bpf: Prevent memory disambiguation attack
[linux/fpc-iii.git] / drivers / gpu / drm / msm / msm_submitqueue.c
blob5115f75b5b7f38c5d1ce81fa5edf38525331dbf4
1 /* Copyright (c) 2017 The Linux Foundation. All rights reserved.
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.
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.
14 #include <linux/kref.h>
15 #include "msm_gpu.h"
17 void msm_submitqueue_destroy(struct kref *kref)
19 struct msm_gpu_submitqueue *queue = container_of(kref,
20 struct msm_gpu_submitqueue, ref);
22 kfree(queue);
25 struct msm_gpu_submitqueue *msm_submitqueue_get(struct msm_file_private *ctx,
26 u32 id)
28 struct msm_gpu_submitqueue *entry;
30 if (!ctx)
31 return NULL;
33 read_lock(&ctx->queuelock);
35 list_for_each_entry(entry, &ctx->submitqueues, node) {
36 if (entry->id == id) {
37 kref_get(&entry->ref);
38 read_unlock(&ctx->queuelock);
40 return entry;
44 read_unlock(&ctx->queuelock);
45 return NULL;
48 void msm_submitqueue_close(struct msm_file_private *ctx)
50 struct msm_gpu_submitqueue *entry, *tmp;
52 if (!ctx)
53 return;
56 * No lock needed in close and there won't
57 * be any more user ioctls coming our way
59 list_for_each_entry_safe(entry, tmp, &ctx->submitqueues, node)
60 msm_submitqueue_put(entry);
63 int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
64 u32 prio, u32 flags, u32 *id)
66 struct msm_drm_private *priv = drm->dev_private;
67 struct msm_gpu_submitqueue *queue;
69 if (!ctx)
70 return -ENODEV;
72 queue = kzalloc(sizeof(*queue), GFP_KERNEL);
74 if (!queue)
75 return -ENOMEM;
77 kref_init(&queue->ref);
78 queue->flags = flags;
80 if (priv->gpu) {
81 if (prio >= priv->gpu->nr_rings)
82 return -EINVAL;
84 queue->prio = prio;
87 write_lock(&ctx->queuelock);
89 queue->id = ctx->queueid++;
91 if (id)
92 *id = queue->id;
94 list_add_tail(&queue->node, &ctx->submitqueues);
96 write_unlock(&ctx->queuelock);
98 return 0;
101 int msm_submitqueue_init(struct drm_device *drm, struct msm_file_private *ctx)
103 struct msm_drm_private *priv = drm->dev_private;
104 int default_prio;
106 if (!ctx)
107 return 0;
110 * Select priority 2 as the "default priority" unless nr_rings is less
111 * than 2 and then pick the lowest pirority
113 default_prio = priv->gpu ?
114 clamp_t(uint32_t, 2, 0, priv->gpu->nr_rings - 1) : 0;
116 INIT_LIST_HEAD(&ctx->submitqueues);
118 rwlock_init(&ctx->queuelock);
120 return msm_submitqueue_create(drm, ctx, default_prio, 0, NULL);
123 int msm_submitqueue_remove(struct msm_file_private *ctx, u32 id)
125 struct msm_gpu_submitqueue *entry;
127 if (!ctx)
128 return 0;
131 * id 0 is the "default" queue and can't be destroyed
132 * by the user
134 if (!id)
135 return -ENOENT;
137 write_lock(&ctx->queuelock);
139 list_for_each_entry(entry, &ctx->submitqueues, node) {
140 if (entry->id == id) {
141 list_del(&entry->node);
142 write_unlock(&ctx->queuelock);
144 msm_submitqueue_put(entry);
145 return 0;
149 write_unlock(&ctx->queuelock);
150 return -ENOENT;