xref: /linux/arch/mips/kernel/cpu-probe.c (revision b0148a98ec5151fec82064d95f11eb9efbc628ea)
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/cpu.h>
20 #include <asm/fpu.h>
21 #include <asm/mipsregs.h>
22 #include <asm/system.h>
23 
24 /*
25  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
26  * the implementation of the "wait" feature differs between CPU families. This
27  * points to the function that implements CPU specific wait.
28  * The wait instruction stops the pipeline and reduces the power consumption of
29  * the CPU very much.
30  */
31 void (*cpu_wait)(void) = NULL;
32 
33 static void r3081_wait(void)
34 {
35 	unsigned long cfg = read_c0_conf();
36 	write_c0_conf(cfg | R30XX_CONF_HALT);
37 }
38 
39 static void r39xx_wait(void)
40 {
41 	local_irq_disable();
42 	if (!need_resched())
43 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
44 	local_irq_enable();
45 }
46 
47 /*
48  * There is a race when WAIT instruction executed with interrupt
49  * enabled.
50  * But it is implementation-dependent wheter the pipelie restarts when
51  * a non-enabled interrupt is requested.
52  */
53 static void r4k_wait(void)
54 {
55 	__asm__("	.set	mips3			\n"
56 		"	wait				\n"
57 		"	.set	mips0			\n");
58 }
59 
60 /*
61  * This variant is preferable as it allows testing need_resched and going to
62  * sleep depending on the outcome atomically.  Unfortunately the "It is
63  * implementation-dependent whether the pipeline restarts when a non-enabled
64  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
65  * using this version a gamble.
66  */
67 static void r4k_wait_irqoff(void)
68 {
69 	local_irq_disable();
70 	if (!need_resched())
71 		__asm__("	.set	mips3		\n"
72 			"	wait			\n"
73 			"	.set	mips0		\n");
74 	local_irq_enable();
75 }
76 
77 /* The Au1xxx wait is available only if using 32khz counter or
78  * external timer source, but specifically not CP0 Counter. */
79 int allow_au1k_wait;
80 
81 static void au1k_wait(void)
82 {
83 	/* using the wait instruction makes CP0 counter unusable */
84 	__asm__("	.set	mips3			\n"
85 		"	cache	0x14, 0(%0)		\n"
86 		"	cache	0x14, 32(%0)		\n"
87 		"	sync				\n"
88 		"	nop				\n"
89 		"	wait				\n"
90 		"	nop				\n"
91 		"	nop				\n"
92 		"	nop				\n"
93 		"	nop				\n"
94 		"	.set	mips0			\n"
95 		: : "r" (au1k_wait));
96 }
97 
98 static int __initdata nowait = 0;
99 
100 int __init wait_disable(char *s)
101 {
102 	nowait = 1;
103 
104 	return 1;
105 }
106 
107 __setup("nowait", wait_disable);
108 
109 static inline void check_wait(void)
110 {
111 	struct cpuinfo_mips *c = &current_cpu_data;
112 
113 	if (nowait) {
114 		printk("Wait instruction disabled.\n");
115 		return;
116 	}
117 
118 	switch (c->cputype) {
119 	case CPU_R3081:
120 	case CPU_R3081E:
121 		cpu_wait = r3081_wait;
122 		break;
123 	case CPU_TX3927:
124 		cpu_wait = r39xx_wait;
125 		break;
126 	case CPU_R4200:
127 /*	case CPU_R4300: */
128 	case CPU_R4600:
129 	case CPU_R4640:
130 	case CPU_R4650:
131 	case CPU_R4700:
132 	case CPU_R5000:
133 	case CPU_NEVADA:
134 	case CPU_RM7000:
135 	case CPU_4KC:
136 	case CPU_4KEC:
137 	case CPU_4KSC:
138 	case CPU_5KC:
139 /*	case CPU_20KC:*/
140 	case CPU_24K:
141 	case CPU_25KF:
142 	case CPU_34K:
143 	case CPU_74K:
144  	case CPU_PR4450:
145 		cpu_wait = r4k_wait;
146 		break;
147 	case CPU_TX49XX:
148 		cpu_wait = r4k_wait_irqoff;
149 		break;
150 	case CPU_AU1000:
151 	case CPU_AU1100:
152 	case CPU_AU1500:
153 	case CPU_AU1550:
154 	case CPU_AU1200:
155 		if (allow_au1k_wait)
156 			cpu_wait = au1k_wait;
157 		break;
158 	case CPU_RM9000:
159 		if ((c->processor_id & 0x00ff) >= 0x40)
160 			cpu_wait = r4k_wait;
161 		break;
162 	default:
163 		break;
164 	}
165 }
166 
167 void __init check_bugs32(void)
168 {
169 	check_wait();
170 }
171 
172 /*
173  * Probe whether cpu has config register by trying to play with
174  * alternate cache bit and see whether it matters.
175  * It's used by cpu_probe to distinguish between R3000A and R3081.
176  */
177 static inline int cpu_has_confreg(void)
178 {
179 #ifdef CONFIG_CPU_R3000
180 	extern unsigned long r3k_cache_size(unsigned long);
181 	unsigned long size1, size2;
182 	unsigned long cfg = read_c0_conf();
183 
184 	size1 = r3k_cache_size(ST0_ISC);
185 	write_c0_conf(cfg ^ R30XX_CONF_AC);
186 	size2 = r3k_cache_size(ST0_ISC);
187 	write_c0_conf(cfg);
188 	return size1 != size2;
189 #else
190 	return 0;
191 #endif
192 }
193 
194 /*
195  * Get the FPU Implementation/Revision.
196  */
197 static inline unsigned long cpu_get_fpu_id(void)
198 {
199 	unsigned long tmp, fpu_id;
200 
201 	tmp = read_c0_status();
202 	__enable_fpu();
203 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
204 	write_c0_status(tmp);
205 	return fpu_id;
206 }
207 
208 /*
209  * Check the CPU has an FPU the official way.
210  */
211 static inline int __cpu_has_fpu(void)
212 {
213 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
214 }
215 
216 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
217 		| MIPS_CPU_COUNTER)
218 
219 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
220 {
221 	switch (c->processor_id & 0xff00) {
222 	case PRID_IMP_R2000:
223 		c->cputype = CPU_R2000;
224 		c->isa_level = MIPS_CPU_ISA_I;
225 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
226 		             MIPS_CPU_NOFPUEX;
227 		if (__cpu_has_fpu())
228 			c->options |= MIPS_CPU_FPU;
229 		c->tlbsize = 64;
230 		break;
231 	case PRID_IMP_R3000:
232 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
233 			if (cpu_has_confreg())
234 				c->cputype = CPU_R3081E;
235 			else
236 				c->cputype = CPU_R3000A;
237 		else
238 			c->cputype = CPU_R3000;
239 		c->isa_level = MIPS_CPU_ISA_I;
240 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
241 		             MIPS_CPU_NOFPUEX;
242 		if (__cpu_has_fpu())
243 			c->options |= MIPS_CPU_FPU;
244 		c->tlbsize = 64;
245 		break;
246 	case PRID_IMP_R4000:
247 		if (read_c0_config() & CONF_SC) {
248 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
249 				c->cputype = CPU_R4400PC;
250 			else
251 				c->cputype = CPU_R4000PC;
252 		} else {
253 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
254 				c->cputype = CPU_R4400SC;
255 			else
256 				c->cputype = CPU_R4000SC;
257 		}
258 
259 		c->isa_level = MIPS_CPU_ISA_III;
260 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
261 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
262 		             MIPS_CPU_LLSC;
263 		c->tlbsize = 48;
264 		break;
265 	case PRID_IMP_VR41XX:
266 		switch (c->processor_id & 0xf0) {
267 		case PRID_REV_VR4111:
268 			c->cputype = CPU_VR4111;
269 			break;
270 		case PRID_REV_VR4121:
271 			c->cputype = CPU_VR4121;
272 			break;
273 		case PRID_REV_VR4122:
274 			if ((c->processor_id & 0xf) < 0x3)
275 				c->cputype = CPU_VR4122;
276 			else
277 				c->cputype = CPU_VR4181A;
278 			break;
279 		case PRID_REV_VR4130:
280 			if ((c->processor_id & 0xf) < 0x4)
281 				c->cputype = CPU_VR4131;
282 			else
283 				c->cputype = CPU_VR4133;
284 			break;
285 		default:
286 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
287 			c->cputype = CPU_VR41XX;
288 			break;
289 		}
290 		c->isa_level = MIPS_CPU_ISA_III;
291 		c->options = R4K_OPTS;
292 		c->tlbsize = 32;
293 		break;
294 	case PRID_IMP_R4300:
295 		c->cputype = CPU_R4300;
296 		c->isa_level = MIPS_CPU_ISA_III;
297 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
298 		             MIPS_CPU_LLSC;
299 		c->tlbsize = 32;
300 		break;
301 	case PRID_IMP_R4600:
302 		c->cputype = CPU_R4600;
303 		c->isa_level = MIPS_CPU_ISA_III;
304 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
305 			     MIPS_CPU_LLSC;
306 		c->tlbsize = 48;
307 		break;
308 	#if 0
309  	case PRID_IMP_R4650:
310 		/*
311 		 * This processor doesn't have an MMU, so it's not
312 		 * "real easy" to run Linux on it. It is left purely
313 		 * for documentation.  Commented out because it shares
314 		 * it's c0_prid id number with the TX3900.
315 		 */
316 		c->cputype = CPU_R4650;
317 	 	c->isa_level = MIPS_CPU_ISA_III;
318 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
319 	        c->tlbsize = 48;
320 		break;
321 	#endif
322 	case PRID_IMP_TX39:
323 		c->isa_level = MIPS_CPU_ISA_I;
324 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
325 
326 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
327 			c->cputype = CPU_TX3927;
328 			c->tlbsize = 64;
329 		} else {
330 			switch (c->processor_id & 0xff) {
331 			case PRID_REV_TX3912:
332 				c->cputype = CPU_TX3912;
333 				c->tlbsize = 32;
334 				break;
335 			case PRID_REV_TX3922:
336 				c->cputype = CPU_TX3922;
337 				c->tlbsize = 64;
338 				break;
339 			default:
340 				c->cputype = CPU_UNKNOWN;
341 				break;
342 			}
343 		}
344 		break;
345 	case PRID_IMP_R4700:
346 		c->cputype = CPU_R4700;
347 		c->isa_level = MIPS_CPU_ISA_III;
348 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
349 		             MIPS_CPU_LLSC;
350 		c->tlbsize = 48;
351 		break;
352 	case PRID_IMP_TX49:
353 		c->cputype = CPU_TX49XX;
354 		c->isa_level = MIPS_CPU_ISA_III;
355 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
356 		if (!(c->processor_id & 0x08))
357 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
358 		c->tlbsize = 48;
359 		break;
360 	case PRID_IMP_R5000:
361 		c->cputype = CPU_R5000;
362 		c->isa_level = MIPS_CPU_ISA_IV;
363 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
364 		             MIPS_CPU_LLSC;
365 		c->tlbsize = 48;
366 		break;
367 	case PRID_IMP_R5432:
368 		c->cputype = CPU_R5432;
369 		c->isa_level = MIPS_CPU_ISA_IV;
370 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
371 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
372 		c->tlbsize = 48;
373 		break;
374 	case PRID_IMP_R5500:
375 		c->cputype = CPU_R5500;
376 		c->isa_level = MIPS_CPU_ISA_IV;
377 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
378 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
379 		c->tlbsize = 48;
380 		break;
381 	case PRID_IMP_NEVADA:
382 		c->cputype = CPU_NEVADA;
383 		c->isa_level = MIPS_CPU_ISA_IV;
384 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
385 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
386 		c->tlbsize = 48;
387 		break;
388 	case PRID_IMP_R6000:
389 		c->cputype = CPU_R6000;
390 		c->isa_level = MIPS_CPU_ISA_II;
391 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
392 		             MIPS_CPU_LLSC;
393 		c->tlbsize = 32;
394 		break;
395 	case PRID_IMP_R6000A:
396 		c->cputype = CPU_R6000A;
397 		c->isa_level = MIPS_CPU_ISA_II;
398 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
399 		             MIPS_CPU_LLSC;
400 		c->tlbsize = 32;
401 		break;
402 	case PRID_IMP_RM7000:
403 		c->cputype = CPU_RM7000;
404 		c->isa_level = MIPS_CPU_ISA_IV;
405 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
406 		             MIPS_CPU_LLSC;
407 		/*
408 		 * Undocumented RM7000:  Bit 29 in the info register of
409 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
410 		 * entries.
411 		 *
412 		 * 29      1 =>    64 entry JTLB
413 		 *         0 =>    48 entry JTLB
414 		 */
415 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
416 		break;
417 	case PRID_IMP_RM9000:
418 		c->cputype = CPU_RM9000;
419 		c->isa_level = MIPS_CPU_ISA_IV;
420 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
421 		             MIPS_CPU_LLSC;
422 		/*
423 		 * Bit 29 in the info register of the RM9000
424 		 * indicates if the TLB has 48 or 64 entries.
425 		 *
426 		 * 29      1 =>    64 entry JTLB
427 		 *         0 =>    48 entry JTLB
428 		 */
429 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
430 		break;
431 	case PRID_IMP_R8000:
432 		c->cputype = CPU_R8000;
433 		c->isa_level = MIPS_CPU_ISA_IV;
434 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
435 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
436 		             MIPS_CPU_LLSC;
437 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
438 		break;
439 	case PRID_IMP_R10000:
440 		c->cputype = CPU_R10000;
441 		c->isa_level = MIPS_CPU_ISA_IV;
442 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
443 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
444 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
445 		             MIPS_CPU_LLSC;
446 		c->tlbsize = 64;
447 		break;
448 	case PRID_IMP_R12000:
449 		c->cputype = CPU_R12000;
450 		c->isa_level = MIPS_CPU_ISA_IV;
451 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
452 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
453 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
454 		             MIPS_CPU_LLSC;
455 		c->tlbsize = 64;
456 		break;
457 	case PRID_IMP_R14000:
458 		c->cputype = CPU_R14000;
459 		c->isa_level = MIPS_CPU_ISA_IV;
460 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
461 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
462 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
463 		             MIPS_CPU_LLSC;
464 		c->tlbsize = 64;
465 		break;
466 	}
467 }
468 
469 static char unknown_isa[] __initdata = KERN_ERR \
470 	"Unsupported ISA type, c0.config0: %d.";
471 
472 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
473 {
474 	unsigned int config0;
475 	int isa;
476 
477 	config0 = read_c0_config();
478 
479 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
480 		c->options |= MIPS_CPU_TLB;
481 	isa = (config0 & MIPS_CONF_AT) >> 13;
482 	switch (isa) {
483 	case 0:
484 		switch ((config0 & MIPS_CONF_AR) >> 10) {
485 		case 0:
486 			c->isa_level = MIPS_CPU_ISA_M32R1;
487 			break;
488 		case 1:
489 			c->isa_level = MIPS_CPU_ISA_M32R2;
490 			break;
491 		default:
492 			goto unknown;
493 		}
494 		break;
495 	case 2:
496 		switch ((config0 & MIPS_CONF_AR) >> 10) {
497 		case 0:
498 			c->isa_level = MIPS_CPU_ISA_M64R1;
499 			break;
500 		case 1:
501 			c->isa_level = MIPS_CPU_ISA_M64R2;
502 			break;
503 		default:
504 			goto unknown;
505 		}
506 		break;
507 	default:
508 		goto unknown;
509 	}
510 
511 	return config0 & MIPS_CONF_M;
512 
513 unknown:
514 	panic(unknown_isa, config0);
515 }
516 
517 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
518 {
519 	unsigned int config1;
520 
521 	config1 = read_c0_config1();
522 
523 	if (config1 & MIPS_CONF1_MD)
524 		c->ases |= MIPS_ASE_MDMX;
525 	if (config1 & MIPS_CONF1_WR)
526 		c->options |= MIPS_CPU_WATCH;
527 	if (config1 & MIPS_CONF1_CA)
528 		c->ases |= MIPS_ASE_MIPS16;
529 	if (config1 & MIPS_CONF1_EP)
530 		c->options |= MIPS_CPU_EJTAG;
531 	if (config1 & MIPS_CONF1_FP) {
532 		c->options |= MIPS_CPU_FPU;
533 		c->options |= MIPS_CPU_32FPR;
534 	}
535 	if (cpu_has_tlb)
536 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
537 
538 	return config1 & MIPS_CONF_M;
539 }
540 
541 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
542 {
543 	unsigned int config2;
544 
545 	config2 = read_c0_config2();
546 
547 	if (config2 & MIPS_CONF2_SL)
548 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
549 
550 	return config2 & MIPS_CONF_M;
551 }
552 
553 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
554 {
555 	unsigned int config3;
556 
557 	config3 = read_c0_config3();
558 
559 	if (config3 & MIPS_CONF3_SM)
560 		c->ases |= MIPS_ASE_SMARTMIPS;
561 	if (config3 & MIPS_CONF3_DSP)
562 		c->ases |= MIPS_ASE_DSP;
563 	if (config3 & MIPS_CONF3_VINT)
564 		c->options |= MIPS_CPU_VINT;
565 	if (config3 & MIPS_CONF3_VEIC)
566 		c->options |= MIPS_CPU_VEIC;
567 	if (config3 & MIPS_CONF3_MT)
568 	        c->ases |= MIPS_ASE_MIPSMT;
569 
570 	return config3 & MIPS_CONF_M;
571 }
572 
573 static void __init decode_configs(struct cpuinfo_mips *c)
574 {
575 	/* MIPS32 or MIPS64 compliant CPU.  */
576 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
577 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
578 
579 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
580 
581 	/* Read Config registers.  */
582 	if (!decode_config0(c))
583 		return;			/* actually worth a panic() */
584 	if (!decode_config1(c))
585 		return;
586 	if (!decode_config2(c))
587 		return;
588 	if (!decode_config3(c))
589 		return;
590 }
591 
592 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
593 {
594 	decode_configs(c);
595 	switch (c->processor_id & 0xff00) {
596 	case PRID_IMP_4KC:
597 		c->cputype = CPU_4KC;
598 		break;
599 	case PRID_IMP_4KEC:
600 		c->cputype = CPU_4KEC;
601 		break;
602 	case PRID_IMP_4KECR2:
603 		c->cputype = CPU_4KEC;
604 		break;
605 	case PRID_IMP_4KSC:
606 	case PRID_IMP_4KSD:
607 		c->cputype = CPU_4KSC;
608 		break;
609 	case PRID_IMP_5KC:
610 		c->cputype = CPU_5KC;
611 		break;
612 	case PRID_IMP_20KC:
613 		c->cputype = CPU_20KC;
614 		break;
615 	case PRID_IMP_24K:
616 	case PRID_IMP_24KE:
617 		c->cputype = CPU_24K;
618 		break;
619 	case PRID_IMP_25KF:
620 		c->cputype = CPU_25KF;
621 		break;
622 	case PRID_IMP_34K:
623 		c->cputype = CPU_34K;
624 		break;
625 	case PRID_IMP_74K:
626 		c->cputype = CPU_74K;
627 		break;
628 	}
629 }
630 
631 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
632 {
633 	decode_configs(c);
634 	switch (c->processor_id & 0xff00) {
635 	case PRID_IMP_AU1_REV1:
636 	case PRID_IMP_AU1_REV2:
637 		switch ((c->processor_id >> 24) & 0xff) {
638 		case 0:
639 			c->cputype = CPU_AU1000;
640 			break;
641 		case 1:
642 			c->cputype = CPU_AU1500;
643 			break;
644 		case 2:
645 			c->cputype = CPU_AU1100;
646 			break;
647 		case 3:
648 			c->cputype = CPU_AU1550;
649 			break;
650 		case 4:
651 			c->cputype = CPU_AU1200;
652 			break;
653 		default:
654 			panic("Unknown Au Core!");
655 			break;
656 		}
657 		break;
658 	}
659 }
660 
661 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
662 {
663 	decode_configs(c);
664 
665 	/*
666 	 * For historical reasons the SB1 comes with it's own variant of
667 	 * cache code which eventually will be folded into c-r4k.c.  Until
668 	 * then we pretend it's got it's own cache architecture.
669 	 */
670 	c->options &= ~MIPS_CPU_4K_CACHE;
671 	c->options |= MIPS_CPU_SB1_CACHE;
672 
673 	switch (c->processor_id & 0xff00) {
674 	case PRID_IMP_SB1:
675 		c->cputype = CPU_SB1;
676 		/* FPU in pass1 is known to have issues. */
677 		if ((c->processor_id & 0xff) < 0x02)
678 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
679 		break;
680 	case PRID_IMP_SB1A:
681 		c->cputype = CPU_SB1A;
682 		break;
683 	}
684 }
685 
686 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
687 {
688 	decode_configs(c);
689 	switch (c->processor_id & 0xff00) {
690 	case PRID_IMP_SR71000:
691 		c->cputype = CPU_SR71000;
692 		c->scache.ways = 8;
693 		c->tlbsize = 64;
694 		break;
695 	}
696 }
697 
698 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
699 {
700 	decode_configs(c);
701 	switch (c->processor_id & 0xff00) {
702 	case PRID_IMP_PR4450:
703 		c->cputype = CPU_PR4450;
704 		c->isa_level = MIPS_CPU_ISA_M32R1;
705 		break;
706 	default:
707 		panic("Unknown Philips Core!"); /* REVISIT: die? */
708 		break;
709 	}
710 }
711 
712 
713 __init void cpu_probe(void)
714 {
715 	struct cpuinfo_mips *c = &current_cpu_data;
716 
717 	c->processor_id	= PRID_IMP_UNKNOWN;
718 	c->fpu_id	= FPIR_IMP_NONE;
719 	c->cputype	= CPU_UNKNOWN;
720 
721 	c->processor_id = read_c0_prid();
722 	switch (c->processor_id & 0xff0000) {
723 	case PRID_COMP_LEGACY:
724 		cpu_probe_legacy(c);
725 		break;
726 	case PRID_COMP_MIPS:
727 		cpu_probe_mips(c);
728 		break;
729 	case PRID_COMP_ALCHEMY:
730 		cpu_probe_alchemy(c);
731 		break;
732 	case PRID_COMP_SIBYTE:
733 		cpu_probe_sibyte(c);
734 		break;
735 	case PRID_COMP_SANDCRAFT:
736 		cpu_probe_sandcraft(c);
737 		break;
738  	case PRID_COMP_PHILIPS:
739 		cpu_probe_philips(c);
740 		break;
741 	default:
742 		c->cputype = CPU_UNKNOWN;
743 	}
744 	if (c->options & MIPS_CPU_FPU) {
745 		c->fpu_id = cpu_get_fpu_id();
746 
747 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
748 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
749 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
750 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
751 			if (c->fpu_id & MIPS_FPIR_3D)
752 				c->ases |= MIPS_ASE_MIPS3D;
753 		}
754 	}
755 }
756 
757 __init void cpu_report(void)
758 {
759 	struct cpuinfo_mips *c = &current_cpu_data;
760 
761 	printk("CPU revision is: %08x\n", c->processor_id);
762 	if (c->options & MIPS_CPU_FPU)
763 		printk("FPU revision is: %08x\n", c->fpu_id);
764 }
765