1/*
  2 * Copyright 2014 Red Hat Inc.
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice shall be included in
 12 * all copies or substantial portions of the Software.
 13 *
 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 20 * OTHER DEALINGS IN THE SOFTWARE.
 21 *
 22 * Authors: Ben Skeggs <bskeggs@redhat.com>
 23 */
 24#include <core/notify.h>
 25#include <core/event.h>
 26
 27static inline void
 28nvkm_notify_put_locked(struct nvkm_notify *notify)
 29{
 30	if (notify->block++ == 0)
 31		nvkm_event_put(notify->event, notify->types, notify->index);
 32}
 33
 34void
 35nvkm_notify_put(struct nvkm_notify *notify)
 36{
 37	struct nvkm_event *event = notify->event;
 38	unsigned long flags;
 39	if (likely(event) &&
 40	    test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
 41		spin_lock_irqsave(&event->refs_lock, flags);
 42		nvkm_notify_put_locked(notify);
 43		spin_unlock_irqrestore(&event->refs_lock, flags);
 44		if (test_bit(NVKM_NOTIFY_WORK, &notify->flags))
 45			flush_work(&notify->work);
 46	}
 47}
 48
 49static inline void
 50nvkm_notify_get_locked(struct nvkm_notify *notify)
 51{
 52	if (--notify->block == 0)
 53		nvkm_event_get(notify->event, notify->types, notify->index);
 54}
 55
 56void
 57nvkm_notify_get(struct nvkm_notify *notify)
 58{
 59	struct nvkm_event *event = notify->event;
 60	unsigned long flags;
 61	if (likely(event) &&
 62	    !test_and_set_bit(NVKM_NOTIFY_USER, &notify->flags)) {
 63		spin_lock_irqsave(&event->refs_lock, flags);
 64		nvkm_notify_get_locked(notify);
 65		spin_unlock_irqrestore(&event->refs_lock, flags);
 66	}
 67}
 68
 69static inline void
 70nvkm_notify_func(struct nvkm_notify *notify)
 71{
 72	struct nvkm_event *event = notify->event;
 73	int ret = notify->func(notify);
 74	unsigned long flags;
 75	if ((ret == NVKM_NOTIFY_KEEP) ||
 76	    !test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
 77		spin_lock_irqsave(&event->refs_lock, flags);
 78		nvkm_notify_get_locked(notify);
 79		spin_unlock_irqrestore(&event->refs_lock, flags);
 80	}
 81}
 82
 83static void
 84nvkm_notify_work(struct work_struct *work)
 85{
 86	struct nvkm_notify *notify = container_of(work, typeof(*notify), work);
 87	nvkm_notify_func(notify);
 88}
 89
 90void
 91nvkm_notify_send(struct nvkm_notify *notify, void *data, u32 size)
 92{
 93	struct nvkm_event *event = notify->event;
 94	unsigned long flags;
 95
 96	assert_spin_locked(&event->list_lock);
 97	BUG_ON(size != notify->size);
 98
 99	spin_lock_irqsave(&event->refs_lock, flags);
100	if (notify->block) {
101		spin_unlock_irqrestore(&event->refs_lock, flags);
102		return;
103	}
104	nvkm_notify_put_locked(notify);
105	spin_unlock_irqrestore(&event->refs_lock, flags);
106
107	if (test_bit(NVKM_NOTIFY_WORK, &notify->flags)) {
108		memcpy((void *)notify->data, data, size);
109		schedule_work(&notify->work);
110	} else {
111		notify->data = data;
112		nvkm_notify_func(notify);
113		notify->data = NULL;
114	}
115}
116
117void
118nvkm_notify_fini(struct nvkm_notify *notify)
119{
120	unsigned long flags;
121	if (notify->event) {
122		nvkm_notify_put(notify);
123		spin_lock_irqsave(&notify->event->list_lock, flags);
124		list_del(&notify->head);
125		spin_unlock_irqrestore(&notify->event->list_lock, flags);
126		kfree((void *)notify->data);
127		notify->event = NULL;
128	}
129}
130
131int
132nvkm_notify_init(struct nvkm_object *object, struct nvkm_event *event,
133		 int (*func)(struct nvkm_notify *), bool work,
134		 void *data, u32 size, u32 reply,
135		 struct nvkm_notify *notify)
136{
137	unsigned long flags;
138	int ret = -ENODEV;
139	if ((notify->event = event), event->refs) {
140		ret = event->func->ctor(object, data, size, notify);
141		if (ret == 0 && (ret = -EINVAL, notify->size == reply)) {
142			notify->flags = 0;
143			notify->block = 1;
144			notify->func = func;
145			notify->data = NULL;
146			if (ret = 0, work) {
147				INIT_WORK(&notify->work, nvkm_notify_work);
148				set_bit(NVKM_NOTIFY_WORK, &notify->flags);
149				notify->data = kmalloc(reply, GFP_KERNEL);
150				if (!notify->data)
151					ret = -ENOMEM;
152			}
153		}
154		if (ret == 0) {
155			spin_lock_irqsave(&event->list_lock, flags);
156			list_add_tail(&notify->head, &event->list);
157			spin_unlock_irqrestore(&event->list_lock, flags);
158		}
159	}
160	if (ret)
161		notify->event = NULL;
162	return ret;
163}