1 /*
2  * Internal Header for the Direct Rendering Manager
3  *
4  * Copyright 2018 Intel Corporation
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23  * OTHER DEALINGS IN THE SOFTWARE.
24  */
25 
26 #ifndef _DRM_UTIL_H_
27 #define _DRM_UTIL_H_
28 
29 /**
30  * DOC: drm utils
31  *
32  * Macros and inline functions that does not naturally belong in other places
33  */
34 
35 #include <linux/interrupt.h>
36 #include <linux/kgdb.h>
37 #include <linux/preempt.h>
38 #include <linux/smp.h>
39 #include <linux/util_macros.h>
40 
41 /*
42  * Use EXPORT_SYMBOL_FOR_TESTS_ONLY() for functions that shall
43  * only be visible for drmselftests.
44  */
45 #if defined(CONFIG_DRM_EXPORT_FOR_TESTS)
46 #define EXPORT_SYMBOL_FOR_TESTS_ONLY(x) EXPORT_SYMBOL(x)
47 #else
48 #define EXPORT_SYMBOL_FOR_TESTS_ONLY(x)
49 #endif
50 
51 /**
52  * drm_can_sleep - returns true if currently okay to sleep
53  *
54  * This function shall not be used in new code.
55  * The check for running in atomic context may not work - see linux/preempt.h.
56  *
57  * FIXME: All users of drm_can_sleep should be removed (see todo.rst)
58  *
59  * Returns:
60  * False if kgdb is active, we are in atomic context or irqs are disabled.
61  */
drm_can_sleep(void)62 static inline bool drm_can_sleep(void)
63 {
64 	if (in_atomic() || in_dbg_master() || irqs_disabled())
65 		return false;
66 	return true;
67 }
68 
69 #endif
70