xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision 615c36f5)
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/system.h>
26 #include <asm/watch.h>
27 #include <asm/elf.h>
28 #include <asm/spram.h>
29 #include <asm/uaccess.h>
30 
31 /*
32  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
33  * the implementation of the "wait" feature differs between CPU families. This
34  * points to the function that implements CPU specific wait.
35  * The wait instruction stops the pipeline and reduces the power consumption of
36  * the CPU very much.
37  */
38 void (*cpu_wait)(void);
39 EXPORT_SYMBOL(cpu_wait);
40 
41 static void r3081_wait(void)
42 {
43 	unsigned long cfg = read_c0_conf();
44 	write_c0_conf(cfg | R30XX_CONF_HALT);
45 }
46 
47 static void r39xx_wait(void)
48 {
49 	local_irq_disable();
50 	if (!need_resched())
51 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
52 	local_irq_enable();
53 }
54 
55 extern void r4k_wait(void);
56 
57 /*
58  * This variant is preferable as it allows testing need_resched and going to
59  * sleep depending on the outcome atomically.  Unfortunately the "It is
60  * implementation-dependent whether the pipeline restarts when a non-enabled
61  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
62  * using this version a gamble.
63  */
64 void r4k_wait_irqoff(void)
65 {
66 	local_irq_disable();
67 	if (!need_resched())
68 		__asm__("	.set	push		\n"
69 			"	.set	mips3		\n"
70 			"	wait			\n"
71 			"	.set	pop		\n");
72 	local_irq_enable();
73 	__asm__(" 	.globl __pastwait	\n"
74 		"__pastwait:			\n");
75 }
76 
77 /*
78  * The RM7000 variant has to handle erratum 38.  The workaround is to not
79  * have any pending stores when the WAIT instruction is executed.
80  */
81 static void rm7k_wait_irqoff(void)
82 {
83 	local_irq_disable();
84 	if (!need_resched())
85 		__asm__(
86 		"	.set	push					\n"
87 		"	.set	mips3					\n"
88 		"	.set	noat					\n"
89 		"	mfc0	$1, $12					\n"
90 		"	sync						\n"
91 		"	mtc0	$1, $12		# stalls until W stage	\n"
92 		"	wait						\n"
93 		"	mtc0	$1, $12		# stalls until W stage	\n"
94 		"	.set	pop					\n");
95 	local_irq_enable();
96 }
97 
98 /*
99  * The Au1xxx wait is available only if using 32khz counter or
100  * external timer source, but specifically not CP0 Counter.
101  * alchemy/common/time.c may override cpu_wait!
102  */
103 static void au1k_wait(void)
104 {
105 	__asm__("	.set	mips3			\n"
106 		"	cache	0x14, 0(%0)		\n"
107 		"	cache	0x14, 32(%0)		\n"
108 		"	sync				\n"
109 		"	nop				\n"
110 		"	wait				\n"
111 		"	nop				\n"
112 		"	nop				\n"
113 		"	nop				\n"
114 		"	nop				\n"
115 		"	.set	mips0			\n"
116 		: : "r" (au1k_wait));
117 }
118 
119 static int __initdata nowait;
120 
121 static int __init wait_disable(char *s)
122 {
123 	nowait = 1;
124 
125 	return 1;
126 }
127 
128 __setup("nowait", wait_disable);
129 
130 static int __cpuinitdata mips_fpu_disabled;
131 
132 static int __init fpu_disable(char *s)
133 {
134 	cpu_data[0].options &= ~MIPS_CPU_FPU;
135 	mips_fpu_disabled = 1;
136 
137 	return 1;
138 }
139 
140 __setup("nofpu", fpu_disable);
141 
142 int __cpuinitdata mips_dsp_disabled;
143 
144 static int __init dsp_disable(char *s)
145 {
146 	cpu_data[0].ases &= ~MIPS_ASE_DSP;
147 	mips_dsp_disabled = 1;
148 
149 	return 1;
150 }
151 
152 __setup("nodsp", dsp_disable);
153 
154 void __init check_wait(void)
155 {
156 	struct cpuinfo_mips *c = &current_cpu_data;
157 
158 	if (nowait) {
159 		printk("Wait instruction disabled.\n");
160 		return;
161 	}
162 
163 	switch (c->cputype) {
164 	case CPU_R3081:
165 	case CPU_R3081E:
166 		cpu_wait = r3081_wait;
167 		break;
168 	case CPU_TX3927:
169 		cpu_wait = r39xx_wait;
170 		break;
171 	case CPU_R4200:
172 /*	case CPU_R4300: */
173 	case CPU_R4600:
174 	case CPU_R4640:
175 	case CPU_R4650:
176 	case CPU_R4700:
177 	case CPU_R5000:
178 	case CPU_R5500:
179 	case CPU_NEVADA:
180 	case CPU_4KC:
181 	case CPU_4KEC:
182 	case CPU_4KSC:
183 	case CPU_5KC:
184 	case CPU_25KF:
185 	case CPU_PR4450:
186 	case CPU_BMIPS3300:
187 	case CPU_BMIPS4350:
188 	case CPU_BMIPS4380:
189 	case CPU_BMIPS5000:
190 	case CPU_CAVIUM_OCTEON:
191 	case CPU_CAVIUM_OCTEON_PLUS:
192 	case CPU_CAVIUM_OCTEON2:
193 	case CPU_JZRISC:
194 		cpu_wait = r4k_wait;
195 		break;
196 
197 	case CPU_RM7000:
198 		cpu_wait = rm7k_wait_irqoff;
199 		break;
200 
201 	case CPU_24K:
202 	case CPU_34K:
203 	case CPU_1004K:
204 		cpu_wait = r4k_wait;
205 		if (read_c0_config7() & MIPS_CONF7_WII)
206 			cpu_wait = r4k_wait_irqoff;
207 		break;
208 
209 	case CPU_74K:
210 		cpu_wait = r4k_wait;
211 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
212 			cpu_wait = r4k_wait_irqoff;
213 		break;
214 
215 	case CPU_TX49XX:
216 		cpu_wait = r4k_wait_irqoff;
217 		break;
218 	case CPU_ALCHEMY:
219 		cpu_wait = au1k_wait;
220 		break;
221 	case CPU_20KC:
222 		/*
223 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
224 		 * WAIT on Rev2.0 and Rev3.0 has E16.
225 		 * Rev3.1 WAIT is nop, why bother
226 		 */
227 		if ((c->processor_id & 0xff) <= 0x64)
228 			break;
229 
230 		/*
231 		 * Another rev is incremeting c0_count at a reduced clock
232 		 * rate while in WAIT mode.  So we basically have the choice
233 		 * between using the cp0 timer as clocksource or avoiding
234 		 * the WAIT instruction.  Until more details are known,
235 		 * disable the use of WAIT for 20Kc entirely.
236 		   cpu_wait = r4k_wait;
237 		 */
238 		break;
239 	case CPU_RM9000:
240 		if ((c->processor_id & 0x00ff) >= 0x40)
241 			cpu_wait = r4k_wait;
242 		break;
243 	default:
244 		break;
245 	}
246 }
247 
248 static inline void check_errata(void)
249 {
250 	struct cpuinfo_mips *c = &current_cpu_data;
251 
252 	switch (c->cputype) {
253 	case CPU_34K:
254 		/*
255 		 * Erratum "RPS May Cause Incorrect Instruction Execution"
256 		 * This code only handles VPE0, any SMP/SMTC/RTOS code
257 		 * making use of VPE1 will be responsable for that VPE.
258 		 */
259 		if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
260 			write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
261 		break;
262 	default:
263 		break;
264 	}
265 }
266 
267 void __init check_bugs32(void)
268 {
269 	check_errata();
270 }
271 
272 /*
273  * Probe whether cpu has config register by trying to play with
274  * alternate cache bit and see whether it matters.
275  * It's used by cpu_probe to distinguish between R3000A and R3081.
276  */
277 static inline int cpu_has_confreg(void)
278 {
279 #ifdef CONFIG_CPU_R3000
280 	extern unsigned long r3k_cache_size(unsigned long);
281 	unsigned long size1, size2;
282 	unsigned long cfg = read_c0_conf();
283 
284 	size1 = r3k_cache_size(ST0_ISC);
285 	write_c0_conf(cfg ^ R30XX_CONF_AC);
286 	size2 = r3k_cache_size(ST0_ISC);
287 	write_c0_conf(cfg);
288 	return size1 != size2;
289 #else
290 	return 0;
291 #endif
292 }
293 
294 static inline void set_elf_platform(int cpu, const char *plat)
295 {
296 	if (cpu == 0)
297 		__elf_platform = plat;
298 }
299 
300 /*
301  * Get the FPU Implementation/Revision.
302  */
303 static inline unsigned long cpu_get_fpu_id(void)
304 {
305 	unsigned long tmp, fpu_id;
306 
307 	tmp = read_c0_status();
308 	__enable_fpu();
309 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
310 	write_c0_status(tmp);
311 	return fpu_id;
312 }
313 
314 /*
315  * Check the CPU has an FPU the official way.
316  */
317 static inline int __cpu_has_fpu(void)
318 {
319 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
320 }
321 
322 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
323 {
324 #ifdef __NEED_VMBITS_PROBE
325 	write_c0_entryhi(0x3fffffffffffe000ULL);
326 	back_to_back_c0_hazard();
327 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
328 #endif
329 }
330 
331 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
332 		| MIPS_CPU_COUNTER)
333 
334 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
335 {
336 	switch (c->processor_id & 0xff00) {
337 	case PRID_IMP_R2000:
338 		c->cputype = CPU_R2000;
339 		__cpu_name[cpu] = "R2000";
340 		c->isa_level = MIPS_CPU_ISA_I;
341 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
342 		             MIPS_CPU_NOFPUEX;
343 		if (__cpu_has_fpu())
344 			c->options |= MIPS_CPU_FPU;
345 		c->tlbsize = 64;
346 		break;
347 	case PRID_IMP_R3000:
348 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
349 			if (cpu_has_confreg()) {
350 				c->cputype = CPU_R3081E;
351 				__cpu_name[cpu] = "R3081";
352 			} else {
353 				c->cputype = CPU_R3000A;
354 				__cpu_name[cpu] = "R3000A";
355 			}
356 			break;
357 		} else {
358 			c->cputype = CPU_R3000;
359 			__cpu_name[cpu] = "R3000";
360 		}
361 		c->isa_level = MIPS_CPU_ISA_I;
362 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
363 		             MIPS_CPU_NOFPUEX;
364 		if (__cpu_has_fpu())
365 			c->options |= MIPS_CPU_FPU;
366 		c->tlbsize = 64;
367 		break;
368 	case PRID_IMP_R4000:
369 		if (read_c0_config() & CONF_SC) {
370 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
371 				c->cputype = CPU_R4400PC;
372 				__cpu_name[cpu] = "R4400PC";
373 			} else {
374 				c->cputype = CPU_R4000PC;
375 				__cpu_name[cpu] = "R4000PC";
376 			}
377 		} else {
378 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
379 				c->cputype = CPU_R4400SC;
380 				__cpu_name[cpu] = "R4400SC";
381 			} else {
382 				c->cputype = CPU_R4000SC;
383 				__cpu_name[cpu] = "R4000SC";
384 			}
385 		}
386 
387 		c->isa_level = MIPS_CPU_ISA_III;
388 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
389 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
390 		             MIPS_CPU_LLSC;
391 		c->tlbsize = 48;
392 		break;
393 	case PRID_IMP_VR41XX:
394 		switch (c->processor_id & 0xf0) {
395 		case PRID_REV_VR4111:
396 			c->cputype = CPU_VR4111;
397 			__cpu_name[cpu] = "NEC VR4111";
398 			break;
399 		case PRID_REV_VR4121:
400 			c->cputype = CPU_VR4121;
401 			__cpu_name[cpu] = "NEC VR4121";
402 			break;
403 		case PRID_REV_VR4122:
404 			if ((c->processor_id & 0xf) < 0x3) {
405 				c->cputype = CPU_VR4122;
406 				__cpu_name[cpu] = "NEC VR4122";
407 			} else {
408 				c->cputype = CPU_VR4181A;
409 				__cpu_name[cpu] = "NEC VR4181A";
410 			}
411 			break;
412 		case PRID_REV_VR4130:
413 			if ((c->processor_id & 0xf) < 0x4) {
414 				c->cputype = CPU_VR4131;
415 				__cpu_name[cpu] = "NEC VR4131";
416 			} else {
417 				c->cputype = CPU_VR4133;
418 				__cpu_name[cpu] = "NEC VR4133";
419 			}
420 			break;
421 		default:
422 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
423 			c->cputype = CPU_VR41XX;
424 			__cpu_name[cpu] = "NEC Vr41xx";
425 			break;
426 		}
427 		c->isa_level = MIPS_CPU_ISA_III;
428 		c->options = R4K_OPTS;
429 		c->tlbsize = 32;
430 		break;
431 	case PRID_IMP_R4300:
432 		c->cputype = CPU_R4300;
433 		__cpu_name[cpu] = "R4300";
434 		c->isa_level = MIPS_CPU_ISA_III;
435 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
436 		             MIPS_CPU_LLSC;
437 		c->tlbsize = 32;
438 		break;
439 	case PRID_IMP_R4600:
440 		c->cputype = CPU_R4600;
441 		__cpu_name[cpu] = "R4600";
442 		c->isa_level = MIPS_CPU_ISA_III;
443 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
444 			     MIPS_CPU_LLSC;
445 		c->tlbsize = 48;
446 		break;
447 	#if 0
448  	case PRID_IMP_R4650:
449 		/*
450 		 * This processor doesn't have an MMU, so it's not
451 		 * "real easy" to run Linux on it. It is left purely
452 		 * for documentation.  Commented out because it shares
453 		 * it's c0_prid id number with the TX3900.
454 		 */
455 		c->cputype = CPU_R4650;
456 		__cpu_name[cpu] = "R4650";
457 	 	c->isa_level = MIPS_CPU_ISA_III;
458 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
459 	        c->tlbsize = 48;
460 		break;
461 	#endif
462 	case PRID_IMP_TX39:
463 		c->isa_level = MIPS_CPU_ISA_I;
464 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
465 
466 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
467 			c->cputype = CPU_TX3927;
468 			__cpu_name[cpu] = "TX3927";
469 			c->tlbsize = 64;
470 		} else {
471 			switch (c->processor_id & 0xff) {
472 			case PRID_REV_TX3912:
473 				c->cputype = CPU_TX3912;
474 				__cpu_name[cpu] = "TX3912";
475 				c->tlbsize = 32;
476 				break;
477 			case PRID_REV_TX3922:
478 				c->cputype = CPU_TX3922;
479 				__cpu_name[cpu] = "TX3922";
480 				c->tlbsize = 64;
481 				break;
482 			}
483 		}
484 		break;
485 	case PRID_IMP_R4700:
486 		c->cputype = CPU_R4700;
487 		__cpu_name[cpu] = "R4700";
488 		c->isa_level = MIPS_CPU_ISA_III;
489 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
490 		             MIPS_CPU_LLSC;
491 		c->tlbsize = 48;
492 		break;
493 	case PRID_IMP_TX49:
494 		c->cputype = CPU_TX49XX;
495 		__cpu_name[cpu] = "R49XX";
496 		c->isa_level = MIPS_CPU_ISA_III;
497 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
498 		if (!(c->processor_id & 0x08))
499 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
500 		c->tlbsize = 48;
501 		break;
502 	case PRID_IMP_R5000:
503 		c->cputype = CPU_R5000;
504 		__cpu_name[cpu] = "R5000";
505 		c->isa_level = MIPS_CPU_ISA_IV;
506 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
507 		             MIPS_CPU_LLSC;
508 		c->tlbsize = 48;
509 		break;
510 	case PRID_IMP_R5432:
511 		c->cputype = CPU_R5432;
512 		__cpu_name[cpu] = "R5432";
513 		c->isa_level = MIPS_CPU_ISA_IV;
514 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
515 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
516 		c->tlbsize = 48;
517 		break;
518 	case PRID_IMP_R5500:
519 		c->cputype = CPU_R5500;
520 		__cpu_name[cpu] = "R5500";
521 		c->isa_level = MIPS_CPU_ISA_IV;
522 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
523 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
524 		c->tlbsize = 48;
525 		break;
526 	case PRID_IMP_NEVADA:
527 		c->cputype = CPU_NEVADA;
528 		__cpu_name[cpu] = "Nevada";
529 		c->isa_level = MIPS_CPU_ISA_IV;
530 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
531 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
532 		c->tlbsize = 48;
533 		break;
534 	case PRID_IMP_R6000:
535 		c->cputype = CPU_R6000;
536 		__cpu_name[cpu] = "R6000";
537 		c->isa_level = MIPS_CPU_ISA_II;
538 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
539 		             MIPS_CPU_LLSC;
540 		c->tlbsize = 32;
541 		break;
542 	case PRID_IMP_R6000A:
543 		c->cputype = CPU_R6000A;
544 		__cpu_name[cpu] = "R6000A";
545 		c->isa_level = MIPS_CPU_ISA_II;
546 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
547 		             MIPS_CPU_LLSC;
548 		c->tlbsize = 32;
549 		break;
550 	case PRID_IMP_RM7000:
551 		c->cputype = CPU_RM7000;
552 		__cpu_name[cpu] = "RM7000";
553 		c->isa_level = MIPS_CPU_ISA_IV;
554 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
555 		             MIPS_CPU_LLSC;
556 		/*
557 		 * Undocumented RM7000:  Bit 29 in the info register of
558 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
559 		 * entries.
560 		 *
561 		 * 29      1 =>    64 entry JTLB
562 		 *         0 =>    48 entry JTLB
563 		 */
564 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
565 		break;
566 	case PRID_IMP_RM9000:
567 		c->cputype = CPU_RM9000;
568 		__cpu_name[cpu] = "RM9000";
569 		c->isa_level = MIPS_CPU_ISA_IV;
570 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
571 		             MIPS_CPU_LLSC;
572 		/*
573 		 * Bit 29 in the info register of the RM9000
574 		 * indicates if the TLB has 48 or 64 entries.
575 		 *
576 		 * 29      1 =>    64 entry JTLB
577 		 *         0 =>    48 entry JTLB
578 		 */
579 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
580 		break;
581 	case PRID_IMP_R8000:
582 		c->cputype = CPU_R8000;
583 		__cpu_name[cpu] = "RM8000";
584 		c->isa_level = MIPS_CPU_ISA_IV;
585 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
586 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
587 		             MIPS_CPU_LLSC;
588 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
589 		break;
590 	case PRID_IMP_R10000:
591 		c->cputype = CPU_R10000;
592 		__cpu_name[cpu] = "R10000";
593 		c->isa_level = MIPS_CPU_ISA_IV;
594 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
595 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
596 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
597 		             MIPS_CPU_LLSC;
598 		c->tlbsize = 64;
599 		break;
600 	case PRID_IMP_R12000:
601 		c->cputype = CPU_R12000;
602 		__cpu_name[cpu] = "R12000";
603 		c->isa_level = MIPS_CPU_ISA_IV;
604 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
605 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
606 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
607 		             MIPS_CPU_LLSC;
608 		c->tlbsize = 64;
609 		break;
610 	case PRID_IMP_R14000:
611 		c->cputype = CPU_R14000;
612 		__cpu_name[cpu] = "R14000";
613 		c->isa_level = MIPS_CPU_ISA_IV;
614 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
615 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
616 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
617 		             MIPS_CPU_LLSC;
618 		c->tlbsize = 64;
619 		break;
620 	case PRID_IMP_LOONGSON2:
621 		c->cputype = CPU_LOONGSON2;
622 		__cpu_name[cpu] = "ICT Loongson-2";
623 
624 		switch (c->processor_id & PRID_REV_MASK) {
625 		case PRID_REV_LOONGSON2E:
626 			set_elf_platform(cpu, "loongson2e");
627 			break;
628 		case PRID_REV_LOONGSON2F:
629 			set_elf_platform(cpu, "loongson2f");
630 			break;
631 		}
632 
633 		c->isa_level = MIPS_CPU_ISA_III;
634 		c->options = R4K_OPTS |
635 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
636 			     MIPS_CPU_32FPR;
637 		c->tlbsize = 64;
638 		break;
639 	}
640 }
641 
642 static char unknown_isa[] __cpuinitdata = KERN_ERR \
643 	"Unsupported ISA type, c0.config0: %d.";
644 
645 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
646 {
647 	unsigned int config0;
648 	int isa;
649 
650 	config0 = read_c0_config();
651 
652 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
653 		c->options |= MIPS_CPU_TLB;
654 	isa = (config0 & MIPS_CONF_AT) >> 13;
655 	switch (isa) {
656 	case 0:
657 		switch ((config0 & MIPS_CONF_AR) >> 10) {
658 		case 0:
659 			c->isa_level = MIPS_CPU_ISA_M32R1;
660 			break;
661 		case 1:
662 			c->isa_level = MIPS_CPU_ISA_M32R2;
663 			break;
664 		default:
665 			goto unknown;
666 		}
667 		break;
668 	case 2:
669 		switch ((config0 & MIPS_CONF_AR) >> 10) {
670 		case 0:
671 			c->isa_level = MIPS_CPU_ISA_M64R1;
672 			break;
673 		case 1:
674 			c->isa_level = MIPS_CPU_ISA_M64R2;
675 			break;
676 		default:
677 			goto unknown;
678 		}
679 		break;
680 	default:
681 		goto unknown;
682 	}
683 
684 	return config0 & MIPS_CONF_M;
685 
686 unknown:
687 	panic(unknown_isa, config0);
688 }
689 
690 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
691 {
692 	unsigned int config1;
693 
694 	config1 = read_c0_config1();
695 
696 	if (config1 & MIPS_CONF1_MD)
697 		c->ases |= MIPS_ASE_MDMX;
698 	if (config1 & MIPS_CONF1_WR)
699 		c->options |= MIPS_CPU_WATCH;
700 	if (config1 & MIPS_CONF1_CA)
701 		c->ases |= MIPS_ASE_MIPS16;
702 	if (config1 & MIPS_CONF1_EP)
703 		c->options |= MIPS_CPU_EJTAG;
704 	if (config1 & MIPS_CONF1_FP) {
705 		c->options |= MIPS_CPU_FPU;
706 		c->options |= MIPS_CPU_32FPR;
707 	}
708 	if (cpu_has_tlb)
709 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
710 
711 	return config1 & MIPS_CONF_M;
712 }
713 
714 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
715 {
716 	unsigned int config2;
717 
718 	config2 = read_c0_config2();
719 
720 	if (config2 & MIPS_CONF2_SL)
721 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
722 
723 	return config2 & MIPS_CONF_M;
724 }
725 
726 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
727 {
728 	unsigned int config3;
729 
730 	config3 = read_c0_config3();
731 
732 	if (config3 & MIPS_CONF3_SM)
733 		c->ases |= MIPS_ASE_SMARTMIPS;
734 	if (config3 & MIPS_CONF3_DSP)
735 		c->ases |= MIPS_ASE_DSP;
736 	if (config3 & MIPS_CONF3_VINT)
737 		c->options |= MIPS_CPU_VINT;
738 	if (config3 & MIPS_CONF3_VEIC)
739 		c->options |= MIPS_CPU_VEIC;
740 	if (config3 & MIPS_CONF3_MT)
741 	        c->ases |= MIPS_ASE_MIPSMT;
742 	if (config3 & MIPS_CONF3_ULRI)
743 		c->options |= MIPS_CPU_ULRI;
744 
745 	return config3 & MIPS_CONF_M;
746 }
747 
748 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
749 {
750 	unsigned int config4;
751 
752 	config4 = read_c0_config4();
753 
754 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
755 	    && cpu_has_tlb)
756 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
757 
758 	c->kscratch_mask = (config4 >> 16) & 0xff;
759 
760 	return config4 & MIPS_CONF_M;
761 }
762 
763 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
764 {
765 	int ok;
766 
767 	/* MIPS32 or MIPS64 compliant CPU.  */
768 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
769 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
770 
771 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
772 
773 	ok = decode_config0(c);			/* Read Config registers.  */
774 	BUG_ON(!ok);				/* Arch spec violation!  */
775 	if (ok)
776 		ok = decode_config1(c);
777 	if (ok)
778 		ok = decode_config2(c);
779 	if (ok)
780 		ok = decode_config3(c);
781 	if (ok)
782 		ok = decode_config4(c);
783 
784 	mips_probe_watch_registers(c);
785 
786 	if (cpu_has_mips_r2)
787 		c->core = read_c0_ebase() & 0x3ff;
788 }
789 
790 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
791 {
792 	decode_configs(c);
793 	switch (c->processor_id & 0xff00) {
794 	case PRID_IMP_4KC:
795 		c->cputype = CPU_4KC;
796 		__cpu_name[cpu] = "MIPS 4Kc";
797 		break;
798 	case PRID_IMP_4KEC:
799 	case PRID_IMP_4KECR2:
800 		c->cputype = CPU_4KEC;
801 		__cpu_name[cpu] = "MIPS 4KEc";
802 		break;
803 	case PRID_IMP_4KSC:
804 	case PRID_IMP_4KSD:
805 		c->cputype = CPU_4KSC;
806 		__cpu_name[cpu] = "MIPS 4KSc";
807 		break;
808 	case PRID_IMP_5KC:
809 		c->cputype = CPU_5KC;
810 		__cpu_name[cpu] = "MIPS 5Kc";
811 		break;
812 	case PRID_IMP_20KC:
813 		c->cputype = CPU_20KC;
814 		__cpu_name[cpu] = "MIPS 20Kc";
815 		break;
816 	case PRID_IMP_24K:
817 	case PRID_IMP_24KE:
818 		c->cputype = CPU_24K;
819 		__cpu_name[cpu] = "MIPS 24Kc";
820 		break;
821 	case PRID_IMP_25KF:
822 		c->cputype = CPU_25KF;
823 		__cpu_name[cpu] = "MIPS 25Kc";
824 		break;
825 	case PRID_IMP_34K:
826 		c->cputype = CPU_34K;
827 		__cpu_name[cpu] = "MIPS 34Kc";
828 		break;
829 	case PRID_IMP_74K:
830 		c->cputype = CPU_74K;
831 		__cpu_name[cpu] = "MIPS 74Kc";
832 		break;
833 	case PRID_IMP_1004K:
834 		c->cputype = CPU_1004K;
835 		__cpu_name[cpu] = "MIPS 1004Kc";
836 		break;
837 	}
838 
839 	spram_config();
840 }
841 
842 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
843 {
844 	decode_configs(c);
845 	switch (c->processor_id & 0xff00) {
846 	case PRID_IMP_AU1_REV1:
847 	case PRID_IMP_AU1_REV2:
848 		c->cputype = CPU_ALCHEMY;
849 		switch ((c->processor_id >> 24) & 0xff) {
850 		case 0:
851 			__cpu_name[cpu] = "Au1000";
852 			break;
853 		case 1:
854 			__cpu_name[cpu] = "Au1500";
855 			break;
856 		case 2:
857 			__cpu_name[cpu] = "Au1100";
858 			break;
859 		case 3:
860 			__cpu_name[cpu] = "Au1550";
861 			break;
862 		case 4:
863 			__cpu_name[cpu] = "Au1200";
864 			if ((c->processor_id & 0xff) == 2)
865 				__cpu_name[cpu] = "Au1250";
866 			break;
867 		case 5:
868 			__cpu_name[cpu] = "Au1210";
869 			break;
870 		default:
871 			__cpu_name[cpu] = "Au1xxx";
872 			break;
873 		}
874 		break;
875 	}
876 }
877 
878 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
879 {
880 	decode_configs(c);
881 
882 	switch (c->processor_id & 0xff00) {
883 	case PRID_IMP_SB1:
884 		c->cputype = CPU_SB1;
885 		__cpu_name[cpu] = "SiByte SB1";
886 		/* FPU in pass1 is known to have issues. */
887 		if ((c->processor_id & 0xff) < 0x02)
888 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
889 		break;
890 	case PRID_IMP_SB1A:
891 		c->cputype = CPU_SB1A;
892 		__cpu_name[cpu] = "SiByte SB1A";
893 		break;
894 	}
895 }
896 
897 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
898 {
899 	decode_configs(c);
900 	switch (c->processor_id & 0xff00) {
901 	case PRID_IMP_SR71000:
902 		c->cputype = CPU_SR71000;
903 		__cpu_name[cpu] = "Sandcraft SR71000";
904 		c->scache.ways = 8;
905 		c->tlbsize = 64;
906 		break;
907 	}
908 }
909 
910 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
911 {
912 	decode_configs(c);
913 	switch (c->processor_id & 0xff00) {
914 	case PRID_IMP_PR4450:
915 		c->cputype = CPU_PR4450;
916 		__cpu_name[cpu] = "Philips PR4450";
917 		c->isa_level = MIPS_CPU_ISA_M32R1;
918 		break;
919 	}
920 }
921 
922 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
923 {
924 	decode_configs(c);
925 	switch (c->processor_id & 0xff00) {
926 	case PRID_IMP_BMIPS32_REV4:
927 	case PRID_IMP_BMIPS32_REV8:
928 		c->cputype = CPU_BMIPS32;
929 		__cpu_name[cpu] = "Broadcom BMIPS32";
930 		set_elf_platform(cpu, "bmips32");
931 		break;
932 	case PRID_IMP_BMIPS3300:
933 	case PRID_IMP_BMIPS3300_ALT:
934 	case PRID_IMP_BMIPS3300_BUG:
935 		c->cputype = CPU_BMIPS3300;
936 		__cpu_name[cpu] = "Broadcom BMIPS3300";
937 		set_elf_platform(cpu, "bmips3300");
938 		break;
939 	case PRID_IMP_BMIPS43XX: {
940 		int rev = c->processor_id & 0xff;
941 
942 		if (rev >= PRID_REV_BMIPS4380_LO &&
943 				rev <= PRID_REV_BMIPS4380_HI) {
944 			c->cputype = CPU_BMIPS4380;
945 			__cpu_name[cpu] = "Broadcom BMIPS4380";
946 			set_elf_platform(cpu, "bmips4380");
947 		} else {
948 			c->cputype = CPU_BMIPS4350;
949 			__cpu_name[cpu] = "Broadcom BMIPS4350";
950 			set_elf_platform(cpu, "bmips4350");
951 		}
952 		break;
953 	}
954 	case PRID_IMP_BMIPS5000:
955 		c->cputype = CPU_BMIPS5000;
956 		__cpu_name[cpu] = "Broadcom BMIPS5000";
957 		set_elf_platform(cpu, "bmips5000");
958 		c->options |= MIPS_CPU_ULRI;
959 		break;
960 	}
961 }
962 
963 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
964 {
965 	decode_configs(c);
966 	switch (c->processor_id & 0xff00) {
967 	case PRID_IMP_CAVIUM_CN38XX:
968 	case PRID_IMP_CAVIUM_CN31XX:
969 	case PRID_IMP_CAVIUM_CN30XX:
970 		c->cputype = CPU_CAVIUM_OCTEON;
971 		__cpu_name[cpu] = "Cavium Octeon";
972 		goto platform;
973 	case PRID_IMP_CAVIUM_CN58XX:
974 	case PRID_IMP_CAVIUM_CN56XX:
975 	case PRID_IMP_CAVIUM_CN50XX:
976 	case PRID_IMP_CAVIUM_CN52XX:
977 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
978 		__cpu_name[cpu] = "Cavium Octeon+";
979 platform:
980 		set_elf_platform(cpu, "octeon");
981 		break;
982 	case PRID_IMP_CAVIUM_CN61XX:
983 	case PRID_IMP_CAVIUM_CN63XX:
984 	case PRID_IMP_CAVIUM_CN66XX:
985 	case PRID_IMP_CAVIUM_CN68XX:
986 		c->cputype = CPU_CAVIUM_OCTEON2;
987 		__cpu_name[cpu] = "Cavium Octeon II";
988 		set_elf_platform(cpu, "octeon2");
989 		break;
990 	default:
991 		printk(KERN_INFO "Unknown Octeon chip!\n");
992 		c->cputype = CPU_UNKNOWN;
993 		break;
994 	}
995 }
996 
997 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
998 {
999 	decode_configs(c);
1000 	/* JZRISC does not implement the CP0 counter. */
1001 	c->options &= ~MIPS_CPU_COUNTER;
1002 	switch (c->processor_id & 0xff00) {
1003 	case PRID_IMP_JZRISC:
1004 		c->cputype = CPU_JZRISC;
1005 		__cpu_name[cpu] = "Ingenic JZRISC";
1006 		break;
1007 	default:
1008 		panic("Unknown Ingenic Processor ID!");
1009 		break;
1010 	}
1011 }
1012 
1013 static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int cpu)
1014 {
1015 	decode_configs(c);
1016 
1017 	c->options = (MIPS_CPU_TLB       |
1018 			MIPS_CPU_4KEX    |
1019 			MIPS_CPU_COUNTER |
1020 			MIPS_CPU_DIVEC   |
1021 			MIPS_CPU_WATCH   |
1022 			MIPS_CPU_EJTAG   |
1023 			MIPS_CPU_LLSC);
1024 
1025 	switch (c->processor_id & 0xff00) {
1026 	case PRID_IMP_NETLOGIC_XLR732:
1027 	case PRID_IMP_NETLOGIC_XLR716:
1028 	case PRID_IMP_NETLOGIC_XLR532:
1029 	case PRID_IMP_NETLOGIC_XLR308:
1030 	case PRID_IMP_NETLOGIC_XLR532C:
1031 	case PRID_IMP_NETLOGIC_XLR516C:
1032 	case PRID_IMP_NETLOGIC_XLR508C:
1033 	case PRID_IMP_NETLOGIC_XLR308C:
1034 		c->cputype = CPU_XLR;
1035 		__cpu_name[cpu] = "Netlogic XLR";
1036 		break;
1037 
1038 	case PRID_IMP_NETLOGIC_XLS608:
1039 	case PRID_IMP_NETLOGIC_XLS408:
1040 	case PRID_IMP_NETLOGIC_XLS404:
1041 	case PRID_IMP_NETLOGIC_XLS208:
1042 	case PRID_IMP_NETLOGIC_XLS204:
1043 	case PRID_IMP_NETLOGIC_XLS108:
1044 	case PRID_IMP_NETLOGIC_XLS104:
1045 	case PRID_IMP_NETLOGIC_XLS616B:
1046 	case PRID_IMP_NETLOGIC_XLS608B:
1047 	case PRID_IMP_NETLOGIC_XLS416B:
1048 	case PRID_IMP_NETLOGIC_XLS412B:
1049 	case PRID_IMP_NETLOGIC_XLS408B:
1050 	case PRID_IMP_NETLOGIC_XLS404B:
1051 		c->cputype = CPU_XLR;
1052 		__cpu_name[cpu] = "Netlogic XLS";
1053 		break;
1054 
1055 	default:
1056 		printk(KERN_INFO "Unknown Netlogic chip id [%02x]!\n",
1057 		       c->processor_id);
1058 		c->cputype = CPU_XLR;
1059 		break;
1060 	}
1061 
1062 	c->isa_level = MIPS_CPU_ISA_M64R1;
1063 	c->tlbsize = ((read_c0_config1() >> 25) & 0x3f) + 1;
1064 }
1065 
1066 #ifdef CONFIG_64BIT
1067 /* For use by uaccess.h */
1068 u64 __ua_limit;
1069 EXPORT_SYMBOL(__ua_limit);
1070 #endif
1071 
1072 const char *__cpu_name[NR_CPUS];
1073 const char *__elf_platform;
1074 
1075 __cpuinit void cpu_probe(void)
1076 {
1077 	struct cpuinfo_mips *c = &current_cpu_data;
1078 	unsigned int cpu = smp_processor_id();
1079 
1080 	c->processor_id	= PRID_IMP_UNKNOWN;
1081 	c->fpu_id	= FPIR_IMP_NONE;
1082 	c->cputype	= CPU_UNKNOWN;
1083 
1084 	c->processor_id = read_c0_prid();
1085 	switch (c->processor_id & 0xff0000) {
1086 	case PRID_COMP_LEGACY:
1087 		cpu_probe_legacy(c, cpu);
1088 		break;
1089 	case PRID_COMP_MIPS:
1090 		cpu_probe_mips(c, cpu);
1091 		break;
1092 	case PRID_COMP_ALCHEMY:
1093 		cpu_probe_alchemy(c, cpu);
1094 		break;
1095 	case PRID_COMP_SIBYTE:
1096 		cpu_probe_sibyte(c, cpu);
1097 		break;
1098 	case PRID_COMP_BROADCOM:
1099 		cpu_probe_broadcom(c, cpu);
1100 		break;
1101 	case PRID_COMP_SANDCRAFT:
1102 		cpu_probe_sandcraft(c, cpu);
1103 		break;
1104 	case PRID_COMP_NXP:
1105 		cpu_probe_nxp(c, cpu);
1106 		break;
1107 	case PRID_COMP_CAVIUM:
1108 		cpu_probe_cavium(c, cpu);
1109 		break;
1110 	case PRID_COMP_INGENIC:
1111 		cpu_probe_ingenic(c, cpu);
1112 		break;
1113 	case PRID_COMP_NETLOGIC:
1114 		cpu_probe_netlogic(c, cpu);
1115 		break;
1116 	}
1117 
1118 	BUG_ON(!__cpu_name[cpu]);
1119 	BUG_ON(c->cputype == CPU_UNKNOWN);
1120 
1121 	/*
1122 	 * Platform code can force the cpu type to optimize code
1123 	 * generation. In that case be sure the cpu type is correctly
1124 	 * manually setup otherwise it could trigger some nasty bugs.
1125 	 */
1126 	BUG_ON(current_cpu_type() != c->cputype);
1127 
1128 	if (mips_fpu_disabled)
1129 		c->options &= ~MIPS_CPU_FPU;
1130 
1131 	if (mips_dsp_disabled)
1132 		c->ases &= ~MIPS_ASE_DSP;
1133 
1134 	if (c->options & MIPS_CPU_FPU) {
1135 		c->fpu_id = cpu_get_fpu_id();
1136 
1137 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1138 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1139 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1140 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1141 			if (c->fpu_id & MIPS_FPIR_3D)
1142 				c->ases |= MIPS_ASE_MIPS3D;
1143 		}
1144 	}
1145 
1146 	if (cpu_has_mips_r2)
1147 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1148 	else
1149 		c->srsets = 1;
1150 
1151 	cpu_probe_vmbits(c);
1152 
1153 #ifdef CONFIG_64BIT
1154 	if (cpu == 0)
1155 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
1156 #endif
1157 }
1158 
1159 __cpuinit void cpu_report(void)
1160 {
1161 	struct cpuinfo_mips *c = &current_cpu_data;
1162 
1163 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1164 	       c->processor_id, cpu_name_string());
1165 	if (c->options & MIPS_CPU_FPU)
1166 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1167 }
1168