chid.c

  1/*
  2 * Copyright 2020 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#include "chid.h"
 23
 24void
 25nvkm_chid_put(struct nvkm_chid *chid, int id, spinlock_t *data_lock)
 26{
 27	if (id >= 0) {
 28		spin_lock_irq(&chid->lock);
 29		spin_lock(data_lock);
 30		chid->data[id] = NULL;
 31		spin_unlock(data_lock);
 32		clear_bit(id, chid->used);
 33		spin_unlock_irq(&chid->lock);
 34	}
 35}
 36
 37int
 38nvkm_chid_get(struct nvkm_chid *chid, void *data)
 39{
 40	int id = -1, cid;
 41
 42	spin_lock_irq(&chid->lock);
 43	cid = find_first_zero_bit(chid->used, chid->nr);
 44	if (cid < chid->nr) {
 45		set_bit(cid, chid->used);
 46		chid->data[cid] = data;
 47		id = cid;
 48	}
 49	spin_unlock_irq(&chid->lock);
 50	return id;
 51}
 52
 53static void
 54nvkm_chid_del(struct kref *kref)
 55{
 56	struct nvkm_chid *chid = container_of(kref, typeof(*chid), kref);
 57
 58	nvkm_event_fini(&chid->event);
 59
 60	kvfree(chid->data);
 61	kfree(chid);
 62}
 63
 64void
 65nvkm_chid_unref(struct nvkm_chid **pchid)
 66{
 67	struct nvkm_chid *chid = *pchid;
 68
 69	if (!chid)
 70		return;
 71
 72	kref_put(&chid->kref, nvkm_chid_del);
 73	*pchid = NULL;
 74}
 75
 76struct nvkm_chid *
 77nvkm_chid_ref(struct nvkm_chid *chid)
 78{
 79	if (chid)
 80		kref_get(&chid->kref);
 81
 82	return chid;
 83}
 84
 85int
 86nvkm_chid_new(const struct nvkm_event_func *func, struct nvkm_subdev *subdev,
 87	      int nr, int first, int count, struct nvkm_chid **pchid)
 88{
 89	struct nvkm_chid *chid;
 90	int id;
 91
 92	if (!(chid = *pchid = kzalloc(struct_size(chid, used, nr), GFP_KERNEL)))
 93		return -ENOMEM;
 94
 95	kref_init(&chid->kref);
 96	chid->nr = nr;
 97	chid->mask = chid->nr - 1;
 98	spin_lock_init(&chid->lock);
 99
100	if (!(chid->data = kvzalloc(sizeof(*chid->data) * nr, GFP_KERNEL))) {
101		nvkm_chid_unref(pchid);
102		return -ENOMEM;
103	}
104
105	for (id = 0; id < first; id++)
106		__set_bit(id, chid->used);
107	for (id = first + count; id < nr; id++)
108		__set_bit(id, chid->used);
109
110	return nvkm_event_init(func, subdev, 1, nr, &chid->event);
111}