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