/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 Marcel Moolenaar
 * All rights reserved.
 *
 * 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 AUTHORS ``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 AUTHORS 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/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/reg.h>
#include <sys/signal.h>

#include <machine/cpufunc.h>
#include <machine/frame.h>
#include <machine/gdb_machdep.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/psl.h>
#include <machine/specialreg.h>
#include <machine/trap.h>
#include <machine/frame.h>
#include <machine/endian.h>

#include <gdb/gdb.h>
#include <gdb/gdb_int.h>

void *
gdb_cpu_getreg(int regnum, size_t *regsz)
{
        static uint32_t _kcodesel = GSEL(GCODE_SEL, SEL_KPL);
        static uint32_t _kdatasel = GSEL(GDATA_SEL, SEL_KPL);

        *regsz = gdb_cpu_regsz(regnum);

        if (kdb_thread  == curthread) {
                switch (regnum) {
                case GDB_REG_RAX: return (&kdb_frame->tf_rax);
                case GDB_REG_RCX: return (&kdb_frame->tf_rcx);
                case GDB_REG_RDX: return (&kdb_frame->tf_rdx);
                case GDB_REG_RSI: return (&kdb_frame->tf_rsi);
                case GDB_REG_RDI: return (&kdb_frame->tf_rdi);
                case GDB_REG_R8:  return (&kdb_frame->tf_r8);
                case GDB_REG_R9:  return (&kdb_frame->tf_r9);
                case GDB_REG_R10: return (&kdb_frame->tf_r10);
                case GDB_REG_R11: return (&kdb_frame->tf_r11);
                case GDB_REG_RFLAGS: return (&kdb_frame->tf_rflags);
                case GDB_REG_CS:  return (&kdb_frame->tf_cs);
                case GDB_REG_SS:  return (&kdb_frame->tf_ss);
                }
        }
        switch (regnum) {
        case GDB_REG_RBX: return (&kdb_thrctx->pcb_rbx);
        case GDB_REG_RBP: return (&kdb_thrctx->pcb_rbp);
        case GDB_REG_RSP: return (&kdb_thrctx->pcb_rsp);
        case GDB_REG_R12: return (&kdb_thrctx->pcb_r12);
        case GDB_REG_R13: return (&kdb_thrctx->pcb_r13);
        case GDB_REG_R14: return (&kdb_thrctx->pcb_r14);
        case GDB_REG_R15: return (&kdb_thrctx->pcb_r15);
        case GDB_REG_PC:  return (&kdb_thrctx->pcb_rip);
        case GDB_REG_CS:  return (&_kcodesel);
        case GDB_REG_SS:  return (&_kdatasel);
        }
        return (NULL);
}

void
gdb_cpu_setreg(int regnum, void *val)
{
        register_t regval = *(register_t *)val;

        /*
         * Write registers to the trapframe and pcb, if applicable.
         * Some scratch registers are not tracked by the pcb.
         */
        if (kdb_thread == curthread) {
                switch (regnum) {
                case GDB_REG_RAX: kdb_frame->tf_rax = regval; break;
                case GDB_REG_RBX: kdb_frame->tf_rbx = regval; break;
                case GDB_REG_RCX: kdb_frame->tf_rcx = regval; break;
                case GDB_REG_RDX: kdb_frame->tf_rdx = regval; break;
                case GDB_REG_RSI: kdb_frame->tf_rsi = regval; break;
                case GDB_REG_RDI: kdb_frame->tf_rdi = regval; break;
                case GDB_REG_RBP: kdb_frame->tf_rbp = regval; break;
                case GDB_REG_RSP: kdb_frame->tf_rsp = regval; break;
                case GDB_REG_R8:  kdb_frame->tf_r8  = regval; break;
                case GDB_REG_R9:  kdb_frame->tf_r9  = regval; break;
                case GDB_REG_R10: kdb_frame->tf_r10 = regval; break;
                case GDB_REG_R11: kdb_frame->tf_r11 = regval; break;
                case GDB_REG_R12: kdb_frame->tf_r12 = regval; break;
                case GDB_REG_R13: kdb_frame->tf_r13 = regval; break;
                case GDB_REG_R14: kdb_frame->tf_r14 = regval; break;
                case GDB_REG_R15: kdb_frame->tf_r15 = regval; break;
                case GDB_REG_PC:  kdb_frame->tf_rip = regval; break;
                }
        }
        switch (regnum) {
        case GDB_REG_RBX: kdb_thrctx->pcb_rbx = regval; break;
        case GDB_REG_RBP: kdb_thrctx->pcb_rbp = regval; break;
        case GDB_REG_RSP: kdb_thrctx->pcb_rsp = regval; break;
        case GDB_REG_R12: kdb_thrctx->pcb_r12 = regval; break;
        case GDB_REG_R13: kdb_thrctx->pcb_r13 = regval; break;
        case GDB_REG_R14: kdb_thrctx->pcb_r14 = regval; break;
        case GDB_REG_R15: kdb_thrctx->pcb_r15 = regval; break;
        case GDB_REG_PC:  kdb_thrctx->pcb_rip = regval; break;
        }
}

int
gdb_cpu_signal(int type, int code)
{

        switch (type) {
        case T_BPTFLT: return (SIGTRAP);
        case T_ARITHTRAP: return (SIGFPE);
        case T_PROTFLT: return (SIGSEGV);
        case T_TRCTRAP: return (SIGTRAP);
        case T_PAGEFLT: return (SIGSEGV);
        case T_DIVIDE: return (SIGFPE);
        case T_NMI: return (SIGTRAP);
        case T_FPOPFLT: return (SIGILL);
        case T_TSSFLT: return (SIGSEGV);
        case T_SEGNPFLT: return (SIGSEGV);
        case T_STKFLT: return (SIGSEGV);
        case T_XMMFLT: return (SIGFPE);
        }
        return (SIGEMT);
}

void
gdb_cpu_stop_reason(int type, int code)
{
        uintmax_t val;

        val = 0;
        if (type == T_TRCTRAP) {
                /* NB: 'code' contains the value of dr6 at the trap. */
                if ((code & DBREG_DR6_B(0)) != 0) {
                        val = rdr0();
                }
                if ((code & DBREG_DR6_B(1)) != 0) {
                        val = rdr1();
                }
                if ((code & DBREG_DR6_B(2)) != 0) {
                        val = rdr2();
                }
                if ((code & DBREG_DR6_B(3)) != 0) {
                        val = rdr3();
                }

                /*
                 * TODO: validate the bits in DR7 to differentiate between a
                 * watchpoint trap and a hardware breakpoint trap (currently
                 * unsupported).
                 */
                if (val != 0) {
                        gdb_tx_str("watch:");
                        gdb_tx_varhex(val);
                        gdb_tx_char(';');
                }
        }
}

void *
gdb_begin_write(void)
{

        return (disable_wp() ? &gdb_begin_write : NULL);
}

void
gdb_end_write(void *arg)
{

        restore_wp(arg != NULL);
}