8474b02531
This is largely a rewrite of the Host1x channel allocation code, bringing several changes: - The previous code could deadlock due to an interaction between the 'reflock' mutex and CDMA timeout handling. This gets rid of the mutex. - Support for more than 32 channels, required for Tegra186 - General refactoring, including better encapsulation of channel ownership handling into channel.c Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
168 lines
4.3 KiB
C
168 lines
4.3 KiB
C
/*
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* Tegra host1x Channel
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*
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* Copyright (c) 2010-2013, NVIDIA Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include "channel.h"
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#include "dev.h"
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#include "job.h"
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/* Constructor for the host1x device list */
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int host1x_channel_list_init(struct host1x_channel_list *chlist,
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unsigned int num_channels)
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{
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chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
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GFP_KERNEL);
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if (!chlist->channels)
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return -ENOMEM;
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chlist->allocated_channels =
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kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
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GFP_KERNEL);
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if (!chlist->allocated_channels) {
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kfree(chlist->channels);
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return -ENOMEM;
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}
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bitmap_zero(chlist->allocated_channels, num_channels);
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return 0;
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}
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void host1x_channel_list_free(struct host1x_channel_list *chlist)
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{
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kfree(chlist->allocated_channels);
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kfree(chlist->channels);
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}
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int host1x_job_submit(struct host1x_job *job)
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{
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struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
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return host1x_hw_channel_submit(host, job);
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}
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EXPORT_SYMBOL(host1x_job_submit);
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struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
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{
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kref_get(&channel->refcount);
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return channel;
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}
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EXPORT_SYMBOL(host1x_channel_get);
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/**
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* host1x_channel_get_index() - Attempt to get channel reference by index
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* @host: Host1x device object
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* @index: Index of channel
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*
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* If channel number @index is currently allocated, increase its refcount
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* and return a pointer to it. Otherwise, return NULL.
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*/
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struct host1x_channel *host1x_channel_get_index(struct host1x *host,
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unsigned int index)
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{
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struct host1x_channel *ch = &host->channel_list.channels[index];
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if (!kref_get_unless_zero(&ch->refcount))
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return NULL;
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return ch;
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}
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static void release_channel(struct kref *kref)
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{
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struct host1x_channel *channel =
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container_of(kref, struct host1x_channel, refcount);
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struct host1x *host = dev_get_drvdata(channel->dev->parent);
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struct host1x_channel_list *chlist = &host->channel_list;
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host1x_hw_cdma_stop(host, &channel->cdma);
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host1x_cdma_deinit(&channel->cdma);
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clear_bit(channel->id, chlist->allocated_channels);
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}
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void host1x_channel_put(struct host1x_channel *channel)
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{
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kref_put(&channel->refcount, release_channel);
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}
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EXPORT_SYMBOL(host1x_channel_put);
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static struct host1x_channel *acquire_unused_channel(struct host1x *host)
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{
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struct host1x_channel_list *chlist = &host->channel_list;
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unsigned int max_channels = host->info->nb_channels;
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unsigned int index;
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index = find_first_zero_bit(chlist->allocated_channels, max_channels);
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if (index >= max_channels) {
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dev_err(host->dev, "failed to find free channel\n");
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return NULL;
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}
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chlist->channels[index].id = index;
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set_bit(index, chlist->allocated_channels);
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return &chlist->channels[index];
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}
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/**
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* host1x_channel_request() - Allocate a channel
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* @device: Host1x unit this channel will be used to send commands to
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*
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* Allocates a new host1x channel for @device. If there are no free channels,
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* this will sleep until one becomes available. May return NULL if CDMA
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* initialization fails.
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*/
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struct host1x_channel *host1x_channel_request(struct device *dev)
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{
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struct host1x *host = dev_get_drvdata(dev->parent);
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struct host1x_channel_list *chlist = &host->channel_list;
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struct host1x_channel *channel;
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int err;
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channel = acquire_unused_channel(host);
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if (!channel)
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return NULL;
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kref_init(&channel->refcount);
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mutex_init(&channel->submitlock);
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channel->dev = dev;
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err = host1x_hw_channel_init(host, channel, channel->id);
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if (err < 0)
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goto fail;
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err = host1x_cdma_init(&channel->cdma);
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if (err < 0)
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goto fail;
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return channel;
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fail:
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clear_bit(channel->id, chlist->allocated_channels);
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dev_err(dev, "failed to initialize channel\n");
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return NULL;
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}
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EXPORT_SYMBOL(host1x_channel_request);
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