xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 
25 /*
26  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
27  * the implementation of the "wait" feature differs between CPU families. This
28  * points to the function that implements CPU specific wait.
29  * The wait instruction stops the pipeline and reduces the power consumption of
30  * the CPU very much.
31  */
32 void (*cpu_wait)(void) = NULL;
33 
34 static void r3081_wait(void)
35 {
36 	unsigned long cfg = read_c0_conf();
37 	write_c0_conf(cfg | R30XX_CONF_HALT);
38 }
39 
40 static void r39xx_wait(void)
41 {
42 	local_irq_disable();
43 	if (!need_resched())
44 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
45 	local_irq_enable();
46 }
47 
48 /*
49  * There is a race when WAIT instruction executed with interrupt
50  * enabled.
51  * But it is implementation-dependent wheter the pipelie restarts when
52  * a non-enabled interrupt is requested.
53  */
54 static void r4k_wait(void)
55 {
56 	__asm__("	.set	mips3			\n"
57 		"	wait				\n"
58 		"	.set	mips0			\n");
59 }
60 
61 /*
62  * This variant is preferable as it allows testing need_resched and going to
63  * sleep depending on the outcome atomically.  Unfortunately the "It is
64  * implementation-dependent whether the pipeline restarts when a non-enabled
65  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
66  * using this version a gamble.
67  */
68 static void r4k_wait_irqoff(void)
69 {
70 	local_irq_disable();
71 	if (!need_resched())
72 		__asm__("	.set	mips3		\n"
73 			"	wait			\n"
74 			"	.set	mips0		\n");
75 	local_irq_enable();
76 }
77 
78 /*
79  * The RM7000 variant has to handle erratum 38.  The workaround is to not
80  * have any pending stores when the WAIT instruction is executed.
81  */
82 static void rm7k_wait_irqoff(void)
83 {
84 	local_irq_disable();
85 	if (!need_resched())
86 		__asm__(
87 		"	.set	push					\n"
88 		"	.set	mips3					\n"
89 		"	.set	noat					\n"
90 		"	mfc0	$1, $12					\n"
91 		"	sync						\n"
92 		"	mtc0	$1, $12		# stalls until W stage	\n"
93 		"	wait						\n"
94 		"	mtc0	$1, $12		# stalls until W stage	\n"
95 		"	.set	pop					\n");
96 	local_irq_enable();
97 }
98 
99 /* The Au1xxx wait is available only if using 32khz counter or
100  * external timer source, but specifically not CP0 Counter. */
101 int allow_au1k_wait;
102 
103 static void au1k_wait(void)
104 {
105 	/* using the wait instruction makes CP0 counter unusable */
106 	__asm__("	.set	mips3			\n"
107 		"	cache	0x14, 0(%0)		\n"
108 		"	cache	0x14, 32(%0)		\n"
109 		"	sync				\n"
110 		"	nop				\n"
111 		"	wait				\n"
112 		"	nop				\n"
113 		"	nop				\n"
114 		"	nop				\n"
115 		"	nop				\n"
116 		"	.set	mips0			\n"
117 		: : "r" (au1k_wait));
118 }
119 
120 static int __initdata nowait = 0;
121 
122 static int __init wait_disable(char *s)
123 {
124 	nowait = 1;
125 
126 	return 1;
127 }
128 
129 __setup("nowait", wait_disable);
130 
131 static inline void check_wait(void)
132 {
133 	struct cpuinfo_mips *c = &current_cpu_data;
134 
135 	if (nowait) {
136 		printk("Wait instruction disabled.\n");
137 		return;
138 	}
139 
140 	switch (c->cputype) {
141 	case CPU_R3081:
142 	case CPU_R3081E:
143 		cpu_wait = r3081_wait;
144 		break;
145 	case CPU_TX3927:
146 		cpu_wait = r39xx_wait;
147 		break;
148 	case CPU_R4200:
149 /*	case CPU_R4300: */
150 	case CPU_R4600:
151 	case CPU_R4640:
152 	case CPU_R4650:
153 	case CPU_R4700:
154 	case CPU_R5000:
155 	case CPU_NEVADA:
156 	case CPU_4KC:
157 	case CPU_4KEC:
158 	case CPU_4KSC:
159 	case CPU_5KC:
160 	case CPU_25KF:
161 	case CPU_PR4450:
162 	case CPU_BCM3302:
163 		cpu_wait = r4k_wait;
164 		break;
165 
166 	case CPU_RM7000:
167 		cpu_wait = rm7k_wait_irqoff;
168 		break;
169 
170 	case CPU_24K:
171 	case CPU_34K:
172 		cpu_wait = r4k_wait;
173 		if (read_c0_config7() & MIPS_CONF7_WII)
174 			cpu_wait = r4k_wait_irqoff;
175 		break;
176 
177 	case CPU_74K:
178 		cpu_wait = r4k_wait;
179 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
180 			cpu_wait = r4k_wait_irqoff;
181 		break;
182 
183 	case CPU_TX49XX:
184 		cpu_wait = r4k_wait_irqoff;
185 		break;
186 	case CPU_AU1000:
187 	case CPU_AU1100:
188 	case CPU_AU1500:
189 	case CPU_AU1550:
190 	case CPU_AU1200:
191 		if (allow_au1k_wait)
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_wait();
243 	check_errata();
244 }
245 
246 /*
247  * Probe whether cpu has config register by trying to play with
248  * alternate cache bit and see whether it matters.
249  * It's used by cpu_probe to distinguish between R3000A and R3081.
250  */
251 static inline int cpu_has_confreg(void)
252 {
253 #ifdef CONFIG_CPU_R3000
254 	extern unsigned long r3k_cache_size(unsigned long);
255 	unsigned long size1, size2;
256 	unsigned long cfg = read_c0_conf();
257 
258 	size1 = r3k_cache_size(ST0_ISC);
259 	write_c0_conf(cfg ^ R30XX_CONF_AC);
260 	size2 = r3k_cache_size(ST0_ISC);
261 	write_c0_conf(cfg);
262 	return size1 != size2;
263 #else
264 	return 0;
265 #endif
266 }
267 
268 /*
269  * Get the FPU Implementation/Revision.
270  */
271 static inline unsigned long cpu_get_fpu_id(void)
272 {
273 	unsigned long tmp, fpu_id;
274 
275 	tmp = read_c0_status();
276 	__enable_fpu();
277 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
278 	write_c0_status(tmp);
279 	return fpu_id;
280 }
281 
282 /*
283  * Check the CPU has an FPU the official way.
284  */
285 static inline int __cpu_has_fpu(void)
286 {
287 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
288 }
289 
290 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
291 		| MIPS_CPU_COUNTER)
292 
293 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
294 {
295 	switch (c->processor_id & 0xff00) {
296 	case PRID_IMP_R2000:
297 		c->cputype = 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 			else
310 				c->cputype = CPU_R3000A;
311 		else
312 			c->cputype = CPU_R3000;
313 		c->isa_level = MIPS_CPU_ISA_I;
314 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
315 		             MIPS_CPU_NOFPUEX;
316 		if (__cpu_has_fpu())
317 			c->options |= MIPS_CPU_FPU;
318 		c->tlbsize = 64;
319 		break;
320 	case PRID_IMP_R4000:
321 		if (read_c0_config() & CONF_SC) {
322 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
323 				c->cputype = CPU_R4400PC;
324 			else
325 				c->cputype = CPU_R4000PC;
326 		} else {
327 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
328 				c->cputype = CPU_R4400SC;
329 			else
330 				c->cputype = CPU_R4000SC;
331 		}
332 
333 		c->isa_level = MIPS_CPU_ISA_III;
334 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
335 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
336 		             MIPS_CPU_LLSC;
337 		c->tlbsize = 48;
338 		break;
339 	case PRID_IMP_VR41XX:
340 		switch (c->processor_id & 0xf0) {
341 		case PRID_REV_VR4111:
342 			c->cputype = CPU_VR4111;
343 			break;
344 		case PRID_REV_VR4121:
345 			c->cputype = CPU_VR4121;
346 			break;
347 		case PRID_REV_VR4122:
348 			if ((c->processor_id & 0xf) < 0x3)
349 				c->cputype = CPU_VR4122;
350 			else
351 				c->cputype = CPU_VR4181A;
352 			break;
353 		case PRID_REV_VR4130:
354 			if ((c->processor_id & 0xf) < 0x4)
355 				c->cputype = CPU_VR4131;
356 			else
357 				c->cputype = CPU_VR4133;
358 			break;
359 		default:
360 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
361 			c->cputype = CPU_VR41XX;
362 			break;
363 		}
364 		c->isa_level = MIPS_CPU_ISA_III;
365 		c->options = R4K_OPTS;
366 		c->tlbsize = 32;
367 		break;
368 	case PRID_IMP_R4300:
369 		c->cputype = CPU_R4300;
370 		c->isa_level = MIPS_CPU_ISA_III;
371 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
372 		             MIPS_CPU_LLSC;
373 		c->tlbsize = 32;
374 		break;
375 	case PRID_IMP_R4600:
376 		c->cputype = CPU_R4600;
377 		c->isa_level = MIPS_CPU_ISA_III;
378 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
379 			     MIPS_CPU_LLSC;
380 		c->tlbsize = 48;
381 		break;
382 	#if 0
383  	case PRID_IMP_R4650:
384 		/*
385 		 * This processor doesn't have an MMU, so it's not
386 		 * "real easy" to run Linux on it. It is left purely
387 		 * for documentation.  Commented out because it shares
388 		 * it's c0_prid id number with the TX3900.
389 		 */
390 		c->cputype = CPU_R4650;
391 	 	c->isa_level = MIPS_CPU_ISA_III;
392 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
393 	        c->tlbsize = 48;
394 		break;
395 	#endif
396 	case PRID_IMP_TX39:
397 		c->isa_level = MIPS_CPU_ISA_I;
398 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
399 
400 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
401 			c->cputype = CPU_TX3927;
402 			c->tlbsize = 64;
403 		} else {
404 			switch (c->processor_id & 0xff) {
405 			case PRID_REV_TX3912:
406 				c->cputype = CPU_TX3912;
407 				c->tlbsize = 32;
408 				break;
409 			case PRID_REV_TX3922:
410 				c->cputype = CPU_TX3922;
411 				c->tlbsize = 64;
412 				break;
413 			default:
414 				c->cputype = CPU_UNKNOWN;
415 				break;
416 			}
417 		}
418 		break;
419 	case PRID_IMP_R4700:
420 		c->cputype = CPU_R4700;
421 		c->isa_level = MIPS_CPU_ISA_III;
422 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
423 		             MIPS_CPU_LLSC;
424 		c->tlbsize = 48;
425 		break;
426 	case PRID_IMP_TX49:
427 		c->cputype = CPU_TX49XX;
428 		c->isa_level = MIPS_CPU_ISA_III;
429 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
430 		if (!(c->processor_id & 0x08))
431 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
432 		c->tlbsize = 48;
433 		break;
434 	case PRID_IMP_R5000:
435 		c->cputype = CPU_R5000;
436 		c->isa_level = MIPS_CPU_ISA_IV;
437 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
438 		             MIPS_CPU_LLSC;
439 		c->tlbsize = 48;
440 		break;
441 	case PRID_IMP_R5432:
442 		c->cputype = CPU_R5432;
443 		c->isa_level = MIPS_CPU_ISA_IV;
444 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
445 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
446 		c->tlbsize = 48;
447 		break;
448 	case PRID_IMP_R5500:
449 		c->cputype = CPU_R5500;
450 		c->isa_level = MIPS_CPU_ISA_IV;
451 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
452 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
453 		c->tlbsize = 48;
454 		break;
455 	case PRID_IMP_NEVADA:
456 		c->cputype = CPU_NEVADA;
457 		c->isa_level = MIPS_CPU_ISA_IV;
458 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
459 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
460 		c->tlbsize = 48;
461 		break;
462 	case PRID_IMP_R6000:
463 		c->cputype = CPU_R6000;
464 		c->isa_level = MIPS_CPU_ISA_II;
465 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
466 		             MIPS_CPU_LLSC;
467 		c->tlbsize = 32;
468 		break;
469 	case PRID_IMP_R6000A:
470 		c->cputype = CPU_R6000A;
471 		c->isa_level = MIPS_CPU_ISA_II;
472 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
473 		             MIPS_CPU_LLSC;
474 		c->tlbsize = 32;
475 		break;
476 	case PRID_IMP_RM7000:
477 		c->cputype = CPU_RM7000;
478 		c->isa_level = MIPS_CPU_ISA_IV;
479 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
480 		             MIPS_CPU_LLSC;
481 		/*
482 		 * Undocumented RM7000:  Bit 29 in the info register of
483 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
484 		 * entries.
485 		 *
486 		 * 29      1 =>    64 entry JTLB
487 		 *         0 =>    48 entry JTLB
488 		 */
489 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
490 		break;
491 	case PRID_IMP_RM9000:
492 		c->cputype = CPU_RM9000;
493 		c->isa_level = MIPS_CPU_ISA_IV;
494 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
495 		             MIPS_CPU_LLSC;
496 		/*
497 		 * Bit 29 in the info register of the RM9000
498 		 * indicates if the TLB has 48 or 64 entries.
499 		 *
500 		 * 29      1 =>    64 entry JTLB
501 		 *         0 =>    48 entry JTLB
502 		 */
503 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
504 		break;
505 	case PRID_IMP_R8000:
506 		c->cputype = CPU_R8000;
507 		c->isa_level = MIPS_CPU_ISA_IV;
508 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
509 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
510 		             MIPS_CPU_LLSC;
511 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
512 		break;
513 	case PRID_IMP_R10000:
514 		c->cputype = CPU_R10000;
515 		c->isa_level = MIPS_CPU_ISA_IV;
516 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
517 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
518 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
519 		             MIPS_CPU_LLSC;
520 		c->tlbsize = 64;
521 		break;
522 	case PRID_IMP_R12000:
523 		c->cputype = CPU_R12000;
524 		c->isa_level = MIPS_CPU_ISA_IV;
525 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
526 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
527 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
528 		             MIPS_CPU_LLSC;
529 		c->tlbsize = 64;
530 		break;
531 	case PRID_IMP_R14000:
532 		c->cputype = CPU_R14000;
533 		c->isa_level = MIPS_CPU_ISA_IV;
534 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
535 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
536 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
537 		             MIPS_CPU_LLSC;
538 		c->tlbsize = 64;
539 		break;
540 	case PRID_IMP_LOONGSON2:
541 		c->cputype = CPU_LOONGSON2;
542 		c->isa_level = MIPS_CPU_ISA_III;
543 		c->options = R4K_OPTS |
544 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
545 			     MIPS_CPU_32FPR;
546 		c->tlbsize = 64;
547 		break;
548 	}
549 }
550 
551 static char unknown_isa[] __initdata = KERN_ERR \
552 	"Unsupported ISA type, c0.config0: %d.";
553 
554 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
555 {
556 	unsigned int config0;
557 	int isa;
558 
559 	config0 = read_c0_config();
560 
561 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
562 		c->options |= MIPS_CPU_TLB;
563 	isa = (config0 & MIPS_CONF_AT) >> 13;
564 	switch (isa) {
565 	case 0:
566 		switch ((config0 & MIPS_CONF_AR) >> 10) {
567 		case 0:
568 			c->isa_level = MIPS_CPU_ISA_M32R1;
569 			break;
570 		case 1:
571 			c->isa_level = MIPS_CPU_ISA_M32R2;
572 			break;
573 		default:
574 			goto unknown;
575 		}
576 		break;
577 	case 2:
578 		switch ((config0 & MIPS_CONF_AR) >> 10) {
579 		case 0:
580 			c->isa_level = MIPS_CPU_ISA_M64R1;
581 			break;
582 		case 1:
583 			c->isa_level = MIPS_CPU_ISA_M64R2;
584 			break;
585 		default:
586 			goto unknown;
587 		}
588 		break;
589 	default:
590 		goto unknown;
591 	}
592 
593 	return config0 & MIPS_CONF_M;
594 
595 unknown:
596 	panic(unknown_isa, config0);
597 }
598 
599 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
600 {
601 	unsigned int config1;
602 
603 	config1 = read_c0_config1();
604 
605 	if (config1 & MIPS_CONF1_MD)
606 		c->ases |= MIPS_ASE_MDMX;
607 	if (config1 & MIPS_CONF1_WR)
608 		c->options |= MIPS_CPU_WATCH;
609 	if (config1 & MIPS_CONF1_CA)
610 		c->ases |= MIPS_ASE_MIPS16;
611 	if (config1 & MIPS_CONF1_EP)
612 		c->options |= MIPS_CPU_EJTAG;
613 	if (config1 & MIPS_CONF1_FP) {
614 		c->options |= MIPS_CPU_FPU;
615 		c->options |= MIPS_CPU_32FPR;
616 	}
617 	if (cpu_has_tlb)
618 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
619 
620 	return config1 & MIPS_CONF_M;
621 }
622 
623 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
624 {
625 	unsigned int config2;
626 
627 	config2 = read_c0_config2();
628 
629 	if (config2 & MIPS_CONF2_SL)
630 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
631 
632 	return config2 & MIPS_CONF_M;
633 }
634 
635 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
636 {
637 	unsigned int config3;
638 
639 	config3 = read_c0_config3();
640 
641 	if (config3 & MIPS_CONF3_SM)
642 		c->ases |= MIPS_ASE_SMARTMIPS;
643 	if (config3 & MIPS_CONF3_DSP)
644 		c->ases |= MIPS_ASE_DSP;
645 	if (config3 & MIPS_CONF3_VINT)
646 		c->options |= MIPS_CPU_VINT;
647 	if (config3 & MIPS_CONF3_VEIC)
648 		c->options |= MIPS_CPU_VEIC;
649 	if (config3 & MIPS_CONF3_MT)
650 	        c->ases |= MIPS_ASE_MIPSMT;
651 	if (config3 & MIPS_CONF3_ULRI)
652 		c->options |= MIPS_CPU_ULRI;
653 
654 	return config3 & MIPS_CONF_M;
655 }
656 
657 static void __init decode_configs(struct cpuinfo_mips *c)
658 {
659 	/* MIPS32 or MIPS64 compliant CPU.  */
660 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
661 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
662 
663 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
664 
665 	/* Read Config registers.  */
666 	if (!decode_config0(c))
667 		return;			/* actually worth a panic() */
668 	if (!decode_config1(c))
669 		return;
670 	if (!decode_config2(c))
671 		return;
672 	if (!decode_config3(c))
673 		return;
674 }
675 
676 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
677 {
678 	decode_configs(c);
679 	switch (c->processor_id & 0xff00) {
680 	case PRID_IMP_4KC:
681 		c->cputype = CPU_4KC;
682 		break;
683 	case PRID_IMP_4KEC:
684 		c->cputype = CPU_4KEC;
685 		break;
686 	case PRID_IMP_4KECR2:
687 		c->cputype = CPU_4KEC;
688 		break;
689 	case PRID_IMP_4KSC:
690 	case PRID_IMP_4KSD:
691 		c->cputype = CPU_4KSC;
692 		break;
693 	case PRID_IMP_5KC:
694 		c->cputype = CPU_5KC;
695 		break;
696 	case PRID_IMP_20KC:
697 		c->cputype = CPU_20KC;
698 		break;
699 	case PRID_IMP_24K:
700 	case PRID_IMP_24KE:
701 		c->cputype = CPU_24K;
702 		break;
703 	case PRID_IMP_25KF:
704 		c->cputype = CPU_25KF;
705 		break;
706 	case PRID_IMP_34K:
707 		c->cputype = CPU_34K;
708 		break;
709 	case PRID_IMP_74K:
710 		c->cputype = CPU_74K;
711 		break;
712 	}
713 }
714 
715 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
716 {
717 	decode_configs(c);
718 	switch (c->processor_id & 0xff00) {
719 	case PRID_IMP_AU1_REV1:
720 	case PRID_IMP_AU1_REV2:
721 		switch ((c->processor_id >> 24) & 0xff) {
722 		case 0:
723 			c->cputype = CPU_AU1000;
724 			break;
725 		case 1:
726 			c->cputype = CPU_AU1500;
727 			break;
728 		case 2:
729 			c->cputype = CPU_AU1100;
730 			break;
731 		case 3:
732 			c->cputype = CPU_AU1550;
733 			break;
734 		case 4:
735 			c->cputype = CPU_AU1200;
736 			break;
737 		default:
738 			panic("Unknown Au Core!");
739 			break;
740 		}
741 		break;
742 	}
743 }
744 
745 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
746 {
747 	decode_configs(c);
748 
749 	switch (c->processor_id & 0xff00) {
750 	case PRID_IMP_SB1:
751 		c->cputype = CPU_SB1;
752 		/* FPU in pass1 is known to have issues. */
753 		if ((c->processor_id & 0xff) < 0x02)
754 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
755 		break;
756 	case PRID_IMP_SB1A:
757 		c->cputype = CPU_SB1A;
758 		break;
759 	}
760 }
761 
762 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
763 {
764 	decode_configs(c);
765 	switch (c->processor_id & 0xff00) {
766 	case PRID_IMP_SR71000:
767 		c->cputype = CPU_SR71000;
768 		c->scache.ways = 8;
769 		c->tlbsize = 64;
770 		break;
771 	}
772 }
773 
774 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
775 {
776 	decode_configs(c);
777 	switch (c->processor_id & 0xff00) {
778 	case PRID_IMP_PR4450:
779 		c->cputype = CPU_PR4450;
780 		c->isa_level = MIPS_CPU_ISA_M32R1;
781 		break;
782 	default:
783 		panic("Unknown Philips Core!"); /* REVISIT: die? */
784 		break;
785 	}
786 }
787 
788 
789 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c)
790 {
791 	decode_configs(c);
792 	switch (c->processor_id & 0xff00) {
793 	case PRID_IMP_BCM3302:
794 		c->cputype = CPU_BCM3302;
795 		break;
796 	case PRID_IMP_BCM4710:
797 		c->cputype = CPU_BCM4710;
798 		break;
799 	default:
800 		c->cputype = CPU_UNKNOWN;
801 		break;
802 	}
803 }
804 
805 const char *__cpu_name[NR_CPUS];
806 
807 /*
808  * Name a CPU
809  */
810 static __init const char *cpu_to_name(struct cpuinfo_mips *c)
811 {
812 	const char *name = NULL;
813 
814 	switch (c->cputype) {
815 	case CPU_UNKNOWN:	name = "unknown"; break;
816 	case CPU_R2000:		name = "R2000"; break;
817 	case CPU_R3000:		name = "R3000"; break;
818 	case CPU_R3000A:	name = "R3000A"; break;
819 	case CPU_R3041:		name = "R3041"; break;
820 	case CPU_R3051:		name = "R3051"; break;
821 	case CPU_R3052:		name = "R3052"; break;
822 	case CPU_R3081:		name = "R3081"; break;
823 	case CPU_R3081E:	name = "R3081E"; break;
824 	case CPU_R4000PC:	name = "R4000PC"; break;
825 	case CPU_R4000SC:	name = "R4000SC"; break;
826 	case CPU_R4000MC:	name = "R4000MC"; break;
827 	case CPU_R4200:		name = "R4200"; break;
828 	case CPU_R4400PC:	name = "R4400PC"; break;
829 	case CPU_R4400SC:	name = "R4400SC"; break;
830 	case CPU_R4400MC:	name = "R4400MC"; break;
831 	case CPU_R4600:		name = "R4600"; break;
832 	case CPU_R6000:		name = "R6000"; break;
833 	case CPU_R6000A:	name = "R6000A"; break;
834 	case CPU_R8000:		name = "R8000"; break;
835 	case CPU_R10000:	name = "R10000"; break;
836 	case CPU_R12000:	name = "R12000"; break;
837 	case CPU_R14000:	name = "R14000"; break;
838 	case CPU_R4300:		name = "R4300"; break;
839 	case CPU_R4650:		name = "R4650"; break;
840 	case CPU_R4700:		name = "R4700"; break;
841 	case CPU_R5000:		name = "R5000"; break;
842 	case CPU_R5000A:	name = "R5000A"; break;
843 	case CPU_R4640:		name = "R4640"; break;
844 	case CPU_NEVADA:	name = "Nevada"; break;
845 	case CPU_RM7000:	name = "RM7000"; break;
846 	case CPU_RM9000:	name = "RM9000"; break;
847 	case CPU_R5432:		name = "R5432"; break;
848 	case CPU_4KC:		name = "MIPS 4Kc"; break;
849 	case CPU_5KC:		name = "MIPS 5Kc"; break;
850 	case CPU_R4310:		name = "R4310"; break;
851 	case CPU_SB1:		name = "SiByte SB1"; break;
852 	case CPU_SB1A:		name = "SiByte SB1A"; break;
853 	case CPU_TX3912:	name = "TX3912"; break;
854 	case CPU_TX3922:	name = "TX3922"; break;
855 	case CPU_TX3927:	name = "TX3927"; break;
856 	case CPU_AU1000:	name = "Au1000"; break;
857 	case CPU_AU1500:	name = "Au1500"; break;
858 	case CPU_AU1100:	name = "Au1100"; break;
859 	case CPU_AU1550:	name = "Au1550"; break;
860 	case CPU_AU1200:	name = "Au1200"; break;
861 	case CPU_4KEC:		name = "MIPS 4KEc"; break;
862 	case CPU_4KSC:		name = "MIPS 4KSc"; break;
863 	case CPU_VR41XX:	name = "NEC Vr41xx"; break;
864 	case CPU_R5500:		name = "R5500"; break;
865 	case CPU_TX49XX:	name = "TX49xx"; break;
866 	case CPU_20KC:		name = "MIPS 20Kc"; break;
867 	case CPU_24K:		name = "MIPS 24K"; break;
868 	case CPU_25KF:		name = "MIPS 25Kf"; break;
869 	case CPU_34K:		name = "MIPS 34K"; break;
870 	case CPU_74K:		name = "MIPS 74K"; break;
871 	case CPU_VR4111:	name = "NEC VR4111"; break;
872 	case CPU_VR4121:	name = "NEC VR4121"; break;
873 	case CPU_VR4122:	name = "NEC VR4122"; break;
874 	case CPU_VR4131:	name = "NEC VR4131"; break;
875 	case CPU_VR4133:	name = "NEC VR4133"; break;
876 	case CPU_VR4181:	name = "NEC VR4181"; break;
877 	case CPU_VR4181A:	name = "NEC VR4181A"; break;
878 	case CPU_SR71000:	name = "Sandcraft SR71000"; break;
879 	case CPU_BCM3302:	name = "Broadcom BCM3302"; break;
880 	case CPU_BCM4710:	name = "Broadcom BCM4710"; break;
881 	case CPU_PR4450:	name = "Philips PR4450"; break;
882 	case CPU_LOONGSON2:	name = "ICT Loongson-2"; break;
883 	default:
884 		BUG();
885 	}
886 
887 	return name;
888 }
889 
890 __init void cpu_probe(void)
891 {
892 	struct cpuinfo_mips *c = &current_cpu_data;
893 	unsigned int cpu = smp_processor_id();
894 
895 	c->processor_id	= PRID_IMP_UNKNOWN;
896 	c->fpu_id	= FPIR_IMP_NONE;
897 	c->cputype	= CPU_UNKNOWN;
898 
899 	c->processor_id = read_c0_prid();
900 	switch (c->processor_id & 0xff0000) {
901 	case PRID_COMP_LEGACY:
902 		cpu_probe_legacy(c);
903 		break;
904 	case PRID_COMP_MIPS:
905 		cpu_probe_mips(c);
906 		break;
907 	case PRID_COMP_ALCHEMY:
908 		cpu_probe_alchemy(c);
909 		break;
910 	case PRID_COMP_SIBYTE:
911 		cpu_probe_sibyte(c);
912 		break;
913 	case PRID_COMP_BROADCOM:
914 		cpu_probe_broadcom(c);
915 		break;
916 	case PRID_COMP_SANDCRAFT:
917 		cpu_probe_sandcraft(c);
918 		break;
919  	case PRID_COMP_PHILIPS:
920 		cpu_probe_philips(c);
921 		break;
922 	default:
923 		c->cputype = CPU_UNKNOWN;
924 	}
925 
926 	/*
927 	 * Platform code can force the cpu type to optimize code
928 	 * generation. In that case be sure the cpu type is correctly
929 	 * manually setup otherwise it could trigger some nasty bugs.
930 	 */
931 	BUG_ON(current_cpu_type() != c->cputype);
932 
933 	if (c->options & MIPS_CPU_FPU) {
934 		c->fpu_id = cpu_get_fpu_id();
935 
936 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
937 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
938 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
939 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
940 			if (c->fpu_id & MIPS_FPIR_3D)
941 				c->ases |= MIPS_ASE_MIPS3D;
942 		}
943 	}
944 
945 	__cpu_name[cpu] = cpu_to_name(c);
946 }
947 
948 __init void cpu_report(void)
949 {
950 	struct cpuinfo_mips *c = &current_cpu_data;
951 
952 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
953 	       c->processor_id, cpu_name_string());
954 	if (c->options & MIPS_CPU_FPU)
955 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
956 }
957