/*
 * 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.
 */

#ifndef _SYS_CLOCK_TICK_H
#define _SYS_CLOCK_TICK_H

#include <sys/types.h>
#include <sys/mutex.h>
#include <sys/cpuvar.h>
#include <sys/systm.h>
#include <sys/cyclic.h>

#ifdef  __cplusplus
extern "C" {
#endif

#define CLOCK_TICK_NCPUS        32

/*
 * Per-CPU structure to facilitate multi-threaded tick accounting.
 *
 * ct_lock
 *      Mutex for the structure. Used to lock the structure to pass
 *      arguments to the tick processing softint handler.
 * ct_intr
 *      Tick processing softint handle. For parallelism, each CPU
 *      needs to have its own softint handle.
 * ct_lbolt
 *      Copy of the lbolt at the time of tick scheduling.
 * ct_pending
 *      Number of ticks to be processed by one invocation of the tick
 *      processing softint.
 * ct_start
 *      First CPU to do tick processing for.
 * ct_end
 *      Last CPU to do tick processing for.
 * ct_scan
 *      CPU to start the tick processing from. Rotated every tick.
 */
typedef struct clock_tick_cpu {
        kmutex_t                ct_lock;
        ulong_t                 ct_intr;
        clock_t                 ct_lbolt;
        int                     ct_pending;
        int                     ct_start;
        int                     ct_end;
        int                     ct_scan;
} clock_tick_cpu_t;

/*
 * Per-set structure to facilitate multi-threaded tick accounting.
 * clock_tick_lock protects this.
 *
 * ct_start
 *      First CPU to do tick processing for.
 * ct_end
 *      Last CPU to do tick processing for.
 * ct_scan
 *      CPU to start the tick processing from. Rotated every tick.
 */
typedef struct clock_tick_set {
        int                     ct_start;
        int                     ct_end;
        int                     ct_scan;
} clock_tick_set_t;

#define CLOCK_TICK_CPU_OFFLINE(cp)      \
        (((cp) != cpu_active) && ((cp)->cpu_next_onln == (cp)))

#define CLOCK_TICK_XCALL_SAFE(cp)       \
                CPU_IN_SET(clock_tick_online_cpuset, cp->cpu_id)

#define CLOCK_TICK_PROC_MAX             10

#ifdef  _KERNEL
#pragma weak            create_softint
extern ulong_t          create_softint(uint_t, uint_t (*)(caddr_t, caddr_t),
                                caddr_t);
#pragma weak            invoke_softint
extern void             invoke_softint(processorid_t, ulong_t);
#pragma weak            sync_softint
extern void             sync_softint(cpuset_t);
extern void             clock_tick(kthread_t *, int);
extern void             membar_sync(void);

extern int              hires_tick;
#endif  /* _KERNEL */

#ifdef  __cplusplus
}
#endif

#endif /* _SYS_CLOCK_TICK_H */