arch/mips/kernel/cpu-probe.c - linux - Git at Google

 /*
  * Processor capabilities determination functions.
  *
  * Copyright (C) xxxx  the Anonymous
  * Copyright (C) 1994 - 2006 Ralf Baechle
  * Copyright (C) 2003, 2004  Maciej W. Rozycki
  * Copyright (C) 2001, 2004  MIPS Inc.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/ptrace.h>
 #include <linux/stddef.h>

 #include <asm/bugs.h>
 #include <asm/cpu.h>
 #include <asm/fpu.h>
 #include <asm/mipsregs.h>
 #include <asm/system.h>

 /*
  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
  * the implementation of the "wait" feature differs between CPU families. This
  * points to the function that implements CPU specific wait.
  * The wait instruction stops the pipeline and reduces the power consumption of
  * the CPU very much.
  */
 void (*cpu_wait)(void) = NULL;

 static void r3081_wait(void)
 {
 	unsigned long cfg = read_c0_conf();
 	write_c0_conf(cfg | R30XX_CONF_HALT);
 }

 static void r39xx_wait(void)
 {
 	local_irq_disable();
 	if (!need_resched())
 		write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
 	local_irq_enable();
 }

 /*
  * There is a race when WAIT instruction executed with interrupt
  * enabled.
  * But it is implementation-dependent wheter the pipelie restarts when
  * a non-enabled interrupt is requested.
  */
 static void r4k_wait(void)
 {
 	__asm__("	.set	mips3			\n"
 		"	wait				\n"
 		"	.set	mips0			\n");
 }

 /*
  * This variant is preferable as it allows testing need_resched and going to
  * sleep depending on the outcome atomically.  Unfortunately the "It is
  * implementation-dependent whether the pipeline restarts when a non-enabled
  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
  * using this version a gamble.
  */
 static void r4k_wait_irqoff(void)
 {
 	local_irq_disable();
 	if (!need_resched())
 		__asm__("	.set	mips3		\n"
 			"	wait			\n"
 			"	.set	mips0		\n");
 	local_irq_enable();
 }

 /* The Au1xxx wait is available only if using 32khz counter or
  * external timer source, but specifically not CP0 Counter. */
 int allow_au1k_wait;

 static void au1k_wait(void)
 {
 	/* using the wait instruction makes CP0 counter unusable */
 	__asm__("	.set	mips3			\n"
 		"	cache	0x14, 0(%0)		\n"
 		"	cache	0x14, 32(%0)		\n"
 		"	sync				\n"
 		"	nop				\n"
 		"	wait				\n"
 		"	nop				\n"
 		"	nop				\n"
 		"	nop				\n"
 		"	nop				\n"
 		"	.set	mips0			\n"
 		: : "r" (au1k_wait));
 }

 static int __initdata nowait = 0;

 static int __init wait_disable(char *s)
 {
 	nowait = 1;

 	return 1;
 }

 __setup("nowait", wait_disable);

 static inline void check_wait(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;

 	if (nowait) {
 		printk("Wait instruction disabled.\n");
 		return;
 	}

 	switch (c->cputype) {
 	case CPU_R3081:
 	case CPU_R3081E:
 		cpu_wait = r3081_wait;
 		break;
 	case CPU_TX3927:
 		cpu_wait = r39xx_wait;
 		break;
 	case CPU_R4200:
 /*	case CPU_R4300: */
 	case CPU_R4600:
 	case CPU_R4640:
 	case CPU_R4650:
 	case CPU_R4700:
 	case CPU_R5000:
 	case CPU_NEVADA:
 	case CPU_RM7000:
 	case CPU_4KC:
 	case CPU_4KEC:
 	case CPU_4KSC:
 	case CPU_5KC:
 	case CPU_25KF:
 	case CPU_PR4450:
 		cpu_wait = r4k_wait;
 		break;

 	case CPU_24K:
 	case CPU_34K:
 		cpu_wait = r4k_wait;
 		if (read_c0_config7() & MIPS_CONF7_WII)
 			cpu_wait = r4k_wait_irqoff;
 		break;

 	case CPU_74K:
 		cpu_wait = r4k_wait;
 		if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
 			cpu_wait = r4k_wait_irqoff;
 		break;

 	case CPU_TX49XX:
 		cpu_wait = r4k_wait_irqoff;
 		break;
 	case CPU_AU1000:
 	case CPU_AU1100:
 	case CPU_AU1500:
 	case CPU_AU1550:
 	case CPU_AU1200:
 		if (allow_au1k_wait)
 			cpu_wait = au1k_wait;
 		break;
 	case CPU_20KC:
 		/*
 		 * WAIT on Rev1.0 has E1, E2, E3 and E16.
 		 * WAIT on Rev2.0 and Rev3.0 has E16.
 		 * Rev3.1 WAIT is nop, why bother
 		 */
 		if ((c->processor_id & 0xff) <= 0x64)
 			break;

 		cpu_wait = r4k_wait;
 		break;
 	case CPU_RM9000:
 		if ((c->processor_id & 0x00ff) >= 0x40)
 			cpu_wait = r4k_wait;
 		break;
 	default:
 		break;
 	}
 }

 void __init check_bugs32(void)
 {
 	check_wait();
 }

 /*
  * Probe whether cpu has config register by trying to play with
  * alternate cache bit and see whether it matters.
  * It's used by cpu_probe to distinguish between R3000A and R3081.
  */
 static inline int cpu_has_confreg(void)
 {
 #ifdef CONFIG_CPU_R3000
 	extern unsigned long r3k_cache_size(unsigned long);
 	unsigned long size1, size2;
 	unsigned long cfg = read_c0_conf();

 	size1 = r3k_cache_size(ST0_ISC);
 	write_c0_conf(cfg ^ R30XX_CONF_AC);
 	size2 = r3k_cache_size(ST0_ISC);
 	write_c0_conf(cfg);
 	return size1 != size2;
 #else
 	return 0;
 #endif
 }

 /*
  * Get the FPU Implementation/Revision.
  */
 static inline unsigned long cpu_get_fpu_id(void)
 {
 	unsigned long tmp, fpu_id;

 	tmp = read_c0_status();
 	__enable_fpu();
 	fpu_id = read_32bit_cp1_register(CP1_REVISION);
 	write_c0_status(tmp);
 	return fpu_id;
 }

 /*
  * Check the CPU has an FPU the official way.
  */
 static inline int __cpu_has_fpu(void)
 {
 	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
 }

 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
 		| MIPS_CPU_COUNTER)

 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
 {
 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_R2000:
 		c->cputype = CPU_R2000;
 		c->isa_level = MIPS_CPU_ISA_I;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 		             MIPS_CPU_NOFPUEX;
 		if (__cpu_has_fpu())
 			c->options |= MIPS_CPU_FPU;
 		c->tlbsize = 64;
 		break;
 	case PRID_IMP_R3000:
 		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
 			if (cpu_has_confreg())
 				c->cputype = CPU_R3081E;
 			else
 				c->cputype = CPU_R3000A;
 		else
 			c->cputype = CPU_R3000;
 		c->isa_level = MIPS_CPU_ISA_I;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 		             MIPS_CPU_NOFPUEX;
 		if (__cpu_has_fpu())
 			c->options |= MIPS_CPU_FPU;
 		c->tlbsize = 64;
 		break;
 	case PRID_IMP_R4000:
 		if (read_c0_config() & CONF_SC) {
 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 				c->cputype = CPU_R4400PC;
 			else
 				c->cputype = CPU_R4000PC;
 		} else {
 			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 				c->cputype = CPU_R4400SC;
 			else
 				c->cputype = CPU_R4000SC;
 		}

 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_VR41XX:
 		switch (c->processor_id & 0xf0) {
 		case PRID_REV_VR4111:
 			c->cputype = CPU_VR4111;
 			break;
 		case PRID_REV_VR4121:
 			c->cputype = CPU_VR4121;
 			break;
 		case PRID_REV_VR4122:
 			if ((c->processor_id & 0xf) < 0x3)
 				c->cputype = CPU_VR4122;
 			else
 				c->cputype = CPU_VR4181A;
 			break;
 		case PRID_REV_VR4130:
 			if ((c->processor_id & 0xf) < 0x4)
 				c->cputype = CPU_VR4131;
 			else
 				c->cputype = CPU_VR4133;
 			break;
 		default:
 			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 			c->cputype = CPU_VR41XX;
 			break;
 		}
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS;
 		c->tlbsize = 32;
 		break;
 	case PRID_IMP_R4300:
 		c->cputype = CPU_R4300;
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 32;
 		break;
 	case PRID_IMP_R4600:
 		c->cputype = CPU_R4600;
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 			     MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	#if 0
  	case PRID_IMP_R4650:
 		/*
 		 * This processor doesn't have an MMU, so it's not
 		 * "real easy" to run Linux on it. It is left purely
 		 * for documentation.  Commented out because it shares
 		 * it's c0_prid id number with the TX3900.
 		 */
 		c->cputype = CPU_R4650;
 	 	c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 	        c->tlbsize = 48;
 		break;
 	#endif
 	case PRID_IMP_TX39:
 		c->isa_level = MIPS_CPU_ISA_I;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;

 		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 			c->cputype = CPU_TX3927;
 			c->tlbsize = 64;
 		} else {
 			switch (c->processor_id & 0xff) {
 			case PRID_REV_TX3912:
 				c->cputype = CPU_TX3912;
 				c->tlbsize = 32;
 				break;
 			case PRID_REV_TX3922:
 				c->cputype = CPU_TX3922;
 				c->tlbsize = 64;
 				break;
 			default:
 				c->cputype = CPU_UNKNOWN;
 				break;
 			}
 		}
 		break;
 	case PRID_IMP_R4700:
 		c->cputype = CPU_R4700;
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_TX49:
 		c->cputype = CPU_TX49XX;
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS | MIPS_CPU_LLSC;
 		if (!(c->processor_id & 0x08))
 			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_R5000:
 		c->cputype = CPU_R5000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_R5432:
 		c->cputype = CPU_R5432;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_R5500:
 		c->cputype = CPU_R5500;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_NEVADA:
 		c->cputype = CPU_NEVADA;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_R6000:
 		c->cputype = CPU_R6000;
 		c->isa_level = MIPS_CPU_ISA_II;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 32;
 		break;
 	case PRID_IMP_R6000A:
 		c->cputype = CPU_R6000A;
 		c->isa_level = MIPS_CPU_ISA_II;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 32;
 		break;
 	case PRID_IMP_RM7000:
 		c->cputype = CPU_RM7000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		/*
 		 * Undocumented RM7000:  Bit 29 in the info register of
 		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
 		 * entries.
 		 *
 		 * 29      1 =>    64 entry JTLB
 		 *         0 =>    48 entry JTLB
 		 */
 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 		break;
 	case PRID_IMP_RM9000:
 		c->cputype = CPU_RM9000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		/*
 		 * Bit 29 in the info register of the RM9000
 		 * indicates if the TLB has 48 or 64 entries.
 		 *
 		 * 29      1 =>    64 entry JTLB
 		 *         0 =>    48 entry JTLB
 		 */
 		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 		break;
 	case PRID_IMP_R8000:
 		c->cputype = CPU_R8000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 		break;
 	case PRID_IMP_R10000:
 		c->cputype = CPU_R10000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 64;
 		break;
 	case PRID_IMP_R12000:
 		c->cputype = CPU_R12000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 64;
 		break;
 	case PRID_IMP_R14000:
 		c->cputype = CPU_R14000;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
 			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 		             MIPS_CPU_LLSC;
 		c->tlbsize = 64;
 		break;
 	case PRID_IMP_LOONGSON2:
 		c->cputype = CPU_LOONGSON2;
 		c->isa_level = MIPS_CPU_ISA_III;
 		c->options = R4K_OPTS |
 			     MIPS_CPU_FPU | MIPS_CPU_LLSC |
 			     MIPS_CPU_32FPR;
 		c->tlbsize = 64;
 		break;
 	}
 }

 static char unknown_isa[] __initdata = KERN_ERR \
 	"Unsupported ISA type, c0.config0: %d.";

 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
 {
 	unsigned int config0;
 	int isa;

 	config0 = read_c0_config();

 	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
 		c->options |= MIPS_CPU_TLB;
 	isa = (config0 & MIPS_CONF_AT) >> 13;
 	switch (isa) {
 	case 0:
 		switch ((config0 & MIPS_CONF_AR) >> 10) {
 		case 0:
 			c->isa_level = MIPS_CPU_ISA_M32R1;
 			break;
 		case 1:
 			c->isa_level = MIPS_CPU_ISA_M32R2;
 			break;
 		default:
 			goto unknown;
 		}
 		break;
 	case 2:
 		switch ((config0 & MIPS_CONF_AR) >> 10) {
 		case 0:
 			c->isa_level = MIPS_CPU_ISA_M64R1;
 			break;
 		case 1:
 			c->isa_level = MIPS_CPU_ISA_M64R2;
 			break;
 		default:
 			goto unknown;
 		}
 		break;
 	default:
 		goto unknown;
 	}

 	return config0 & MIPS_CONF_M;

 unknown:
 	panic(unknown_isa, config0);
 }

 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
 {
 	unsigned int config1;

 	config1 = read_c0_config1();

 	if (config1 & MIPS_CONF1_MD)
 		c->ases |= MIPS_ASE_MDMX;
 	if (config1 & MIPS_CONF1_WR)
 		c->options |= MIPS_CPU_WATCH;
 	if (config1 & MIPS_CONF1_CA)
 		c->ases |= MIPS_ASE_MIPS16;
 	if (config1 & MIPS_CONF1_EP)
 		c->options |= MIPS_CPU_EJTAG;
 	if (config1 & MIPS_CONF1_FP) {
 		c->options |= MIPS_CPU_FPU;
 		c->options |= MIPS_CPU_32FPR;
 	}
 	if (cpu_has_tlb)
 		c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;

 	return config1 & MIPS_CONF_M;
 }

 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
 {
 	unsigned int config2;

 	config2 = read_c0_config2();

 	if (config2 & MIPS_CONF2_SL)
 		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;

 	return config2 & MIPS_CONF_M;
 }

 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
 {
 	unsigned int config3;

 	config3 = read_c0_config3();

 	if (config3 & MIPS_CONF3_SM)
 		c->ases |= MIPS_ASE_SMARTMIPS;
 	if (config3 & MIPS_CONF3_DSP)
 		c->ases |= MIPS_ASE_DSP;
 	if (config3 & MIPS_CONF3_VINT)
 		c->options |= MIPS_CPU_VINT;
 	if (config3 & MIPS_CONF3_VEIC)
 		c->options |= MIPS_CPU_VEIC;
 	if (config3 & MIPS_CONF3_MT)
 	        c->ases |= MIPS_ASE_MIPSMT;
 	if (config3 & MIPS_CONF3_ULRI)
 		c->options |= MIPS_CPU_ULRI;

 	return config3 & MIPS_CONF_M;
 }

 static void __init decode_configs(struct cpuinfo_mips *c)
 {
 	/* MIPS32 or MIPS64 compliant CPU.  */
 	c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
 	             MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;

 	c->scache.flags = MIPS_CACHE_NOT_PRESENT;

 	/* Read Config registers.  */
 	if (!decode_config0(c))
 		return;			/* actually worth a panic() */
 	if (!decode_config1(c))
 		return;
 	if (!decode_config2(c))
 		return;
 	if (!decode_config3(c))
 		return;
 }

 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 {
 	decode_configs(c);
 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_4KC:
 		c->cputype = CPU_4KC;
 		break;
 	case PRID_IMP_4KEC:
 		c->cputype = CPU_4KEC;
 		break;
 	case PRID_IMP_4KECR2:
 		c->cputype = CPU_4KEC;
 		break;
 	case PRID_IMP_4KSC:
 	case PRID_IMP_4KSD:
 		c->cputype = CPU_4KSC;
 		break;
 	case PRID_IMP_5KC:
 		c->cputype = CPU_5KC;
 		break;
 	case PRID_IMP_20KC:
 		c->cputype = CPU_20KC;
 		break;
 	case PRID_IMP_24K:
 	case PRID_IMP_24KE:
 		c->cputype = CPU_24K;
 		break;
 	case PRID_IMP_25KF:
 		c->cputype = CPU_25KF;
 		break;
 	case PRID_IMP_34K:
 		c->cputype = CPU_34K;
 		break;
 	case PRID_IMP_74K:
 		c->cputype = CPU_74K;
 		break;
 	}
 }

 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 {
 	decode_configs(c);
 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_AU1_REV1:
 	case PRID_IMP_AU1_REV2:
 		switch ((c->processor_id >> 24) & 0xff) {
 		case 0:
 			c->cputype = CPU_AU1000;
 			break;
 		case 1:
 			c->cputype = CPU_AU1500;
 			break;
 		case 2:
 			c->cputype = CPU_AU1100;
 			break;
 		case 3:
 			c->cputype = CPU_AU1550;
 			break;
 		case 4:
 			c->cputype = CPU_AU1200;
 			break;
 		default:
 			panic("Unknown Au Core!");
 			break;
 		}
 		break;
 	}
 }

 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 {
 	decode_configs(c);

 	/*
 	 * For historical reasons the SB1 comes with it's own variant of
 	 * cache code which eventually will be folded into c-r4k.c.  Until
 	 * then we pretend it's got it's own cache architecture.
 	 */
 	c->options &= ~MIPS_CPU_4K_CACHE;
 	c->options |= MIPS_CPU_SB1_CACHE;

 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_SB1:
 		c->cputype = CPU_SB1;
 		/* FPU in pass1 is known to have issues. */
 		if ((c->processor_id & 0xff) < 0x02)
 			c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
 		break;
 	case PRID_IMP_SB1A:
 		c->cputype = CPU_SB1A;
 		break;
 	}
 }

 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 {
 	decode_configs(c);
 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_SR71000:
 		c->cputype = CPU_SR71000;
 		c->scache.ways = 8;
 		c->tlbsize = 64;
 		break;
 	}
 }

 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
 {
 	decode_configs(c);
 	switch (c->processor_id & 0xff00) {
 	case PRID_IMP_PR4450:
 		c->cputype = CPU_PR4450;
 		c->isa_level = MIPS_CPU_ISA_M32R1;
 		break;
 	default:
 		panic("Unknown Philips Core!"); /* REVISIT: die? */
 		break;
 	}
 }


 __init void cpu_probe(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;

 	c->processor_id	= PRID_IMP_UNKNOWN;
 	c->fpu_id	= FPIR_IMP_NONE;
 	c->cputype	= CPU_UNKNOWN;

 	c->processor_id = read_c0_prid();
 	switch (c->processor_id & 0xff0000) {
 	case PRID_COMP_LEGACY:
 		cpu_probe_legacy(c);
 		break;
 	case PRID_COMP_MIPS:
 		cpu_probe_mips(c);
 		break;
 	case PRID_COMP_ALCHEMY:
 		cpu_probe_alchemy(c);
 		break;
 	case PRID_COMP_SIBYTE:
 		cpu_probe_sibyte(c);
 		break;
 	case PRID_COMP_SANDCRAFT:
 		cpu_probe_sandcraft(c);
 		break;
  	case PRID_COMP_PHILIPS:
 		cpu_probe_philips(c);
 		break;
 	default:
 		c->cputype = CPU_UNKNOWN;
 	}
 	if (c->options & MIPS_CPU_FPU) {
 		c->fpu_id = cpu_get_fpu_id();

 		if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
 		    c->isa_level == MIPS_CPU_ISA_M32R2 ||
 		    c->isa_level == MIPS_CPU_ISA_M64R1 ||
 		    c->isa_level == MIPS_CPU_ISA_M64R2) {
 			if (c->fpu_id & MIPS_FPIR_3D)
 				c->ases |= MIPS_ASE_MIPS3D;
 		}
 	}
 }

 __init void cpu_report(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;

 	printk("CPU revision is: %08x\n", c->processor_id);
 	if (c->options & MIPS_CPU_FPU)
 		printk("FPU revision is: %08x\n", c->fpu_id);
 }
	/*
	* Processor capabilities determination functions.
	*
	* Copyright (C) xxxx the Anonymous
	* Copyright (C) 1994 - 2006 Ralf Baechle
	* Copyright (C) 2003, 2004 Maciej W. Rozycki
	* Copyright (C) 2001, 2004 MIPS Inc.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/ptrace.h>
	#include <linux/stddef.h>

	#include <asm/bugs.h>
	#include <asm/cpu.h>
	#include <asm/fpu.h>
	#include <asm/mipsregs.h>
	#include <asm/system.h>

	/*
	* Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
	* the implementation of the "wait" feature differs between CPU families. This
	* points to the function that implements CPU specific wait.
	* The wait instruction stops the pipeline and reduces the power consumption of
	* the CPU very much.
	*/
	void (*cpu_wait)(void) = NULL;

	static void r3081_wait(void)
	{
	unsigned long cfg = read_c0_conf();
	write_c0_conf(cfg \| R30XX_CONF_HALT);
	}

	static void r39xx_wait(void)
	{
	local_irq_disable();
	if (!need_resched())
	write_c0_conf(read_c0_conf() \| TX39_CONF_HALT);
	local_irq_enable();
	}

	/*
	* There is a race when WAIT instruction executed with interrupt
	* enabled.
	* But it is implementation-dependent wheter the pipelie restarts when
	* a non-enabled interrupt is requested.
	*/
	static void r4k_wait(void)
	{
	__asm__(" .set mips3 \n"
	" wait \n"
	" .set mips0 \n");
	}

	/*
	* This variant is preferable as it allows testing need_resched and going to
	* sleep depending on the outcome atomically. Unfortunately the "It is
	* implementation-dependent whether the pipeline restarts when a non-enabled
	* interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
	* using this version a gamble.
	*/
	static void r4k_wait_irqoff(void)
	{
	local_irq_disable();
	if (!need_resched())
	__asm__(" .set mips3 \n"
	" wait \n"
	" .set mips0 \n");
	local_irq_enable();
	}

	/* The Au1xxx wait is available only if using 32khz counter or
	* external timer source, but specifically not CP0 Counter. */
	int allow_au1k_wait;

	static void au1k_wait(void)
	{
	/* using the wait instruction makes CP0 counter unusable */
	__asm__(" .set mips3 \n"
	" cache 0x14, 0(%0) \n"
	" cache 0x14, 32(%0) \n"
	" sync \n"
	" nop \n"
	" wait \n"
	" nop \n"
	" nop \n"
	" nop \n"
	" nop \n"
	" .set mips0 \n"
	: : "r" (au1k_wait));
	}

	static int __initdata nowait = 0;

	static int __init wait_disable(char *s)
	{
	nowait = 1;

	return 1;
	}

	__setup("nowait", wait_disable);

	static inline void check_wait(void)
	{
	struct cpuinfo_mips *c = &current_cpu_data;

	if (nowait) {
	printk("Wait instruction disabled.\n");
	return;
	}

	switch (c->cputype) {
	case CPU_R3081:
	case CPU_R3081E:
	cpu_wait = r3081_wait;
	break;
	case CPU_TX3927:
	cpu_wait = r39xx_wait;
	break;
	case CPU_R4200:
	/* case CPU_R4300: */
	case CPU_R4600:
	case CPU_R4640:
	case CPU_R4650:
	case CPU_R4700:
	case CPU_R5000:
	case CPU_NEVADA:
	case CPU_RM7000:
	case CPU_4KC:
	case CPU_4KEC:
	case CPU_4KSC:
	case CPU_5KC:
	case CPU_25KF:
	case CPU_PR4450:
	cpu_wait = r4k_wait;
	break;

	case CPU_24K:
	case CPU_34K:
	cpu_wait = r4k_wait;
	if (read_c0_config7() & MIPS_CONF7_WII)
	cpu_wait = r4k_wait_irqoff;
	break;

	case CPU_74K:
	cpu_wait = r4k_wait;
	if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
	cpu_wait = r4k_wait_irqoff;
	break;

	case CPU_TX49XX:
	cpu_wait = r4k_wait_irqoff;
	break;
	case CPU_AU1000:
	case CPU_AU1100:
	case CPU_AU1500:
	case CPU_AU1550:
	case CPU_AU1200:
	if (allow_au1k_wait)
	cpu_wait = au1k_wait;
	break;
	case CPU_20KC:
	/*
	* WAIT on Rev1.0 has E1, E2, E3 and E16.
	* WAIT on Rev2.0 and Rev3.0 has E16.
	* Rev3.1 WAIT is nop, why bother
	*/
	if ((c->processor_id & 0xff) <= 0x64)
	break;

	cpu_wait = r4k_wait;
	break;
	case CPU_RM9000:
	if ((c->processor_id & 0x00ff) >= 0x40)
	cpu_wait = r4k_wait;
	break;
	default:
	break;
	}
	}

	void __init check_bugs32(void)
	{
	check_wait();
	}

	/*
	* Probe whether cpu has config register by trying to play with
	* alternate cache bit and see whether it matters.
	* It's used by cpu_probe to distinguish between R3000A and R3081.
	*/
	static inline int cpu_has_confreg(void)
	{
	#ifdef CONFIG_CPU_R3000
	extern unsigned long r3k_cache_size(unsigned long);
	unsigned long size1, size2;
	unsigned long cfg = read_c0_conf();

	size1 = r3k_cache_size(ST0_ISC);
	write_c0_conf(cfg ^ R30XX_CONF_AC);
	size2 = r3k_cache_size(ST0_ISC);
	write_c0_conf(cfg);
	return size1 != size2;
	#else
	return 0;
	#endif
	}

	/*
	* Get the FPU Implementation/Revision.
	*/
	static inline unsigned long cpu_get_fpu_id(void)
	{
	unsigned long tmp, fpu_id;

	tmp = read_c0_status();
	__enable_fpu();
	fpu_id = read_32bit_cp1_register(CP1_REVISION);
	write_c0_status(tmp);
	return fpu_id;
	}

	/*
	* Check the CPU has an FPU the official way.
	*/
	static inline int __cpu_has_fpu(void)
	{
	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
	}

	#define R4K_OPTS (MIPS_CPU_TLB \| MIPS_CPU_4KEX \| MIPS_CPU_4K_CACHE \
	\| MIPS_CPU_COUNTER)

	static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
	{
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_R2000:
	c->cputype = CPU_R2000;
	c->isa_level = MIPS_CPU_ISA_I;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_3K_CACHE \|
	MIPS_CPU_NOFPUEX;
	if (__cpu_has_fpu())
	c->options \|= MIPS_CPU_FPU;
	c->tlbsize = 64;
	break;
	case PRID_IMP_R3000:
	if ((c->processor_id & 0xff) == PRID_REV_R3000A)
	if (cpu_has_confreg())
	c->cputype = CPU_R3081E;
	else
	c->cputype = CPU_R3000A;
	else
	c->cputype = CPU_R3000;
	c->isa_level = MIPS_CPU_ISA_I;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_3K_CACHE \|
	MIPS_CPU_NOFPUEX;
	if (__cpu_has_fpu())
	c->options \|= MIPS_CPU_FPU;
	c->tlbsize = 64;
	break;
	case PRID_IMP_R4000:
	if (read_c0_config() & CONF_SC) {
	if ((c->processor_id & 0xff) >= PRID_REV_R4400)
	c->cputype = CPU_R4400PC;
	else
	c->cputype = CPU_R4000PC;
	} else {
	if ((c->processor_id & 0xff) >= PRID_REV_R4400)
	c->cputype = CPU_R4400SC;
	else
	c->cputype = CPU_R4000SC;
	}

	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_WATCH \| MIPS_CPU_VCE \|
	MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_VR41XX:
	switch (c->processor_id & 0xf0) {
	case PRID_REV_VR4111:
	c->cputype = CPU_VR4111;
	break;
	case PRID_REV_VR4121:
	c->cputype = CPU_VR4121;
	break;
	case PRID_REV_VR4122:
	if ((c->processor_id & 0xf) < 0x3)
	c->cputype = CPU_VR4122;
	else
	c->cputype = CPU_VR4181A;
	break;
	case PRID_REV_VR4130:
	if ((c->processor_id & 0xf) < 0x4)
	c->cputype = CPU_VR4131;
	else
	c->cputype = CPU_VR4133;
	break;
	default:
	printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
	c->cputype = CPU_VR41XX;
	break;
	}
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS;
	c->tlbsize = 32;
	break;
	case PRID_IMP_R4300:
	c->cputype = CPU_R4300;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	c->tlbsize = 32;
	break;
	case PRID_IMP_R4600:
	c->cputype = CPU_R4600;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	#if 0
	case PRID_IMP_R4650:
	/*
	* This processor doesn't have an MMU, so it's not
	* "real easy" to run Linux on it. It is left purely
	* for documentation. Commented out because it shares
	* it's c0_prid id number with the TX3900.
	*/
	c->cputype = CPU_R4650;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	#endif
	case PRID_IMP_TX39:
	c->isa_level = MIPS_CPU_ISA_I;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_TX39_CACHE;

	if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
	c->cputype = CPU_TX3927;
	c->tlbsize = 64;
	} else {
	switch (c->processor_id & 0xff) {
	case PRID_REV_TX3912:
	c->cputype = CPU_TX3912;
	c->tlbsize = 32;
	break;
	case PRID_REV_TX3922:
	c->cputype = CPU_TX3922;
	c->tlbsize = 64;
	break;
	default:
	c->cputype = CPU_UNKNOWN;
	break;
	}
	}
	break;
	case PRID_IMP_R4700:
	c->cputype = CPU_R4700;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_TX49:
	c->cputype = CPU_TX49XX;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \| MIPS_CPU_LLSC;
	if (!(c->processor_id & 0x08))
	c->options \|= MIPS_CPU_FPU \| MIPS_CPU_32FPR;
	c->tlbsize = 48;
	break;
	case PRID_IMP_R5000:
	c->cputype = CPU_R5000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_R5432:
	c->cputype = CPU_R5432;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_WATCH \| MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_R5500:
	c->cputype = CPU_R5500;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_WATCH \| MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_NEVADA:
	c->cputype = CPU_NEVADA;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_DIVEC \| MIPS_CPU_LLSC;
	c->tlbsize = 48;
	break;
	case PRID_IMP_R6000:
	c->cputype = CPU_R6000;
	c->isa_level = MIPS_CPU_ISA_II;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_FPU \|
	MIPS_CPU_LLSC;
	c->tlbsize = 32;
	break;
	case PRID_IMP_R6000A:
	c->cputype = CPU_R6000A;
	c->isa_level = MIPS_CPU_ISA_II;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_FPU \|
	MIPS_CPU_LLSC;
	c->tlbsize = 32;
	break;
	case PRID_IMP_RM7000:
	c->cputype = CPU_RM7000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	/*
	* Undocumented RM7000: Bit 29 in the info register of
	* the RM7000 v2.0 indicates if the TLB has 48 or 64
	* entries.
	*
	* 29 1 => 64 entry JTLB
	* 0 => 48 entry JTLB
	*/
	c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
	break;
	case PRID_IMP_RM9000:
	c->cputype = CPU_RM9000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = R4K_OPTS \| MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	/*
	* Bit 29 in the info register of the RM9000
	* indicates if the TLB has 48 or 64 entries.
	*
	* 29 1 => 64 entry JTLB
	* 0 => 48 entry JTLB
	*/
	c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
	break;
	case PRID_IMP_R8000:
	c->cputype = CPU_R8000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_4KEX \|
	MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_LLSC;
	c->tlbsize = 384; /* has weird TLB: 3-way x 128 */
	break;
	case PRID_IMP_R10000:
	c->cputype = CPU_R10000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_4K_CACHE \| MIPS_CPU_4KEX \|
	MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_COUNTER \| MIPS_CPU_WATCH \|
	MIPS_CPU_LLSC;
	c->tlbsize = 64;
	break;
	case PRID_IMP_R12000:
	c->cputype = CPU_R12000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_4K_CACHE \| MIPS_CPU_4KEX \|
	MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_COUNTER \| MIPS_CPU_WATCH \|
	MIPS_CPU_LLSC;
	c->tlbsize = 64;
	break;
	case PRID_IMP_R14000:
	c->cputype = CPU_R14000;
	c->isa_level = MIPS_CPU_ISA_IV;
	c->options = MIPS_CPU_TLB \| MIPS_CPU_4K_CACHE \| MIPS_CPU_4KEX \|
	MIPS_CPU_FPU \| MIPS_CPU_32FPR \|
	MIPS_CPU_COUNTER \| MIPS_CPU_WATCH \|
	MIPS_CPU_LLSC;
	c->tlbsize = 64;
	break;
	case PRID_IMP_LOONGSON2:
	c->cputype = CPU_LOONGSON2;
	c->isa_level = MIPS_CPU_ISA_III;
	c->options = R4K_OPTS \|
	MIPS_CPU_FPU \| MIPS_CPU_LLSC \|
	MIPS_CPU_32FPR;
	c->tlbsize = 64;
	break;
	}
	}

	static char unknown_isa[] __initdata = KERN_ERR \
	"Unsupported ISA type, c0.config0: %d.";

	static inline unsigned int decode_config0(struct cpuinfo_mips *c)
	{
	unsigned int config0;
	int isa;

	config0 = read_c0_config();

	if (((config0 & MIPS_CONF_MT) >> 7) == 1)
	c->options \|= MIPS_CPU_TLB;
	isa = (config0 & MIPS_CONF_AT) >> 13;
	switch (isa) {
	case 0:
	switch ((config0 & MIPS_CONF_AR) >> 10) {
	case 0:
	c->isa_level = MIPS_CPU_ISA_M32R1;
	break;
	case 1:
	c->isa_level = MIPS_CPU_ISA_M32R2;
	break;
	default:
	goto unknown;
	}
	break;
	case 2:
	switch ((config0 & MIPS_CONF_AR) >> 10) {
	case 0:
	c->isa_level = MIPS_CPU_ISA_M64R1;
	break;
	case 1:
	c->isa_level = MIPS_CPU_ISA_M64R2;
	break;
	default:
	goto unknown;
	}
	break;
	default:
	goto unknown;
	}

	return config0 & MIPS_CONF_M;

	unknown:
	panic(unknown_isa, config0);
	}

	static inline unsigned int decode_config1(struct cpuinfo_mips *c)
	{
	unsigned int config1;

	config1 = read_c0_config1();

	if (config1 & MIPS_CONF1_MD)
	c->ases \|= MIPS_ASE_MDMX;
	if (config1 & MIPS_CONF1_WR)
	c->options \|= MIPS_CPU_WATCH;
	if (config1 & MIPS_CONF1_CA)
	c->ases \|= MIPS_ASE_MIPS16;
	if (config1 & MIPS_CONF1_EP)
	c->options \|= MIPS_CPU_EJTAG;
	if (config1 & MIPS_CONF1_FP) {
	c->options \|= MIPS_CPU_FPU;
	c->options \|= MIPS_CPU_32FPR;
	}
	if (cpu_has_tlb)
	c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;

	return config1 & MIPS_CONF_M;
	}

	static inline unsigned int decode_config2(struct cpuinfo_mips *c)
	{
	unsigned int config2;

	config2 = read_c0_config2();

	if (config2 & MIPS_CONF2_SL)
	c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;

	return config2 & MIPS_CONF_M;
	}

	static inline unsigned int decode_config3(struct cpuinfo_mips *c)
	{
	unsigned int config3;

	config3 = read_c0_config3();

	if (config3 & MIPS_CONF3_SM)
	c->ases \|= MIPS_ASE_SMARTMIPS;
	if (config3 & MIPS_CONF3_DSP)
	c->ases \|= MIPS_ASE_DSP;
	if (config3 & MIPS_CONF3_VINT)
	c->options \|= MIPS_CPU_VINT;
	if (config3 & MIPS_CONF3_VEIC)
	c->options \|= MIPS_CPU_VEIC;
	if (config3 & MIPS_CONF3_MT)
	c->ases \|= MIPS_ASE_MIPSMT;
	if (config3 & MIPS_CONF3_ULRI)
	c->options \|= MIPS_CPU_ULRI;

	return config3 & MIPS_CONF_M;
	}

	static void __init decode_configs(struct cpuinfo_mips *c)
	{
	/* MIPS32 or MIPS64 compliant CPU. */
	c->options = MIPS_CPU_4KEX \| MIPS_CPU_4K_CACHE \| MIPS_CPU_COUNTER \|
	MIPS_CPU_DIVEC \| MIPS_CPU_LLSC \| MIPS_CPU_MCHECK;

	c->scache.flags = MIPS_CACHE_NOT_PRESENT;

	/* Read Config registers. */
	if (!decode_config0(c))
	return; /* actually worth a panic() */
	if (!decode_config1(c))
	return;
	if (!decode_config2(c))
	return;
	if (!decode_config3(c))
	return;
	}

	static inline void cpu_probe_mips(struct cpuinfo_mips *c)
	{
	decode_configs(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_4KC:
	c->cputype = CPU_4KC;
	break;
	case PRID_IMP_4KEC:
	c->cputype = CPU_4KEC;
	break;
	case PRID_IMP_4KECR2:
	c->cputype = CPU_4KEC;
	break;
	case PRID_IMP_4KSC:
	case PRID_IMP_4KSD:
	c->cputype = CPU_4KSC;
	break;
	case PRID_IMP_5KC:
	c->cputype = CPU_5KC;
	break;
	case PRID_IMP_20KC:
	c->cputype = CPU_20KC;
	break;
	case PRID_IMP_24K:
	case PRID_IMP_24KE:
	c->cputype = CPU_24K;
	break;
	case PRID_IMP_25KF:
	c->cputype = CPU_25KF;
	break;
	case PRID_IMP_34K:
	c->cputype = CPU_34K;
	break;
	case PRID_IMP_74K:
	c->cputype = CPU_74K;
	break;
	}
	}

	static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
	{
	decode_configs(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_AU1_REV1:
	case PRID_IMP_AU1_REV2:
	switch ((c->processor_id >> 24) & 0xff) {
	case 0:
	c->cputype = CPU_AU1000;
	break;
	case 1:
	c->cputype = CPU_AU1500;
	break;
	case 2:
	c->cputype = CPU_AU1100;
	break;
	case 3:
	c->cputype = CPU_AU1550;
	break;
	case 4:
	c->cputype = CPU_AU1200;
	break;
	default:
	panic("Unknown Au Core!");
	break;
	}
	break;
	}
	}

	static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
	{
	decode_configs(c);

	/*
	* For historical reasons the SB1 comes with it's own variant of
	* cache code which eventually will be folded into c-r4k.c. Until
	* then we pretend it's got it's own cache architecture.
	*/
	c->options &= ~MIPS_CPU_4K_CACHE;
	c->options \|= MIPS_CPU_SB1_CACHE;

	switch (c->processor_id & 0xff00) {
	case PRID_IMP_SB1:
	c->cputype = CPU_SB1;
	/* FPU in pass1 is known to have issues. */
	if ((c->processor_id & 0xff) < 0x02)
	c->options &= ~(MIPS_CPU_FPU \| MIPS_CPU_32FPR);
	break;
	case PRID_IMP_SB1A:
	c->cputype = CPU_SB1A;
	break;
	}
	}

	static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
	{
	decode_configs(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_SR71000:
	c->cputype = CPU_SR71000;
	c->scache.ways = 8;
	c->tlbsize = 64;
	break;
	}
	}

	static inline void cpu_probe_philips(struct cpuinfo_mips *c)
	{
	decode_configs(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_PR4450:
	c->cputype = CPU_PR4450;
	c->isa_level = MIPS_CPU_ISA_M32R1;
	break;
	default:
	panic("Unknown Philips Core!"); /* REVISIT: die? */
	break;
	}
	}


	__init void cpu_probe(void)
	{
	struct cpuinfo_mips *c = &current_cpu_data;

	c->processor_id = PRID_IMP_UNKNOWN;
	c->fpu_id = FPIR_IMP_NONE;
	c->cputype = CPU_UNKNOWN;

	c->processor_id = read_c0_prid();
	switch (c->processor_id & 0xff0000) {
	case PRID_COMP_LEGACY:
	cpu_probe_legacy(c);
	break;
	case PRID_COMP_MIPS:
	cpu_probe_mips(c);
	break;
	case PRID_COMP_ALCHEMY:
	cpu_probe_alchemy(c);
	break;
	case PRID_COMP_SIBYTE:
	cpu_probe_sibyte(c);
	break;
	case PRID_COMP_SANDCRAFT:
	cpu_probe_sandcraft(c);
	break;
	case PRID_COMP_PHILIPS:
	cpu_probe_philips(c);
	break;
	default:
	c->cputype = CPU_UNKNOWN;
	}
	if (c->options & MIPS_CPU_FPU) {
	c->fpu_id = cpu_get_fpu_id();

	if (c->isa_level == MIPS_CPU_ISA_M32R1 \|\|
	c->isa_level == MIPS_CPU_ISA_M32R2 \|\|
	c->isa_level == MIPS_CPU_ISA_M64R1 \|\|
	c->isa_level == MIPS_CPU_ISA_M64R2) {
	if (c->fpu_id & MIPS_FPIR_3D)
	c->ases \|= MIPS_ASE_MIPS3D;
	}
	}
	}

	__init void cpu_report(void)
	{
	struct cpuinfo_mips *c = &current_cpu_data;

	printk("CPU revision is: %08x\n", c->processor_id);
	if (c->options & MIPS_CPU_FPU)
	printk("FPU revision is: %08x\n", c->fpu_id);
	}