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); 161