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 */
host1x_channel_list_init(struct host1x_channel_list * chlist,unsigned int num_channels)27 int host1x_channel_list_init(struct host1x_channel_list *chlist,
28 unsigned int num_channels)
29 {
30 chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
31 GFP_KERNEL);
32 if (!chlist->channels)
33 return -ENOMEM;
34
35 chlist->allocated_channels =
36 kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
37 GFP_KERNEL);
38 if (!chlist->allocated_channels) {
39 kfree(chlist->channels);
40 return -ENOMEM;
41 }
42
43 bitmap_zero(chlist->allocated_channels, num_channels);
44
45 return 0;
46 }
47
host1x_channel_list_free(struct host1x_channel_list * chlist)48 void host1x_channel_list_free(struct host1x_channel_list *chlist)
49 {
50 kfree(chlist->allocated_channels);
51 kfree(chlist->channels);
52 }
53
host1x_job_submit(struct host1x_job * job)54 int host1x_job_submit(struct host1x_job *job)
55 {
56 struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
57
58 return host1x_hw_channel_submit(host, job);
59 }
60 EXPORT_SYMBOL(host1x_job_submit);
61
host1x_channel_get(struct host1x_channel * channel)62 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
63 {
64 kref_get(&channel->refcount);
65
66 return channel;
67 }
68 EXPORT_SYMBOL(host1x_channel_get);
69
70 /**
71 * host1x_channel_get_index() - Attempt to get channel reference by index
72 * @host: Host1x device object
73 * @index: Index of channel
74 *
75 * If channel number @index is currently allocated, increase its refcount
76 * and return a pointer to it. Otherwise, return NULL.
77 */
host1x_channel_get_index(struct host1x * host,unsigned int index)78 struct host1x_channel *host1x_channel_get_index(struct host1x *host,
79 unsigned int index)
80 {
81 struct host1x_channel *ch = &host->channel_list.channels[index];
82
83 if (!kref_get_unless_zero(&ch->refcount))
84 return NULL;
85
86 return ch;
87 }
88
release_channel(struct kref * kref)89 static void release_channel(struct kref *kref)
90 {
91 struct host1x_channel *channel =
92 container_of(kref, struct host1x_channel, refcount);
93 struct host1x *host = dev_get_drvdata(channel->dev->parent);
94 struct host1x_channel_list *chlist = &host->channel_list;
95
96 host1x_hw_cdma_stop(host, &channel->cdma);
97 host1x_cdma_deinit(&channel->cdma);
98
99 clear_bit(channel->id, chlist->allocated_channels);
100 }
101
host1x_channel_put(struct host1x_channel * channel)102 void host1x_channel_put(struct host1x_channel *channel)
103 {
104 kref_put(&channel->refcount, release_channel);
105 }
106 EXPORT_SYMBOL(host1x_channel_put);
107
acquire_unused_channel(struct host1x * host)108 static struct host1x_channel *acquire_unused_channel(struct host1x *host)
109 {
110 struct host1x_channel_list *chlist = &host->channel_list;
111 unsigned int max_channels = host->info->nb_channels;
112 unsigned int index;
113
114 index = find_first_zero_bit(chlist->allocated_channels, max_channels);
115 if (index >= max_channels) {
116 dev_err(host->dev, "failed to find free channel\n");
117 return NULL;
118 }
119
120 chlist->channels[index].id = index;
121
122 set_bit(index, chlist->allocated_channels);
123
124 return &chlist->channels[index];
125 }
126
127 /**
128 * host1x_channel_request() - Allocate a channel
129 * @device: Host1x unit this channel will be used to send commands to
130 *
131 * Allocates a new host1x channel for @device. May return NULL if CDMA
132 * initialization fails.
133 */
host1x_channel_request(struct device * dev)134 struct host1x_channel *host1x_channel_request(struct device *dev)
135 {
136 struct host1x *host = dev_get_drvdata(dev->parent);
137 struct host1x_channel_list *chlist = &host->channel_list;
138 struct host1x_channel *channel;
139 int err;
140
141 channel = acquire_unused_channel(host);
142 if (!channel)
143 return NULL;
144
145 kref_init(&channel->refcount);
146 mutex_init(&channel->submitlock);
147 channel->dev = dev;
148
149 err = host1x_hw_channel_init(host, channel, channel->id);
150 if (err < 0)
151 goto fail;
152
153 err = host1x_cdma_init(&channel->cdma);
154 if (err < 0)
155 goto fail;
156
157 return channel;
158
159 fail:
160 clear_bit(channel->id, chlist->allocated_channels);
161
162 dev_err(dev, "failed to initialize channel\n");
163
164 return NULL;
165 }
166 EXPORT_SYMBOL(host1x_channel_request);
167
