drivers/gpu/drm/i915/i915_sw_fence.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * i915_sw_fence.h - library routines for N:M synchronisation points
   5  *
   6  * Copyright (C) 2016 Intel Corporation
   7  */
   8
   9 #ifndef _I915_SW_FENCE_H_
  10 #define _I915_SW_FENCE_H_
  11
  12 #include <linux/dma-fence.h>
  13 #include <linux/gfp.h>
  14 #include <linux/kref.h>
  15 #include <linux/notifier.h> /* for NOTIFY_DONE */
  16 #include <linux/wait.h>
  17
  18 struct completion;
  19 struct dma_resv;
  20 struct i915_sw_fence;
  21
  22 enum i915_sw_fence_notify {
  23         FENCE_COMPLETE,
  24         FENCE_FREE
  25 };
  26
  27 typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
  28                                       enum i915_sw_fence_notify state);
  29
  30 struct i915_sw_fence {
  31         wait_queue_head_t wait;
  32         i915_sw_fence_notify_t fn;
  33 #ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
  34         unsigned long flags;
  35 #endif
  36         atomic_t pending;
  37         int error;
  38 };
  39
  40 #define I915_SW_FENCE_CHECKED_BIT       0 /* used internally for DAG checking */
  41
  42 void __i915_sw_fence_init(struct i915_sw_fence *fence,
  43                           i915_sw_fence_notify_t fn,
  44                           const char *name,
  45                           struct lock_class_key *key);
  46 #ifdef CONFIG_LOCKDEP
  47 #define i915_sw_fence_init(fence, fn)                           \
  48 do {                                                            \
  49         static struct lock_class_key __key;                     \
  50                                                                 \
  51         BUILD_BUG_ON((fn) == NULL);                             \
  52         __i915_sw_fence_init((fence), (fn), #fence, &__key);    \
  53 } while (0)
  54 #else
  55 #define i915_sw_fence_init(fence, fn)                           \
  56 do {                                                            \
  57         BUILD_BUG_ON((fn) == NULL);                             \
  58         __i915_sw_fence_init((fence), (fn), NULL, NULL);        \
  59 } while (0)
  60 #endif
  61
  62 void i915_sw_fence_reinit(struct i915_sw_fence *fence);
  63
  64 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
  65 void i915_sw_fence_fini(struct i915_sw_fence *fence);
  66 #else
  67 static inline void i915_sw_fence_fini(struct i915_sw_fence *fence) {}
  68 #endif
  69
  70 void i915_sw_fence_commit(struct i915_sw_fence *fence);
  71
  72 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
  73                                  struct i915_sw_fence *after,
  74                                  wait_queue_entry_t *wq);
  75 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
  76                                      struct i915_sw_fence *after,
  77                                      gfp_t gfp);
  78
  79 struct i915_sw_dma_fence_cb {
  80         struct dma_fence_cb base;
  81         struct i915_sw_fence *fence;
  82 };
  83
  84 int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
  85                                     struct dma_fence *dma,
  86                                     struct i915_sw_dma_fence_cb *cb);
  87 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
  88                                   struct dma_fence *dma,
  89                                   unsigned long timeout,
  90                                   gfp_t gfp);
  91
  92 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
  93                                     struct dma_resv *resv,
  94                                     bool write,
  95                                     unsigned long timeout,
  96                                     gfp_t gfp);
  97
  98 bool i915_sw_fence_await(struct i915_sw_fence *fence);
  99 void i915_sw_fence_complete(struct i915_sw_fence *fence);
 100
 101 static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence)
 102 {
 103         return atomic_read(&fence->pending) <= 0;
 104 }
 105
 106 static inline bool i915_sw_fence_done(const struct i915_sw_fence *fence)
 107 {
 108         return atomic_read(&fence->pending) < 0;
 109 }
 110
 111 static inline void i915_sw_fence_wait(struct i915_sw_fence *fence)
 112 {
 113         wait_event(fence->wait, i915_sw_fence_done(fence));
 114 }
 115
 116 static inline void
 117 i915_sw_fence_set_error_once(struct i915_sw_fence *fence, int error)
 118 {
 119         if (unlikely(error))
 120                 cmpxchg(&fence->error, 0, error);
 121 }
 122
 123 #endif /* _I915_SW_FENCE_H_ */