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  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the next
  16  * paragraph) shall be included in all copies or substantial portions of the
  17  * Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  23  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  24  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  *
  27  * Authors:
  28  *    Rickard E. (Rik) Faith <faith@valinux.com>
  29  *
  30  */
  31
  32 #define __NO_VERSION__
  33 #include "drmP.h"
  34
  35 int                           drm_flags         = 0;
  36
  37 /* drm_parse_option parses a single option.  See description for
  38    drm_parse_options for details. */
  39
  40 static void drm_parse_option(char *s)
  41 {
  42         char *c, *r;
  43
  44         DRM_DEBUG("\"%s\"\n", s);
  45         if (!s || !*s) return;
  46         for (c = s; *c && *c != ':'; c++); /* find : or \0 */
  47         if (*c) r = c + 1; else r = NULL;  /* remember remainder */
  48         *c = '\0';                         /* terminate */
  49         if (!strcmp(s, "noctx")) {
  50                 drm_flags |= DRM_FLAG_NOCTX;
  51                 DRM_INFO("Server-mediated context switching OFF\n");
  52                 return;
  53         }
  54         if (!strcmp(s, "debug")) {
  55                 drm_flags |= DRM_FLAG_DEBUG;
  56                 DRM_INFO("Debug messages ON\n");
  57                 return;
  58         }
  59         DRM_ERROR("\"%s\" is not a valid option\n", s);
  60         return;
  61 }
  62
  63 /* drm_parse_options parse the insmod "drm=" options, or the command-line
  64  * options passed to the kernel via LILO.  The grammar of the format is as
  65  * follows:
  66  *
  67  * drm          ::= 'drm=' option_list
  68  * option_list  ::= option [ ';' option_list ]
  69  * option       ::= 'device:' major
  70  *              |   'debug'
  71  *              |   'noctx'
  72  * major        ::= INTEGER
  73  *
  74  * Note that 's' contains option_list without the 'drm=' part.
  75  *
  76  * device=major,minor specifies the device number used for /dev/drm
  77  *        if major == 0 then the misc device is used
  78  *        if major == 0 and minor == 0 then dynamic misc allocation is used
  79  * debug=on specifies that debugging messages will be printk'd
  80  * debug=trace specifies that each function call will be logged via printk
  81  * debug=off turns off all debugging options
  82  *
  83  */
  84
  85 void drm_parse_options(char *s)
  86 {
  87         char *h, *t, *n;
  88
  89         DRM_DEBUG("\"%s\"\n", s ?: "");
  90         if (!s || !*s) return;
  91
  92         for (h = t = n = s; h && *h; h = n) {
  93                 for (; *t && *t != ';'; t++);          /* find ; or \0 */
  94                 if (*t) n = t + 1; else n = NULL;      /* remember next */
  95                 *t = '\0';                             /* terminate */
  96                 drm_parse_option(h);                   /* parse */
  97         }
  98 }
  99
 100 /* drm_cpu_valid returns non-zero if the DRI will run on this CPU, and 0
 101  * otherwise. */
 102
 103 int drm_cpu_valid(void)
 104 {
 105 #if defined(__i386__)
 106         if (boot_cpu_data.x86 == 3) return 0; /* No cmpxchg on a 386 */
 107 #endif
 108 #if defined(__sparc__) && !defined(__sparc_v9__)
 109         if (1)
 110                 return 0; /* No cmpxchg before v9 sparc. */
 111 #endif
 112         return 1;
 113 }