xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 63dc02bd)
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/export.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/watch.h>
26 #include <asm/elf.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 	case CPU_XLR:
194 	case CPU_XLP:
195 		cpu_wait = r4k_wait;
196 		break;
197 
198 	case CPU_RM7000:
199 		cpu_wait = rm7k_wait_irqoff;
200 		break;
201 
202 	case CPU_24K:
203 	case CPU_34K:
204 	case CPU_1004K:
205 		cpu_wait = r4k_wait;
206 		if (read_c0_config7() & MIPS_CONF7_WII)
207 			cpu_wait = r4k_wait_irqoff;
208 		break;
209 
210 	case CPU_74K:
211 		cpu_wait = r4k_wait;
212 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
213 			cpu_wait = r4k_wait_irqoff;
214 		break;
215 
216 	case CPU_TX49XX:
217 		cpu_wait = r4k_wait_irqoff;
218 		break;
219 	case CPU_ALCHEMY:
220 		cpu_wait = au1k_wait;
221 		break;
222 	case CPU_20KC:
223 		/*
224 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
225 		 * WAIT on Rev2.0 and Rev3.0 has E16.
226 		 * Rev3.1 WAIT is nop, why bother
227 		 */
228 		if ((c->processor_id & 0xff) <= 0x64)
229 			break;
230 
231 		/*
232 		 * Another rev is incremeting c0_count at a reduced clock
233 		 * rate while in WAIT mode.  So we basically have the choice
234 		 * between using the cp0 timer as clocksource or avoiding
235 		 * the WAIT instruction.  Until more details are known,
236 		 * disable the use of WAIT for 20Kc entirely.
237 		   cpu_wait = r4k_wait;
238 		 */
239 		break;
240 	case CPU_RM9000:
241 		if ((c->processor_id & 0x00ff) >= 0x40)
242 			cpu_wait = r4k_wait;
243 		break;
244 	default:
245 		break;
246 	}
247 }
248 
249 static inline void check_errata(void)
250 {
251 	struct cpuinfo_mips *c = &current_cpu_data;
252 
253 	switch (c->cputype) {
254 	case CPU_34K:
255 		/*
256 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
257 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
258 		 * making use of VPE1 will be responsable for that VPE.
259 		 */
260 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
261 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
262 		break;
263 	default:
264 		break;
265 	}
266 }
267 
268 void __init check_bugs32(void)
269 {
270 	check_errata();
271 }
272 
273 /*
274  * Probe whether cpu has config register by trying to play with
275  * alternate cache bit and see whether it matters.
276  * It's used by cpu_probe to distinguish between R3000A and R3081.
277  */
278 static inline int cpu_has_confreg(void)
279 {
280 #ifdef CONFIG_CPU_R3000
281 	extern unsigned long r3k_cache_size(unsigned long);
282 	unsigned long size1, size2;
283 	unsigned long cfg = read_c0_conf();
284 
285 	size1 = r3k_cache_size(ST0_ISC);
286 	write_c0_conf(cfg ^ R30XX_CONF_AC);
287 	size2 = r3k_cache_size(ST0_ISC);
288 	write_c0_conf(cfg);
289 	return size1 != size2;
290 #else
291 	return 0;
292 #endif
293 }
294 
295 static inline void set_elf_platform(int cpu, const char *plat)
296 {
297 	if (cpu == 0)
298 		__elf_platform = plat;
299 }
300 
301 /*
302  * Get the FPU Implementation/Revision.
303  */
304 static inline unsigned long cpu_get_fpu_id(void)
305 {
306 	unsigned long tmp, fpu_id;
307 
308 	tmp = read_c0_status();
309 	__enable_fpu();
310 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
311 	write_c0_status(tmp);
312 	return fpu_id;
313 }
314 
315 /*
316  * Check the CPU has an FPU the official way.
317  */
318 static inline int __cpu_has_fpu(void)
319 {
320 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
321 }
322 
323 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
324 {
325 #ifdef __NEED_VMBITS_PROBE
326 	write_c0_entryhi(0x3fffffffffffe000ULL);
327 	back_to_back_c0_hazard();
328 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
329 #endif
330 }
331 
332 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
333 		| MIPS_CPU_COUNTER)
334 
335 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
336 {
337 	switch (c->processor_id & 0xff00) {
338 	case PRID_IMP_R2000:
339 		c->cputype = CPU_R2000;
340 		__cpu_name[cpu] = "R2000";
341 		c->isa_level = MIPS_CPU_ISA_I;
342 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
343 		             MIPS_CPU_NOFPUEX;
344 		if (__cpu_has_fpu())
345 			c->options |= MIPS_CPU_FPU;
346 		c->tlbsize = 64;
347 		break;
348 	case PRID_IMP_R3000:
349 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
350 			if (cpu_has_confreg()) {
351 				c->cputype = CPU_R3081E;
352 				__cpu_name[cpu] = "R3081";
353 			} else {
354 				c->cputype = CPU_R3000A;
355 				__cpu_name[cpu] = "R3000A";
356 			}
357 			break;
358 		} else {
359 			c->cputype = CPU_R3000;
360 			__cpu_name[cpu] = "R3000";
361 		}
362 		c->isa_level = MIPS_CPU_ISA_I;
363 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
364 		             MIPS_CPU_NOFPUEX;
365 		if (__cpu_has_fpu())
366 			c->options |= MIPS_CPU_FPU;
367 		c->tlbsize = 64;
368 		break;
369 	case PRID_IMP_R4000:
370 		if (read_c0_config() & CONF_SC) {
371 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
372 				c->cputype = CPU_R4400PC;
373 				__cpu_name[cpu] = "R4400PC";
374 			} else {
375 				c->cputype = CPU_R4000PC;
376 				__cpu_name[cpu] = "R4000PC";
377 			}
378 		} else {
379 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
380 				c->cputype = CPU_R4400SC;
381 				__cpu_name[cpu] = "R4400SC";
382 			} else {
383 				c->cputype = CPU_R4000SC;
384 				__cpu_name[cpu] = "R4000SC";
385 			}
386 		}
387 
388 		c->isa_level = MIPS_CPU_ISA_III;
389 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
390 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
391 		             MIPS_CPU_LLSC;
392 		c->tlbsize = 48;
393 		break;
394 	case PRID_IMP_VR41XX:
395 		switch (c->processor_id & 0xf0) {
396 		case PRID_REV_VR4111:
397 			c->cputype = CPU_VR4111;
398 			__cpu_name[cpu] = "NEC VR4111";
399 			break;
400 		case PRID_REV_VR4121:
401 			c->cputype = CPU_VR4121;
402 			__cpu_name[cpu] = "NEC VR4121";
403 			break;
404 		case PRID_REV_VR4122:
405 			if ((c->processor_id & 0xf) < 0x3) {
406 				c->cputype = CPU_VR4122;
407 				__cpu_name[cpu] = "NEC VR4122";
408 			} else {
409 				c->cputype = CPU_VR4181A;
410 				__cpu_name[cpu] = "NEC VR4181A";
411 			}
412 			break;
413 		case PRID_REV_VR4130:
414 			if ((c->processor_id & 0xf) < 0x4) {
415 				c->cputype = CPU_VR4131;
416 				__cpu_name[cpu] = "NEC VR4131";
417 			} else {
418 				c->cputype = CPU_VR4133;
419 				__cpu_name[cpu] = "NEC VR4133";
420 			}
421 			break;
422 		default:
423 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
424 			c->cputype = CPU_VR41XX;
425 			__cpu_name[cpu] = "NEC Vr41xx";
426 			break;
427 		}
428 		c->isa_level = MIPS_CPU_ISA_III;
429 		c->options = R4K_OPTS;
430 		c->tlbsize = 32;
431 		break;
432 	case PRID_IMP_R4300:
433 		c->cputype = CPU_R4300;
434 		__cpu_name[cpu] = "R4300";
435 		c->isa_level = MIPS_CPU_ISA_III;
436 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
437 		             MIPS_CPU_LLSC;
438 		c->tlbsize = 32;
439 		break;
440 	case PRID_IMP_R4600:
441 		c->cputype = CPU_R4600;
442 		__cpu_name[cpu] = "R4600";
443 		c->isa_level = MIPS_CPU_ISA_III;
444 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
445 			     MIPS_CPU_LLSC;
446 		c->tlbsize = 48;
447 		break;
448 	#if 0
449  	case PRID_IMP_R4650:
450 		/*
451 		 * This processor doesn't have an MMU, so it's not
452 		 * "real easy" to run Linux on it. It is left purely
453 		 * for documentation.  Commented out because it shares
454 		 * it's c0_prid id number with the TX3900.
455 		 */
456 		c->cputype = CPU_R4650;
457 		__cpu_name[cpu] = "R4650";
458 	 	c->isa_level = MIPS_CPU_ISA_III;
459 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
460 	        c->tlbsize = 48;
461 		break;
462 	#endif
463 	case PRID_IMP_TX39:
464 		c->isa_level = MIPS_CPU_ISA_I;
465 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
466 
467 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
468 			c->cputype = CPU_TX3927;
469 			__cpu_name[cpu] = "TX3927";
470 			c->tlbsize = 64;
471 		} else {
472 			switch (c->processor_id & 0xff) {
473 			case PRID_REV_TX3912:
474 				c->cputype = CPU_TX3912;
475 				__cpu_name[cpu] = "TX3912";
476 				c->tlbsize = 32;
477 				break;
478 			case PRID_REV_TX3922:
479 				c->cputype = CPU_TX3922;
480 				__cpu_name[cpu] = "TX3922";
481 				c->tlbsize = 64;
482 				break;
483 			}
484 		}
485 		break;
486 	case PRID_IMP_R4700:
487 		c->cputype = CPU_R4700;
488 		__cpu_name[cpu] = "R4700";
489 		c->isa_level = MIPS_CPU_ISA_III;
490 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
491 		             MIPS_CPU_LLSC;
492 		c->tlbsize = 48;
493 		break;
494 	case PRID_IMP_TX49:
495 		c->cputype = CPU_TX49XX;
496 		__cpu_name[cpu] = "R49XX";
497 		c->isa_level = MIPS_CPU_ISA_III;
498 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
499 		if (!(c->processor_id & 0x08))
500 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
501 		c->tlbsize = 48;
502 		break;
503 	case PRID_IMP_R5000:
504 		c->cputype = CPU_R5000;
505 		__cpu_name[cpu] = "R5000";
506 		c->isa_level = MIPS_CPU_ISA_IV;
507 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
508 		             MIPS_CPU_LLSC;
509 		c->tlbsize = 48;
510 		break;
511 	case PRID_IMP_R5432:
512 		c->cputype = CPU_R5432;
513 		__cpu_name[cpu] = "R5432";
514 		c->isa_level = MIPS_CPU_ISA_IV;
515 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
516 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
517 		c->tlbsize = 48;
518 		break;
519 	case PRID_IMP_R5500:
520 		c->cputype = CPU_R5500;
521 		__cpu_name[cpu] = "R5500";
522 		c->isa_level = MIPS_CPU_ISA_IV;
523 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
524 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
525 		c->tlbsize = 48;
526 		break;
527 	case PRID_IMP_NEVADA:
528 		c->cputype = CPU_NEVADA;
529 		__cpu_name[cpu] = "Nevada";
530 		c->isa_level = MIPS_CPU_ISA_IV;
531 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
532 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
533 		c->tlbsize = 48;
534 		break;
535 	case PRID_IMP_R6000:
536 		c->cputype = CPU_R6000;
537 		__cpu_name[cpu] = "R6000";
538 		c->isa_level = MIPS_CPU_ISA_II;
539 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
540 		             MIPS_CPU_LLSC;
541 		c->tlbsize = 32;
542 		break;
543 	case PRID_IMP_R6000A:
544 		c->cputype = CPU_R6000A;
545 		__cpu_name[cpu] = "R6000A";
546 		c->isa_level = MIPS_CPU_ISA_II;
547 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
548 		             MIPS_CPU_LLSC;
549 		c->tlbsize = 32;
550 		break;
551 	case PRID_IMP_RM7000:
552 		c->cputype = CPU_RM7000;
553 		__cpu_name[cpu] = "RM7000";
554 		c->isa_level = MIPS_CPU_ISA_IV;
555 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
556 		             MIPS_CPU_LLSC;
557 		/*
558 		 * Undocumented RM7000:  Bit 29 in the info register of
559 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
560 		 * entries.
561 		 *
562 		 * 29      1 =>    64 entry JTLB
563 		 *         0 =>    48 entry JTLB
564 		 */
565 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
566 		break;
567 	case PRID_IMP_RM9000:
568 		c->cputype = CPU_RM9000;
569 		__cpu_name[cpu] = "RM9000";
570 		c->isa_level = MIPS_CPU_ISA_IV;
571 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
572 		             MIPS_CPU_LLSC;
573 		/*
574 		 * Bit 29 in the info register of the RM9000
575 		 * indicates if the TLB has 48 or 64 entries.
576 		 *
577 		 * 29      1 =>    64 entry JTLB
578 		 *         0 =>    48 entry JTLB
579 		 */
580 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
581 		break;
582 	case PRID_IMP_R8000:
583 		c->cputype = CPU_R8000;
584 		__cpu_name[cpu] = "RM8000";
585 		c->isa_level = MIPS_CPU_ISA_IV;
586 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
587 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
588 		             MIPS_CPU_LLSC;
589 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
590 		break;
591 	case PRID_IMP_R10000:
592 		c->cputype = CPU_R10000;
593 		__cpu_name[cpu] = "R10000";
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_R12000:
602 		c->cputype = CPU_R12000;
603 		__cpu_name[cpu] = "R12000";
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_R14000:
612 		c->cputype = CPU_R14000;
613 		__cpu_name[cpu] = "R14000";
614 		c->isa_level = MIPS_CPU_ISA_IV;
615 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
616 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
617 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
618 		             MIPS_CPU_LLSC;
619 		c->tlbsize = 64;
620 		break;
621 	case PRID_IMP_LOONGSON2:
622 		c->cputype = CPU_LOONGSON2;
623 		__cpu_name[cpu] = "ICT Loongson-2";
624 
625 		switch (c->processor_id & PRID_REV_MASK) {
626 		case PRID_REV_LOONGSON2E:
627 			set_elf_platform(cpu, "loongson2e");
628 			break;
629 		case PRID_REV_LOONGSON2F:
630 			set_elf_platform(cpu, "loongson2f");
631 			break;
632 		}
633 
634 		c->isa_level = MIPS_CPU_ISA_III;
635 		c->options = R4K_OPTS |
636 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
637 			     MIPS_CPU_32FPR;
638 		c->tlbsize = 64;
639 		break;
640 	}
641 }
642 
643 static char unknown_isa[] __cpuinitdata = KERN_ERR \
644 	"Unsupported ISA type, c0.config0: %d.";
645 
646 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
647 {
648 	unsigned int config0;
649 	int isa;
650 
651 	config0 = read_c0_config();
652 
653 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
654 		c->options |= MIPS_CPU_TLB;
655 	isa = (config0 & MIPS_CONF_AT) >> 13;
656 	switch (isa) {
657 	case 0:
658 		switch ((config0 & MIPS_CONF_AR) >> 10) {
659 		case 0:
660 			c->isa_level = MIPS_CPU_ISA_M32R1;
661 			break;
662 		case 1:
663 			c->isa_level = MIPS_CPU_ISA_M32R2;
664 			break;
665 		default:
666 			goto unknown;
667 		}
668 		break;
669 	case 2:
670 		switch ((config0 & MIPS_CONF_AR) >> 10) {
671 		case 0:
672 			c->isa_level = MIPS_CPU_ISA_M64R1;
673 			break;
674 		case 1:
675 			c->isa_level = MIPS_CPU_ISA_M64R2;
676 			break;
677 		default:
678 			goto unknown;
679 		}
680 		break;
681 	default:
682 		goto unknown;
683 	}
684 
685 	return config0 & MIPS_CONF_M;
686 
687 unknown:
688 	panic(unknown_isa, config0);
689 }
690 
691 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
692 {
693 	unsigned int config1;
694 
695 	config1 = read_c0_config1();
696 
697 	if (config1 & MIPS_CONF1_MD)
698 		c->ases |= MIPS_ASE_MDMX;
699 	if (config1 & MIPS_CONF1_WR)
700 		c->options |= MIPS_CPU_WATCH;
701 	if (config1 & MIPS_CONF1_CA)
702 		c->ases |= MIPS_ASE_MIPS16;
703 	if (config1 & MIPS_CONF1_EP)
704 		c->options |= MIPS_CPU_EJTAG;
705 	if (config1 & MIPS_CONF1_FP) {
706 		c->options |= MIPS_CPU_FPU;
707 		c->options |= MIPS_CPU_32FPR;
708 	}
709 	if (cpu_has_tlb)
710 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
711 
712 	return config1 & MIPS_CONF_M;
713 }
714 
715 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
716 {
717 	unsigned int config2;
718 
719 	config2 = read_c0_config2();
720 
721 	if (config2 & MIPS_CONF2_SL)
722 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
723 
724 	return config2 & MIPS_CONF_M;
725 }
726 
727 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
728 {
729 	unsigned int config3;
730 
731 	config3 = read_c0_config3();
732 
733 	if (config3 & MIPS_CONF3_SM)
734 		c->ases |= MIPS_ASE_SMARTMIPS;
735 	if (config3 & MIPS_CONF3_DSP)
736 		c->ases |= MIPS_ASE_DSP;
737 	if (config3 & MIPS_CONF3_VINT)
738 		c->options |= MIPS_CPU_VINT;
739 	if (config3 & MIPS_CONF3_VEIC)
740 		c->options |= MIPS_CPU_VEIC;
741 	if (config3 & MIPS_CONF3_MT)
742 	        c->ases |= MIPS_ASE_MIPSMT;
743 	if (config3 & MIPS_CONF3_ULRI)
744 		c->options |= MIPS_CPU_ULRI;
745 
746 	return config3 & MIPS_CONF_M;
747 }
748 
749 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
750 {
751 	unsigned int config4;
752 
753 	config4 = read_c0_config4();
754 
755 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
756 	    && cpu_has_tlb)
757 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
758 
759 	c->kscratch_mask = (config4 >> 16) & 0xff;
760 
761 	return config4 & MIPS_CONF_M;
762 }
763 
764 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
765 {
766 	int ok;
767 
768 	/* MIPS32 or MIPS64 compliant CPU.  */
769 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
770 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
771 
772 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
773 
774 	ok = decode_config0(c);			/* Read Config registers.  */
775 	BUG_ON(!ok);				/* Arch spec violation!  */
776 	if (ok)
777 		ok = decode_config1(c);
778 	if (ok)
779 		ok = decode_config2(c);
780 	if (ok)
781 		ok = decode_config3(c);
782 	if (ok)
783 		ok = decode_config4(c);
784 
785 	mips_probe_watch_registers(c);
786 
787 	if (cpu_has_mips_r2)
788 		c->core = read_c0_ebase() & 0x3ff;
789 }
790 
791 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
792 {
793 	decode_configs(c);
794 	switch (c->processor_id & 0xff00) {
795 	case PRID_IMP_4KC:
796 		c->cputype = CPU_4KC;
797 		__cpu_name[cpu] = "MIPS 4Kc";
798 		break;
799 	case PRID_IMP_4KEC:
800 	case PRID_IMP_4KECR2:
801 		c->cputype = CPU_4KEC;
802 		__cpu_name[cpu] = "MIPS 4KEc";
803 		break;
804 	case PRID_IMP_4KSC:
805 	case PRID_IMP_4KSD:
806 		c->cputype = CPU_4KSC;
807 		__cpu_name[cpu] = "MIPS 4KSc";
808 		break;
809 	case PRID_IMP_5KC:
810 		c->cputype = CPU_5KC;
811 		__cpu_name[cpu] = "MIPS 5Kc";
812 		break;
813 	case PRID_IMP_20KC:
814 		c->cputype = CPU_20KC;
815 		__cpu_name[cpu] = "MIPS 20Kc";
816 		break;
817 	case PRID_IMP_24K:
818 	case PRID_IMP_24KE:
819 		c->cputype = CPU_24K;
820 		__cpu_name[cpu] = "MIPS 24Kc";
821 		break;
822 	case PRID_IMP_25KF:
823 		c->cputype = CPU_25KF;
824 		__cpu_name[cpu] = "MIPS 25Kc";
825 		break;
826 	case PRID_IMP_34K:
827 		c->cputype = CPU_34K;
828 		__cpu_name[cpu] = "MIPS 34Kc";
829 		break;
830 	case PRID_IMP_74K:
831 		c->cputype = CPU_74K;
832 		__cpu_name[cpu] = "MIPS 74Kc";
833 		break;
834 	case PRID_IMP_1004K:
835 		c->cputype = CPU_1004K;
836 		__cpu_name[cpu] = "MIPS 1004Kc";
837 		break;
838 	}
839 
840 	spram_config();
841 }
842 
843 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
844 {
845 	decode_configs(c);
846 	switch (c->processor_id & 0xff00) {
847 	case PRID_IMP_AU1_REV1:
848 	case PRID_IMP_AU1_REV2:
849 		c->cputype = CPU_ALCHEMY;
850 		switch ((c->processor_id >> 24) & 0xff) {
851 		case 0:
852 			__cpu_name[cpu] = "Au1000";
853 			break;
854 		case 1:
855 			__cpu_name[cpu] = "Au1500";
856 			break;
857 		case 2:
858 			__cpu_name[cpu] = "Au1100";
859 			break;
860 		case 3:
861 			__cpu_name[cpu] = "Au1550";
862 			break;
863 		case 4:
864 			__cpu_name[cpu] = "Au1200";
865 			if ((c->processor_id & 0xff) == 2)
866 				__cpu_name[cpu] = "Au1250";
867 			break;
868 		case 5:
869 			__cpu_name[cpu] = "Au1210";
870 			break;
871 		default:
872 			__cpu_name[cpu] = "Au1xxx";
873 			break;
874 		}
875 		break;
876 	}
877 }
878 
879 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
880 {
881 	decode_configs(c);
882 
883 	switch (c->processor_id & 0xff00) {
884 	case PRID_IMP_SB1:
885 		c->cputype = CPU_SB1;
886 		__cpu_name[cpu] = "SiByte SB1";
887 		/* FPU in pass1 is known to have issues. */
888 		if ((c->processor_id & 0xff) < 0x02)
889 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
890 		break;
891 	case PRID_IMP_SB1A:
892 		c->cputype = CPU_SB1A;
893 		__cpu_name[cpu] = "SiByte SB1A";
894 		break;
895 	}
896 }
897 
898 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
899 {
900 	decode_configs(c);
901 	switch (c->processor_id & 0xff00) {
902 	case PRID_IMP_SR71000:
903 		c->cputype = CPU_SR71000;
904 		__cpu_name[cpu] = "Sandcraft SR71000";
905 		c->scache.ways = 8;
906 		c->tlbsize = 64;
907 		break;
908 	}
909 }
910 
911 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
912 {
913 	decode_configs(c);
914 	switch (c->processor_id & 0xff00) {
915 	case PRID_IMP_PR4450:
916 		c->cputype = CPU_PR4450;
917 		__cpu_name[cpu] = "Philips PR4450";
918 		c->isa_level = MIPS_CPU_ISA_M32R1;
919 		break;
920 	}
921 }
922 
923 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
924 {
925 	decode_configs(c);
926 	switch (c->processor_id & 0xff00) {
927 	case PRID_IMP_BMIPS32_REV4:
928 	case PRID_IMP_BMIPS32_REV8:
929 		c->cputype = CPU_BMIPS32;
930 		__cpu_name[cpu] = "Broadcom BMIPS32";
931 		set_elf_platform(cpu, "bmips32");
932 		break;
933 	case PRID_IMP_BMIPS3300:
934 	case PRID_IMP_BMIPS3300_ALT:
935 	case PRID_IMP_BMIPS3300_BUG:
936 		c->cputype = CPU_BMIPS3300;
937 		__cpu_name[cpu] = "Broadcom BMIPS3300";
938 		set_elf_platform(cpu, "bmips3300");
939 		break;
940 	case PRID_IMP_BMIPS43XX: {
941 		int rev = c->processor_id & 0xff;
942 
943 		if (rev >= PRID_REV_BMIPS4380_LO &&
944 				rev <= PRID_REV_BMIPS4380_HI) {
945 			c->cputype = CPU_BMIPS4380;
946 			__cpu_name[cpu] = "Broadcom BMIPS4380";
947 			set_elf_platform(cpu, "bmips4380");
948 		} else {
949 			c->cputype = CPU_BMIPS4350;
950 			__cpu_name[cpu] = "Broadcom BMIPS4350";
951 			set_elf_platform(cpu, "bmips4350");
952 		}
953 		break;
954 	}
955 	case PRID_IMP_BMIPS5000:
956 		c->cputype = CPU_BMIPS5000;
957 		__cpu_name[cpu] = "Broadcom BMIPS5000";
958 		set_elf_platform(cpu, "bmips5000");
959 		c->options |= MIPS_CPU_ULRI;
960 		break;
961 	}
962 }
963 
964 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
965 {
966 	decode_configs(c);
967 	switch (c->processor_id & 0xff00) {
968 	case PRID_IMP_CAVIUM_CN38XX:
969 	case PRID_IMP_CAVIUM_CN31XX:
970 	case PRID_IMP_CAVIUM_CN30XX:
971 		c->cputype = CPU_CAVIUM_OCTEON;
972 		__cpu_name[cpu] = "Cavium Octeon";
973 		goto platform;
974 	case PRID_IMP_CAVIUM_CN58XX:
975 	case PRID_IMP_CAVIUM_CN56XX:
976 	case PRID_IMP_CAVIUM_CN50XX:
977 	case PRID_IMP_CAVIUM_CN52XX:
978 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
979 		__cpu_name[cpu] = "Cavium Octeon+";
980 platform:
981 		set_elf_platform(cpu, "octeon");
982 		break;
983 	case PRID_IMP_CAVIUM_CN61XX:
984 	case PRID_IMP_CAVIUM_CN63XX:
985 	case PRID_IMP_CAVIUM_CN66XX:
986 	case PRID_IMP_CAVIUM_CN68XX:
987 		c->cputype = CPU_CAVIUM_OCTEON2;
988 		__cpu_name[cpu] = "Cavium Octeon II";
989 		set_elf_platform(cpu, "octeon2");
990 		break;
991 	default:
992 		printk(KERN_INFO "Unknown Octeon chip!\n");
993 		c->cputype = CPU_UNKNOWN;
994 		break;
995 	}
996 }
997 
998 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
999 {
1000 	decode_configs(c);
1001 	/* JZRISC does not implement the CP0 counter. */
1002 	c->options &= ~MIPS_CPU_COUNTER;
1003 	switch (c->processor_id & 0xff00) {
1004 	case PRID_IMP_JZRISC:
1005 		c->cputype = CPU_JZRISC;
1006 		__cpu_name[cpu] = "Ingenic JZRISC";
1007 		break;
1008 	default:
1009 		panic("Unknown Ingenic Processor ID!");
1010 		break;
1011 	}
1012 }
1013 
1014 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1015 {
1016 	decode_configs(c);
1017 
1018 	if ((c->processor_id & 0xff00) == PRID_IMP_NETLOGIC_AU13XX) {
1019 		c->cputype = CPU_ALCHEMY;
1020 		__cpu_name[cpu] = "Au1300";
1021 		/* following stuff is not for Alchemy */
1022 		return;
1023 	}
1024 
1025 	c->options = (MIPS_CPU_TLB       |
1026 			MIPS_CPU_4KEX    |
1027 			MIPS_CPU_COUNTER |
1028 			MIPS_CPU_DIVEC   |
1029 			MIPS_CPU_WATCH   |
1030 			MIPS_CPU_EJTAG   |
1031 			MIPS_CPU_LLSC);
1032 
1033 	switch (c->processor_id & 0xff00) {
1034 	case PRID_IMP_NETLOGIC_XLP8XX:
1035 	case PRID_IMP_NETLOGIC_XLP3XX:
1036 		c->cputype = CPU_XLP;
1037 		__cpu_name[cpu] = "Netlogic XLP";
1038 		break;
1039 
1040 	case PRID_IMP_NETLOGIC_XLR732:
1041 	case PRID_IMP_NETLOGIC_XLR716:
1042 	case PRID_IMP_NETLOGIC_XLR532:
1043 	case PRID_IMP_NETLOGIC_XLR308:
1044 	case PRID_IMP_NETLOGIC_XLR532C:
1045 	case PRID_IMP_NETLOGIC_XLR516C:
1046 	case PRID_IMP_NETLOGIC_XLR508C:
1047 	case PRID_IMP_NETLOGIC_XLR308C:
1048 		c->cputype = CPU_XLR;
1049 		__cpu_name[cpu] = "Netlogic XLR";
1050 		break;
1051 
1052 	case PRID_IMP_NETLOGIC_XLS608:
1053 	case PRID_IMP_NETLOGIC_XLS408:
1054 	case PRID_IMP_NETLOGIC_XLS404:
1055 	case PRID_IMP_NETLOGIC_XLS208:
1056 	case PRID_IMP_NETLOGIC_XLS204:
1057 	case PRID_IMP_NETLOGIC_XLS108:
1058 	case PRID_IMP_NETLOGIC_XLS104:
1059 	case PRID_IMP_NETLOGIC_XLS616B:
1060 	case PRID_IMP_NETLOGIC_XLS608B:
1061 	case PRID_IMP_NETLOGIC_XLS416B:
1062 	case PRID_IMP_NETLOGIC_XLS412B:
1063 	case PRID_IMP_NETLOGIC_XLS408B:
1064 	case PRID_IMP_NETLOGIC_XLS404B:
1065 		c->cputype = CPU_XLR;
1066 		__cpu_name[cpu] = "Netlogic XLS";
1067 		break;
1068 
1069 	default:
1070 		pr_info("Unknown Netlogic chip id [%02x]!\n",
1071 		       c->processor_id);
1072 		c->cputype = CPU_XLR;
1073 		break;
1074 	}
1075 
1076 	if (c->cputype == CPU_XLP) {
1077 		c->isa_level = MIPS_CPU_ISA_M64R2;
1078 		c->options |= (MIPS_CPU_FPU | MIPS_CPU_ULRI | MIPS_CPU_MCHECK);
1079 		/* This will be updated again after all threads are woken up */
1080 		c->tlbsize = ((read_c0_config6() >> 16) & 0xffff) + 1;
1081 	} else {
1082 		c->isa_level = MIPS_CPU_ISA_M64R1;
1083 		c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
1084 	}
1085 }
1086 
1087 #ifdef CONFIG_64BIT
1088 /* For use by uaccess.h */
1089 u64 __ua_limit;
1090 EXPORT_SYMBOL(__ua_limit);
1091 #endif
1092 
1093 const char *__cpu_name[NR_CPUS];
1094 const char *__elf_platform;
1095 
1096 __cpuinit void cpu_probe(void)
1097 {
1098 	struct cpuinfo_mips *c = &current_cpu_data;
1099 	unsigned int cpu = smp_processor_id();
1100 
1101 	c->processor_id	= PRID_IMP_UNKNOWN;
1102 	c->fpu_id	= FPIR_IMP_NONE;
1103 	c->cputype	= CPU_UNKNOWN;
1104 
1105 	c->processor_id = read_c0_prid();
1106 	switch (c->processor_id & 0xff0000) {
1107 	case PRID_COMP_LEGACY:
1108 		cpu_probe_legacy(c, cpu);
1109 		break;
1110 	case PRID_COMP_MIPS:
1111 		cpu_probe_mips(c, cpu);
1112 		break;
1113 	case PRID_COMP_ALCHEMY:
1114 		cpu_probe_alchemy(c, cpu);
1115 		break;
1116 	case PRID_COMP_SIBYTE:
1117 		cpu_probe_sibyte(c, cpu);
1118 		break;
1119 	case PRID_COMP_BROADCOM:
1120 		cpu_probe_broadcom(c, cpu);
1121 		break;
1122 	case PRID_COMP_SANDCRAFT:
1123 		cpu_probe_sandcraft(c, cpu);
1124 		break;
1125 	case PRID_COMP_NXP:
1126 		cpu_probe_nxp(c, cpu);
1127 		break;
1128 	case PRID_COMP_CAVIUM:
1129 		cpu_probe_cavium(c, cpu);
1130 		break;
1131 	case PRID_COMP_INGENIC:
1132 		cpu_probe_ingenic(c, cpu);
1133 		break;
1134 	case PRID_COMP_NETLOGIC:
1135 		cpu_probe_netlogic(c, cpu);
1136 		break;
1137 	}
1138 
1139 	BUG_ON(!__cpu_name[cpu]);
1140 	BUG_ON(c->cputype == CPU_UNKNOWN);
1141 
1142 	/*
1143 	 * Platform code can force the cpu type to optimize code
1144 	 * generation. In that case be sure the cpu type is correctly
1145 	 * manually setup otherwise it could trigger some nasty bugs.
1146 	 */
1147 	BUG_ON(current_cpu_type() != c->cputype);
1148 
1149 	if (mips_fpu_disabled)
1150 		c->options &= ~MIPS_CPU_FPU;
1151 
1152 	if (mips_dsp_disabled)
1153 		c->ases &= ~MIPS_ASE_DSP;
1154 
1155 	if (c->options & MIPS_CPU_FPU) {
1156 		c->fpu_id = cpu_get_fpu_id();
1157 
1158 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1159 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1160 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1161 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1162 			if (c->fpu_id & MIPS_FPIR_3D)
1163 				c->ases |= MIPS_ASE_MIPS3D;
1164 		}
1165 	}
1166 
1167 	if (cpu_has_mips_r2)
1168 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1169 	else
1170 		c->srsets = 1;
1171 
1172 	cpu_probe_vmbits(c);
1173 
1174 #ifdef CONFIG_64BIT
1175 	if (cpu == 0)
1176 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
1177 #endif
1178 }
1179 
1180 __cpuinit void cpu_report(void)
1181 {
1182 	struct cpuinfo_mips *c = &current_cpu_data;
1183 
1184 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1185 	       c->processor_id, cpu_name_string());
1186 	if (c->options & MIPS_CPU_FPU)
1187 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1188 }
1189