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