Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 1 | /* |
| 2 | * drivers/dma-buf/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/file.h> |
| 18 | #include <linux/fs.h> |
| 19 | #include <linux/uaccess.h> |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 20 | #include <linux/slab.h> |
Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 21 | #include <linux/sync_file.h> |
| 22 | |
Gustavo Padovan | 1fe82e2 | 2016-05-31 16:59:12 -0300 | [diff] [blame^] | 23 | #include "sync_debug.h" |
Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 24 | |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 25 | #define CREATE_TRACE_POINTS |
| 26 | #include "trace/sync.h" |
| 27 | |
Gustavo Padovan | 6f65aa8 | 2016-05-31 16:59:08 -0300 | [diff] [blame] | 28 | struct sw_sync_create_fence_data { |
| 29 | __u32 value; |
| 30 | char name[32]; |
| 31 | __s32 fence; /* fd of new fence */ |
| 32 | }; |
| 33 | |
| 34 | #define SW_SYNC_IOC_MAGIC 'W' |
| 35 | |
| 36 | #define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0,\ |
| 37 | struct sw_sync_create_fence_data) |
| 38 | #define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32) |
| 39 | |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 40 | static const struct fence_ops timeline_fence_ops; |
| 41 | |
| 42 | static inline struct sync_pt *fence_to_sync_pt(struct fence *fence) |
| 43 | { |
| 44 | if (fence->ops != &timeline_fence_ops) |
| 45 | return NULL; |
| 46 | return container_of(fence, struct sync_pt, base); |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * sync_timeline_create() - creates a sync object |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 51 | * @name: sync_timeline name |
| 52 | * |
| 53 | * Creates a new sync_timeline. Returns the sync_timeline object or NULL in |
| 54 | * case of error. |
| 55 | */ |
Gustavo Padovan | b9bc2b7 | 2016-05-31 16:59:11 -0300 | [diff] [blame] | 56 | struct sync_timeline *sync_timeline_create(const char *name) |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 57 | { |
| 58 | struct sync_timeline *obj; |
| 59 | |
| 60 | obj = kzalloc(sizeof(*obj), GFP_KERNEL); |
| 61 | if (!obj) |
| 62 | return NULL; |
| 63 | |
| 64 | kref_init(&obj->kref); |
| 65 | obj->context = fence_context_alloc(1); |
| 66 | strlcpy(obj->name, name, sizeof(obj->name)); |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 67 | |
| 68 | INIT_LIST_HEAD(&obj->child_list_head); |
| 69 | INIT_LIST_HEAD(&obj->active_list_head); |
| 70 | spin_lock_init(&obj->child_list_lock); |
| 71 | |
| 72 | sync_timeline_debug_add(obj); |
| 73 | |
| 74 | return obj; |
| 75 | } |
| 76 | |
| 77 | static void sync_timeline_free(struct kref *kref) |
| 78 | { |
| 79 | struct sync_timeline *obj = |
| 80 | container_of(kref, struct sync_timeline, kref); |
| 81 | |
| 82 | sync_timeline_debug_remove(obj); |
| 83 | |
| 84 | kfree(obj); |
| 85 | } |
| 86 | |
| 87 | static void sync_timeline_get(struct sync_timeline *obj) |
| 88 | { |
| 89 | kref_get(&obj->kref); |
| 90 | } |
| 91 | |
| 92 | static void sync_timeline_put(struct sync_timeline *obj) |
| 93 | { |
| 94 | kref_put(&obj->kref, sync_timeline_free); |
| 95 | } |
| 96 | |
| 97 | /** |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 98 | * sync_timeline_signal() - signal a status change on a sync_timeline |
| 99 | * @obj: sync_timeline to signal |
| 100 | * @inc: num to increment on timeline->value |
| 101 | * |
| 102 | * A sync implementation should call this any time one of it's fences |
| 103 | * has signaled or has an error condition. |
| 104 | */ |
| 105 | static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc) |
| 106 | { |
| 107 | unsigned long flags; |
| 108 | struct sync_pt *pt, *next; |
| 109 | |
| 110 | trace_sync_timeline(obj); |
| 111 | |
| 112 | spin_lock_irqsave(&obj->child_list_lock, flags); |
| 113 | |
| 114 | obj->value += inc; |
| 115 | |
| 116 | list_for_each_entry_safe(pt, next, &obj->active_list_head, |
| 117 | active_list) { |
| 118 | if (fence_is_signaled_locked(&pt->base)) |
| 119 | list_del_init(&pt->active_list); |
| 120 | } |
| 121 | |
| 122 | spin_unlock_irqrestore(&obj->child_list_lock, flags); |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * sync_pt_create() - creates a sync pt |
| 127 | * @parent: fence's parent sync_timeline |
| 128 | * @size: size to allocate for this pt |
| 129 | * @inc: value of the fence |
| 130 | * |
| 131 | * Creates a new sync_pt as a child of @parent. @size bytes will be |
| 132 | * allocated allowing for implementation specific data to be kept after |
| 133 | * the generic sync_timeline struct. Returns the sync_pt object or |
| 134 | * NULL in case of error. |
| 135 | */ |
| 136 | static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size, |
| 137 | unsigned int value) |
| 138 | { |
| 139 | unsigned long flags; |
| 140 | struct sync_pt *pt; |
| 141 | |
| 142 | if (size < sizeof(*pt)) |
| 143 | return NULL; |
| 144 | |
| 145 | pt = kzalloc(size, GFP_KERNEL); |
| 146 | if (!pt) |
| 147 | return NULL; |
| 148 | |
| 149 | spin_lock_irqsave(&obj->child_list_lock, flags); |
| 150 | sync_timeline_get(obj); |
| 151 | fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock, |
| 152 | obj->context, value); |
| 153 | list_add_tail(&pt->child_list, &obj->child_list_head); |
| 154 | INIT_LIST_HEAD(&pt->active_list); |
| 155 | spin_unlock_irqrestore(&obj->child_list_lock, flags); |
| 156 | return pt; |
| 157 | } |
| 158 | |
| 159 | static const char *timeline_fence_get_driver_name(struct fence *fence) |
| 160 | { |
Gustavo Padovan | b9bc2b7 | 2016-05-31 16:59:11 -0300 | [diff] [blame] | 161 | return "sw_sync"; |
Gustavo Padovan | aff9da1 | 2016-05-31 16:59:07 -0300 | [diff] [blame] | 162 | } |
| 163 | |
| 164 | static const char *timeline_fence_get_timeline_name(struct fence *fence) |
| 165 | { |
| 166 | struct sync_timeline *parent = fence_parent(fence); |
| 167 | |
| 168 | return parent->name; |
| 169 | } |
| 170 | |
| 171 | static void timeline_fence_release(struct fence *fence) |
| 172 | { |
| 173 | struct sync_pt *pt = fence_to_sync_pt(fence); |
| 174 | struct sync_timeline *parent = fence_parent(fence); |
| 175 | unsigned long flags; |
| 176 | |
| 177 | spin_lock_irqsave(fence->lock, flags); |
| 178 | list_del(&pt->child_list); |
| 179 | if (WARN_ON_ONCE(!list_empty(&pt->active_list))) |
| 180 | list_del(&pt->active_list); |
| 181 | spin_unlock_irqrestore(fence->lock, flags); |
| 182 | |
| 183 | sync_timeline_put(parent); |
| 184 | fence_free(fence); |
| 185 | } |
| 186 | |
| 187 | static bool timeline_fence_signaled(struct fence *fence) |
| 188 | { |
| 189 | struct sync_timeline *parent = fence_parent(fence); |
| 190 | |
| 191 | return (fence->seqno > parent->value) ? false : true; |
| 192 | } |
| 193 | |
| 194 | static bool timeline_fence_enable_signaling(struct fence *fence) |
| 195 | { |
| 196 | struct sync_pt *pt = fence_to_sync_pt(fence); |
| 197 | struct sync_timeline *parent = fence_parent(fence); |
| 198 | |
| 199 | if (timeline_fence_signaled(fence)) |
| 200 | return false; |
| 201 | |
| 202 | list_add_tail(&pt->active_list, &parent->active_list_head); |
| 203 | return true; |
| 204 | } |
| 205 | |
| 206 | static void timeline_fence_value_str(struct fence *fence, |
| 207 | char *str, int size) |
| 208 | { |
| 209 | snprintf(str, size, "%d", fence->seqno); |
| 210 | } |
| 211 | |
| 212 | static void timeline_fence_timeline_value_str(struct fence *fence, |
| 213 | char *str, int size) |
| 214 | { |
| 215 | struct sync_timeline *parent = fence_parent(fence); |
| 216 | |
| 217 | snprintf(str, size, "%d", parent->value); |
| 218 | } |
| 219 | |
| 220 | static const struct fence_ops timeline_fence_ops = { |
| 221 | .get_driver_name = timeline_fence_get_driver_name, |
| 222 | .get_timeline_name = timeline_fence_get_timeline_name, |
| 223 | .enable_signaling = timeline_fence_enable_signaling, |
| 224 | .signaled = timeline_fence_signaled, |
| 225 | .wait = fence_default_wait, |
| 226 | .release = timeline_fence_release, |
| 227 | .fence_value_str = timeline_fence_value_str, |
| 228 | .timeline_value_str = timeline_fence_timeline_value_str, |
| 229 | }; |
| 230 | |
Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 231 | /* |
| 232 | * *WARNING* |
| 233 | * |
| 234 | * improper use of this can result in deadlocking kernel drivers from userspace. |
| 235 | */ |
| 236 | |
| 237 | /* opening sw_sync create a new sync obj */ |
| 238 | static int sw_sync_debugfs_open(struct inode *inode, struct file *file) |
| 239 | { |
| 240 | struct sync_timeline *obj; |
| 241 | char task_comm[TASK_COMM_LEN]; |
| 242 | |
| 243 | get_task_comm(task_comm, current); |
| 244 | |
Gustavo Padovan | b9bc2b7 | 2016-05-31 16:59:11 -0300 | [diff] [blame] | 245 | obj = sync_timeline_create(task_comm); |
Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 246 | if (!obj) |
| 247 | return -ENOMEM; |
| 248 | |
| 249 | file->private_data = obj; |
| 250 | |
| 251 | return 0; |
| 252 | } |
| 253 | |
| 254 | static int sw_sync_debugfs_release(struct inode *inode, struct file *file) |
| 255 | { |
| 256 | struct sync_timeline *obj = file->private_data; |
| 257 | |
Gustavo Padovan | 7111023 | 2016-05-31 16:59:10 -0300 | [diff] [blame] | 258 | smp_wmb(); |
| 259 | |
| 260 | sync_timeline_put(obj); |
Gustavo Padovan | 1867a23 | 2016-05-31 16:59:05 -0300 | [diff] [blame] | 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | static long sw_sync_ioctl_create_fence(struct sync_timeline *obj, |
| 265 | unsigned long arg) |
| 266 | { |
| 267 | int fd = get_unused_fd_flags(O_CLOEXEC); |
| 268 | int err; |
| 269 | struct sync_pt *pt; |
| 270 | struct sync_file *sync_file; |
| 271 | struct sw_sync_create_fence_data data; |
| 272 | |
| 273 | if (fd < 0) |
| 274 | return fd; |
| 275 | |
| 276 | if (copy_from_user(&data, (void __user *)arg, sizeof(data))) { |
| 277 | err = -EFAULT; |
| 278 | goto err; |
| 279 | } |
| 280 | |
| 281 | pt = sync_pt_create(obj, sizeof(*pt), data.value); |
| 282 | if (!pt) { |
| 283 | err = -ENOMEM; |
| 284 | goto err; |
| 285 | } |
| 286 | |
| 287 | sync_file = sync_file_create(&pt->base); |
| 288 | if (!sync_file) { |
| 289 | fence_put(&pt->base); |
| 290 | err = -ENOMEM; |
| 291 | goto err; |
| 292 | } |
| 293 | |
| 294 | data.fence = fd; |
| 295 | if (copy_to_user((void __user *)arg, &data, sizeof(data))) { |
| 296 | fput(sync_file->file); |
| 297 | err = -EFAULT; |
| 298 | goto err; |
| 299 | } |
| 300 | |
| 301 | fd_install(fd, sync_file->file); |
| 302 | |
| 303 | return 0; |
| 304 | |
| 305 | err: |
| 306 | put_unused_fd(fd); |
| 307 | return err; |
| 308 | } |
| 309 | |
| 310 | static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg) |
| 311 | { |
| 312 | u32 value; |
| 313 | |
| 314 | if (copy_from_user(&value, (void __user *)arg, sizeof(value))) |
| 315 | return -EFAULT; |
| 316 | |
| 317 | sync_timeline_signal(obj, value); |
| 318 | |
| 319 | return 0; |
| 320 | } |
| 321 | |
| 322 | static long sw_sync_ioctl(struct file *file, unsigned int cmd, |
| 323 | unsigned long arg) |
| 324 | { |
| 325 | struct sync_timeline *obj = file->private_data; |
| 326 | |
| 327 | switch (cmd) { |
| 328 | case SW_SYNC_IOC_CREATE_FENCE: |
| 329 | return sw_sync_ioctl_create_fence(obj, arg); |
| 330 | |
| 331 | case SW_SYNC_IOC_INC: |
| 332 | return sw_sync_ioctl_inc(obj, arg); |
| 333 | |
| 334 | default: |
| 335 | return -ENOTTY; |
| 336 | } |
| 337 | } |
| 338 | |
| 339 | const struct file_operations sw_sync_debugfs_fops = { |
| 340 | .open = sw_sync_debugfs_open, |
| 341 | .release = sw_sync_debugfs_release, |
| 342 | .unlocked_ioctl = sw_sync_ioctl, |
| 343 | .compat_ioctl = sw_sync_ioctl, |
| 344 | }; |