/*
 * 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>
#include <asm/watch.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();
}

extern void r4k_wait(void);

/*
 * 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.
 */
void r4k_wait_irqoff(void)
{
        local_irq_disable();
        if (!need_resched())
                __asm__("       .set    push            \n"
                        "       .set    mips3           \n"
                        "       wait                    \n"
                        "       .set    pop             \n");
        local_irq_enable();
        __asm__("       .globl __pastwait       \n"
                "__pastwait:                    \n");
        return;
}

/*
 * The RM7000 variant has to handle erratum 38.  The workaround is to not
 * have any pending stores when the WAIT instruction is executed.
 */
static void rm7k_wait_irqoff(void)
{
        local_irq_disable();
        if (!need_resched())
                __asm__(
                "       .set    push                                    \n"
                "       .set    mips3                                   \n"
                "       .set    noat                                    \n"
                "       mfc0    $1, $12                                 \n"
                "       sync                                            \n"
                "       mtc0    $1, $12         # stalls until W stage  \n"
                "       wait                                            \n"
                "       mtc0    $1, $12         # stalls until W stage  \n"
                "       .set    pop                                     \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)
{
        if (!allow_au1k_wait)
                return;

        /* 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);

void __init 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_R5500:
        case CPU_NEVADA:
        case CPU_4KC:
        case CPU_4KEC:
        case CPU_4KSC:
        case CPU_5KC:
        case CPU_25KF:
        case CPU_PR4450:
        case CPU_BCM3302:
        case CPU_CAVIUM_OCTEON:
                cpu_wait = r4k_wait;
                break;

        case CPU_RM7000:
                cpu_wait = rm7k_wait_irqoff;
                break;

        case CPU_24K:
        case CPU_34K:
        case CPU_1004K:
                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_ALCHEMY:
                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;

                /*
                 * Another rev is incremeting c0_count at a reduced clock
                 * rate while in WAIT mode.  So we basically have the choice
                 * between using the cp0 timer as clocksource or avoiding
                 * the WAIT instruction.  Until more details are known,
                 * disable the use of WAIT for 20Kc entirely.
                   cpu_wait = r4k_wait;
                 */
                break;
        case CPU_RM9000:
                if ((c->processor_id & 0x00ff) >= 0x40)
                        cpu_wait = r4k_wait;
                break;
        default:
                break;
        }
}

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

        switch (c->cputype) {
        case CPU_34K:
                /*
                 * Erratum "RPS May Cause Incorrect Instruction Execution"
                 * This code only handles VPE0, any SMP/SMTC/RTOS code
                 * making use of VPE1 will be responsable for that VPE.
                 */
                if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
                        write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
                break;
        default:
                break;
        }
}

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

/*
 * 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, unsigned int cpu)
{
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_R2000:
                c->cputype = CPU_R2000;
                __cpu_name[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;
                                __cpu_name[cpu] = "R3081";
                        } else {
                                c->cputype = CPU_R3000A;
                                __cpu_name[cpu] = "R3000A";
                        }
                        break;
                } else {
                        c->cputype = CPU_R3000;
                        __cpu_name[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;
                                __cpu_name[cpu] = "R4400PC";
                        } else {
                                c->cputype = CPU_R4000PC;
                                __cpu_name[cpu] = "R4000PC";
                        }
                } else {
                        if ((c->processor_id & 0xff) >= PRID_REV_R4400) {
                                c->cputype = CPU_R4400SC;
                                __cpu_name[cpu] = "R4400SC";
                        } else {
                                c->cputype = CPU_R4000SC;
                                __cpu_name[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;
                        __cpu_name[cpu] = "NEC VR4111";
                        break;
                case PRID_REV_VR4121:
                        c->cputype = CPU_VR4121;
                        __cpu_name[cpu] = "NEC VR4121";
                        break;
                case PRID_REV_VR4122:
                        if ((c->processor_id & 0xf) < 0x3) {
                                c->cputype = CPU_VR4122;
                                __cpu_name[cpu] = "NEC VR4122";
                        } else {
                                c->cputype = CPU_VR4181A;
                                __cpu_name[cpu] = "NEC VR4181A";
                        }
                        break;
                case PRID_REV_VR4130:
                        if ((c->processor_id & 0xf) < 0x4) {
                                c->cputype = CPU_VR4131;
                                __cpu_name[cpu] = "NEC VR4131";
                        } else {
                                c->cputype = CPU_VR4133;
                                __cpu_name[cpu] = "NEC VR4133";
                        }
                        break;
                default:
                        printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
                        c->cputype = CPU_VR41XX;
                        __cpu_name[cpu] = "NEC 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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                        __cpu_name[cpu] = "TX3927";
                        c->tlbsize = 64;
                } else {
                        switch (c->processor_id & 0xff) {
                        case PRID_REV_TX3912:
                                c->cputype = CPU_TX3912;
                                __cpu_name[cpu] = "TX3912";
                                c->tlbsize = 32;
                                break;
                        case PRID_REV_TX3922:
                                c->cputype = CPU_TX3922;
                                __cpu_name[cpu] = "TX3922";
                                c->tlbsize = 64;
                                break;
                        }
                }
                break;
        case PRID_IMP_R4700:
                c->cputype = CPU_R4700;
                __cpu_name[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;
                __cpu_name[cpu] = "R49XX";
                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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[cpu] = "RM8000";
                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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[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;
                __cpu_name[cpu] = "ICT Loongson-2";
                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[] __cpuinitdata = 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 __cpuinit decode_configs(struct cpuinfo_mips *c)
{
        int ok;

        /* 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;

        ok = decode_config0(c);                 /* Read Config registers.  */
        BUG_ON(!ok);                            /* Arch spec violation!  */
        if (ok)
                ok = decode_config1(c);
        if (ok)
                ok = decode_config2(c);
        if (ok)
                ok = decode_config3(c);

        mips_probe_watch_registers(c);
}

#ifdef CONFIG_CPU_MIPSR2
extern void spram_config(void);
#else
static inline void spram_config(void) {}
#endif

static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_4KC:
                c->cputype = CPU_4KC;
                __cpu_name[cpu] = "MIPS 4Kc";
                break;
        case PRID_IMP_4KEC:
                c->cputype = CPU_4KEC;
                __cpu_name[cpu] = "MIPS 4KEc";
                break;
        case PRID_IMP_4KECR2:
                c->cputype = CPU_4KEC;
                __cpu_name[cpu] = "MIPS 4KEc";
                break;
        case PRID_IMP_4KSC:
        case PRID_IMP_4KSD:
                c->cputype = CPU_4KSC;
                __cpu_name[cpu] = "MIPS 4KSc";
                break;
        case PRID_IMP_5KC:
                c->cputype = CPU_5KC;
                __cpu_name[cpu] = "MIPS 5Kc";
                break;
        case PRID_IMP_20KC:
                c->cputype = CPU_20KC;
                __cpu_name[cpu] = "MIPS 20Kc";
                break;
        case PRID_IMP_24K:
        case PRID_IMP_24KE:
                c->cputype = CPU_24K;
                __cpu_name[cpu] = "MIPS 24Kc";
                break;
        case PRID_IMP_25KF:
                c->cputype = CPU_25KF;
                __cpu_name[cpu] = "MIPS 25Kc";
                break;
        case PRID_IMP_34K:
                c->cputype = CPU_34K;
                __cpu_name[cpu] = "MIPS 34Kc";
                break;
        case PRID_IMP_74K:
                c->cputype = CPU_74K;
                __cpu_name[cpu] = "MIPS 74Kc";
                break;
        case PRID_IMP_1004K:
                c->cputype = CPU_1004K;
                __cpu_name[cpu] = "MIPS 1004Kc";
                break;
        }

        spram_config();
}

static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_AU1_REV1:
        case PRID_IMP_AU1_REV2:
                c->cputype = CPU_ALCHEMY;
                switch ((c->processor_id >> 24) & 0xff) {
                case 0:
                        __cpu_name[cpu] = "Au1000";
                        break;
                case 1:
                        __cpu_name[cpu] = "Au1500";
                        break;
                case 2:
                        __cpu_name[cpu] = "Au1100";
                        break;
                case 3:
                        __cpu_name[cpu] = "Au1550";
                        break;
                case 4:
                        __cpu_name[cpu] = "Au1200";
                        if ((c->processor_id & 0xff) == 2)
                                __cpu_name[cpu] = "Au1250";
                        break;
                case 5:
                        __cpu_name[cpu] = "Au1210";
                        break;
                default:
                        __cpu_name[cpu] = "Au1xxx";
                        break;
                }
                break;
        }
}

static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);

        switch (c->processor_id & 0xff00) {
        case PRID_IMP_SB1:
                c->cputype = CPU_SB1;
                __cpu_name[cpu] = "SiByte 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;
                __cpu_name[cpu] = "SiByte SB1A";
                break;
        }
}

static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_SR71000:
                c->cputype = CPU_SR71000;
                __cpu_name[cpu] = "Sandcraft SR71000";
                c->scache.ways = 8;
                c->tlbsize = 64;
                break;
        }
}

static inline void cpu_probe_nxp(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_PR4450:
                c->cputype = CPU_PR4450;
                __cpu_name[cpu] = "Philips PR4450";
                c->isa_level = MIPS_CPU_ISA_M32R1;
                break;
        }
}

static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_BCM3302:
                c->cputype = CPU_BCM3302;
                __cpu_name[cpu] = "Broadcom BCM3302";
                break;
        case PRID_IMP_BCM4710:
                c->cputype = CPU_BCM4710;
                __cpu_name[cpu] = "Broadcom BCM4710";
                break;
        }
}

static inline void cpu_probe_cavium(struct cpuinfo_mips *c, unsigned int cpu)
{
        decode_configs(c);
        switch (c->processor_id & 0xff00) {
        case PRID_IMP_CAVIUM_CN38XX:
        case PRID_IMP_CAVIUM_CN31XX:
        case PRID_IMP_CAVIUM_CN30XX:
        case PRID_IMP_CAVIUM_CN58XX:
        case PRID_IMP_CAVIUM_CN56XX:
        case PRID_IMP_CAVIUM_CN50XX:
        case PRID_IMP_CAVIUM_CN52XX:
                c->cputype = CPU_CAVIUM_OCTEON;
                __cpu_name[cpu] = "Cavium Octeon";
                break;
        default:
                printk(KERN_INFO "Unknown Octeon chip!\n");
                c->cputype = CPU_UNKNOWN;
                break;
        }
}

const char *__cpu_name[NR_CPUS];

__cpuinit void cpu_probe(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int cpu = smp_processor_id();

        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, cpu);
                break;
        case PRID_COMP_MIPS:
                cpu_probe_mips(c, cpu);
                break;
        case PRID_COMP_ALCHEMY:
                cpu_probe_alchemy(c, cpu);
                break;
        case PRID_COMP_SIBYTE:
                cpu_probe_sibyte(c, cpu);
                break;
        case PRID_COMP_BROADCOM:
                cpu_probe_broadcom(c, cpu);
                break;
        case PRID_COMP_SANDCRAFT:
                cpu_probe_sandcraft(c, cpu);
                break;
        case PRID_COMP_NXP:
                cpu_probe_nxp(c, cpu);
                break;
        case PRID_COMP_CAVIUM:
                cpu_probe_cavium(c, cpu);
                break;
        }

        BUG_ON(!__cpu_name[cpu]);
        BUG_ON(c->cputype == CPU_UNKNOWN);

        /*
         * Platform code can force the cpu type to optimize code
         * generation. In that case be sure the cpu type is correctly
         * manually setup otherwise it could trigger some nasty bugs.
         */
        BUG_ON(current_cpu_type() != c->cputype);

        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;
                }
        }

        if (cpu_has_mips_r2)
                c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
        else
                c->srsets = 1;
}

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

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