mips-mt.c

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/*
 * General MIPS MT support routines, usable in AP/SP, SMVP, or SMTC kernels
 * Copyright (C) 2005 Mips Technologies, Inc
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/security.h>

#include <asm/cpu.h>
#include <asm/processor.h>
#include <linux/atomic.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
#include <asm/mipsmtregs.h>
#include <asm/r4kcache.h>
#include <asm/cacheflush.h>

int vpelimit;

static int __init maxvpes(char *str)
{
    get_option(&str, &vpelimit);

    return 1;
}

__setup("maxvpes=", maxvpes);

int tclimit;

static int __init maxtcs(char *str)
{
    get_option(&str, &tclimit);

    return 1;
}

__setup("maxtcs=", maxtcs);

/*
 * Dump new MIPS MT state for the core. Does not leave TCs halted.
 * Takes an argument which taken to be a pre-call MVPControl value.
 */

void mips_mt_regdump(unsigned long mvpctl)
{
    unsigned long flags;
    unsigned long vpflags;
    unsigned long mvpconf0;
    int nvpe;
    int ntc;
    int i;
    int tc;
    unsigned long haltval;
    unsigned long tcstatval;
#ifdef CONFIG_MIPS_MT_SMTC
    void smtc_soft_dump(void);
#endif /* CONFIG_MIPT_MT_SMTC */

    local_irq_save(flags);
    vpflags = dvpe();
    printk("=== MIPS MT State Dump ===\n");
    printk("-- Global State --\n");
    printk("   MVPControl Passed: %08lx\n", mvpctl);
    printk("   MVPControl Read: %08lx\n", vpflags);
    printk("   MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0()));
    nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
    ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
    printk("-- per-VPE State --\n");
    for (i = 0; i < nvpe; i++) {
        for (tc = 0; tc < ntc; tc++) {
            settc(tc);
            if ((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) {
                printk("  VPE %d\n", i);
                printk("   VPEControl : %08lx\n",
                       read_vpe_c0_vpecontrol());
                printk("   VPEConf0 : %08lx\n",
                       read_vpe_c0_vpeconf0());
                printk("   VPE%d.Status : %08lx\n",
                       i, read_vpe_c0_status());
                printk("   VPE%d.EPC : %08lx %pS\n",
                       i, read_vpe_c0_epc(),
                       (void *) read_vpe_c0_epc());
                printk("   VPE%d.Cause : %08lx\n",
                       i, read_vpe_c0_cause());
                printk("   VPE%d.Config7 : %08lx\n",
                       i, read_vpe_c0_config7());
                break; /* Next VPE */
            }
        }
    }
    printk("-- per-TC State --\n");
    for (tc = 0; tc < ntc; tc++) {
        settc(tc);
        if (read_tc_c0_tcbind() == read_c0_tcbind()) {
            /* Are we dumping ourself?  */
            haltval = 0; /* Then we're not halted, and mustn't be */
            tcstatval = flags; /* And pre-dump TCStatus is flags */
            printk("  TC %d (current TC with VPE EPC above)\n", tc);
        } else {
            haltval = read_tc_c0_tchalt();
            write_tc_c0_tchalt(1);
            tcstatval = read_tc_c0_tcstatus();
            printk("  TC %d\n", tc);
        }
        printk("   TCStatus : %08lx\n", tcstatval);
        printk("   TCBind : %08lx\n", read_tc_c0_tcbind());
        printk("   TCRestart : %08lx %pS\n",
               read_tc_c0_tcrestart(), (void *) read_tc_c0_tcrestart());
        printk("   TCHalt : %08lx\n", haltval);
        printk("   TCContext : %08lx\n", read_tc_c0_tccontext());
        if (!haltval)
            write_tc_c0_tchalt(0);
    }
#ifdef CONFIG_MIPS_MT_SMTC
    smtc_soft_dump();
#endif /* CONFIG_MIPT_MT_SMTC */
    printk("===========================\n");
    evpe(vpflags);
    local_irq_restore(flags);
}

static int mt_opt_norps;
static int mt_opt_rpsctl = -1;
static int mt_opt_nblsu = -1;
static int mt_opt_forceconfig7;
static int mt_opt_config7 = -1;

static int __init rps_disable(char *s)
{
    mt_opt_norps = 1;
    return 1;
}
__setup("norps", rps_disable);

static int __init rpsctl_set(char *str)
{
    get_option(&str, &mt_opt_rpsctl);
    return 1;
}
__setup("rpsctl=", rpsctl_set);

static int __init nblsu_set(char *str)
{
    get_option(&str, &mt_opt_nblsu);
    return 1;
}
__setup("nblsu=", nblsu_set);

static int __init config7_set(char *str)
{
    get_option(&str, &mt_opt_config7);
    mt_opt_forceconfig7 = 1;
    return 1;
}
__setup("config7=", config7_set);

/* Experimental cache flush control parameters that should go away some day */
int mt_protiflush;
int mt_protdflush;
int mt_n_iflushes = 1;
int mt_n_dflushes = 1;

static int __init set_protiflush(char *s)
{
    mt_protiflush = 1;
    return 1;
}
__setup("protiflush", set_protiflush);

static int __init set_protdflush(char *s)
{
    mt_protdflush = 1;
    return 1;
}
__setup("protdflush", set_protdflush);

static int __init niflush(char *s)
{
    get_option(&s, &mt_n_iflushes);
    return 1;
}
__setup("niflush=", niflush);

static int __init ndflush(char *s)
{
    get_option(&s, &mt_n_dflushes);
    return 1;
}
__setup("ndflush=", ndflush);

static unsigned int itc_base;

static int __init set_itc_base(char *str)
{
    get_option(&str, &itc_base);
    return 1;
}

__setup("itcbase=", set_itc_base);

void mips_mt_set_cpuoptions(void)
{
    unsigned int oconfig7 = read_c0_config7();
    unsigned int nconfig7 = oconfig7;

    if (mt_opt_norps) {
        printk("\"norps\" option deprecated: use \"rpsctl=\"\n");
    }
    if (mt_opt_rpsctl >= 0) {
        printk("34K return prediction stack override set to %d.\n",
            mt_opt_rpsctl);
        if (mt_opt_rpsctl)
            nconfig7 |= (1 << 2);
        else
            nconfig7 &= ~(1 << 2);
    }
    if (mt_opt_nblsu >= 0) {
        printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
        if (mt_opt_nblsu)
            nconfig7 |= (1 << 5);
        else
            nconfig7 &= ~(1 << 5);
    }
    if (mt_opt_forceconfig7) {
        printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
        nconfig7 = mt_opt_config7;
    }
    if (oconfig7 != nconfig7) {
        __asm__ __volatile("sync");
        write_c0_config7(nconfig7);
        ehb();
        printk("Config7: 0x%08x\n", read_c0_config7());
    }

    /* Report Cache management debug options */
    if (mt_protiflush)
        printk("I-cache flushes single-threaded\n");
    if (mt_protdflush)
        printk("D-cache flushes single-threaded\n");
    if (mt_n_iflushes != 1)
        printk("I-Cache Flushes Repeated %d times\n", mt_n_iflushes);
    if (mt_n_dflushes != 1)
        printk("D-Cache Flushes Repeated %d times\n", mt_n_dflushes);

    if (itc_base != 0) {
        /*
         * Configure ITC mapping.  This code is very
         * specific to the 34K core family, which uses
         * a special mode bit ("ITC") in the ErrCtl
         * register to enable access to ITC control
         * registers via cache "tag" operations.
         */
        unsigned long ectlval;
        unsigned long itcblkgrn;

        /* ErrCtl register is known as "ecc" to Linux */
        ectlval = read_c0_ecc();
        write_c0_ecc(ectlval | (0x1 << 26));
        ehb();
#define INDEX_0 (0x80000000)
#define INDEX_8 (0x80000008)
        /* Read "cache tag" for Dcache pseudo-index 8 */
        cache_op(Index_Load_Tag_D, INDEX_8);
        ehb();
        itcblkgrn = read_c0_dtaglo();
        itcblkgrn &= 0xfffe0000;
        /* Set for 128 byte pitch of ITC cells */
        itcblkgrn |= 0x00000c00;
        /* Stage in Tag register */
        write_c0_dtaglo(itcblkgrn);
        ehb();
        /* Write out to ITU with CACHE op */
        cache_op(Index_Store_Tag_D, INDEX_8);
        /* Now set base address, and turn ITC on with 0x1 bit */
        write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
        ehb();
        /* Write out to ITU with CACHE op */
        cache_op(Index_Store_Tag_D, INDEX_0);
        write_c0_ecc(ectlval);
        ehb();
        printk("Mapped %ld ITC cells starting at 0x%08x\n",
            ((itcblkgrn & 0x7fe00000) >> 20), itc_base);
    }
}

/*
 * Function to protect cache flushes from concurrent execution
 * depends on MP software model chosen.
 */

void mt_cflush_lockdown(void)
{
#ifdef CONFIG_MIPS_MT_SMTC
    void smtc_cflush_lockdown(void);

    smtc_cflush_lockdown();
#endif /* CONFIG_MIPS_MT_SMTC */
    /* FILL IN VSMP and AP/SP VERSIONS HERE */
}

void mt_cflush_release(void)
{
#ifdef CONFIG_MIPS_MT_SMTC
    void smtc_cflush_release(void);

    smtc_cflush_release();
#endif /* CONFIG_MIPS_MT_SMTC */
    /* FILL IN VSMP and AP/SP VERSIONS HERE */
}

struct class *mt_class;

static int __init mt_init(void)
{
    struct class *mtc;

    mtc = class_create(THIS_MODULE, "mt");
    if (IS_ERR(mtc))
        return PTR_ERR(mtc);

    mt_class = mtc;

    return 0;
}

subsys_initcall(mt_init);