drivers/char/drm/init.c

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 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 voiddrm_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 voiddrm_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 intdrm_cpu_valid(void)
 104 {
 105 #if defined(__i386__)
 106 if(boot_cpu_data.x86 ==3)return0;/* No cmpxchg on a 386 */
 107 #endif
 108 #if defined(__sparc__) && !defined(__sparc_v9__)
 109 if(1)
 110 return0;/* No cmpxchg before v9 sparc. */
 111 #endif
 112 return1;
 113 }