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 */
16int 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
35void host1x_channel_list_free(struct host1x_channel_list *chlist)
36{
37	bitmap_free(chlist->allocated_channels);
38	kfree(chlist->channels);
39}
40
41int 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}
47EXPORT_SYMBOL(host1x_job_submit);
48
49struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
50{
51	kref_get(&channel->refcount);
52
53	return channel;
54}
55EXPORT_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 */
65struct 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
76void 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}
82EXPORT_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 */
90void 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
103static 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
116void host1x_channel_put(struct host1x_channel *channel)
117{
118	kref_put(&channel->refcount, release_channel);
119}
120EXPORT_SYMBOL(host1x_channel_put);
121
122static 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 */
153struct 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
179fail:
180	clear_bit(channel->id, chlist->allocated_channels);
181
182	dev_err(client->dev, "failed to initialize channel\n");
183
184	return NULL;
185}
186EXPORT_SYMBOL(host1x_channel_request);
187