drivers/gpu/host1x/channel.c

   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 */
  16 int 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 = bitmap_zalloc(num_channels, GFP_KERNEL);
  25         if (!chlist->allocated_channels) {
  26                 kfree(chlist->channels);
  27                 return -ENOMEM;
  28         }
  29
  30         mutex_init(&chlist->lock);
  31
  32         return 0;
  33 }
  34
  35 void host1x_channel_list_free(struct host1x_channel_list *chlist)
  36 {
  37         bitmap_free(chlist->allocated_channels);
  38         kfree(chlist->channels);
  39 }
  40
  41 int host1x_job_submit(struct host1x_job *job)
  42 {
  43         struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
  44
  45         return host1x_hw_channel_submit(host, job);
  46 }
  47 EXPORT_SYMBOL(host1x_job_submit);
  48
  49 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
  50 {
  51         kref_get(&channel->refcount);
  52
  53         return channel;
  54 }
  55 EXPORT_SYMBOL(host1x_channel_get);
  56
  57 /**
  58  * host1x_channel_get_index() - Attempt to get channel reference by index
  59  * @host: Host1x device object
  60  * @index: Index of channel
  61  *
  62  * If channel number @index is currently allocated, increase its refcount
  63  * and return a pointer to it. Otherwise, return NULL.
  64  */
  65 struct host1x_channel *host1x_channel_get_index(struct host1x *host,
  66                                                 unsigned int index)
  67 {
  68         struct host1x_channel *ch = &host->channel_list.channels[index];
  69
  70         if (!kref_get_unless_zero(&ch->refcount))
  71                 return NULL;
  72
  73         return ch;
  74 }
  75
  76 void host1x_channel_stop(struct host1x_channel *channel)
  77 {
  78         struct host1x *host = dev_get_drvdata(channel->dev->parent);
  79
  80         host1x_hw_cdma_stop(host, &channel->cdma);
  81 }
  82 EXPORT_SYMBOL(host1x_channel_stop);
  83
  84 /**
  85  * host1x_channel_stop_all() - disable CDMA on allocated channels
  86  * @host: host1x instance
  87  *
  88  * Stop CDMA on allocated channels
  89  */
  90 void host1x_channel_stop_all(struct host1x *host)
  91 {
  92         struct host1x_channel_list *chlist = &host->channel_list;
  93         int bit;
  94
  95         mutex_lock(&chlist->lock);
  96
  97         for_each_set_bit(bit, chlist->allocated_channels, host->info->nb_channels)
  98                 host1x_channel_stop(&chlist->channels[bit]);
  99
 100         mutex_unlock(&chlist->lock);
 101 }
 102
 103 static void release_channel(struct kref *kref)
 104 {
 105         struct host1x_channel *channel =
 106                 container_of(kref, struct host1x_channel, refcount);
 107         struct host1x *host = dev_get_drvdata(channel->dev->parent);
 108         struct host1x_channel_list *chlist = &host->channel_list;
 109
 110         host1x_hw_cdma_stop(host, &channel->cdma);
 111         host1x_cdma_deinit(&channel->cdma);
 112
 113         clear_bit(channel->id, chlist->allocated_channels);
 114 }
 115
 116 void host1x_channel_put(struct host1x_channel *channel)
 117 {
 118         kref_put(&channel->refcount, release_channel);
 119 }
 120 EXPORT_SYMBOL(host1x_channel_put);
 121
 122 static struct host1x_channel *acquire_unused_channel(struct host1x *host)
 123 {
 124         struct host1x_channel_list *chlist = &host->channel_list;
 125         unsigned int max_channels = host->info->nb_channels;
 126         unsigned int index;
 127
 128         mutex_lock(&chlist->lock);
 129
 130         index = find_first_zero_bit(chlist->allocated_channels, max_channels);
 131         if (index >= max_channels) {
 132                 mutex_unlock(&chlist->lock);
 133                 dev_err(host->dev, "failed to find free channel\n");
 134                 return NULL;
 135         }
 136
 137         chlist->channels[index].id = index;
 138
 139         set_bit(index, chlist->allocated_channels);
 140
 141         mutex_unlock(&chlist->lock);
 142
 143         return &chlist->channels[index];
 144 }
 145
 146 /**
 147  * host1x_channel_request() - Allocate a channel
 148  * @client: Host1x client this channel will be used to send commands to
 149  *
 150  * Allocates a new host1x channel for @client. May return NULL if CDMA
 151  * initialization fails.
 152  */
 153 struct host1x_channel *host1x_channel_request(struct host1x_client *client)
 154 {
 155         struct host1x *host = dev_get_drvdata(client->dev->parent);
 156         struct host1x_channel_list *chlist = &host->channel_list;
 157         struct host1x_channel *channel;
 158         int err;
 159
 160         channel = acquire_unused_channel(host);
 161         if (!channel)
 162                 return NULL;
 163
 164         kref_init(&channel->refcount);
 165         mutex_init(&channel->submitlock);
 166         channel->client = client;
 167         channel->dev = client->dev;
 168
 169         err = host1x_hw_channel_init(host, channel, channel->id);
 170         if (err < 0)
 171                 goto fail;
 172
 173         err = host1x_cdma_init(&channel->cdma);
 174         if (err < 0)
 175                 goto fail;
 176
 177         return channel;
 178
 179 fail:
 180         clear_bit(channel->id, chlist->allocated_channels);
 181
 182         dev_err(client->dev, "failed to initialize channel\n");
 183
 184         return NULL;
 185 }
 186 EXPORT_SYMBOL(host1x_channel_request);