/*      $NetBSD: kgdb_machdep.c,v 1.26 2024/09/08 10:02:49 andvar Exp $ */

/*
 * Copyright 2001 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Allen Briggs for Wasabi Systems, Inc.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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: kgdb_machdep.c,v 1.26 2024/09/08 10:02:49 andvar Exp $");

#ifdef _KERNEL_OPT
#include "opt_ppcarch.h"
#endif

/*
 * Machine-dependent functions for remote KGDB.
 */

#include <sys/param.h>
#include <sys/kgdb.h>
#include <sys/systm.h>

#include <uvm/uvm_extern.h>

#include <machine/reg.h>
#include <machine/trap.h>
#include <machine/pmap.h>
#include <machine/psl.h>

#include <powerpc/spr.h>
#if defined (PPC_OEA) || defined (PPC_OEA601) || defined (PPC_OEA64_BRIDGE)
#include <powerpc/oea/spr.h>
#include <powerpc/oea/bat.h>

#elif defined (PPC_OEA64)
#include <powerpc/oea/spr.h>

#elif defined (PPC_IBM4XX)
#include <powerpc/booke/spr.h>

#elif defined (PPC_BOOKE)
#include <powerpc/booke/spr.h>

#else
#error unknown architecture
#endif

/*
 * Determine if the memory at va..(va+len) is valid.
 */
int
kgdb_acc(vaddr_t va, size_t len)
{
        vaddr_t   last_va;
        paddr_t   pa;
        u_int msr;
#if defined (PPC_OEA) || defined (PPC_OEA601) || defined (PPC_OEA64_BRIDGE)
        u_int batu;
#ifdef PPC_OEA601
        u_int batl;
#endif
#endif

        /* If translation is off, everything is fair game */
        __asm volatile ("mfmsr %0" : "=r"(msr));
        if ((msr & PSL_DR) == 0) {
                return 1;
        }

#if defined (PPC_OEA) || defined (PPC_OEA601) || defined (PPC_OEA64_BRIDGE)
        /* Now check battable registers */
#ifdef PPC_OEA601
        if ((mfpvr() >> 16) == MPC601) {
                __asm volatile ("mfibatl %0,0" : "=r"(batl));
                __asm volatile ("mfibatu %0,0" : "=r"(batu));
                if (BAT601_VALID_P(batl) &&
                                BAT601_VA_MATCH_P(batu,batl,va))
                        return 1;
                __asm volatile ("mfibatl %0,1" : "=r"(batl));
                __asm volatile ("mfibatu %0,1" : "=r"(batu));
                if (BAT601_VALID_P(batl) &&
                                BAT601_VA_MATCH_P(batu,batl,va))
                        return 1;
                __asm volatile ("mfibatl %0,2" : "=r"(batl));
                __asm volatile ("mfibatu %0,2" : "=r"(batu));
                if (BAT601_VALID_P(batl) &&
                                BAT601_VA_MATCH_P(batu,batl,va))
                        return 1;
                __asm volatile ("mfibatl %0,3" : "=r"(batl));
                __asm volatile ("mfibatu %0,3" : "=r"(batu));
                if (BAT601_VALID_P(batl) &&
                                BAT601_VA_MATCH_P(batu,batl,va))
                        return 1;
        } else {
#endif /* PPC_OEA601 */
                __asm volatile ("mfdbatu %0,0" : "=r"(batu));
                if (BAT_VALID_P(batu,msr) &&
                                BAT_VA_MATCH_P(batu,va) &&
                                (batu & BAT_PP) != BAT_PP_NONE) {
                        return 1;
                }
                __asm volatile ("mfdbatu %0,1" : "=r"(batu));
                if (BAT_VALID_P(batu,msr) &&
                                BAT_VA_MATCH_P(batu,va) &&
                                (batu & BAT_PP) != BAT_PP_NONE) {
                        return 1;
                }
                __asm volatile ("mfdbatu %0,2" : "=r"(batu));
                if (BAT_VALID_P(batu,msr) &&
                                BAT_VA_MATCH_P(batu,va) &&
                                (batu & BAT_PP) != BAT_PP_NONE) {
                        return 1;
                }
                __asm volatile ("mfdbatu %0,3" : "=r"(batu));
                if (BAT_VALID_P(batu,msr) &&
                                BAT_VA_MATCH_P(batu,va) &&
                                (batu & BAT_PP) != BAT_PP_NONE) {
                        return 1;
#ifdef PPC_OEA601
                }
#endif
        }
#endif /* PPC_OEA || PPC_OEA601 || PPC_OEA64_BRIDGE */

#if defined(PPC_IBM4XX)
        /* Is it (supposed to be) TLB-reserved mapping? */
        if (va < VM_MIN_KERNEL_ADDRESS || va > VM_MAX_KERNEL_ADDRESS)
                return (1);
#endif

        last_va = va + len;
        va  &= ~PGOFSET;
        last_va &= ~PGOFSET;

        do {
                /*
                 * I think this should be able to handle
                 * non-pmap_kernel() va's, too.
                 */
                if (!pmap_extract(pmap_kernel(), va, &pa))
                        return 0;
                va += PAGE_SIZE;
        } while (va <= last_va);

        return (1);
}

/*
 * Translate a trap number into a unix compatible signal value.
 * (gdb only understands unix signal numbers).  Some of these are bogus
 * and should be reviewed.
 */
int 
kgdb_signal(int type)
{
        switch (type) {
#if defined (PPC_IBM4XX) || defined (PPC_BOOKE)
        case EXC_PIT:           /* 40x - Programmable interval timer */
        case EXC_FIT:           /* 40x - Fixed interval timer */
                return SIGALRM;

        case EXC_CII:           /* 40x - Critical input interrupt */
        case EXC_WDOG:          /* 40x - Watchdog timer */
        case EXC_DEBUG:         /* 40x - Debug trap */
                return SIGTRAP;

        case EXC_DTMISS:        /* 40x - Instruction TLB miss */
        case EXC_ITMISS:        /* 40x - Data TLB miss */
                return SIGSEGV;
#endif

#if defined (PPC_OEA) || defined (PPC_OEA601) || defined (PPC_OEA64_BRIDGE)
        case EXC_PERF:          /* 604/750/7400 - Performance monitoring */
        case EXC_BPT:           /* 604/750/7400 - Instruction breakpoint */
        case EXC_SMI:           /* 604/750/7400 - System management interrupt */
        case EXC_THRM:          /* 750/7400 - Thermal management interrupt */
                return SIGTRAP;

        case EXC_IMISS:         /* 603 - Instruction translation miss */
        case EXC_DLMISS:        /* 603 - Data load translation miss */
        case EXC_DSMISS:        /* 603 - Data store translation miss */
                return SIGSEGV;

        case EXC_RST:           /* All but IBM 4xx - Reset */
                return SIGURG;

        case EXC_VEC:           /* 7400 - Altivec unavailable */
        case EXC_VECAST:        /* 7400 - Altivec assist */
                return SIGFPE;
#endif

        case EXC_DECR:          /* Decrementer interrupt */
                return SIGALRM;

        case EXC_EXI:           /* External interrupt */
                return SIGINT;

        case EXC_PGM:           /* Program interrupt */
        case EXC_ALI:           /* Alignment */
                return SIGILL;

  case T_BREAKPOINT:
        case EXC_MCHK:          /* Machine check */
        case EXC_TRC:           /* Trace */
                return SIGTRAP;

        case EXC_ISI:           /* Instruction storage interrupt */
        case EXC_DSI:           /* Data storage interrupt */
                return SIGSEGV;

        case EXC_FPU:           /* Floating point unavailable */
        case EXC_FPA:           /* Floating-point assist */
                return SIGFPE;

        case EXC_SC:            /* System call */
                return SIGURG;

        case EXC_RSVD:          /* Reserved */
        case EXC_AST:           /* Floating point unavailable */
        default:
                return SIGEMT;
        }
}

/*
 * Translate the values stored in the kernel regs struct to the format
 * understood by gdb.
 */
void
kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
{
        memcpy(gdb_regs, regs, 32 * sizeof(unsigned long));
        gdb_regs[KGDB_PPC_PC_REG]  = regs->iar;
        gdb_regs[KGDB_PPC_MSR_REG] = regs->msr;
        gdb_regs[KGDB_PPC_CR_REG]  = regs->cr;
        gdb_regs[KGDB_PPC_LR_REG]  = regs->lr;
        gdb_regs[KGDB_PPC_CTR_REG] = regs->ctr;
        gdb_regs[KGDB_PPC_XER_REG] = regs->xer;
}

/*
 * Reverse the above.
 */
void
kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
{
        regs->xer = gdb_regs[KGDB_PPC_XER_REG];
        regs->ctr = gdb_regs[KGDB_PPC_CTR_REG];
        regs->lr  = gdb_regs[KGDB_PPC_LR_REG];
        regs->cr  = gdb_regs[KGDB_PPC_CR_REG];
        regs->msr = gdb_regs[KGDB_PPC_MSR_REG];
        regs->iar = gdb_regs[KGDB_PPC_PC_REG];
        memcpy(regs, gdb_regs, 32 * sizeof(unsigned long));
}       

/*
 * Trap into kgdb to wait for debugger to connect,
 * noting on the console why nothing else is going on.
 */
void
kgdb_connect(int verbose)
{
        if (kgdb_dev == NODEV)
                return;

        if (verbose)
                printf("kgdb waiting...");

        __asm volatile(BKPT_ASM);

        if (verbose && kgdb_active) {
                printf("kgdb connected.\n");
        }

        kgdb_debug_panic = 1;
}

/*
 * Decide what to do on panic.
 * (This is called by panic, like Debugger())
 */
void
kgdb_panic(void)
{
        if (kgdb_dev != NODEV && kgdb_debug_panic) {
                printf("entering kgdb\n");
                kgdb_connect(kgdb_active == 0);
        }
}