1 /* drm_init.h -- Setup/Cleanup for DRM -*- linux-c -*-
2  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.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  * VA LINUX SYSTEMS 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
25  * OTHER DEALINGS IN THE SOFTWARE.
26  *
27  * Authors:
28  *    Rickard E. (Rik) Faith <faith@valinux.com>
29  *    Gareth Hughes <gareth@valinux.com>
30  */
31 
32 #include "drmP.h"
33 
34 #if 0
35 int DRM(flags) = DRM_FLAG_DEBUG;
36 #else
37 int DRM(flags) = 0;
38 #endif
39 
40 /* drm_parse_option parses a single option.  See description for
41  * drm_parse_options for details.
42  */
DRM(parse_option)43 static void DRM(parse_option)(char *s)
44 {
45 	char *c, *r;
46 
47 	DRM_DEBUG("\"%s\"\n", s);
48 	if (!s || !*s) return;
49 	for (c = s; *c && *c != ':'; c++); /* find : or \0 */
50 	if (*c) r = c + 1; else r = NULL;  /* remember remainder */
51 	*c = '\0';			   /* terminate */
52 	if (!strcmp(s, "noctx")) {
53 		DRM(flags) |= DRM_FLAG_NOCTX;
54 		DRM_INFO("Server-mediated context switching OFF\n");
55 		return;
56 	}
57 	if (!strcmp(s, "debug")) {
58 		DRM(flags) |= DRM_FLAG_DEBUG;
59 		DRM_INFO("Debug messages ON\n");
60 		return;
61 	}
62 	DRM_ERROR("\"%s\" is not a valid option\n", s);
63 	return;
64 }
65 
66 /* drm_parse_options parse the insmod "drm_opts=" options, or the command-line
67  * options passed to the kernel via LILO.  The grammar of the format is as
68  * follows:
69  *
70  * drm		::= 'drm_opts=' option_list
71  * option_list	::= option [ ';' option_list ]
72  * option	::= 'device:' major
73  *		|   'debug'
74  *		|   'noctx'
75  * major	::= INTEGER
76  *
77  * Note that 's' contains option_list without the 'drm_opts=' part.
78  *
79  * device=major,minor specifies the device number used for /dev/drm
80  *	  if major == 0 then the misc device is used
81  *	  if major == 0 and minor == 0 then dynamic misc allocation is used
82  * debug=on specifies that debugging messages will be printk'd
83  * debug=trace specifies that each function call will be logged via printk
84  * debug=off turns off all debugging options
85  *
86  */
87 
DRM(parse_options)88 void DRM(parse_options)(char *s)
89 {
90 	char *h, *t, *n;
91 
92 	DRM_DEBUG("\"%s\"\n", s ?: "");
93 	if (!s || !*s) return;
94 
95 	for (h = t = n = s; h && *h; h = n) {
96 		for (; *t && *t != ';'; t++);	       /* find ; or \0 */
97 		if (*t) n = t + 1; else n = NULL;      /* remember next */
98 		*t = '\0';			       /* terminate */
99 		DRM(parse_option)(h);		       /* parse */
100 	}
101 }
102 
103 /* drm_cpu_valid returns non-zero if the DRI will run on this CPU, and 0
104  * otherwise.
105  */
DRM(cpu_valid)106 int DRM(cpu_valid)(void)
107 {
108 #if defined(__i386__)
109 	if (boot_cpu_data.x86 == 3) return 0; /* No cmpxchg on a 386 */
110 #endif
111 #if defined(__sparc__) && !defined(__sparc_v9__)
112 	return 0; /* No cmpxchg before v9 sparc. */
113 #endif
114 	return 1;
115 }
116