The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/dev/sound/unit.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2007 Ariff Abdullah <ariff@FreeBSD.org>
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  * $FreeBSD: stable/12/sys/dev/sound/unit.c 326255 2017-11-27 14:52:40Z pfg $
   29  */
   30 
   31 #include <sys/param.h>
   32 #include <sys/systm.h>
   33 
   34 #ifdef HAVE_KERNEL_OPTION_HEADERS
   35 #include "opt_snd.h"
   36 #endif
   37 
   38 #include <dev/sound/unit.h>
   39 
   40 /*
   41  * Unit magic allocator for sound driver.
   42  *
   43  * 'u' = Unit of attached soundcards
   44  * 'd' = Device type
   45  * 'c' = Channel number
   46  *
   47  * eg: dsp0.p1  - u=0, d=p, c=1
   48  *     dsp1.vp0 - u=1, d=vp, c=0
   49  *     dsp0.10  - u=0, d=clone, c=allocated clone (see further explanation)
   50  *
   51  * Maximum unit of soundcards can be tuned through "hw.snd.maxunit", which
   52  * is between SND_UNIT_UMIN (16) and SND_UNIT_UMAX (2048). By design,
   53  * maximum allowable allocated channel is 256, with exception for clone
   54  * devices which doesn't have any notion of channel numbering. The use of
   55  * channel numbering in a clone device is simply to provide uniqueness among
   56  * allocated clones. This also means that the maximum allowable clonable
   57  * device is largely dependant and dynamically tuned depending on
   58  * hw.snd.maxunit.
   59  */
   60 
   61 /* Default width */
   62 static int snd_u_shift = 9;     /* 0 - 0x1ff :  512 distinct soundcards   */
   63 static int snd_d_shift = 5;     /* 0 - 0x1f  :   32 distinct device types */
   64 static int snd_c_shift = 10;    /* 0 - 0x3ff : 1024 distinct channels
   65                                                (256 limit "by design",
   66                                                except for clone devices)  */
   67 
   68 static int snd_unit_initialized = 0;
   69 
   70 #ifdef SND_DIAGNOSTIC
   71 #define SND_UNIT_ASSERT()       do {                                    \
   72         if (snd_unit_initialized == 0)                                  \
   73                 panic("%s(): Uninitialized sound unit!", __func__);     \
   74 } while (0)
   75 #else
   76 #define SND_UNIT_ASSERT()       KASSERT(snd_unit_initialized != 0,      \
   77                                 ("%s(): Uninitialized sound unit!",     \
   78                                 __func__))
   79 #endif
   80 
   81 #define MKMASK(x)       ((1 << snd_##x##_shift) - 1)
   82 
   83 int
   84 snd_max_u(void)
   85 {
   86         SND_UNIT_ASSERT();
   87 
   88         return (MKMASK(u));
   89 }
   90 
   91 int
   92 snd_max_d(void)
   93 {
   94         SND_UNIT_ASSERT();
   95 
   96         return (MKMASK(d));
   97 }
   98 
   99 int
  100 snd_max_c(void)
  101 {
  102         SND_UNIT_ASSERT();
  103 
  104         return (MKMASK(c));
  105 }
  106 
  107 int
  108 snd_unit2u(int unit)
  109 {
  110         SND_UNIT_ASSERT();
  111 
  112         return ((unit >> (snd_c_shift + snd_d_shift)) & MKMASK(u));
  113 }
  114 
  115 int
  116 snd_unit2d(int unit)
  117 {
  118         SND_UNIT_ASSERT();
  119 
  120         return ((unit >> snd_c_shift) & MKMASK(d));
  121 }
  122 
  123 int
  124 snd_unit2c(int unit)
  125 {
  126         SND_UNIT_ASSERT();
  127 
  128         return (unit & MKMASK(c));
  129 }
  130 
  131 int
  132 snd_u2unit(int u)
  133 {
  134         SND_UNIT_ASSERT();
  135 
  136         return ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift));
  137 }
  138 
  139 int
  140 snd_d2unit(int d)
  141 {
  142         SND_UNIT_ASSERT();
  143 
  144         return ((d & MKMASK(d)) << snd_c_shift);
  145 }
  146 
  147 int
  148 snd_c2unit(int c)
  149 {
  150         SND_UNIT_ASSERT();
  151 
  152         return (c & MKMASK(c));
  153 }
  154 
  155 int
  156 snd_mkunit(int u, int d, int c)
  157 {
  158         SND_UNIT_ASSERT();
  159 
  160         return ((c & MKMASK(c)) | ((d & MKMASK(d)) << snd_c_shift) |
  161             ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift)));
  162 }
  163 
  164 /*
  165  * This *must* be called first before any of the functions above!!!
  166  */
  167 void
  168 snd_unit_init(void)
  169 {
  170         int i;
  171 
  172         if (snd_unit_initialized != 0)
  173                 return;
  174 
  175         snd_unit_initialized = 1;
  176 
  177         if (getenv_int("hw.snd.maxunit", &i) != 0) {
  178                 if (i < SND_UNIT_UMIN)
  179                         i = SND_UNIT_UMIN;
  180                 else if (i > SND_UNIT_UMAX)
  181                         i = SND_UNIT_UMAX;
  182                 else
  183                         i = roundup2(i, 2);
  184 
  185                 for (snd_u_shift = 0; (i >> (snd_u_shift + 1)) != 0;
  186                     snd_u_shift++)
  187                         ;
  188 
  189                 /*
  190                  * Make room for channels/clones allocation unit
  191                  * to fit within 24bit MAXMINOR limit.
  192                  */
  193                 snd_c_shift = 24 - snd_u_shift - snd_d_shift;
  194         }
  195 
  196         if (bootverbose != 0)
  197                 printf("%s() u=0x%08x [%d] d=0x%08x [%d] c=0x%08x [%d]\n",
  198                     __func__, SND_U_MASK, snd_max_u() + 1,
  199                     SND_D_MASK, snd_max_d() + 1, SND_C_MASK, snd_max_c() + 1);
  200 }

Cache object: 997ca3ab147a48180b8c41789f9b2fc1


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.