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 * @device: Host1x unit this channel will be used to send commands to
119 *
120 * Allocates a new host1x channel for @device. May return NULL if CDMA
121 * initialization fails.
122 */
123struct host1x_channel *host1x_channel_request(struct device *dev)
124{
125	struct host1x *host = dev_get_drvdata(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->dev = dev;
137
138	err = host1x_hw_channel_init(host, channel, channel->id);
139	if (err < 0)
140		goto fail;
141
142	err = host1x_cdma_init(&channel->cdma);
143	if (err < 0)
144		goto fail;
145
146	return channel;
147
148fail:
149	clear_bit(channel->id, chlist->allocated_channels);
150
151	dev_err(dev, "failed to initialize channel\n");
152
153	return NULL;
154}
155EXPORT_SYMBOL(host1x_channel_request);