drivers/gpu/drm/i915/i915_sw_fence_work.h

   1 /* SPDX-License-Identifier: MIT */
   2
   3 /*
   4  * Copyright © 2019 Intel Corporation
   5  */
   6
   7 #ifndef I915_SW_FENCE_WORK_H
   8 #define I915_SW_FENCE_WORK_H
   9
  10 #include <linux/dma-fence.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/workqueue.h>
  13
  14 #include "i915_sw_fence.h"
  15
  16 struct dma_fence_work;
  17
  18 struct dma_fence_work_ops {
  19         const char *name;
  20         int (*work)(struct dma_fence_work *f);
  21         void (*release)(struct dma_fence_work *f);
  22 };
  23
  24 struct dma_fence_work {
  25         struct dma_fence dma;
  26         spinlock_t lock;
  27
  28         struct i915_sw_fence chain;
  29         struct i915_sw_dma_fence_cb cb;
  30
  31         struct work_struct work;
  32         const struct dma_fence_work_ops *ops;
  33 };
  34
  35 enum {
  36         DMA_FENCE_WORK_IMM = DMA_FENCE_FLAG_USER_BITS,
  37 };
  38
  39 void dma_fence_work_init(struct dma_fence_work *f,
  40                          const struct dma_fence_work_ops *ops);
  41 int dma_fence_work_chain(struct dma_fence_work *f, struct dma_fence *signal);
  42
  43 static inline void dma_fence_work_commit(struct dma_fence_work *f)
  44 {
  45         i915_sw_fence_commit(&f->chain);
  46 }
  47
  48 /**
  49  * dma_fence_work_commit_imm: Commit the fence, and if possible execute locally.
  50  * @f: the fenced worker
  51  *
  52  * Instead of always scheduling a worker to execute the callback (see
  53  * dma_fence_work_commit()), we try to execute the callback immediately in
  54  * the local context. It is required that the fence be committed before it
  55  * is published, and that no other threads try to tamper with the number
  56  * of asynchronous waits on the fence (or else the callback will be
  57  * executed in the wrong context, i.e. not the callers).
  58  */
  59 static inline void dma_fence_work_commit_imm(struct dma_fence_work *f)
  60 {
  61         if (atomic_read(&f->chain.pending) <= 1)
  62                 __set_bit(DMA_FENCE_WORK_IMM, &f->dma.flags);
  63
  64         dma_fence_work_commit(f);
  65 }
  66
  67 #endif /* I915_SW_FENCE_WORK_H */