xref: /linux/arch/mips/kernel/cpu-probe.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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/config.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/ptrace.h>
18 #include <linux/stddef.h>
19 
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 	unsigned long cfg = read_c0_conf();
43 	write_c0_conf(cfg | TX39_CONF_HALT);
44 }
45 
46 static void r4k_wait(void)
47 {
48 	__asm__(".set\tmips3\n\t"
49 		"wait\n\t"
50 		".set\tmips0");
51 }
52 
53 /* The Au1xxx wait is available only if using 32khz counter or
54  * external timer source, but specifically not CP0 Counter. */
55 int allow_au1k_wait;
56 
57 static void au1k_wait(void)
58 {
59 	/* using the wait instruction makes CP0 counter unusable */
60 	__asm__(".set mips3\n\t"
61 		"cache 0x14, 0(%0)\n\t"
62 		"cache 0x14, 32(%0)\n\t"
63 		"sync\n\t"
64 		"nop\n\t"
65 		"wait\n\t"
66 		"nop\n\t"
67 		"nop\n\t"
68 		"nop\n\t"
69 		"nop\n\t"
70 		".set mips0\n\t"
71 		: : "r" (au1k_wait));
72 }
73 
74 static int __initdata nowait = 0;
75 
76 int __init wait_disable(char *s)
77 {
78 	nowait = 1;
79 
80 	return 1;
81 }
82 
83 __setup("nowait", wait_disable);
84 
85 static inline void check_wait(void)
86 {
87 	struct cpuinfo_mips *c = &current_cpu_data;
88 
89 	printk("Checking for 'wait' instruction... ");
90 	if (nowait) {
91 		printk (" disabled.\n");
92 		return;
93 	}
94 
95 	switch (c->cputype) {
96 	case CPU_R3081:
97 	case CPU_R3081E:
98 		cpu_wait = r3081_wait;
99 		printk(" available.\n");
100 		break;
101 	case CPU_TX3927:
102 		cpu_wait = r39xx_wait;
103 		printk(" available.\n");
104 		break;
105 	case CPU_R4200:
106 /*	case CPU_R4300: */
107 	case CPU_R4600:
108 	case CPU_R4640:
109 	case CPU_R4650:
110 	case CPU_R4700:
111 	case CPU_R5000:
112 	case CPU_NEVADA:
113 	case CPU_RM7000:
114 	case CPU_RM9000:
115 	case CPU_TX49XX:
116 	case CPU_4KC:
117 	case CPU_4KEC:
118 	case CPU_4KSC:
119 	case CPU_5KC:
120 /*	case CPU_20KC:*/
121 	case CPU_24K:
122 	case CPU_25KF:
123 	case CPU_34K:
124  	case CPU_PR4450:
125 		cpu_wait = r4k_wait;
126 		printk(" available.\n");
127 		break;
128 	case CPU_AU1000:
129 	case CPU_AU1100:
130 	case CPU_AU1500:
131 	case CPU_AU1550:
132 	case CPU_AU1200:
133 		if (allow_au1k_wait) {
134 			cpu_wait = au1k_wait;
135 			printk(" available.\n");
136 		} else
137 			printk(" unavailable.\n");
138 		break;
139 	default:
140 		printk(" unavailable.\n");
141 		break;
142 	}
143 }
144 
145 void __init check_bugs32(void)
146 {
147 	check_wait();
148 }
149 
150 /*
151  * Probe whether cpu has config register by trying to play with
152  * alternate cache bit and see whether it matters.
153  * It's used by cpu_probe to distinguish between R3000A and R3081.
154  */
155 static inline int cpu_has_confreg(void)
156 {
157 #ifdef CONFIG_CPU_R3000
158 	extern unsigned long r3k_cache_size(unsigned long);
159 	unsigned long size1, size2;
160 	unsigned long cfg = read_c0_conf();
161 
162 	size1 = r3k_cache_size(ST0_ISC);
163 	write_c0_conf(cfg ^ R30XX_CONF_AC);
164 	size2 = r3k_cache_size(ST0_ISC);
165 	write_c0_conf(cfg);
166 	return size1 != size2;
167 #else
168 	return 0;
169 #endif
170 }
171 
172 /*
173  * Get the FPU Implementation/Revision.
174  */
175 static inline unsigned long cpu_get_fpu_id(void)
176 {
177 	unsigned long tmp, fpu_id;
178 
179 	tmp = read_c0_status();
180 	__enable_fpu();
181 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
182 	write_c0_status(tmp);
183 	return fpu_id;
184 }
185 
186 /*
187  * Check the CPU has an FPU the official way.
188  */
189 static inline int __cpu_has_fpu(void)
190 {
191 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
192 }
193 
194 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
195 		| MIPS_CPU_COUNTER)
196 
197 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
198 {
199 	switch (c->processor_id & 0xff00) {
200 	case PRID_IMP_R2000:
201 		c->cputype = CPU_R2000;
202 		c->isa_level = MIPS_CPU_ISA_I;
203 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
204 		             MIPS_CPU_NOFPUEX;
205 		if (__cpu_has_fpu())
206 			c->options |= MIPS_CPU_FPU;
207 		c->tlbsize = 64;
208 		break;
209 	case PRID_IMP_R3000:
210 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
211 			if (cpu_has_confreg())
212 				c->cputype = CPU_R3081E;
213 			else
214 				c->cputype = CPU_R3000A;
215 		else
216 			c->cputype = CPU_R3000;
217 		c->isa_level = MIPS_CPU_ISA_I;
218 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
219 		             MIPS_CPU_NOFPUEX;
220 		if (__cpu_has_fpu())
221 			c->options |= MIPS_CPU_FPU;
222 		c->tlbsize = 64;
223 		break;
224 	case PRID_IMP_R4000:
225 		if (read_c0_config() & CONF_SC) {
226 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
227 				c->cputype = CPU_R4400PC;
228 			else
229 				c->cputype = CPU_R4000PC;
230 		} else {
231 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
232 				c->cputype = CPU_R4400SC;
233 			else
234 				c->cputype = CPU_R4000SC;
235 		}
236 
237 		c->isa_level = MIPS_CPU_ISA_III;
238 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
239 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
240 		             MIPS_CPU_LLSC;
241 		c->tlbsize = 48;
242 		break;
243 	case PRID_IMP_VR41XX:
244 		switch (c->processor_id & 0xf0) {
245 		case PRID_REV_VR4111:
246 			c->cputype = CPU_VR4111;
247 			break;
248 		case PRID_REV_VR4121:
249 			c->cputype = CPU_VR4121;
250 			break;
251 		case PRID_REV_VR4122:
252 			if ((c->processor_id & 0xf) < 0x3)
253 				c->cputype = CPU_VR4122;
254 			else
255 				c->cputype = CPU_VR4181A;
256 			break;
257 		case PRID_REV_VR4130:
258 			if ((c->processor_id & 0xf) < 0x4)
259 				c->cputype = CPU_VR4131;
260 			else
261 				c->cputype = CPU_VR4133;
262 			break;
263 		default:
264 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
265 			c->cputype = CPU_VR41XX;
266 			break;
267 		}
268 		c->isa_level = MIPS_CPU_ISA_III;
269 		c->options = R4K_OPTS;
270 		c->tlbsize = 32;
271 		break;
272 	case PRID_IMP_R4300:
273 		c->cputype = CPU_R4300;
274 		c->isa_level = MIPS_CPU_ISA_III;
275 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
276 		             MIPS_CPU_LLSC;
277 		c->tlbsize = 32;
278 		break;
279 	case PRID_IMP_R4600:
280 		c->cputype = CPU_R4600;
281 		c->isa_level = MIPS_CPU_ISA_III;
282 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
283 			     MIPS_CPU_LLSC;
284 		c->tlbsize = 48;
285 		break;
286 	#if 0
287  	case PRID_IMP_R4650:
288 		/*
289 		 * This processor doesn't have an MMU, so it's not
290 		 * "real easy" to run Linux on it. It is left purely
291 		 * for documentation.  Commented out because it shares
292 		 * it's c0_prid id number with the TX3900.
293 		 */
294  		c->cputype = CPU_R4650;
295 	 	c->isa_level = MIPS_CPU_ISA_III;
296 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
297 	        c->tlbsize = 48;
298 		break;
299 	#endif
300 	case PRID_IMP_TX39:
301 		c->isa_level = MIPS_CPU_ISA_I;
302 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
303 
304 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
305 			c->cputype = CPU_TX3927;
306 			c->tlbsize = 64;
307 		} else {
308 			switch (c->processor_id & 0xff) {
309 			case PRID_REV_TX3912:
310 				c->cputype = CPU_TX3912;
311 				c->tlbsize = 32;
312 				break;
313 			case PRID_REV_TX3922:
314 				c->cputype = CPU_TX3922;
315 				c->tlbsize = 64;
316 				break;
317 			default:
318 				c->cputype = CPU_UNKNOWN;
319 				break;
320 			}
321 		}
322 		break;
323 	case PRID_IMP_R4700:
324 		c->cputype = CPU_R4700;
325 		c->isa_level = MIPS_CPU_ISA_III;
326 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
327 		             MIPS_CPU_LLSC;
328 		c->tlbsize = 48;
329 		break;
330 	case PRID_IMP_TX49:
331 		c->cputype = CPU_TX49XX;
332 		c->isa_level = MIPS_CPU_ISA_III;
333 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
334 		if (!(c->processor_id & 0x08))
335 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
336 		c->tlbsize = 48;
337 		break;
338 	case PRID_IMP_R5000:
339 		c->cputype = CPU_R5000;
340 		c->isa_level = MIPS_CPU_ISA_IV;
341 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
342 		             MIPS_CPU_LLSC;
343 		c->tlbsize = 48;
344 		break;
345 	case PRID_IMP_R5432:
346 		c->cputype = CPU_R5432;
347 		c->isa_level = MIPS_CPU_ISA_IV;
348 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
349 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
350 		c->tlbsize = 48;
351 		break;
352 	case PRID_IMP_R5500:
353 		c->cputype = CPU_R5500;
354 		c->isa_level = MIPS_CPU_ISA_IV;
355 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
356 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
357 		c->tlbsize = 48;
358 		break;
359 	case PRID_IMP_NEVADA:
360 		c->cputype = CPU_NEVADA;
361 		c->isa_level = MIPS_CPU_ISA_IV;
362 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
363 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
364 		c->tlbsize = 48;
365 		break;
366 	case PRID_IMP_R6000:
367 		c->cputype = CPU_R6000;
368 		c->isa_level = MIPS_CPU_ISA_II;
369 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
370 		             MIPS_CPU_LLSC;
371 		c->tlbsize = 32;
372 		break;
373 	case PRID_IMP_R6000A:
374 		c->cputype = CPU_R6000A;
375 		c->isa_level = MIPS_CPU_ISA_II;
376 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
377 		             MIPS_CPU_LLSC;
378 		c->tlbsize = 32;
379 		break;
380 	case PRID_IMP_RM7000:
381 		c->cputype = CPU_RM7000;
382 		c->isa_level = MIPS_CPU_ISA_IV;
383 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
384 		             MIPS_CPU_LLSC;
385 		/*
386 		 * Undocumented RM7000:  Bit 29 in the info register of
387 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
388 		 * entries.
389 		 *
390 		 * 29      1 =>    64 entry JTLB
391 		 *         0 =>    48 entry JTLB
392 		 */
393 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
394 		break;
395 	case PRID_IMP_RM9000:
396 		c->cputype = CPU_RM9000;
397 		c->isa_level = MIPS_CPU_ISA_IV;
398 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
399 		             MIPS_CPU_LLSC;
400 		/*
401 		 * Bit 29 in the info register of the RM9000
402 		 * indicates if the TLB has 48 or 64 entries.
403 		 *
404 		 * 29      1 =>    64 entry JTLB
405 		 *         0 =>    48 entry JTLB
406 		 */
407 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
408 		break;
409 	case PRID_IMP_R8000:
410 		c->cputype = CPU_R8000;
411 		c->isa_level = MIPS_CPU_ISA_IV;
412 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
413 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
414 		             MIPS_CPU_LLSC;
415 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
416 		break;
417 	case PRID_IMP_R10000:
418 		c->cputype = CPU_R10000;
419 		c->isa_level = MIPS_CPU_ISA_IV;
420 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
421 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
422 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
423 		             MIPS_CPU_LLSC;
424 		c->tlbsize = 64;
425 		break;
426 	case PRID_IMP_R12000:
427 		c->cputype = CPU_R12000;
428 		c->isa_level = MIPS_CPU_ISA_IV;
429 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
430 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
431 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
432 		             MIPS_CPU_LLSC;
433 		c->tlbsize = 64;
434 		break;
435 	}
436 }
437 
438 static char unknown_isa[] __initdata = KERN_ERR \
439 	"Unsupported ISA type, c0.config0: %d.";
440 
441 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
442 {
443 	unsigned int config0;
444 	int isa;
445 
446 	config0 = read_c0_config();
447 
448 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
449 		c->options |= MIPS_CPU_TLB;
450 	isa = (config0 & MIPS_CONF_AT) >> 13;
451 	switch (isa) {
452 	case 0:
453 		switch ((config0 >> 10) & 7) {
454 		case 0:
455 			c->isa_level = MIPS_CPU_ISA_M32R1;
456 			break;
457 		case 1:
458 			c->isa_level = MIPS_CPU_ISA_M32R2;
459 			break;
460 		default:
461 			goto unknown;
462 		}
463 		break;
464 	case 2:
465 		switch ((config0 >> 10) & 7) {
466 		case 0:
467 			c->isa_level = MIPS_CPU_ISA_M64R1;
468 			break;
469 		case 1:
470 			c->isa_level = MIPS_CPU_ISA_M64R2;
471 			break;
472 		default:
473 			goto unknown;
474 		}
475 		break;
476 	default:
477 		goto unknown;
478 	}
479 
480 	return config0 & MIPS_CONF_M;
481 
482 unknown:
483 	panic(unknown_isa, config0);
484 }
485 
486 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
487 {
488 	unsigned int config1;
489 
490 	config1 = read_c0_config1();
491 
492 	if (config1 & MIPS_CONF1_MD)
493 		c->ases |= MIPS_ASE_MDMX;
494 	if (config1 & MIPS_CONF1_WR)
495 		c->options |= MIPS_CPU_WATCH;
496 	if (config1 & MIPS_CONF1_CA)
497 		c->ases |= MIPS_ASE_MIPS16;
498 	if (config1 & MIPS_CONF1_EP)
499 		c->options |= MIPS_CPU_EJTAG;
500 	if (config1 & MIPS_CONF1_FP) {
501 		c->options |= MIPS_CPU_FPU;
502 		c->options |= MIPS_CPU_32FPR;
503 	}
504 	if (cpu_has_tlb)
505 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
506 
507 	return config1 & MIPS_CONF_M;
508 }
509 
510 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
511 {
512 	unsigned int config2;
513 
514 	config2 = read_c0_config2();
515 
516 	if (config2 & MIPS_CONF2_SL)
517 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
518 
519 	return config2 & MIPS_CONF_M;
520 }
521 
522 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
523 {
524 	unsigned int config3;
525 
526 	config3 = read_c0_config3();
527 
528 	if (config3 & MIPS_CONF3_SM)
529 		c->ases |= MIPS_ASE_SMARTMIPS;
530 	if (config3 & MIPS_CONF3_DSP)
531 		c->ases |= MIPS_ASE_DSP;
532 	if (config3 & MIPS_CONF3_VINT)
533 		c->options |= MIPS_CPU_VINT;
534 	if (config3 & MIPS_CONF3_VEIC)
535 		c->options |= MIPS_CPU_VEIC;
536 	if (config3 & MIPS_CONF3_MT)
537                 c->ases |= MIPS_ASE_MIPSMT;
538 
539 	return config3 & MIPS_CONF_M;
540 }
541 
542 static inline void decode_configs(struct cpuinfo_mips *c)
543 {
544 	/* MIPS32 or MIPS64 compliant CPU.  */
545 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
546 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
547 
548 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
549 
550 	/* Read Config registers.  */
551 	if (!decode_config0(c))
552 		return;			/* actually worth a panic() */
553 	if (!decode_config1(c))
554 		return;
555 	if (!decode_config2(c))
556 		return;
557 	if (!decode_config3(c))
558 		return;
559 }
560 
561 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
562 {
563 	decode_configs(c);
564 	switch (c->processor_id & 0xff00) {
565 	case PRID_IMP_4KC:
566 		c->cputype = CPU_4KC;
567 		break;
568 	case PRID_IMP_4KEC:
569 		c->cputype = CPU_4KEC;
570 		break;
571 	case PRID_IMP_4KECR2:
572 		c->cputype = CPU_4KEC;
573 		break;
574 	case PRID_IMP_4KSC:
575 	case PRID_IMP_4KSD:
576 		c->cputype = CPU_4KSC;
577 		break;
578 	case PRID_IMP_5KC:
579 		c->cputype = CPU_5KC;
580 		break;
581 	case PRID_IMP_20KC:
582 		c->cputype = CPU_20KC;
583 		break;
584 	case PRID_IMP_24K:
585 	case PRID_IMP_24KE:
586 		c->cputype = CPU_24K;
587 		break;
588 	case PRID_IMP_25KF:
589 		c->cputype = CPU_25KF;
590 		/* Probe for L2 cache */
591 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
592 		break;
593 	case PRID_IMP_34K:
594 		c->cputype = CPU_34K;
595 		break;
596 	}
597 }
598 
599 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
600 {
601 	decode_configs(c);
602 	switch (c->processor_id & 0xff00) {
603 	case PRID_IMP_AU1_REV1:
604 	case PRID_IMP_AU1_REV2:
605 		switch ((c->processor_id >> 24) & 0xff) {
606 		case 0:
607  			c->cputype = CPU_AU1000;
608 			break;
609 		case 1:
610 			c->cputype = CPU_AU1500;
611 			break;
612 		case 2:
613 			c->cputype = CPU_AU1100;
614 			break;
615 		case 3:
616 			c->cputype = CPU_AU1550;
617 			break;
618 		case 4:
619 			c->cputype = CPU_AU1200;
620 			break;
621 		default:
622 			panic("Unknown Au Core!");
623 			break;
624 		}
625 		break;
626 	}
627 }
628 
629 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
630 {
631 	decode_configs(c);
632 
633 	/*
634 	 * For historical reasons the SB1 comes with it's own variant of
635 	 * cache code which eventually will be folded into c-r4k.c.  Until
636 	 * then we pretend it's got it's own cache architecture.
637 	 */
638 	c->options &= ~MIPS_CPU_4K_CACHE;
639 	c->options |= MIPS_CPU_SB1_CACHE;
640 
641 	switch (c->processor_id & 0xff00) {
642 	case PRID_IMP_SB1:
643 		c->cputype = CPU_SB1;
644 		/* FPU in pass1 is known to have issues. */
645 		if ((c->processor_id & 0xff) < 0x20)
646 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
647 		break;
648 	case PRID_IMP_SB1A:
649 		c->cputype = CPU_SB1A;
650 		break;
651 	}
652 }
653 
654 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
655 {
656 	decode_configs(c);
657 	switch (c->processor_id & 0xff00) {
658 	case PRID_IMP_SR71000:
659 		c->cputype = CPU_SR71000;
660 		c->scache.ways = 8;
661 		c->tlbsize = 64;
662 		break;
663 	}
664 }
665 
666 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
667 {
668 	decode_configs(c);
669 	switch (c->processor_id & 0xff00) {
670 	case PRID_IMP_PR4450:
671 		c->cputype = CPU_PR4450;
672 		c->isa_level = MIPS_CPU_ISA_M32R1;
673 		break;
674 	default:
675 		panic("Unknown Philips Core!"); /* REVISIT: die? */
676 		break;
677 	}
678 }
679 
680 
681 __init void cpu_probe(void)
682 {
683 	struct cpuinfo_mips *c = &current_cpu_data;
684 
685 	c->processor_id	= PRID_IMP_UNKNOWN;
686 	c->fpu_id	= FPIR_IMP_NONE;
687 	c->cputype	= CPU_UNKNOWN;
688 
689 	c->processor_id = read_c0_prid();
690 	switch (c->processor_id & 0xff0000) {
691 	case PRID_COMP_LEGACY:
692 		cpu_probe_legacy(c);
693 		break;
694 	case PRID_COMP_MIPS:
695 		cpu_probe_mips(c);
696 		break;
697 	case PRID_COMP_ALCHEMY:
698 		cpu_probe_alchemy(c);
699 		break;
700 	case PRID_COMP_SIBYTE:
701 		cpu_probe_sibyte(c);
702 		break;
703 	case PRID_COMP_SANDCRAFT:
704 		cpu_probe_sandcraft(c);
705 		break;
706  	case PRID_COMP_PHILIPS:
707 		cpu_probe_philips(c);
708  		break;
709 	default:
710 		c->cputype = CPU_UNKNOWN;
711 	}
712 	if (c->options & MIPS_CPU_FPU) {
713 		c->fpu_id = cpu_get_fpu_id();
714 
715 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
716 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
717 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
718 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
719 			if (c->fpu_id & MIPS_FPIR_3D)
720 				c->ases |= MIPS_ASE_MIPS3D;
721 		}
722 	}
723 }
724 
725 __init void cpu_report(void)
726 {
727 	struct cpuinfo_mips *c = &current_cpu_data;
728 
729 	printk("CPU revision is: %08x\n", c->processor_id);
730 	if (c->options & MIPS_CPU_FPU)
731 		printk("FPU revision is: %08x\n", c->fpu_id);
732 }
733