xref: /openbmc/linux/arch/mips/kernel/cpu-probe.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 	return;
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 /*
295  * Get the FPU Implementation/Revision.
296  */
297 static inline unsigned long cpu_get_fpu_id(void)
298 {
299 	unsigned long tmp, fpu_id;
300 
301 	tmp = read_c0_status();
302 	__enable_fpu();
303 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
304 	write_c0_status(tmp);
305 	return fpu_id;
306 }
307 
308 /*
309  * Check the CPU has an FPU the official way.
310  */
311 static inline int __cpu_has_fpu(void)
312 {
313 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
314 }
315 
316 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
317 {
318 #ifdef __NEED_VMBITS_PROBE
319 	write_c0_entryhi(0x3fffffffffffe000ULL);
320 	back_to_back_c0_hazard();
321 	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
322 #endif
323 }
324 
325 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
326 		| MIPS_CPU_COUNTER)
327 
328 static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
329 {
330 	switch (c->processor_id & 0xff00) {
331 	case PRID_IMP_R2000:
332 		c->cputype = CPU_R2000;
333 		__cpu_name[cpu] = "R2000";
334 		c->isa_level = MIPS_CPU_ISA_I;
335 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
336 		             MIPS_CPU_NOFPUEX;
337 		if (__cpu_has_fpu())
338 			c->options |= MIPS_CPU_FPU;
339 		c->tlbsize = 64;
340 		break;
341 	case PRID_IMP_R3000:
342 		if ((c->processor_id & 0xff) == PRID_REV_R3000A) {
343 			if (cpu_has_confreg()) {
344 				c->cputype = CPU_R3081E;
345 				__cpu_name[cpu] = "R3081";
346 			} else {
347 				c->cputype = CPU_R3000A;
348 				__cpu_name[cpu] = "R3000A";
349 			}
350 			break;
351 		} else {
352 			c->cputype = CPU_R3000;
353 			__cpu_name[cpu] = "R3000";
354 		}
355 		c->isa_level = MIPS_CPU_ISA_I;
356 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
357 		             MIPS_CPU_NOFPUEX;
358 		if (__cpu_has_fpu())
359 			c->options |= MIPS_CPU_FPU;
360 		c->tlbsize = 64;
361 		break;
362 	case PRID_IMP_R4000:
363 		if (read_c0_config() & CONF_SC) {
364 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
365 				c->cputype = CPU_R4400PC;
366 				__cpu_name[cpu] = "R4400PC";
367 			} else {
368 				c->cputype = CPU_R4000PC;
369 				__cpu_name[cpu] = "R4000PC";
370 			}
371 		} else {
372 			if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
373 				c->cputype = CPU_R4400SC;
374 				__cpu_name[cpu] = "R4400SC";
375 			} else {
376 				c->cputype = CPU_R4000SC;
377 				__cpu_name[cpu] = "R4000SC";
378 			}
379 		}
380 
381 		c->isa_level = MIPS_CPU_ISA_III;
382 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
383 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
384 		             MIPS_CPU_LLSC;
385 		c->tlbsize = 48;
386 		break;
387 	case PRID_IMP_VR41XX:
388 		switch (c->processor_id & 0xf0) {
389 		case PRID_REV_VR4111:
390 			c->cputype = CPU_VR4111;
391 			__cpu_name[cpu] = "NEC VR4111";
392 			break;
393 		case PRID_REV_VR4121:
394 			c->cputype = CPU_VR4121;
395 			__cpu_name[cpu] = "NEC VR4121";
396 			break;
397 		case PRID_REV_VR4122:
398 			if ((c->processor_id & 0xf) < 0x3) {
399 				c->cputype = CPU_VR4122;
400 				__cpu_name[cpu] = "NEC VR4122";
401 			} else {
402 				c->cputype = CPU_VR4181A;
403 				__cpu_name[cpu] = "NEC VR4181A";
404 			}
405 			break;
406 		case PRID_REV_VR4130:
407 			if ((c->processor_id & 0xf) < 0x4) {
408 				c->cputype = CPU_VR4131;
409 				__cpu_name[cpu] = "NEC VR4131";
410 			} else {
411 				c->cputype = CPU_VR4133;
412 				__cpu_name[cpu] = "NEC VR4133";
413 			}
414 			break;
415 		default:
416 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
417 			c->cputype = CPU_VR41XX;
418 			__cpu_name[cpu] = "NEC Vr41xx";
419 			break;
420 		}
421 		c->isa_level = MIPS_CPU_ISA_III;
422 		c->options = R4K_OPTS;
423 		c->tlbsize = 32;
424 		break;
425 	case PRID_IMP_R4300:
426 		c->cputype = CPU_R4300;
427 		__cpu_name[cpu] = "R4300";
428 		c->isa_level = MIPS_CPU_ISA_III;
429 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
430 		             MIPS_CPU_LLSC;
431 		c->tlbsize = 32;
432 		break;
433 	case PRID_IMP_R4600:
434 		c->cputype = CPU_R4600;
435 		__cpu_name[cpu] = "R4600";
436 		c->isa_level = MIPS_CPU_ISA_III;
437 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
438 			     MIPS_CPU_LLSC;
439 		c->tlbsize = 48;
440 		break;
441 	#if 0
442  	case PRID_IMP_R4650:
443 		/*
444 		 * This processor doesn't have an MMU, so it's not
445 		 * "real easy" to run Linux on it. It is left purely
446 		 * for documentation.  Commented out because it shares
447 		 * it's c0_prid id number with the TX3900.
448 		 */
449 		c->cputype = CPU_R4650;
450 		__cpu_name[cpu] = "R4650";
451 	 	c->isa_level = MIPS_CPU_ISA_III;
452 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
453 	        c->tlbsize = 48;
454 		break;
455 	#endif
456 	case PRID_IMP_TX39:
457 		c->isa_level = MIPS_CPU_ISA_I;
458 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
459 
460 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
461 			c->cputype = CPU_TX3927;
462 			__cpu_name[cpu] = "TX3927";
463 			c->tlbsize = 64;
464 		} else {
465 			switch (c->processor_id & 0xff) {
466 			case PRID_REV_TX3912:
467 				c->cputype = CPU_TX3912;
468 				__cpu_name[cpu] = "TX3912";
469 				c->tlbsize = 32;
470 				break;
471 			case PRID_REV_TX3922:
472 				c->cputype = CPU_TX3922;
473 				__cpu_name[cpu] = "TX3922";
474 				c->tlbsize = 64;
475 				break;
476 			}
477 		}
478 		break;
479 	case PRID_IMP_R4700:
480 		c->cputype = CPU_R4700;
481 		__cpu_name[cpu] = "R4700";
482 		c->isa_level = MIPS_CPU_ISA_III;
483 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
484 		             MIPS_CPU_LLSC;
485 		c->tlbsize = 48;
486 		break;
487 	case PRID_IMP_TX49:
488 		c->cputype = CPU_TX49XX;
489 		__cpu_name[cpu] = "R49XX";
490 		c->isa_level = MIPS_CPU_ISA_III;
491 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
492 		if (!(c->processor_id & 0x08))
493 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
494 		c->tlbsize = 48;
495 		break;
496 	case PRID_IMP_R5000:
497 		c->cputype = CPU_R5000;
498 		__cpu_name[cpu] = "R5000";
499 		c->isa_level = MIPS_CPU_ISA_IV;
500 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
501 		             MIPS_CPU_LLSC;
502 		c->tlbsize = 48;
503 		break;
504 	case PRID_IMP_R5432:
505 		c->cputype = CPU_R5432;
506 		__cpu_name[cpu] = "R5432";
507 		c->isa_level = MIPS_CPU_ISA_IV;
508 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
509 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
510 		c->tlbsize = 48;
511 		break;
512 	case PRID_IMP_R5500:
513 		c->cputype = CPU_R5500;
514 		__cpu_name[cpu] = "R5500";
515 		c->isa_level = MIPS_CPU_ISA_IV;
516 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
517 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
518 		c->tlbsize = 48;
519 		break;
520 	case PRID_IMP_NEVADA:
521 		c->cputype = CPU_NEVADA;
522 		__cpu_name[cpu] = "Nevada";
523 		c->isa_level = MIPS_CPU_ISA_IV;
524 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
525 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
526 		c->tlbsize = 48;
527 		break;
528 	case PRID_IMP_R6000:
529 		c->cputype = CPU_R6000;
530 		__cpu_name[cpu] = "R6000";
531 		c->isa_level = MIPS_CPU_ISA_II;
532 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
533 		             MIPS_CPU_LLSC;
534 		c->tlbsize = 32;
535 		break;
536 	case PRID_IMP_R6000A:
537 		c->cputype = CPU_R6000A;
538 		__cpu_name[cpu] = "R6000A";
539 		c->isa_level = MIPS_CPU_ISA_II;
540 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
541 		             MIPS_CPU_LLSC;
542 		c->tlbsize = 32;
543 		break;
544 	case PRID_IMP_RM7000:
545 		c->cputype = CPU_RM7000;
546 		__cpu_name[cpu] = "RM7000";
547 		c->isa_level = MIPS_CPU_ISA_IV;
548 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
549 		             MIPS_CPU_LLSC;
550 		/*
551 		 * Undocumented RM7000:  Bit 29 in the info register of
552 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
553 		 * entries.
554 		 *
555 		 * 29      1 =>    64 entry JTLB
556 		 *         0 =>    48 entry JTLB
557 		 */
558 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
559 		break;
560 	case PRID_IMP_RM9000:
561 		c->cputype = CPU_RM9000;
562 		__cpu_name[cpu] = "RM9000";
563 		c->isa_level = MIPS_CPU_ISA_IV;
564 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
565 		             MIPS_CPU_LLSC;
566 		/*
567 		 * Bit 29 in the info register of the RM9000
568 		 * indicates if the TLB has 48 or 64 entries.
569 		 *
570 		 * 29      1 =>    64 entry JTLB
571 		 *         0 =>    48 entry JTLB
572 		 */
573 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
574 		break;
575 	case PRID_IMP_R8000:
576 		c->cputype = CPU_R8000;
577 		__cpu_name[cpu] = "RM8000";
578 		c->isa_level = MIPS_CPU_ISA_IV;
579 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
580 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
581 		             MIPS_CPU_LLSC;
582 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
583 		break;
584 	case PRID_IMP_R10000:
585 		c->cputype = CPU_R10000;
586 		__cpu_name[cpu] = "R10000";
587 		c->isa_level = MIPS_CPU_ISA_IV;
588 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
589 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
590 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
591 		             MIPS_CPU_LLSC;
592 		c->tlbsize = 64;
593 		break;
594 	case PRID_IMP_R12000:
595 		c->cputype = CPU_R12000;
596 		__cpu_name[cpu] = "R12000";
597 		c->isa_level = MIPS_CPU_ISA_IV;
598 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
599 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
600 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
601 		             MIPS_CPU_LLSC;
602 		c->tlbsize = 64;
603 		break;
604 	case PRID_IMP_R14000:
605 		c->cputype = CPU_R14000;
606 		__cpu_name[cpu] = "R14000";
607 		c->isa_level = MIPS_CPU_ISA_IV;
608 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
609 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
610 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
611 		             MIPS_CPU_LLSC;
612 		c->tlbsize = 64;
613 		break;
614 	case PRID_IMP_LOONGSON2:
615 		c->cputype = CPU_LOONGSON2;
616 		__cpu_name[cpu] = "ICT Loongson-2";
617 		c->isa_level = MIPS_CPU_ISA_III;
618 		c->options = R4K_OPTS |
619 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
620 			     MIPS_CPU_32FPR;
621 		c->tlbsize = 64;
622 		break;
623 	}
624 }
625 
626 static char unknown_isa[] __cpuinitdata = KERN_ERR \
627 	"Unsupported ISA type, c0.config0: %d.";
628 
629 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
630 {
631 	unsigned int config0;
632 	int isa;
633 
634 	config0 = read_c0_config();
635 
636 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
637 		c->options |= MIPS_CPU_TLB;
638 	isa = (config0 & MIPS_CONF_AT) >> 13;
639 	switch (isa) {
640 	case 0:
641 		switch ((config0 & MIPS_CONF_AR) >> 10) {
642 		case 0:
643 			c->isa_level = MIPS_CPU_ISA_M32R1;
644 			break;
645 		case 1:
646 			c->isa_level = MIPS_CPU_ISA_M32R2;
647 			break;
648 		default:
649 			goto unknown;
650 		}
651 		break;
652 	case 2:
653 		switch ((config0 & MIPS_CONF_AR) >> 10) {
654 		case 0:
655 			c->isa_level = MIPS_CPU_ISA_M64R1;
656 			break;
657 		case 1:
658 			c->isa_level = MIPS_CPU_ISA_M64R2;
659 			break;
660 		default:
661 			goto unknown;
662 		}
663 		break;
664 	default:
665 		goto unknown;
666 	}
667 
668 	return config0 & MIPS_CONF_M;
669 
670 unknown:
671 	panic(unknown_isa, config0);
672 }
673 
674 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
675 {
676 	unsigned int config1;
677 
678 	config1 = read_c0_config1();
679 
680 	if (config1 & MIPS_CONF1_MD)
681 		c->ases |= MIPS_ASE_MDMX;
682 	if (config1 & MIPS_CONF1_WR)
683 		c->options |= MIPS_CPU_WATCH;
684 	if (config1 & MIPS_CONF1_CA)
685 		c->ases |= MIPS_ASE_MIPS16;
686 	if (config1 & MIPS_CONF1_EP)
687 		c->options |= MIPS_CPU_EJTAG;
688 	if (config1 & MIPS_CONF1_FP) {
689 		c->options |= MIPS_CPU_FPU;
690 		c->options |= MIPS_CPU_32FPR;
691 	}
692 	if (cpu_has_tlb)
693 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
694 
695 	return config1 & MIPS_CONF_M;
696 }
697 
698 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
699 {
700 	unsigned int config2;
701 
702 	config2 = read_c0_config2();
703 
704 	if (config2 & MIPS_CONF2_SL)
705 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
706 
707 	return config2 & MIPS_CONF_M;
708 }
709 
710 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
711 {
712 	unsigned int config3;
713 
714 	config3 = read_c0_config3();
715 
716 	if (config3 & MIPS_CONF3_SM)
717 		c->ases |= MIPS_ASE_SMARTMIPS;
718 	if (config3 & MIPS_CONF3_DSP)
719 		c->ases |= MIPS_ASE_DSP;
720 	if (config3 & MIPS_CONF3_VINT)
721 		c->options |= MIPS_CPU_VINT;
722 	if (config3 & MIPS_CONF3_VEIC)
723 		c->options |= MIPS_CPU_VEIC;
724 	if (config3 & MIPS_CONF3_MT)
725 	        c->ases |= MIPS_ASE_MIPSMT;
726 	if (config3 & MIPS_CONF3_ULRI)
727 		c->options |= MIPS_CPU_ULRI;
728 
729 	return config3 & MIPS_CONF_M;
730 }
731 
732 static inline unsigned int decode_config4(struct cpuinfo_mips *c)
733 {
734 	unsigned int config4;
735 
736 	config4 = read_c0_config4();
737 
738 	if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
739 	    && cpu_has_tlb)
740 		c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
741 
742 	return config4 & MIPS_CONF_M;
743 }
744 
745 static void __cpuinit decode_configs(struct cpuinfo_mips *c)
746 {
747 	int ok;
748 
749 	/* MIPS32 or MIPS64 compliant CPU.  */
750 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
751 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
752 
753 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;
754 
755 	ok = decode_config0(c);			/* Read Config registers.  */
756 	BUG_ON(!ok);				/* Arch spec violation!  */
757 	if (ok)
758 		ok = decode_config1(c);
759 	if (ok)
760 		ok = decode_config2(c);
761 	if (ok)
762 		ok = decode_config3(c);
763 	if (ok)
764 		ok = decode_config4(c);
765 
766 	mips_probe_watch_registers(c);
767 
768 	if (cpu_has_mips_r2)
769 		c->core = read_c0_ebase() & 0x3ff;
770 }
771 
772 static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
773 {
774 	decode_configs(c);
775 	switch (c->processor_id & 0xff00) {
776 	case PRID_IMP_4KC:
777 		c->cputype = CPU_4KC;
778 		__cpu_name[cpu] = "MIPS 4Kc";
779 		break;
780 	case PRID_IMP_4KEC:
781 	case PRID_IMP_4KECR2:
782 		c->cputype = CPU_4KEC;
783 		__cpu_name[cpu] = "MIPS 4KEc";
784 		break;
785 	case PRID_IMP_4KSC:
786 	case PRID_IMP_4KSD:
787 		c->cputype = CPU_4KSC;
788 		__cpu_name[cpu] = "MIPS 4KSc";
789 		break;
790 	case PRID_IMP_5KC:
791 		c->cputype = CPU_5KC;
792 		__cpu_name[cpu] = "MIPS 5Kc";
793 		break;
794 	case PRID_IMP_20KC:
795 		c->cputype = CPU_20KC;
796 		__cpu_name[cpu] = "MIPS 20Kc";
797 		break;
798 	case PRID_IMP_24K:
799 	case PRID_IMP_24KE:
800 		c->cputype = CPU_24K;
801 		__cpu_name[cpu] = "MIPS 24Kc";
802 		break;
803 	case PRID_IMP_25KF:
804 		c->cputype = CPU_25KF;
805 		__cpu_name[cpu] = "MIPS 25Kc";
806 		break;
807 	case PRID_IMP_34K:
808 		c->cputype = CPU_34K;
809 		__cpu_name[cpu] = "MIPS 34Kc";
810 		break;
811 	case PRID_IMP_74K:
812 		c->cputype = CPU_74K;
813 		__cpu_name[cpu] = "MIPS 74Kc";
814 		break;
815 	case PRID_IMP_1004K:
816 		c->cputype = CPU_1004K;
817 		__cpu_name[cpu] = "MIPS 1004Kc";
818 		break;
819 	}
820 
821 	spram_config();
822 }
823 
824 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
825 {
826 	decode_configs(c);
827 	switch (c->processor_id & 0xff00) {
828 	case PRID_IMP_AU1_REV1:
829 	case PRID_IMP_AU1_REV2:
830 		c->cputype = CPU_ALCHEMY;
831 		switch ((c->processor_id >> 24) & 0xff) {
832 		case 0:
833 			__cpu_name[cpu] = "Au1000";
834 			break;
835 		case 1:
836 			__cpu_name[cpu] = "Au1500";
837 			break;
838 		case 2:
839 			__cpu_name[cpu] = "Au1100";
840 			break;
841 		case 3:
842 			__cpu_name[cpu] = "Au1550";
843 			break;
844 		case 4:
845 			__cpu_name[cpu] = "Au1200";
846 			if ((c->processor_id & 0xff) == 2)
847 				__cpu_name[cpu] = "Au1250";
848 			break;
849 		case 5:
850 			__cpu_name[cpu] = "Au1210";
851 			break;
852 		default:
853 			__cpu_name[cpu] = "Au1xxx";
854 			break;
855 		}
856 		break;
857 	}
858 }
859 
860 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
861 {
862 	decode_configs(c);
863 
864 	switch (c->processor_id & 0xff00) {
865 	case PRID_IMP_SB1:
866 		c->cputype = CPU_SB1;
867 		__cpu_name[cpu] = "SiByte SB1";
868 		/* FPU in pass1 is known to have issues. */
869 		if ((c->processor_id & 0xff) < 0x02)
870 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
871 		break;
872 	case PRID_IMP_SB1A:
873 		c->cputype = CPU_SB1A;
874 		__cpu_name[cpu] = "SiByte SB1A";
875 		break;
876 	}
877 }
878 
879 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
880 {
881 	decode_configs(c);
882 	switch (c->processor_id & 0xff00) {
883 	case PRID_IMP_SR71000:
884 		c->cputype = CPU_SR71000;
885 		__cpu_name[cpu] = "Sandcraft SR71000";
886 		c->scache.ways = 8;
887 		c->tlbsize = 64;
888 		break;
889 	}
890 }
891 
892 static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
893 {
894 	decode_configs(c);
895 	switch (c->processor_id & 0xff00) {
896 	case PRID_IMP_PR4450:
897 		c->cputype = CPU_PR4450;
898 		__cpu_name[cpu] = "Philips PR4450";
899 		c->isa_level = MIPS_CPU_ISA_M32R1;
900 		break;
901 	}
902 }
903 
904 static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
905 {
906 	decode_configs(c);
907 	switch (c->processor_id & 0xff00) {
908 	case PRID_IMP_BMIPS32_REV4:
909 	case PRID_IMP_BMIPS32_REV8:
910 		c->cputype = CPU_BMIPS32;
911 		__cpu_name[cpu] = "Broadcom BMIPS32";
912 		break;
913 	case PRID_IMP_BMIPS3300:
914 	case PRID_IMP_BMIPS3300_ALT:
915 	case PRID_IMP_BMIPS3300_BUG:
916 		c->cputype = CPU_BMIPS3300;
917 		__cpu_name[cpu] = "Broadcom BMIPS3300";
918 		break;
919 	case PRID_IMP_BMIPS43XX: {
920 		int rev = c->processor_id & 0xff;
921 
922 		if (rev >= PRID_REV_BMIPS4380_LO &&
923 				rev <= PRID_REV_BMIPS4380_HI) {
924 			c->cputype = CPU_BMIPS4380;
925 			__cpu_name[cpu] = "Broadcom BMIPS4380";
926 		} else {
927 			c->cputype = CPU_BMIPS4350;
928 			__cpu_name[cpu] = "Broadcom BMIPS4350";
929 		}
930 		break;
931 	}
932 	case PRID_IMP_BMIPS5000:
933 		c->cputype = CPU_BMIPS5000;
934 		__cpu_name[cpu] = "Broadcom BMIPS5000";
935 		c->options |= MIPS_CPU_ULRI;
936 		break;
937 	}
938 }
939 
940 static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
941 {
942 	decode_configs(c);
943 	switch (c->processor_id & 0xff00) {
944 	case PRID_IMP_CAVIUM_CN38XX:
945 	case PRID_IMP_CAVIUM_CN31XX:
946 	case PRID_IMP_CAVIUM_CN30XX:
947 		c->cputype = CPU_CAVIUM_OCTEON;
948 		__cpu_name[cpu] = "Cavium Octeon";
949 		goto platform;
950 	case PRID_IMP_CAVIUM_CN58XX:
951 	case PRID_IMP_CAVIUM_CN56XX:
952 	case PRID_IMP_CAVIUM_CN50XX:
953 	case PRID_IMP_CAVIUM_CN52XX:
954 		c->cputype = CPU_CAVIUM_OCTEON_PLUS;
955 		__cpu_name[cpu] = "Cavium Octeon+";
956 platform:
957 		if (cpu == 0)
958 			__elf_platform = "octeon";
959 		break;
960 	case PRID_IMP_CAVIUM_CN63XX:
961 		c->cputype = CPU_CAVIUM_OCTEON2;
962 		__cpu_name[cpu] = "Cavium Octeon II";
963 		if (cpu == 0)
964 			__elf_platform = "octeon2";
965 		break;
966 	default:
967 		printk(KERN_INFO "Unknown Octeon chip!\n");
968 		c->cputype = CPU_UNKNOWN;
969 		break;
970 	}
971 }
972 
973 static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
974 {
975 	decode_configs(c);
976 	/* JZRISC does not implement the CP0 counter. */
977 	c->options &= ~MIPS_CPU_COUNTER;
978 	switch (c->processor_id & 0xff00) {
979 	case PRID_IMP_JZRISC:
980 		c->cputype = CPU_JZRISC;
981 		__cpu_name[cpu] = "Ingenic JZRISC";
982 		break;
983 	default:
984 		panic("Unknown Ingenic Processor ID!");
985 		break;
986 	}
987 }
988 
989 #ifdef CONFIG_64BIT
990 /* For use by uaccess.h */
991 u64 __ua_limit;
992 EXPORT_SYMBOL(__ua_limit);
993 #endif
994 
995 const char *__cpu_name[NR_CPUS];
996 const char *__elf_platform;
997 
998 __cpuinit void cpu_probe(void)
999 {
1000 	struct cpuinfo_mips *c = &current_cpu_data;
1001 	unsigned int cpu = smp_processor_id();
1002 
1003 	c->processor_id	= PRID_IMP_UNKNOWN;
1004 	c->fpu_id	= FPIR_IMP_NONE;
1005 	c->cputype	= CPU_UNKNOWN;
1006 
1007 	c->processor_id = read_c0_prid();
1008 	switch (c->processor_id & 0xff0000) {
1009 	case PRID_COMP_LEGACY:
1010 		cpu_probe_legacy(c, cpu);
1011 		break;
1012 	case PRID_COMP_MIPS:
1013 		cpu_probe_mips(c, cpu);
1014 		break;
1015 	case PRID_COMP_ALCHEMY:
1016 		cpu_probe_alchemy(c, cpu);
1017 		break;
1018 	case PRID_COMP_SIBYTE:
1019 		cpu_probe_sibyte(c, cpu);
1020 		break;
1021 	case PRID_COMP_BROADCOM:
1022 		cpu_probe_broadcom(c, cpu);
1023 		break;
1024 	case PRID_COMP_SANDCRAFT:
1025 		cpu_probe_sandcraft(c, cpu);
1026 		break;
1027 	case PRID_COMP_NXP:
1028 		cpu_probe_nxp(c, cpu);
1029 		break;
1030 	case PRID_COMP_CAVIUM:
1031 		cpu_probe_cavium(c, cpu);
1032 		break;
1033 	case PRID_COMP_INGENIC:
1034 		cpu_probe_ingenic(c, cpu);
1035 		break;
1036 	}
1037 
1038 	BUG_ON(!__cpu_name[cpu]);
1039 	BUG_ON(c->cputype == CPU_UNKNOWN);
1040 
1041 	/*
1042 	 * Platform code can force the cpu type to optimize code
1043 	 * generation. In that case be sure the cpu type is correctly
1044 	 * manually setup otherwise it could trigger some nasty bugs.
1045 	 */
1046 	BUG_ON(current_cpu_type() != c->cputype);
1047 
1048 	if (mips_fpu_disabled)
1049 		c->options &= ~MIPS_CPU_FPU;
1050 
1051 	if (mips_dsp_disabled)
1052 		c->ases &= ~MIPS_ASE_DSP;
1053 
1054 	if (c->options & MIPS_CPU_FPU) {
1055 		c->fpu_id = cpu_get_fpu_id();
1056 
1057 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
1058 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
1059 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
1060 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
1061 			if (c->fpu_id & MIPS_FPIR_3D)
1062 				c->ases |= MIPS_ASE_MIPS3D;
1063 		}
1064 	}
1065 
1066 	if (cpu_has_mips_r2)
1067 		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1068 	else
1069 		c->srsets = 1;
1070 
1071 	cpu_probe_vmbits(c);
1072 
1073 #ifdef CONFIG_64BIT
1074 	if (cpu == 0)
1075 		__ua_limit = ~((1ull << cpu_vmbits) - 1);
1076 #endif
1077 }
1078 
1079 __cpuinit void cpu_report(void)
1080 {
1081 	struct cpuinfo_mips *c = &current_cpu_data;
1082 
1083 	printk(KERN_INFO "CPU revision is: %08x (%s)\n",
1084 	       c->processor_id, cpu_name_string());
1085 	if (c->options & MIPS_CPU_FPU)
1086 		printk(KERN_INFO "FPU revision is: %08x\n", c->fpu_id);
1087 }
1088