/*      $NetBSD: ka43.c,v 1.36 2017/05/22 16:46:15 ragge Exp $ */
/*
 * Copyright (c) 1996 Ludd, University of Lule}, Sweden.
 * All rights reserved.
 *
 * This code is derived from software contributed to Ludd by Bertram Barth.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ka43.c,v 1.36 2017/05/22 16:46:15 ragge Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/kernel.h>

#include <machine/sid.h>
#include <machine/nexus.h>
#include <machine/vsbus.h>
#include <machine/ka43.h>
#include <machine/clock.h>

static  void ka43_conf(void);
static  void ka43_steal_pages(void);

static  int ka43_mchk(void *);
static  void ka43_memerr(void);
#if 0
static  void ka43_clear_errors(void);
#endif
static  int ka43_cache_init(void);      /* "int mapen" as argument? */
static  int ka43_cache_reset(void);
static  int ka43_cache_enable(void);
static  int ka43_cache_disable(void);
static  int ka43_cache_invalidate(void);
static  void ka43_halt(void);
static  void ka43_reboot(int);
static  void ka43_clrf(void);

static const char * const ka43_devs[] = { "cpu", "vsbus", NULL };

const struct cpu_dep ka43_calls = {
        .cpu_steal_pages = ka43_steal_pages,
        .cpu_mchk       = ka43_mchk,
        .cpu_memerr     = ka43_memerr,
        .cpu_conf       = ka43_conf,
        .cpu_gettime    = chip_gettime,
        .cpu_settime    = chip_settime,
        .cpu_vups       = 7,    /* 7.6 VUP */
        .cpu_scbsz      = 2,    /* SCB pages */
        .cpu_halt       = ka43_halt,
        .cpu_reboot     = ka43_reboot,
        .cpu_clrf       = ka43_clrf,
        .cpu_devs       = ka43_devs,
        .cpu_flags      = CPU_RAISEIPL,
};

/*
 * ka43_steal_pages() is called with MMU disabled, after that call MMU gets
 * enabled. Thus we initialize these four pointers with physical addresses,
 * but before leving ka43_steal_pages() we reset them to virtual addresses.
 */
static  volatile struct ka43_cpu   *ka43_cpu    = (void*)KA43_CPU_BASE;
static  volatile u_int  *ka43_creg = (void*)KA43_CH2_CREG;
static  volatile u_int  *ka43_ctag = (void*)KA43_CT2_BASE;

#define KA43_MC_RESTART 0x00008000      /* Restart possible*/
#define KA43_PSL_FPDONE 0x00010000      /* First Part Done */

struct ka43_mcframe {           /* Format of RigelMAX machine check frame: */
        int     mc43_bcnt;      /* byte count, always 24 (0x18) */
        int     mc43_code;      /* machine check type code and restart bit */
        int     mc43_addr;      /* most recent (faulting?) virtual address */
        int     mc43_viba;      /* contents of VIBA register */
        int     mc43_sisr;      /* ICCS bit 6 and SISR bits 15:0 */
        int     mc43_istate;    /* internal state */
        int     mc43_sc;        /* shift count register */
        int     mc43_pc;        /* trapped PC */
        int     mc43_psl;       /* trapped PSL */
};

static const char * const ka43_mctype[] = {
        "no error (0)",                 /* Code 0: No error */
        "FPA: protocol error",          /* Code 1-5: FPA errors */
        "FPA: illegal opcode",
        "FPA: operand parity error",
        "FPA: unknown status",
        "FPA: result parity error",
        "unused (6)",                   /* Code 6-7: Unused */
        "unused (7)",
        "MMU error (TLB miss)",         /* Code 8-9: MMU errors */
        "MMU error (TLB hit)",
        "HW interrupt at unused IPL",   /* Code 10: Interrupt error */
        "MOVCx impossible state",       /* Code 11-13: Microcode errors */
        "undefined trap code (i-box)",
        "undefined control store address",
        "unused (14)",                  /* Code 14-15: Unused */
        "unused (15)",
        "PC tag or data parity error",  /* Code 16: Cache error */
        "data bus parity error",        /* Code 17: Read error */
        "data bus error (NXM)",         /* Code 18: Write error */
        "undefined data bus state",     /* Code 19: Bus error */
};
#define MC43_MAX        19

static int ka43_error_count = 0;

int
ka43_mchk(void *addr)
{
        struct ka43_mcframe *mcf = (void*)addr;

        mtpr(0x00, PR_MCESR);   /* Acknowledge the machine check */
        printf("machine check %d (0x%x)\n", mcf->mc43_code, mcf->mc43_code);
        printf("reason: %s\n", ka43_mctype[mcf->mc43_code & 0xff]);
        if (++ka43_error_count > 10) {
                printf("error_count exceeded: %d\n", ka43_error_count);
                return (-1);
        }

        /*
         * If either the Restart flag is set or the First-Part-Done flag
         * is set, and the TRAP2 (double error) bit is not set, then the
         * error is recoverable.
         */
        if (mfpr(PR_PCSTS) & KA43_PCS_TRAP2) {
                printf("TRAP2 (double error) in ka43_mchk.\n");
                panic("unrecoverable state in ka43_mchk.");
                return (-1);
        }
        if ((mcf->mc43_code & KA43_MC_RESTART) || 
            (mcf->mc43_psl & KA43_PSL_FPDONE)) {
                printf("ka43_mchk: recovering from machine-check.\n");
                ka43_cache_reset();     /* reset caches */
                return (0);             /* go on; */
        }

        /*
         * Unknown error state, panic/halt the machine!
         */
        printf("ka43_mchk: unknown error state!\n");
        return (-1);
}

void
ka43_memerr(void)
{
        char sbuf[256];

        /*
         * Don\'t know what to do here. So just print some messages
         * and try to go on...
         */

        printf("memory error!\n");

        snprintb(sbuf, sizeof(sbuf), KA43_PCSTS_BITS, mfpr(PR_PCSTS));
        printf("primary cache status: %s\n", sbuf);

        snprintb(sbuf, sizeof(sbuf), KA43_SESR_BITS, *ka43_creg);
        printf("secondary cache status: %s\n", sbuf);
}

int
ka43_cache_init(void)
{
        return (ka43_cache_reset());
}

#if 0
void
ka43_clear_errors(void)
{
        int val = *ka43_creg;
        val |= KA43_SESR_SERR | KA43_SESR_LERR | KA43_SESR_CERR;
        *ka43_creg = val;
}
#endif

int
ka43_cache_reset(void)
{
        char sbuf[256];

        /*
         * resetting primary and secondary caches is done in three steps:
         *      1. disable both caches
         *      2. manually clear secondary cache
         *      3. enable both caches
         */
        ka43_cache_disable();
        ka43_cache_invalidate();
        ka43_cache_enable();

        snprintb(sbuf, sizeof(sbuf), KA43_PCSTS_BITS, mfpr(PR_PCSTS));
        printf("primary cache status: %s\n", sbuf);

        snprintb(sbuf, sizeof(sbuf), KA43_SESR_BITS, *ka43_creg);
        printf("secondary cache status: %s\n", sbuf);

        return (0);
}

int
ka43_cache_disable(void)
{
        int val;

        /*
         * first disable primary cache and clear error flags
         */
        mtpr(KA43_PCS_REFRESH, PR_PCSTS);       /* disable primary cache */
        val = mfpr(PR_PCSTS);
        mtpr(val, PR_PCSTS);                    /* clear error flags */

        /*
         * now disable secondary cache and clear error flags
         */
        val = *ka43_creg & ~KA43_SESR_CENB;     /* BICL !!! */
        *ka43_creg = val;                       /* disable secondary cache */
        val = KA43_SESR_SERR | KA43_SESR_LERR | KA43_SESR_CERR;
        *ka43_creg = val;                       /* clear error flags */

        return (0);
}

int
ka43_cache_invalidate(void)
{
        int i, val;

        val = KA43_PCTAG_PARITY;        /* clear valid flag, set parity bit */
        for (i = 0; i < 256; i++) {     /* 256 Quadword entries */
                mtpr(i*8, PR_PCIDX);    /* write index of tag */
                mtpr(val, PR_PCTAG);    /* write value into tag */
        }
        val = KA43_PCS_FLUSH | KA43_PCS_REFRESH;
        mtpr(val, PR_PCSTS);            /* flush primary cache */

        /*
         * Rigel\'s secondary cache doesn\'t implement a valid-flag.
         * Thus we initialize all entries with out-of-range/dummy
         * addresses which will never be referenced (ie. never hit).
         * After enabling cache we also access 128K of memory starting
         * at 0x00 so that secondary cache will be filled with these
         * valid addresses...
         */
        val = 0xff;
        /* if (memory > 28 MB) val = 0x55; */
        for (i = 0; i < KA43_CT2_SIZE; i+= 4) { /* Quadword entries ?? */
                ka43_ctag[i/4] = val;           /* reset upper and lower */
        }

        return (0);
}


int
ka43_cache_enable(void)
{
        volatile char *membase = (void*)0x80000000;     /* physical 0x00 */
        int i, val;

        val = KA43_PCS_FLUSH | KA43_PCS_REFRESH;
        mtpr(val, PR_PCSTS);            /* flush primary cache */

        /*
         * now we enable secondary cache and access first 128K of memory
         * so that secondary cache gets really initialized and holds
         * valid addresses/data...
         */
        *ka43_creg = KA43_SESR_CENB;    /* enable secondary cache */
        for (i=0; i<128*1024; i++) {
                val += membase[i];      /* some dummy operation... */
        }

        val = KA43_PCS_ENABLE | KA43_PCS_REFRESH;
        mtpr(val, PR_PCSTS);            /* enable primary cache */

        return (0);
}

void
ka43_conf(void)
{
        curcpu()->ci_cpustr = "Rigel, 2KB L1 cache, 128KB L2 cache";

        ka43_cpu = (void *)vax_map_physmem(VS_REGS, 1);
        ka43_creg = (void *)vax_map_physmem(KA43_CH2_CREG, 1);
        ka43_ctag = (void *)vax_map_physmem(KA43_CT2_BASE,
            (KA43_CT2_SIZE/VAX_NBPG));

        /*
         * ka43_conf() gets called with MMU enabled, now it's save to
         * init/reset the caches.
         */
        ka43_cache_init();

        clk_adrshift = 1;       /* Addressed at long's... */
        clk_tweak = 2;          /* ...and shift two */
        clk_page = (short *)vax_map_physmem(VS_CLOCK, 1);
}


/*
 * The interface for communication with the LANCE ethernet controller
 * is setup in the xxx_steal_pages() routine. We decrease highest
 * available address by 64K and use this area as communication buffer.
 */

void
ka43_steal_pages(void)
{
        int     val;


        /*
         * if LANCE\'s io-buffer is above 16 MB, then the appropriate flag
         * in the parity control register has to be set (it works as an
         * additional address bit). In any case, don\'t enable CPEN and
         * DPEN in the PARCTL register, somewhow they are internally managed
         * by the RIGEL chip itself!?!
         */
        val = ka43_cpu->parctl & 0x03;  /* read the old value */
        ka43_cpu->parctl = val;         /* and write new value */
}

void
ka43_clrf(void)
{
        volatile struct ka43_clock *clk = (volatile void *)clk_page;

        /*
         * Clear restart and boot in progress flags in the CPMBX.
         * The cpmbx is split into two 4-bit fields.
         * One for the current restart/boot in progress flags, and
         * one for the permanent halt flag.
         * The restart/boot in progress flag is also used as the action request
         * for the CPU at a halt. /BQT
         */
        clk->req = 0;
}

void
ka43_halt(void)
{
        volatile struct ka43_clock *clk = (volatile void *)clk_page;
        clk->req = 3;           /* 3 is halt. */
        __asm("halt");
}

void
ka43_reboot(int arg)
{
        volatile struct ka43_clock *clk = (volatile void *)clk_page;
        clk->req = 2;           /* 2 is reboot. */
        __asm("halt");
}