;
555 	case PRID_IMP_R12000:
556 		c->cputype = CPU_R12000;
557 		__cpu_name[cpu] = "R12000";
558 		c->isa_level = MIPS_CPU_ISA_IV;
559 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
560 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
561 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
562 		             MIPS_CPU_LLSC;
563 		c->tlbsize = 64;
564 		break;
565 	case PRID_IMP_R14000:
566 		c->cputype = CPU_R14000;
567 		__cpu_name[cpu] = "R14000";
568 		c->isa_level = MIPS_CPU_ISA_IV;
569 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
570 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
571 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
572 		             MIPS_CPU_LLSC;
573 		c->tlbsize = 64;
574 		break;
575 	case PRID_IMP_LOONGSON2:
576 		c->cputype = CPU_LOONGSON2;
577 		__cpu_name[cpu] = "ICT Loongson-2";
578 		c->isa_level = MIPS_CPU_ISA_III;
579 		c->options = R4K_OPTS |
580 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
581 			     MIPS_CPU_32FPR;
582 		c->tlbsize = 64;
583 		break;
584 	}
585 }
586 
587 static char unknown_isa[] __cpuinitdata = KERN_ERR \
588 	"Unsupported ISA type, c0.config0: %d.";
589 
590 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
591 {
592 	unsigned int config0;
593 	int isa;
594 
595 	config0 = read_c0_config();
596 
597 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
598 		c->options |= MIPS_CPU_TLB;
599 	isa = (config0 & MIPS_CONF_AT) >> 13;
600 	switch (isa) {
601 	case 0:
602 		switch ((config0 & MIPS_CONF_AR) >> 10) {
603 		case 0:
604 			c->isa_level = MIPS_CPU_ISA_M32R1;
605 			break;
606 		case 1:
607 			c->isa_level = MIPS_CPU_ISA_M32R2;
608 			break;
609 		default:
610 			goto unknown;
611 		}
612 		break;
613 	case 2:
614 		switch ((config0 & MIPS_CONF_AR) >> 10) {
615 		case 0:
616 			c->isa_level = MIPS_CPU_ISA_M64R1;
617 			break;
618 		case 1:
619 			c->isa_level = MIPS_CPU_ISA_M64R2;
620 			break;
621 		default:
622 			goto unknown;
623 		}
624 		break;
625 	default:
626 		goto unknown;
627 	}
628 
629 	return config0 & MIPS_CONF_M;
630 
631 unknown:
632 	panic(unknown_isa, config0);
633 }
634 
635 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
636 {
637 	unsigned int config1;
638 
639 	config1 = read_c0_config1();
640 
641 	if (config1 & MIPS_CONF1_MD)
642 		c->ases |= MIPS_ASE_MDMX;
643 	if (config1 & MIPS_CONF1_WR)
644 		c->options |= MIPS_CPU_WATCH;
645 	if (config1 & MIPS_CONF1_CA)
646 		c->ases |= MIPS_ASE_MIPS16;
647 	if (config1 & MIPS_CONF1_EP)
648 		c->options |= MIPS_CPU_EJTAG;
649 	if (config1 & MIPS_CONF1_FP) {
650 		c->options |= MIPS_CPU_FPU;
651 		c->options |= MIPS_CPU_32FPR;
652 	}
653 	if (cpu_has_tlb)
654 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
655 
656 	return config1 & MIPS_CONF_M;
657 }
658 
659 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
660 {
661 	unsigned int config2;
662 
663 	config2 = read_c0_config2();
664 
665 	if (config2 & MIPS_CONF2_SL)
666 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
667 
668 	return config2 & MIPS_CONF_M;
669 }
670 
671 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
672 {
673 	unsigned int config3;
674 
675 	config3 = read_c0_config3();
676 
677 	if (config3 & MIPS_CONF3_SM)
678 		c->ases |= MIPS_ASE_SMARTMIPS;
679 	if (config3 & MIPS_CONF3_DSP)
680 		c->ases |= MIPS_ASE_DSP;
681 	if (config3 & MIPS_CONF3_VINT)
682 		c->options |= MIPS_CPU_VINT;
683 	if (config3 & MIPS_CONF3_VEIC)
684 		c->options |= MIPS_CPU_VEIC;
685 	if (config3 & MIPS_CONF3_MT)
686 	        c->ases |= MIPS_ASE_MIPSMT;
687 	if (config3 & MIPS_CONF3_ULRI)
688 		c->options |= MIPS_CPU_ULRI;
689 
690 	return config3 & MIPS_CONF_M;
691 }
692 
693 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
694 {
695 	int ok;
696 
697 	/* MIPS32 or MIPS64 compliant CPU.  */
698 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
699 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
700 
701 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
702 
703 	ok = decode_config0(c);			/* Read Config registers.  */
704 	BUG_ON(!ok);				/* Arch spec violation!  */
705 	if (ok)
706 		ok = decode_config1(c);
707 	if (ok)
708 		ok = decode_config2(c);
709 	if (ok)
710 		ok = decode_config3(c);
711 
712 	mips_probe_watch_registers(c);
713 }
714 
715 #ifdef CONFIG_CPU_MIPSR2
716 extern void spram_config(void);
717 #else
718 static inline void spram_config(void) {}
719 #endif
720 
721 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
722 {
723 	decode_configs(c);
724 	switch (c->processor_id & 0xff00) {
725 	case PRID_IMP_4KC:
726 		c->cputype = CPU_4KC;
727 		__cpu_name[cpu] = "MIPS 4Kc";
728 		break;
729 	case PRID_IMP_4KEC:
730 		c->cputype = CPU_4KEC;
731 		__cpu_name[cpu] = "MIPS 4KEc";
732 		break;
733 	case PRID_IMP_4KECR2:
734 		c->cputype = CPU_4KEC;
735 		__cpu_name[cpu] = "MIPS 4KEc";
736 		break;
737 	case PRID_IMP_4KSC:
738 	case PRID_IMP_4KSD:
739 		c->cputype = CPU_4KSC;
740 		__cpu_name[cpu] = "MIPS 4KSc";
741 		break;
742 	case PRID_IMP_5KC:
743 		c->cputype = CPU_5KC;
744 		__cpu_name[cpu] = "MIPS 5Kc";
745 		break;
746 	case PRID_IMP_20KC:
747 		c->cputype = CPU_20KC;
748 		__cpu_name[cpu] = "MIPS 20Kc";
749 		break;
750 	case PRID_IMP_24K:
751 	case PRID_IMP_24KE:
752 		c->cputype = CPU_24K;
753 		__cpu_name[cpu] = "MIPS 24Kc";
754 		break;
755 	case PRID_IMP_25KF:
756 		c->cputype = CPU_25KF;
757 		__cpu_name[cpu] = "MIPS 25Kc";
758 		break;
759 	case PRID_IMP_34K:
760 		c->cputype = CPU_34K;
761 		__cpu_name[cpu] = "MIPS 34Kc";
762 		break;
763 	case PRID_IMP_74K:
764 		c->cputype = CPU_74K;
765 		__cpu_name[cpu] = "MIPS 74Kc";
766 		break;
767 	case PRID_IMP_1004K:
768 		c->cputype = CPU_1004K;
769 		__cpu_name[cpu] = "MIPS 1004Kc";
770 		break;
771 	}
772 
773 	spram_config();
774 }
775 
776 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
777 {
778 	decode_configs(c);
779 	switch (c->processor_id & 0xff00) {
780 	case PRID_IMP_AU1_REV1:
781 	case PRID_IMP_AU1_REV2:
782 		switch ((c->processor_id >> 24) & 0xff) {
783 		case 0:
784 			c->cputype = CPU_AU1000;
785 			__cpu_name[cpu] = "Au1000";
786 			break;
787 		case 1:
788 			c->cputype = CPU_AU1500;
789 			__cpu_name[cpu] = "Au1500";
790 			break;
791 		case 2:
792 			c->cputype = CPU_AU1100;
793 			__cpu_name[cpu] = "Au1100";
794 			break;
795 		case 3:
796 			c->cputype = CPU_AU1550;
797 			__cpu_name[cpu] = "Au1550";
798 			break;
799 		case 4:
800 			c->cputype = CPU_AU1200;
801 			__cpu_name[cpu] = "Au1200";
802 			if ((c->processor_id & 0xff) == 2) {
803 				c->cputype = CPU_AU1250;
804 				__cpu_name[cpu] = "Au1250";
805 			}
806 			break;
807 		case 5:
808 			c->cputype = CPU_AU1210;
809 			__cpu_name[cpu] = "Au1210";
810 			break;
811 		default:
812 			panic("Unknown Au Core!");
813 			break;
814 		}
815 		break;
816 	}
817 }
818 
819 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
820 {
821 	decode_configs(c);
822 
823 	switch (c->processor_id & 0xff00) {
824 	case PRID_IMP_SB1:
825 		c->cputype = CPU_SB1;
826 		__cpu_name[cpu] = "SiByte SB1";
827 		/* FPU in pass1 is known to have issues. */
828 		if ((c->processor_id & 0xff) < 0x02)
829 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
830 		break;
831 	case PRID_IMP_SB1A:
832 		c->cputype = CPU_SB1A;
833 		__cpu_name[cpu] = "SiByte SB1A";
834 		break;
835 	}
836 }
837 
838 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
839 {
840 	decode_configs(c);
841 	switch (c->processor_id & 0xff00) {
842 	case PRID_IMP_SR71000:
843 		c->cputype = CPU_SR71000;
844 		__cpu_name[cpu] = "Sandcraft SR71000";
845 		c->scache.ways = 8;
846 		c->tlbsize = 64;
847 		break;
848 	}
849 }
850 
851 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
852 {
853 	decode_configs(c);
854 	switch (c->processor_id & 0xff00) {
855 	case PRID_IMP_PR4450:
856 		c->cputype = CPU_PR4450;
857 		__cpu_name[cpu] = "Philips PR4450";
858 		c->isa_level = MIPS_CPU_ISA_M32R1;
859 		break;
860 	}
861 }
862 
863 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
864 {
865 	decode_configs(c);
866 	switch (c->processor_id & 0xff00) {
867 	case PRID_IMP_BCM3302:
868 		c->cputype = CPU_BCM3302;
869 		__cpu_name[cpu] = "Broadcom BCM3302";
870 		break;
871 	case PRID_IMP_BCM4710:
872 		c->cputype = CPU_BCM4710;
873 		__cpu_name[cpu] = "Broadcom BCM4710";
874 		break;
875 	}
876 }
877 
878 const char *__cpu_name[NR_CPUS];
879 
880 __cpuinit void cpu_probe(void)
881 {
882 	struct cpuinfo_mips *c = &current_cpu_data;
883 	unsigned int cpu = smp_processor_id();
884 
885 	c->processor_id	= PRID_IMP_UNKNOWN;
886 	c->fpu_id	= FPIR_IMP_NONE;
887 	c->cputype	= CPU_UNKNOWN;
888 
889 	c->processor_id = read_c0_prid();
890 	switch (c->processor_id & 0xff0000) {
891 	case PRID_COMP_LEGACY:
892 		cpu_probe_legacy(c, cpu);
893 		break;
894 	case PRID_COMP_MIPS:
895 		cpu_probe_mips(c, cpu);
896 		break;
897 	case PRID_COMP_ALCHEMY:
898 		cpu_probe_alchemy(c, cpu);
899 		break;
900 	case PRID_COMP_SIBYTE:
901 		cpu_probe_sibyte(c, cpu);
902 		break;
903 	case PRID_COMP_BROADCOM:
904 		cpu_probe_broadcom(c, cpu);
905 		break;
906 	case PRID_COMP_SANDCRAFT:
907 		cpu_probe_sandcraft(c, cpu);
908 		break;
909 	case PRID_COMP_NXP:
910 		cpu_probe_nxp(c, cpu);
911 		break;
912 	}
913 
914 	BUG_ON(!__cpu_name[cpu]);
915 	BUG_ON(c->cputype == CPU_UNKNOWN);
916 
917 	/*
918 	 * Platform code can force the cpu type to optimize code
919 	 * generation. In that case be sure the cpu type is correctly
920 	 * manually setup otherwise it could trigger some nasty bugs.
921 	 */
922 	BUG_ON(current_cpu_type() != c->cputype);
923 
924 	if (c->options & MIPS_CPU_FPU) {
925 		c->fpu_id = cpu_get_fpu_id();
926 
927 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
928 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
929 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
930 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
931 			if (c->fpu_id & MIPS_FPIR_3D)
932 				c->ases |= MIPS_ASE_MIPS3D;
933 		}
934 	}
935 
936 	if (cpu_has_mips_r2)
937 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
938 	else
939 		c->srsets = 1;
940 }
941 
942 __cpuinit void cpu_report(void)
943 {
944 	struct cpuinfo_mips *c = &current_cpu_data;
945 
946 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
947 	       c->processor_id, cpu_name_string());
948 	if (c->options & MIPS_CPU_FPU)
949 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
950 }
951