sw_sync.c revision 10f62861b4a2f22cbd6412b3c42c76f0bdfbd648
1/* 2 * drivers/base/sw_sync.c 3 * 4 * Copyright (C) 2012 Google, Inc. 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 */ 16 17#include <linux/kernel.h> 18#include <linux/export.h> 19#include <linux/file.h> 20#include <linux/fs.h> 21#include <linux/miscdevice.h> 22#include <linux/module.h> 23#include <linux/syscalls.h> 24#include <linux/uaccess.h> 25 26#include "sw_sync.h" 27 28static int sw_sync_cmp(u32 a, u32 b) 29{ 30 if (a == b) 31 return 0; 32 33 return ((s32)a - (s32)b) < 0 ? -1 : 1; 34} 35 36struct sync_pt *sw_sync_pt_create(struct sw_sync_timeline *obj, u32 value) 37{ 38 struct sw_sync_pt *pt; 39 40 pt = (struct sw_sync_pt *) 41 sync_pt_create(&obj->obj, sizeof(struct sw_sync_pt)); 42 43 pt->value = value; 44 45 return (struct sync_pt *)pt; 46} 47EXPORT_SYMBOL(sw_sync_pt_create); 48 49static struct sync_pt *sw_sync_pt_dup(struct sync_pt *sync_pt) 50{ 51 struct sw_sync_pt *pt = (struct sw_sync_pt *) sync_pt; 52 struct sw_sync_timeline *obj = 53 (struct sw_sync_timeline *)sync_pt->parent; 54 55 return (struct sync_pt *) sw_sync_pt_create(obj, pt->value); 56} 57 58static int sw_sync_pt_has_signaled(struct sync_pt *sync_pt) 59{ 60 struct sw_sync_pt *pt = (struct sw_sync_pt *)sync_pt; 61 struct sw_sync_timeline *obj = 62 (struct sw_sync_timeline *)sync_pt->parent; 63 64 return sw_sync_cmp(obj->value, pt->value) >= 0; 65} 66 67static int sw_sync_pt_compare(struct sync_pt *a, struct sync_pt *b) 68{ 69 struct sw_sync_pt *pt_a = (struct sw_sync_pt *)a; 70 struct sw_sync_pt *pt_b = (struct sw_sync_pt *)b; 71 72 return sw_sync_cmp(pt_a->value, pt_b->value); 73} 74 75static int sw_sync_fill_driver_data(struct sync_pt *sync_pt, 76 void *data, int size) 77{ 78 struct sw_sync_pt *pt = (struct sw_sync_pt *)sync_pt; 79 80 if (size < sizeof(pt->value)) 81 return -ENOMEM; 82 83 memcpy(data, &pt->value, sizeof(pt->value)); 84 85 return sizeof(pt->value); 86} 87 88static void sw_sync_timeline_value_str(struct sync_timeline *sync_timeline, 89 char *str, int size) 90{ 91 struct sw_sync_timeline *timeline = 92 (struct sw_sync_timeline *)sync_timeline; 93 snprintf(str, size, "%d", timeline->value); 94} 95 96static void sw_sync_pt_value_str(struct sync_pt *sync_pt, 97 char *str, int size) 98{ 99 struct sw_sync_pt *pt = (struct sw_sync_pt *)sync_pt; 100 101 snprintf(str, size, "%d", pt->value); 102} 103 104static struct sync_timeline_ops sw_sync_timeline_ops = { 105 .driver_name = "sw_sync", 106 .dup = sw_sync_pt_dup, 107 .has_signaled = sw_sync_pt_has_signaled, 108 .compare = sw_sync_pt_compare, 109 .fill_driver_data = sw_sync_fill_driver_data, 110 .timeline_value_str = sw_sync_timeline_value_str, 111 .pt_value_str = sw_sync_pt_value_str, 112}; 113 114 115struct sw_sync_timeline *sw_sync_timeline_create(const char *name) 116{ 117 struct sw_sync_timeline *obj = (struct sw_sync_timeline *) 118 sync_timeline_create(&sw_sync_timeline_ops, 119 sizeof(struct sw_sync_timeline), 120 name); 121 122 return obj; 123} 124EXPORT_SYMBOL(sw_sync_timeline_create); 125 126void sw_sync_timeline_inc(struct sw_sync_timeline *obj, u32 inc) 127{ 128 obj->value += inc; 129 130 sync_timeline_signal(&obj->obj); 131} 132EXPORT_SYMBOL(sw_sync_timeline_inc); 133 134#ifdef CONFIG_SW_SYNC_USER 135/* *WARNING* 136 * 137 * improper use of this can result in deadlocking kernel drivers from userspace. 138 */ 139 140/* opening sw_sync create a new sync obj */ 141static int sw_sync_open(struct inode *inode, struct file *file) 142{ 143 struct sw_sync_timeline *obj; 144 char task_comm[TASK_COMM_LEN]; 145 146 get_task_comm(task_comm, current); 147 148 obj = sw_sync_timeline_create(task_comm); 149 if (obj == NULL) 150 return -ENOMEM; 151 152 file->private_data = obj; 153 154 return 0; 155} 156 157static int sw_sync_release(struct inode *inode, struct file *file) 158{ 159 struct sw_sync_timeline *obj = file->private_data; 160 161 sync_timeline_destroy(&obj->obj); 162 return 0; 163} 164 165static long sw_sync_ioctl_create_fence(struct sw_sync_timeline *obj, 166 unsigned long arg) 167{ 168 int fd = get_unused_fd_flags(O_CLOEXEC); 169 int err; 170 struct sync_pt *pt; 171 struct sync_fence *fence; 172 struct sw_sync_create_fence_data data; 173 174 if (fd < 0) 175 return fd; 176 177 if (copy_from_user(&data, (void __user *)arg, sizeof(data))) { 178 err = -EFAULT; 179 goto err; 180 } 181 182 pt = sw_sync_pt_create(obj, data.value); 183 if (pt == NULL) { 184 err = -ENOMEM; 185 goto err; 186 } 187 188 data.name[sizeof(data.name) - 1] = '\0'; 189 fence = sync_fence_create(data.name, pt); 190 if (fence == NULL) { 191 sync_pt_free(pt); 192 err = -ENOMEM; 193 goto err; 194 } 195 196 data.fence = fd; 197 if (copy_to_user((void __user *)arg, &data, sizeof(data))) { 198 sync_fence_put(fence); 199 err = -EFAULT; 200 goto err; 201 } 202 203 sync_fence_install(fence, fd); 204 205 return 0; 206 207err: 208 put_unused_fd(fd); 209 return err; 210} 211 212static long sw_sync_ioctl_inc(struct sw_sync_timeline *obj, unsigned long arg) 213{ 214 u32 value; 215 216 if (copy_from_user(&value, (void __user *)arg, sizeof(value))) 217 return -EFAULT; 218 219 sw_sync_timeline_inc(obj, value); 220 221 return 0; 222} 223 224static long sw_sync_ioctl(struct file *file, unsigned int cmd, 225 unsigned long arg) 226{ 227 struct sw_sync_timeline *obj = file->private_data; 228 229 switch (cmd) { 230 case SW_SYNC_IOC_CREATE_FENCE: 231 return sw_sync_ioctl_create_fence(obj, arg); 232 233 case SW_SYNC_IOC_INC: 234 return sw_sync_ioctl_inc(obj, arg); 235 236 default: 237 return -ENOTTY; 238 } 239} 240 241static const struct file_operations sw_sync_fops = { 242 .owner = THIS_MODULE, 243 .open = sw_sync_open, 244 .release = sw_sync_release, 245 .unlocked_ioctl = sw_sync_ioctl, 246 .compat_ioctl = sw_sync_ioctl, 247}; 248 249static struct miscdevice sw_sync_dev = { 250 .minor = MISC_DYNAMIC_MINOR, 251 .name = "sw_sync", 252 .fops = &sw_sync_fops, 253}; 254 255static int __init sw_sync_device_init(void) 256{ 257 return misc_register(&sw_sync_dev); 258} 259 260static void __exit sw_sync_device_remove(void) 261{ 262 misc_deregister(&sw_sync_dev); 263} 264 265module_init(sw_sync_device_init); 266module_exit(sw_sync_device_remove); 267 268#endif /* CONFIG_SW_SYNC_USER */ 269