1 /* $NetBSD: i915_gem_fence.c,v 1.4 2021/12/19 12:36:15 riastradh Exp $ */
2
3 /*
4 * SPDX-License-Identifier: MIT
5 *
6 * Copyright © 2019 Intel Corporation
7 */
8
9 #include <sys/cdefs.h>
10 __KERNEL_RCSID(0, "$NetBSD: i915_gem_fence.c,v 1.4 2021/12/19 12:36:15 riastradh Exp $");
11
12 #include "i915_drv.h"
13 #include "i915_gem_object.h"
14
15 struct stub_fence {
16 struct dma_fence dma;
17 spinlock_t lock;
18 struct i915_sw_fence chain;
19 };
20
21 static int __i915_sw_fence_call
stub_notify(struct i915_sw_fence * fence,enum i915_sw_fence_notify state)22 stub_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
23 {
24 struct stub_fence *stub = container_of(fence, typeof(*stub), chain);
25
26 switch (state) {
27 case FENCE_COMPLETE:
28 dma_fence_signal(&stub->dma);
29 break;
30
31 case FENCE_FREE:
32 dma_fence_put(&stub->dma);
33 break;
34 }
35
36 return NOTIFY_DONE;
37 }
38
stub_driver_name(struct dma_fence * fence)39 static const char *stub_driver_name(struct dma_fence *fence)
40 {
41 return DRIVER_NAME;
42 }
43
stub_timeline_name(struct dma_fence * fence)44 static const char *stub_timeline_name(struct dma_fence *fence)
45 {
46 return "object";
47 }
48
stub_release(struct dma_fence * fence)49 static void stub_release(struct dma_fence *fence)
50 {
51 struct stub_fence *stub = container_of(fence, typeof(*stub), dma);
52
53 i915_sw_fence_fini(&stub->chain);
54
55 BUILD_BUG_ON(offsetof(typeof(*stub), dma));
56 spin_lock_destroy(&stub->lock);
57 dma_fence_free(&stub->dma);
58 }
59
60 static const struct dma_fence_ops stub_fence_ops = {
61 .get_driver_name = stub_driver_name,
62 .get_timeline_name = stub_timeline_name,
63 .release = stub_release,
64 };
65
66 struct dma_fence *
i915_gem_object_lock_fence(struct drm_i915_gem_object * obj)67 i915_gem_object_lock_fence(struct drm_i915_gem_object *obj)
68 {
69 struct stub_fence *stub;
70
71 assert_object_held(obj);
72
73 stub = kmalloc(sizeof(*stub), GFP_KERNEL);
74 if (!stub)
75 return NULL;
76
77 i915_sw_fence_init(&stub->chain, stub_notify);
78 spin_lock_init(&stub->lock);
79 dma_fence_init(&stub->dma, &stub_fence_ops, &stub->lock,
80 0, 0);
81
82 if (i915_sw_fence_await_reservation(&stub->chain,
83 obj->base.resv, NULL,
84 true, I915_FENCE_TIMEOUT,
85 I915_FENCE_GFP) < 0)
86 goto err;
87
88 dma_resv_add_excl_fence(obj->base.resv, &stub->dma);
89
90 return &stub->dma;
91
92 err:
93 stub_release(&stub->dma);
94 return NULL;
95 }
96
i915_gem_object_unlock_fence(struct drm_i915_gem_object * obj,struct dma_fence * fence)97 void i915_gem_object_unlock_fence(struct drm_i915_gem_object *obj,
98 struct dma_fence *fence)
99 {
100 struct stub_fence *stub = container_of(fence, typeof(*stub), dma);
101
102 i915_sw_fence_commit(&stub->chain);
103 }
104