ns/nsctl/nsc_power.c

	nsc_power.c revision fcf3ce441efd61da9bb2884968af01cb7c1452cc
/*
 * 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/ksynch.h>
#include <sys/kmem.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/cred.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/cmn_err.h>

#define __NSC_GEN__
#include "nsc_dev.h"
#include "nsc_ioctl.h"
#include "nsc_power.h"
#include "../nsctl.h"

extern nsc_mem_t *_nsc_local_mem;
static  int null_power(void);


typedef struct _nsc_power_s {
    struct _nsc_power_s *next;  /* chain */
    char *name;         /* module name */
    void (*pw_power_lost)(int); /* callback power lost(rideout) */
    void (*pw_power_ok)(void);  /* callback power ok */
    void (*pw_power_down)(void);
                /* callback power down (shutdown imminent) */
} _nsc_power_t;

#define _P(x)   (((long)(&((_nsc_power_t *)0)->x))/sizeof (long))

static nsc_def_t _nsc_power_def[] = {
    "Power_Lost",   (uintptr_t)null_power,  _P(pw_power_lost),
    "Power_OK", (uintptr_t)null_power,  _P(pw_power_ok),
    "Power_Down",   (uintptr_t)null_power,  _P(pw_power_down),
    0,      0,          0,
};

static _nsc_power_t *_power_clients;
static kmutex_t _power_mutex;


static int null_power(void)
/*
 * init null_power - dummy power routine for clients that choose not
 * to implement all the power hooks.
 *
 */
{
    return (0);
}

/*
 * int
 * _nsc_power
 *  Call registered clients of the generic power ioctls.
 *
 * Calling/Exit State:
 *  Calls all the registered clients with a message describing the
 *      current state of the power for the system.
 */
int
_nsc_power(blind_t argp, int *rvp)
{
    nsc_power_ctl_t opc;
    _nsc_power_t *pp;

    *rvp = 0;
    if (copyin((void *) argp, &opc, sizeof (nsc_power_ctl_t)))
        return (EFAULT);
    mutex_enter(&_power_mutex);

    pp = _power_clients;
    while (pp) {
        switch ((nsc_power_ops_t)opc.msg) {

    case Power_OK:
            (*pp->pw_power_ok)();
            break;

    case Power_Down:
            (*pp->pw_power_down)();
            break;

    case Power_Lost:
            (*pp->pw_power_lost)(opc.arg1);
            break;

    default:
            mutex_exit(&_power_mutex);
            return (EINVAL);
        }

        pp = pp->next;
    }
    mutex_exit(&_power_mutex);
    return (0);
}

/*
 * int
 * _nsc_init_power (void)
 *  Initialise power ioctl subsystem.
 *
 * Calling/Exit State:
 *  Called at driver initialisation time to allocate necessary
 *  data structures.
 */
int
_nsc_init_power(void)
{
    mutex_init(&_power_mutex, NULL, MUTEX_DRIVER, NULL);
    return (0);
}

/*
 * int
 * _nsc_deinit_power (void)
 *  Initialise power ioctl subsystem.
 *
 * Calling/Exit State:
 *  Called at driver initialisation time to allocate necessary
 *  data structures.
 */
int
_nsc_deinit_power(void)
{
    _nsc_power_t *pp, *npp;

    mutex_enter(&_power_mutex);
    pp = _power_clients;
    while (pp) {
        npp = pp->next;
        nsc_kmem_free(pp, sizeof (_nsc_power_t));
        pp = npp;
    }
    _power_clients = NULL;
    mutex_exit(&_power_mutex);
    mutex_destroy(&_power_mutex);
    return (0);
}

/*
 * blind_t
 * nsc_register_power (char *name, nsc_def_t *def)
 *  Register an power ioctl client.
 *
 * Calling/Exit State:
 *  Returns a token for use in future calls to nsc_unregister_power.
 *      If a client with the same name is already registered then NULL
 *      is return to indicate failure.
 *  If registration fails NULL is returned.
 *
 * Description:
 *  Registers an power ioctl client for notifications during subsequent
 *      ioctl from UPS/PCU management.
 */
blind_t
nsc_register_power(char *name, nsc_def_t *def)
{
    _nsc_power_t *entry, *pp;


    entry = nsc_kmem_alloc(sizeof (_nsc_power_t), 0, _nsc_local_mem);

    if (entry == NULL)
        return (NULL);
    nsc_decode_param(def, _nsc_power_def, (long *)entry);

    mutex_enter(&_power_mutex);

    for (pp = _power_clients; pp; pp = pp->next) {
        if (strcmp(pp->name, name) == 0) {
            mutex_exit(&_power_mutex);
            nsc_kmem_free(entry, sizeof (_nsc_power_t));
            return (NULL);
        }
    }
    entry->name = name;

    entry->next = _power_clients;
    _power_clients = entry;
    mutex_exit(&_power_mutex);
    return ((blind_t)entry);
}

/*
 * int
 * nsc_unregister_power (blind_t powerp)
 *  Un-register a power ioctl client.
 *
 * Calling/Exit State:
 *  Returns 0 on success, otherwise returns an error code.
 *
 * Description:
 *  The specified power ioctl client is un-registered if possible.
 *      Zero is returned on success otherwise an error code.
 */
int
nsc_unregister_power(blind_t powerp)
{
    _nsc_power_t **xpp, *entry;

    entry = (_nsc_power_t *)powerp;
    if (entry == NULL)
        return (EINVAL);

    mutex_enter(&_power_mutex);

    for (xpp = &_power_clients; *xpp; xpp = &(*xpp)->next)
        if (*xpp == entry)
            break;

    if (*xpp == NULL) {
        mutex_exit(&_power_mutex);
        return (EALREADY);
    }
    *xpp = entry->next;
    mutex_exit(&_power_mutex);
    nsc_kmem_free(entry, sizeof (_nsc_power_t));

    return (0);
}