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 =
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
37void host1x_channel_list_free(struct host1x_channel_list *chlist)
38{
39	kfree(chlist->allocated_channels);
40	kfree(chlist->channels);
41}
42
43int 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}
49EXPORT_SYMBOL(host1x_job_submit);
50
51struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
52{
53	kref_get(&channel->refcount);
54
55	return channel;
56}
57EXPORT_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 */
67struct 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
78static void release_channel(struct kref *kref)
79{
80	struct host1x_channel *channel =
81		container_of(kref, struct host1x_channel, refcount);
82	struct host1x *host = dev_get_drvdata(channel->dev->parent);
83	struct host1x_channel_list *chlist = &host->channel_list;
84
85	host1x_hw_cdma_stop(host, &channel->cdma);
86	host1x_cdma_deinit(&channel->cdma);
87
88	clear_bit(channel->id, chlist->allocated_channels);
89}
90
91void host1x_channel_put(struct host1x_channel *channel)
92{
93	kref_put(&channel->refcount, release_channel);
94}
95EXPORT_SYMBOL(host1x_channel_put);
96
97static struct host1x_channel *acquire_unused_channel(struct host1x *host)
98{
99	struct host1x_channel_list *chlist = &host->channel_list;
100	unsigned int max_channels = host->info->nb_channels;
101	unsigned int index;
102
103	index = find_first_zero_bit(chlist->allocated_channels, max_channels);
104	if (index >= max_channels) {
105		dev_err(host->dev, "failed to find free channel\n");
106		return NULL;
107	}
108
109	chlist->channels[index].id = index;
110
111	set_bit(index, chlist->allocated_channels);
112
113	return &chlist->channels[index];
114}
115
116/**
117 * host1x_channel_request() - Allocate a channel
118 * @client: Host1x client this channel will be used to send commands to
119 *
120 * Allocates a new host1x channel for @client. May return NULL if CDMA
121 * initialization fails.
122 */
123struct host1x_channel *host1x_channel_request(struct host1x_client *client)
124{
125	struct host1x *host = dev_get_drvdata(client->dev->parent);
126	struct host1x_channel_list *chlist = &host->channel_list;
127	struct host1x_channel *channel;
128	int err;
129
130	channel = acquire_unused_channel(host);
131	if (!channel)
132		return NULL;
133
134	kref_init(&channel->refcount);
135	mutex_init(&channel->submitlock);
136	channel->client = client;
137	channel->dev = client->dev;
138
139	err = host1x_hw_channel_init(host, channel, channel->id);
140	if (err < 0)
141		goto fail;
142
143	err = host1x_cdma_init(&channel->cdma);
144	if (err < 0)
145		goto fail;
146
147	return channel;
148
149fail:
150	clear_bit(channel->id, chlist->allocated_channels);
151
152	dev_err(client->dev, "failed to initialize channel\n");
153
154	return NULL;
155}
156EXPORT_SYMBOL(host1x_channel_request);
157