xref: /linux/arch/mips/kernel/cpu-probe.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 	unsigned long cfg = read_c0_conf();
42 	write_c0_conf(cfg | TX39_CONF_HALT);
43 }
44 
45 static void r4k_wait(void)
46 {
47 	__asm__(".set\tmips3\n\t"
48 		"wait\n\t"
49 		".set\tmips0");
50 }
51 
52 /* The Au1xxx wait is available only if using 32khz counter or
53  * external timer source, but specifically not CP0 Counter. */
54 int allow_au1k_wait;
55 
56 static void au1k_wait(void)
57 {
58 	/* using the wait instruction makes CP0 counter unusable */
59 	__asm__(".set mips3\n\t"
60 		"cache 0x14, 0(%0)\n\t"
61 		"cache 0x14, 32(%0)\n\t"
62 		"sync\n\t"
63 		"nop\n\t"
64 		"wait\n\t"
65 		"nop\n\t"
66 		"nop\n\t"
67 		"nop\n\t"
68 		"nop\n\t"
69 		".set mips0\n\t"
70 		: : "r" (au1k_wait));
71 }
72 
73 static int __initdata nowait = 0;
74 
75 int __init wait_disable(char *s)
76 {
77 	nowait = 1;
78 
79 	return 1;
80 }
81 
82 __setup("nowait", wait_disable);
83 
84 static inline void check_wait(void)
85 {
86 	struct cpuinfo_mips *c = &current_cpu_data;
87 
88 	printk("Checking for 'wait' instruction... ");
89 	if (nowait) {
90 		printk (" disabled.\n");
91 		return;
92 	}
93 
94 	switch (c->cputype) {
95 	case CPU_R3081:
96 	case CPU_R3081E:
97 		cpu_wait = r3081_wait;
98 		printk(" available.\n");
99 		break;
100 	case CPU_TX3927:
101 		cpu_wait = r39xx_wait;
102 		printk(" available.\n");
103 		break;
104 	case CPU_R4200:
105 /*	case CPU_R4300: */
106 	case CPU_R4600:
107 	case CPU_R4640:
108 	case CPU_R4650:
109 	case CPU_R4700:
110 	case CPU_R5000:
111 	case CPU_NEVADA:
112 	case CPU_RM7000:
113 	case CPU_RM9000:
114 	case CPU_TX49XX:
115 	case CPU_4KC:
116 	case CPU_4KEC:
117 	case CPU_4KSC:
118 	case CPU_5KC:
119 /*	case CPU_20KC:*/
120 	case CPU_24K:
121 	case CPU_25KF:
122 	case CPU_34K:
123 	case CPU_74K:
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 	case PRID_IMP_R14000:
436 		c->cputype = CPU_R14000;
437 		c->isa_level = MIPS_CPU_ISA_IV;
438 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
439 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
440 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
441 		             MIPS_CPU_LLSC;
442 		c->tlbsize = 64;
443 		break;
444 	}
445 }
446 
447 static char unknown_isa[] __initdata = KERN_ERR \
448 	"Unsupported ISA type, c0.config0: %d.";
449 
450 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
451 {
452 	unsigned int config0;
453 	int isa;
454 
455 	config0 = read_c0_config();
456 
457 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
458 		c->options |= MIPS_CPU_TLB;
459 	isa = (config0 & MIPS_CONF_AT) >> 13;
460 	switch (isa) {
461 	case 0:
462 		switch ((config0 >> 10) & 7) {
463 		case 0:
464 			c->isa_level = MIPS_CPU_ISA_M32R1;
465 			break;
466 		case 1:
467 			c->isa_level = MIPS_CPU_ISA_M32R2;
468 			break;
469 		default:
470 			goto unknown;
471 		}
472 		break;
473 	case 2:
474 		switch ((config0 >> 10) & 7) {
475 		case 0:
476 			c->isa_level = MIPS_CPU_ISA_M64R1;
477 			break;
478 		case 1:
479 			c->isa_level = MIPS_CPU_ISA_M64R2;
480 			break;
481 		default:
482 			goto unknown;
483 		}
484 		break;
485 	default:
486 		goto unknown;
487 	}
488 
489 	return config0 & MIPS_CONF_M;
490 
491 unknown:
492 	panic(unknown_isa, config0);
493 }
494 
495 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
496 {
497 	unsigned int config1;
498 
499 	config1 = read_c0_config1();
500 
501 	if (config1 & MIPS_CONF1_MD)
502 		c->ases |= MIPS_ASE_MDMX;
503 	if (config1 & MIPS_CONF1_WR)
504 		c->options |= MIPS_CPU_WATCH;
505 	if (config1 & MIPS_CONF1_CA)
506 		c->ases |= MIPS_ASE_MIPS16;
507 	if (config1 & MIPS_CONF1_EP)
508 		c->options |= MIPS_CPU_EJTAG;
509 	if (config1 & MIPS_CONF1_FP) {
510 		c->options |= MIPS_CPU_FPU;
511 		c->options |= MIPS_CPU_32FPR;
512 	}
513 	if (cpu_has_tlb)
514 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
515 
516 	return config1 & MIPS_CONF_M;
517 }
518 
519 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
520 {
521 	unsigned int config2;
522 
523 	config2 = read_c0_config2();
524 
525 	if (config2 & MIPS_CONF2_SL)
526 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
527 
528 	return config2 & MIPS_CONF_M;
529 }
530 
531 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
532 {
533 	unsigned int config3;
534 
535 	config3 = read_c0_config3();
536 
537 	if (config3 & MIPS_CONF3_SM)
538 		c->ases |= MIPS_ASE_SMARTMIPS;
539 	if (config3 & MIPS_CONF3_DSP)
540 		c->ases |= MIPS_ASE_DSP;
541 	if (config3 & MIPS_CONF3_VINT)
542 		c->options |= MIPS_CPU_VINT;
543 	if (config3 & MIPS_CONF3_VEIC)
544 		c->options |= MIPS_CPU_VEIC;
545 	if (config3 & MIPS_CONF3_MT)
546                 c->ases |= MIPS_ASE_MIPSMT;
547 
548 	return config3 & MIPS_CONF_M;
549 }
550 
551 static inline void decode_configs(struct cpuinfo_mips *c)
552 {
553 	/* MIPS32 or MIPS64 compliant CPU.  */
554 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
555 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
556 
557 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
558 
559 	/* Read Config registers.  */
560 	if (!decode_config0(c))
561 		return;			/* actually worth a panic() */
562 	if (!decode_config1(c))
563 		return;
564 	if (!decode_config2(c))
565 		return;
566 	if (!decode_config3(c))
567 		return;
568 }
569 
570 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
571 {
572 	decode_configs(c);
573 	switch (c->processor_id & 0xff00) {
574 	case PRID_IMP_4KC:
575 		c->cputype = CPU_4KC;
576 		break;
577 	case PRID_IMP_4KEC:
578 		c->cputype = CPU_4KEC;
579 		break;
580 	case PRID_IMP_4KECR2:
581 		c->cputype = CPU_4KEC;
582 		break;
583 	case PRID_IMP_4KSC:
584 	case PRID_IMP_4KSD:
585 		c->cputype = CPU_4KSC;
586 		break;
587 	case PRID_IMP_5KC:
588 		c->cputype = CPU_5KC;
589 		break;
590 	case PRID_IMP_20KC:
591 		c->cputype = CPU_20KC;
592 		break;
593 	case PRID_IMP_24K:
594 	case PRID_IMP_24KE:
595 		c->cputype = CPU_24K;
596 		break;
597 	case PRID_IMP_25KF:
598 		c->cputype = CPU_25KF;
599 		break;
600 	case PRID_IMP_34K:
601 		c->cputype = CPU_34K;
602 		break;
603 	case PRID_IMP_74K:
604 		c->cputype = CPU_74K;
605 		break;
606 	}
607 }
608 
609 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
610 {
611 	decode_configs(c);
612 	switch (c->processor_id & 0xff00) {
613 	case PRID_IMP_AU1_REV1:
614 	case PRID_IMP_AU1_REV2:
615 		switch ((c->processor_id >> 24) & 0xff) {
616 		case 0:
617 			c->cputype = CPU_AU1000;
618 			break;
619 		case 1:
620 			c->cputype = CPU_AU1500;
621 			break;
622 		case 2:
623 			c->cputype = CPU_AU1100;
624 			break;
625 		case 3:
626 			c->cputype = CPU_AU1550;
627 			break;
628 		case 4:
629 			c->cputype = CPU_AU1200;
630 			break;
631 		default:
632 			panic("Unknown Au Core!");
633 			break;
634 		}
635 		break;
636 	}
637 }
638 
639 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
640 {
641 	decode_configs(c);
642 
643 	/*
644 	 * For historical reasons the SB1 comes with it's own variant of
645 	 * cache code which eventually will be folded into c-r4k.c.  Until
646 	 * then we pretend it's got it's own cache architecture.
647 	 */
648 	c->options &= ~MIPS_CPU_4K_CACHE;
649 	c->options |= MIPS_CPU_SB1_CACHE;
650 
651 	switch (c->processor_id & 0xff00) {
652 	case PRID_IMP_SB1:
653 		c->cputype = CPU_SB1;
654 		/* FPU in pass1 is known to have issues. */
655 		if ((c->processor_id & 0xff) < 0x02)
656 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
657 		break;
658 	case PRID_IMP_SB1A:
659 		c->cputype = CPU_SB1A;
660 		break;
661 	}
662 }
663 
664 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
665 {
666 	decode_configs(c);
667 	switch (c->processor_id & 0xff00) {
668 	case PRID_IMP_SR71000:
669 		c->cputype = CPU_SR71000;
670 		c->scache.ways = 8;
671 		c->tlbsize = 64;
672 		break;
673 	}
674 }
675 
676 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
677 {
678 	decode_configs(c);
679 	switch (c->processor_id & 0xff00) {
680 	case PRID_IMP_PR4450:
681 		c->cputype = CPU_PR4450;
682 		c->isa_level = MIPS_CPU_ISA_M32R1;
683 		break;
684 	default:
685 		panic("Unknown Philips Core!"); /* REVISIT: die? */
686 		break;
687 	}
688 }
689 
690 
691 __init void cpu_probe(void)
692 {
693 	struct cpuinfo_mips *c = &current_cpu_data;
694 
695 	c->processor_id	= PRID_IMP_UNKNOWN;
696 	c->fpu_id	= FPIR_IMP_NONE;
697 	c->cputype	= CPU_UNKNOWN;
698 
699 	c->processor_id = read_c0_prid();
700 	switch (c->processor_id & 0xff0000) {
701 	case PRID_COMP_LEGACY:
702 		cpu_probe_legacy(c);
703 		break;
704 	case PRID_COMP_MIPS:
705 		cpu_probe_mips(c);
706 		break;
707 	case PRID_COMP_ALCHEMY:
708 		cpu_probe_alchemy(c);
709 		break;
710 	case PRID_COMP_SIBYTE:
711 		cpu_probe_sibyte(c);
712 		break;
713 	case PRID_COMP_SANDCRAFT:
714 		cpu_probe_sandcraft(c);
715 		break;
716  	case PRID_COMP_PHILIPS:
717 		cpu_probe_philips(c);
718 		break;
719 	default:
720 		c->cputype = CPU_UNKNOWN;
721 	}
722 	if (c->options & MIPS_CPU_FPU) {
723 		c->fpu_id = cpu_get_fpu_id();
724 
725 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
726 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
727 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
728 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
729 			if (c->fpu_id & MIPS_FPIR_3D)
730 				c->ases |= MIPS_ASE_MIPS3D;
731 		}
732 	}
733 }
734 
735 __init void cpu_report(void)
736 {
737 	struct cpuinfo_mips *c = &current_cpu_data;
738 
739 	printk("CPU revision is: %08x\n", c->processor_id);
740 	if (c->options & MIPS_CPU_FPU)
741 		printk("FPU revision is: %08x\n", c->fpu_id);
742 }
743