xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 643d1f7f)
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 	case CPU_BCM3302:
163 		cpu_wait = r4k_wait;
164 		break;
165 
166 	case CPU_RM7000:
167 		cpu_wait = rm7k_wait_irqoff;
168 		break;
169 
170 	case CPU_24K:
171 	case CPU_34K:
172 		cpu_wait = r4k_wait;
173 		if (read_c0_config7() & MIPS_CONF7_WII)
174 			cpu_wait = r4k_wait_irqoff;
175 		break;
176 
177 	case CPU_74K:
178 		cpu_wait = r4k_wait;
179 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
180 			cpu_wait = r4k_wait_irqoff;
181 		break;
182 
183 	case CPU_TX49XX:
184 		cpu_wait = r4k_wait_irqoff;
185 		break;
186 	case CPU_AU1000:
187 	case CPU_AU1100:
188 	case CPU_AU1500:
189 	case CPU_AU1550:
190 	case CPU_AU1200:
191 	case CPU_AU1210:
192 	case CPU_AU1250:
193 		if (allow_au1k_wait)
194 			cpu_wait = au1k_wait;
195 		break;
196 	case CPU_20KC:
197 		/*
198 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
199 		 * WAIT on Rev2.0 and Rev3.0 has E16.
200 		 * Rev3.1 WAIT is nop, why bother
201 		 */
202 		if ((c->processor_id & 0xff) <= 0x64)
203 			break;
204 
205 		/*
206 		 * Another rev is incremeting c0_count at a reduced clock
207 		 * rate while in WAIT mode.  So we basically have the choice
208 		 * between using the cp0 timer as clocksource or avoiding
209 		 * the WAIT instruction.  Until more details are known,
210 		 * disable the use of WAIT for 20Kc entirely.
211 		   cpu_wait = r4k_wait;
212 		 */
213 		break;
214 	case CPU_RM9000:
215 		if ((c->processor_id & 0x00ff) >= 0x40)
216 			cpu_wait = r4k_wait;
217 		break;
218 	default:
219 		break;
220 	}
221 }
222 
223 static inline void check_errata(void)
224 {
225 	struct cpuinfo_mips *c = &current_cpu_data;
226 
227 	switch (c->cputype) {
228 	case CPU_34K:
229 		/*
230 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
231 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
232 		 * making use of VPE1 will be responsable for that VPE.
233 		 */
234 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
235 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
236 		break;
237 	default:
238 		break;
239 	}
240 }
241 
242 void __init check_bugs32(void)
243 {
244 	check_wait();
245 	check_errata();
246 }
247 
248 /*
249  * Probe whether cpu has config register by trying to play with
250  * alternate cache bit and see whether it matters.
251  * It's used by cpu_probe to distinguish between R3000A and R3081.
252  */
253 static inline int cpu_has_confreg(void)
254 {
255 #ifdef CONFIG_CPU_R3000
256 	extern unsigned long r3k_cache_size(unsigned long);
257 	unsigned long size1, size2;
258 	unsigned long cfg = read_c0_conf();
259 
260 	size1 = r3k_cache_size(ST0_ISC);
261 	write_c0_conf(cfg ^ R30XX_CONF_AC);
262 	size2 = r3k_cache_size(ST0_ISC);
263 	write_c0_conf(cfg);
264 	return size1 != size2;
265 #else
266 	return 0;
267 #endif
268 }
269 
270 /*
271  * Get the FPU Implementation/Revision.
272  */
273 static inline unsigned long cpu_get_fpu_id(void)
274 {
275 	unsigned long tmp, fpu_id;
276 
277 	tmp = read_c0_status();
278 	__enable_fpu();
279 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
280 	write_c0_status(tmp);
281 	return fpu_id;
282 }
283 
284 /*
285  * Check the CPU has an FPU the official way.
286  */
287 static inline int __cpu_has_fpu(void)
288 {
289 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
290 }
291 
292 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
293 		| MIPS_CPU_COUNTER)
294 
295 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
296 {
297 	switch (c->processor_id & 0xff00) {
298 	case PRID_IMP_R2000:
299 		c->cputype = CPU_R2000;
300 		c->isa_level = MIPS_CPU_ISA_I;
301 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
302 		             MIPS_CPU_NOFPUEX;
303 		if (__cpu_has_fpu())
304 			c->options |= MIPS_CPU_FPU;
305 		c->tlbsize = 64;
306 		break;
307 	case PRID_IMP_R3000:
308 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
309 			if (cpu_has_confreg())
310 				c->cputype = CPU_R3081E;
311 			else
312 				c->cputype = CPU_R3000A;
313 		else
314 			c->cputype = CPU_R3000;
315 		c->isa_level = MIPS_CPU_ISA_I;
316 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
317 		             MIPS_CPU_NOFPUEX;
318 		if (__cpu_has_fpu())
319 			c->options |= MIPS_CPU_FPU;
320 		c->tlbsize = 64;
321 		break;
322 	case PRID_IMP_R4000:
323 		if (read_c0_config() & CONF_SC) {
324 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
325 				c->cputype = CPU_R4400PC;
326 			else
327 				c->cputype = CPU_R4000PC;
328 		} else {
329 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
330 				c->cputype = CPU_R4400SC;
331 			else
332 				c->cputype = CPU_R4000SC;
333 		}
334 
335 		c->isa_level = MIPS_CPU_ISA_III;
336 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
337 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
338 		             MIPS_CPU_LLSC;
339 		c->tlbsize = 48;
340 		break;
341 	case PRID_IMP_VR41XX:
342 		switch (c->processor_id & 0xf0) {
343 		case PRID_REV_VR4111:
344 			c->cputype = CPU_VR4111;
345 			break;
346 		case PRID_REV_VR4121:
347 			c->cputype = CPU_VR4121;
348 			break;
349 		case PRID_REV_VR4122:
350 			if ((c->processor_id & 0xf) < 0x3)
351 				c->cputype = CPU_VR4122;
352 			else
353 				c->cputype = CPU_VR4181A;
354 			break;
355 		case PRID_REV_VR4130:
356 			if ((c->processor_id & 0xf) < 0x4)
357 				c->cputype = CPU_VR4131;
358 			else
359 				c->cputype = CPU_VR4133;
360 			break;
361 		default:
362 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
363 			c->cputype = CPU_VR41XX;
364 			break;
365 		}
366 		c->isa_level = MIPS_CPU_ISA_III;
367 		c->options = R4K_OPTS;
368 		c->tlbsize = 32;
369 		break;
370 	case PRID_IMP_R4300:
371 		c->cputype = CPU_R4300;
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 = 32;
376 		break;
377 	case PRID_IMP_R4600:
378 		c->cputype = CPU_R4600;
379 		c->isa_level = MIPS_CPU_ISA_III;
380 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
381 			     MIPS_CPU_LLSC;
382 		c->tlbsize = 48;
383 		break;
384 	#if 0
385  	case PRID_IMP_R4650:
386 		/*
387 		 * This processor doesn't have an MMU, so it's not
388 		 * "real easy" to run Linux on it. It is left purely
389 		 * for documentation.  Commented out because it shares
390 		 * it's c0_prid id number with the TX3900.
391 		 */
392 		c->cputype = CPU_R4650;
393 	 	c->isa_level = MIPS_CPU_ISA_III;
394 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
395 	        c->tlbsize = 48;
396 		break;
397 	#endif
398 	case PRID_IMP_TX39:
399 		c->isa_level = MIPS_CPU_ISA_I;
400 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
401 
402 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
403 			c->cputype = CPU_TX3927;
404 			c->tlbsize = 64;
405 		} else {
406 			switch (c->processor_id & 0xff) {
407 			case PRID_REV_TX3912:
408 				c->cputype = CPU_TX3912;
409 				c->tlbsize = 32;
410 				break;
411 			case PRID_REV_TX3922:
412 				c->cputype = CPU_TX3922;
413 				c->tlbsize = 64;
414 				break;
415 			default:
416 				c->cputype = CPU_UNKNOWN;
417 				break;
418 			}
419 		}
420 		break;
421 	case PRID_IMP_R4700:
422 		c->cputype = CPU_R4700;
423 		c->isa_level = MIPS_CPU_ISA_III;
424 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
425 		             MIPS_CPU_LLSC;
426 		c->tlbsize = 48;
427 		break;
428 	case PRID_IMP_TX49:
429 		c->cputype = CPU_TX49XX;
430 		c->isa_level = MIPS_CPU_ISA_III;
431 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
432 		if (!(c->processor_id & 0x08))
433 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
434 		c->tlbsize = 48;
435 		break;
436 	case PRID_IMP_R5000:
437 		c->cputype = CPU_R5000;
438 		c->isa_level = MIPS_CPU_ISA_IV;
439 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
440 		             MIPS_CPU_LLSC;
441 		c->tlbsize = 48;
442 		break;
443 	case PRID_IMP_R5432:
444 		c->cputype = CPU_R5432;
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_R5500:
451 		c->cputype = CPU_R5500;
452 		c->isa_level = MIPS_CPU_ISA_IV;
453 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
454 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
455 		c->tlbsize = 48;
456 		break;
457 	case PRID_IMP_NEVADA:
458 		c->cputype = CPU_NEVADA;
459 		c->isa_level = MIPS_CPU_ISA_IV;
460 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
461 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
462 		c->tlbsize = 48;
463 		break;
464 	case PRID_IMP_R6000:
465 		c->cputype = CPU_R6000;
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_R6000A:
472 		c->cputype = CPU_R6000A;
473 		c->isa_level = MIPS_CPU_ISA_II;
474 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
475 		             MIPS_CPU_LLSC;
476 		c->tlbsize = 32;
477 		break;
478 	case PRID_IMP_RM7000:
479 		c->cputype = CPU_RM7000;
480 		c->isa_level = MIPS_CPU_ISA_IV;
481 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
482 		             MIPS_CPU_LLSC;
483 		/*
484 		 * Undocumented RM7000:  Bit 29 in the info register of
485 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
486 		 * entries.
487 		 *
488 		 * 29      1 =>    64 entry JTLB
489 		 *         0 =>    48 entry JTLB
490 		 */
491 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
492 		break;
493 	case PRID_IMP_RM9000:
494 		c->cputype = CPU_RM9000;
495 		c->isa_level = MIPS_CPU_ISA_IV;
496 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
497 		             MIPS_CPU_LLSC;
498 		/*
499 		 * Bit 29 in the info register of the RM9000
500 		 * indicates if the TLB has 48 or 64 entries.
501 		 *
502 		 * 29      1 =>    64 entry JTLB
503 		 *         0 =>    48 entry JTLB
504 		 */
505 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
506 		break;
507 	case PRID_IMP_R8000:
508 		c->cputype = CPU_R8000;
509 		c->isa_level = MIPS_CPU_ISA_IV;
510 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
511 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
512 		             MIPS_CPU_LLSC;
513 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
514 		break;
515 	case PRID_IMP_R10000:
516 		c->cputype = CPU_R10000;
517 		c->isa_level = MIPS_CPU_ISA_IV;
518 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
519 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
520 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
521 		             MIPS_CPU_LLSC;
522 		c->tlbsize = 64;
523 		break;
524 	case PRID_IMP_R12000:
525 		c->cputype = CPU_R12000;
526 		c->isa_level = MIPS_CPU_ISA_IV;
527 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
528 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
529 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
530 		             MIPS_CPU_LLSC;
531 		c->tlbsize = 64;
532 		break;
533 	case PRID_IMP_R14000:
534 		c->cputype = CPU_R14000;
535 		c->isa_level = MIPS_CPU_ISA_IV;
536 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
537 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
538 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
539 		             MIPS_CPU_LLSC;
540 		c->tlbsize = 64;
541 		break;
542 	case PRID_IMP_LOONGSON2:
543 		c->cputype = CPU_LOONGSON2;
544 		c->isa_level = MIPS_CPU_ISA_III;
545 		c->options = R4K_OPTS |
546 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
547 			     MIPS_CPU_32FPR;
548 		c->tlbsize = 64;
549 		break;
550 	}
551 }
552 
553 static char unknown_isa[] __initdata = KERN_ERR \
554 	"Unsupported ISA type, c0.config0: %d.";
555 
556 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
557 {
558 	unsigned int config0;
559 	int isa;
560 
561 	config0 = read_c0_config();
562 
563 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
564 		c->options |= MIPS_CPU_TLB;
565 	isa = (config0 & MIPS_CONF_AT) >> 13;
566 	switch (isa) {
567 	case 0:
568 		switch ((config0 & MIPS_CONF_AR) >> 10) {
569 		case 0:
570 			c->isa_level = MIPS_CPU_ISA_M32R1;
571 			break;
572 		case 1:
573 			c->isa_level = MIPS_CPU_ISA_M32R2;
574 			break;
575 		default:
576 			goto unknown;
577 		}
578 		break;
579 	case 2:
580 		switch ((config0 & MIPS_CONF_AR) >> 10) {
581 		case 0:
582 			c->isa_level = MIPS_CPU_ISA_M64R1;
583 			break;
584 		case 1:
585 			c->isa_level = MIPS_CPU_ISA_M64R2;
586 			break;
587 		default:
588 			goto unknown;
589 		}
590 		break;
591 	default:
592 		goto unknown;
593 	}
594 
595 	return config0 & MIPS_CONF_M;
596 
597 unknown:
598 	panic(unknown_isa, config0);
599 }
600 
601 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
602 {
603 	unsigned int config1;
604 
605 	config1 = read_c0_config1();
606 
607 	if (config1 & MIPS_CONF1_MD)
608 		c->ases |= MIPS_ASE_MDMX;
609 	if (config1 & MIPS_CONF1_WR)
610 		c->options |= MIPS_CPU_WATCH;
611 	if (config1 & MIPS_CONF1_CA)
612 		c->ases |= MIPS_ASE_MIPS16;
613 	if (config1 & MIPS_CONF1_EP)
614 		c->options |= MIPS_CPU_EJTAG;
615 	if (config1 & MIPS_CONF1_FP) {
616 		c->options |= MIPS_CPU_FPU;
617 		c->options |= MIPS_CPU_32FPR;
618 	}
619 	if (cpu_has_tlb)
620 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
621 
622 	return config1 & MIPS_CONF_M;
623 }
624 
625 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
626 {
627 	unsigned int config2;
628 
629 	config2 = read_c0_config2();
630 
631 	if (config2 & MIPS_CONF2_SL)
632 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
633 
634 	return config2 & MIPS_CONF_M;
635 }
636 
637 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
638 {
639 	unsigned int config3;
640 
641 	config3 = read_c0_config3();
642 
643 	if (config3 & MIPS_CONF3_SM)
644 		c->ases |= MIPS_ASE_SMARTMIPS;
645 	if (config3 & MIPS_CONF3_DSP)
646 		c->ases |= MIPS_ASE_DSP;
647 	if (config3 & MIPS_CONF3_VINT)
648 		c->options |= MIPS_CPU_VINT;
649 	if (config3 & MIPS_CONF3_VEIC)
650 		c->options |= MIPS_CPU_VEIC;
651 	if (config3 & MIPS_CONF3_MT)
652 	        c->ases |= MIPS_ASE_MIPSMT;
653 	if (config3 & MIPS_CONF3_ULRI)
654 		c->options |= MIPS_CPU_ULRI;
655 
656 	return config3 & MIPS_CONF_M;
657 }
658 
659 static void __init decode_configs(struct cpuinfo_mips *c)
660 {
661 	/* MIPS32 or MIPS64 compliant CPU.  */
662 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
663 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
664 
665 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
666 
667 	/* Read Config registers.  */
668 	if (!decode_config0(c))
669 		return;			/* actually worth a panic() */
670 	if (!decode_config1(c))
671 		return;
672 	if (!decode_config2(c))
673 		return;
674 	if (!decode_config3(c))
675 		return;
676 }
677 
678 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
679 {
680 	decode_configs(c);
681 	switch (c->processor_id & 0xff00) {
682 	case PRID_IMP_4KC:
683 		c->cputype = CPU_4KC;
684 		break;
685 	case PRID_IMP_4KEC:
686 		c->cputype = CPU_4KEC;
687 		break;
688 	case PRID_IMP_4KECR2:
689 		c->cputype = CPU_4KEC;
690 		break;
691 	case PRID_IMP_4KSC:
692 	case PRID_IMP_4KSD:
693 		c->cputype = CPU_4KSC;
694 		break;
695 	case PRID_IMP_5KC:
696 		c->cputype = CPU_5KC;
697 		break;
698 	case PRID_IMP_20KC:
699 		c->cputype = CPU_20KC;
700 		break;
701 	case PRID_IMP_24K:
702 	case PRID_IMP_24KE:
703 		c->cputype = CPU_24K;
704 		break;
705 	case PRID_IMP_25KF:
706 		c->cputype = CPU_25KF;
707 		break;
708 	case PRID_IMP_34K:
709 		c->cputype = CPU_34K;
710 		break;
711 	case PRID_IMP_74K:
712 		c->cputype = CPU_74K;
713 		break;
714 	}
715 }
716 
717 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
718 {
719 	decode_configs(c);
720 	switch (c->processor_id & 0xff00) {
721 	case PRID_IMP_AU1_REV1:
722 	case PRID_IMP_AU1_REV2:
723 		switch ((c->processor_id >> 24) & 0xff) {
724 		case 0:
725 			c->cputype = CPU_AU1000;
726 			break;
727 		case 1:
728 			c->cputype = CPU_AU1500;
729 			break;
730 		case 2:
731 			c->cputype = CPU_AU1100;
732 			break;
733 		case 3:
734 			c->cputype = CPU_AU1550;
735 			break;
736 		case 4:
737 			c->cputype = CPU_AU1200;
738 			if (2 == (c->processor_id & 0xff))
739 				c->cputype = CPU_AU1250;
740 			break;
741 		case 5:
742 			c->cputype = CPU_AU1210;
743 			break;
744 		default:
745 			panic("Unknown Au Core!");
746 			break;
747 		}
748 		break;
749 	}
750 }
751 
752 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
753 {
754 	decode_configs(c);
755 
756 	switch (c->processor_id & 0xff00) {
757 	case PRID_IMP_SB1:
758 		c->cputype = CPU_SB1;
759 		/* FPU in pass1 is known to have issues. */
760 		if ((c->processor_id & 0xff) < 0x02)
761 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
762 		break;
763 	case PRID_IMP_SB1A:
764 		c->cputype = CPU_SB1A;
765 		break;
766 	}
767 }
768 
769 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
770 {
771 	decode_configs(c);
772 	switch (c->processor_id & 0xff00) {
773 	case PRID_IMP_SR71000:
774 		c->cputype = CPU_SR71000;
775 		c->scache.ways = 8;
776 		c->tlbsize = 64;
777 		break;
778 	}
779 }
780 
781 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
782 {
783 	decode_configs(c);
784 	switch (c->processor_id & 0xff00) {
785 	case PRID_IMP_PR4450:
786 		c->cputype = CPU_PR4450;
787 		c->isa_level = MIPS_CPU_ISA_M32R1;
788 		break;
789 	default:
790 		panic("Unknown Philips Core!"); /* REVISIT: die? */
791 		break;
792 	}
793 }
794 
795 
796 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c)
797 {
798 	decode_configs(c);
799 	switch (c->processor_id & 0xff00) {
800 	case PRID_IMP_BCM3302:
801 		c->cputype = CPU_BCM3302;
802 		break;
803 	case PRID_IMP_BCM4710:
804 		c->cputype = CPU_BCM4710;
805 		break;
806 	default:
807 		c->cputype = CPU_UNKNOWN;
808 		break;
809 	}
810 }
811 
812 const char *__cpu_name[NR_CPUS];
813 
814 /*
815  * Name a CPU
816  */
817 static __init const char *cpu_to_name(struct cpuinfo_mips *c)
818 {
819 	const char *name = NULL;
820 
821 	switch (c->cputype) {
822 	case CPU_UNKNOWN:	name = "unknown"; break;
823 	case CPU_R2000:		name = "R2000"; break;
824 	case CPU_R3000:		name = "R3000"; break;
825 	case CPU_R3000A:	name = "R3000A"; break;
826 	case CPU_R3041:		name = "R3041"; break;
827 	case CPU_R3051:		name = "R3051"; break;
828 	case CPU_R3052:		name = "R3052"; break;
829 	case CPU_R3081:		name = "R3081"; break;
830 	case CPU_R3081E:	name = "R3081E"; break;
831 	case CPU_R4000PC:	name = "R4000PC"; break;
832 	case CPU_R4000SC:	name = "R4000SC"; break;
833 	case CPU_R4000MC:	name = "R4000MC"; break;
834 	case CPU_R4200:		name = "R4200"; break;
835 	case CPU_R4400PC:	name = "R4400PC"; break;
836 	case CPU_R4400SC:	name = "R4400SC"; break;
837 	case CPU_R4400MC:	name = "R4400MC"; break;
838 	case CPU_R4600:		name = "R4600"; break;
839 	case CPU_R6000:		name = "R6000"; break;
840 	case CPU_R6000A:	name = "R6000A"; break;
841 	case CPU_R8000:		name = "R8000"; break;
842 	case CPU_R10000:	name = "R10000"; break;
843 	case CPU_R12000:	name = "R12000"; break;
844 	case CPU_R14000:	name = "R14000"; break;
845 	case CPU_R4300:		name = "R4300"; break;
846 	case CPU_R4650:		name = "R4650"; break;
847 	case CPU_R4700:		name = "R4700"; break;
848 	case CPU_R5000:		name = "R5000"; break;
849 	case CPU_R5000A:	name = "R5000A"; break;
850 	case CPU_R4640:		name = "R4640"; break;
851 	case CPU_NEVADA:	name = "Nevada"; break;
852 	case CPU_RM7000:	name = "RM7000"; break;
853 	case CPU_RM9000:	name = "RM9000"; break;
854 	case CPU_R5432:		name = "R5432"; break;
855 	case CPU_4KC:		name = "MIPS 4Kc"; break;
856 	case CPU_5KC:		name = "MIPS 5Kc"; break;
857 	case CPU_R4310:		name = "R4310"; break;
858 	case CPU_SB1:		name = "SiByte SB1"; break;
859 	case CPU_SB1A:		name = "SiByte SB1A"; break;
860 	case CPU_TX3912:	name = "TX3912"; break;
861 	case CPU_TX3922:	name = "TX3922"; break;
862 	case CPU_TX3927:	name = "TX3927"; break;
863 	case CPU_AU1000:	name = "Au1000"; break;
864 	case CPU_AU1500:	name = "Au1500"; break;
865 	case CPU_AU1100:	name = "Au1100"; break;
866 	case CPU_AU1550:	name = "Au1550"; break;
867 	case CPU_AU1200:	name = "Au1200"; break;
868 	case CPU_AU1210:	name = "Au1210"; break;
869 	case CPU_AU1250:	name = "Au1250"; break;
870 	case CPU_4KEC:		name = "MIPS 4KEc"; break;
871 	case CPU_4KSC:		name = "MIPS 4KSc"; break;
872 	case CPU_VR41XX:	name = "NEC Vr41xx"; break;
873 	case CPU_R5500:		name = "R5500"; break;
874 	case CPU_TX49XX:	name = "TX49xx"; break;
875 	case CPU_20KC:		name = "MIPS 20Kc"; break;
876 	case CPU_24K:		name = "MIPS 24K"; break;
877 	case CPU_25KF:		name = "MIPS 25Kf"; break;
878 	case CPU_34K:		name = "MIPS 34K"; break;
879 	case CPU_74K:		name = "MIPS 74K"; break;
880 	case CPU_VR4111:	name = "NEC VR4111"; break;
881 	case CPU_VR4121:	name = "NEC VR4121"; break;
882 	case CPU_VR4122:	name = "NEC VR4122"; break;
883 	case CPU_VR4131:	name = "NEC VR4131"; break;
884 	case CPU_VR4133:	name = "NEC VR4133"; break;
885 	case CPU_VR4181:	name = "NEC VR4181"; break;
886 	case CPU_VR4181A:	name = "NEC VR4181A"; break;
887 	case CPU_SR71000:	name = "Sandcraft SR71000"; break;
888 	case CPU_BCM3302:	name = "Broadcom BCM3302"; break;
889 	case CPU_BCM4710:	name = "Broadcom BCM4710"; break;
890 	case CPU_PR4450:	name = "Philips PR4450"; break;
891 	case CPU_LOONGSON2:	name = "ICT Loongson-2"; break;
892 	default:
893 		BUG();
894 	}
895 
896 	return name;
897 }
898 
899 __init void cpu_probe(void)
900 {
901 	struct cpuinfo_mips *c = &current_cpu_data;
902 	unsigned int cpu = smp_processor_id();
903 
904 	c->processor_id	= PRID_IMP_UNKNOWN;
905 	c->fpu_id	= FPIR_IMP_NONE;
906 	c->cputype	= CPU_UNKNOWN;
907 
908 	c->processor_id = read_c0_prid();
909 	switch (c->processor_id & 0xff0000) {
910 	case PRID_COMP_LEGACY:
911 		cpu_probe_legacy(c);
912 		break;
913 	case PRID_COMP_MIPS:
914 		cpu_probe_mips(c);
915 		break;
916 	case PRID_COMP_ALCHEMY:
917 		cpu_probe_alchemy(c);
918 		break;
919 	case PRID_COMP_SIBYTE:
920 		cpu_probe_sibyte(c);
921 		break;
922 	case PRID_COMP_BROADCOM:
923 		cpu_probe_broadcom(c);
924 		break;
925 	case PRID_COMP_SANDCRAFT:
926 		cpu_probe_sandcraft(c);
927 		break;
928  	case PRID_COMP_PHILIPS:
929 		cpu_probe_philips(c);
930 		break;
931 	default:
932 		c->cputype = CPU_UNKNOWN;
933 	}
934 
935 	/*
936 	 * Platform code can force the cpu type to optimize code
937 	 * generation. In that case be sure the cpu type is correctly
938 	 * manually setup otherwise it could trigger some nasty bugs.
939 	 */
940 	BUG_ON(current_cpu_type() != c->cputype);
941 
942 	if (c->options & MIPS_CPU_FPU) {
943 		c->fpu_id = cpu_get_fpu_id();
944 
945 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
946 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
947 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
948 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
949 			if (c->fpu_id & MIPS_FPIR_3D)
950 				c->ases |= MIPS_ASE_MIPS3D;
951 		}
952 	}
953 
954 	__cpu_name[cpu] = cpu_to_name(c);
955 
956 	if (cpu_has_mips_r2)
957 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
958 	else
959 		c->srsets = 1;
960 }
961 
962 __init void cpu_report(void)
963 {
964 	struct cpuinfo_mips *c = &current_cpu_data;
965 
966 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
967 	       c->processor_id, cpu_name_string());
968 	if (c->options & MIPS_CPU_FPU)
969 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
970 }
971