1/* Copyright (c) 2017 The Linux Foundation. All rights reserved.
  2 *
  3 * This program is free software; you can redistribute it and/or modify
  4 * it under the terms of the GNU General Public License version 2 and
  5 * only version 2 as published by the Free Software Foundation.
  6 *
  7 * This program is distributed in the hope that it will be useful,
  8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 10 * GNU General Public License for more details.
 11 *
 12 */
 13
 14#include <linux/kref.h>
 15#include "msm_gpu.h"
 16
 17void msm_submitqueue_destroy(struct kref *kref)
 18{
 19	struct msm_gpu_submitqueue *queue = container_of(kref,
 20		struct msm_gpu_submitqueue, ref);
 21
 22	kfree(queue);
 23}
 24
 25struct msm_gpu_submitqueue *msm_submitqueue_get(struct msm_file_private *ctx,
 26		u32 id)
 27{
 28	struct msm_gpu_submitqueue *entry;
 29
 30	if (!ctx)
 31		return NULL;
 32
 33	read_lock(&ctx->queuelock);
 34
 35	list_for_each_entry(entry, &ctx->submitqueues, node) {
 36		if (entry->id == id) {
 37			kref_get(&entry->ref);
 38			read_unlock(&ctx->queuelock);
 39
 40			return entry;
 41		}
 42	}
 43
 44	read_unlock(&ctx->queuelock);
 45	return NULL;
 46}
 47
 48void msm_submitqueue_close(struct msm_file_private *ctx)
 49{
 50	struct msm_gpu_submitqueue *entry, *tmp;
 51
 52	if (!ctx)
 53		return;
 54
 55	/*
 56	 * No lock needed in close and there won't
 57	 * be any more user ioctls coming our way
 58	 */
 59	list_for_each_entry_safe(entry, tmp, &ctx->submitqueues, node)
 60		msm_submitqueue_put(entry);
 61}
 62
 63int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 64		u32 prio, u32 flags, u32 *id)
 65{
 66	struct msm_drm_private *priv = drm->dev_private;
 67	struct msm_gpu_submitqueue *queue;
 68
 69	if (!ctx)
 70		return -ENODEV;
 71
 72	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 73
 74	if (!queue)
 75		return -ENOMEM;
 76
 77	kref_init(&queue->ref);
 78	queue->flags = flags;
 79
 80	if (priv->gpu) {
 81		if (prio >= priv->gpu->nr_rings)
 82			return -EINVAL;
 83
 84		queue->prio = prio;
 85	}
 86
 87	write_lock(&ctx->queuelock);
 88
 89	queue->id = ctx->queueid++;
 90
 91	if (id)
 92		*id = queue->id;
 93
 94	list_add_tail(&queue->node, &ctx->submitqueues);
 95
 96	write_unlock(&ctx->queuelock);
 97
 98	return 0;
 99}
100
101int msm_submitqueue_init(struct drm_device *drm, struct msm_file_private *ctx)
102{
103	struct msm_drm_private *priv = drm->dev_private;
104	int default_prio;
105
106	if (!ctx)
107		return 0;
108
109	/*
110	 * Select priority 2 as the "default priority" unless nr_rings is less
111	 * than 2 and then pick the lowest pirority
112	 */
113	default_prio = priv->gpu ?
114		clamp_t(uint32_t, 2, 0, priv->gpu->nr_rings - 1) : 0;
115
116	INIT_LIST_HEAD(&ctx->submitqueues);
117
118	rwlock_init(&ctx->queuelock);
119
120	return msm_submitqueue_create(drm, ctx, default_prio, 0, NULL);
121}
122
123int msm_submitqueue_remove(struct msm_file_private *ctx, u32 id)
124{
125	struct msm_gpu_submitqueue *entry;
126
127	if (!ctx)
128		return 0;
129
130	/*
131	 * id 0 is the "default" queue and can't be destroyed
132	 * by the user
133	 */
134	if (!id)
135		return -ENOENT;
136
137	write_lock(&ctx->queuelock);
138
139	list_for_each_entry(entry, &ctx->submitqueues, node) {
140		if (entry->id == id) {
141			list_del(&entry->node);
142			write_unlock(&ctx->queuelock);
143
144			msm_submitqueue_put(entry);
145			return 0;
146		}
147	}
148
149	write_unlock(&ctx->queuelock);
150	return -ENOENT;
151}
152