sys/rump/librump/rumpkern/percpu.c

   1 /*      $NetBSD: percpu.c,v 1.5 2009/03/18 10:22:44 cegger Exp $        */
   2
   3 /*
   4  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __KERNEL_RCSID(0, "$NetBSD: percpu.c,v 1.5 2009/03/18 10:22:44 cegger Exp $");
  30
  31 #include <sys/param.h>
  32 #include <sys/kmem.h>
  33 #include <sys/mutex.h>
  34 #include <sys/percpu.h>
  35
  36 #include "rump_private.h"
  37
  38 /*
  39  * A poor-man's userspace percpu emulation.  Since we can't disable
  40  * preemption currently, use a mutex.  Not the world's most efficient
  41  * method, but quite enough.  Hence, we can have only one cpu.
  42  */
  43
  44 static kmutex_t pcmtx;
  45
  46 void
  47 percpu_init(void)
  48 {
  49
  50         mutex_init(&pcmtx, MUTEX_DEFAULT, IPL_NONE);
  51 }
  52
  53 void *
  54 percpu_getref(percpu_t *pc)
  55 {
  56
  57         mutex_enter(&pcmtx);
  58         return pc;
  59 }
  60
  61 void
  62 percpu_putref(percpu_t *pc)
  63 {
  64
  65         mutex_exit(&pcmtx);
  66 }
  67
  68 percpu_t *
  69 percpu_alloc(size_t size)
  70 {
  71
  72         return kmem_alloc(size, KM_SLEEP);
  73 }
  74
  75 void
  76 percpu_free(percpu_t *pc, size_t size)
  77 {
  78
  79         kmem_free(pc, size);
  80 }
  81
  82 void
  83 percpu_foreach(percpu_t *pc, percpu_callback_t cb, void *arg)
  84 {
  85
  86         cb(pc, arg, rump_cpu);
  87 }