xref: /linux/arch/mips/kernel/cpu-probe.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
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/smp.h>
18 #include <linux/stddef.h>
19 #include <linux/module.h>
20 
21 #include <asm/bugs.h>
22 #include <asm/cpu.h>
23 #include <asm/fpu.h>
24 #include <asm/mipsregs.h>
25 #include <asm/system.h>
26 #include <asm/watch.h>
27 #include <asm/spram.h>
28 /*
29  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
30  * the implementation of the "wait" feature differs between CPU families. This
31  * points to the function that implements CPU specific wait.
32  * The wait instruction stops the pipeline and reduces the power consumption of
33  * the CPU very much.
34  */
35 void (*cpu_wait)(void);
36 EXPORT_SYMBOL(cpu_wait);
37 
38 static void r3081_wait(void)
39 {
40 	unsigned long cfg = read_c0_conf();
41 	write_c0_conf(cfg | R30XX_CONF_HALT);
42 }
43 
44 static void r39xx_wait(void)
45 {
46 	local_irq_disable();
47 	if (!need_resched())
48 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
49 	local_irq_enable();
50 }
51 
52 extern void r4k_wait(void);
53 
54 /*
55  * This variant is preferable as it allows testing need_resched and going to
56  * sleep depending on the outcome atomically.  Unfortunately the "It is
57  * implementation-dependent whether the pipeline restarts when a non-enabled
58  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
59  * using this version a gamble.
60  */
61 void r4k_wait_irqoff(void)
62 {
63 	local_irq_disable();
64 	if (!need_resched())
65 		__asm__("	.set	push		\n"
66 			"	.set	mips3		\n"
67 			"	wait			\n"
68 			"	.set	pop		\n");
69 	local_irq_enable();
70 	__asm__(" 	.globl __pastwait	\n"
71 		"__pastwait:			\n");
72 	return;
73 }
74 
75 /*
76  * The RM7000 variant has to handle erratum 38.  The workaround is to not
77  * have any pending stores when the WAIT instruction is executed.
78  */
79 static void rm7k_wait_irqoff(void)
80 {
81 	local_irq_disable();
82 	if (!need_resched())
83 		__asm__(
84 		"	.set	push					\n"
85 		"	.set	mips3					\n"
86 		"	.set	noat					\n"
87 		"	mfc0	$1, $12					\n"
88 		"	sync						\n"
89 		"	mtc0	$1, $12		# stalls until W stage	\n"
90 		"	wait						\n"
91 		"	mtc0	$1, $12		# stalls until W stage	\n"
92 		"	.set	pop					\n");
93 	local_irq_enable();
94 }
95 
96 /*
97  * The Au1xxx wait is available only if using 32khz counter or
98  * external timer source, but specifically not CP0 Counter.
99  * alchemy/common/time.c may override cpu_wait!
100  */
101 static void au1k_wait(void)
102 {
103 	__asm__("	.set	mips3			\n"
104 		"	cache	0x14, 0(%0)		\n"
105 		"	cache	0x14, 32(%0)		\n"
106 		"	sync				\n"
107 		"	nop				\n"
108 		"	wait				\n"
109 		"	nop				\n"
110 		"	nop				\n"
111 		"	nop				\n"
112 		"	nop				\n"
113 		"	.set	mips0			\n"
114 		: : "r" (au1k_wait));
115 }
116 
117 static int __initdata nowait;
118 
119 static int __init wait_disable(char *s)
120 {
121 	nowait = 1;
122 
123 	return 1;
124 }
125 
126 __setup("nowait", wait_disable);
127 
128 static int __cpuinitdata mips_fpu_disabled;
129 
130 static int __init fpu_disable(char *s)
131 {
132 	cpu_data[0].options &= ~MIPS_CPU_FPU;
133 	mips_fpu_disabled = 1;
134 
135 	return 1;
136 }
137 
138 __setup("nofpu", fpu_disable);
139 
140 int __cpuinitdata mips_dsp_disabled;
141 
142 static int __init dsp_disable(char *s)
143 {
144 	cpu_data[0].ases &= ~MIPS_ASE_DSP;
145 	mips_dsp_disabled = 1;
146 
147 	return 1;
148 }
149 
150 __setup("nodsp", dsp_disable);
151 
152 void __init check_wait(void)
153 {
154 	struct cpuinfo_mips *c = &current_cpu_data;
155 
156 	if (nowait) {
157 		printk("Wait instruction disabled.\n");
158 		return;
159 	}
160 
161 	switch (c->cputype) {
162 	case CPU_R3081:
163 	case CPU_R3081E:
164 		cpu_wait = r3081_wait;
165 		break;
166 	case CPU_TX3927:
167 		cpu_wait = r39xx_wait;
168 		break;
169 	case CPU_R4200:
170 /*	case CPU_R4300: */
171 	case CPU_R4600:
172 	case CPU_R4640:
173 	case CPU_R4650:
174 	case CPU_R4700:
175 	case CPU_R5000:
176 	case CPU_R5500:
177 	case CPU_NEVADA:
178 	case CPU_4KC:
179 	case CPU_4KEC:
180 	case CPU_4KSC:
181 	case CPU_5KC:
182 	case CPU_25KF:
183 	case CPU_PR4450:
184 	case CPU_BCM3302:
185 	case CPU_BCM6338:
186 	case CPU_BCM6348:
187 	case CPU_BCM6358:
188 	case CPU_CAVIUM_OCTEON:
189 	case CPU_CAVIUM_OCTEON_PLUS:
190 		cpu_wait = r4k_wait;
191 		break;
192 
193 	case CPU_RM7000:
194 		cpu_wait = rm7k_wait_irqoff;
195 		break;
196 
197 	case CPU_24K:
198 	case CPU_34K:
199 	case CPU_1004K:
200 		cpu_wait = r4k_wait;
201 		if (read_c0_config7() & MIPS_CONF7_WII)
202 			cpu_wait = r4k_wait_irqoff;
203 		break;
204 
205 	case CPU_74K:
206 		cpu_wait = r4k_wait;
207 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
208 			cpu_wait = r4k_wait_irqoff;
209 		break;
210 
211 	case CPU_TX49XX:
212 		cpu_wait = r4k_wait_irqoff;
213 		break;
214 	case CPU_ALCHEMY:
215 		cpu_wait = au1k_wait;
216 		break;
217 	case CPU_20KC:
218 		/*
219 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
220 		 * WAIT on Rev2.0 and Rev3.0 has E16.
221 		 * Rev3.1 WAIT is nop, why bother
222 		 */
223 		if ((c->processor_id & 0xff) <= 0x64)
224 			break;
225 
226 		/*
227 		 * Another rev is incremeting c0_count at a reduced clock
228 		 * rate while in WAIT mode.  So we basically have the choice
229 		 * between using the cp0 timer as clocksource or avoiding
230 		 * the WAIT instruction.  Until more details are known,
231 		 * disable the use of WAIT for 20Kc entirely.
232 		   cpu_wait = r4k_wait;
233 		 */
234 		break;
235 	case CPU_RM9000:
236 		if ((c->processor_id & 0x00ff) >= 0x40)
237 			cpu_wait = r4k_wait;
238 		break;
239 	default:
240 		break;
241 	}
242 }
243 
244 static inline void check_errata(void)
245 {
246 	struct cpuinfo_mips *c = &current_cpu_data;
247 
248 	switch (c->cputype) {
249 	case CPU_34K:
250 		/*
251 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
252 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
253 		 * making use of VPE1 will be responsable for that VPE.
254 		 */
255 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
256 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
257 		break;
258 	default:
259 		break;
260 	}
261 }
262 
263 void __init check_bugs32(void)
264 {
265 	check_errata();
266 }
267 
268 /*
269  * Probe whether cpu has config register by trying to play with
270  * alternate cache bit and see whether it matters.
271  * It's used by cpu_probe to distinguish between R3000A and R3081.
272  */
273 static inline int cpu_has_confreg(void)
274 {
275 #ifdef CONFIG_CPU_R3000
276 	extern unsigned long r3k_cache_size(unsigned long);
277 	unsigned long size1, size2;
278 	unsigned long cfg = read_c0_conf();
279 
280 	size1 = r3k_cache_size(ST0_ISC);
281 	write_c0_conf(cfg ^ R30XX_CONF_AC);
282 	size2 = r3k_cache_size(ST0_ISC);
283 	write_c0_conf(cfg);
284 	return size1 != size2;
285 #else
286 	return 0;
287 #endif
288 }
289 
290 /*
291  * Get the FPU Implementation/Revision.
292  */
293 static inline unsigned long cpu_get_fpu_id(void)
294 {
295 	unsigned long tmp, fpu_id;
296 
297 	tmp = read_c0_status();
298 	__enable_fpu();
299 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
300 	write_c0_status(tmp);
301 	return fpu_id;
302 }
303 
304 /*
305  * Check the CPU has an FPU the official way.
306  */
307 static inline int __cpu_has_fpu(void)
308 {
309 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
310 }
311 
312 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
313 {
314 #ifdef __NEED_VMBITS_PROBE
315 	write_c0_entryhi(0x3fffffffffffe000ULL);
316 	back_to_back_c0_hazard();
317 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
318 #endif
319 }
320 
321 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
322 		| MIPS_CPU_COUNTER)
323 
324 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
325 {
326 	switch (c->processor_id & 0xff00) {
327 	case PRID_IMP_R2000:
328 		c->cputype = CPU_R2000;
329 		__cpu_name[cpu] = "R2000";
330 		c->isa_level = MIPS_CPU_ISA_I;
331 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
332 		             MIPS_CPU_NOFPUEX;
333 		if (__cpu_has_fpu())
334 			c->options |= MIPS_CPU_FPU;
335 		c->tlbsize = 64;
336 		break;
337 	case PRID_IMP_R3000:
338 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
339 			if (cpu_has_confreg()) {
340 				c->cputype = CPU_R3081E;
341 				__cpu_name[cpu] = "R3081";
342 			} else {
343 				c->cputype = CPU_R3000A;
344 				__cpu_name[cpu] = "R3000A";
345 			}
346 			break;
347 		} else {
348 			c->cputype = CPU_R3000;
349 			__cpu_name[cpu] = "R3000";
350 		}
351 		c->isa_level = MIPS_CPU_ISA_I;
352 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
353 		             MIPS_CPU_NOFPUEX;
354 		if (__cpu_has_fpu())
355 			c->options |= MIPS_CPU_FPU;
356 		c->tlbsize = 64;
357 		break;
358 	case PRID_IMP_R4000:
359 		if (read_c0_config() & CONF_SC) {
360 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
361 				c->cputype = CPU_R4400PC;
362 				__cpu_name[cpu] = "R4400PC";
363 			} else {
364 				c->cputype = CPU_R4000PC;
365 				__cpu_name[cpu] = "R4000PC";
366 			}
367 		} else {
368 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
369 				c->cputype = CPU_R4400SC;
370 				__cpu_name[cpu] = "R4400SC";
371 			} else {
372 				c->cputype = CPU_R4000SC;
373 				__cpu_name[cpu] = "R4000SC";
374 			}
375 		}
376 
377 		c->isa_level = MIPS_CPU_ISA_III;
378 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
379 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
380 		             MIPS_CPU_LLSC;
381 		c->tlbsize = 48;
382 		break;
383 	case PRID_IMP_VR41XX:
384 		switch (c->processor_id & 0xf0) {
385 		case PRID_REV_VR4111:
386 			c->cputype = CPU_VR4111;
387 			__cpu_name[cpu] = "NEC VR4111";
388 			break;
389 		case PRID_REV_VR4121:
390 			c->cputype = CPU_VR4121;
391 			__cpu_name[cpu] = "NEC VR4121";
392 			break;
393 		case PRID_REV_VR4122:
394 			if ((c->processor_id & 0xf) < 0x3) {
395 				c->cputype = CPU_VR4122;
396 				__cpu_name[cpu] = "NEC VR4122";
397 			} else {
398 				c->cputype = CPU_VR4181A;
399 				__cpu_name[cpu] = "NEC VR4181A";
400 			}
401 			break;
402 		case PRID_REV_VR4130:
403 			if ((c->processor_id & 0xf) < 0x4) {
404 				c->cputype = CPU_VR4131;
405 				__cpu_name[cpu] = "NEC VR4131";
406 			} else {
407 				c->cputype = CPU_VR4133;
408 				__cpu_name[cpu] = "NEC VR4133";
409 			}
410 			break;
411 		default:
412 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
413 			c->cputype = CPU_VR41XX;
414 			__cpu_name[cpu] = "NEC Vr41xx";
415 			break;
416 		}
417 		c->isa_level = MIPS_CPU_ISA_III;
418 		c->options = R4K_OPTS;
419 		c->tlbsize = 32;
420 		break;
421 	case PRID_IMP_R4300:
422 		c->cputype = CPU_R4300;
423 		__cpu_name[cpu] = "R4300";
424 		c->isa_level = MIPS_CPU_ISA_III;
425 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
426 		             MIPS_CPU_LLSC;
427 		c->tlbsize = 32;
428 		break;
429 	case PRID_IMP_R4600:
430 		c->cputype = CPU_R4600;
431 		__cpu_name[cpu] = "R4600";
432 		c->isa_level = MIPS_CPU_ISA_III;
433 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
434 			     MIPS_CPU_LLSC;
435 		c->tlbsize = 48;
436 		break;
437 	#if 0
438  	case PRID_IMP_R4650:
439 		/*
440 		 * This processor doesn't have an MMU, so it's not
441 		 * "real easy" to run Linux on it. It is left purely
442 		 * for documentation.  Commented out because it shares
443 		 * it's c0_prid id number with the TX3900.
444 		 */
445 		c->cputype = CPU_R4650;
446 		__cpu_name[cpu] = "R4650";
447 	 	c->isa_level = MIPS_CPU_ISA_III;
448 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
449 	        c->tlbsize = 48;
450 		break;
451 	#endif
452 	case PRID_IMP_TX39:
453 		c->isa_level = MIPS_CPU_ISA_I;
454 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
455 
456 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
457 			c->cputype = CPU_TX3927;
458 			__cpu_name[cpu] = "TX3927";
459 			c->tlbsize = 64;
460 		} else {
461 			switch (c->processor_id & 0xff) {
462 			case PRID_REV_TX3912:
463 				c->cputype = CPU_TX3912;
464 				__cpu_name[cpu] = "TX3912";
465 				c->tlbsize = 32;
466 				break;
467 			case PRID_REV_TX3922:
468 				c->cputype = CPU_TX3922;
469 				__cpu_name[cpu] = "TX3922";
470 				c->tlbsize = 64;
471 				break;
472 			}
473 		}
474 		break;
475 	case PRID_IMP_R4700:
476 		c->cputype = CPU_R4700;
477 		__cpu_name[cpu] = "R4700";
478 		c->isa_level = MIPS_CPU_ISA_III;
479 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
480 		             MIPS_CPU_LLSC;
481 		c->tlbsize = 48;
482 		break;
483 	case PRID_IMP_TX49:
484 		c->cputype = CPU_TX49XX;
485 		__cpu_name[cpu] = "R49XX";
486 		c->isa_level = MIPS_CPU_ISA_III;
487 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
488 		if (!(c->processor_id & 0x08))
489 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
490 		c->tlbsize = 48;
491 		break;
492 	case PRID_IMP_R5000:
493 		c->cputype = CPU_R5000;
494 		__cpu_name[cpu] = "R5000";
495 		c->isa_level = MIPS_CPU_ISA_IV;
496 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
497 		             MIPS_CPU_LLSC;
498 		c->tlbsize = 48;
499 		break;
500 	case PRID_IMP_R5432:
501 		c->cputype = CPU_R5432;
502 		__cpu_name[cpu] = "R5432";
503 		c->isa_level = MIPS_CPU_ISA_IV;
504 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
505 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
506 		c->tlbsize = 48;
507 		break;
508 	case PRID_IMP_R5500:
509 		c->cputype = CPU_R5500;
510 		__cpu_name[cpu] = "R5500";
511 		c->isa_level = MIPS_CPU_ISA_IV;
512 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
513 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
514 		c->tlbsize = 48;
515 		break;
516 	case PRID_IMP_NEVADA:
517 		c->cputype = CPU_NEVADA;
518 		__cpu_name[cpu] = "Nevada";
519 		c->isa_level = MIPS_CPU_ISA_IV;
520 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
521 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
522 		c->tlbsize = 48;
523 		break;
524 	case PRID_IMP_R6000:
525 		c->cputype = CPU_R6000;
526 		__cpu_name[cpu] = "R6000";
527 		c->isa_level = MIPS_CPU_ISA_II;
528 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
529 		             MIPS_CPU_LLSC;
530 		c->tlbsize = 32;
531 		break;
532 	case PRID_IMP_R6000A:
533 		c->cputype = CPU_R6000A;
534 		__cpu_name[cpu] = "R6000A";
535 		c->isa_level = MIPS_CPU_ISA_II;
536 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
537 		             MIPS_CPU_LLSC;
538 		c->tlbsize = 32;
539 		break;
540 	case PRID_IMP_RM7000:
541 		c->cputype = CPU_RM7000;
542 		__cpu_name[cpu] = "RM7000";
543 		c->isa_level = MIPS_CPU_ISA_IV;
544 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
545 		             MIPS_CPU_LLSC;
546 		/*
547 		 * Undocumented RM7000:  Bit 29 in the info register of
548 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
549 		 * entries.
550 		 *
551 		 * 29      1 =>    64 entry JTLB
552 		 *         0 =>    48 entry JTLB
553 		 */
554 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
555 		break;
556 	case PRID_IMP_RM9000:
557 		c->cputype = CPU_RM9000;
558 		__cpu_name[cpu] = "RM9000";
559 		c->isa_level = MIPS_CPU_ISA_IV;
560 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
561 		             MIPS_CPU_LLSC;
562 		/*
563 		 * Bit 29 in the info register of the RM9000
564 		 * indicates if the TLB has 48 or 64 entries.
565 		 *
566 		 * 29      1 =>    64 entry JTLB
567 		 *         0 =>    48 entry JTLB
568 		 */
569 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
570 		break;
571 	case PRID_IMP_R8000:
572 		c->cputype = CPU_R8000;
573 		__cpu_name[cpu] = "RM8000";
574 		c->isa_level = MIPS_CPU_ISA_IV;
575 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
576 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
577 		             MIPS_CPU_LLSC;
578 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
579 		break;
580 	case PRID_IMP_R10000:
581 		c->cputype = CPU_R10000;
582 		__cpu_name[cpu] = "R10000";
583 		c->isa_level = MIPS_CPU_ISA_IV;
584 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
585 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
586 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
587 		             MIPS_CPU_LLSC;
588 		c->tlbsize = 64;
589 		break;
590 	case PRID_IMP_R12000:
591 		c->cputype = CPU_R12000;
592 		__cpu_name[cpu] = "R12000";
593 		c->isa_level = MIPS_CPU_ISA_IV;
594 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
595 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
596 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
597 		             MIPS_CPU_LLSC;
598 		c->tlbsize = 64;
599 		break;
600 	case PRID_IMP_R14000:
601 		c->cputype = CPU_R14000;
602 		__cpu_name[cpu] = "R14000";
603 		c->isa_level = MIPS_CPU_ISA_IV;
604 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
605 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
606 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
607 		             MIPS_CPU_LLSC;
608 		c->tlbsize = 64;
609 		break;
610 	case PRID_IMP_LOONGSON2:
611 		c->cputype = CPU_LOONGSON2;
612 		__cpu_name[cpu] = "ICT Loongson-2";
613 		c->isa_level = MIPS_CPU_ISA_III;
614 		c->options = R4K_OPTS |
615 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
616 			     MIPS_CPU_32FPR;
617 		c->tlbsize = 64;
618 		break;
619 	}
620 }
621 
622 static char unknown_isa[] __cpuinitdata = KERN_ERR \
623 	"Unsupported ISA type, c0.config0: %d.";
624 
625 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
626 {
627 	unsigned int config0;
628 	int isa;
629 
630 	config0 = read_c0_config();
631 
632 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
633 		c->options |= MIPS_CPU_TLB;
634 	isa = (config0 & MIPS_CONF_AT) >> 13;
635 	switch (isa) {
636 	case 0:
637 		switch ((config0 & MIPS_CONF_AR) >> 10) {
638 		case 0:
639 			c->isa_level = MIPS_CPU_ISA_M32R1;
640 			break;
641 		case 1:
642 			c->isa_level = MIPS_CPU_ISA_M32R2;
643 			break;
644 		default:
645 			goto unknown;
646 		}
647 		break;
648 	case 2:
649 		switch ((config0 & MIPS_CONF_AR) >> 10) {
650 		case 0:
651 			c->isa_level = MIPS_CPU_ISA_M64R1;
652 			break;
653 		case 1:
654 			c->isa_level = MIPS_CPU_ISA_M64R2;
655 			break;
656 		default:
657 			goto unknown;
658 		}
659 		break;
660 	default:
661 		goto unknown;
662 	}
663 
664 	return config0 & MIPS_CONF_M;
665 
666 unknown:
667 	panic(unknown_isa, config0);
668 }
669 
670 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
671 {
672 	unsigned int config1;
673 
674 	config1 = read_c0_config1();
675 
676 	if (config1 & MIPS_CONF1_MD)
677 		c->ases |= MIPS_ASE_MDMX;
678 	if (config1 & MIPS_CONF1_WR)
679 		c->options |= MIPS_CPU_WATCH;
680 	if (config1 & MIPS_CONF1_CA)
681 		c->ases |= MIPS_ASE_MIPS16;
682 	if (config1 & MIPS_CONF1_EP)
683 		c->options |= MIPS_CPU_EJTAG;
684 	if (config1 & MIPS_CONF1_FP) {
685 		c->options |= MIPS_CPU_FPU;
686 		c->options |= MIPS_CPU_32FPR;
687 	}
688 	if (cpu_has_tlb)
689 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
690 
691 	return config1 & MIPS_CONF_M;
692 }
693 
694 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
695 {
696 	unsigned int config2;
697 
698 	config2 = read_c0_config2();
699 
700 	if (config2 & MIPS_CONF2_SL)
701 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
702 
703 	return config2 & MIPS_CONF_M;
704 }
705 
706 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
707 {
708 	unsigned int config3;
709 
710 	config3 = read_c0_config3();
711 
712 	if (config3 & MIPS_CONF3_SM)
713 		c->ases |= MIPS_ASE_SMARTMIPS;
714 	if (config3 & MIPS_CONF3_DSP)
715 		c->ases |= MIPS_ASE_DSP;
716 	if (config3 & MIPS_CONF3_VINT)
717 		c->options |= MIPS_CPU_VINT;
718 	if (config3 & MIPS_CONF3_VEIC)
719 		c->options |= MIPS_CPU_VEIC;
720 	if (config3 & MIPS_CONF3_MT)
721 	        c->ases |= MIPS_ASE_MIPSMT;
722 	if (config3 & MIPS_CONF3_ULRI)
723 		c->options |= MIPS_CPU_ULRI;
724 
725 	return config3 & MIPS_CONF_M;
726 }
727 
728 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
729 {
730 	unsigned int config4;
731 
732 	config4 = read_c0_config4();
733 
734 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
735 	    && cpu_has_tlb)
736 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
737 
738 	return config4 & MIPS_CONF_M;
739 }
740 
741 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
742 {
743 	int ok;
744 
745 	/* MIPS32 or MIPS64 compliant CPU.  */
746 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
747 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
748 
749 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
750 
751 	ok = decode_config0(c);			/* Read Config registers.  */
752 	BUG_ON(!ok);				/* Arch spec violation!  */
753 	if (ok)
754 		ok = decode_config1(c);
755 	if (ok)
756 		ok = decode_config2(c);
757 	if (ok)
758 		ok = decode_config3(c);
759 	if (ok)
760 		ok = decode_config4(c);
761 
762 	mips_probe_watch_registers(c);
763 }
764 
765 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
766 {
767 	decode_configs(c);
768 	switch (c->processor_id & 0xff00) {
769 	case PRID_IMP_4KC:
770 		c->cputype = CPU_4KC;
771 		__cpu_name[cpu] = "MIPS 4Kc";
772 		break;
773 	case PRID_IMP_4KEC:
774 	case PRID_IMP_4KECR2:
775 		c->cputype = CPU_4KEC;
776 		__cpu_name[cpu] = "MIPS 4KEc";
777 		break;
778 	case PRID_IMP_4KSC:
779 	case PRID_IMP_4KSD:
780 		c->cputype = CPU_4KSC;
781 		__cpu_name[cpu] = "MIPS 4KSc";
782 		break;
783 	case PRID_IMP_5KC:
784 		c->cputype = CPU_5KC;
785 		__cpu_name[cpu] = "MIPS 5Kc";
786 		break;
787 	case PRID_IMP_20KC:
788 		c->cputype = CPU_20KC;
789 		__cpu_name[cpu] = "MIPS 20Kc";
790 		break;
791 	case PRID_IMP_24K:
792 	case PRID_IMP_24KE:
793 		c->cputype = CPU_24K;
794 		__cpu_name[cpu] = "MIPS 24Kc";
795 		break;
796 	case PRID_IMP_25KF:
797 		c->cputype = CPU_25KF;
798 		__cpu_name[cpu] = "MIPS 25Kc";
799 		break;
800 	case PRID_IMP_34K:
801 		c->cputype = CPU_34K;
802 		__cpu_name[cpu] = "MIPS 34Kc";
803 		break;
804 	case PRID_IMP_74K:
805 		c->cputype = CPU_74K;
806 		__cpu_name[cpu] = "MIPS 74Kc";
807 		break;
808 	case PRID_IMP_1004K:
809 		c->cputype = CPU_1004K;
810 		__cpu_name[cpu] = "MIPS 1004Kc";
811 		break;
812 	}
813 
814 	spram_config();
815 }
816 
817 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
818 {
819 	decode_configs(c);
820 	switch (c->processor_id & 0xff00) {
821 	case PRID_IMP_AU1_REV1:
822 	case PRID_IMP_AU1_REV2:
823 		c->cputype = CPU_ALCHEMY;
824 		switch ((c->processor_id >> 24) & 0xff) {
825 		case 0:
826 			__cpu_name[cpu] = "Au1000";
827 			break;
828 		case 1:
829 			__cpu_name[cpu] = "Au1500";
830 			break;
831 		case 2:
832 			__cpu_name[cpu] = "Au1100";
833 			break;
834 		case 3:
835 			__cpu_name[cpu] = "Au1550";
836 			break;
837 		case 4:
838 			__cpu_name[cpu] = "Au1200";
839 			if ((c->processor_id & 0xff) == 2)
840 				__cpu_name[cpu] = "Au1250";
841 			break;
842 		case 5:
843 			__cpu_name[cpu] = "Au1210";
844 			break;
845 		default:
846 			__cpu_name[cpu] = "Au1xxx";
847 			break;
848 		}
849 		break;
850 	}
851 }
852 
853 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
854 {
855 	decode_configs(c);
856 
857 	switch (c->processor_id & 0xff00) {
858 	case PRID_IMP_SB1:
859 		c->cputype = CPU_SB1;
860 		__cpu_name[cpu] = "SiByte SB1";
861 		/* FPU in pass1 is known to have issues. */
862 		if ((c->processor_id & 0xff) < 0x02)
863 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
864 		break;
865 	case PRID_IMP_SB1A:
866 		c->cputype = CPU_SB1A;
867 		__cpu_name[cpu] = "SiByte SB1A";
868 		break;
869 	}
870 }
871 
872 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
873 {
874 	decode_configs(c);
875 	switch (c->processor_id & 0xff00) {
876 	case PRID_IMP_SR71000:
877 		c->cputype = CPU_SR71000;
878 		__cpu_name[cpu] = "Sandcraft SR71000";
879 		c->scache.ways = 8;
880 		c->tlbsize = 64;
881 		break;
882 	}
883 }
884 
885 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
886 {
887 	decode_configs(c);
888 	switch (c->processor_id & 0xff00) {
889 	case PRID_IMP_PR4450:
890 		c->cputype = CPU_PR4450;
891 		__cpu_name[cpu] = "Philips PR4450";
892 		c->isa_level = MIPS_CPU_ISA_M32R1;
893 		break;
894 	}
895 }
896 
897 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
898 {
899 	decode_configs(c);
900 	switch (c->processor_id & 0xff00) {
901 	case PRID_IMP_BCM3302:
902 	 /* same as PRID_IMP_BCM6338 */
903 		c->cputype = CPU_BCM3302;
904 		__cpu_name[cpu] = "Broadcom BCM3302";
905 		break;
906 	case PRID_IMP_BCM4710:
907 		c->cputype = CPU_BCM4710;
908 		__cpu_name[cpu] = "Broadcom BCM4710";
909 		break;
910 	case PRID_IMP_BCM6345:
911 		c->cputype = CPU_BCM6345;
912 		__cpu_name[cpu] = "Broadcom BCM6345";
913 		break;
914 	case PRID_IMP_BCM6348:
915 		c->cputype = CPU_BCM6348;
916 		__cpu_name[cpu] = "Broadcom BCM6348";
917 		break;
918 	case PRID_IMP_BCM4350:
919 		switch (c->processor_id & 0xf0) {
920 		case PRID_REV_BCM6358:
921 			c->cputype = CPU_BCM6358;
922 			__cpu_name[cpu] = "Broadcom BCM6358";
923 			break;
924 		default:
925 			c->cputype = CPU_UNKNOWN;
926 			break;
927 		}
928 		break;
929 	}
930 }
931 
932 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
933 {
934 	decode_configs(c);
935 	switch (c->processor_id & 0xff00) {
936 	case PRID_IMP_CAVIUM_CN38XX:
937 	case PRID_IMP_CAVIUM_CN31XX:
938 	case PRID_IMP_CAVIUM_CN30XX:
939 		c->cputype = CPU_CAVIUM_OCTEON;
940 		__cpu_name[cpu] = "Cavium Octeon";
941 		goto platform;
942 	case PRID_IMP_CAVIUM_CN58XX:
943 	case PRID_IMP_CAVIUM_CN56XX:
944 	case PRID_IMP_CAVIUM_CN50XX:
945 	case PRID_IMP_CAVIUM_CN52XX:
946 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
947 		__cpu_name[cpu] = "Cavium Octeon+";
948 platform:
949 		if (cpu == 0)
950 			__elf_platform = "octeon";
951 		break;
952 	default:
953 		printk(KERN_INFO "Unknown Octeon chip!\n");
954 		c->cputype = CPU_UNKNOWN;
955 		break;
956 	}
957 }
958 
959 const char *__cpu_name[NR_CPUS];
960 const char *__elf_platform;
961 
962 __cpuinit void cpu_probe(void)
963 {
964 	struct cpuinfo_mips *c = &current_cpu_data;
965 	unsigned int cpu = smp_processor_id();
966 
967 	c->processor_id	= PRID_IMP_UNKNOWN;
968 	c->fpu_id	= FPIR_IMP_NONE;
969 	c->cputype	= CPU_UNKNOWN;
970 
971 	c->processor_id = read_c0_prid();
972 	switch (c->processor_id & 0xff0000) {
973 	case PRID_COMP_LEGACY:
974 		cpu_probe_legacy(c, cpu);
975 		break;
976 	case PRID_COMP_MIPS:
977 		cpu_probe_mips(c, cpu);
978 		break;
979 	case PRID_COMP_ALCHEMY:
980 		cpu_probe_alchemy(c, cpu);
981 		break;
982 	case PRID_COMP_SIBYTE:
983 		cpu_probe_sibyte(c, cpu);
984 		break;
985 	case PRID_COMP_BROADCOM:
986 		cpu_probe_broadcom(c, cpu);
987 		break;
988 	case PRID_COMP_SANDCRAFT:
989 		cpu_probe_sandcraft(c, cpu);
990 		break;
991 	case PRID_COMP_NXP:
992 		cpu_probe_nxp(c, cpu);
993 		break;
994 	case PRID_COMP_CAVIUM:
995 		cpu_probe_cavium(c, cpu);
996 		break;
997 	}
998 
999 	BUG_ON(!__cpu_name[cpu]);
1000 	BUG_ON(c->cputype == CPU_UNKNOWN);
1001 
1002 	/*
1003 	 * Platform code can force the cpu type to optimize code
1004 	 * generation. In that case be sure the cpu type is correctly
1005 	 * manually setup otherwise it could trigger some nasty bugs.
1006 	 */
1007 	BUG_ON(current_cpu_type() != c->cputype);
1008 
1009 	if (mips_fpu_disabled)
1010 		c->options &= ~MIPS_CPU_FPU;
1011 
1012 	if (mips_dsp_disabled)
1013 		c->ases &= ~MIPS_ASE_DSP;
1014 
1015 	if (c->options & MIPS_CPU_FPU) {
1016 		c->fpu_id = cpu_get_fpu_id();
1017 
1018 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1019 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1020 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1021 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1022 			if (c->fpu_id & MIPS_FPIR_3D)
1023 				c->ases |= MIPS_ASE_MIPS3D;
1024 		}
1025 	}
1026 
1027 	if (cpu_has_mips_r2)
1028 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1029 	else
1030 		c->srsets = 1;
1031 
1032 	cpu_probe_vmbits(c);
1033 }
1034 
1035 __cpuinit void cpu_report(void)
1036 {
1037 	struct cpuinfo_mips *c = &current_cpu_data;
1038 
1039 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1040 	       c->processor_id, cpu_name_string());
1041 	if (c->options & MIPS_CPU_FPU)
1042 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1043 }
1044