kernel/drivers/gpu/host1x/channel.c

   1 /*
   2  * Tegra host1x Channel
   3  *
   4  * Copyright (c) 2010-2013, NVIDIA Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21
  22 #include "channel.h"
  23 #include "dev.h"
  24 #include "job.h"
  25
  26 /* Constructor for the host1x device list */
  27 int host1x_channel_list_init(struct host1x *host)
  28 {
  29         INIT_LIST_HEAD(&host->chlist.list);
  30         mutex_init(&host->chlist_mutex);
  31
  32         if (host->info->nb_channels > BITS_PER_LONG) {
  33                 WARN(1, "host1x hardware has more channels than supported by the driver\n");
  34                 return -ENOSYS;
  35         }
  36
  37         return 0;
  38 }
  39
  40 int host1x_job_submit(struct host1x_job *job)
  41 {
  42         struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
  43
  44         return host1x_hw_channel_submit(host, job);
  45 }
  46 EXPORT_SYMBOL(host1x_job_submit);
  47
  48 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
  49 {
  50         int err = 0;
  51
  52         mutex_lock(&channel->reflock);
  53
  54         if (channel->refcount == 0)
  55                 err = host1x_cdma_init(&channel->cdma);
  56
  57         if (!err)
  58                 channel->refcount++;
  59
  60         mutex_unlock(&channel->reflock);
  61
  62         return err ? NULL : channel;
  63 }
  64 EXPORT_SYMBOL(host1x_channel_get);
  65
  66 void host1x_channel_put(struct host1x_channel *channel)
  67 {
  68         mutex_lock(&channel->reflock);
  69
  70         if (channel->refcount == 1) {
  71                 struct host1x *host = dev_get_drvdata(channel->dev->parent);
  72
  73                 host1x_hw_cdma_stop(host, &channel->cdma);
  74                 host1x_cdma_deinit(&channel->cdma);
  75         }
  76
  77         channel->refcount--;
  78
  79         mutex_unlock(&channel->reflock);
  80 }
  81 EXPORT_SYMBOL(host1x_channel_put);
  82
  83 struct host1x_channel *host1x_channel_request(struct device *dev)
  84 {
  85         struct host1x *host = dev_get_drvdata(dev->parent);
  86         int max_channels = host->info->nb_channels;
  87         struct host1x_channel *channel = NULL;
  88         int index, err;
  89
  90         mutex_lock(&host->chlist_mutex);
  91
  92         index = find_first_zero_bit(&host->allocated_channels, max_channels);
  93         if (index >= max_channels)
  94                 goto fail;
  95
  96         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
  97         if (!channel)
  98                 goto fail;
  99
 100         err = host1x_hw_channel_init(host, channel, index);
 101         if (err < 0)
 102                 goto fail;
 103
 104         /* Link device to host1x_channel */
 105         channel->dev = dev;
 106
 107         /* Add to channel list */
 108         list_add_tail(&channel->list, &host->chlist.list);
 109
 110         host->allocated_channels |= BIT(index);
 111
 112         mutex_unlock(&host->chlist_mutex);
 113         return channel;
 114
 115 fail:
 116         dev_err(dev, "failed to init channel\n");
 117         kfree(channel);
 118         mutex_unlock(&host->chlist_mutex);
 119         return NULL;
 120 }
 121 EXPORT_SYMBOL(host1x_channel_request);
 122
 123 void host1x_channel_free(struct host1x_channel *channel)
 124 {
 125         struct host1x *host = dev_get_drvdata(channel->dev->parent);
 126
 127         host->allocated_channels &= ~BIT(channel->id);
 128         list_del(&channel->list);
 129         kfree(channel);
 130 }
 131 EXPORT_SYMBOL(host1x_channel_free);