xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 384740dc)
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 extern void r4k_wait(void);
49 
50 /*
51  * This variant is preferable as it allows testing need_resched and going to
52  * sleep depending on the outcome atomically.  Unfortunately the "It is
53  * implementation-dependent whether the pipeline restarts when a non-enabled
54  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
55  * using this version a gamble.
56  */
57 void r4k_wait_irqoff(void)
58 {
59 	local_irq_disable();
60 	if (!need_resched())
61 		__asm__("	.set	push		\n"
62 			"	.set	mips3		\n"
63 			"	wait			\n"
64 			"	.set	pop		\n");
65 	local_irq_enable();
66 	__asm__(" 	.globl __pastwait	\n"
67 		"__pastwait:			\n");
68 	return;
69 }
70 
71 /*
72  * The RM7000 variant has to handle erratum 38.  The workaround is to not
73  * have any pending stores when the WAIT instruction is executed.
74  */
75 static void rm7k_wait_irqoff(void)
76 {
77 	local_irq_disable();
78 	if (!need_resched())
79 		__asm__(
80 		"	.set	push					\n"
81 		"	.set	mips3					\n"
82 		"	.set	noat					\n"
83 		"	mfc0	$1, $12					\n"
84 		"	sync						\n"
85 		"	mtc0	$1, $12		# stalls until W stage	\n"
86 		"	wait						\n"
87 		"	mtc0	$1, $12		# stalls until W stage	\n"
88 		"	.set	pop					\n");
89 	local_irq_enable();
90 }
91 
92 /* The Au1xxx wait is available only if using 32khz counter or
93  * external timer source, but specifically not CP0 Counter. */
94 int allow_au1k_wait;
95 
96 static void au1k_wait(void)
97 {
98 	/* using the wait instruction makes CP0 counter unusable */
99 	__asm__("	.set	mips3			\n"
100 		"	cache	0x14, 0(%0)		\n"
101 		"	cache	0x14, 32(%0)		\n"
102 		"	sync				\n"
103 		"	nop				\n"
104 		"	wait				\n"
105 		"	nop				\n"
106 		"	nop				\n"
107 		"	nop				\n"
108 		"	nop				\n"
109 		"	.set	mips0			\n"
110 		: : "r" (au1k_wait));
111 }
112 
113 static int __initdata nowait = 0;
114 
115 static int __init wait_disable(char *s)
116 {
117 	nowait = 1;
118 
119 	return 1;
120 }
121 
122 __setup("nowait", wait_disable);
123 
124 void __init check_wait(void)
125 {
126 	struct cpuinfo_mips *c = &current_cpu_data;
127 
128 	if (nowait) {
129 		printk("Wait instruction disabled.\n");
130 		return;
131 	}
132 
133 	switch (c->cputype) {
134 	case CPU_R3081:
135 	case CPU_R3081E:
136 		cpu_wait = r3081_wait;
137 		break;
138 	case CPU_TX3927:
139 		cpu_wait = r39xx_wait;
140 		break;
141 	case CPU_R4200:
142 /*	case CPU_R4300: */
143 	case CPU_R4600:
144 	case CPU_R4640:
145 	case CPU_R4650:
146 	case CPU_R4700:
147 	case CPU_R5000:
148 	case CPU_NEVADA:
149 	case CPU_4KC:
150 	case CPU_4KEC:
151 	case CPU_4KSC:
152 	case CPU_5KC:
153 	case CPU_25KF:
154 	case CPU_PR4450:
155 	case CPU_BCM3302:
156 		cpu_wait = r4k_wait;
157 		break;
158 
159 	case CPU_RM7000:
160 		cpu_wait = rm7k_wait_irqoff;
161 		break;
162 
163 	case CPU_24K:
164 	case CPU_34K:
165 	case CPU_1004K:
166 		cpu_wait = r4k_wait;
167 		if (read_c0_config7() & MIPS_CONF7_WII)
168 			cpu_wait = r4k_wait_irqoff;
169 		break;
170 
171 	case CPU_74K:
172 		cpu_wait = r4k_wait;
173 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
174 			cpu_wait = r4k_wait_irqoff;
175 		break;
176 
177 	case CPU_TX49XX:
178 		cpu_wait = r4k_wait_irqoff;
179 		break;
180 	case CPU_AU1000:
181 	case CPU_AU1100:
182 	case CPU_AU1500:
183 	case CPU_AU1550:
184 	case CPU_AU1200:
185 	case CPU_AU1210:
186 	case CPU_AU1250:
187 		if (allow_au1k_wait)
188 			cpu_wait = au1k_wait;
189 		break;
190 	case CPU_20KC:
191 		/*
192 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
193 		 * WAIT on Rev2.0 and Rev3.0 has E16.
194 		 * Rev3.1 WAIT is nop, why bother
195 		 */
196 		if ((c->processor_id & 0xff) <= 0x64)
197 			break;
198 
199 		/*
200 		 * Another rev is incremeting c0_count at a reduced clock
201 		 * rate while in WAIT mode.  So we basically have the choice
202 		 * between using the cp0 timer as clocksource or avoiding
203 		 * the WAIT instruction.  Until more details are known,
204 		 * disable the use of WAIT for 20Kc entirely.
205 		   cpu_wait = r4k_wait;
206 		 */
207 		break;
208 	case CPU_RM9000:
209 		if ((c->processor_id & 0x00ff) >= 0x40)
210 			cpu_wait = r4k_wait;
211 		break;
212 	default:
213 		break;
214 	}
215 }
216 
217 static inline void check_errata(void)
218 {
219 	struct cpuinfo_mips *c = &current_cpu_data;
220 
221 	switch (c->cputype) {
222 	case CPU_34K:
223 		/*
224 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
225 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
226 		 * making use of VPE1 will be responsable for that VPE.
227 		 */
228 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
229 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
230 		break;
231 	default:
232 		break;
233 	}
234 }
235 
236 void __init check_bugs32(void)
237 {
238 	check_errata();
239 }
240 
241 /*
242  * Probe whether cpu has config register by trying to play with
243  * alternate cache bit and see whether it matters.
244  * It's used by cpu_probe to distinguish between R3000A and R3081.
245  */
246 static inline int cpu_has_confreg(void)
247 {
248 #ifdef CONFIG_CPU_R3000
249 	extern unsigned long r3k_cache_size(unsigned long);
250 	unsigned long size1, size2;
251 	unsigned long cfg = read_c0_conf();
252 
253 	size1 = r3k_cache_size(ST0_ISC);
254 	write_c0_conf(cfg ^ R30XX_CONF_AC);
255 	size2 = r3k_cache_size(ST0_ISC);
256 	write_c0_conf(cfg);
257 	return size1 != size2;
258 #else
259 	return 0;
260 #endif
261 }
262 
263 /*
264  * Get the FPU Implementation/Revision.
265  */
266 static inline unsigned long cpu_get_fpu_id(void)
267 {
268 	unsigned long tmp, fpu_id;
269 
270 	tmp = read_c0_status();
271 	__enable_fpu();
272 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
273 	write_c0_status(tmp);
274 	return fpu_id;
275 }
276 
277 /*
278  * Check the CPU has an FPU the official way.
279  */
280 static inline int __cpu_has_fpu(void)
281 {
282 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
283 }
284 
285 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
286 		| MIPS_CPU_COUNTER)
287 
288 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
289 {
290 	switch (c->processor_id & 0xff00) {
291 	case PRID_IMP_R2000:
292 		c->cputype = CPU_R2000;
293 		c->isa_level = MIPS_CPU_ISA_I;
294 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
295 		             MIPS_CPU_NOFPUEX;
296 		if (__cpu_has_fpu())
297 			c->options |= MIPS_CPU_FPU;
298 		c->tlbsize = 64;
299 		break;
300 	case PRID_IMP_R3000:
301 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
302 			if (cpu_has_confreg())
303 				c->cputype = CPU_R3081E;
304 			else
305 				c->cputype = CPU_R3000A;
306 		else
307 			c->cputype = CPU_R3000;
308 		c->isa_level = MIPS_CPU_ISA_I;
309 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
310 		             MIPS_CPU_NOFPUEX;
311 		if (__cpu_has_fpu())
312 			c->options |= MIPS_CPU_FPU;
313 		c->tlbsize = 64;
314 		break;
315 	case PRID_IMP_R4000:
316 		if (read_c0_config() & CONF_SC) {
317 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
318 				c->cputype = CPU_R4400PC;
319 			else
320 				c->cputype = CPU_R4000PC;
321 		} else {
322 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
323 				c->cputype = CPU_R4400SC;
324 			else
325 				c->cputype = CPU_R4000SC;
326 		}
327 
328 		c->isa_level = MIPS_CPU_ISA_III;
329 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
330 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
331 		             MIPS_CPU_LLSC;
332 		c->tlbsize = 48;
333 		break;
334 	case PRID_IMP_VR41XX:
335 		switch (c->processor_id & 0xf0) {
336 		case PRID_REV_VR4111:
337 			c->cputype = CPU_VR4111;
338 			break;
339 		case PRID_REV_VR4121:
340 			c->cputype = CPU_VR4121;
341 			break;
342 		case PRID_REV_VR4122:
343 			if ((c->processor_id & 0xf) < 0x3)
344 				c->cputype = CPU_VR4122;
345 			else
346 				c->cputype = CPU_VR4181A;
347 			break;
348 		case PRID_REV_VR4130:
349 			if ((c->processor_id & 0xf) < 0x4)
350 				c->cputype = CPU_VR4131;
351 			else
352 				c->cputype = CPU_VR4133;
353 			break;
354 		default:
355 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
356 			c->cputype = CPU_VR41XX;
357 			break;
358 		}
359 		c->isa_level = MIPS_CPU_ISA_III;
360 		c->options = R4K_OPTS;
361 		c->tlbsize = 32;
362 		break;
363 	case PRID_IMP_R4300:
364 		c->cputype = CPU_R4300;
365 		c->isa_level = MIPS_CPU_ISA_III;
366 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
367 		             MIPS_CPU_LLSC;
368 		c->tlbsize = 32;
369 		break;
370 	case PRID_IMP_R4600:
371 		c->cputype = CPU_R4600;
372 		c->isa_level = MIPS_CPU_ISA_III;
373 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
374 			     MIPS_CPU_LLSC;
375 		c->tlbsize = 48;
376 		break;
377 	#if 0
378  	case PRID_IMP_R4650:
379 		/*
380 		 * This processor doesn't have an MMU, so it's not
381 		 * "real easy" to run Linux on it. It is left purely
382 		 * for documentation.  Commented out because it shares
383 		 * it's c0_prid id number with the TX3900.
384 		 */
385 		c->cputype = CPU_R4650;
386 	 	c->isa_level = MIPS_CPU_ISA_III;
387 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
388 	        c->tlbsize = 48;
389 		break;
390 	#endif
391 	case PRID_IMP_TX39:
392 		c->isa_level = MIPS_CPU_ISA_I;
393 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
394 
395 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
396 			c->cputype = CPU_TX3927;
397 			c->tlbsize = 64;
398 		} else {
399 			switch (c->processor_id & 0xff) {
400 			case PRID_REV_TX3912:
401 				c->cputype = CPU_TX3912;
402 				c->tlbsize = 32;
403 				break;
404 			case PRID_REV_TX3922:
405 				c->cputype = CPU_TX3922;
406 				c->tlbsize = 64;
407 				break;
408 			default:
409 				c->cputype = CPU_UNKNOWN;
410 				break;
411 			}
412 		}
413 		break;
414 	case PRID_IMP_R4700:
415 		c->cputype = CPU_R4700;
416 		c->isa_level = MIPS_CPU_ISA_III;
417 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
418 		             MIPS_CPU_LLSC;
419 		c->tlbsize = 48;
420 		break;
421 	case PRID_IMP_TX49:
422 		c->cputype = CPU_TX49XX;
423 		c->isa_level = MIPS_CPU_ISA_III;
424 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
425 		if (!(c->processor_id & 0x08))
426 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
427 		c->tlbsize = 48;
428 		break;
429 	case PRID_IMP_R5000:
430 		c->cputype = CPU_R5000;
431 		c->isa_level = MIPS_CPU_ISA_IV;
432 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
433 		             MIPS_CPU_LLSC;
434 		c->tlbsize = 48;
435 		break;
436 	case PRID_IMP_R5432:
437 		c->cputype = CPU_R5432;
438 		c->isa_level = MIPS_CPU_ISA_IV;
439 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
440 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
441 		c->tlbsize = 48;
442 		break;
443 	case PRID_IMP_R5500:
444 		c->cputype = CPU_R5500;
445 		c->isa_level = MIPS_CPU_ISA_IV;
446 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
447 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
448 		c->tlbsize = 48;
449 		break;
450 	case PRID_IMP_NEVADA:
451 		c->cputype = CPU_NEVADA;
452 		c->isa_level = MIPS_CPU_ISA_IV;
453 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
454 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
455 		c->tlbsize = 48;
456 		break;
457 	case PRID_IMP_R6000:
458 		c->cputype = CPU_R6000;
459 		c->isa_level = MIPS_CPU_ISA_II;
460 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
461 		             MIPS_CPU_LLSC;
462 		c->tlbsize = 32;
463 		break;
464 	case PRID_IMP_R6000A:
465 		c->cputype = CPU_R6000A;
466 		c->isa_level = MIPS_CPU_ISA_II;
467 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
468 		             MIPS_CPU_LLSC;
469 		c->tlbsize = 32;
470 		break;
471 	case PRID_IMP_RM7000:
472 		c->cputype = CPU_RM7000;
473 		c->isa_level = MIPS_CPU_ISA_IV;
474 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
475 		             MIPS_CPU_LLSC;
476 		/*
477 		 * Undocumented RM7000:  Bit 29 in the info register of
478 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
479 		 * entries.
480 		 *
481 		 * 29      1 =>    64 entry JTLB
482 		 *         0 =>    48 entry JTLB
483 		 */
484 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
485 		break;
486 	case PRID_IMP_RM9000:
487 		c->cputype = CPU_RM9000;
488 		c->isa_level = MIPS_CPU_ISA_IV;
489 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
490 		             MIPS_CPU_LLSC;
491 		/*
492 		 * Bit 29 in the info register of the RM9000
493 		 * indicates if the TLB has 48 or 64 entries.
494 		 *
495 		 * 29      1 =>    64 entry JTLB
496 		 *         0 =>    48 entry JTLB
497 		 */
498 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
499 		break;
500 	case PRID_IMP_R8000:
501 		c->cputype = CPU_R8000;
502 		c->isa_level = MIPS_CPU_ISA_IV;
503 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
504 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
505 		             MIPS_CPU_LLSC;
506 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
507 		break;
508 	case PRID_IMP_R10000:
509 		c->cputype = CPU_R10000;
510 		c->isa_level = MIPS_CPU_ISA_IV;
511 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
512 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
513 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
514 		             MIPS_CPU_LLSC;
515 		c->tlbsize = 64;
516 		break;
517 	case PRID_IMP_R12000:
518 		c->cputype = CPU_R12000;
519 		c->isa_level = MIPS_CPU_ISA_IV;
520 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
521 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
522 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
523 		             MIPS_CPU_LLSC;
524 		c->tlbsize = 64;
525 		break;
526 	case PRID_IMP_R14000:
527 		c->cputype = CPU_R14000;
528 		c->isa_level = MIPS_CPU_ISA_IV;
529 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
530 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
531 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
532 		             MIPS_CPU_LLSC;
533 		c->tlbsize = 64;
534 		break;
535 	case PRID_IMP_LOONGSON2:
536 		c->cputype = CPU_LOONGSON2;
537 		c->isa_level = MIPS_CPU_ISA_III;
538 		c->options = R4K_OPTS |
539 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
540 			     MIPS_CPU_32FPR;
541 		c->tlbsize = 64;
542 		break;
543 	}
544 }
545 
546 static char unknown_isa[] __cpuinitdata = KERN_ERR \
547 	"Unsupported ISA type, c0.config0: %d.";
548 
549 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
550 {
551 	unsigned int config0;
552 	int isa;
553 
554 	config0 = read_c0_config();
555 
556 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
557 		c->options |= MIPS_CPU_TLB;
558 	isa = (config0 & MIPS_CONF_AT) >> 13;
559 	switch (isa) {
560 	case 0:
561 		switch ((config0 & MIPS_CONF_AR) >> 10) {
562 		case 0:
563 			c->isa_level = MIPS_CPU_ISA_M32R1;
564 			break;
565 		case 1:
566 			c->isa_level = MIPS_CPU_ISA_M32R2;
567 			break;
568 		default:
569 			goto unknown;
570 		}
571 		break;
572 	case 2:
573 		switch ((config0 & MIPS_CONF_AR) >> 10) {
574 		case 0:
575 			c->isa_level = MIPS_CPU_ISA_M64R1;
576 			break;
577 		case 1:
578 			c->isa_level = MIPS_CPU_ISA_M64R2;
579 			break;
580 		default:
581 			goto unknown;
582 		}
583 		break;
584 	default:
585 		goto unknown;
586 	}
587 
588 	return config0 & MIPS_CONF_M;
589 
590 unknown:
591 	panic(unknown_isa, config0);
592 }
593 
594 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
595 {
596 	unsigned int config1;
597 
598 	config1 = read_c0_config1();
599 
600 	if (config1 & MIPS_CONF1_MD)
601 		c->ases |= MIPS_ASE_MDMX;
602 	if (config1 & MIPS_CONF1_WR)
603 		c->options |= MIPS_CPU_WATCH;
604 	if (config1 & MIPS_CONF1_CA)
605 		c->ases |= MIPS_ASE_MIPS16;
606 	if (config1 & MIPS_CONF1_EP)
607 		c->options |= MIPS_CPU_EJTAG;
608 	if (config1 & MIPS_CONF1_FP) {
609 		c->options |= MIPS_CPU_FPU;
610 		c->options |= MIPS_CPU_32FPR;
611 	}
612 	if (cpu_has_tlb)
613 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
614 
615 	return config1 & MIPS_CONF_M;
616 }
617 
618 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
619 {
620 	unsigned int config2;
621 
622 	config2 = read_c0_config2();
623 
624 	if (config2 & MIPS_CONF2_SL)
625 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
626 
627 	return config2 & MIPS_CONF_M;
628 }
629 
630 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
631 {
632 	unsigned int config3;
633 
634 	config3 = read_c0_config3();
635 
636 	if (config3 & MIPS_CONF3_SM)
637 		c->ases |= MIPS_ASE_SMARTMIPS;
638 	if (config3 & MIPS_CONF3_DSP)
639 		c->ases |= MIPS_ASE_DSP;
640 	if (config3 & MIPS_CONF3_VINT)
641 		c->options |= MIPS_CPU_VINT;
642 	if (config3 & MIPS_CONF3_VEIC)
643 		c->options |= MIPS_CPU_VEIC;
644 	if (config3 & MIPS_CONF3_MT)
645 	        c->ases |= MIPS_ASE_MIPSMT;
646 	if (config3 & MIPS_CONF3_ULRI)
647 		c->options |= MIPS_CPU_ULRI;
648 
649 	return config3 & MIPS_CONF_M;
650 }
651 
652 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
653 {
654 	/* MIPS32 or MIPS64 compliant CPU.  */
655 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
656 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
657 
658 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
659 
660 	/* Read Config registers.  */
661 	if (!decode_config0(c))
662 		return;			/* actually worth a panic() */
663 	if (!decode_config1(c))
664 		return;
665 	if (!decode_config2(c))
666 		return;
667 	if (!decode_config3(c))
668 		return;
669 }
670 
671 #ifdef CONFIG_CPU_MIPSR2
672 extern void spram_config(void);
673 #else
674 static inline void spram_config(void) {}
675 #endif
676 
677 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
678 {
679 	decode_configs(c);
680 	switch (c->processor_id & 0xff00) {
681 	case PRID_IMP_4KC:
682 		c->cputype = CPU_4KC;
683 		break;
684 	case PRID_IMP_4KEC:
685 		c->cputype = CPU_4KEC;
686 		break;
687 	case PRID_IMP_4KECR2:
688 		c->cputype = CPU_4KEC;
689 		break;
690 	case PRID_IMP_4KSC:
691 	case PRID_IMP_4KSD:
692 		c->cputype = CPU_4KSC;
693 		break;
694 	case PRID_IMP_5KC:
695 		c->cputype = CPU_5KC;
696 		break;
697 	case PRID_IMP_20KC:
698 		c->cputype = CPU_20KC;
699 		break;
700 	case PRID_IMP_24K:
701 	case PRID_IMP_24KE:
702 		c->cputype = CPU_24K;
703 		break;
704 	case PRID_IMP_25KF:
705 		c->cputype = CPU_25KF;
706 		break;
707 	case PRID_IMP_34K:
708 		c->cputype = CPU_34K;
709 		break;
710 	case PRID_IMP_74K:
711 		c->cputype = CPU_74K;
712 		break;
713 	case PRID_IMP_1004K:
714 		c->cputype = CPU_1004K;
715 		break;
716 	}
717 
718 	spram_config();
719 }
720 
721 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
722 {
723 	decode_configs(c);
724 	switch (c->processor_id & 0xff00) {
725 	case PRID_IMP_AU1_REV1:
726 	case PRID_IMP_AU1_REV2:
727 		switch ((c->processor_id >> 24) & 0xff) {
728 		case 0:
729 			c->cputype = CPU_AU1000;
730 			break;
731 		case 1:
732 			c->cputype = CPU_AU1500;
733 			break;
734 		case 2:
735 			c->cputype = CPU_AU1100;
736 			break;
737 		case 3:
738 			c->cputype = CPU_AU1550;
739 			break;
740 		case 4:
741 			c->cputype = CPU_AU1200;
742 			if (2 == (c->processor_id & 0xff))
743 				c->cputype = CPU_AU1250;
744 			break;
745 		case 5:
746 			c->cputype = CPU_AU1210;
747 			break;
748 		default:
749 			panic("Unknown Au Core!");
750 			break;
751 		}
752 		break;
753 	}
754 }
755 
756 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
757 {
758 	decode_configs(c);
759 
760 	switch (c->processor_id & 0xff00) {
761 	case PRID_IMP_SB1:
762 		c->cputype = CPU_SB1;
763 		/* FPU in pass1 is known to have issues. */
764 		if ((c->processor_id & 0xff) < 0x02)
765 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
766 		break;
767 	case PRID_IMP_SB1A:
768 		c->cputype = CPU_SB1A;
769 		break;
770 	}
771 }
772 
773 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
774 {
775 	decode_configs(c);
776 	switch (c->processor_id & 0xff00) {
777 	case PRID_IMP_SR71000:
778 		c->cputype = CPU_SR71000;
779 		c->scache.ways = 8;
780 		c->tlbsize = 64;
781 		break;
782 	}
783 }
784 
785 static inline void cpu_probe_nxp(struct cpuinfo_mips *c)
786 {
787 	decode_configs(c);
788 	switch (c->processor_id & 0xff00) {
789 	case PRID_IMP_PR4450:
790 		c->cputype = CPU_PR4450;
791 		c->isa_level = MIPS_CPU_ISA_M32R1;
792 		break;
793 	default:
794 		panic("Unknown NXP Core!"); /* REVISIT: die? */
795 		break;
796 	}
797 }
798 
799 
800 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c)
801 {
802 	decode_configs(c);
803 	switch (c->processor_id & 0xff00) {
804 	case PRID_IMP_BCM3302:
805 		c->cputype = CPU_BCM3302;
806 		break;
807 	case PRID_IMP_BCM4710:
808 		c->cputype = CPU_BCM4710;
809 		break;
810 	default:
811 		c->cputype = CPU_UNKNOWN;
812 		break;
813 	}
814 }
815 
816 const char *__cpu_name[NR_CPUS];
817 
818 /*
819  * Name a CPU
820  */
821 static __cpuinit const char *cpu_to_name(struct cpuinfo_mips *c)
822 {
823 	const char *name = NULL;
824 
825 	switch (c->cputype) {
826 	case CPU_UNKNOWN:	name = "unknown"; break;
827 	case CPU_R2000:		name = "R2000"; break;
828 	case CPU_R3000:		name = "R3000"; break;
829 	case CPU_R3000A:	name = "R3000A"; break;
830 	case CPU_R3041:		name = "R3041"; break;
831 	case CPU_R3051:		name = "R3051"; break;
832 	case CPU_R3052:		name = "R3052"; break;
833 	case CPU_R3081:		name = "R3081"; break;
834 	case CPU_R3081E:	name = "R3081E"; break;
835 	case CPU_R4000PC:	name = "R4000PC"; break;
836 	case CPU_R4000SC:	name = "R4000SC"; break;
837 	case CPU_R4000MC:	name = "R4000MC"; break;
838 	case CPU_R4200:		name = "R4200"; break;
839 	case CPU_R4400PC:	name = "R4400PC"; break;
840 	case CPU_R4400SC:	name = "R4400SC"; break;
841 	case CPU_R4400MC:	name = "R4400MC"; break;
842 	case CPU_R4600:		name = "R4600"; break;
843 	case CPU_R6000:		name = "R6000"; break;
844 	case CPU_R6000A:	name = "R6000A"; break;
845 	case CPU_R8000:		name = "R8000"; break;
846 	case CPU_R10000:	name = "R10000"; break;
847 	case CPU_R12000:	name = "R12000"; break;
848 	case CPU_R14000:	name = "R14000"; break;
849 	case CPU_R4300:		name = "R4300"; break;
850 	case CPU_R4650:		name = "R4650"; break;
851 	case CPU_R4700:		name = "R4700"; break;
852 	case CPU_R5000:		name = "R5000"; break;
853 	case CPU_R5000A:	name = "R5000A"; break;
854 	case CPU_R4640:		name = "R4640"; break;
855 	case CPU_NEVADA:	name = "Nevada"; break;
856 	case CPU_RM7000:	name = "RM7000"; break;
857 	case CPU_RM9000:	name = "RM9000"; break;
858 	case CPU_R5432:		name = "R5432"; break;
859 	case CPU_4KC:		name = "MIPS 4Kc"; break;
860 	case CPU_5KC:		name = "MIPS 5Kc"; break;
861 	case CPU_R4310:		name = "R4310"; break;
862 	case CPU_SB1:		name = "SiByte SB1"; break;
863 	case CPU_SB1A:		name = "SiByte SB1A"; break;
864 	case CPU_TX3912:	name = "TX3912"; break;
865 	case CPU_TX3922:	name = "TX3922"; break;
866 	case CPU_TX3927:	name = "TX3927"; break;
867 	case CPU_AU1000:	name = "Au1000"; break;
868 	case CPU_AU1500:	name = "Au1500"; break;
869 	case CPU_AU1100:	name = "Au1100"; break;
870 	case CPU_AU1550:	name = "Au1550"; break;
871 	case CPU_AU1200:	name = "Au1200"; break;
872 	case CPU_AU1210:	name = "Au1210"; break;
873 	case CPU_AU1250:	name = "Au1250"; break;
874 	case CPU_4KEC:		name = "MIPS 4KEc"; break;
875 	case CPU_4KSC:		name = "MIPS 4KSc"; break;
876 	case CPU_VR41XX:	name = "NEC Vr41xx"; break;
877 	case CPU_R5500:		name = "R5500"; break;
878 	case CPU_TX49XX:	name = "TX49xx"; break;
879 	case CPU_20KC:		name = "MIPS 20Kc"; break;
880 	case CPU_24K:		name = "MIPS 24K"; break;
881 	case CPU_25KF:		name = "MIPS 25Kf"; break;
882 	case CPU_34K:		name = "MIPS 34K"; break;
883 	case CPU_1004K:		name = "MIPS 1004K"; break;
884 	case CPU_74K:		name = "MIPS 74K"; break;
885 	case CPU_VR4111:	name = "NEC VR4111"; break;
886 	case CPU_VR4121:	name = "NEC VR4121"; break;
887 	case CPU_VR4122:	name = "NEC VR4122"; break;
888 	case CPU_VR4131:	name = "NEC VR4131"; break;
889 	case CPU_VR4133:	name = "NEC VR4133"; break;
890 	case CPU_VR4181:	name = "NEC VR4181"; break;
891 	case CPU_VR4181A:	name = "NEC VR4181A"; break;
892 	case CPU_SR71000:	name = "Sandcraft SR71000"; break;
893 	case CPU_BCM3302:	name = "Broadcom BCM3302"; break;
894 	case CPU_BCM4710:	name = "Broadcom BCM4710"; break;
895 	case CPU_PR4450:	name = "Philips PR4450"; break;
896 	case CPU_LOONGSON2:	name = "ICT Loongson-2"; break;
897 	default:
898 		BUG();
899 	}
900 
901 	return name;
902 }
903 
904 __cpuinit void cpu_probe(void)
905 {
906 	struct cpuinfo_mips *c = &current_cpu_data;
907 	unsigned int cpu = smp_processor_id();
908 
909 	c->processor_id	= PRID_IMP_UNKNOWN;
910 	c->fpu_id	= FPIR_IMP_NONE;
911 	c->cputype	= CPU_UNKNOWN;
912 
913 	c->processor_id = read_c0_prid();
914 	switch (c->processor_id & 0xff0000) {
915 	case PRID_COMP_LEGACY:
916 		cpu_probe_legacy(c);
917 		break;
918 	case PRID_COMP_MIPS:
919 		cpu_probe_mips(c);
920 		break;
921 	case PRID_COMP_ALCHEMY:
922 		cpu_probe_alchemy(c);
923 		break;
924 	case PRID_COMP_SIBYTE:
925 		cpu_probe_sibyte(c);
926 		break;
927 	case PRID_COMP_BROADCOM:
928 		cpu_probe_broadcom(c);
929 		break;
930 	case PRID_COMP_SANDCRAFT:
931 		cpu_probe_sandcraft(c);
932 		break;
933 	case PRID_COMP_NXP:
934 		cpu_probe_nxp(c);
935 		break;
936 	default:
937 		c->cputype = CPU_UNKNOWN;
938 	}
939 
940 	/*
941 	 * Platform code can force the cpu type to optimize code
942 	 * generation. In that case be sure the cpu type is correctly
943 	 * manually setup otherwise it could trigger some nasty bugs.
944 	 */
945 	BUG_ON(current_cpu_type() != c->cputype);
946 
947 	if (c->options & MIPS_CPU_FPU) {
948 		c->fpu_id = cpu_get_fpu_id();
949 
950 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
951 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
952 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
953 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
954 			if (c->fpu_id & MIPS_FPIR_3D)
955 				c->ases |= MIPS_ASE_MIPS3D;
956 		}
957 	}
958 
959 	__cpu_name[cpu] = cpu_to_name(c);
960 
961 	if (cpu_has_mips_r2)
962 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
963 	else
964 		c->srsets = 1;
965 }
966 
967 __cpuinit void cpu_report(void)
968 {
969 	struct cpuinfo_mips *c = &current_cpu_data;
970 
971 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
972 	       c->processor_id, cpu_name_string());
973 	if (c->options & MIPS_CPU_FPU)
974 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
975 }
976