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dmover_process.c revision 1.2.18.1 
      1 /*	$NetBSD: dmover_process.c,v 1.2.18.1 2007/10/27 11:30:13 yamt Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * dmover_process.c: Processing engine for dmover-api.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: dmover_process.c,v 1.2.18.1 2007/10/27 11:30:13 yamt Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/proc.h>
     48 #include <sys/intr.h>
     49 
     50 #include <dev/dmover/dmovervar.h>
     51 
     52 TAILQ_HEAD(, dmover_request) dmover_completed_q;
     53 struct simplelock dmover_completed_q_slock;	/* must be held at splbio */
     54 
     55 void	*dmover_completed_si;
     56 
     57 void	dmover_complete(void *);
     58 
     59 /*
     60  * dmover_process_init:
     61  *
     62  *	Initialize the processing engine.
     63  */
     64 void
     65 dmover_process_initialize(void)
     66 {
     67 
     68 	TAILQ_INIT(&dmover_completed_q);
     69 	simple_lock_init(&dmover_completed_q_slock);
     70 
     71 	dmover_completed_si = softint_establish(SOFTINT_CLOCK,
     72 	    dmover_complete, NULL);
     73 }
     74 
     75 /*
     76  * dmover_process:	[client interface function]
     77  *
     78  *	Submit a tranform request for processing.
     79  */
     80 void
     81 dmover_process(struct dmover_request *dreq)
     82 {
     83 	struct dmover_session *dses = dreq->dreq_session;
     84 	struct dmover_assignment *das;
     85 	struct dmover_backend *dmb;
     86 	int s;
     87 
     88 #ifdef DIAGNOSTIC
     89 	if ((dreq->dreq_flags & DMOVER_REQ_WAIT) != 0 &&
     90 	    dreq->dreq_callback != NULL)
     91 		panic("dmover_process: WAIT used with callback");
     92 #endif
     93 
     94 	/* Clear unwanted flag bits. */
     95 	dreq->dreq_flags &= __DMOVER_REQ_FLAGS_PRESERVE;
     96 
     97 	s = splbio();
     98 
     99 	/* XXXLOCK */
    100 
    101 	/* XXX Right now, the back-end is statically assigned. */
    102 	das = &dses->__dses_assignment;
    103 
    104 	dmb = das->das_backend;
    105 	dreq->dreq_assignment = das;
    106 
    107 	dmover_session_insque(dses, dreq);
    108 	dmover_backend_insque(dmb, dreq);
    109 
    110 	/* XXXUNLOCK */
    111 
    112 	splx(s);
    113 
    114 	/* Kick the back-end into action. */
    115 	(*dmb->dmb_process)(das->das_backend);
    116 
    117 	if (dreq->dreq_flags & DMOVER_REQ_WAIT) {
    118 		s = splbio();
    119 		/* XXXLOCK */
    120 		while ((dreq->dreq_flags & DMOVER_REQ_DONE) == 0)
    121 			(void) tsleep(dreq, PRIBIO, "dmover", 0);
    122 		/* XXXUNLOCK */
    123 		splx(s);
    124 	}
    125 }
    126 
    127 /*
    128  * dmover_done:		[back-end interface function]
    129  *
    130  *	Back-end notification that the dmover is done.
    131  */
    132 void
    133 dmover_done(struct dmover_request *dreq)
    134 {
    135 	struct dmover_session *dses = dreq->dreq_session;
    136 	int s;
    137 
    138 	s = splbio();
    139 
    140 	/* XXXLOCK */
    141 
    142 	dmover_session_remque(dses, dreq);
    143 	/* backend has removed it from its queue */
    144 
    145 	/* XXXUNLOCK */
    146 
    147 	dreq->dreq_flags |= DMOVER_REQ_DONE;
    148 	dreq->dreq_flags &= ~DMOVER_REQ_RUNNING;
    149 	dreq->dreq_assignment = NULL;
    150 
    151 	if (dreq->dreq_callback != NULL) {
    152 		simple_lock(&dmover_completed_q_slock);
    153 		TAILQ_INSERT_TAIL(&dmover_completed_q, dreq, dreq_dmbq);
    154 		simple_unlock(&dmover_completed_q_slock);
    155 		softint_schedule(dmover_completed_si);
    156 	} else if (dreq->dreq_flags & DMOVER_REQ_WAIT)
    157 		wakeup(dreq);
    158 
    159 	splx(s);
    160 }
    161 
    162 /*
    163  * dmover_complete:
    164  *
    165  *	Complete a request by invoking the callback.
    166  */
    167 void
    168 dmover_complete(void *arg)
    169 {
    170 	struct dmover_request *dreq;
    171 	int s;
    172 
    173 	for (;;) {
    174 		s = splbio();
    175 		simple_lock(&dmover_completed_q_slock);
    176 		if ((dreq = TAILQ_FIRST(&dmover_completed_q)) != NULL)
    177 			TAILQ_REMOVE(&dmover_completed_q, dreq, dreq_dmbq);
    178 		simple_unlock(&dmover_completed_q_slock);
    179 		splx(s);
    180 
    181 		if (dreq == NULL)
    182 			return;
    183 
    184 		(*dreq->dreq_callback)(dreq);
    185 	}
    186 }
    187