drm: move drm_can_sleep() to drm_util.h

Move drm_can_sleep() out of drmP.h to allow users
to get rid of the drmP.h include.

There was no header file that was a good match for this helper function.
So add this to drm_util with the relevant includes.

Add include of drm_util.h to all users.

v2:
- Update comments to use kernel-doc style (Daniel)
- Add FIXME to drm_can_sleep and add note that this
  function should not be used in new code (Daniel)

v3:
- Fix kernel-doc syntax (Daniel)
- Plug drm_util.h into drm-internels.rst (Daniel)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190112193251.20450-2-sam@ravnborg.org

1 files changed, 42 insertions, 1 deletions

diff --git a/include/drm/drm_util.h b/include/drm/drm_util.h
index 88abdca89baa..f776a55e5508 100644
--- a/include/drm/drm_util.h
+++ b/include/drm/drm_util.h
@@ -26,7 +26,48 @@
 #ifndef _DRM_UTIL_H_
 #define _DRM_UTIL_H_
 
-/* helper for handling conditionals in various for_each macros */
+/**
+ * DOC: drm utils
+ *
+ * Macros and inline functions that does not naturally belong in other places
+ */
+
+#include <linux/irqflags.h>
+#include <linux/preempt.h>
+#include <linux/kgdb.h>
+#include <linux/smp.h>
+
+/**
+ * for_each_if - helper for handling conditionals in various for_each macros
+ * @condition: The condition to check
+ *
+ * Typical use::
+ *
+ *	#define for_each_foo_bar(x, y) \'
+ *		list_for_each_entry(x, y->list, head) \'
+ *			for_each_if(x->something == SOMETHING)
+ *
+ * The for_each_if() macro makes the use of for_each_foo_bar() less error
+ * prone.
+ */
 #define for_each_if(condition) if (!(condition)) {} else
 
+/**
+ * drm_can_sleep - returns true if currently okay to sleep
+ *
+ * This function shall not be used in new code.
+ * The check for running in atomic context may not work - see linux/preempt.h.
+ *
+ * FIXME: All users of drm_can_sleep should be removed (see todo.rst)
+ *
+ * Returns:
+ * True if kgdb is active or we are in an atomic context or irqs are disabled
+ */
+static inline bool drm_can_sleep(void)
+{
+	if (in_atomic() || in_dbg_master() || irqs_disabled())
+		return false;
+	return true;
+}
+
 #endif