drivers/char/drm/init.c

   1 /* init.c -- Setup/Cleanup for DRM -*- linux-c -*-
   2  * Created: Mon Jan  4 08:58:31 1999 by faith@precisioninsight.com
   3  *
   4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the next
  15  * paragraph) shall be included in all copies or substantial portions of the
  16  * Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * Authors:
  27  *    Rickard E. (Rik) Faith <faith@precisioninsight.com>
  28  *
  29  */
  30
  31 #define __NO_VERSION__
  32 #include "drmP.h"
  33
  34 int                           drm_flags         = 0;
  35
  36 /* drm_parse_option parses a single option.  See description for
  37    drm_parse_options for details. */
  38
  39 static void drm_parse_option(char *s)
  40 {
  41         char *c, *r;
  42
  43         DRM_DEBUG("\"%s\"\n", s);
  44         if (!s || !*s) return;
  45         for (c = s; *c && *c != ':'; c++); /* find : or \0 */
  46         if (*c) r = c + 1; else r = NULL;  /* remember remainder */
  47         *c = '\0';                         /* terminate */
  48         if (!strcmp(s, "noctx")) {
  49                 drm_flags |= DRM_FLAG_NOCTX;
  50                 DRM_INFO("Server-mediated context switching OFF\n");
  51                 return;
  52         }
  53         if (!strcmp(s, "debug")) {
  54                 drm_flags |= DRM_FLAG_DEBUG;
  55                 DRM_INFO("Debug messages ON\n");
  56                 return;
  57         }
  58         DRM_ERROR("\"%s\" is not a valid option\n", s);
  59         return;
  60 }
  61
  62 /* drm_parse_options parse the insmod "drm=" options, or the command-line
  63  * options passed to the kernel via LILO.  The grammar of the format is as
  64  * follows:
  65  *
  66  * drm          ::= 'drm=' option_list
  67  * option_list  ::= option [ ';' option_list ]
  68  * option       ::= 'device:' major
  69  *              |   'debug'
  70  *              |   'noctx'
  71  * major        ::= INTEGER
  72  *
  73  * Note that 's' contains option_list without the 'drm=' part.
  74  *
  75  * device=major,minor specifies the device number used for /dev/drm
  76  *        if major == 0 then the misc device is used
  77  *        if major == 0 and minor == 0 then dynamic misc allocation is used
  78  * debug=on specifies that debugging messages will be printk'd
  79  * debug=trace specifies that each function call will be logged via printk
  80  * debug=off turns off all debugging options
  81  *
  82  */
  83
  84 void drm_parse_options(char *s)
  85 {
  86         char *h, *t, *n;
  87
  88         DRM_DEBUG("\"%s\"\n", s ?: "");
  89         if (!s || !*s) return;
  90
  91         for (h = t = n = s; h && *h; h = n) {
  92                 for (; *t && *t != ';'; t++);          /* find ; or \0 */
  93                 if (*t) n = t + 1; else n = NULL;      /* remember next */
  94                 *t = '\0';                             /* terminate */
  95                 drm_parse_option(h);                   /* parse */
  96         }
  97 }
  98
  99 /* drm_cpu_valid returns non-zero if the DRI will run on this CPU, and 0
 100  * otherwise. */
 101
 102 int drm_cpu_valid(void)
 103 {
 104 #if defined(__i386__)
 105         if (boot_cpu_data.x86 == 3) return 0; /* No cmpxchg on a 386 */
 106 #endif
 107 #if defined(__sparc__) && !defined(__sparc_v9__)
 108         if (1)
 109                 return 0; /* No cmpxchg before v9 sparc. */
 110 #endif
 111         return 1;
 112 }