xref: /linux/arch/mips/kernel/cpu-probe.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 	case CPU_CAVIUM_OCTEON_PLUS:
166 		cpu_wait = r4k_wait;
167 		break;
168 
169 	case CPU_RM7000:
170 		cpu_wait = rm7k_wait_irqoff;
171 		break;
172 
173 	case CPU_24K:
174 	case CPU_34K:
175 	case CPU_1004K:
176 		cpu_wait = r4k_wait;
177 		if (read_c0_config7() & MIPS_CONF7_WII)
178 			cpu_wait = r4k_wait_irqoff;
179 		break;
180 
181 	case CPU_74K:
182 		cpu_wait = r4k_wait;
183 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
184 			cpu_wait = r4k_wait_irqoff;
185 		break;
186 
187 	case CPU_TX49XX:
188 		cpu_wait = r4k_wait_irqoff;
189 		break;
190 	case CPU_ALCHEMY:
191 		cpu_wait = au1k_wait;
192 		break;
193 	case CPU_20KC:
194 		/*
195 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
196 		 * WAIT on Rev2.0 and Rev3.0 has E16.
197 		 * Rev3.1 WAIT is nop, why bother
198 		 */
199 		if ((c->processor_id & 0xff) <= 0x64)
200 			break;
201 
202 		/*
203 		 * Another rev is incremeting c0_count at a reduced clock
204 		 * rate while in WAIT mode.  So we basically have the choice
205 		 * between using the cp0 timer as clocksource or avoiding
206 		 * the WAIT instruction.  Until more details are known,
207 		 * disable the use of WAIT for 20Kc entirely.
208 		   cpu_wait = r4k_wait;
209 		 */
210 		break;
211 	case CPU_RM9000:
212 		if ((c->processor_id & 0x00ff) >= 0x40)
213 			cpu_wait = r4k_wait;
214 		break;
215 	default:
216 		break;
217 	}
218 }
219 
220 static inline void check_errata(void)
221 {
222 	struct cpuinfo_mips *c = &current_cpu_data;
223 
224 	switch (c->cputype) {
225 	case CPU_34K:
226 		/*
227 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
228 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
229 		 * making use of VPE1 will be responsable for that VPE.
230 		 */
231 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
232 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
233 		break;
234 	default:
235 		break;
236 	}
237 }
238 
239 void __init check_bugs32(void)
240 {
241 	check_errata();
242 }
243 
244 /*
245  * Probe whether cpu has config register by trying to play with
246  * alternate cache bit and see whether it matters.
247  * It's used by cpu_probe to distinguish between R3000A and R3081.
248  */
249 static inline int cpu_has_confreg(void)
250 {
251 #ifdef CONFIG_CPU_R3000
252 	extern unsigned long r3k_cache_size(unsigned long);
253 	unsigned long size1, size2;
254 	unsigned long cfg = read_c0_conf();
255 
256 	size1 = r3k_cache_size(ST0_ISC);
257 	write_c0_conf(cfg ^ R30XX_CONF_AC);
258 	size2 = r3k_cache_size(ST0_ISC);
259 	write_c0_conf(cfg);
260 	return size1 != size2;
261 #else
262 	return 0;
263 #endif
264 }
265 
266 /*
267  * Get the FPU Implementation/Revision.
268  */
269 static inline unsigned long cpu_get_fpu_id(void)
270 {
271 	unsigned long tmp, fpu_id;
272 
273 	tmp = read_c0_status();
274 	__enable_fpu();
275 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
276 	write_c0_status(tmp);
277 	return fpu_id;
278 }
279 
280 /*
281  * Check the CPU has an FPU the official way.
282  */
283 static inline int __cpu_has_fpu(void)
284 {
285 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
286 }
287 
288 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
289 {
290 #ifdef __NEED_VMBITS_PROBE
291 	write_c0_entryhi(0x3fffffffffffe000ULL);
292 	back_to_back_c0_hazard();
293 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
294 #endif
295 }
296 
297 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
298 		| MIPS_CPU_COUNTER)
299 
300 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
301 {
302 	switch (c->processor_id & 0xff00) {
303 	case PRID_IMP_R2000:
304 		c->cputype = CPU_R2000;
305 		__cpu_name[cpu] = "R2000";
306 		c->isa_level = MIPS_CPU_ISA_I;
307 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
308 		             MIPS_CPU_NOFPUEX;
309 		if (__cpu_has_fpu())
310 			c->options |= MIPS_CPU_FPU;
311 		c->tlbsize = 64;
312 		break;
313 	case PRID_IMP_R3000:
314 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
315 			if (cpu_has_confreg()) {
316 				c->cputype = CPU_R3081E;
317 				__cpu_name[cpu] = "R3081";
318 			} else {
319 				c->cputype = CPU_R3000A;
320 				__cpu_name[cpu] = "R3000A";
321 			}
322 			break;
323 		} else {
324 			c->cputype = CPU_R3000;
325 			__cpu_name[cpu] = "R3000";
326 		}
327 		c->isa_level = MIPS_CPU_ISA_I;
328 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
329 		             MIPS_CPU_NOFPUEX;
330 		if (__cpu_has_fpu())
331 			c->options |= MIPS_CPU_FPU;
332 		c->tlbsize = 64;
333 		break;
334 	case PRID_IMP_R4000:
335 		if (read_c0_config() & CONF_SC) {
336 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
337 				c->cputype = CPU_R4400PC;
338 				__cpu_name[cpu] = "R4400PC";
339 			} else {
340 				c->cputype = CPU_R4000PC;
341 				__cpu_name[cpu] = "R4000PC";
342 			}
343 		} else {
344 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
345 				c->cputype = CPU_R4400SC;
346 				__cpu_name[cpu] = "R4400SC";
347 			} else {
348 				c->cputype = CPU_R4000SC;
349 				__cpu_name[cpu] = "R4000SC";
350 			}
351 		}
352 
353 		c->isa_level = MIPS_CPU_ISA_III;
354 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
355 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
356 		             MIPS_CPU_LLSC;
357 		c->tlbsize = 48;
358 		break;
359 	case PRID_IMP_VR41XX:
360 		switch (c->processor_id & 0xf0) {
361 		case PRID_REV_VR4111:
362 			c->cputype = CPU_VR4111;
363 			__cpu_name[cpu] = "NEC VR4111";
364 			break;
365 		case PRID_REV_VR4121:
366 			c->cputype = CPU_VR4121;
367 			__cpu_name[cpu] = "NEC VR4121";
368 			break;
369 		case PRID_REV_VR4122:
370 			if ((c->processor_id & 0xf) < 0x3) {
371 				c->cputype = CPU_VR4122;
372 				__cpu_name[cpu] = "NEC VR4122";
373 			} else {
374 				c->cputype = CPU_VR4181A;
375 				__cpu_name[cpu] = "NEC VR4181A";
376 			}
377 			break;
378 		case PRID_REV_VR4130:
379 			if ((c->processor_id & 0xf) < 0x4) {
380 				c->cputype = CPU_VR4131;
381 				__cpu_name[cpu] = "NEC VR4131";
382 			} else {
383 				c->cputype = CPU_VR4133;
384 				__cpu_name[cpu] = "NEC VR4133";
385 			}
386 			break;
387 		default:
388 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
389 			c->cputype = CPU_VR41XX;
390 			__cpu_name[cpu] = "NEC Vr41xx";
391 			break;
392 		}
393 		c->isa_level = MIPS_CPU_ISA_III;
394 		c->options = R4K_OPTS;
395 		c->tlbsize = 32;
396 		break;
397 	case PRID_IMP_R4300:
398 		c->cputype = CPU_R4300;
399 		__cpu_name[cpu] = "R4300";
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 = 32;
404 		break;
405 	case PRID_IMP_R4600:
406 		c->cputype = CPU_R4600;
407 		__cpu_name[cpu] = "R4600";
408 		c->isa_level = MIPS_CPU_ISA_III;
409 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
410 			     MIPS_CPU_LLSC;
411 		c->tlbsize = 48;
412 		break;
413 	#if 0
414  	case PRID_IMP_R4650:
415 		/*
416 		 * This processor doesn't have an MMU, so it's not
417 		 * "real easy" to run Linux on it. It is left purely
418 		 * for documentation.  Commented out because it shares
419 		 * it's c0_prid id number with the TX3900.
420 		 */
421 		c->cputype = CPU_R4650;
422 		__cpu_name[cpu] = "R4650";
423 	 	c->isa_level = MIPS_CPU_ISA_III;
424 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
425 	        c->tlbsize = 48;
426 		break;
427 	#endif
428 	case PRID_IMP_TX39:
429 		c->isa_level = MIPS_CPU_ISA_I;
430 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
431 
432 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
433 			c->cputype = CPU_TX3927;
434 			__cpu_name[cpu] = "TX3927";
435 			c->tlbsize = 64;
436 		} else {
437 			switch (c->processor_id & 0xff) {
438 			case PRID_REV_TX3912:
439 				c->cputype = CPU_TX3912;
440 				__cpu_name[cpu] = "TX3912";
441 				c->tlbsize = 32;
442 				break;
443 			case PRID_REV_TX3922:
444 				c->cputype = CPU_TX3922;
445 				__cpu_name[cpu] = "TX3922";
446 				c->tlbsize = 64;
447 				break;
448 			}
449 		}
450 		break;
451 	case PRID_IMP_R4700:
452 		c->cputype = CPU_R4700;
453 		__cpu_name[cpu] = "R4700";
454 		c->isa_level = MIPS_CPU_ISA_III;
455 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
456 		             MIPS_CPU_LLSC;
457 		c->tlbsize = 48;
458 		break;
459 	case PRID_IMP_TX49:
460 		c->cputype = CPU_TX49XX;
461 		__cpu_name[cpu] = "R49XX";
462 		c->isa_level = MIPS_CPU_ISA_III;
463 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
464 		if (!(c->processor_id & 0x08))
465 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
466 		c->tlbsize = 48;
467 		break;
468 	case PRID_IMP_R5000:
469 		c->cputype = CPU_R5000;
470 		__cpu_name[cpu] = "R5000";
471 		c->isa_level = MIPS_CPU_ISA_IV;
472 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
473 		             MIPS_CPU_LLSC;
474 		c->tlbsize = 48;
475 		break;
476 	case PRID_IMP_R5432:
477 		c->cputype = CPU_R5432;
478 		__cpu_name[cpu] = "R5432";
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_R5500:
485 		c->cputype = CPU_R5500;
486 		__cpu_name[cpu] = "R5500";
487 		c->isa_level = MIPS_CPU_ISA_IV;
488 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
489 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
490 		c->tlbsize = 48;
491 		break;
492 	case PRID_IMP_NEVADA:
493 		c->cputype = CPU_NEVADA;
494 		__cpu_name[cpu] = "Nevada";
495 		c->isa_level = MIPS_CPU_ISA_IV;
496 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
497 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
498 		c->tlbsize = 48;
499 		break;
500 	case PRID_IMP_R6000:
501 		c->cputype = CPU_R6000;
502 		__cpu_name[cpu] = "R6000";
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_R6000A:
509 		c->cputype = CPU_R6000A;
510 		__cpu_name[cpu] = "R6000A";
511 		c->isa_level = MIPS_CPU_ISA_II;
512 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
513 		             MIPS_CPU_LLSC;
514 		c->tlbsize = 32;
515 		break;
516 	case PRID_IMP_RM7000:
517 		c->cputype = CPU_RM7000;
518 		__cpu_name[cpu] = "RM7000";
519 		c->isa_level = MIPS_CPU_ISA_IV;
520 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
521 		             MIPS_CPU_LLSC;
522 		/*
523 		 * Undocumented RM7000:  Bit 29 in the info register of
524 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
525 		 * entries.
526 		 *
527 		 * 29      1 =>    64 entry JTLB
528 		 *         0 =>    48 entry JTLB
529 		 */
530 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
531 		break;
532 	case PRID_IMP_RM9000:
533 		c->cputype = CPU_RM9000;
534 		__cpu_name[cpu] = "RM9000";
535 		c->isa_level = MIPS_CPU_ISA_IV;
536 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
537 		             MIPS_CPU_LLSC;
538 		/*
539 		 * Bit 29 in the info register of the RM9000
540 		 * indicates if the TLB has 48 or 64 entries.
541 		 *
542 		 * 29      1 =>    64 entry JTLB
543 		 *         0 =>    48 entry JTLB
544 		 */
545 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
546 		break;
547 	case PRID_IMP_R8000:
548 		c->cputype = CPU_R8000;
549 		__cpu_name[cpu] = "RM8000";
550 		c->isa_level = MIPS_CPU_ISA_IV;
551 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
552 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
553 		             MIPS_CPU_LLSC;
554 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
555 		break;
556 	case PRID_IMP_R10000:
557 		c->cputype = CPU_R10000;
558 		__cpu_name[cpu] = "R10000";
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_R12000:
567 		c->cputype = CPU_R12000;
568 		__cpu_name[cpu] = "R12000";
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_R14000:
577 		c->cputype = CPU_R14000;
578 		__cpu_name[cpu] = "R14000";
579 		c->isa_level = MIPS_CPU_ISA_IV;
580 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
581 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
582 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
583 		             MIPS_CPU_LLSC;
584 		c->tlbsize = 64;
585 		break;
586 	case PRID_IMP_LOONGSON2:
587 		c->cputype = CPU_LOONGSON2;
588 		__cpu_name[cpu] = "ICT Loongson-2";
589 		c->isa_level = MIPS_CPU_ISA_III;
590 		c->options = R4K_OPTS |
591 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
592 			     MIPS_CPU_32FPR;
593 		c->tlbsize = 64;
594 		break;
595 	}
596 }
597 
598 static char unknown_isa[] __cpuinitdata = KERN_ERR \
599 	"Unsupported ISA type, c0.config0: %d.";
600 
601 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
602 {
603 	unsigned int config0;
604 	int isa;
605 
606 	config0 = read_c0_config();
607 
608 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
609 		c->options |= MIPS_CPU_TLB;
610 	isa = (config0 & MIPS_CONF_AT) >> 13;
611 	switch (isa) {
612 	case 0:
613 		switch ((config0 & MIPS_CONF_AR) >> 10) {
614 		case 0:
615 			c->isa_level = MIPS_CPU_ISA_M32R1;
616 			break;
617 		case 1:
618 			c->isa_level = MIPS_CPU_ISA_M32R2;
619 			break;
620 		default:
621 			goto unknown;
622 		}
623 		break;
624 	case 2:
625 		switch ((config0 & MIPS_CONF_AR) >> 10) {
626 		case 0:
627 			c->isa_level = MIPS_CPU_ISA_M64R1;
628 			break;
629 		case 1:
630 			c->isa_level = MIPS_CPU_ISA_M64R2;
631 			break;
632 		default:
633 			goto unknown;
634 		}
635 		break;
636 	default:
637 		goto unknown;
638 	}
639 
640 	return config0 & MIPS_CONF_M;
641 
642 unknown:
643 	panic(unknown_isa, config0);
644 }
645 
646 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
647 {
648 	unsigned int config1;
649 
650 	config1 = read_c0_config1();
651 
652 	if (config1 & MIPS_CONF1_MD)
653 		c->ases |= MIPS_ASE_MDMX;
654 	if (config1 & MIPS_CONF1_WR)
655 		c->options |= MIPS_CPU_WATCH;
656 	if (config1 & MIPS_CONF1_CA)
657 		c->ases |= MIPS_ASE_MIPS16;
658 	if (config1 & MIPS_CONF1_EP)
659 		c->options |= MIPS_CPU_EJTAG;
660 	if (config1 & MIPS_CONF1_FP) {
661 		c->options |= MIPS_CPU_FPU;
662 		c->options |= MIPS_CPU_32FPR;
663 	}
664 	if (cpu_has_tlb)
665 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
666 
667 	return config1 & MIPS_CONF_M;
668 }
669 
670 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
671 {
672 	unsigned int config2;
673 
674 	config2 = read_c0_config2();
675 
676 	if (config2 & MIPS_CONF2_SL)
677 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
678 
679 	return config2 & MIPS_CONF_M;
680 }
681 
682 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
683 {
684 	unsigned int config3;
685 
686 	config3 = read_c0_config3();
687 
688 	if (config3 & MIPS_CONF3_SM)
689 		c->ases |= MIPS_ASE_SMARTMIPS;
690 	if (config3 & MIPS_CONF3_DSP)
691 		c->ases |= MIPS_ASE_DSP;
692 	if (config3 & MIPS_CONF3_VINT)
693 		c->options |= MIPS_CPU_VINT;
694 	if (config3 & MIPS_CONF3_VEIC)
695 		c->options |= MIPS_CPU_VEIC;
696 	if (config3 & MIPS_CONF3_MT)
697 	        c->ases |= MIPS_ASE_MIPSMT;
698 	if (config3 & MIPS_CONF3_ULRI)
699 		c->options |= MIPS_CPU_ULRI;
700 
701 	return config3 & MIPS_CONF_M;
702 }
703 
704 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
705 {
706 	unsigned int config4;
707 
708 	config4 = read_c0_config4();
709 
710 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
711 	    && cpu_has_tlb)
712 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
713 
714 	return config4 & MIPS_CONF_M;
715 }
716 
717 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
718 {
719 	int ok;
720 
721 	/* MIPS32 or MIPS64 compliant CPU.  */
722 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
723 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
724 
725 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
726 
727 	ok = decode_config0(c);			/* Read Config registers.  */
728 	BUG_ON(!ok);				/* Arch spec violation!  */
729 	if (ok)
730 		ok = decode_config1(c);
731 	if (ok)
732 		ok = decode_config2(c);
733 	if (ok)
734 		ok = decode_config3(c);
735 	if (ok)
736 		ok = decode_config4(c);
737 
738 	mips_probe_watch_registers(c);
739 }
740 
741 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
742 {
743 	decode_configs(c);
744 	switch (c->processor_id & 0xff00) {
745 	case PRID_IMP_4KC:
746 		c->cputype = CPU_4KC;
747 		__cpu_name[cpu] = "MIPS 4Kc";
748 		break;
749 	case PRID_IMP_4KEC:
750 	case PRID_IMP_4KECR2:
751 		c->cputype = CPU_4KEC;
752 		__cpu_name[cpu] = "MIPS 4KEc";
753 		break;
754 	case PRID_IMP_4KSC:
755 	case PRID_IMP_4KSD:
756 		c->cputype = CPU_4KSC;
757 		__cpu_name[cpu] = "MIPS 4KSc";
758 		break;
759 	case PRID_IMP_5KC:
760 		c->cputype = CPU_5KC;
761 		__cpu_name[cpu] = "MIPS 5Kc";
762 		break;
763 	case PRID_IMP_20KC:
764 		c->cputype = CPU_20KC;
765 		__cpu_name[cpu] = "MIPS 20Kc";
766 		break;
767 	case PRID_IMP_24K:
768 	case PRID_IMP_24KE:
769 		c->cputype = CPU_24K;
770 		__cpu_name[cpu] = "MIPS 24Kc";
771 		break;
772 	case PRID_IMP_25KF:
773 		c->cputype = CPU_25KF;
774 		__cpu_name[cpu] = "MIPS 25Kc";
775 		break;
776 	case PRID_IMP_34K:
777 		c->cputype = CPU_34K;
778 		__cpu_name[cpu] = "MIPS 34Kc";
779 		break;
780 	case PRID_IMP_74K:
781 		c->cputype = CPU_74K;
782 		__cpu_name[cpu] = "MIPS 74Kc";
783 		break;
784 	case PRID_IMP_1004K:
785 		c->cputype = CPU_1004K;
786 		__cpu_name[cpu] = "MIPS 1004Kc";
787 		break;
788 	}
789 
790 	spram_config();
791 }
792 
793 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
794 {
795 	decode_configs(c);
796 	switch (c->processor_id & 0xff00) {
797 	case PRID_IMP_AU1_REV1:
798 	case PRID_IMP_AU1_REV2:
799 		c->cputype = CPU_ALCHEMY;
800 		switch ((c->processor_id >> 24) & 0xff) {
801 		case 0:
802 			__cpu_name[cpu] = "Au1000";
803 			break;
804 		case 1:
805 			__cpu_name[cpu] = "Au1500";
806 			break;
807 		case 2:
808 			__cpu_name[cpu] = "Au1100";
809 			break;
810 		case 3:
811 			__cpu_name[cpu] = "Au1550";
812 			break;
813 		case 4:
814 			__cpu_name[cpu] = "Au1200";
815 			if ((c->processor_id & 0xff) == 2)
816 				__cpu_name[cpu] = "Au1250";
817 			break;
818 		case 5:
819 			__cpu_name[cpu] = "Au1210";
820 			break;
821 		default:
822 			__cpu_name[cpu] = "Au1xxx";
823 			break;
824 		}
825 		break;
826 	}
827 }
828 
829 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
830 {
831 	decode_configs(c);
832 
833 	switch (c->processor_id & 0xff00) {
834 	case PRID_IMP_SB1:
835 		c->cputype = CPU_SB1;
836 		__cpu_name[cpu] = "SiByte SB1";
837 		/* FPU in pass1 is known to have issues. */
838 		if ((c->processor_id & 0xff) < 0x02)
839 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
840 		break;
841 	case PRID_IMP_SB1A:
842 		c->cputype = CPU_SB1A;
843 		__cpu_name[cpu] = "SiByte SB1A";
844 		break;
845 	}
846 }
847 
848 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
849 {
850 	decode_configs(c);
851 	switch (c->processor_id & 0xff00) {
852 	case PRID_IMP_SR71000:
853 		c->cputype = CPU_SR71000;
854 		__cpu_name[cpu] = "Sandcraft SR71000";
855 		c->scache.ways = 8;
856 		c->tlbsize = 64;
857 		break;
858 	}
859 }
860 
861 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
862 {
863 	decode_configs(c);
864 	switch (c->processor_id & 0xff00) {
865 	case PRID_IMP_PR4450:
866 		c->cputype = CPU_PR4450;
867 		__cpu_name[cpu] = "Philips PR4450";
868 		c->isa_level = MIPS_CPU_ISA_M32R1;
869 		break;
870 	}
871 }
872 
873 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
874 {
875 	decode_configs(c);
876 	switch (c->processor_id & 0xff00) {
877 	case PRID_IMP_BCM3302:
878 	 /* same as PRID_IMP_BCM6338 */
879 		c->cputype = CPU_BCM3302;
880 		__cpu_name[cpu] = "Broadcom BCM3302";
881 		break;
882 	case PRID_IMP_BCM4710:
883 		c->cputype = CPU_BCM4710;
884 		__cpu_name[cpu] = "Broadcom BCM4710";
885 		break;
886 	case PRID_IMP_BCM6345:
887 		c->cputype = CPU_BCM6345;
888 		__cpu_name[cpu] = "Broadcom BCM6345";
889 		break;
890 	case PRID_IMP_BCM6348:
891 		c->cputype = CPU_BCM6348;
892 		__cpu_name[cpu] = "Broadcom BCM6348";
893 		break;
894 	case PRID_IMP_BCM4350:
895 		switch (c->processor_id & 0xf0) {
896 		case PRID_REV_BCM6358:
897 			c->cputype = CPU_BCM6358;
898 			__cpu_name[cpu] = "Broadcom BCM6358";
899 			break;
900 		default:
901 			c->cputype = CPU_UNKNOWN;
902 			break;
903 		}
904 		break;
905 	}
906 }
907 
908 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
909 {
910 	decode_configs(c);
911 	switch (c->processor_id & 0xff00) {
912 	case PRID_IMP_CAVIUM_CN38XX:
913 	case PRID_IMP_CAVIUM_CN31XX:
914 	case PRID_IMP_CAVIUM_CN30XX:
915 		c->cputype = CPU_CAVIUM_OCTEON;
916 		__cpu_name[cpu] = "Cavium Octeon";
917 		goto platform;
918 	case PRID_IMP_CAVIUM_CN58XX:
919 	case PRID_IMP_CAVIUM_CN56XX:
920 	case PRID_IMP_CAVIUM_CN50XX:
921 	case PRID_IMP_CAVIUM_CN52XX:
922 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
923 		__cpu_name[cpu] = "Cavium Octeon+";
924 platform:
925 		if (cpu == 0)
926 			__elf_platform = "octeon";
927 		break;
928 	default:
929 		printk(KERN_INFO "Unknown Octeon chip!\n");
930 		c->cputype = CPU_UNKNOWN;
931 		break;
932 	}
933 }
934 
935 const char *__cpu_name[NR_CPUS];
936 const char *__elf_platform;
937 
938 __cpuinit void cpu_probe(void)
939 {
940 	struct cpuinfo_mips *c = &current_cpu_data;
941 	unsigned int cpu = smp_processor_id();
942 
943 	c->processor_id	= PRID_IMP_UNKNOWN;
944 	c->fpu_id	= FPIR_IMP_NONE;
945 	c->cputype	= CPU_UNKNOWN;
946 
947 	c->processor_id = read_c0_prid();
948 	switch (c->processor_id & 0xff0000) {
949 	case PRID_COMP_LEGACY:
950 		cpu_probe_legacy(c, cpu);
951 		break;
952 	case PRID_COMP_MIPS:
953 		cpu_probe_mips(c, cpu);
954 		break;
955 	case PRID_COMP_ALCHEMY:
956 		cpu_probe_alchemy(c, cpu);
957 		break;
958 	case PRID_COMP_SIBYTE:
959 		cpu_probe_sibyte(c, cpu);
960 		break;
961 	case PRID_COMP_BROADCOM:
962 		cpu_probe_broadcom(c, cpu);
963 		break;
964 	case PRID_COMP_SANDCRAFT:
965 		cpu_probe_sandcraft(c, cpu);
966 		break;
967 	case PRID_COMP_NXP:
968 		cpu_probe_nxp(c, cpu);
969 		break;
970 	case PRID_COMP_CAVIUM:
971 		cpu_probe_cavium(c, cpu);
972 		break;
973 	}
974 
975 	BUG_ON(!__cpu_name[cpu]);
976 	BUG_ON(c->cputype == CPU_UNKNOWN);
977 
978 	/*
979 	 * Platform code can force the cpu type to optimize code
980 	 * generation. In that case be sure the cpu type is correctly
981 	 * manually setup otherwise it could trigger some nasty bugs.
982 	 */
983 	BUG_ON(current_cpu_type() != c->cputype);
984 
985 	if (c->options & MIPS_CPU_FPU) {
986 		c->fpu_id = cpu_get_fpu_id();
987 
988 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
989 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
990 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
991 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
992 			if (c->fpu_id & MIPS_FPIR_3D)
993 				c->ases |= MIPS_ASE_MIPS3D;
994 		}
995 	}
996 
997 	if (cpu_has_mips_r2)
998 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
999 	else
1000 		c->srsets = 1;
1001 
1002 	cpu_probe_vmbits(c);
1003 }
1004 
1005 __cpuinit void cpu_report(void)
1006 {
1007 	struct cpuinfo_mips *c = &current_cpu_data;
1008 
1009 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1010 	       c->processor_id, cpu_name_string());
1011 	if (c->options & MIPS_CPU_FPU)
1012 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1013 }
1014