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 
17 void 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 
25 struct 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 
48 void 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 
63 int 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 
101 int 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 
123 int 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 
153