/*      $OpenBSD: process_machdep.c,v 1.30 2023/01/30 10:49:05 jsg Exp $        */
/*      $NetBSD: process_machdep.c,v 1.22 1996/05/03 19:42:25 christos Exp $    */

/*
 * Copyright (c) 1995, 1996 Charles M. Hannum.  All rights reserved.
 * Copyright (c) 1993 The Regents of the University of California.
 * Copyright (c) 1993 Jan-Simon Pendry
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 * From:
 *      Id: procfs_i386.c,v 4.1 1993/12/17 10:47:45 jsp Rel
 */

/*
 * This file may seem a bit stylized, but that so that it's easier to port.
 * Functions to be implemented here are:
 *
 * process_read_regs(proc, regs)
 *      Get the current user-visible register set from the process
 *      and copy it into the regs structure (<machine/reg.h>).
 *      The process is stopped at the time read_regs is called.
 *
 * process_write_regs(proc, regs)
 *      Update the current register set from the passed in regs
 *      structure.  Take care to avoid clobbering special CPU
 *      registers or privileged bits in the PSL.
 *      The process is stopped at the time write_regs is called.
 *
 * process_sstep(proc)
 *      Arrange for the process to trap after executing a single instruction.
 *
 * process_set_pc(proc)
 *      Set the process's program counter.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/ptrace.h>

#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/segments.h>

#include "npx.h"

static __inline struct trapframe *process_frame(struct proc *);
static __inline union savefpu *process_fpframe(struct proc *);
void process_fninit_xmm(struct savexmm *);

static __inline struct trapframe *
process_frame(struct proc *p)
{

        return (p->p_md.md_regs);
}

static __inline union savefpu *
process_fpframe(struct proc *p)
{

        return (&p->p_addr->u_pcb.pcb_savefpu);
}

void
process_xmm_to_s87(const struct savexmm *sxmm, struct save87 *s87)
{
        int i;

        /* FPU control/status */
        s87->sv_env.en_cw = sxmm->sv_env.en_cw;
        s87->sv_env.en_sw = sxmm->sv_env.en_sw;
        /* tag word handled below */
        s87->sv_env.en_fip = sxmm->sv_env.en_fip;
        s87->sv_env.en_fcs = sxmm->sv_env.en_fcs;
        s87->sv_env.en_opcode = sxmm->sv_env.en_opcode;
        s87->sv_env.en_foo = sxmm->sv_env.en_foo;
        s87->sv_env.en_fos = sxmm->sv_env.en_fos;

        /* Tag word and registers. */
        for (i = 0; i < 8; i++) {
                if (sxmm->sv_env.en_tw & (1U << i))
                        s87->sv_env.en_tw &= ~(3U << (i * 2));
                else
                        s87->sv_env.en_tw |= (3U << (i * 2));

                if (sxmm->sv_ex_tw & (1U << i))
                        s87->sv_ex_tw &= ~(3U << (i * 2));
                else
                        s87->sv_ex_tw |= (3U << (i * 2));

                memcpy(&s87->sv_ac[i].fp_bytes, &sxmm->sv_ac[i].fp_bytes,
                    sizeof(s87->sv_ac[i].fp_bytes));
        }

        s87->sv_ex_sw = sxmm->sv_ex_sw;
}

void
process_fninit_xmm(struct savexmm *sxmm)
{
        memset(sxmm, 0, sizeof(*sxmm));
        sxmm->sv_env.en_cw = __INITIAL_NPXCW__;
        sxmm->sv_env.en_mxcsr = __INITIAL_MXCSR__;
        sxmm->sv_env.en_mxcsr_mask = fpu_mxcsr_mask;
        sxmm->sv_env.en_sw = 0x0000;
        sxmm->sv_env.en_tw = 0x00;
}

int
process_read_regs(struct proc *p, struct reg *regs)
{
        struct trapframe *tf = process_frame(p);

        regs->r_gs = tf->tf_gs & 0xffff;
        regs->r_fs = tf->tf_fs & 0xffff;
        regs->r_es = tf->tf_es & 0xffff;
        regs->r_ds = tf->tf_ds & 0xffff;
        regs->r_eflags = tf->tf_eflags;
        regs->r_edi = tf->tf_edi;
        regs->r_esi = tf->tf_esi;
        regs->r_ebp = tf->tf_ebp;
        regs->r_ebx = tf->tf_ebx;
        regs->r_edx = tf->tf_edx;
        regs->r_ecx = tf->tf_ecx;
        regs->r_eax = tf->tf_eax;
        regs->r_eip = tf->tf_eip;
        regs->r_cs = tf->tf_cs & 0xffff;
        regs->r_esp = tf->tf_esp;
        regs->r_ss = tf->tf_ss & 0xffff;

        return (0);
}

int
process_read_fpregs(struct proc *p, struct fpreg *regs)
{
        union savefpu *frame = process_fpframe(p);

        if (p->p_md.md_flags & MDP_USEDFPU) {
#if NNPX > 0
                npxsave_proc(p, 1);
#endif
        } else {
                /* Fake a FNINIT. */
                if (i386_use_fxsave) {
                        process_fninit_xmm(&frame->sv_xmm);
                } else {
                        memset(&frame->sv_87, 0, sizeof(frame->sv_87));
                        frame->sv_87.sv_env.en_cw = __INITIAL_NPXCW__;
                        frame->sv_87.sv_env.en_sw = 0x0000;
                        frame->sv_87.sv_env.en_tw = 0xffff;
                }
                p->p_md.md_flags |= MDP_USEDFPU;
        }

        if (i386_use_fxsave) {
                struct save87 s87;

                /* XXX Yuck */
                process_xmm_to_s87(&frame->sv_xmm, &s87);
                memcpy(regs, &s87, sizeof(*regs));
        } else
                memcpy(regs, &frame->sv_87, sizeof(*regs));

        return (0);
}

#ifdef PTRACE

void
process_s87_to_xmm(const struct save87 *s87, struct savexmm *sxmm)
{
        int i;

        /* FPU control/status */
        sxmm->sv_env.en_cw = s87->sv_env.en_cw;
        sxmm->sv_env.en_sw = s87->sv_env.en_sw;
        /* tag word handled below */
        sxmm->sv_env.en_fip = s87->sv_env.en_fip;
        sxmm->sv_env.en_fcs = s87->sv_env.en_fcs;
        sxmm->sv_env.en_opcode = s87->sv_env.en_opcode;
        sxmm->sv_env.en_foo = s87->sv_env.en_foo;
        sxmm->sv_env.en_fos = s87->sv_env.en_fos;

        /* Tag word and registers. */
        for (i = 0; i < 8; i++) {
                if (((s87->sv_env.en_tw >> (i * 2)) & 3) == 3)
                        sxmm->sv_env.en_tw &= ~(1U << i);
                else
                        sxmm->sv_env.en_tw |= (1U << i);

                if (((s87->sv_ex_tw >> (i * 2)) & 3) == 3)
                        sxmm->sv_ex_tw &= ~(1U << i);
                else
                        sxmm->sv_ex_tw |= (1U << i);

                memcpy(&sxmm->sv_ac[i].fp_bytes, &s87->sv_ac[i].fp_bytes,
                    sizeof(sxmm->sv_ac[i].fp_bytes));
        }

        sxmm->sv_ex_sw = s87->sv_ex_sw;
}

int
process_write_regs(struct proc *p, struct reg *regs)
{
        struct trapframe *tf = process_frame(p);

        /*
         * Check for security violations.
         */
        if (((regs->r_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
            !USERMODE(regs->r_cs, regs->r_eflags))
                return (EINVAL);

        tf->tf_gs = regs->r_gs & 0xffff;
        tf->tf_fs = regs->r_fs & 0xffff;
        tf->tf_es = regs->r_es & 0xffff;
        tf->tf_ds = regs->r_ds & 0xffff;
        tf->tf_eflags = regs->r_eflags;
        tf->tf_edi = regs->r_edi;
        tf->tf_esi = regs->r_esi;
        tf->tf_ebp = regs->r_ebp;
        tf->tf_ebx = regs->r_ebx;
        tf->tf_edx = regs->r_edx;
        tf->tf_ecx = regs->r_ecx;
        tf->tf_eax = regs->r_eax;
        tf->tf_eip = regs->r_eip;
        tf->tf_cs = regs->r_cs & 0xffff;
        tf->tf_esp = regs->r_esp;
        tf->tf_ss = regs->r_ss & 0xffff;

        return (0);
}

int
process_write_fpregs(struct proc *p, struct fpreg *regs)
{
        union savefpu *frame = process_fpframe(p);

        if (p->p_md.md_flags & MDP_USEDFPU) {
#if NNPX > 0
                npxsave_proc(p, 0);
#endif
        } else {
                /*
                 * Make sure MXCSR and the XMM registers are
                 * initialized to sane defaults.
                 */
                if (i386_use_fxsave)
                        process_fninit_xmm(&frame->sv_xmm);
                p->p_md.md_flags |= MDP_USEDFPU;
        }

        if (i386_use_fxsave) {
                struct save87 s87;

                /* XXX Yuck. */
                memcpy(&s87, regs, sizeof(*regs));
                process_s87_to_xmm(&s87, &frame->sv_xmm);
        } else
                memcpy(&frame->sv_87, regs, sizeof(*regs));

        return (0);
}

int
process_read_xmmregs(struct proc *p, struct xmmregs *regs)
{
        union savefpu *frame = process_fpframe(p);

        if (!i386_use_fxsave)
                return (EINVAL);

        if (p->p_md.md_flags & MDP_USEDFPU) {
#if NNPX > 0
                npxsave_proc(p, 1);
#endif
        } else {
                /* Fake a FNINIT. */
                process_fninit_xmm(&frame->sv_xmm);
                p->p_md.md_flags |= MDP_USEDFPU;
        }

        memcpy(regs, &frame->sv_xmm, sizeof(*regs));
        return (0);
}

int
process_write_xmmregs(struct proc *p, const struct xmmregs *regs)
{
        union savefpu *frame = process_fpframe(p);

        if (!i386_use_fxsave)
                return (EINVAL);

        if (p->p_md.md_flags & MDP_USEDFPU) {
#if NNPX > 0
                npxsave_proc(p, 0);
#endif
        } else
                p->p_md.md_flags |= MDP_USEDFPU;

        memcpy(&frame->sv_xmm, regs, sizeof(*regs));
        frame->sv_xmm.sv_env.en_mxcsr &= fpu_mxcsr_mask;
        return (0);
}

int
process_sstep(struct proc *p, int sstep)
{
        struct trapframe *tf = process_frame(p);

        if (sstep)
                tf->tf_eflags |= PSL_T;
        else
                tf->tf_eflags &= ~PSL_T;
        
        return (0);
}

int
process_set_pc(struct proc *p, caddr_t addr)
{
        struct trapframe *tf = process_frame(p);

        tf->tf_eip = (int)addr;

        return (0);
}

#endif  /* PTRACE */