sun4v/io/drctl_impl.c

	drctl_impl.c revision 99c7e85592b5d673f1469b2767f876710004dc23
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/door.h>
#include <sys/note.h>
#include <sys/drctl.h>
#include <sys/drctl_impl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/dr_util.h>

static door_handle_t drctl_dh;  /* Door for upcalls */


int
i_drctl_ioctl(int cmd, intptr_t arg)
{
    int rv;
    drctl_setup_t setup_rqst;

    switch (cmd) {
    case DRCTL_IOCTL_CONNECT_SERVER:
        if (ddi_copyin((caddr_t)arg,
            &setup_rqst, sizeof (setup_rqst), 0) != 0) {
            cmn_err(CE_WARN, "i_drctl_ioctl: ddi_copyin failed "
                "for DRCTL_IOCTL_CONNECT_SERVER");
            rv = EFAULT;
            break;
        }

        drctl_dh = door_ki_lookup(setup_rqst.did);
        rv = 0;
        break;

    default:
        rv = EIO;
    }

    return (rv);
}

int
i_drctl_send(void *msg, size_t size, void **obufp, size_t *osize)
{
    int up_err;
    int rv = 0;
    door_arg_t door_args;
    door_handle_t dh = drctl_dh;
    static const char me[] = "i_drctl_send";

retry:
    if (dh)
        door_ki_hold(dh);
    else
        return (EIO);

    door_args.data_ptr = (char *)msg;
    door_args.data_size = size;
    door_args.desc_ptr = NULL;
    door_args.desc_num = 0;

    /*
     * We don't know the size of the message the daemon
     * will pass back to us.  By setting rbuf to NULL,
     * we force the door code to allocate a buf of the
     * appropriate size.  We must set rsize > 0, however,
     * else the door code acts as if no response was
     * expected and doesn't pass the data to us.
     */
    door_args.rbuf = NULL;
    door_args.rsize = 1;
    DR_DBG_CTL("%s: msg %p size %ld obufp %p osize %p\n",
        me, msg, size, (void *)obufp, (void *)osize);

    up_err = door_ki_upcall_limited(dh, &door_args, NULL, SIZE_MAX, 0);
    if (up_err == 0) {
        if (door_args.rbuf == NULL)
            goto done;

        DR_DBG_CTL("%s: rbuf %p rsize %ld\n", me,
            (void *)door_args.rbuf, door_args.rsize);

        if (obufp != NULL) {
            *obufp = door_args.rbuf;
            *osize = door_args.rsize;
            DR_DBG_KMEM("%s: (door) alloc addr %p size %ld\n",
                __func__,
                (void *)(door_args.rbuf), door_args.rsize);
        } else {
            /*
             * No output buffer pointer was passed in,
             * so the response buffer allocated by the
             * door code must be deallocated.
             */
            DR_DBG_KMEM("%s: free addr %p size %ld\n", __func__,
                (void *)(door_args.rbuf), door_args.rsize);
            kmem_free(door_args.rbuf, door_args.rsize);
        }
    } else {
        switch (up_err) {
        case EINTR:
            DR_DBG_CTL("%s: door call returned EINTR\n", me);
            _NOTE(FALLTHROUGH)
        case EAGAIN:
            /*
             * Server process may be forking, try again.
             */
            door_ki_rele(dh);
            delay(hz);
            goto retry;
        case EBADF:
        case EINVAL:
            drctl_dh = NULL;
            DR_DBG_CTL(
                "%s: door call failed with %d\n", me, up_err);
            rv = EIO;
            break;
        default:
            DR_DBG_CTL("%s: unexpected return "
                "code %d from door_ki_upcall\n", me, up_err);
            rv = EIO;
            break;
        }
    }

done:
    door_ki_rele(dh);
    return (rv);
}