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
  47 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
  48 {
  49         int err = 0;
  50
  51         mutex_lock(&channel->reflock);
  52
  53         if (channel->refcount == 0)
  54                 err = host1x_cdma_init(&channel->cdma);
  55
  56         if (!err)
  57                 channel->refcount++;
  58
  59         mutex_unlock(&channel->reflock);
  60
  61         return err ? NULL : channel;
  62 }
  63
  64 void host1x_channel_put(struct host1x_channel *channel)
  65 {
  66         mutex_lock(&channel->reflock);
  67
  68         if (channel->refcount == 1) {
  69                 struct host1x *host = dev_get_drvdata(channel->dev->parent);
  70
  71                 host1x_hw_cdma_stop(host, &channel->cdma);
  72                 host1x_cdma_deinit(&channel->cdma);
  73         }
  74
  75         channel->refcount--;
  76
  77         mutex_unlock(&channel->reflock);
  78 }
  79
  80 struct host1x_channel *host1x_channel_request(struct device *dev)
  81 {
  82         struct host1x *host = dev_get_drvdata(dev->parent);
  83         int max_channels = host->info->nb_channels;
  84         struct host1x_channel *channel = NULL;
  85         int index, err;
  86
  87         mutex_lock(&host->chlist_mutex);
  88
  89         index = find_first_zero_bit(&host->allocated_channels, max_channels);
  90         if (index >= max_channels)
  91                 goto fail;
  92
  93         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
  94         if (!channel)
  95                 goto fail;
  96
  97         err = host1x_hw_channel_init(host, channel, index);
  98         if (err < 0)
  99                 goto fail;
 100
 101         /* Link device to host1x_channel */
 102         channel->dev = dev;
 103
 104         /* Add to channel list */
 105         list_add_tail(&channel->list, &host->chlist.list);
 106
 107         host->allocated_channels |= BIT(index);
 108
 109         mutex_unlock(&host->chlist_mutex);
 110         return channel;
 111
 112 fail:
 113         dev_err(dev, "failed to init channel\n");
 114         kfree(channel);
 115         mutex_unlock(&host->chlist_mutex);
 116         return NULL;
 117 }
 118
 119 void host1x_channel_free(struct host1x_channel *channel)
 120 {
 121         struct host1x *host = dev_get_drvdata(channel->dev->parent);
 122
 123         host->allocated_channels &= ~BIT(channel->id);
 124         list_del(&channel->list);
 125         kfree(channel);
 126 }