1 /* 2 * Tegra host1x Channel 3 * 4 * Copyright (c) 2010-2013, NVIDIA Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 22 #include "channel.h" 23 #include "dev.h" 24 #include "job.h" 25 26 /* Constructor for the host1x device list */ 27 int host1x_channel_list_init(struct host1x_channel_list *chlist, 28 unsigned int num_channels) 29 { 30 chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel), 31 GFP_KERNEL); 32 if (!chlist->channels) 33 return -ENOMEM; 34 35 chlist->allocated_channels = 36 kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long), 37 GFP_KERNEL); 38 if (!chlist->allocated_channels) { 39 kfree(chlist->channels); 40 return -ENOMEM; 41 } 42 43 bitmap_zero(chlist->allocated_channels, num_channels); 44 45 return 0; 46 } 47 48 void host1x_channel_list_free(struct host1x_channel_list *chlist) 49 { 50 kfree(chlist->allocated_channels); 51 kfree(chlist->channels); 52 } 53 54 int host1x_job_submit(struct host1x_job *job) 55 { 56 struct host1x *host = dev_get_drvdata(job->channel->dev->parent); 57 58 return host1x_hw_channel_submit(host, job); 59 } 60 EXPORT_SYMBOL(host1x_job_submit); 61 62 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel) 63 { 64 kref_get(&channel->refcount); 65 66 return channel; 67 } 68 EXPORT_SYMBOL(host1x_channel_get); 69 70 /** 71 * host1x_channel_get_index() - Attempt to get channel reference by index 72 * @host: Host1x device object 73 * @index: Index of channel 74 * 75 * If channel number @index is currently allocated, increase its refcount 76 * and return a pointer to it. Otherwise, return NULL. 77 */ 78 struct host1x_channel *host1x_channel_get_index(struct host1x *host, 79 unsigned int index) 80 { 81 struct host1x_channel *ch = &host->channel_list.channels[index]; 82 83 if (!kref_get_unless_zero(&ch->refcount)) 84 return NULL; 85 86 return ch; 87 } 88 89 static void release_channel(struct kref *kref) 90 { 91 struct host1x_channel *channel = 92 container_of(kref, struct host1x_channel, refcount); 93 struct host1x *host = dev_get_drvdata(channel->dev->parent); 94 struct host1x_channel_list *chlist = &host->channel_list; 95 96 host1x_hw_cdma_stop(host, &channel->cdma); 97 host1x_cdma_deinit(&channel->cdma); 98 99 clear_bit(channel->id, chlist->allocated_channels); 100 } 101 102 void host1x_channel_put(struct host1x_channel *channel) 103 { 104 kref_put(&channel->refcount, release_channel); 105 } 106 EXPORT_SYMBOL(host1x_channel_put); 107 108 static struct host1x_channel *acquire_unused_channel(struct host1x *host) 109 { 110 struct host1x_channel_list *chlist = &host->channel_list; 111 unsigned int max_channels = host->info->nb_channels; 112 unsigned int index; 113 114 index = find_first_zero_bit(chlist->allocated_channels, max_channels); 115 if (index >= max_channels) { 116 dev_err(host->dev, "failed to find free channel\n"); 117 return NULL; 118 } 119 120 chlist->channels[index].id = index; 121 122 set_bit(index, chlist->allocated_channels); 123 124 return &chlist->channels[index]; 125 } 126 127 /** 128 * host1x_channel_request() - Allocate a channel 129 * @device: Host1x unit this channel will be used to send commands to 130 * 131 * Allocates a new host1x channel for @device. If there are no free channels, 132 * this will sleep until one becomes available. May return NULL if CDMA 133 * initialization fails. 134 */ 135 struct host1x_channel *host1x_channel_request(struct device *dev) 136 { 137 struct host1x *host = dev_get_drvdata(dev->parent); 138 struct host1x_channel_list *chlist = &host->channel_list; 139 struct host1x_channel *channel; 140 int err; 141 142 channel = acquire_unused_channel(host); 143 if (!channel) 144 return NULL; 145 146 kref_init(&channel->refcount); 147 mutex_init(&channel->submitlock); 148 channel->dev = dev; 149 150 err = host1x_hw_channel_init(host, channel, channel->id); 151 if (err < 0) 152 goto fail; 153 154 err = host1x_cdma_init(&channel->cdma); 155 if (err < 0) 156 goto fail; 157 158 return channel; 159 160 fail: 161 clear_bit(channel->id, chlist->allocated_channels); 162 163 dev_err(dev, "failed to initialize channel\n"); 164 165 return NULL; 166 } 167 EXPORT_SYMBOL(host1x_channel_request); 168