xref: /linux/arch/mips/kernel/cpu-probe.c (revision 7c43185138cf523b0810ffd2c9e18e2ecb356730)
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 #include <asm/uaccess.h>
29 
30 /*
31  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
32  * the implementation of the "wait" feature differs between CPU families. This
33  * points to the function that implements CPU specific wait.
34  * The wait instruction stops the pipeline and reduces the power consumption of
35  * the CPU very much.
36  */
37 void (*cpu_wait)(void);
38 EXPORT_SYMBOL(cpu_wait);
39 
40 static void r3081_wait(void)
41 {
42 	unsigned long cfg = read_c0_conf();
43 	write_c0_conf(cfg | R30XX_CONF_HALT);
44 }
45 
46 static void r39xx_wait(void)
47 {
48 	local_irq_disable();
49 	if (!need_resched())
50 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
51 	local_irq_enable();
52 }
53 
54 extern void r4k_wait(void);
55 
56 /*
57  * This variant is preferable as it allows testing need_resched and going to
58  * sleep depending on the outcome atomically.  Unfortunately the "It is
59  * implementation-dependent whether the pipeline restarts when a non-enabled
60  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
61  * using this version a gamble.
62  */
63 void r4k_wait_irqoff(void)
64 {
65 	local_irq_disable();
66 	if (!need_resched())
67 		__asm__("	.set	push		\n"
68 			"	.set	mips3		\n"
69 			"	wait			\n"
70 			"	.set	pop		\n");
71 	local_irq_enable();
72 	__asm__(" 	.globl __pastwait	\n"
73 		"__pastwait:			\n");
74 }
75 
76 /*
77  * The RM7000 variant has to handle erratum 38.  The workaround is to not
78  * have any pending stores when the WAIT instruction is executed.
79  */
80 static void rm7k_wait_irqoff(void)
81 {
82 	local_irq_disable();
83 	if (!need_resched())
84 		__asm__(
85 		"	.set	push					\n"
86 		"	.set	mips3					\n"
87 		"	.set	noat					\n"
88 		"	mfc0	$1, $12					\n"
89 		"	sync						\n"
90 		"	mtc0	$1, $12		# stalls until W stage	\n"
91 		"	wait						\n"
92 		"	mtc0	$1, $12		# stalls until W stage	\n"
93 		"	.set	pop					\n");
94 	local_irq_enable();
95 }
96 
97 /*
98  * The Au1xxx wait is available only if using 32khz counter or
99  * external timer source, but specifically not CP0 Counter.
100  * alchemy/common/time.c may override cpu_wait!
101  */
102 static void au1k_wait(void)
103 {
104 	__asm__("	.set	mips3			\n"
105 		"	cache	0x14, 0(%0)		\n"
106 		"	cache	0x14, 32(%0)		\n"
107 		"	sync				\n"
108 		"	nop				\n"
109 		"	wait				\n"
110 		"	nop				\n"
111 		"	nop				\n"
112 		"	nop				\n"
113 		"	nop				\n"
114 		"	.set	mips0			\n"
115 		: : "r" (au1k_wait));
116 }
117 
118 static int __initdata nowait;
119 
120 static int __init wait_disable(char *s)
121 {
122 	nowait = 1;
123 
124 	return 1;
125 }
126 
127 __setup("nowait", wait_disable);
128 
129 static int __cpuinitdata mips_fpu_disabled;
130 
131 static int __init fpu_disable(char *s)
132 {
133 	cpu_data[0].options &= ~MIPS_CPU_FPU;
134 	mips_fpu_disabled = 1;
135 
136 	return 1;
137 }
138 
139 __setup("nofpu", fpu_disable);
140 
141 int __cpuinitdata mips_dsp_disabled;
142 
143 static int __init dsp_disable(char *s)
144 {
145 	cpu_data[0].ases &= ~MIPS_ASE_DSP;
146 	mips_dsp_disabled = 1;
147 
148 	return 1;
149 }
150 
151 __setup("nodsp", dsp_disable);
152 
153 void __init check_wait(void)
154 {
155 	struct cpuinfo_mips *c = &current_cpu_data;
156 
157 	if (nowait) {
158 		printk("Wait instruction disabled.\n");
159 		return;
160 	}
161 
162 	switch (c->cputype) {
163 	case CPU_R3081:
164 	case CPU_R3081E:
165 		cpu_wait = r3081_wait;
166 		break;
167 	case CPU_TX3927:
168 		cpu_wait = r39xx_wait;
169 		break;
170 	case CPU_R4200:
171 /*	case CPU_R4300: */
172 	case CPU_R4600:
173 	case CPU_R4640:
174 	case CPU_R4650:
175 	case CPU_R4700:
176 	case CPU_R5000:
177 	case CPU_R5500:
178 	case CPU_NEVADA:
179 	case CPU_4KC:
180 	case CPU_4KEC:
181 	case CPU_4KSC:
182 	case CPU_5KC:
183 	case CPU_25KF:
184 	case CPU_PR4450:
185 	case CPU_BMIPS3300:
186 	case CPU_BMIPS4350:
187 	case CPU_BMIPS4380:
188 	case CPU_BMIPS5000:
189 	case CPU_CAVIUM_OCTEON:
190 	case CPU_CAVIUM_OCTEON_PLUS:
191 	case CPU_CAVIUM_OCTEON2:
192 	case CPU_JZRISC:
193 		cpu_wait = r4k_wait;
194 		break;
195 
196 	case CPU_RM7000:
197 		cpu_wait = rm7k_wait_irqoff;
198 		break;
199 
200 	case CPU_24K:
201 	case CPU_34K:
202 	case CPU_1004K:
203 		cpu_wait = r4k_wait;
204 		if (read_c0_config7() & MIPS_CONF7_WII)
205 			cpu_wait = r4k_wait_irqoff;
206 		break;
207 
208 	case CPU_74K:
209 		cpu_wait = r4k_wait;
210 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
211 			cpu_wait = r4k_wait_irqoff;
212 		break;
213 
214 	case CPU_TX49XX:
215 		cpu_wait = r4k_wait_irqoff;
216 		break;
217 	case CPU_ALCHEMY:
218 		cpu_wait = au1k_wait;
219 		break;
220 	case CPU_20KC:
221 		/*
222 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
223 		 * WAIT on Rev2.0 and Rev3.0 has E16.
224 		 * Rev3.1 WAIT is nop, why bother
225 		 */
226 		if ((c->processor_id & 0xff) <= 0x64)
227 			break;
228 
229 		/*
230 		 * Another rev is incremeting c0_count at a reduced clock
231 		 * rate while in WAIT mode.  So we basically have the choice
232 		 * between using the cp0 timer as clocksource or avoiding
233 		 * the WAIT instruction.  Until more details are known,
234 		 * disable the use of WAIT for 20Kc entirely.
235 		   cpu_wait = r4k_wait;
236 		 */
237 		break;
238 	case CPU_RM9000:
239 		if ((c->processor_id & 0x00ff) >= 0x40)
240 			cpu_wait = r4k_wait;
241 		break;
242 	default:
243 		break;
244 	}
245 }
246 
247 static inline void check_errata(void)
248 {
249 	struct cpuinfo_mips *c = &current_cpu_data;
250 
251 	switch (c->cputype) {
252 	case CPU_34K:
253 		/*
254 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
255 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
256 		 * making use of VPE1 will be responsable for that VPE.
257 		 */
258 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
259 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
260 		break;
261 	default:
262 		break;
263 	}
264 }
265 
266 void __init check_bugs32(void)
267 {
268 	check_errata();
269 }
270 
271 /*
272  * Probe whether cpu has config register by trying to play with
273  * alternate cache bit and see whether it matters.
274  * It's used by cpu_probe to distinguish between R3000A and R3081.
275  */
276 static inline int cpu_has_confreg(void)
277 {
278 #ifdef CONFIG_CPU_R3000
279 	extern unsigned long r3k_cache_size(unsigned long);
280 	unsigned long size1, size2;
281 	unsigned long cfg = read_c0_conf();
282 
283 	size1 = r3k_cache_size(ST0_ISC);
284 	write_c0_conf(cfg ^ R30XX_CONF_AC);
285 	size2 = r3k_cache_size(ST0_ISC);
286 	write_c0_conf(cfg);
287 	return size1 != size2;
288 #else
289 	return 0;
290 #endif
291 }
292 
293 static inline void set_elf_platform(int cpu, const char *plat)
294 {
295 	if (cpu == 0)
296 		__elf_platform = plat;
297 }
298 
299 /*
300  * Get the FPU Implementation/Revision.
301  */
302 static inline unsigned long cpu_get_fpu_id(void)
303 {
304 	unsigned long tmp, fpu_id;
305 
306 	tmp = read_c0_status();
307 	__enable_fpu();
308 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
309 	write_c0_status(tmp);
310 	return fpu_id;
311 }
312 
313 /*
314  * Check the CPU has an FPU the official way.
315  */
316 static inline int __cpu_has_fpu(void)
317 {
318 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
319 }
320 
321 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
322 {
323 #ifdef __NEED_VMBITS_PROBE
324 	write_c0_entryhi(0x3fffffffffffe000ULL);
325 	back_to_back_c0_hazard();
326 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
327 #endif
328 }
329 
330 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
331 		| MIPS_CPU_COUNTER)
332 
333 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
334 {
335 	switch (c->processor_id & 0xff00) {
336 	case PRID_IMP_R2000:
337 		c->cputype = CPU_R2000;
338 		__cpu_name[cpu] = "R2000";
339 		c->isa_level = MIPS_CPU_ISA_I;
340 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
341 		             MIPS_CPU_NOFPUEX;
342 		if (__cpu_has_fpu())
343 			c->options |= MIPS_CPU_FPU;
344 		c->tlbsize = 64;
345 		break;
346 	case PRID_IMP_R3000:
347 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
348 			if (cpu_has_confreg()) {
349 				c->cputype = CPU_R3081E;
350 				__cpu_name[cpu] = "R3081";
351 			} else {
352 				c->cputype = CPU_R3000A;
353 				__cpu_name[cpu] = "R3000A";
354 			}
355 			break;
356 		} else {
357 			c->cputype = CPU_R3000;
358 			__cpu_name[cpu] = "R3000";
359 		}
360 		c->isa_level = MIPS_CPU_ISA_I;
361 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
362 		             MIPS_CPU_NOFPUEX;
363 		if (__cpu_has_fpu())
364 			c->options |= MIPS_CPU_FPU;
365 		c->tlbsize = 64;
366 		break;
367 	case PRID_IMP_R4000:
368 		if (read_c0_config() & CONF_SC) {
369 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
370 				c->cputype = CPU_R4400PC;
371 				__cpu_name[cpu] = "R4400PC";
372 			} else {
373 				c->cputype = CPU_R4000PC;
374 				__cpu_name[cpu] = "R4000PC";
375 			}
376 		} else {
377 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
378 				c->cputype = CPU_R4400SC;
379 				__cpu_name[cpu] = "R4400SC";
380 			} else {
381 				c->cputype = CPU_R4000SC;
382 				__cpu_name[cpu] = "R4000SC";
383 			}
384 		}
385 
386 		c->isa_level = MIPS_CPU_ISA_III;
387 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
388 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
389 		             MIPS_CPU_LLSC;
390 		c->tlbsize = 48;
391 		break;
392 	case PRID_IMP_VR41XX:
393 		switch (c->processor_id & 0xf0) {
394 		case PRID_REV_VR4111:
395 			c->cputype = CPU_VR4111;
396 			__cpu_name[cpu] = "NEC VR4111";
397 			break;
398 		case PRID_REV_VR4121:
399 			c->cputype = CPU_VR4121;
400 			__cpu_name[cpu] = "NEC VR4121";
401 			break;
402 		case PRID_REV_VR4122:
403 			if ((c->processor_id & 0xf) < 0x3) {
404 				c->cputype = CPU_VR4122;
405 				__cpu_name[cpu] = "NEC VR4122";
406 			} else {
407 				c->cputype = CPU_VR4181A;
408 				__cpu_name[cpu] = "NEC VR4181A";
409 			}
410 			break;
411 		case PRID_REV_VR4130:
412 			if ((c->processor_id & 0xf) < 0x4) {
413 				c->cputype = CPU_VR4131;
414 				__cpu_name[cpu] = "NEC VR4131";
415 			} else {
416 				c->cputype = CPU_VR4133;
417 				__cpu_name[cpu] = "NEC VR4133";
418 			}
419 			break;
420 		default:
421 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
422 			c->cputype = CPU_VR41XX;
423 			__cpu_name[cpu] = "NEC Vr41xx";
424 			break;
425 		}
426 		c->isa_level = MIPS_CPU_ISA_III;
427 		c->options = R4K_OPTS;
428 		c->tlbsize = 32;
429 		break;
430 	case PRID_IMP_R4300:
431 		c->cputype = CPU_R4300;
432 		__cpu_name[cpu] = "R4300";
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 = 32;
437 		break;
438 	case PRID_IMP_R4600:
439 		c->cputype = CPU_R4600;
440 		__cpu_name[cpu] = "R4600";
441 		c->isa_level = MIPS_CPU_ISA_III;
442 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
443 			     MIPS_CPU_LLSC;
444 		c->tlbsize = 48;
445 		break;
446 	#if 0
447  	case PRID_IMP_R4650:
448 		/*
449 		 * This processor doesn't have an MMU, so it's not
450 		 * "real easy" to run Linux on it. It is left purely
451 		 * for documentation.  Commented out because it shares
452 		 * it's c0_prid id number with the TX3900.
453 		 */
454 		c->cputype = CPU_R4650;
455 		__cpu_name[cpu] = "R4650";
456 	 	c->isa_level = MIPS_CPU_ISA_III;
457 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
458 	        c->tlbsize = 48;
459 		break;
460 	#endif
461 	case PRID_IMP_TX39:
462 		c->isa_level = MIPS_CPU_ISA_I;
463 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
464 
465 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
466 			c->cputype = CPU_TX3927;
467 			__cpu_name[cpu] = "TX3927";
468 			c->tlbsize = 64;
469 		} else {
470 			switch (c->processor_id & 0xff) {
471 			case PRID_REV_TX3912:
472 				c->cputype = CPU_TX3912;
473 				__cpu_name[cpu] = "TX3912";
474 				c->tlbsize = 32;
475 				break;
476 			case PRID_REV_TX3922:
477 				c->cputype = CPU_TX3922;
478 				__cpu_name[cpu] = "TX3922";
479 				c->tlbsize = 64;
480 				break;
481 			}
482 		}
483 		break;
484 	case PRID_IMP_R4700:
485 		c->cputype = CPU_R4700;
486 		__cpu_name[cpu] = "R4700";
487 		c->isa_level = MIPS_CPU_ISA_III;
488 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
489 		             MIPS_CPU_LLSC;
490 		c->tlbsize = 48;
491 		break;
492 	case PRID_IMP_TX49:
493 		c->cputype = CPU_TX49XX;
494 		__cpu_name[cpu] = "R49XX";
495 		c->isa_level = MIPS_CPU_ISA_III;
496 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
497 		if (!(c->processor_id & 0x08))
498 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
499 		c->tlbsize = 48;
500 		break;
501 	case PRID_IMP_R5000:
502 		c->cputype = CPU_R5000;
503 		__cpu_name[cpu] = "R5000";
504 		c->isa_level = MIPS_CPU_ISA_IV;
505 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
506 		             MIPS_CPU_LLSC;
507 		c->tlbsize = 48;
508 		break;
509 	case PRID_IMP_R5432:
510 		c->cputype = CPU_R5432;
511 		__cpu_name[cpu] = "R5432";
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_R5500:
518 		c->cputype = CPU_R5500;
519 		__cpu_name[cpu] = "R5500";
520 		c->isa_level = MIPS_CPU_ISA_IV;
521 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
522 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
523 		c->tlbsize = 48;
524 		break;
525 	case PRID_IMP_NEVADA:
526 		c->cputype = CPU_NEVADA;
527 		__cpu_name[cpu] = "Nevada";
528 		c->isa_level = MIPS_CPU_ISA_IV;
529 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
530 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
531 		c->tlbsize = 48;
532 		break;
533 	case PRID_IMP_R6000:
534 		c->cputype = CPU_R6000;
535 		__cpu_name[cpu] = "R6000";
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_R6000A:
542 		c->cputype = CPU_R6000A;
543 		__cpu_name[cpu] = "R6000A";
544 		c->isa_level = MIPS_CPU_ISA_II;
545 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
546 		             MIPS_CPU_LLSC;
547 		c->tlbsize = 32;
548 		break;
549 	case PRID_IMP_RM7000:
550 		c->cputype = CPU_RM7000;
551 		__cpu_name[cpu] = "RM7000";
552 		c->isa_level = MIPS_CPU_ISA_IV;
553 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
554 		             MIPS_CPU_LLSC;
555 		/*
556 		 * Undocumented RM7000:  Bit 29 in the info register of
557 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
558 		 * entries.
559 		 *
560 		 * 29      1 =>    64 entry JTLB
561 		 *         0 =>    48 entry JTLB
562 		 */
563 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
564 		break;
565 	case PRID_IMP_RM9000:
566 		c->cputype = CPU_RM9000;
567 		__cpu_name[cpu] = "RM9000";
568 		c->isa_level = MIPS_CPU_ISA_IV;
569 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
570 		             MIPS_CPU_LLSC;
571 		/*
572 		 * Bit 29 in the info register of the RM9000
573 		 * indicates if the TLB has 48 or 64 entries.
574 		 *
575 		 * 29      1 =>    64 entry JTLB
576 		 *         0 =>    48 entry JTLB
577 		 */
578 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
579 		break;
580 	case PRID_IMP_R8000:
581 		c->cputype = CPU_R8000;
582 		__cpu_name[cpu] = "RM8000";
583 		c->isa_level = MIPS_CPU_ISA_IV;
584 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
585 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
586 		             MIPS_CPU_LLSC;
587 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
588 		break;
589 	case PRID_IMP_R10000:
590 		c->cputype = CPU_R10000;
591 		__cpu_name[cpu] = "R10000";
592 		c->isa_level = MIPS_CPU_ISA_IV;
593 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
594 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
595 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
596 		             MIPS_CPU_LLSC;
597 		c->tlbsize = 64;
598 		break;
599 	case PRID_IMP_R12000:
600 		c->cputype = CPU_R12000;
601 		__cpu_name[cpu] = "R12000";
602 		c->isa_level = MIPS_CPU_ISA_IV;
603 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
604 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
605 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
606 		             MIPS_CPU_LLSC;
607 		c->tlbsize = 64;
608 		break;
609 	case PRID_IMP_R14000:
610 		c->cputype = CPU_R14000;
611 		__cpu_name[cpu] = "R14000";
612 		c->isa_level = MIPS_CPU_ISA_IV;
613 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
614 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
615 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
616 		             MIPS_CPU_LLSC;
617 		c->tlbsize = 64;
618 		break;
619 	case PRID_IMP_LOONGSON2:
620 		c->cputype = CPU_LOONGSON2;
621 		__cpu_name[cpu] = "ICT Loongson-2";
622 
623 		switch (c->processor_id & PRID_REV_MASK) {
624 		case PRID_REV_LOONGSON2E:
625 			set_elf_platform(cpu, "loongson2e");
626 			break;
627 		case PRID_REV_LOONGSON2F:
628 			set_elf_platform(cpu, "loongson2f");
629 			break;
630 		}
631 
632 		c->isa_level = MIPS_CPU_ISA_III;
633 		c->options = R4K_OPTS |
634 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
635 			     MIPS_CPU_32FPR;
636 		c->tlbsize = 64;
637 		break;
638 	}
639 }
640 
641 static char unknown_isa[] __cpuinitdata = KERN_ERR \
642 	"Unsupported ISA type, c0.config0: %d.";
643 
644 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
645 {
646 	unsigned int config0;
647 	int isa;
648 
649 	config0 = read_c0_config();
650 
651 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
652 		c->options |= MIPS_CPU_TLB;
653 	isa = (config0 & MIPS_CONF_AT) >> 13;
654 	switch (isa) {
655 	case 0:
656 		switch ((config0 & MIPS_CONF_AR) >> 10) {
657 		case 0:
658 			c->isa_level = MIPS_CPU_ISA_M32R1;
659 			break;
660 		case 1:
661 			c->isa_level = MIPS_CPU_ISA_M32R2;
662 			break;
663 		default:
664 			goto unknown;
665 		}
666 		break;
667 	case 2:
668 		switch ((config0 & MIPS_CONF_AR) >> 10) {
669 		case 0:
670 			c->isa_level = MIPS_CPU_ISA_M64R1;
671 			break;
672 		case 1:
673 			c->isa_level = MIPS_CPU_ISA_M64R2;
674 			break;
675 		default:
676 			goto unknown;
677 		}
678 		break;
679 	default:
680 		goto unknown;
681 	}
682 
683 	return config0 & MIPS_CONF_M;
684 
685 unknown:
686 	panic(unknown_isa, config0);
687 }
688 
689 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
690 {
691 	unsigned int config1;
692 
693 	config1 = read_c0_config1();
694 
695 	if (config1 & MIPS_CONF1_MD)
696 		c->ases |= MIPS_ASE_MDMX;
697 	if (config1 & MIPS_CONF1_WR)
698 		c->options |= MIPS_CPU_WATCH;
699 	if (config1 & MIPS_CONF1_CA)
700 		c->ases |= MIPS_ASE_MIPS16;
701 	if (config1 & MIPS_CONF1_EP)
702 		c->options |= MIPS_CPU_EJTAG;
703 	if (config1 & MIPS_CONF1_FP) {
704 		c->options |= MIPS_CPU_FPU;
705 		c->options |= MIPS_CPU_32FPR;
706 	}
707 	if (cpu_has_tlb)
708 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
709 
710 	return config1 & MIPS_CONF_M;
711 }
712 
713 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
714 {
715 	unsigned int config2;
716 
717 	config2 = read_c0_config2();
718 
719 	if (config2 & MIPS_CONF2_SL)
720 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
721 
722 	return config2 & MIPS_CONF_M;
723 }
724 
725 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
726 {
727 	unsigned int config3;
728 
729 	config3 = read_c0_config3();
730 
731 	if (config3 & MIPS_CONF3_SM)
732 		c->ases |= MIPS_ASE_SMARTMIPS;
733 	if (config3 & MIPS_CONF3_DSP)
734 		c->ases |= MIPS_ASE_DSP;
735 	if (config3 & MIPS_CONF3_VINT)
736 		c->options |= MIPS_CPU_VINT;
737 	if (config3 & MIPS_CONF3_VEIC)
738 		c->options |= MIPS_CPU_VEIC;
739 	if (config3 & MIPS_CONF3_MT)
740 	        c->ases |= MIPS_ASE_MIPSMT;
741 	if (config3 & MIPS_CONF3_ULRI)
742 		c->options |= MIPS_CPU_ULRI;
743 
744 	return config3 & MIPS_CONF_M;
745 }
746 
747 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
748 {
749 	unsigned int config4;
750 
751 	config4 = read_c0_config4();
752 
753 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
754 	    && cpu_has_tlb)
755 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
756 
757 	c->kscratch_mask = (config4 >> 16) & 0xff;
758 
759 	return config4 & MIPS_CONF_M;
760 }
761 
762 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
763 {
764 	int ok;
765 
766 	/* MIPS32 or MIPS64 compliant CPU.  */
767 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
768 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
769 
770 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
771 
772 	ok = decode_config0(c);			/* Read Config registers.  */
773 	BUG_ON(!ok);				/* Arch spec violation!  */
774 	if (ok)
775 		ok = decode_config1(c);
776 	if (ok)
777 		ok = decode_config2(c);
778 	if (ok)
779 		ok = decode_config3(c);
780 	if (ok)
781 		ok = decode_config4(c);
782 
783 	mips_probe_watch_registers(c);
784 
785 	if (cpu_has_mips_r2)
786 		c->core = read_c0_ebase() & 0x3ff;
787 }
788 
789 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
790 {
791 	decode_configs(c);
792 	switch (c->processor_id & 0xff00) {
793 	case PRID_IMP_4KC:
794 		c->cputype = CPU_4KC;
795 		__cpu_name[cpu] = "MIPS 4Kc";
796 		break;
797 	case PRID_IMP_4KEC:
798 	case PRID_IMP_4KECR2:
799 		c->cputype = CPU_4KEC;
800 		__cpu_name[cpu] = "MIPS 4KEc";
801 		break;
802 	case PRID_IMP_4KSC:
803 	case PRID_IMP_4KSD:
804 		c->cputype = CPU_4KSC;
805 		__cpu_name[cpu] = "MIPS 4KSc";
806 		break;
807 	case PRID_IMP_5KC:
808 		c->cputype = CPU_5KC;
809 		__cpu_name[cpu] = "MIPS 5Kc";
810 		break;
811 	case PRID_IMP_20KC:
812 		c->cputype = CPU_20KC;
813 		__cpu_name[cpu] = "MIPS 20Kc";
814 		break;
815 	case PRID_IMP_24K:
816 	case PRID_IMP_24KE:
817 		c->cputype = CPU_24K;
818 		__cpu_name[cpu] = "MIPS 24Kc";
819 		break;
820 	case PRID_IMP_25KF:
821 		c->cputype = CPU_25KF;
822 		__cpu_name[cpu] = "MIPS 25Kc";
823 		break;
824 	case PRID_IMP_34K:
825 		c->cputype = CPU_34K;
826 		__cpu_name[cpu] = "MIPS 34Kc";
827 		break;
828 	case PRID_IMP_74K:
829 		c->cputype = CPU_74K;
830 		__cpu_name[cpu] = "MIPS 74Kc";
831 		break;
832 	case PRID_IMP_1004K:
833 		c->cputype = CPU_1004K;
834 		__cpu_name[cpu] = "MIPS 1004Kc";
835 		break;
836 	}
837 
838 	spram_config();
839 }
840 
841 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
842 {
843 	decode_configs(c);
844 	switch (c->processor_id & 0xff00) {
845 	case PRID_IMP_AU1_REV1:
846 	case PRID_IMP_AU1_REV2:
847 		c->cputype = CPU_ALCHEMY;
848 		switch ((c->processor_id >> 24) & 0xff) {
849 		case 0:
850 			__cpu_name[cpu] = "Au1000";
851 			break;
852 		case 1:
853 			__cpu_name[cpu] = "Au1500";
854 			break;
855 		case 2:
856 			__cpu_name[cpu] = "Au1100";
857 			break;
858 		case 3:
859 			__cpu_name[cpu] = "Au1550";
860 			break;
861 		case 4:
862 			__cpu_name[cpu] = "Au1200";
863 			if ((c->processor_id & 0xff) == 2)
864 				__cpu_name[cpu] = "Au1250";
865 			break;
866 		case 5:
867 			__cpu_name[cpu] = "Au1210";
868 			break;
869 		default:
870 			__cpu_name[cpu] = "Au1xxx";
871 			break;
872 		}
873 		break;
874 	}
875 }
876 
877 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
878 {
879 	decode_configs(c);
880 
881 	switch (c->processor_id & 0xff00) {
882 	case PRID_IMP_SB1:
883 		c->cputype = CPU_SB1;
884 		__cpu_name[cpu] = "SiByte SB1";
885 		/* FPU in pass1 is known to have issues. */
886 		if ((c->processor_id & 0xff) < 0x02)
887 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
888 		break;
889 	case PRID_IMP_SB1A:
890 		c->cputype = CPU_SB1A;
891 		__cpu_name[cpu] = "SiByte SB1A";
892 		break;
893 	}
894 }
895 
896 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
897 {
898 	decode_configs(c);
899 	switch (c->processor_id & 0xff00) {
900 	case PRID_IMP_SR71000:
901 		c->cputype = CPU_SR71000;
902 		__cpu_name[cpu] = "Sandcraft SR71000";
903 		c->scache.ways = 8;
904 		c->tlbsize = 64;
905 		break;
906 	}
907 }
908 
909 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
910 {
911 	decode_configs(c);
912 	switch (c->processor_id & 0xff00) {
913 	case PRID_IMP_PR4450:
914 		c->cputype = CPU_PR4450;
915 		__cpu_name[cpu] = "Philips PR4450";
916 		c->isa_level = MIPS_CPU_ISA_M32R1;
917 		break;
918 	}
919 }
920 
921 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
922 {
923 	decode_configs(c);
924 	switch (c->processor_id & 0xff00) {
925 	case PRID_IMP_BMIPS32_REV4:
926 	case PRID_IMP_BMIPS32_REV8:
927 		c->cputype = CPU_BMIPS32;
928 		__cpu_name[cpu] = "Broadcom BMIPS32";
929 		set_elf_platform(cpu, "bmips32");
930 		break;
931 	case PRID_IMP_BMIPS3300:
932 	case PRID_IMP_BMIPS3300_ALT:
933 	case PRID_IMP_BMIPS3300_BUG:
934 		c->cputype = CPU_BMIPS3300;
935 		__cpu_name[cpu] = "Broadcom BMIPS3300";
936 		set_elf_platform(cpu, "bmips3300");
937 		break;
938 	case PRID_IMP_BMIPS43XX: {
939 		int rev = c->processor_id & 0xff;
940 
941 		if (rev >= PRID_REV_BMIPS4380_LO &&
942 				rev <= PRID_REV_BMIPS4380_HI) {
943 			c->cputype = CPU_BMIPS4380;
944 			__cpu_name[cpu] = "Broadcom BMIPS4380";
945 			set_elf_platform(cpu, "bmips4380");
946 		} else {
947 			c->cputype = CPU_BMIPS4350;
948 			__cpu_name[cpu] = "Broadcom BMIPS4350";
949 			set_elf_platform(cpu, "bmips4350");
950 		}
951 		break;
952 	}
953 	case PRID_IMP_BMIPS5000:
954 		c->cputype = CPU_BMIPS5000;
955 		__cpu_name[cpu] = "Broadcom BMIPS5000";
956 		set_elf_platform(cpu, "bmips5000");
957 		c->options |= MIPS_CPU_ULRI;
958 		break;
959 	}
960 }
961 
962 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
963 {
964 	decode_configs(c);
965 	switch (c->processor_id & 0xff00) {
966 	case PRID_IMP_CAVIUM_CN38XX:
967 	case PRID_IMP_CAVIUM_CN31XX:
968 	case PRID_IMP_CAVIUM_CN30XX:
969 		c->cputype = CPU_CAVIUM_OCTEON;
970 		__cpu_name[cpu] = "Cavium Octeon";
971 		goto platform;
972 	case PRID_IMP_CAVIUM_CN58XX:
973 	case PRID_IMP_CAVIUM_CN56XX:
974 	case PRID_IMP_CAVIUM_CN50XX:
975 	case PRID_IMP_CAVIUM_CN52XX:
976 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
977 		__cpu_name[cpu] = "Cavium Octeon+";
978 platform:
979 		set_elf_platform(cpu, "octeon");
980 		break;
981 	case PRID_IMP_CAVIUM_CN63XX:
982 		c->cputype = CPU_CAVIUM_OCTEON2;
983 		__cpu_name[cpu] = "Cavium Octeon II";
984 		set_elf_platform(cpu, "octeon2");
985 		break;
986 	default:
987 		printk(KERN_INFO "Unknown Octeon chip!\n");
988 		c->cputype = CPU_UNKNOWN;
989 		break;
990 	}
991 }
992 
993 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
994 {
995 	decode_configs(c);
996 	/* JZRISC does not implement the CP0 counter. */
997 	c->options &= ~MIPS_CPU_COUNTER;
998 	switch (c->processor_id & 0xff00) {
999 	case PRID_IMP_JZRISC:
1000 		c->cputype = CPU_JZRISC;
1001 		__cpu_name[cpu] = "Ingenic JZRISC";
1002 		break;
1003 	default:
1004 		panic("Unknown Ingenic Processor ID!");
1005 		break;
1006 	}
1007 }
1008 
1009 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1010 {
1011 	decode_configs(c);
1012 
1013 	c->options = (MIPS_CPU_TLB       |
1014 			MIPS_CPU_4KEX    |
1015 			MIPS_CPU_COUNTER |
1016 			MIPS_CPU_DIVEC   |
1017 			MIPS_CPU_WATCH   |
1018 			MIPS_CPU_EJTAG   |
1019 			MIPS_CPU_LLSC);
1020 
1021 	switch (c->processor_id & 0xff00) {
1022 	case PRID_IMP_NETLOGIC_XLR732:
1023 	case PRID_IMP_NETLOGIC_XLR716:
1024 	case PRID_IMP_NETLOGIC_XLR532:
1025 	case PRID_IMP_NETLOGIC_XLR308:
1026 	case PRID_IMP_NETLOGIC_XLR532C:
1027 	case PRID_IMP_NETLOGIC_XLR516C:
1028 	case PRID_IMP_NETLOGIC_XLR508C:
1029 	case PRID_IMP_NETLOGIC_XLR308C:
1030 		c->cputype = CPU_XLR;
1031 		__cpu_name[cpu] = "Netlogic XLR";
1032 		break;
1033 
1034 	case PRID_IMP_NETLOGIC_XLS608:
1035 	case PRID_IMP_NETLOGIC_XLS408:
1036 	case PRID_IMP_NETLOGIC_XLS404:
1037 	case PRID_IMP_NETLOGIC_XLS208:
1038 	case PRID_IMP_NETLOGIC_XLS204:
1039 	case PRID_IMP_NETLOGIC_XLS108:
1040 	case PRID_IMP_NETLOGIC_XLS104:
1041 	case PRID_IMP_NETLOGIC_XLS616B:
1042 	case PRID_IMP_NETLOGIC_XLS608B:
1043 	case PRID_IMP_NETLOGIC_XLS416B:
1044 	case PRID_IMP_NETLOGIC_XLS412B:
1045 	case PRID_IMP_NETLOGIC_XLS408B:
1046 	case PRID_IMP_NETLOGIC_XLS404B:
1047 		c->cputype = CPU_XLR;
1048 		__cpu_name[cpu] = "Netlogic XLS";
1049 		break;
1050 
1051 	default:
1052 		printk(KERN_INFO "Unknown Netlogic chip id [%02x]!\n",
1053 		       c->processor_id);
1054 		c->cputype = CPU_XLR;
1055 		break;
1056 	}
1057 
1058 	c->isa_level = MIPS_CPU_ISA_M64R1;
1059 	c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
1060 }
1061 
1062 #ifdef CONFIG_64BIT
1063 /* For use by uaccess.h */
1064 u64 __ua_limit;
1065 EXPORT_SYMBOL(__ua_limit);
1066 #endif
1067 
1068 const char *__cpu_name[NR_CPUS];
1069 const char *__elf_platform;
1070 
1071 __cpuinit void cpu_probe(void)
1072 {
1073 	struct cpuinfo_mips *c = &current_cpu_data;
1074 	unsigned int cpu = smp_processor_id();
1075 
1076 	c->processor_id	= PRID_IMP_UNKNOWN;
1077 	c->fpu_id	= FPIR_IMP_NONE;
1078 	c->cputype	= CPU_UNKNOWN;
1079 
1080 	c->processor_id = read_c0_prid();
1081 	switch (c->processor_id & 0xff0000) {
1082 	case PRID_COMP_LEGACY:
1083 		cpu_probe_legacy(c, cpu);
1084 		break;
1085 	case PRID_COMP_MIPS:
1086 		cpu_probe_mips(c, cpu);
1087 		break;
1088 	case PRID_COMP_ALCHEMY:
1089 		cpu_probe_alchemy(c, cpu);
1090 		break;
1091 	case PRID_COMP_SIBYTE:
1092 		cpu_probe_sibyte(c, cpu);
1093 		break;
1094 	case PRID_COMP_BROADCOM:
1095 		cpu_probe_broadcom(c, cpu);
1096 		break;
1097 	case PRID_COMP_SANDCRAFT:
1098 		cpu_probe_sandcraft(c, cpu);
1099 		break;
1100 	case PRID_COMP_NXP:
1101 		cpu_probe_nxp(c, cpu);
1102 		break;
1103 	case PRID_COMP_CAVIUM:
1104 		cpu_probe_cavium(c, cpu);
1105 		break;
1106 	case PRID_COMP_INGENIC:
1107 		cpu_probe_ingenic(c, cpu);
1108 		break;
1109 	case PRID_COMP_NETLOGIC:
1110 		cpu_probe_netlogic(c, cpu);
1111 		break;
1112 	}
1113 
1114 	BUG_ON(!__cpu_name[cpu]);
1115 	BUG_ON(c->cputype == CPU_UNKNOWN);
1116 
1117 	/*
1118 	 * Platform code can force the cpu type to optimize code
1119 	 * generation. In that case be sure the cpu type is correctly
1120 	 * manually setup otherwise it could trigger some nasty bugs.
1121 	 */
1122 	BUG_ON(current_cpu_type() != c->cputype);
1123 
1124 	if (mips_fpu_disabled)
1125 		c->options &= ~MIPS_CPU_FPU;
1126 
1127 	if (mips_dsp_disabled)
1128 		c->ases &= ~MIPS_ASE_DSP;
1129 
1130 	if (c->options & MIPS_CPU_FPU) {
1131 		c->fpu_id = cpu_get_fpu_id();
1132 
1133 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1134 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1135 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1136 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1137 			if (c->fpu_id & MIPS_FPIR_3D)
1138 				c->ases |= MIPS_ASE_MIPS3D;
1139 		}
1140 	}
1141 
1142 	if (cpu_has_mips_r2)
1143 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1144 	else
1145 		c->srsets = 1;
1146 
1147 	cpu_probe_vmbits(c);
1148 
1149 #ifdef CONFIG_64BIT
1150 	if (cpu == 0)
1151 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
1152 #endif
1153 }
1154 
1155 __cpuinit void cpu_report(void)
1156 {
1157 	struct cpuinfo_mips *c = &current_cpu_data;
1158 
1159 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1160 	       c->processor_id, cpu_name_string());
1161 	if (c->options & MIPS_CPU_FPU)
1162 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1163 }
1164