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 static 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 91 void host1x_channel_put(struct host1x_channel *channel) 92 { 93 kref_put(&channel->refcount, release_channel); 94 } 95 EXPORT_SYMBOL(host1x_channel_put); 96 97 static 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 */ 123 struct 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; 147 148 fail: 149 clear_bit(channel->id, chlist->allocated_channels); 150 151 dev_err(dev, "failed to initialize channel\n"); 152 153 return NULL; 154 } 155 EXPORT_SYMBOL(host1x_channel_request); 156