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); 187