xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision c21b37f6)
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 		cpu_wait = r4k_wait;
163 		break;
164 
165 	case CPU_RM7000:
166 		cpu_wait = rm7k_wait_irqoff;
167 		break;
168 
169 	case CPU_24K:
170 	case CPU_34K:
171 		cpu_wait = r4k_wait;
172 		if (read_c0_config7() & MIPS_CONF7_WII)
173 			cpu_wait = r4k_wait_irqoff;
174 		break;
175 
176 	case CPU_74K:
177 		cpu_wait = r4k_wait;
178 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
179 			cpu_wait = r4k_wait_irqoff;
180 		break;
181 
182 	case CPU_TX49XX:
183 		cpu_wait = r4k_wait_irqoff;
184 		break;
185 	case CPU_AU1000:
186 	case CPU_AU1100:
187 	case CPU_AU1500:
188 	case CPU_AU1550:
189 	case CPU_AU1200:
190 		if (allow_au1k_wait)
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 		cpu_wait = r4k_wait;
203 		break;
204 	case CPU_RM9000:
205 		if ((c->processor_id & 0x00ff) >= 0x40)
206 			cpu_wait = r4k_wait;
207 		break;
208 	default:
209 		break;
210 	}
211 }
212 
213 static inline void check_errata(void)
214 {
215 	struct cpuinfo_mips *c = &current_cpu_data;
216 
217 	switch (c->cputype) {
218 	case CPU_34K:
219 		/*
220 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
221 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
222 		 * making use of VPE1 will be responsable for that VPE.
223 		 */
224 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
225 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
226 		break;
227 	default:
228 		break;
229 	}
230 }
231 
232 void __init check_bugs32(void)
233 {
234 	check_wait();
235 	check_errata();
236 }
237 
238 /*
239  * Probe whether cpu has config register by trying to play with
240  * alternate cache bit and see whether it matters.
241  * It's used by cpu_probe to distinguish between R3000A and R3081.
242  */
243 static inline int cpu_has_confreg(void)
244 {
245 #ifdef CONFIG_CPU_R3000
246 	extern unsigned long r3k_cache_size(unsigned long);
247 	unsigned long size1, size2;
248 	unsigned long cfg = read_c0_conf();
249 
250 	size1 = r3k_cache_size(ST0_ISC);
251 	write_c0_conf(cfg ^ R30XX_CONF_AC);
252 	size2 = r3k_cache_size(ST0_ISC);
253 	write_c0_conf(cfg);
254 	return size1 != size2;
255 #else
256 	return 0;
257 #endif
258 }
259 
260 /*
261  * Get the FPU Implementation/Revision.
262  */
263 static inline unsigned long cpu_get_fpu_id(void)
264 {
265 	unsigned long tmp, fpu_id;
266 
267 	tmp = read_c0_status();
268 	__enable_fpu();
269 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
270 	write_c0_status(tmp);
271 	return fpu_id;
272 }
273 
274 /*
275  * Check the CPU has an FPU the official way.
276  */
277 static inline int __cpu_has_fpu(void)
278 {
279 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
280 }
281 
282 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
283 		| MIPS_CPU_COUNTER)
284 
285 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
286 {
287 	switch (c->processor_id & 0xff00) {
288 	case PRID_IMP_R2000:
289 		c->cputype = CPU_R2000;
290 		c->isa_level = MIPS_CPU_ISA_I;
291 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
292 		             MIPS_CPU_NOFPUEX;
293 		if (__cpu_has_fpu())
294 			c->options |= MIPS_CPU_FPU;
295 		c->tlbsize = 64;
296 		break;
297 	case PRID_IMP_R3000:
298 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
299 			if (cpu_has_confreg())
300 				c->cputype = CPU_R3081E;
301 			else
302 				c->cputype = CPU_R3000A;
303 		else
304 			c->cputype = CPU_R3000;
305 		c->isa_level = MIPS_CPU_ISA_I;
306 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
307 		             MIPS_CPU_NOFPUEX;
308 		if (__cpu_has_fpu())
309 			c->options |= MIPS_CPU_FPU;
310 		c->tlbsize = 64;
311 		break;
312 	case PRID_IMP_R4000:
313 		if (read_c0_config() & CONF_SC) {
314 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
315 				c->cputype = CPU_R4400PC;
316 			else
317 				c->cputype = CPU_R4000PC;
318 		} else {
319 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
320 				c->cputype = CPU_R4400SC;
321 			else
322 				c->cputype = CPU_R4000SC;
323 		}
324 
325 		c->isa_level = MIPS_CPU_ISA_III;
326 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
327 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
328 		             MIPS_CPU_LLSC;
329 		c->tlbsize = 48;
330 		break;
331 	case PRID_IMP_VR41XX:
332 		switch (c->processor_id & 0xf0) {
333 		case PRID_REV_VR4111:
334 			c->cputype = CPU_VR4111;
335 			break;
336 		case PRID_REV_VR4121:
337 			c->cputype = CPU_VR4121;
338 			break;
339 		case PRID_REV_VR4122:
340 			if ((c->processor_id & 0xf) < 0x3)
341 				c->cputype = CPU_VR4122;
342 			else
343 				c->cputype = CPU_VR4181A;
344 			break;
345 		case PRID_REV_VR4130:
346 			if ((c->processor_id & 0xf) < 0x4)
347 				c->cputype = CPU_VR4131;
348 			else
349 				c->cputype = CPU_VR4133;
350 			break;
351 		default:
352 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
353 			c->cputype = CPU_VR41XX;
354 			break;
355 		}
356 		c->isa_level = MIPS_CPU_ISA_III;
357 		c->options = R4K_OPTS;
358 		c->tlbsize = 32;
359 		break;
360 	case PRID_IMP_R4300:
361 		c->cputype = CPU_R4300;
362 		c->isa_level = MIPS_CPU_ISA_III;
363 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
364 		             MIPS_CPU_LLSC;
365 		c->tlbsize = 32;
366 		break;
367 	case PRID_IMP_R4600:
368 		c->cputype = CPU_R4600;
369 		c->isa_level = MIPS_CPU_ISA_III;
370 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
371 			     MIPS_CPU_LLSC;
372 		c->tlbsize = 48;
373 		break;
374 	#if 0
375  	case PRID_IMP_R4650:
376 		/*
377 		 * This processor doesn't have an MMU, so it's not
378 		 * "real easy" to run Linux on it. It is left purely
379 		 * for documentation.  Commented out because it shares
380 		 * it's c0_prid id number with the TX3900.
381 		 */
382 		c->cputype = CPU_R4650;
383 	 	c->isa_level = MIPS_CPU_ISA_III;
384 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
385 	        c->tlbsize = 48;
386 		break;
387 	#endif
388 	case PRID_IMP_TX39:
389 		c->isa_level = MIPS_CPU_ISA_I;
390 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
391 
392 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
393 			c->cputype = CPU_TX3927;
394 			c->tlbsize = 64;
395 		} else {
396 			switch (c->processor_id & 0xff) {
397 			case PRID_REV_TX3912:
398 				c->cputype = CPU_TX3912;
399 				c->tlbsize = 32;
400 				break;
401 			case PRID_REV_TX3922:
402 				c->cputype = CPU_TX3922;
403 				c->tlbsize = 64;
404 				break;
405 			default:
406 				c->cputype = CPU_UNKNOWN;
407 				break;
408 			}
409 		}
410 		break;
411 	case PRID_IMP_R4700:
412 		c->cputype = CPU_R4700;
413 		c->isa_level = MIPS_CPU_ISA_III;
414 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
415 		             MIPS_CPU_LLSC;
416 		c->tlbsize = 48;
417 		break;
418 	case PRID_IMP_TX49:
419 		c->cputype = CPU_TX49XX;
420 		c->isa_level = MIPS_CPU_ISA_III;
421 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
422 		if (!(c->processor_id & 0x08))
423 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
424 		c->tlbsize = 48;
425 		break;
426 	case PRID_IMP_R5000:
427 		c->cputype = CPU_R5000;
428 		c->isa_level = MIPS_CPU_ISA_IV;
429 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
430 		             MIPS_CPU_LLSC;
431 		c->tlbsize = 48;
432 		break;
433 	case PRID_IMP_R5432:
434 		c->cputype = CPU_R5432;
435 		c->isa_level = MIPS_CPU_ISA_IV;
436 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
437 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
438 		c->tlbsize = 48;
439 		break;
440 	case PRID_IMP_R5500:
441 		c->cputype = CPU_R5500;
442 		c->isa_level = MIPS_CPU_ISA_IV;
443 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
444 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
445 		c->tlbsize = 48;
446 		break;
447 	case PRID_IMP_NEVADA:
448 		c->cputype = CPU_NEVADA;
449 		c->isa_level = MIPS_CPU_ISA_IV;
450 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
451 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
452 		c->tlbsize = 48;
453 		break;
454 	case PRID_IMP_R6000:
455 		c->cputype = CPU_R6000;
456 		c->isa_level = MIPS_CPU_ISA_II;
457 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
458 		             MIPS_CPU_LLSC;
459 		c->tlbsize = 32;
460 		break;
461 	case PRID_IMP_R6000A:
462 		c->cputype = CPU_R6000A;
463 		c->isa_level = MIPS_CPU_ISA_II;
464 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
465 		             MIPS_CPU_LLSC;
466 		c->tlbsize = 32;
467 		break;
468 	case PRID_IMP_RM7000:
469 		c->cputype = CPU_RM7000;
470 		c->isa_level = MIPS_CPU_ISA_IV;
471 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
472 		             MIPS_CPU_LLSC;
473 		/*
474 		 * Undocumented RM7000:  Bit 29 in the info register of
475 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
476 		 * entries.
477 		 *
478 		 * 29      1 =>    64 entry JTLB
479 		 *         0 =>    48 entry JTLB
480 		 */
481 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
482 		break;
483 	case PRID_IMP_RM9000:
484 		c->cputype = CPU_RM9000;
485 		c->isa_level = MIPS_CPU_ISA_IV;
486 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
487 		             MIPS_CPU_LLSC;
488 		/*
489 		 * Bit 29 in the info register of the RM9000
490 		 * indicates if the TLB has 48 or 64 entries.
491 		 *
492 		 * 29      1 =>    64 entry JTLB
493 		 *         0 =>    48 entry JTLB
494 		 */
495 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
496 		break;
497 	case PRID_IMP_R8000:
498 		c->cputype = CPU_R8000;
499 		c->isa_level = MIPS_CPU_ISA_IV;
500 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
501 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
502 		             MIPS_CPU_LLSC;
503 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
504 		break;
505 	case PRID_IMP_R10000:
506 		c->cputype = CPU_R10000;
507 		c->isa_level = MIPS_CPU_ISA_IV;
508 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
509 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
510 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
511 		             MIPS_CPU_LLSC;
512 		c->tlbsize = 64;
513 		break;
514 	case PRID_IMP_R12000:
515 		c->cputype = CPU_R12000;
516 		c->isa_level = MIPS_CPU_ISA_IV;
517 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
518 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
519 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
520 		             MIPS_CPU_LLSC;
521 		c->tlbsize = 64;
522 		break;
523 	case PRID_IMP_R14000:
524 		c->cputype = CPU_R14000;
525 		c->isa_level = MIPS_CPU_ISA_IV;
526 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
527 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
528 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
529 		             MIPS_CPU_LLSC;
530 		c->tlbsize = 64;
531 		break;
532 	case PRID_IMP_LOONGSON2:
533 		c->cputype = CPU_LOONGSON2;
534 		c->isa_level = MIPS_CPU_ISA_III;
535 		c->options = R4K_OPTS |
536 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
537 			     MIPS_CPU_32FPR;
538 		c->tlbsize = 64;
539 		break;
540 	}
541 }
542 
543 static char unknown_isa[] __initdata = KERN_ERR \
544 	"Unsupported ISA type, c0.config0: %d.";
545 
546 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
547 {
548 	unsigned int config0;
549 	int isa;
550 
551 	config0 = read_c0_config();
552 
553 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
554 		c->options |= MIPS_CPU_TLB;
555 	isa = (config0 & MIPS_CONF_AT) >> 13;
556 	switch (isa) {
557 	case 0:
558 		switch ((config0 & MIPS_CONF_AR) >> 10) {
559 		case 0:
560 			c->isa_level = MIPS_CPU_ISA_M32R1;
561 			break;
562 		case 1:
563 			c->isa_level = MIPS_CPU_ISA_M32R2;
564 			break;
565 		default:
566 			goto unknown;
567 		}
568 		break;
569 	case 2:
570 		switch ((config0 & MIPS_CONF_AR) >> 10) {
571 		case 0:
572 			c->isa_level = MIPS_CPU_ISA_M64R1;
573 			break;
574 		case 1:
575 			c->isa_level = MIPS_CPU_ISA_M64R2;
576 			break;
577 		default:
578 			goto unknown;
579 		}
580 		break;
581 	default:
582 		goto unknown;
583 	}
584 
585 	return config0 & MIPS_CONF_M;
586 
587 unknown:
588 	panic(unknown_isa, config0);
589 }
590 
591 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
592 {
593 	unsigned int config1;
594 
595 	config1 = read_c0_config1();
596 
597 	if (config1 & MIPS_CONF1_MD)
598 		c->ases |= MIPS_ASE_MDMX;
599 	if (config1 & MIPS_CONF1_WR)
600 		c->options |= MIPS_CPU_WATCH;
601 	if (config1 & MIPS_CONF1_CA)
602 		c->ases |= MIPS_ASE_MIPS16;
603 	if (config1 & MIPS_CONF1_EP)
604 		c->options |= MIPS_CPU_EJTAG;
605 	if (config1 & MIPS_CONF1_FP) {
606 		c->options |= MIPS_CPU_FPU;
607 		c->options |= MIPS_CPU_32FPR;
608 	}
609 	if (cpu_has_tlb)
610 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
611 
612 	return config1 & MIPS_CONF_M;
613 }
614 
615 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
616 {
617 	unsigned int config2;
618 
619 	config2 = read_c0_config2();
620 
621 	if (config2 & MIPS_CONF2_SL)
622 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
623 
624 	return config2 & MIPS_CONF_M;
625 }
626 
627 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
628 {
629 	unsigned int config3;
630 
631 	config3 = read_c0_config3();
632 
633 	if (config3 & MIPS_CONF3_SM)
634 		c->ases |= MIPS_ASE_SMARTMIPS;
635 	if (config3 & MIPS_CONF3_DSP)
636 		c->ases |= MIPS_ASE_DSP;
637 	if (config3 & MIPS_CONF3_VINT)
638 		c->options |= MIPS_CPU_VINT;
639 	if (config3 & MIPS_CONF3_VEIC)
640 		c->options |= MIPS_CPU_VEIC;
641 	if (config3 & MIPS_CONF3_MT)
642 	        c->ases |= MIPS_ASE_MIPSMT;
643 	if (config3 & MIPS_CONF3_ULRI)
644 		c->options |= MIPS_CPU_ULRI;
645 
646 	return config3 & MIPS_CONF_M;
647 }
648 
649 static void __init decode_configs(struct cpuinfo_mips *c)
650 {
651 	/* MIPS32 or MIPS64 compliant CPU.  */
652 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
653 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
654 
655 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
656 
657 	/* Read Config registers.  */
658 	if (!decode_config0(c))
659 		return;			/* actually worth a panic() */
660 	if (!decode_config1(c))
661 		return;
662 	if (!decode_config2(c))
663 		return;
664 	if (!decode_config3(c))
665 		return;
666 }
667 
668 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
669 {
670 	decode_configs(c);
671 	switch (c->processor_id & 0xff00) {
672 	case PRID_IMP_4KC:
673 		c->cputype = CPU_4KC;
674 		break;
675 	case PRID_IMP_4KEC:
676 		c->cputype = CPU_4KEC;
677 		break;
678 	case PRID_IMP_4KECR2:
679 		c->cputype = CPU_4KEC;
680 		break;
681 	case PRID_IMP_4KSC:
682 	case PRID_IMP_4KSD:
683 		c->cputype = CPU_4KSC;
684 		break;
685 	case PRID_IMP_5KC:
686 		c->cputype = CPU_5KC;
687 		break;
688 	case PRID_IMP_20KC:
689 		c->cputype = CPU_20KC;
690 		break;
691 	case PRID_IMP_24K:
692 	case PRID_IMP_24KE:
693 		c->cputype = CPU_24K;
694 		break;
695 	case PRID_IMP_25KF:
696 		c->cputype = CPU_25KF;
697 		break;
698 	case PRID_IMP_34K:
699 		c->cputype = CPU_34K;
700 		break;
701 	case PRID_IMP_74K:
702 		c->cputype = CPU_74K;
703 		break;
704 	}
705 }
706 
707 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
708 {
709 	decode_configs(c);
710 	switch (c->processor_id & 0xff00) {
711 	case PRID_IMP_AU1_REV1:
712 	case PRID_IMP_AU1_REV2:
713 		switch ((c->processor_id >> 24) & 0xff) {
714 		case 0:
715 			c->cputype = CPU_AU1000;
716 			break;
717 		case 1:
718 			c->cputype = CPU_AU1500;
719 			break;
720 		case 2:
721 			c->cputype = CPU_AU1100;
722 			break;
723 		case 3:
724 			c->cputype = CPU_AU1550;
725 			break;
726 		case 4:
727 			c->cputype = CPU_AU1200;
728 			break;
729 		default:
730 			panic("Unknown Au Core!");
731 			break;
732 		}
733 		break;
734 	}
735 }
736 
737 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
738 {
739 	decode_configs(c);
740 
741 	/*
742 	 * For historical reasons the SB1 comes with it's own variant of
743 	 * cache code which eventually will be folded into c-r4k.c.  Until
744 	 * then we pretend it's got it's own cache architecture.
745 	 */
746 	c->options &= ~MIPS_CPU_4K_CACHE;
747 	c->options |= MIPS_CPU_SB1_CACHE;
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 __init void cpu_probe(void)
790 {
791 	struct cpuinfo_mips *c = &current_cpu_data;
792 
793 	c->processor_id	= PRID_IMP_UNKNOWN;
794 	c->fpu_id	= FPIR_IMP_NONE;
795 	c->cputype	= CPU_UNKNOWN;
796 
797 	c->processor_id = read_c0_prid();
798 	switch (c->processor_id & 0xff0000) {
799 	case PRID_COMP_LEGACY:
800 		cpu_probe_legacy(c);
801 		break;
802 	case PRID_COMP_MIPS:
803 		cpu_probe_mips(c);
804 		break;
805 	case PRID_COMP_ALCHEMY:
806 		cpu_probe_alchemy(c);
807 		break;
808 	case PRID_COMP_SIBYTE:
809 		cpu_probe_sibyte(c);
810 		break;
811 	case PRID_COMP_SANDCRAFT:
812 		cpu_probe_sandcraft(c);
813 		break;
814  	case PRID_COMP_PHILIPS:
815 		cpu_probe_philips(c);
816 		break;
817 	default:
818 		c->cputype = CPU_UNKNOWN;
819 	}
820 	if (c->options & MIPS_CPU_FPU) {
821 		c->fpu_id = cpu_get_fpu_id();
822 
823 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
824 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
825 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
826 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
827 			if (c->fpu_id & MIPS_FPIR_3D)
828 				c->ases |= MIPS_ASE_MIPS3D;
829 		}
830 	}
831 }
832 
833 __init void cpu_report(void)
834 {
835 	struct cpuinfo_mips *c = &current_cpu_data;
836 
837 	printk("CPU revision is: %08x\n", c->processor_id);
838 	if (c->options & MIPS_CPU_FPU)
839 		printk("FPU revision is: %08x\n", c->fpu_id);
840 }
841