2 * (C) Copyright 2016 Intel Corporation
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; version 2
10 #include <linux/slab.h>
11 #include <linux/fence.h>
12 #include <linux/reservation.h>
14 #include "i915_sw_fence.h"
16 static DEFINE_SPINLOCK(i915_sw_fence_lock);
18 static int __i915_sw_fence_notify(struct i915_sw_fence *fence,
19 enum i915_sw_fence_notify state)
21 i915_sw_fence_notify_t fn;
23 fn = (i915_sw_fence_notify_t)(fence->flags & I915_SW_FENCE_MASK);
24 return fn(fence, state);
27 static void i915_sw_fence_free(struct kref *kref)
29 struct i915_sw_fence *fence = container_of(kref, typeof(*fence), kref);
31 WARN_ON(atomic_read(&fence->pending) > 0);
33 if (fence->flags & I915_SW_FENCE_MASK)
34 __i915_sw_fence_notify(fence, FENCE_FREE);
39 static void i915_sw_fence_put(struct i915_sw_fence *fence)
41 kref_put(&fence->kref, i915_sw_fence_free);
44 static struct i915_sw_fence *i915_sw_fence_get(struct i915_sw_fence *fence)
46 kref_get(&fence->kref);
50 static void __i915_sw_fence_wake_up_all(struct i915_sw_fence *fence,
51 struct list_head *continuation)
53 wait_queue_head_t *x = &fence->wait;
54 wait_queue_t *pos, *next;
57 atomic_set_release(&fence->pending, -1); /* 0 -> -1 [done] */
60 * To prevent unbounded recursion as we traverse the graph of
61 * i915_sw_fences, we move the task_list from this, the next ready
62 * fence, to the tail of the original fence's task_list
63 * (and so added to the list to be woken).
66 spin_lock_irqsave_nested(&x->lock, flags, 1 + !!continuation);
68 list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
69 if (pos->func == autoremove_wake_function)
70 pos->func(pos, TASK_NORMAL, 0, continuation);
72 list_move_tail(&pos->task_list, continuation);
78 list_for_each_entry_safe(pos, next,
79 &x->task_list, task_list)
80 pos->func(pos, TASK_NORMAL, 0, &extra);
82 if (list_empty(&extra))
85 list_splice_tail_init(&extra, &x->task_list);
88 spin_unlock_irqrestore(&x->lock, flags);
91 static void __i915_sw_fence_complete(struct i915_sw_fence *fence,
92 struct list_head *continuation)
94 if (!atomic_dec_and_test(&fence->pending))
97 if (fence->flags & I915_SW_FENCE_MASK &&
98 __i915_sw_fence_notify(fence, FENCE_COMPLETE) != NOTIFY_DONE)
101 __i915_sw_fence_wake_up_all(fence, continuation);
104 static void i915_sw_fence_complete(struct i915_sw_fence *fence)
106 if (WARN_ON(i915_sw_fence_done(fence)))
109 __i915_sw_fence_complete(fence, NULL);
112 static void i915_sw_fence_await(struct i915_sw_fence *fence)
114 WARN_ON(atomic_inc_return(&fence->pending) <= 1);
117 void i915_sw_fence_init(struct i915_sw_fence *fence, i915_sw_fence_notify_t fn)
119 BUG_ON((unsigned long)fn & ~I915_SW_FENCE_MASK);
121 init_waitqueue_head(&fence->wait);
122 kref_init(&fence->kref);
123 atomic_set(&fence->pending, 1);
124 fence->flags = (unsigned long)fn;
127 void i915_sw_fence_commit(struct i915_sw_fence *fence)
129 i915_sw_fence_complete(fence);
130 i915_sw_fence_put(fence);
133 static int i915_sw_fence_wake(wait_queue_t *wq, unsigned mode, int flags, void *key)
135 list_del(&wq->task_list);
136 __i915_sw_fence_complete(wq->private, key);
137 i915_sw_fence_put(wq->private);
141 static bool __i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
142 const struct i915_sw_fence * const signaler)
146 if (__test_and_set_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
149 if (fence == signaler)
152 list_for_each_entry(wq, &fence->wait.task_list, task_list) {
153 if (wq->func != i915_sw_fence_wake)
156 if (__i915_sw_fence_check_if_after(wq->private, signaler))
163 static void __i915_sw_fence_clear_checked_bit(struct i915_sw_fence *fence)
167 if (!__test_and_clear_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
170 list_for_each_entry(wq, &fence->wait.task_list, task_list) {
171 if (wq->func != i915_sw_fence_wake)
174 __i915_sw_fence_clear_checked_bit(wq->private);
178 static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
179 const struct i915_sw_fence * const signaler)
184 if (!IS_ENABLED(CONFIG_I915_SW_FENCE_CHECK_DAG))
187 spin_lock_irqsave(&i915_sw_fence_lock, flags);
188 err = __i915_sw_fence_check_if_after(fence, signaler);
189 __i915_sw_fence_clear_checked_bit(fence);
190 spin_unlock_irqrestore(&i915_sw_fence_lock, flags);
195 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
196 struct i915_sw_fence *signaler,
202 if (i915_sw_fence_done(signaler))
205 /* The dependency graph must be acyclic. */
206 if (unlikely(i915_sw_fence_check_if_after(fence, signaler)))
209 INIT_LIST_HEAD(&wq->task_list);
211 wq->func = i915_sw_fence_wake;
212 wq->private = i915_sw_fence_get(fence);
214 i915_sw_fence_await(fence);
216 spin_lock_irqsave(&signaler->wait.lock, flags);
217 if (likely(!i915_sw_fence_done(signaler))) {
218 __add_wait_queue_tail(&signaler->wait, wq);
221 i915_sw_fence_wake(wq, 0, 0, NULL);
224 spin_unlock_irqrestore(&signaler->wait.lock, flags);
229 struct dma_fence_cb {
230 struct fence_cb base;
231 struct i915_sw_fence *fence;
233 struct timer_list timer;
236 static void timer_i915_sw_fence_wake(unsigned long data)
238 struct dma_fence_cb *cb = (struct dma_fence_cb *)data;
240 printk(KERN_WARNING "asynchronous wait on fence %s:%s:%x timed out\n",
241 cb->dma->ops->get_driver_name(cb->dma),
242 cb->dma->ops->get_timeline_name(cb->dma),
247 i915_sw_fence_commit(cb->fence);
248 cb->timer.function = NULL;
251 static void dma_i915_sw_fence_wake(struct fence *dma, struct fence_cb *data)
253 struct dma_fence_cb *cb = container_of(data, typeof(*cb), base);
255 del_timer_sync(&cb->timer);
256 if (cb->timer.function)
257 i915_sw_fence_commit(cb->fence);
263 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
265 unsigned long timeout,
268 struct dma_fence_cb *cb;
271 if (fence_is_signaled(dma))
274 cb = kmalloc(sizeof(*cb), gfp);
276 if (!gfpflags_allow_blocking(gfp))
279 return fence_wait(dma, false);
282 cb->fence = i915_sw_fence_get(fence);
283 i915_sw_fence_await(fence);
286 __setup_timer(&cb->timer,
287 timer_i915_sw_fence_wake, (unsigned long)cb,
290 cb->dma = fence_get(dma);
291 mod_timer(&cb->timer, round_jiffies_up(jiffies + timeout));
294 ret = fence_add_callback(dma, &cb->base, dma_i915_sw_fence_wake);
298 dma_i915_sw_fence_wake(dma, &cb->base);
299 if (ret == -ENOENT) /* fence already signaled */
306 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
307 struct reservation_object *resv,
308 const struct fence_ops *exclude,
310 unsigned long timeout,
314 int ret = 0, pending;
317 struct fence **shared;
318 unsigned int count, i;
320 ret = reservation_object_get_fences_rcu(resv,
321 &excl, &count, &shared);
325 for (i = 0; i < count; i++) {
326 if (shared[i]->ops == exclude)
329 pending = i915_sw_fence_await_dma_fence(fence,
341 for (i = 0; i < count; i++)
342 fence_put(shared[i]);
345 excl = reservation_object_get_excl_rcu(resv);
348 if (ret >= 0 && excl && excl->ops != exclude) {
349 pending = i915_sw_fence_await_dma_fence(fence,