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dmover_request.c revision 1.3 
      1 /*	$NetBSD: dmover_request.c,v 1.3 2007/11/07 00:23:18 ad 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_request.c: Request management functions for dmover-api.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: dmover_request.c,v 1.3 2007/11/07 00:23:18 ad Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/lock.h>
     47 #include <sys/pool.h>
     48 #include <sys/systm.h>
     49 #include <sys/malloc.h>
     50 
     51 #include <dev/dmover/dmovervar.h>
     52 
     53 pool_cache_t dmover_request_cache;
     54 
     55 static int initialized;
     56 static struct simplelock initialized_slock = SIMPLELOCK_INITIALIZER;
     57 
     58 void
     59 dmover_request_initialize(void)
     60 {
     61 	int s;
     62 
     63 	s = splbio();
     64 	simple_lock(&initialized_slock);
     65 	if (__predict_true(initialized == 0)) {
     66 		dmover_request_cache =
     67 		    pool_cache_init(sizeof(struct dmover_request), 0, 0, 0,
     68 		        "dmreq", NULL, IPL_BIO, NULL, NULL, NULL);
     69 		initialized = 1;
     70 	}
     71 	simple_unlock(&initialized_slock);
     72 	splx(s);
     73 }
     74 
     75 /*
     76  * dmover_request_alloc:	[client interface function]
     77  *
     78  *	Allocate a tranform request for the specified session.
     79  */
     80 struct dmover_request *
     81 dmover_request_alloc(struct dmover_session *dses, dmover_buffer *inbuf)
     82 {
     83 	struct dmover_request *dreq;
     84 	int inputs = dses->dses_ninputs;
     85 
     86 	if (__predict_false(initialized == 0)) {
     87 		int error;
     88 
     89 		s = splbio();
     90 		simple_lock(&initialized_slock);
     91 		error = (initialized == 0);
     92 		simple_unlock(&initialized_slock);
     93 		splx(s);
     94 
     95 		if (error)
     96 			return (NULL);
     97 	}
     98 
     99 	dreq = pool_cache_get(dmover_request_cache, PR_NOWAIT);
    100 	if (dreq == NULL)
    101 		return (NULL);
    102 
    103 	memset(dreq, 0, sizeof(*dreq));
    104 
    105 	if (inputs != 0) {
    106 		if (inbuf == NULL) {
    107 			inbuf = malloc(sizeof(dmover_buffer) * inputs,
    108 			    M_DEVBUF, M_NOWAIT);
    109 			if (inbuf == NULL) {
    110 				pool_cache_put(dmover_request_cache, dreq);
    111 				return (NULL);
    112 			}
    113 		}
    114 		dreq->dreq_flags |= __DMOVER_REQ_INBUF_FREE;
    115 		dreq->dreq_inbuf = inbuf;
    116 	}
    117 
    118 	dreq->dreq_session = dses;
    119 
    120 	return (dreq);
    121 }
    122 
    123 /*
    124  * dmover_request_free:		[client interface function]
    125  *
    126  *	Free a dmover request.
    127  */
    128 void
    129 dmover_request_free(struct dmover_request *dreq)
    130 {
    131 
    132 	if (dreq->dreq_flags & __DMOVER_REQ_INBUF_FREE)
    133 		free(dreq->dreq_inbuf, M_DEVBUF);
    134 
    135 	pool_cache_put(dmover_request_cache, dreq);
    136 }
    137