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 
drm_parse_option(char * s)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 
drm_parse_options(char * s)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 
drm_cpu_valid(void)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 }
114