LXR linux/include/drm/drm

   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
  40/*
  41 * Use EXPORT_SYMBOL_FOR_TESTS_ONLY() for functions that shall
  42 * only be visible for drmselftests.
  43 */
  44#if defined(CONFIG_DRM_DEBUG_SELFTEST_MODULE)
  45#define EXPORT_SYMBOL_FOR_TESTS_ONLY(x) EXPORT_SYMBOL(x)
  46#else
  47#define EXPORT_SYMBOL_FOR_TESTS_ONLY(x)
  48#endif
  49
  50/**
  51 * for_each_if - helper for handling conditionals in various for_each macros
  52 * @condition: The condition to check
  53 *
  54 * Typical use::
  55 *
  56 *      #define for_each_foo_bar(x, y) \'
  57 *              list_for_each_entry(x, y->list, head) \'
  58 *                      for_each_if(x->something == SOMETHING)
  59 *
  60 * The for_each_if() macro makes the use of for_each_foo_bar() less error
  61 * prone.
  62 */
  63#define for_each_if(condition) if (!(condition)) {} else
  64
  65/**
  66 * drm_can_sleep - returns true if currently okay to sleep
  67 *
  68 * This function shall not be used in new code.
  69 * The check for running in atomic context may not work - see linux/preempt.h.
  70 *
  71 * FIXME: All users of drm_can_sleep should be removed (see todo.rst)
  72 *
  73 * Returns:
  74 * False if kgdb is active, we are in atomic context or irqs are disabled.
  75 */
  76static inline bool drm_can_sleep(void)
  77{
  78        if (in_atomic() || in_dbg_master() || irqs_disabled())
  79                return false;
  80        return true;
  81}
  82
  83#endif
  84