linux-sg2042/drivers/gpu/host1x/channel.c

167 lines
4.2 KiB
C

/*
* Tegra host1x Channel
*
* Copyright (c) 2010-2013, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include "channel.h"
#include "dev.h"
#include "job.h"
/* Constructor for the host1x device list */
int host1x_channel_list_init(struct host1x_channel_list *chlist,
unsigned int num_channels)
{
chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
GFP_KERNEL);
if (!chlist->channels)
return -ENOMEM;
chlist->allocated_channels =
kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
GFP_KERNEL);
if (!chlist->allocated_channels) {
kfree(chlist->channels);
return -ENOMEM;
}
bitmap_zero(chlist->allocated_channels, num_channels);
return 0;
}
void host1x_channel_list_free(struct host1x_channel_list *chlist)
{
kfree(chlist->allocated_channels);
kfree(chlist->channels);
}
int host1x_job_submit(struct host1x_job *job)
{
struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
return host1x_hw_channel_submit(host, job);
}
EXPORT_SYMBOL(host1x_job_submit);
struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
{
kref_get(&channel->refcount);
return channel;
}
EXPORT_SYMBOL(host1x_channel_get);
/**
* host1x_channel_get_index() - Attempt to get channel reference by index
* @host: Host1x device object
* @index: Index of channel
*
* If channel number @index is currently allocated, increase its refcount
* and return a pointer to it. Otherwise, return NULL.
*/
struct host1x_channel *host1x_channel_get_index(struct host1x *host,
unsigned int index)
{
struct host1x_channel *ch = &host->channel_list.channels[index];
if (!kref_get_unless_zero(&ch->refcount))
return NULL;
return ch;
}
static void release_channel(struct kref *kref)
{
struct host1x_channel *channel =
container_of(kref, struct host1x_channel, refcount);
struct host1x *host = dev_get_drvdata(channel->dev->parent);
struct host1x_channel_list *chlist = &host->channel_list;
host1x_hw_cdma_stop(host, &channel->cdma);
host1x_cdma_deinit(&channel->cdma);
clear_bit(channel->id, chlist->allocated_channels);
}
void host1x_channel_put(struct host1x_channel *channel)
{
kref_put(&channel->refcount, release_channel);
}
EXPORT_SYMBOL(host1x_channel_put);
static struct host1x_channel *acquire_unused_channel(struct host1x *host)
{
struct host1x_channel_list *chlist = &host->channel_list;
unsigned int max_channels = host->info->nb_channels;
unsigned int index;
index = find_first_zero_bit(chlist->allocated_channels, max_channels);
if (index >= max_channels) {
dev_err(host->dev, "failed to find free channel\n");
return NULL;
}
chlist->channels[index].id = index;
set_bit(index, chlist->allocated_channels);
return &chlist->channels[index];
}
/**
* host1x_channel_request() - Allocate a channel
* @device: Host1x unit this channel will be used to send commands to
*
* Allocates a new host1x channel for @device. May return NULL if CDMA
* initialization fails.
*/
struct host1x_channel *host1x_channel_request(struct device *dev)
{
struct host1x *host = dev_get_drvdata(dev->parent);
struct host1x_channel_list *chlist = &host->channel_list;
struct host1x_channel *channel;
int err;
channel = acquire_unused_channel(host);
if (!channel)
return NULL;
kref_init(&channel->refcount);
mutex_init(&channel->submitlock);
channel->dev = dev;
err = host1x_hw_channel_init(host, channel, channel->id);
if (err < 0)
goto fail;
err = host1x_cdma_init(&channel->cdma);
if (err < 0)
goto fail;
return channel;
fail:
clear_bit(channel->id, chlist->allocated_channels);
dev_err(dev, "failed to initialize channel\n");
return NULL;
}
EXPORT_SYMBOL(host1x_channel_request);