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687db220 MP |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Syncpoint dma_fence implementation | |
4 | * | |
5 | * Copyright (c) 2020, NVIDIA Corporation. | |
6 | */ | |
7 | ||
8 | #include <linux/dma-fence.h> | |
9 | #include <linux/file.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/sync_file.h> | |
13 | ||
14 | #include "fence.h" | |
15 | #include "intr.h" | |
16 | #include "syncpt.h" | |
17 | ||
a81cf839 | 18 | static DEFINE_SPINLOCK(lock); |
687db220 MP |
19 | |
20 | struct host1x_syncpt_fence { | |
21 | struct dma_fence base; | |
22 | ||
23 | atomic_t signaling; | |
24 | ||
25 | struct host1x_syncpt *sp; | |
26 | u32 threshold; | |
27 | ||
28 | struct host1x_waitlist *waiter; | |
29 | void *waiter_ref; | |
30 | ||
31 | struct delayed_work timeout_work; | |
32 | }; | |
33 | ||
34 | static const char *host1x_syncpt_fence_get_driver_name(struct dma_fence *f) | |
35 | { | |
36 | return "host1x"; | |
37 | } | |
38 | ||
39 | static const char *host1x_syncpt_fence_get_timeline_name(struct dma_fence *f) | |
40 | { | |
41 | return "syncpoint"; | |
42 | } | |
43 | ||
44 | static struct host1x_syncpt_fence *to_host1x_fence(struct dma_fence *f) | |
45 | { | |
46 | return container_of(f, struct host1x_syncpt_fence, base); | |
47 | } | |
48 | ||
49 | static bool host1x_syncpt_fence_enable_signaling(struct dma_fence *f) | |
50 | { | |
51 | struct host1x_syncpt_fence *sf = to_host1x_fence(f); | |
52 | int err; | |
53 | ||
54 | if (host1x_syncpt_is_expired(sf->sp, sf->threshold)) | |
55 | return false; | |
56 | ||
57 | dma_fence_get(f); | |
58 | ||
59 | /* | |
60 | * The dma_fence framework requires the fence driver to keep a | |
61 | * reference to any fences for which 'enable_signaling' has been | |
62 | * called (and that have not been signalled). | |
63 | * | |
64 | * We provide a userspace API to create arbitrary syncpoint fences, | |
65 | * so we cannot normally guarantee that all fences get signalled. | |
66 | * As such, setup a timeout, so that long-lasting fences will get | |
67 | * reaped eventually. | |
68 | */ | |
69 | schedule_delayed_work(&sf->timeout_work, msecs_to_jiffies(30000)); | |
70 | ||
71 | err = host1x_intr_add_action(sf->sp->host, sf->sp, sf->threshold, | |
72 | HOST1X_INTR_ACTION_SIGNAL_FENCE, f, | |
73 | sf->waiter, &sf->waiter_ref); | |
74 | if (err) { | |
75 | cancel_delayed_work_sync(&sf->timeout_work); | |
76 | dma_fence_put(f); | |
77 | return false; | |
78 | } | |
79 | ||
80 | /* intr framework takes ownership of waiter */ | |
81 | sf->waiter = NULL; | |
82 | ||
83 | /* | |
84 | * The fence may get signalled at any time after the above call, | |
85 | * so we need to initialize all state used by signalling | |
86 | * before it. | |
87 | */ | |
88 | ||
89 | return true; | |
90 | } | |
91 | ||
92 | static void host1x_syncpt_fence_release(struct dma_fence *f) | |
93 | { | |
94 | struct host1x_syncpt_fence *sf = to_host1x_fence(f); | |
95 | ||
96 | if (sf->waiter) | |
97 | kfree(sf->waiter); | |
98 | ||
99 | dma_fence_free(f); | |
100 | } | |
101 | ||
102 | const struct dma_fence_ops host1x_syncpt_fence_ops = { | |
103 | .get_driver_name = host1x_syncpt_fence_get_driver_name, | |
104 | .get_timeline_name = host1x_syncpt_fence_get_timeline_name, | |
105 | .enable_signaling = host1x_syncpt_fence_enable_signaling, | |
106 | .release = host1x_syncpt_fence_release, | |
107 | }; | |
108 | ||
109 | void host1x_fence_signal(struct host1x_syncpt_fence *f) | |
110 | { | |
111 | if (atomic_xchg(&f->signaling, 1)) | |
112 | return; | |
113 | ||
114 | /* | |
115 | * Cancel pending timeout work - if it races, it will | |
116 | * not get 'f->signaling' and return. | |
117 | */ | |
118 | cancel_delayed_work_sync(&f->timeout_work); | |
119 | ||
120 | host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref, false); | |
121 | ||
122 | dma_fence_signal(&f->base); | |
123 | dma_fence_put(&f->base); | |
124 | } | |
125 | ||
126 | static void do_fence_timeout(struct work_struct *work) | |
127 | { | |
128 | struct delayed_work *dwork = (struct delayed_work *)work; | |
129 | struct host1x_syncpt_fence *f = | |
130 | container_of(dwork, struct host1x_syncpt_fence, timeout_work); | |
131 | ||
132 | if (atomic_xchg(&f->signaling, 1)) | |
133 | return; | |
134 | ||
135 | /* | |
136 | * Cancel pending timeout work - if it races, it will | |
137 | * not get 'f->signaling' and return. | |
138 | */ | |
139 | host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref, true); | |
140 | ||
141 | dma_fence_set_error(&f->base, -ETIMEDOUT); | |
142 | dma_fence_signal(&f->base); | |
143 | dma_fence_put(&f->base); | |
144 | } | |
145 | ||
146 | struct dma_fence *host1x_fence_create(struct host1x_syncpt *sp, u32 threshold) | |
147 | { | |
148 | struct host1x_syncpt_fence *fence; | |
149 | ||
150 | fence = kzalloc(sizeof(*fence), GFP_KERNEL); | |
151 | if (!fence) | |
152 | return ERR_PTR(-ENOMEM); | |
153 | ||
154 | fence->waiter = kzalloc(sizeof(*fence->waiter), GFP_KERNEL); | |
c3dbfb9c TR |
155 | if (!fence->waiter) { |
156 | kfree(fence); | |
687db220 | 157 | return ERR_PTR(-ENOMEM); |
c3dbfb9c | 158 | } |
687db220 MP |
159 | |
160 | fence->sp = sp; | |
161 | fence->threshold = threshold; | |
162 | ||
163 | dma_fence_init(&fence->base, &host1x_syncpt_fence_ops, &lock, | |
164 | dma_fence_context_alloc(1), 0); | |
165 | ||
166 | INIT_DELAYED_WORK(&fence->timeout_work, do_fence_timeout); | |
167 | ||
168 | return &fence->base; | |
169 | } | |
170 | EXPORT_SYMBOL(host1x_fence_create); |