xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 7dd65feb)
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/smp.h>
18 #include <linux/stddef.h>
19 #include <linux/module.h>
20 
21 #include <asm/bugs.h>
22 #include <asm/cpu.h>
23 #include <asm/fpu.h>
24 #include <asm/mipsregs.h>
25 #include <asm/system.h>
26 #include <asm/watch.h>
27 #include <asm/spram.h>
28 /*
29  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
30  * the implementation of the "wait" feature differs between CPU families. This
31  * points to the function that implements CPU specific wait.
32  * The wait instruction stops the pipeline and reduces the power consumption of
33  * the CPU very much.
34  */
35 void (*cpu_wait)(void);
36 EXPORT_SYMBOL(cpu_wait);
37 
38 static void r3081_wait(void)
39 {
40 	unsigned long cfg = read_c0_conf();
41 	write_c0_conf(cfg | R30XX_CONF_HALT);
42 }
43 
44 static void r39xx_wait(void)
45 {
46 	local_irq_disable();
47 	if (!need_resched())
48 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
49 	local_irq_enable();
50 }
51 
52 extern void r4k_wait(void);
53 
54 /*
55  * This variant is preferable as it allows testing need_resched and going to
56  * sleep depending on the outcome atomically.  Unfortunately the "It is
57  * implementation-dependent whether the pipeline restarts when a non-enabled
58  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
59  * using this version a gamble.
60  */
61 void r4k_wait_irqoff(void)
62 {
63 	local_irq_disable();
64 	if (!need_resched())
65 		__asm__("	.set	push		\n"
66 			"	.set	mips3		\n"
67 			"	wait			\n"
68 			"	.set	pop		\n");
69 	local_irq_enable();
70 	__asm__(" 	.globl __pastwait	\n"
71 		"__pastwait:			\n");
72 	return;
73 }
74 
75 /*
76  * The RM7000 variant has to handle erratum 38.  The workaround is to not
77  * have any pending stores when the WAIT instruction is executed.
78  */
79 static void rm7k_wait_irqoff(void)
80 {
81 	local_irq_disable();
82 	if (!need_resched())
83 		__asm__(
84 		"	.set	push					\n"
85 		"	.set	mips3					\n"
86 		"	.set	noat					\n"
87 		"	mfc0	$1, $12					\n"
88 		"	sync						\n"
89 		"	mtc0	$1, $12		# stalls until W stage	\n"
90 		"	wait						\n"
91 		"	mtc0	$1, $12		# stalls until W stage	\n"
92 		"	.set	pop					\n");
93 	local_irq_enable();
94 }
95 
96 /*
97  * The Au1xxx wait is available only if using 32khz counter or
98  * external timer source, but specifically not CP0 Counter.
99  * alchemy/common/time.c may override cpu_wait!
100  */
101 static void au1k_wait(void)
102 {
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;
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_R5500:
153 	case CPU_NEVADA:
154 	case CPU_4KC:
155 	case CPU_4KEC:
156 	case CPU_4KSC:
157 	case CPU_5KC:
158 	case CPU_25KF:
159 	case CPU_PR4450:
160 	case CPU_BCM3302:
161 	case CPU_BCM6338:
162 	case CPU_BCM6348:
163 	case CPU_BCM6358:
164 	case CPU_CAVIUM_OCTEON:
165 		cpu_wait = r4k_wait;
166 		break;
167 
168 	case CPU_RM7000:
169 		cpu_wait = rm7k_wait_irqoff;
170 		break;
171 
172 	case CPU_24K:
173 	case CPU_34K:
174 	case CPU_1004K:
175 		cpu_wait = r4k_wait;
176 		if (read_c0_config7() & MIPS_CONF7_WII)
177 			cpu_wait = r4k_wait_irqoff;
178 		break;
179 
180 	case CPU_74K:
181 		cpu_wait = r4k_wait;
182 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
183 			cpu_wait = r4k_wait_irqoff;
184 		break;
185 
186 	case CPU_TX49XX:
187 		cpu_wait = r4k_wait_irqoff;
188 		break;
189 	case CPU_ALCHEMY:
190 		cpu_wait = au1k_wait;
191 		break;
192 	case CPU_20KC:
193 		/*
194 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
195 		 * WAIT on Rev2.0 and Rev3.0 has E16.
196 		 * Rev3.1 WAIT is nop, why bother
197 		 */
198 		if ((c->processor_id & 0xff) <= 0x64)
199 			break;
200 
201 		/*
202 		 * Another rev is incremeting c0_count at a reduced clock
203 		 * rate while in WAIT mode.  So we basically have the choice
204 		 * between using the cp0 timer as clocksource or avoiding
205 		 * the WAIT instruction.  Until more details are known,
206 		 * disable the use of WAIT for 20Kc entirely.
207 		   cpu_wait = r4k_wait;
208 		 */
209 		break;
210 	case CPU_RM9000:
211 		if ((c->processor_id & 0x00ff) >= 0x40)
212 			cpu_wait = r4k_wait;
213 		break;
214 	default:
215 		break;
216 	}
217 }
218 
219 static inline void check_errata(void)
220 {
221 	struct cpuinfo_mips *c = &current_cpu_data;
222 
223 	switch (c->cputype) {
224 	case CPU_34K:
225 		/*
226 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
227 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
228 		 * making use of VPE1 will be responsable for that VPE.
229 		 */
230 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
231 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
232 		break;
233 	default:
234 		break;
235 	}
236 }
237 
238 void __init check_bugs32(void)
239 {
240 	check_errata();
241 }
242 
243 /*
244  * Probe whether cpu has config register by trying to play with
245  * alternate cache bit and see whether it matters.
246  * It's used by cpu_probe to distinguish between R3000A and R3081.
247  */
248 static inline int cpu_has_confreg(void)
249 {
250 #ifdef CONFIG_CPU_R3000
251 	extern unsigned long r3k_cache_size(unsigned long);
252 	unsigned long size1, size2;
253 	unsigned long cfg = read_c0_conf();
254 
255 	size1 = r3k_cache_size(ST0_ISC);
256 	write_c0_conf(cfg ^ R30XX_CONF_AC);
257 	size2 = r3k_cache_size(ST0_ISC);
258 	write_c0_conf(cfg);
259 	return size1 != size2;
260 #else
261 	return 0;
262 #endif
263 }
264 
265 /*
266  * Get the FPU Implementation/Revision.
267  */
268 static inline unsigned long cpu_get_fpu_id(void)
269 {
270 	unsigned long tmp, fpu_id;
271 
272 	tmp = read_c0_status();
273 	__enable_fpu();
274 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
275 	write_c0_status(tmp);
276 	return fpu_id;
277 }
278 
279 /*
280  * Check the CPU has an FPU the official way.
281  */
282 static inline int __cpu_has_fpu(void)
283 {
284 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
285 }
286 
287 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
288 		| MIPS_CPU_COUNTER)
289 
290 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
291 {
292 	switch (c->processor_id & 0xff00) {
293 	case PRID_IMP_R2000:
294 		c->cputype = CPU_R2000;
295 		__cpu_name[cpu] = "R2000";
296 		c->isa_level = MIPS_CPU_ISA_I;
297 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
298 		             MIPS_CPU_NOFPUEX;
299 		if (__cpu_has_fpu())
300 			c->options |= MIPS_CPU_FPU;
301 		c->tlbsize = 64;
302 		break;
303 	case PRID_IMP_R3000:
304 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
305 			if (cpu_has_confreg()) {
306 				c->cputype = CPU_R3081E;
307 				__cpu_name[cpu] = "R3081";
308 			} else {
309 				c->cputype = CPU_R3000A;
310 				__cpu_name[cpu] = "R3000A";
311 			}
312 			break;
313 		} else {
314 			c->cputype = CPU_R3000;
315 			__cpu_name[cpu] = "R3000";
316 		}
317 		c->isa_level = MIPS_CPU_ISA_I;
318 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
319 		             MIPS_CPU_NOFPUEX;
320 		if (__cpu_has_fpu())
321 			c->options |= MIPS_CPU_FPU;
322 		c->tlbsize = 64;
323 		break;
324 	case PRID_IMP_R4000:
325 		if (read_c0_config() & CONF_SC) {
326 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
327 				c->cputype = CPU_R4400PC;
328 				__cpu_name[cpu] = "R4400PC";
329 			} else {
330 				c->cputype = CPU_R4000PC;
331 				__cpu_name[cpu] = "R4000PC";
332 			}
333 		} else {
334 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
335 				c->cputype = CPU_R4400SC;
336 				__cpu_name[cpu] = "R4400SC";
337 			} else {
338 				c->cputype = CPU_R4000SC;
339 				__cpu_name[cpu] = "R4000SC";
340 			}
341 		}
342 
343 		c->isa_level = MIPS_CPU_ISA_III;
344 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
345 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
346 		             MIPS_CPU_LLSC;
347 		c->tlbsize = 48;
348 		break;
349 	case PRID_IMP_VR41XX:
350 		switch (c->processor_id & 0xf0) {
351 		case PRID_REV_VR4111:
352 			c->cputype = CPU_VR4111;
353 			__cpu_name[cpu] = "NEC VR4111";
354 			break;
355 		case PRID_REV_VR4121:
356 			c->cputype = CPU_VR4121;
357 			__cpu_name[cpu] = "NEC VR4121";
358 			break;
359 		case PRID_REV_VR4122:
360 			if ((c->processor_id & 0xf) < 0x3) {
361 				c->cputype = CPU_VR4122;
362 				__cpu_name[cpu] = "NEC VR4122";
363 			} else {
364 				c->cputype = CPU_VR4181A;
365 				__cpu_name[cpu] = "NEC VR4181A";
366 			}
367 			break;
368 		case PRID_REV_VR4130:
369 			if ((c->processor_id & 0xf) < 0x4) {
370 				c->cputype = CPU_VR4131;
371 				__cpu_name[cpu] = "NEC VR4131";
372 			} else {
373 				c->cputype = CPU_VR4133;
374 				__cpu_name[cpu] = "NEC VR4133";
375 			}
376 			break;
377 		default:
378 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
379 			c->cputype = CPU_VR41XX;
380 			__cpu_name[cpu] = "NEC Vr41xx";
381 			break;
382 		}
383 		c->isa_level = MIPS_CPU_ISA_III;
384 		c->options = R4K_OPTS;
385 		c->tlbsize = 32;
386 		break;
387 	case PRID_IMP_R4300:
388 		c->cputype = CPU_R4300;
389 		__cpu_name[cpu] = "R4300";
390 		c->isa_level = MIPS_CPU_ISA_III;
391 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
392 		             MIPS_CPU_LLSC;
393 		c->tlbsize = 32;
394 		break;
395 	case PRID_IMP_R4600:
396 		c->cputype = CPU_R4600;
397 		__cpu_name[cpu] = "R4600";
398 		c->isa_level = MIPS_CPU_ISA_III;
399 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
400 			     MIPS_CPU_LLSC;
401 		c->tlbsize = 48;
402 		break;
403 	#if 0
404  	case PRID_IMP_R4650:
405 		/*
406 		 * This processor doesn't have an MMU, so it's not
407 		 * "real easy" to run Linux on it. It is left purely
408 		 * for documentation.  Commented out because it shares
409 		 * it's c0_prid id number with the TX3900.
410 		 */
411 		c->cputype = CPU_R4650;
412 		__cpu_name[cpu] = "R4650";
413 	 	c->isa_level = MIPS_CPU_ISA_III;
414 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
415 	        c->tlbsize = 48;
416 		break;
417 	#endif
418 	case PRID_IMP_TX39:
419 		c->isa_level = MIPS_CPU_ISA_I;
420 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
421 
422 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
423 			c->cputype = CPU_TX3927;
424 			__cpu_name[cpu] = "TX3927";
425 			c->tlbsize = 64;
426 		} else {
427 			switch (c->processor_id & 0xff) {
428 			case PRID_REV_TX3912:
429 				c->cputype = CPU_TX3912;
430 				__cpu_name[cpu] = "TX3912";
431 				c->tlbsize = 32;
432 				break;
433 			case PRID_REV_TX3922:
434 				c->cputype = CPU_TX3922;
435 				__cpu_name[cpu] = "TX3922";
436 				c->tlbsize = 64;
437 				break;
438 			}
439 		}
440 		break;
441 	case PRID_IMP_R4700:
442 		c->cputype = CPU_R4700;
443 		__cpu_name[cpu] = "R4700";
444 		c->isa_level = MIPS_CPU_ISA_III;
445 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
446 		             MIPS_CPU_LLSC;
447 		c->tlbsize = 48;
448 		break;
449 	case PRID_IMP_TX49:
450 		c->cputype = CPU_TX49XX;
451 		__cpu_name[cpu] = "R49XX";
452 		c->isa_level = MIPS_CPU_ISA_III;
453 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
454 		if (!(c->processor_id & 0x08))
455 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
456 		c->tlbsize = 48;
457 		break;
458 	case PRID_IMP_R5000:
459 		c->cputype = CPU_R5000;
460 		__cpu_name[cpu] = "R5000";
461 		c->isa_level = MIPS_CPU_ISA_IV;
462 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
463 		             MIPS_CPU_LLSC;
464 		c->tlbsize = 48;
465 		break;
466 	case PRID_IMP_R5432:
467 		c->cputype = CPU_R5432;
468 		__cpu_name[cpu] = "R5432";
469 		c->isa_level = MIPS_CPU_ISA_IV;
470 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
471 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
472 		c->tlbsize = 48;
473 		break;
474 	case PRID_IMP_R5500:
475 		c->cputype = CPU_R5500;
476 		__cpu_name[cpu] = "R5500";
477 		c->isa_level = MIPS_CPU_ISA_IV;
478 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
479 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
480 		c->tlbsize = 48;
481 		break;
482 	case PRID_IMP_NEVADA:
483 		c->cputype = CPU_NEVADA;
484 		__cpu_name[cpu] = "Nevada";
485 		c->isa_level = MIPS_CPU_ISA_IV;
486 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
487 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
488 		c->tlbsize = 48;
489 		break;
490 	case PRID_IMP_R6000:
491 		c->cputype = CPU_R6000;
492 		__cpu_name[cpu] = "R6000";
493 		c->isa_level = MIPS_CPU_ISA_II;
494 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
495 		             MIPS_CPU_LLSC;
496 		c->tlbsize = 32;
497 		break;
498 	case PRID_IMP_R6000A:
499 		c->cputype = CPU_R6000A;
500 		__cpu_name[cpu] = "R6000A";
501 		c->isa_level = MIPS_CPU_ISA_II;
502 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
503 		             MIPS_CPU_LLSC;
504 		c->tlbsize = 32;
505 		break;
506 	case PRID_IMP_RM7000:
507 		c->cputype = CPU_RM7000;
508 		__cpu_name[cpu] = "RM7000";
509 		c->isa_level = MIPS_CPU_ISA_IV;
510 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
511 		             MIPS_CPU_LLSC;
512 		/*
513 		 * Undocumented RM7000:  Bit 29 in the info register of
514 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
515 		 * entries.
516 		 *
517 		 * 29      1 =>    64 entry JTLB
518 		 *         0 =>    48 entry JTLB
519 		 */
520 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
521 		break;
522 	case PRID_IMP_RM9000:
523 		c->cputype = CPU_RM9000;
524 		__cpu_name[cpu] = "RM9000";
525 		c->isa_level = MIPS_CPU_ISA_IV;
526 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
527 		             MIPS_CPU_LLSC;
528 		/*
529 		 * Bit 29 in the info register of the RM9000
530 		 * indicates if the TLB has 48 or 64 entries.
531 		 *
532 		 * 29      1 =>    64 entry JTLB
533 		 *         0 =>    48 entry JTLB
534 		 */
535 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
536 		break;
537 	case PRID_IMP_R8000:
538 		c->cputype = CPU_R8000;
539 		__cpu_name[cpu] = "RM8000";
540 		c->isa_level = MIPS_CPU_ISA_IV;
541 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
542 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
543 		             MIPS_CPU_LLSC;
544 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
545 		break;
546 	case PRID_IMP_R10000:
547 		c->cputype = CPU_R10000;
548 		__cpu_name[cpu] = "R10000";
549 		c->isa_level = MIPS_CPU_ISA_IV;
550 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
551 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
552 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
553 		             MIPS_CPU_LLSC;
554 		c->tlbsize = 64;
555 		break;
556 	case PRID_IMP_R12000:
557 		c->cputype = CPU_R12000;
558 		__cpu_name[cpu] = "R12000";
559 		c->isa_level = MIPS_CPU_ISA_IV;
560 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
561 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
562 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
563 		             MIPS_CPU_LLSC;
564 		c->tlbsize = 64;
565 		break;
566 	case PRID_IMP_R14000:
567 		c->cputype = CPU_R14000;
568 		__cpu_name[cpu] = "R14000";
569 		c->isa_level = MIPS_CPU_ISA_IV;
570 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
571 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
572 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
573 		             MIPS_CPU_LLSC;
574 		c->tlbsize = 64;
575 		break;
576 	case PRID_IMP_LOONGSON2:
577 		c->cputype = CPU_LOONGSON2;
578 		__cpu_name[cpu] = "ICT Loongson-2";
579 		c->isa_level = MIPS_CPU_ISA_III;
580 		c->options = R4K_OPTS |
581 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
582 			     MIPS_CPU_32FPR;
583 		c->tlbsize = 64;
584 		break;
585 	}
586 }
587 
588 static char unknown_isa[] __cpuinitdata = KERN_ERR \
589 	"Unsupported ISA type, c0.config0: %d.";
590 
591 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
592 {
593 	unsigned int config0;
594 	int isa;
595 
596 	config0 = read_c0_config();
597 
598 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
599 		c->options |= MIPS_CPU_TLB;
600 	isa = (config0 & MIPS_CONF_AT) >> 13;
601 	switch (isa) {
602 	case 0:
603 		switch ((config0 & MIPS_CONF_AR) >> 10) {
604 		case 0:
605 			c->isa_level = MIPS_CPU_ISA_M32R1;
606 			break;
607 		case 1:
608 			c->isa_level = MIPS_CPU_ISA_M32R2;
609 			break;
610 		default:
611 			goto unknown;
612 		}
613 		break;
614 	case 2:
615 		switch ((config0 & MIPS_CONF_AR) >> 10) {
616 		case 0:
617 			c->isa_level = MIPS_CPU_ISA_M64R1;
618 			break;
619 		case 1:
620 			c->isa_level = MIPS_CPU_ISA_M64R2;
621 			break;
622 		default:
623 			goto unknown;
624 		}
625 		break;
626 	default:
627 		goto unknown;
628 	}
629 
630 	return config0 & MIPS_CONF_M;
631 
632 unknown:
633 	panic(unknown_isa, config0);
634 }
635 
636 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
637 {
638 	unsigned int config1;
639 
640 	config1 = read_c0_config1();
641 
642 	if (config1 & MIPS_CONF1_MD)
643 		c->ases |= MIPS_ASE_MDMX;
644 	if (config1 & MIPS_CONF1_WR)
645 		c->options |= MIPS_CPU_WATCH;
646 	if (config1 & MIPS_CONF1_CA)
647 		c->ases |= MIPS_ASE_MIPS16;
648 	if (config1 & MIPS_CONF1_EP)
649 		c->options |= MIPS_CPU_EJTAG;
650 	if (config1 & MIPS_CONF1_FP) {
651 		c->options |= MIPS_CPU_FPU;
652 		c->options |= MIPS_CPU_32FPR;
653 	}
654 	if (cpu_has_tlb)
655 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
656 
657 	return config1 & MIPS_CONF_M;
658 }
659 
660 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
661 {
662 	unsigned int config2;
663 
664 	config2 = read_c0_config2();
665 
666 	if (config2 & MIPS_CONF2_SL)
667 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
668 
669 	return config2 & MIPS_CONF_M;
670 }
671 
672 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
673 {
674 	unsigned int config3;
675 
676 	config3 = read_c0_config3();
677 
678 	if (config3 & MIPS_CONF3_SM)
679 		c->ases |= MIPS_ASE_SMARTMIPS;
680 	if (config3 & MIPS_CONF3_DSP)
681 		c->ases |= MIPS_ASE_DSP;
682 	if (config3 & MIPS_CONF3_VINT)
683 		c->options |= MIPS_CPU_VINT;
684 	if (config3 & MIPS_CONF3_VEIC)
685 		c->options |= MIPS_CPU_VEIC;
686 	if (config3 & MIPS_CONF3_MT)
687 	        c->ases |= MIPS_ASE_MIPSMT;
688 	if (config3 & MIPS_CONF3_ULRI)
689 		c->options |= MIPS_CPU_ULRI;
690 
691 	return config3 & MIPS_CONF_M;
692 }
693 
694 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
695 {
696 	int ok;
697 
698 	/* MIPS32 or MIPS64 compliant CPU.  */
699 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
700 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
701 
702 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
703 
704 	ok = decode_config0(c);			/* Read Config registers.  */
705 	BUG_ON(!ok);				/* Arch spec violation!  */
706 	if (ok)
707 		ok = decode_config1(c);
708 	if (ok)
709 		ok = decode_config2(c);
710 	if (ok)
711 		ok = decode_config3(c);
712 
713 	mips_probe_watch_registers(c);
714 }
715 
716 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
717 {
718 	decode_configs(c);
719 	switch (c->processor_id & 0xff00) {
720 	case PRID_IMP_4KC:
721 		c->cputype = CPU_4KC;
722 		__cpu_name[cpu] = "MIPS 4Kc";
723 		break;
724 	case PRID_IMP_4KEC:
725 		c->cputype = CPU_4KEC;
726 		__cpu_name[cpu] = "MIPS 4KEc";
727 		break;
728 	case PRID_IMP_4KECR2:
729 		c->cputype = CPU_4KEC;
730 		__cpu_name[cpu] = "MIPS 4KEc";
731 		break;
732 	case PRID_IMP_4KSC:
733 	case PRID_IMP_4KSD:
734 		c->cputype = CPU_4KSC;
735 		__cpu_name[cpu] = "MIPS 4KSc";
736 		break;
737 	case PRID_IMP_5KC:
738 		c->cputype = CPU_5KC;
739 		__cpu_name[cpu] = "MIPS 5Kc";
740 		break;
741 	case PRID_IMP_20KC:
742 		c->cputype = CPU_20KC;
743 		__cpu_name[cpu] = "MIPS 20Kc";
744 		break;
745 	case PRID_IMP_24K:
746 	case PRID_IMP_24KE:
747 		c->cputype = CPU_24K;
748 		__cpu_name[cpu] = "MIPS 24Kc";
749 		break;
750 	case PRID_IMP_25KF:
751 		c->cputype = CPU_25KF;
752 		__cpu_name[cpu] = "MIPS 25Kc";
753 		break;
754 	case PRID_IMP_34K:
755 		c->cputype = CPU_34K;
756 		__cpu_name[cpu] = "MIPS 34Kc";
757 		break;
758 	case PRID_IMP_74K:
759 		c->cputype = CPU_74K;
760 		__cpu_name[cpu] = "MIPS 74Kc";
761 		break;
762 	case PRID_IMP_1004K:
763 		c->cputype = CPU_1004K;
764 		__cpu_name[cpu] = "MIPS 1004Kc";
765 		break;
766 	}
767 
768 	spram_config();
769 }
770 
771 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
772 {
773 	decode_configs(c);
774 	switch (c->processor_id & 0xff00) {
775 	case PRID_IMP_AU1_REV1:
776 	case PRID_IMP_AU1_REV2:
777 		c->cputype = CPU_ALCHEMY;
778 		switch ((c->processor_id >> 24) & 0xff) {
779 		case 0:
780 			__cpu_name[cpu] = "Au1000";
781 			break;
782 		case 1:
783 			__cpu_name[cpu] = "Au1500";
784 			break;
785 		case 2:
786 			__cpu_name[cpu] = "Au1100";
787 			break;
788 		case 3:
789 			__cpu_name[cpu] = "Au1550";
790 			break;
791 		case 4:
792 			__cpu_name[cpu] = "Au1200";
793 			if ((c->processor_id & 0xff) == 2)
794 				__cpu_name[cpu] = "Au1250";
795 			break;
796 		case 5:
797 			__cpu_name[cpu] = "Au1210";
798 			break;
799 		default:
800 			__cpu_name[cpu] = "Au1xxx";
801 			break;
802 		}
803 		break;
804 	}
805 }
806 
807 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
808 {
809 	decode_configs(c);
810 
811 	switch (c->processor_id & 0xff00) {
812 	case PRID_IMP_SB1:
813 		c->cputype = CPU_SB1;
814 		__cpu_name[cpu] = "SiByte SB1";
815 		/* FPU in pass1 is known to have issues. */
816 		if ((c->processor_id & 0xff) < 0x02)
817 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
818 		break;
819 	case PRID_IMP_SB1A:
820 		c->cputype = CPU_SB1A;
821 		__cpu_name[cpu] = "SiByte SB1A";
822 		break;
823 	}
824 }
825 
826 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
827 {
828 	decode_configs(c);
829 	switch (c->processor_id & 0xff00) {
830 	case PRID_IMP_SR71000:
831 		c->cputype = CPU_SR71000;
832 		__cpu_name[cpu] = "Sandcraft SR71000";
833 		c->scache.ways = 8;
834 		c->tlbsize = 64;
835 		break;
836 	}
837 }
838 
839 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
840 {
841 	decode_configs(c);
842 	switch (c->processor_id & 0xff00) {
843 	case PRID_IMP_PR4450:
844 		c->cputype = CPU_PR4450;
845 		__cpu_name[cpu] = "Philips PR4450";
846 		c->isa_level = MIPS_CPU_ISA_M32R1;
847 		break;
848 	}
849 }
850 
851 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
852 {
853 	decode_configs(c);
854 	switch (c->processor_id & 0xff00) {
855 	case PRID_IMP_BCM3302:
856 	 /* same as PRID_IMP_BCM6338 */
857 		c->cputype = CPU_BCM3302;
858 		__cpu_name[cpu] = "Broadcom BCM3302";
859 		break;
860 	case PRID_IMP_BCM4710:
861 		c->cputype = CPU_BCM4710;
862 		__cpu_name[cpu] = "Broadcom BCM4710";
863 		break;
864 	case PRID_IMP_BCM6345:
865 		c->cputype = CPU_BCM6345;
866 		__cpu_name[cpu] = "Broadcom BCM6345";
867 		break;
868 	case PRID_IMP_BCM6348:
869 		c->cputype = CPU_BCM6348;
870 		__cpu_name[cpu] = "Broadcom BCM6348";
871 		break;
872 	case PRID_IMP_BCM4350:
873 		switch (c->processor_id & 0xf0) {
874 		case PRID_REV_BCM6358:
875 			c->cputype = CPU_BCM6358;
876 			__cpu_name[cpu] = "Broadcom BCM6358";
877 			break;
878 		default:
879 			c->cputype = CPU_UNKNOWN;
880 			break;
881 		}
882 		break;
883 	}
884 }
885 
886 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
887 {
888 	decode_configs(c);
889 	switch (c->processor_id & 0xff00) {
890 	case PRID_IMP_CAVIUM_CN38XX:
891 	case PRID_IMP_CAVIUM_CN31XX:
892 	case PRID_IMP_CAVIUM_CN30XX:
893 	case PRID_IMP_CAVIUM_CN58XX:
894 	case PRID_IMP_CAVIUM_CN56XX:
895 	case PRID_IMP_CAVIUM_CN50XX:
896 	case PRID_IMP_CAVIUM_CN52XX:
897 		c->cputype = CPU_CAVIUM_OCTEON;
898 		__cpu_name[cpu] = "Cavium Octeon";
899 		break;
900 	default:
901 		printk(KERN_INFO "Unknown Octeon chip!\n");
902 		c->cputype = CPU_UNKNOWN;
903 		break;
904 	}
905 }
906 
907 const char *__cpu_name[NR_CPUS];
908 
909 __cpuinit void cpu_probe(void)
910 {
911 	struct cpuinfo_mips *c = &current_cpu_data;
912 	unsigned int cpu = smp_processor_id();
913 
914 	c->processor_id	= PRID_IMP_UNKNOWN;
915 	c->fpu_id	= FPIR_IMP_NONE;
916 	c->cputype	= CPU_UNKNOWN;
917 
918 	c->processor_id = read_c0_prid();
919 	switch (c->processor_id & 0xff0000) {
920 	case PRID_COMP_LEGACY:
921 		cpu_probe_legacy(c, cpu);
922 		break;
923 	case PRID_COMP_MIPS:
924 		cpu_probe_mips(c, cpu);
925 		break;
926 	case PRID_COMP_ALCHEMY:
927 		cpu_probe_alchemy(c, cpu);
928 		break;
929 	case PRID_COMP_SIBYTE:
930 		cpu_probe_sibyte(c, cpu);
931 		break;
932 	case PRID_COMP_BROADCOM:
933 		cpu_probe_broadcom(c, cpu);
934 		break;
935 	case PRID_COMP_SANDCRAFT:
936 		cpu_probe_sandcraft(c, cpu);
937 		break;
938 	case PRID_COMP_NXP:
939 		cpu_probe_nxp(c, cpu);
940 		break;
941 	case PRID_COMP_CAVIUM:
942 		cpu_probe_cavium(c, cpu);
943 		break;
944 	}
945 
946 	BUG_ON(!__cpu_name[cpu]);
947 	BUG_ON(c->cputype == CPU_UNKNOWN);
948 
949 	/*
950 	 * Platform code can force the cpu type to optimize code
951 	 * generation. In that case be sure the cpu type is correctly
952 	 * manually setup otherwise it could trigger some nasty bugs.
953 	 */
954 	BUG_ON(current_cpu_type() != c->cputype);
955 
956 	if (c->options & MIPS_CPU_FPU) {
957 		c->fpu_id = cpu_get_fpu_id();
958 
959 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
960 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
961 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
962 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
963 			if (c->fpu_id & MIPS_FPIR_3D)
964 				c->ases |= MIPS_ASE_MIPS3D;
965 		}
966 	}
967 
968 	if (cpu_has_mips_r2)
969 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
970 	else
971 		c->srsets = 1;
972 }
973 
974 __cpuinit void cpu_report(void)
975 {
976 	struct cpuinfo_mips *c = &current_cpu_data;
977 
978 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
979 	       c->processor_id, cpu_name_string());
980 	if (c->options & MIPS_CPU_FPU)
981 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
982 }
983