drivers/gpu/drm/i915/gem/i915_gem_fence.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright © 2019 Intel Corporation
   5  */
   6
   7 #include "i915_drv.h"
   8 #include "i915_gem_object.h"
   9
  10 struct stub_fence {
  11         struct dma_fence dma;
  12         struct i915_sw_fence chain;
  13 };
  14
  15 static int __i915_sw_fence_call
  16 stub_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
  17 {
  18         struct stub_fence *stub = container_of(fence, typeof(*stub), chain);
  19
  20         switch (state) {
  21         case FENCE_COMPLETE:
  22                 dma_fence_signal(&stub->dma);
  23                 break;
  24
  25         case FENCE_FREE:
  26                 dma_fence_put(&stub->dma);
  27                 break;
  28         }
  29
  30         return NOTIFY_DONE;
  31 }
  32
  33 static const char *stub_driver_name(struct dma_fence *fence)
  34 {
  35         return DRIVER_NAME;
  36 }
  37
  38 static const char *stub_timeline_name(struct dma_fence *fence)
  39 {
  40         return "object";
  41 }
  42
  43 static void stub_release(struct dma_fence *fence)
  44 {
  45         struct stub_fence *stub = container_of(fence, typeof(*stub), dma);
  46
  47         i915_sw_fence_fini(&stub->chain);
  48
  49         BUILD_BUG_ON(offsetof(typeof(*stub), dma));
  50         dma_fence_free(&stub->dma);
  51 }
  52
  53 static const struct dma_fence_ops stub_fence_ops = {
  54         .get_driver_name = stub_driver_name,
  55         .get_timeline_name = stub_timeline_name,
  56         .release = stub_release,
  57 };
  58
  59 struct dma_fence *
  60 i915_gem_object_lock_fence(struct drm_i915_gem_object *obj)
  61 {
  62         struct stub_fence *stub;
  63
  64         assert_object_held(obj);
  65
  66         stub = kmalloc(sizeof(*stub), GFP_KERNEL);
  67         if (!stub)
  68                 return NULL;
  69
  70         i915_sw_fence_init(&stub->chain, stub_notify);
  71         dma_fence_init(&stub->dma, &stub_fence_ops, &stub->chain.wait.lock,
  72                        0, 0);
  73
  74         if (i915_sw_fence_await_reservation(&stub->chain,
  75                                             obj->base.resv, NULL,
  76                                             true, I915_FENCE_TIMEOUT,
  77                                             I915_FENCE_GFP) < 0)
  78                 goto err;
  79
  80         dma_resv_add_excl_fence(obj->base.resv, &stub->dma);
  81
  82         return &stub->dma;
  83
  84 err:
  85         stub_release(&stub->dma);
  86         return NULL;
  87 }
  88
  89 void i915_gem_object_unlock_fence(struct drm_i915_gem_object *obj,
  90                                   struct dma_fence *fence)
  91 {
  92         struct stub_fence *stub = container_of(fence, typeof(*stub), dma);
  93
  94         i915_sw_fence_commit(&stub->chain);
  95 }