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 =
25 kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
26 GFP_KERNEL);
27 if (!chlist->allocated_channels) {
28 kfree(chlist->channels);
29 return -ENOMEM;
30 }
31
32 bitmap_zero(chlist->allocated_channels, num_channels);
33
34 return 0;
35 }
36
host1x_channel_list_free(struct host1x_channel_list * chlist)37 void host1x_channel_list_free(struct host1x_channel_list *chlist)
38 {
39 kfree(chlist->allocated_channels);
40 kfree(chlist->channels);
41 }
42
host1x_job_submit(struct host1x_job * job)43 int host1x_job_submit(struct host1x_job *job)
44 {
45 struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
46
47 return host1x_hw_channel_submit(host, job);
48 }
49 EXPORT_SYMBOL(host1x_job_submit);
50
host1x_channel_get(struct host1x_channel * channel)51 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
52 {
53 kref_get(&channel->refcount);
54
55 return channel;
56 }
57 EXPORT_SYMBOL(host1x_channel_get);
58
59 /**
60 * host1x_channel_get_index() - Attempt to get channel reference by index
61 * @host: Host1x device object
62 * @index: Index of channel
63 *
64 * If channel number @index is currently allocated, increase its refcount
65 * and return a pointer to it. Otherwise, return NULL.
66 */
host1x_channel_get_index(struct host1x * host,unsigned int index)67 struct host1x_channel *host1x_channel_get_index(struct host1x *host,
68 unsigned int index)
69 {
70 struct host1x_channel *ch = &host->channel_list.channels[index];
71
72 if (!kref_get_unless_zero(&ch->refcount))
73 return NULL;
74
75 return ch;
76 }
77
host1x_channel_stop(struct host1x_channel * channel)78 void host1x_channel_stop(struct host1x_channel *channel)
79 {
80 struct host1x *host = dev_get_drvdata(channel->dev->parent);
81
82 host1x_hw_cdma_stop(host, &channel->cdma);
83 }
84 EXPORT_SYMBOL(host1x_channel_stop);
85
release_channel(struct kref * kref)86 static void release_channel(struct kref *kref)
87 {
88 struct host1x_channel *channel =
89 container_of(kref, struct host1x_channel, refcount);
90 struct host1x *host = dev_get_drvdata(channel->dev->parent);
91 struct host1x_channel_list *chlist = &host->channel_list;
92
93 host1x_hw_cdma_stop(host, &channel->cdma);
94 host1x_cdma_deinit(&channel->cdma);
95
96 clear_bit(channel->id, chlist->allocated_channels);
97 }
98
host1x_channel_put(struct host1x_channel * channel)99 void host1x_channel_put(struct host1x_channel *channel)
100 {
101 kref_put(&channel->refcount, release_channel);
102 }
103 EXPORT_SYMBOL(host1x_channel_put);
104
acquire_unused_channel(struct host1x * host)105 static struct host1x_channel *acquire_unused_channel(struct host1x *host)
106 {
107 struct host1x_channel_list *chlist = &host->channel_list;
108 unsigned int max_channels = host->info->nb_channels;
109 unsigned int index;
110
111 index = find_first_zero_bit(chlist->allocated_channels, max_channels);
112 if (index >= max_channels) {
113 dev_err(host->dev, "failed to find free channel\n");
114 return NULL;
115 }
116
117 chlist->channels[index].id = index;
118
119 set_bit(index, chlist->allocated_channels);
120
121 return &chlist->channels[index];
122 }
123
124 /**
125 * host1x_channel_request() - Allocate a channel
126 * @client: Host1x client this channel will be used to send commands to
127 *
128 * Allocates a new host1x channel for @client. May return NULL if CDMA
129 * initialization fails.
130 */
host1x_channel_request(struct host1x_client * client)131 struct host1x_channel *host1x_channel_request(struct host1x_client *client)
132 {
133 struct host1x *host = dev_get_drvdata(client->dev->parent);
134 struct host1x_channel_list *chlist = &host->channel_list;
135 struct host1x_channel *channel;
136 int err;
137
138 channel = acquire_unused_channel(host);
139 if (!channel)
140 return NULL;
141
142 kref_init(&channel->refcount);
143 mutex_init(&channel->submitlock);
144 channel->client = client;
145 channel->dev = client->dev;
146
147 err = host1x_hw_channel_init(host, channel, channel->id);
148 if (err < 0)
149 goto fail;
150
151 err = host1x_cdma_init(&channel->cdma);
152 if (err < 0)
153 goto fail;
154
155 return channel;
156
157 fail:
158 clear_bit(channel->id, chlist->allocated_channels);
159
160 dev_err(client->dev, "failed to initialize channel\n");
161
162 return NULL;
163 }
164 EXPORT_SYMBOL(host1x_channel_request);
165