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 = 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 37 void host1x_channel_list_free(struct host1x_channel_list *chlist) 38 { 39 kfree(chlist->allocated_channels); 40 kfree(chlist->channels); 41 } 42 43 int 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 } 49 EXPORT_SYMBOL(host1x_job_submit); 50 51 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel) 52 { 53 kref_get(&channel->refcount); 54 55 return channel; 56 } 57 EXPORT_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 */ 67 struct 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 78 void host1x_channel_stop(struct host1x_channel *channel) 79 { 80 struct host1x *host = dev_get_drvdata(channel->dev->parent); 81 82 host1x_hw_cdma_stop(host, &channel->cdma); 83 } 84 EXPORT_SYMBOL(host1x_channel_stop); 85 86 static void release_channel(struct kref *kref) 87 { 88 struct host1x_channel *channel = 89 container_of(kref, struct host1x_channel, refcount); 90 struct host1x *host = dev_get_drvdata(channel->dev->parent); 91 struct host1x_channel_list *chlist = &host->channel_list; 92 93 host1x_hw_cdma_stop(host, &channel->cdma); 94 host1x_cdma_deinit(&channel->cdma); 95 96 clear_bit(channel->id, chlist->allocated_channels); 97 } 98 99 void host1x_channel_put(struct host1x_channel *channel) 100 { 101 kref_put(&channel->refcount, release_channel); 102 } 103 EXPORT_SYMBOL(host1x_channel_put); 104 105 static struct host1x_channel *acquire_unused_channel(struct host1x *host) 106 { 107 struct host1x_channel_list *chlist = &host->channel_list; 108 unsigned int max_channels = host->info->nb_channels; 109 unsigned int index; 110 111 index = find_first_zero_bit(chlist->allocated_channels, max_channels); 112 if (index >= max_channels) { 113 dev_err(host->dev, "failed to find free channel\n"); 114 return NULL; 115 } 116 117 chlist->channels[index].id = index; 118 119 set_bit(index, chlist->allocated_channels); 120 121 return &chlist->channels[index]; 122 } 123 124 /** 125 * host1x_channel_request() - Allocate a channel 126 * @client: Host1x client this channel will be used to send commands to 127 * 128 * Allocates a new host1x channel for @client. May return NULL if CDMA 129 * initialization fails. 130 */ 131 struct host1x_channel *host1x_channel_request(struct host1x_client *client) 132 { 133 struct host1x *host = dev_get_drvdata(client->dev->parent); 134 struct host1x_channel_list *chlist = &host->channel_list; 135 struct host1x_channel *channel; 136 int err; 137 138 channel = acquire_unused_channel(host); 139 if (!channel) 140 return NULL; 141 142 kref_init(&channel->refcount); 143 mutex_init(&channel->submitlock); 144 channel->client = client; 145 channel->dev = client->dev; 146 147 err = host1x_hw_channel_init(host, channel, channel->id); 148 if (err < 0) 149 goto fail; 150 151 err = host1x_cdma_init(&channel->cdma); 152 if (err < 0) 153 goto fail; 154 155 return channel; 156 157 fail: 158 clear_bit(channel->id, chlist->allocated_channels); 159 160 dev_err(client->dev, "failed to initialize channel\n"); 161 162 return NULL; 163 } 164 EXPORT_SYMBOL(host1x_channel_request); 165