drm/nouveau/core: basic event interface between core and drm

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/Makefile

@@ -11,6 +11,7 @@ nouveau-y := core/core/client.o
 nouveau-y += core/core/engctx.o
 nouveau-y += core/core/engine.o
 nouveau-y += core/core/enum.o
+nouveau-y += core/core/event.o
 nouveau-y += core/core/falcon.o
 nouveau-y += core/core/gpuobj.o
 nouveau-y += core/core/handle.o

drivers/gpu/drm/nouveau/core/core/event.c

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <core/os.h>
+#include <core/event.h>
+
+static void
+nouveau_event_put_locked(struct nouveau_event *event, int index,
+			 struct nouveau_eventh *handler)
+{
+	if (!--event->index[index].refs)
+		event->disable(event, index);
+	list_del(&handler->head);
+}
+
+void
+nouveau_event_put(struct nouveau_event *event, int index,
+		  struct nouveau_eventh *handler)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&event->lock, flags);
+	if (index < event->index_nr)
+		nouveau_event_put_locked(event, index, handler);
+	spin_unlock_irqrestore(&event->lock, flags);
+}
+
+void
+nouveau_event_get(struct nouveau_event *event, int index,
+		  struct nouveau_eventh *handler)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&event->lock, flags);
+	if (index < event->index_nr) {
+		list_add(&handler->head, &event->index[index].list);
+		if (!event->index[index].refs++)
+			event->enable(event, index);
+	}
+	spin_unlock_irqrestore(&event->lock, flags);
+}
+
+void
+nouveau_event_trigger(struct nouveau_event *event, int index)
+{
+	struct nouveau_eventh *handler, *temp;
+	unsigned long flags;
+
+	if (index >= event->index_nr)
+		return;
+
+	spin_lock_irqsave(&event->lock, flags);
+	list_for_each_entry_safe(handler, temp, &event->index[index].list, head) {
+		if (handler->func(handler, index) == NVKM_EVENT_DROP) {
+			nouveau_event_put_locked(event, index, handler);
+		}
+	}
+	spin_unlock_irqrestore(&event->lock, flags);
+}
+
+void
+nouveau_event_destroy(struct nouveau_event **pevent)
+{
+	struct nouveau_event *event = *pevent;
+	if (event) {
+		kfree(event);
+		*pevent = NULL;
+	}
+}
+
+int
+nouveau_event_create(int index_nr, struct nouveau_event **pevent)
+{
+	struct nouveau_event *event;
+	int i;
+
+	event = *pevent = kzalloc(sizeof(*event) + index_nr *
+				  sizeof(event->index[0]), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
+
+	spin_lock_init(&event->lock);
+	for (i = 0; i < index_nr; i++)
+		INIT_LIST_HEAD(&event->index[i].list);
+	event->index_nr = index_nr;
+	return 0;
+}

drivers/gpu/drm/nouveau/core/include/core/event.h

@@ -0,0 +1,36 @@
+#ifndef __NVKM_EVENT_H__
+#define __NVKM_EVENT_H__
+
+/* return codes from event handlers */
+#define NVKM_EVENT_DROP 0
+#define NVKM_EVENT_KEEP 1
+
+struct nouveau_eventh {
+	struct list_head head;
+	int (*func)(struct nouveau_eventh *, int index);
+};
+
+struct nouveau_event {
+	spinlock_t lock;
+
+	void *priv;
+	void (*enable)(struct nouveau_event *, int index);
+	void (*disable)(struct nouveau_event *, int index);
+
+	int index_nr;
+	struct {
+		struct list_head list;
+		int refs;
+	} index[];
+};
+
+int  nouveau_event_create(int index_nr, struct nouveau_event **);
+void nouveau_event_destroy(struct nouveau_event **);
+void nouveau_event_trigger(struct nouveau_event *, int index);
+
+void nouveau_event_get(struct nouveau_event *, int index,
+		       struct nouveau_eventh *);
+void nouveau_event_put(struct nouveau_event *, int index,
+		       struct nouveau_eventh *);
+
+#endif