/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1990 The Regents of the University of California.
 * 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. 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.
 */

#include <sys/cdefs.h>
#include "opt_capsicum.h"
#include "opt_ktrace.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/ktrace.h>
#include <sys/proc.h>
#include <sys/sysproto.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <machine/cpu.h>
#include <machine/sysarch.h>
#include <machine/machdep.h>
#include <machine/vmparam.h>

#ifndef _SYS_SYSPROTO_H_
struct sysarch_args {
        int op;
        char *parms;
};
#endif

/* Prototypes */
static int arm32_sync_icache (struct thread *, void *);
static int arm32_drain_writebuf(struct thread *, void *);

static int
sync_icache(uintptr_t addr, size_t len)
{
        size_t size;
        vm_offset_t rv;

         /* Align starting address to cacheline size */
        len += addr & cpuinfo.dcache_line_mask;
        addr &= ~cpuinfo.dcache_line_mask;

        /* Break whole range to pages. */
        do {
                size = PAGE_SIZE - (addr & PAGE_MASK);
                size = min(size, len);
                rv = dcache_wb_pou_checked(addr, size);
                if (rv == 1) /* see dcache_wb_pou_checked() */
                        rv = icache_inv_pou_checked(addr, size);
                if (rv != 1) {
                        if (!useracc((void *)addr, size, VM_PROT_READ)) {
                                /* Invalid access */
                                return (rv);
                        }
                        /* Valid but unmapped page - skip it. */
                }
                len -= size;
                addr += size;
        } while (len > 0);

        /* Invalidate branch predictor buffer. */
        bpb_inv_all();
        return (1);
}

static int
arm32_sync_icache(struct thread *td, void *args)
{
        struct arm_sync_icache_args ua;
        int error;
        ksiginfo_t ksi;
        vm_offset_t rv;

        if ((error = copyin(args, &ua, sizeof(ua))) != 0)
                return (error);

        if  (ua.len == 0) {
                td->td_retval[0] = 0;
                return (0);
        }

        /*
         * Validate arguments. Address and length are unsigned,
         * so we can use wrapped overflow check.
         */
        if (((ua.addr + ua.len) < ua.addr) ||
            ((ua.addr + ua.len) > VM_MAXUSER_ADDRESS)) {
                ksiginfo_init_trap(&ksi);
                ksi.ksi_signo = SIGSEGV;
                ksi.ksi_code = SEGV_ACCERR;
                ksi.ksi_addr = (void *)max(ua.addr, VM_MAXUSER_ADDRESS);
                trapsignal(td, &ksi);
                return (EINVAL);
        }

        rv = sync_icache(ua.addr, ua.len);
        if (rv != 1) {
                ksiginfo_init_trap(&ksi);
                ksi.ksi_signo = SIGSEGV;
                ksi.ksi_code = SEGV_MAPERR;
                ksi.ksi_addr = (void *)rv;
                trapsignal(td, &ksi);
                return (EINVAL);
        }

        td->td_retval[0] = 0;
        return (0);
}

static int
arm32_drain_writebuf(struct thread *td, void *args)
{
        /* No args. */

        dsb();
        cpu_l2cache_drain_writebuf();
        td->td_retval[0] = 0;
        return (0);
}

static int
arm32_set_tp(struct thread *td, void *args)
{

        set_tls(args);
        return (0);
}

static int
arm32_get_tp(struct thread *td, void *args)
{

        td->td_retval[0] = (register_t)get_tls();
        return (0);
}

int
sysarch(struct thread *td, struct sysarch_args *uap)
{
        int error;

#ifdef CAPABILITY_MODE
        /*
         * When adding new operations, add a new case statement here to
         * explicitly indicate whether or not the operation is safe to
         * perform in capability mode.
         */
        switch (uap->op) {
        case ARM_SYNC_ICACHE:
        case ARM_DRAIN_WRITEBUF:
        case ARM_SET_TP:
        case ARM_GET_TP:
        case ARM_GET_VFPSTATE:
                break;

        default:
                if (CAP_TRACING(td))
                        ktrcapfail(CAPFAIL_SYSCALL, &uap->op);
                if (IN_CAPABILITY_MODE(td))
                        return (ECAPMODE);
        }
#endif

        switch (uap->op) {
        case ARM_SYNC_ICACHE:
                error = arm32_sync_icache(td, uap->parms);
                break;
        case ARM_DRAIN_WRITEBUF:
                error = arm32_drain_writebuf(td, uap->parms);
                break;
        case ARM_SET_TP:
                error = arm32_set_tp(td, uap->parms);
                break;
        case ARM_GET_TP:
                error = arm32_get_tp(td, uap->parms);
                break;
        case ARM_GET_VFPSTATE:
                error = arm_get_vfpstate(td, uap->parms);
                break;
        default:
                error = EINVAL;
                break;
        }
        return (error);
}