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