xref: /openbmc/linux/drivers/gpu/host1x/channel.c (revision 8730046c)
1 /*
2  * Tegra host1x Channel
3  *
4  * Copyright (c) 2010-2013, NVIDIA Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 
22 #include "channel.h"
23 #include "dev.h"
24 #include "job.h"
25 
26 /* Constructor for the host1x device list */
27 int host1x_channel_list_init(struct host1x *host)
28 {
29 	INIT_LIST_HEAD(&host->chlist.list);
30 	mutex_init(&host->chlist_mutex);
31 
32 	if (host->info->nb_channels > BITS_PER_LONG) {
33 		WARN(1, "host1x hardware has more channels than supported by the driver\n");
34 		return -ENOSYS;
35 	}
36 
37 	return 0;
38 }
39 
40 int host1x_job_submit(struct host1x_job *job)
41 {
42 	struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
43 
44 	return host1x_hw_channel_submit(host, job);
45 }
46 EXPORT_SYMBOL(host1x_job_submit);
47 
48 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
49 {
50 	int err = 0;
51 
52 	mutex_lock(&channel->reflock);
53 
54 	if (channel->refcount == 0)
55 		err = host1x_cdma_init(&channel->cdma);
56 
57 	if (!err)
58 		channel->refcount++;
59 
60 	mutex_unlock(&channel->reflock);
61 
62 	return err ? NULL : channel;
63 }
64 EXPORT_SYMBOL(host1x_channel_get);
65 
66 void host1x_channel_put(struct host1x_channel *channel)
67 {
68 	mutex_lock(&channel->reflock);
69 
70 	if (channel->refcount == 1) {
71 		struct host1x *host = dev_get_drvdata(channel->dev->parent);
72 
73 		host1x_hw_cdma_stop(host, &channel->cdma);
74 		host1x_cdma_deinit(&channel->cdma);
75 	}
76 
77 	channel->refcount--;
78 
79 	mutex_unlock(&channel->reflock);
80 }
81 EXPORT_SYMBOL(host1x_channel_put);
82 
83 struct host1x_channel *host1x_channel_request(struct device *dev)
84 {
85 	struct host1x *host = dev_get_drvdata(dev->parent);
86 	unsigned int max_channels = host->info->nb_channels;
87 	struct host1x_channel *channel = NULL;
88 	unsigned long index;
89 	int err;
90 
91 	mutex_lock(&host->chlist_mutex);
92 
93 	index = find_first_zero_bit(&host->allocated_channels, max_channels);
94 	if (index >= max_channels)
95 		goto fail;
96 
97 	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
98 	if (!channel)
99 		goto fail;
100 
101 	err = host1x_hw_channel_init(host, channel, index);
102 	if (err < 0)
103 		goto fail;
104 
105 	/* Link device to host1x_channel */
106 	channel->dev = dev;
107 
108 	/* Add to channel list */
109 	list_add_tail(&channel->list, &host->chlist.list);
110 
111 	host->allocated_channels |= BIT(index);
112 
113 	mutex_unlock(&host->chlist_mutex);
114 	return channel;
115 
116 fail:
117 	dev_err(dev, "failed to init channel\n");
118 	kfree(channel);
119 	mutex_unlock(&host->chlist_mutex);
120 	return NULL;
121 }
122 EXPORT_SYMBOL(host1x_channel_request);
123 
124 void host1x_channel_free(struct host1x_channel *channel)
125 {
126 	struct host1x *host = dev_get_drvdata(channel->dev->parent);
127 
128 	host->allocated_channels &= ~BIT(channel->id);
129 	list_del(&channel->list);
130 	kfree(channel);
131 }
132 EXPORT_SYMBOL(host1x_channel_free);
133