drivers/staging/android/sync.h

   1 /*
   2  * include/linux/sync.h
   3  *
   4  * Copyright (C) 2012 Google, Inc.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  */
  12
  13 #ifndef _LINUX_SYNC_H
  14 #define _LINUX_SYNC_H
  15
  16 #include <linux/types.h>
  17 #include <linux/kref.h>
  18 #include <linux/ktime.h>
  19 #include <linux/list.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/wait.h>
  22 #include <linux/fence.h>
  23
  24 #include "uapi/sync.h"
  25
  26 struct sync_timeline;
  27 struct sync_pt;
  28 struct sync_fence;
  29
  30 /**
  31  * struct sync_timeline_ops - sync object implementation ops
  32  * @driver_name:        name of the implementation
  33  * @dup:                duplicate a sync_pt
  34  * @has_signaled:       returns:
  35  *                        1 if pt has signaled
  36  *                        0 if pt has not signaled
  37  *                       <0 on error
  38  * @compare:            returns:
  39  *                        1 if b will signal before a
  40  *                        0 if a and b will signal at the same time
  41  *                       -1 if a will signal before b
  42  * @free_pt:            called before sync_pt is freed
  43  * @release_obj:        called before sync_timeline is freed
  44  * @fill_driver_data:   write implementation specific driver data to data.
  45  *                        should return an error if there is not enough room
  46  *                        as specified by size.  This information is returned
  47  *                        to userspace by SYNC_IOC_FENCE_INFO.
  48  * @timeline_value_str: fill str with the value of the sync_timeline's counter
  49  * @pt_value_str:       fill str with the value of the sync_pt
  50  */
  51 struct sync_timeline_ops {
  52         const char *driver_name;
  53
  54         /* required */
  55         struct sync_pt * (*dup)(struct sync_pt *pt);
  56
  57         /* required */
  58         int (*has_signaled)(struct sync_pt *pt);
  59
  60         /* required */
  61         int (*compare)(struct sync_pt *a, struct sync_pt *b);
  62
  63         /* optional */
  64         void (*free_pt)(struct sync_pt *sync_pt);
  65
  66         /* optional */
  67         void (*release_obj)(struct sync_timeline *sync_timeline);
  68
  69         /* optional */
  70         int (*fill_driver_data)(struct sync_pt *syncpt, void *data, int size);
  71
  72         /* optional */
  73         void (*timeline_value_str)(struct sync_timeline *timeline, char *str,
  74                                    int size);
  75
  76         /* optional */
  77         void (*pt_value_str)(struct sync_pt *pt, char *str, int size);
  78 };
  79
  80 /**
  81  * struct sync_timeline - sync object
  82  * @kref:               reference count on fence.
  83  * @ops:                ops that define the implementation of the sync_timeline
  84  * @name:               name of the sync_timeline. Useful for debugging
  85  * @destroyed:          set when sync_timeline is destroyed
  86  * @child_list_head:    list of children sync_pts for this sync_timeline
  87  * @child_list_lock:    lock protecting @child_list_head, destroyed, and
  88  *                        sync_pt.status
  89  * @active_list_head:   list of active (unsignaled/errored) sync_pts
  90  * @sync_timeline_list: membership in global sync_timeline_list
  91  */
  92 struct sync_timeline {
  93         struct kref             kref;
  94         const struct sync_timeline_ops  *ops;
  95         char                    name[32];
  96
  97         /* protected by child_list_lock */
  98         bool                    destroyed;
  99         int                     context, value;
 100
 101         struct list_head        child_list_head;
 102         spinlock_t              child_list_lock;
 103
 104         struct list_head        active_list_head;
 105
 106 #ifdef CONFIG_DEBUG_FS
 107         struct list_head        sync_timeline_list;
 108 #endif
 109 };
 110
 111 /**
 112  * struct sync_pt - sync point
 113  * @fence:              base fence class
 114  * @child_list:         membership in sync_timeline.child_list_head
 115  * @active_list:        membership in sync_timeline.active_list_head
 116  * @signaled_list:      membership in temporary signaled_list on stack
 117  * @fence:              sync_fence to which the sync_pt belongs
 118  * @pt_list:            membership in sync_fence.pt_list_head
 119  * @status:             1: signaled, 0:active, <0: error
 120  * @timestamp:          time which sync_pt status transitioned from active to
 121  *                        signaled or error.
 122  */
 123 struct sync_pt {
 124         struct fence base;
 125
 126         struct list_head        child_list;
 127         struct list_head        active_list;
 128 };
 129
 130 static inline struct sync_timeline *sync_pt_parent(struct sync_pt *pt)
 131 {
 132         return container_of(pt->base.lock, struct sync_timeline,
 133                             child_list_lock);
 134 }
 135
 136 struct sync_fence_cb {
 137         struct fence_cb cb;
 138         struct fence *sync_pt;
 139         struct sync_fence *fence;
 140 };
 141
 142 /**
 143  * struct sync_fence - sync fence
 144  * @file:               file representing this fence
 145  * @kref:               reference count on fence.
 146  * @name:               name of sync_fence.  Useful for debugging
 147  * @pt_list_head:       list of sync_pts in the fence.  immutable once fence
 148  *                        is created
 149  * @status:             0: signaled, >0:active, <0: error
 150  *
 151  * @wq:                 wait queue for fence signaling
 152  * @sync_fence_list:    membership in global fence list
 153  */
 154 struct sync_fence {
 155         struct file             *file;
 156         struct kref             kref;
 157         char                    name[32];
 158 #ifdef CONFIG_DEBUG_FS
 159         struct list_head        sync_fence_list;
 160 #endif
 161         int num_fences;
 162
 163         wait_queue_head_t       wq;
 164         atomic_t                status;
 165
 166         struct sync_fence_cb    cbs[];
 167 };
 168
 169 struct sync_fence_waiter;
 170 typedef void (*sync_callback_t)(struct sync_fence *fence,
 171                                 struct sync_fence_waiter *waiter);
 172
 173 /**
 174  * struct sync_fence_waiter - metadata for asynchronous waiter on a fence
 175  * @waiter_list:        membership in sync_fence.waiter_list_head
 176  * @callback:           function pointer to call when fence signals
 177  * @callback_data:      pointer to pass to @callback
 178  */
 179 struct sync_fence_waiter {
 180         wait_queue_t work;
 181         sync_callback_t callback;
 182 };
 183
 184 static inline void sync_fence_waiter_init(struct sync_fence_waiter *waiter,
 185                                           sync_callback_t callback)
 186 {
 187         INIT_LIST_HEAD(&waiter->work.task_list);
 188         waiter->callback = callback;
 189 }
 190
 191 /*
 192  * API for sync_timeline implementers
 193  */
 194
 195 /**
 196  * sync_timeline_create() - creates a sync object
 197  * @ops:        specifies the implementation ops for the object
 198  * @size:       size to allocate for this obj
 199  * @name:       sync_timeline name
 200  *
 201  * Creates a new sync_timeline which will use the implementation specified by
 202  * @ops.  @size bytes will be allocated allowing for implementation specific
 203  * data to be kept after the generic sync_timeline struct.
 204  */
 205 struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
 206                                            int size, const char *name);
 207
 208 /**
 209  * sync_timeline_destroy() - destroys a sync object
 210  * @obj:        sync_timeline to destroy
 211  *
 212  * A sync implementation should call this when the @obj is going away
 213  * (i.e. module unload.)  @obj won't actually be freed until all its children
 214  * sync_pts are freed.
 215  */
 216 void sync_timeline_destroy(struct sync_timeline *obj);
 217
 218 /**
 219  * sync_timeline_signal() - signal a status change on a sync_timeline
 220  * @obj:        sync_timeline to signal
 221  *
 222  * A sync implementation should call this any time one of it's sync_pts
 223  * has signaled or has an error condition.
 224  */
 225 void sync_timeline_signal(struct sync_timeline *obj);
 226
 227 /**
 228  * sync_pt_create() - creates a sync pt
 229  * @parent:     sync_pt's parent sync_timeline
 230  * @size:       size to allocate for this pt
 231  *
 232  * Creates a new sync_pt as a child of @parent.  @size bytes will be
 233  * allocated allowing for implementation specific data to be kept after
 234  * the generic sync_timeline struct.
 235  */
 236 struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size);
 237
 238 /**
 239  * sync_pt_free() - frees a sync pt
 240  * @pt:         sync_pt to free
 241  *
 242  * This should only be called on sync_pts which have been created but
 243  * not added to a fence.
 244  */
 245 void sync_pt_free(struct sync_pt *pt);
 246
 247 /**
 248  * sync_fence_create() - creates a sync fence
 249  * @name:       name of fence to create
 250  * @pt:         sync_pt to add to the fence
 251  *
 252  * Creates a fence containg @pt.  Once this is called, the fence takes
 253  * ownership of @pt.
 254  */
 255 struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt);
 256
 257 /*
 258  * API for sync_fence consumers
 259  */
 260
 261 /**
 262  * sync_fence_merge() - merge two fences
 263  * @name:       name of new fence
 264  * @a:          fence a
 265  * @b:          fence b
 266  *
 267  * Creates a new fence which contains copies of all the sync_pts in both
 268  * @a and @b.  @a and @b remain valid, independent fences.
 269  */
 270 struct sync_fence *sync_fence_merge(const char *name,
 271                                     struct sync_fence *a, struct sync_fence *b);
 272
 273 /**
 274  * sync_fence_fdget() - get a fence from an fd
 275  * @fd:         fd referencing a fence
 276  *
 277  * Ensures @fd references a valid fence, increments the refcount of the backing
 278  * file, and returns the fence.
 279  */
 280 struct sync_fence *sync_fence_fdget(int fd);
 281
 282 /**
 283  * sync_fence_put() - puts a reference of a sync fence
 284  * @fence:      fence to put
 285  *
 286  * Puts a reference on @fence.  If this is the last reference, the fence and
 287  * all it's sync_pts will be freed
 288  */
 289 void sync_fence_put(struct sync_fence *fence);
 290
 291 /**
 292  * sync_fence_install() - installs a fence into a file descriptor
 293  * @fence:      fence to install
 294  * @fd:         file descriptor in which to install the fence
 295  *
 296  * Installs @fence into @fd.  @fd's should be acquired through
 297  * get_unused_fd_flags(O_CLOEXEC).
 298  */
 299 void sync_fence_install(struct sync_fence *fence, int fd);
 300
 301 /**
 302  * sync_fence_wait_async() - registers and async wait on the fence
 303  * @fence:              fence to wait on
 304  * @waiter:             waiter callback struck
 305  *
 306  * Returns 1 if @fence has already signaled.
 307  *
 308  * Registers a callback to be called when @fence signals or has an error.
 309  * @waiter should be initialized with sync_fence_waiter_init().
 310  */
 311 int sync_fence_wait_async(struct sync_fence *fence,
 312                           struct sync_fence_waiter *waiter);
 313
 314 /**
 315  * sync_fence_cancel_async() - cancels an async wait
 316  * @fence:              fence to wait on
 317  * @waiter:             waiter callback struck
 318  *
 319  * returns 0 if waiter was removed from fence's async waiter list.
 320  * returns -ENOENT if waiter was not found on fence's async waiter list.
 321  *
 322  * Cancels a previously registered async wait.  Will fail gracefully if
 323  * @waiter was never registered or if @fence has already signaled @waiter.
 324  */
 325 int sync_fence_cancel_async(struct sync_fence *fence,
 326                             struct sync_fence_waiter *waiter);
 327
 328 /**
 329  * sync_fence_wait() - wait on fence
 330  * @fence:      fence to wait on
 331  * @tiemout:    timeout in ms
 332  *
 333  * Wait for @fence to be signaled or have an error.  Waits indefinitely
 334  * if @timeout < 0
 335  */
 336 int sync_fence_wait(struct sync_fence *fence, long timeout);
 337
 338 #ifdef CONFIG_DEBUG_FS
 339
 340 void sync_timeline_debug_add(struct sync_timeline *obj);
 341 void sync_timeline_debug_remove(struct sync_timeline *obj);
 342 void sync_fence_debug_add(struct sync_fence *fence);
 343 void sync_fence_debug_remove(struct sync_fence *fence);
 344 void sync_dump(void);
 345
 346 #else
 347 # define sync_timeline_debug_add(obj)
 348 # define sync_timeline_debug_remove(obj)
 349 # define sync_fence_debug_add(fence)
 350 # define sync_fence_debug_remove(fence)
 351 # define sync_dump()
 352 #endif
 353 int sync_fence_wake_up_wq(wait_queue_t *curr, unsigned mode,
 354                                  int wake_flags, void *key);
 355
 356 #endif /* _LINUX_SYNC_H */