xref: /linux/arch/mips/kernel/cpu-probe.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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 	case CPU_JZRISC:
191 		cpu_wait = r4k_wait;
192 		break;
193 
194 	case CPU_RM7000:
195 		cpu_wait = rm7k_wait_irqoff;
196 		break;
197 
198 	case CPU_24K:
199 	case CPU_34K:
200 	case CPU_1004K:
201 		cpu_wait = r4k_wait;
202 		if (read_c0_config7() & MIPS_CONF7_WII)
203 			cpu_wait = r4k_wait_irqoff;
204 		break;
205 
206 	case CPU_74K:
207 		cpu_wait = r4k_wait;
208 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
209 			cpu_wait = r4k_wait_irqoff;
210 		break;
211 
212 	case CPU_TX49XX:
213 		cpu_wait = r4k_wait_irqoff;
214 		break;
215 	case CPU_ALCHEMY:
216 		cpu_wait = au1k_wait;
217 		break;
218 	case CPU_20KC:
219 		/*
220 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
221 		 * WAIT on Rev2.0 and Rev3.0 has E16.
222 		 * Rev3.1 WAIT is nop, why bother
223 		 */
224 		if ((c->processor_id & 0xff) <= 0x64)
225 			break;
226 
227 		/*
228 		 * Another rev is incremeting c0_count at a reduced clock
229 		 * rate while in WAIT mode.  So we basically have the choice
230 		 * between using the cp0 timer as clocksource or avoiding
231 		 * the WAIT instruction.  Until more details are known,
232 		 * disable the use of WAIT for 20Kc entirely.
233 		   cpu_wait = r4k_wait;
234 		 */
235 		break;
236 	case CPU_RM9000:
237 		if ((c->processor_id & 0x00ff) >= 0x40)
238 			cpu_wait = r4k_wait;
239 		break;
240 	default:
241 		break;
242 	}
243 }
244 
245 static inline void check_errata(void)
246 {
247 	struct cpuinfo_mips *c = &current_cpu_data;
248 
249 	switch (c->cputype) {
250 	case CPU_34K:
251 		/*
252 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
253 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
254 		 * making use of VPE1 will be responsable for that VPE.
255 		 */
256 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
257 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
258 		break;
259 	default:
260 		break;
261 	}
262 }
263 
264 void __init check_bugs32(void)
265 {
266 	check_errata();
267 }
268 
269 /*
270  * Probe whether cpu has config register by trying to play with
271  * alternate cache bit and see whether it matters.
272  * It's used by cpu_probe to distinguish between R3000A and R3081.
273  */
274 static inline int cpu_has_confreg(void)
275 {
276 #ifdef CONFIG_CPU_R3000
277 	extern unsigned long r3k_cache_size(unsigned long);
278 	unsigned long size1, size2;
279 	unsigned long cfg = read_c0_conf();
280 
281 	size1 = r3k_cache_size(ST0_ISC);
282 	write_c0_conf(cfg ^ R30XX_CONF_AC);
283 	size2 = r3k_cache_size(ST0_ISC);
284 	write_c0_conf(cfg);
285 	return size1 != size2;
286 #else
287 	return 0;
288 #endif
289 }
290 
291 /*
292  * Get the FPU Implementation/Revision.
293  */
294 static inline unsigned long cpu_get_fpu_id(void)
295 {
296 	unsigned long tmp, fpu_id;
297 
298 	tmp = read_c0_status();
299 	__enable_fpu();
300 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
301 	write_c0_status(tmp);
302 	return fpu_id;
303 }
304 
305 /*
306  * Check the CPU has an FPU the official way.
307  */
308 static inline int __cpu_has_fpu(void)
309 {
310 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
311 }
312 
313 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
314 {
315 #ifdef __NEED_VMBITS_PROBE
316 	write_c0_entryhi(0x3fffffffffffe000ULL);
317 	back_to_back_c0_hazard();
318 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
319 #endif
320 }
321 
322 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
323 		| MIPS_CPU_COUNTER)
324 
325 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
326 {
327 	switch (c->processor_id & 0xff00) {
328 	case PRID_IMP_R2000:
329 		c->cputype = CPU_R2000;
330 		__cpu_name[cpu] = "R2000";
331 		c->isa_level = MIPS_CPU_ISA_I;
332 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
333 		             MIPS_CPU_NOFPUEX;
334 		if (__cpu_has_fpu())
335 			c->options |= MIPS_CPU_FPU;
336 		c->tlbsize = 64;
337 		break;
338 	case PRID_IMP_R3000:
339 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
340 			if (cpu_has_confreg()) {
341 				c->cputype = CPU_R3081E;
342 				__cpu_name[cpu] = "R3081";
343 			} else {
344 				c->cputype = CPU_R3000A;
345 				__cpu_name[cpu] = "R3000A";
346 			}
347 			break;
348 		} else {
349 			c->cputype = CPU_R3000;
350 			__cpu_name[cpu] = "R3000";
351 		}
352 		c->isa_level = MIPS_CPU_ISA_I;
353 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
354 		             MIPS_CPU_NOFPUEX;
355 		if (__cpu_has_fpu())
356 			c->options |= MIPS_CPU_FPU;
357 		c->tlbsize = 64;
358 		break;
359 	case PRID_IMP_R4000:
360 		if (read_c0_config() & CONF_SC) {
361 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
362 				c->cputype = CPU_R4400PC;
363 				__cpu_name[cpu] = "R4400PC";
364 			} else {
365 				c->cputype = CPU_R4000PC;
366 				__cpu_name[cpu] = "R4000PC";
367 			}
368 		} else {
369 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
370 				c->cputype = CPU_R4400SC;
371 				__cpu_name[cpu] = "R4400SC";
372 			} else {
373 				c->cputype = CPU_R4000SC;
374 				__cpu_name[cpu] = "R4000SC";
375 			}
376 		}
377 
378 		c->isa_level = MIPS_CPU_ISA_III;
379 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
380 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
381 		             MIPS_CPU_LLSC;
382 		c->tlbsize = 48;
383 		break;
384 	case PRID_IMP_VR41XX:
385 		switch (c->processor_id & 0xf0) {
386 		case PRID_REV_VR4111:
387 			c->cputype = CPU_VR4111;
388 			__cpu_name[cpu] = "NEC VR4111";
389 			break;
390 		case PRID_REV_VR4121:
391 			c->cputype = CPU_VR4121;
392 			__cpu_name[cpu] = "NEC VR4121";
393 			break;
394 		case PRID_REV_VR4122:
395 			if ((c->processor_id & 0xf) < 0x3) {
396 				c->cputype = CPU_VR4122;
397 				__cpu_name[cpu] = "NEC VR4122";
398 			} else {
399 				c->cputype = CPU_VR4181A;
400 				__cpu_name[cpu] = "NEC VR4181A";
401 			}
402 			break;
403 		case PRID_REV_VR4130:
404 			if ((c->processor_id & 0xf) < 0x4) {
405 				c->cputype = CPU_VR4131;
406 				__cpu_name[cpu] = "NEC VR4131";
407 			} else {
408 				c->cputype = CPU_VR4133;
409 				__cpu_name[cpu] = "NEC VR4133";
410 			}
411 			break;
412 		default:
413 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
414 			c->cputype = CPU_VR41XX;
415 			__cpu_name[cpu] = "NEC Vr41xx";
416 			break;
417 		}
418 		c->isa_level = MIPS_CPU_ISA_III;
419 		c->options = R4K_OPTS;
420 		c->tlbsize = 32;
421 		break;
422 	case PRID_IMP_R4300:
423 		c->cputype = CPU_R4300;
424 		__cpu_name[cpu] = "R4300";
425 		c->isa_level = MIPS_CPU_ISA_III;
426 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
427 		             MIPS_CPU_LLSC;
428 		c->tlbsize = 32;
429 		break;
430 	case PRID_IMP_R4600:
431 		c->cputype = CPU_R4600;
432 		__cpu_name[cpu] = "R4600";
433 		c->isa_level = MIPS_CPU_ISA_III;
434 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
435 			     MIPS_CPU_LLSC;
436 		c->tlbsize = 48;
437 		break;
438 	#if 0
439  	case PRID_IMP_R4650:
440 		/*
441 		 * This processor doesn't have an MMU, so it's not
442 		 * "real easy" to run Linux on it. It is left purely
443 		 * for documentation.  Commented out because it shares
444 		 * it's c0_prid id number with the TX3900.
445 		 */
446 		c->cputype = CPU_R4650;
447 		__cpu_name[cpu] = "R4650";
448 	 	c->isa_level = MIPS_CPU_ISA_III;
449 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
450 	        c->tlbsize = 48;
451 		break;
452 	#endif
453 	case PRID_IMP_TX39:
454 		c->isa_level = MIPS_CPU_ISA_I;
455 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
456 
457 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
458 			c->cputype = CPU_TX3927;
459 			__cpu_name[cpu] = "TX3927";
460 			c->tlbsize = 64;
461 		} else {
462 			switch (c->processor_id & 0xff) {
463 			case PRID_REV_TX3912:
464 				c->cputype = CPU_TX3912;
465 				__cpu_name[cpu] = "TX3912";
466 				c->tlbsize = 32;
467 				break;
468 			case PRID_REV_TX3922:
469 				c->cputype = CPU_TX3922;
470 				__cpu_name[cpu] = "TX3922";
471 				c->tlbsize = 64;
472 				break;
473 			}
474 		}
475 		break;
476 	case PRID_IMP_R4700:
477 		c->cputype = CPU_R4700;
478 		__cpu_name[cpu] = "R4700";
479 		c->isa_level = MIPS_CPU_ISA_III;
480 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
481 		             MIPS_CPU_LLSC;
482 		c->tlbsize = 48;
483 		break;
484 	case PRID_IMP_TX49:
485 		c->cputype = CPU_TX49XX;
486 		__cpu_name[cpu] = "R49XX";
487 		c->isa_level = MIPS_CPU_ISA_III;
488 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
489 		if (!(c->processor_id & 0x08))
490 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
491 		c->tlbsize = 48;
492 		break;
493 	case PRID_IMP_R5000:
494 		c->cputype = CPU_R5000;
495 		__cpu_name[cpu] = "R5000";
496 		c->isa_level = MIPS_CPU_ISA_IV;
497 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
498 		             MIPS_CPU_LLSC;
499 		c->tlbsize = 48;
500 		break;
501 	case PRID_IMP_R5432:
502 		c->cputype = CPU_R5432;
503 		__cpu_name[cpu] = "R5432";
504 		c->isa_level = MIPS_CPU_ISA_IV;
505 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
506 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
507 		c->tlbsize = 48;
508 		break;
509 	case PRID_IMP_R5500:
510 		c->cputype = CPU_R5500;
511 		__cpu_name[cpu] = "R5500";
512 		c->isa_level = MIPS_CPU_ISA_IV;
513 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
514 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
515 		c->tlbsize = 48;
516 		break;
517 	case PRID_IMP_NEVADA:
518 		c->cputype = CPU_NEVADA;
519 		__cpu_name[cpu] = "Nevada";
520 		c->isa_level = MIPS_CPU_ISA_IV;
521 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
522 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
523 		c->tlbsize = 48;
524 		break;
525 	case PRID_IMP_R6000:
526 		c->cputype = CPU_R6000;
527 		__cpu_name[cpu] = "R6000";
528 		c->isa_level = MIPS_CPU_ISA_II;
529 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
530 		             MIPS_CPU_LLSC;
531 		c->tlbsize = 32;
532 		break;
533 	case PRID_IMP_R6000A:
534 		c->cputype = CPU_R6000A;
535 		__cpu_name[cpu] = "R6000A";
536 		c->isa_level = MIPS_CPU_ISA_II;
537 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
538 		             MIPS_CPU_LLSC;
539 		c->tlbsize = 32;
540 		break;
541 	case PRID_IMP_RM7000:
542 		c->cputype = CPU_RM7000;
543 		__cpu_name[cpu] = "RM7000";
544 		c->isa_level = MIPS_CPU_ISA_IV;
545 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
546 		             MIPS_CPU_LLSC;
547 		/*
548 		 * Undocumented RM7000:  Bit 29 in the info register of
549 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
550 		 * entries.
551 		 *
552 		 * 29      1 =>    64 entry JTLB
553 		 *         0 =>    48 entry JTLB
554 		 */
555 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
556 		break;
557 	case PRID_IMP_RM9000:
558 		c->cputype = CPU_RM9000;
559 		__cpu_name[cpu] = "RM9000";
560 		c->isa_level = MIPS_CPU_ISA_IV;
561 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
562 		             MIPS_CPU_LLSC;
563 		/*
564 		 * Bit 29 in the info register of the RM9000
565 		 * indicates if the TLB has 48 or 64 entries.
566 		 *
567 		 * 29      1 =>    64 entry JTLB
568 		 *         0 =>    48 entry JTLB
569 		 */
570 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
571 		break;
572 	case PRID_IMP_R8000:
573 		c->cputype = CPU_R8000;
574 		__cpu_name[cpu] = "RM8000";
575 		c->isa_level = MIPS_CPU_ISA_IV;
576 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
577 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
578 		             MIPS_CPU_LLSC;
579 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
580 		break;
581 	case PRID_IMP_R10000:
582 		c->cputype = CPU_R10000;
583 		__cpu_name[cpu] = "R10000";
584 		c->isa_level = MIPS_CPU_ISA_IV;
585 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
586 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
587 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
588 		             MIPS_CPU_LLSC;
589 		c->tlbsize = 64;
590 		break;
591 	case PRID_IMP_R12000:
592 		c->cputype = CPU_R12000;
593 		__cpu_name[cpu] = "R12000";
594 		c->isa_level = MIPS_CPU_ISA_IV;
595 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
596 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
597 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
598 		             MIPS_CPU_LLSC;
599 		c->tlbsize = 64;
600 		break;
601 	case PRID_IMP_R14000:
602 		c->cputype = CPU_R14000;
603 		__cpu_name[cpu] = "R14000";
604 		c->isa_level = MIPS_CPU_ISA_IV;
605 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
606 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
607 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
608 		             MIPS_CPU_LLSC;
609 		c->tlbsize = 64;
610 		break;
611 	case PRID_IMP_LOONGSON2:
612 		c->cputype = CPU_LOONGSON2;
613 		__cpu_name[cpu] = "ICT Loongson-2";
614 		c->isa_level = MIPS_CPU_ISA_III;
615 		c->options = R4K_OPTS |
616 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
617 			     MIPS_CPU_32FPR;
618 		c->tlbsize = 64;
619 		break;
620 	}
621 }
622 
623 static char unknown_isa[] __cpuinitdata = KERN_ERR \
624 	"Unsupported ISA type, c0.config0: %d.";
625 
626 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
627 {
628 	unsigned int config0;
629 	int isa;
630 
631 	config0 = read_c0_config();
632 
633 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
634 		c->options |= MIPS_CPU_TLB;
635 	isa = (config0 & MIPS_CONF_AT) >> 13;
636 	switch (isa) {
637 	case 0:
638 		switch ((config0 & MIPS_CONF_AR) >> 10) {
639 		case 0:
640 			c->isa_level = MIPS_CPU_ISA_M32R1;
641 			break;
642 		case 1:
643 			c->isa_level = MIPS_CPU_ISA_M32R2;
644 			break;
645 		default:
646 			goto unknown;
647 		}
648 		break;
649 	case 2:
650 		switch ((config0 & MIPS_CONF_AR) >> 10) {
651 		case 0:
652 			c->isa_level = MIPS_CPU_ISA_M64R1;
653 			break;
654 		case 1:
655 			c->isa_level = MIPS_CPU_ISA_M64R2;
656 			break;
657 		default:
658 			goto unknown;
659 		}
660 		break;
661 	default:
662 		goto unknown;
663 	}
664 
665 	return config0 & MIPS_CONF_M;
666 
667 unknown:
668 	panic(unknown_isa, config0);
669 }
670 
671 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
672 {
673 	unsigned int config1;
674 
675 	config1 = read_c0_config1();
676 
677 	if (config1 & MIPS_CONF1_MD)
678 		c->ases |= MIPS_ASE_MDMX;
679 	if (config1 & MIPS_CONF1_WR)
680 		c->options |= MIPS_CPU_WATCH;
681 	if (config1 & MIPS_CONF1_CA)
682 		c->ases |= MIPS_ASE_MIPS16;
683 	if (config1 & MIPS_CONF1_EP)
684 		c->options |= MIPS_CPU_EJTAG;
685 	if (config1 & MIPS_CONF1_FP) {
686 		c->options |= MIPS_CPU_FPU;
687 		c->options |= MIPS_CPU_32FPR;
688 	}
689 	if (cpu_has_tlb)
690 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
691 
692 	return config1 & MIPS_CONF_M;
693 }
694 
695 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
696 {
697 	unsigned int config2;
698 
699 	config2 = read_c0_config2();
700 
701 	if (config2 & MIPS_CONF2_SL)
702 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
703 
704 	return config2 & MIPS_CONF_M;
705 }
706 
707 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
708 {
709 	unsigned int config3;
710 
711 	config3 = read_c0_config3();
712 
713 	if (config3 & MIPS_CONF3_SM)
714 		c->ases |= MIPS_ASE_SMARTMIPS;
715 	if (config3 & MIPS_CONF3_DSP)
716 		c->ases |= MIPS_ASE_DSP;
717 	if (config3 & MIPS_CONF3_VINT)
718 		c->options |= MIPS_CPU_VINT;
719 	if (config3 & MIPS_CONF3_VEIC)
720 		c->options |= MIPS_CPU_VEIC;
721 	if (config3 & MIPS_CONF3_MT)
722 	        c->ases |= MIPS_ASE_MIPSMT;
723 	if (config3 & MIPS_CONF3_ULRI)
724 		c->options |= MIPS_CPU_ULRI;
725 
726 	return config3 & MIPS_CONF_M;
727 }
728 
729 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
730 {
731 	unsigned int config4;
732 
733 	config4 = read_c0_config4();
734 
735 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
736 	    && cpu_has_tlb)
737 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
738 
739 	return config4 & MIPS_CONF_M;
740 }
741 
742 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
743 {
744 	int ok;
745 
746 	/* MIPS32 or MIPS64 compliant CPU.  */
747 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
748 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
749 
750 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
751 
752 	ok = decode_config0(c);			/* Read Config registers.  */
753 	BUG_ON(!ok);				/* Arch spec violation!  */
754 	if (ok)
755 		ok = decode_config1(c);
756 	if (ok)
757 		ok = decode_config2(c);
758 	if (ok)
759 		ok = decode_config3(c);
760 	if (ok)
761 		ok = decode_config4(c);
762 
763 	mips_probe_watch_registers(c);
764 
765 	if (cpu_has_mips_r2)
766 		c->core = read_c0_ebase() & 0x3ff;
767 }
768 
769 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
770 {
771 	decode_configs(c);
772 	switch (c->processor_id & 0xff00) {
773 	case PRID_IMP_4KC:
774 		c->cputype = CPU_4KC;
775 		__cpu_name[cpu] = "MIPS 4Kc";
776 		break;
777 	case PRID_IMP_4KEC:
778 	case PRID_IMP_4KECR2:
779 		c->cputype = CPU_4KEC;
780 		__cpu_name[cpu] = "MIPS 4KEc";
781 		break;
782 	case PRID_IMP_4KSC:
783 	case PRID_IMP_4KSD:
784 		c->cputype = CPU_4KSC;
785 		__cpu_name[cpu] = "MIPS 4KSc";
786 		break;
787 	case PRID_IMP_5KC:
788 		c->cputype = CPU_5KC;
789 		__cpu_name[cpu] = "MIPS 5Kc";
790 		break;
791 	case PRID_IMP_20KC:
792 		c->cputype = CPU_20KC;
793 		__cpu_name[cpu] = "MIPS 20Kc";
794 		break;
795 	case PRID_IMP_24K:
796 	case PRID_IMP_24KE:
797 		c->cputype = CPU_24K;
798 		__cpu_name[cpu] = "MIPS 24Kc";
799 		break;
800 	case PRID_IMP_25KF:
801 		c->cputype = CPU_25KF;
802 		__cpu_name[cpu] = "MIPS 25Kc";
803 		break;
804 	case PRID_IMP_34K:
805 		c->cputype = CPU_34K;
806 		__cpu_name[cpu] = "MIPS 34Kc";
807 		break;
808 	case PRID_IMP_74K:
809 		c->cputype = CPU_74K;
810 		__cpu_name[cpu] = "MIPS 74Kc";
811 		break;
812 	case PRID_IMP_1004K:
813 		c->cputype = CPU_1004K;
814 		__cpu_name[cpu] = "MIPS 1004Kc";
815 		break;
816 	}
817 
818 	spram_config();
819 }
820 
821 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
822 {
823 	decode_configs(c);
824 	switch (c->processor_id & 0xff00) {
825 	case PRID_IMP_AU1_REV1:
826 	case PRID_IMP_AU1_REV2:
827 		c->cputype = CPU_ALCHEMY;
828 		switch ((c->processor_id >> 24) & 0xff) {
829 		case 0:
830 			__cpu_name[cpu] = "Au1000";
831 			break;
832 		case 1:
833 			__cpu_name[cpu] = "Au1500";
834 			break;
835 		case 2:
836 			__cpu_name[cpu] = "Au1100";
837 			break;
838 		case 3:
839 			__cpu_name[cpu] = "Au1550";
840 			break;
841 		case 4:
842 			__cpu_name[cpu] = "Au1200";
843 			if ((c->processor_id & 0xff) == 2)
844 				__cpu_name[cpu] = "Au1250";
845 			break;
846 		case 5:
847 			__cpu_name[cpu] = "Au1210";
848 			break;
849 		default:
850 			__cpu_name[cpu] = "Au1xxx";
851 			break;
852 		}
853 		break;
854 	}
855 }
856 
857 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
858 {
859 	decode_configs(c);
860 
861 	switch (c->processor_id & 0xff00) {
862 	case PRID_IMP_SB1:
863 		c->cputype = CPU_SB1;
864 		__cpu_name[cpu] = "SiByte SB1";
865 		/* FPU in pass1 is known to have issues. */
866 		if ((c->processor_id & 0xff) < 0x02)
867 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
868 		break;
869 	case PRID_IMP_SB1A:
870 		c->cputype = CPU_SB1A;
871 		__cpu_name[cpu] = "SiByte SB1A";
872 		break;
873 	}
874 }
875 
876 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
877 {
878 	decode_configs(c);
879 	switch (c->processor_id & 0xff00) {
880 	case PRID_IMP_SR71000:
881 		c->cputype = CPU_SR71000;
882 		__cpu_name[cpu] = "Sandcraft SR71000";
883 		c->scache.ways = 8;
884 		c->tlbsize = 64;
885 		break;
886 	}
887 }
888 
889 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
890 {
891 	decode_configs(c);
892 	switch (c->processor_id & 0xff00) {
893 	case PRID_IMP_PR4450:
894 		c->cputype = CPU_PR4450;
895 		__cpu_name[cpu] = "Philips PR4450";
896 		c->isa_level = MIPS_CPU_ISA_M32R1;
897 		break;
898 	}
899 }
900 
901 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
902 {
903 	decode_configs(c);
904 	switch (c->processor_id & 0xff00) {
905 	case PRID_IMP_BCM3302:
906 	 /* same as PRID_IMP_BCM6338 */
907 		c->cputype = CPU_BCM3302;
908 		__cpu_name[cpu] = "Broadcom BCM3302";
909 		break;
910 	case PRID_IMP_BCM4710:
911 		c->cputype = CPU_BCM4710;
912 		__cpu_name[cpu] = "Broadcom BCM4710";
913 		break;
914 	case PRID_IMP_BCM6345:
915 		c->cputype = CPU_BCM6345;
916 		__cpu_name[cpu] = "Broadcom BCM6345";
917 		break;
918 	case PRID_IMP_BCM6348:
919 		c->cputype = CPU_BCM6348;
920 		__cpu_name[cpu] = "Broadcom BCM6348";
921 		break;
922 	case PRID_IMP_BCM4350:
923 		switch (c->processor_id & 0xf0) {
924 		case PRID_REV_BCM6358:
925 			c->cputype = CPU_BCM6358;
926 			__cpu_name[cpu] = "Broadcom BCM6358";
927 			break;
928 		default:
929 			c->cputype = CPU_UNKNOWN;
930 			break;
931 		}
932 		break;
933 	}
934 }
935 
936 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
937 {
938 	decode_configs(c);
939 	switch (c->processor_id & 0xff00) {
940 	case PRID_IMP_CAVIUM_CN38XX:
941 	case PRID_IMP_CAVIUM_CN31XX:
942 	case PRID_IMP_CAVIUM_CN30XX:
943 		c->cputype = CPU_CAVIUM_OCTEON;
944 		__cpu_name[cpu] = "Cavium Octeon";
945 		goto platform;
946 	case PRID_IMP_CAVIUM_CN58XX:
947 	case PRID_IMP_CAVIUM_CN56XX:
948 	case PRID_IMP_CAVIUM_CN50XX:
949 	case PRID_IMP_CAVIUM_CN52XX:
950 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
951 		__cpu_name[cpu] = "Cavium Octeon+";
952 platform:
953 		if (cpu == 0)
954 			__elf_platform = "octeon";
955 		break;
956 	default:
957 		printk(KERN_INFO "Unknown Octeon chip!\n");
958 		c->cputype = CPU_UNKNOWN;
959 		break;
960 	}
961 }
962 
963 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
964 {
965 	decode_configs(c);
966 	/* JZRISC does not implement the CP0 counter. */
967 	c->options &= ~MIPS_CPU_COUNTER;
968 	switch (c->processor_id & 0xff00) {
969 	case PRID_IMP_JZRISC:
970 		c->cputype = CPU_JZRISC;
971 		__cpu_name[cpu] = "Ingenic JZRISC";
972 		break;
973 	default:
974 		panic("Unknown Ingenic Processor ID!");
975 		break;
976 	}
977 }
978 
979 const char *__cpu_name[NR_CPUS];
980 const char *__elf_platform;
981 
982 __cpuinit void cpu_probe(void)
983 {
984 	struct cpuinfo_mips *c = &current_cpu_data;
985 	unsigned int cpu = smp_processor_id();
986 
987 	c->processor_id	= PRID_IMP_UNKNOWN;
988 	c->fpu_id	= FPIR_IMP_NONE;
989 	c->cputype	= CPU_UNKNOWN;
990 
991 	c->processor_id = read_c0_prid();
992 	switch (c->processor_id & 0xff0000) {
993 	case PRID_COMP_LEGACY:
994 		cpu_probe_legacy(c, cpu);
995 		break;
996 	case PRID_COMP_MIPS:
997 		cpu_probe_mips(c, cpu);
998 		break;
999 	case PRID_COMP_ALCHEMY:
1000 		cpu_probe_alchemy(c, cpu);
1001 		break;
1002 	case PRID_COMP_SIBYTE:
1003 		cpu_probe_sibyte(c, cpu);
1004 		break;
1005 	case PRID_COMP_BROADCOM:
1006 		cpu_probe_broadcom(c, cpu);
1007 		break;
1008 	case PRID_COMP_SANDCRAFT:
1009 		cpu_probe_sandcraft(c, cpu);
1010 		break;
1011 	case PRID_COMP_NXP:
1012 		cpu_probe_nxp(c, cpu);
1013 		break;
1014 	case PRID_COMP_CAVIUM:
1015 		cpu_probe_cavium(c, cpu);
1016 		break;
1017 	case PRID_COMP_INGENIC:
1018 		cpu_probe_ingenic(c, cpu);
1019 		break;
1020 	}
1021 
1022 	BUG_ON(!__cpu_name[cpu]);
1023 	BUG_ON(c->cputype == CPU_UNKNOWN);
1024 
1025 	/*
1026 	 * Platform code can force the cpu type to optimize code
1027 	 * generation. In that case be sure the cpu type is correctly
1028 	 * manually setup otherwise it could trigger some nasty bugs.
1029 	 */
1030 	BUG_ON(current_cpu_type() != c->cputype);
1031 
1032 	if (mips_fpu_disabled)
1033 		c->options &= ~MIPS_CPU_FPU;
1034 
1035 	if (mips_dsp_disabled)
1036 		c->ases &= ~MIPS_ASE_DSP;
1037 
1038 	if (c->options & MIPS_CPU_FPU) {
1039 		c->fpu_id = cpu_get_fpu_id();
1040 
1041 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1042 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1043 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1044 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1045 			if (c->fpu_id & MIPS_FPIR_3D)
1046 				c->ases |= MIPS_ASE_MIPS3D;
1047 		}
1048 	}
1049 
1050 	if (cpu_has_mips_r2)
1051 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1052 	else
1053 		c->srsets = 1;
1054 
1055 	cpu_probe_vmbits(c);
1056 }
1057 
1058 __cpuinit void cpu_report(void)
1059 {
1060 	struct cpuinfo_mips *c = &current_cpu_data;
1061 
1062 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1063 	       c->processor_id, cpu_name_string());
1064 	if (c->options & MIPS_CPU_FPU)
1065 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1066 }
1067