1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Tegra host1x Channel
4 *
5 * Copyright (c) 2010-2013, NVIDIA Corporation.
6 */
7
8 #include <linux/slab.h>
9 #include <linux/module.h>
10
11 #include "channel.h"
12 #include "dev.h"
13 #include "job.h"
14
15 /* Constructor for the host1x device list */
host1x_channel_list_init(struct host1x_channel_list * chlist,unsigned int num_channels)16 int host1x_channel_list_init(struct host1x_channel_list *chlist,
17 unsigned int num_channels)
18 {
19 chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
20 GFP_KERNEL);
21 if (!chlist->channels)
22 return -ENOMEM;
23
24 chlist->allocated_channels = bitmap_zalloc(num_channels, GFP_KERNEL);
25 if (!chlist->allocated_channels) {
26 kfree(chlist->channels);
27 return -ENOMEM;
28 }
29
30 mutex_init(&chlist->lock);
31
32 return 0;
33 }
34
host1x_channel_list_free(struct host1x_channel_list * chlist)35 void host1x_channel_list_free(struct host1x_channel_list *chlist)
36 {
37 bitmap_free(chlist->allocated_channels);
38 kfree(chlist->channels);
39 }
40
host1x_job_submit(struct host1x_job * job)41 int host1x_job_submit(struct host1x_job *job)
42 {
43 struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
44
45 return host1x_hw_channel_submit(host, job);
46 }
47 EXPORT_SYMBOL(host1x_job_submit);
48
host1x_channel_get(struct host1x_channel * channel)49 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
50 {
51 kref_get(&channel->refcount);
52
53 return channel;
54 }
55 EXPORT_SYMBOL(host1x_channel_get);
56
57 /**
58 * host1x_channel_get_index() - Attempt to get channel reference by index
59 * @host: Host1x device object
60 * @index: Index of channel
61 *
62 * If channel number @index is currently allocated, increase its refcount
63 * and return a pointer to it. Otherwise, return NULL.
64 */
host1x_channel_get_index(struct host1x * host,unsigned int index)65 struct host1x_channel *host1x_channel_get_index(struct host1x *host,
66 unsigned int index)
67 {
68 struct host1x_channel *ch = &host->channel_list.channels[index];
69
70 if (!kref_get_unless_zero(&ch->refcount))
71 return NULL;
72
73 return ch;
74 }
75
host1x_channel_stop(struct host1x_channel * channel)76 void host1x_channel_stop(struct host1x_channel *channel)
77 {
78 struct host1x *host = dev_get_drvdata(channel->dev->parent);
79
80 host1x_hw_cdma_stop(host, &channel->cdma);
81 }
82 EXPORT_SYMBOL(host1x_channel_stop);
83
84 /**
85 * host1x_channel_stop_all() - disable CDMA on allocated channels
86 * @host: host1x instance
87 *
88 * Stop CDMA on allocated channels
89 */
host1x_channel_stop_all(struct host1x * host)90 void host1x_channel_stop_all(struct host1x *host)
91 {
92 struct host1x_channel_list *chlist = &host->channel_list;
93 int bit;
94
95 mutex_lock(&chlist->lock);
96
97 for_each_set_bit(bit, chlist->allocated_channels, host->info->nb_channels)
98 host1x_channel_stop(&chlist->channels[bit]);
99
100 mutex_unlock(&chlist->lock);
101 }
102
release_channel(struct kref * kref)103 static void release_channel(struct kref *kref)
104 {
105 struct host1x_channel *channel =
106 container_of(kref, struct host1x_channel, refcount);
107 struct host1x *host = dev_get_drvdata(channel->dev->parent);
108 struct host1x_channel_list *chlist = &host->channel_list;
109
110 host1x_hw_cdma_stop(host, &channel->cdma);
111 host1x_cdma_deinit(&channel->cdma);
112
113 clear_bit(channel->id, chlist->allocated_channels);
114 }
115
host1x_channel_put(struct host1x_channel * channel)116 void host1x_channel_put(struct host1x_channel *channel)
117 {
118 kref_put(&channel->refcount, release_channel);
119 }
120 EXPORT_SYMBOL(host1x_channel_put);
121
acquire_unused_channel(struct host1x * host)122 static struct host1x_channel *acquire_unused_channel(struct host1x *host)
123 {
124 struct host1x_channel_list *chlist = &host->channel_list;
125 unsigned int max_channels = host->info->nb_channels;
126 unsigned int index;
127
128 mutex_lock(&chlist->lock);
129
130 index = find_first_zero_bit(chlist->allocated_channels, max_channels);
131 if (index >= max_channels) {
132 mutex_unlock(&chlist->lock);
133 dev_err(host->dev, "failed to find free channel\n");
134 return NULL;
135 }
136
137 chlist->channels[index].id = index;
138
139 set_bit(index, chlist->allocated_channels);
140
141 mutex_unlock(&chlist->lock);
142
143 return &chlist->channels[index];
144 }
145
146 /**
147 * host1x_channel_request() - Allocate a channel
148 * @client: Host1x client this channel will be used to send commands to
149 *
150 * Allocates a new host1x channel for @client. May return NULL if CDMA
151 * initialization fails.
152 */
host1x_channel_request(struct host1x_client * client)153 struct host1x_channel *host1x_channel_request(struct host1x_client *client)
154 {
155 struct host1x *host = dev_get_drvdata(client->dev->parent);
156 struct host1x_channel_list *chlist = &host->channel_list;
157 struct host1x_channel *channel;
158 int err;
159
160 channel = acquire_unused_channel(host);
161 if (!channel)
162 return NULL;
163
164 kref_init(&channel->refcount);
165 mutex_init(&channel->submitlock);
166 channel->client = client;
167 channel->dev = client->dev;
168
169 err = host1x_hw_channel_init(host, channel, channel->id);
170 if (err < 0)
171 goto fail;
172
173 err = host1x_cdma_init(&channel->cdma);
174 if (err < 0)
175 goto fail;
176
177 return channel;
178
179 fail:
180 clear_bit(channel->id, chlist->allocated_channels);
181
182 dev_err(client->dev, "failed to initialize channel\n");
183
184 return NULL;
185 }
186 EXPORT_SYMBOL(host1x_channel_request);
187