/*      $NetBSD: ast.c,v 1.34 2026/04/28 05:51:14 skrll Exp $   */

/*
 * Copyright (c) 1994,1995 Mark Brinicombe
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the RiscBSD team.
 * 4. The name of the company nor the name of the author may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * 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 OR CONTRIBUTERS 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.
 *
 * RiscBSD kernel project
 *
 * ast.c
 *
 * Code to handle ast's and returns to user mode
 *
 * Created      : 11/10/94
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ast.c,v 1.34 2026/04/28 05:51:14 skrll Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/cpu.h>
#include <sys/proc.h>
#include <sys/acct.h>
#include <sys/systm.h>
#include <sys/atomic.h>
#include <sys/kernel.h>
#include <sys/signal.h>
#include <sys/userret.h>
#include <sys/vmmeter.h>

#include <arm/locore.h>

#include <uvm/uvm_extern.h>

/*
 * Prototypes
 */
void ast(struct trapframe *);
 
void
userret(struct lwp *l)
{
#if defined(ARM_MMU_EXTENDED)
        KASSERTMSG(curcpu()->ci_pmap_cur == l->l_proc->p_vmspace->vm_map.pmap,
            "%p vs %p", curcpu()->ci_pmap_cur,
            l->l_proc->p_vmspace->vm_map.pmap);

        KASSERT(
            (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
            (armreg_ttbcr_read() & TTBCR_S_PD0) == 0
        );
#endif

        /* Invoke MI userret code */
        mi_userret(l);

        KASSERT(VALID_PSR(lwp_trapframe(l)->tf_spsr));
}


/*
 * Handle asynchronous system traps.
 * This is called from the irq handler to deliver signals
 * and switch processes if required.
 */

void
ast(struct trapframe *tf)
{
        struct lwp * const l = curlwp;

        /* Interrupts were restored by exception_exit. */

        KASSERT(VALID_PSR(tf->tf_spsr));

#ifdef __HAVE_PREEMPTION
        kpreempt_disable();
#endif
        struct cpu_info * const ci = curcpu();

        ci->ci_data.cpu_ntrap++;

        KDASSERT(ci->ci_cpl == IPL_NONE);
#ifdef __HAVE_PREEMPTION
        kpreempt_enable();
#endif

        if (l->l_pflag & LP_OWEUPC) {
                l->l_pflag &= ~LP_OWEUPC;
                ADDUPROF(l);
        }

        userret(l);
}