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