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path: root/drivers/gpu/drm/i915/i915_sw_fence.c
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Diffstat (limited to 'drivers/gpu/drm/i915/i915_sw_fence.c')
-rw-r--r--drivers/gpu/drm/i915/i915_sw_fence.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
new file mode 100644
index 000000000000..1e5cbc585ca2
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -0,0 +1,362 @@
+/*
+ * (C) Copyright 2016 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/slab.h>
+#include <linux/fence.h>
+#include <linux/reservation.h>
+
+#include "i915_sw_fence.h"
+
+static DEFINE_SPINLOCK(i915_sw_fence_lock);
+
+static int __i915_sw_fence_notify(struct i915_sw_fence *fence,
+ enum i915_sw_fence_notify state)
+{
+ i915_sw_fence_notify_t fn;
+
+ fn = (i915_sw_fence_notify_t)(fence->flags & I915_SW_FENCE_MASK);
+ return fn(fence, state);
+}
+
+static void i915_sw_fence_free(struct kref *kref)
+{
+ struct i915_sw_fence *fence = container_of(kref, typeof(*fence), kref);
+
+ WARN_ON(atomic_read(&fence->pending) > 0);
+
+ if (fence->flags & I915_SW_FENCE_MASK)
+ __i915_sw_fence_notify(fence, FENCE_FREE);
+ else
+ kfree(fence);
+}
+
+static void i915_sw_fence_put(struct i915_sw_fence *fence)
+{
+ kref_put(&fence->kref, i915_sw_fence_free);
+}
+
+static struct i915_sw_fence *i915_sw_fence_get(struct i915_sw_fence *fence)
+{
+ kref_get(&fence->kref);
+ return fence;
+}
+
+static void __i915_sw_fence_wake_up_all(struct i915_sw_fence *fence,
+ struct list_head *continuation)
+{
+ wait_queue_head_t *x = &fence->wait;
+ wait_queue_t *pos, *next;
+ unsigned long flags;
+
+ atomic_set_release(&fence->pending, -1); /* 0 -> -1 [done] */
+
+ /*
+ * To prevent unbounded recursion as we traverse the graph of
+ * i915_sw_fences, we move the task_list from this, the next ready
+ * fence, to the tail of the original fence's task_list
+ * (and so added to the list to be woken).
+ */
+
+ spin_lock_irqsave_nested(&x->lock, flags, 1 + !!continuation);
+ if (continuation) {
+ list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
+ if (pos->func == autoremove_wake_function)
+ pos->func(pos, TASK_NORMAL, 0, continuation);
+ else
+ list_move_tail(&pos->task_list, continuation);
+ }
+ } else {
+ LIST_HEAD(extra);
+
+ do {
+ list_for_each_entry_safe(pos, next,
+ &x->task_list, task_list)
+ pos->func(pos, TASK_NORMAL, 0, &extra);
+
+ if (list_empty(&extra))
+ break;
+
+ list_splice_tail_init(&extra, &x->task_list);
+ } while (1);
+ }
+ spin_unlock_irqrestore(&x->lock, flags);
+}
+
+static void __i915_sw_fence_complete(struct i915_sw_fence *fence,
+ struct list_head *continuation)
+{
+ if (!atomic_dec_and_test(&fence->pending))
+ return;
+
+ if (fence->flags & I915_SW_FENCE_MASK &&
+ __i915_sw_fence_notify(fence, FENCE_COMPLETE) != NOTIFY_DONE)
+ return;
+
+ __i915_sw_fence_wake_up_all(fence, continuation);
+}
+
+static void i915_sw_fence_complete(struct i915_sw_fence *fence)
+{
+ if (WARN_ON(i915_sw_fence_done(fence)))
+ return;
+
+ __i915_sw_fence_complete(fence, NULL);
+}
+
+static void i915_sw_fence_await(struct i915_sw_fence *fence)
+{
+ WARN_ON(atomic_inc_return(&fence->pending) <= 1);
+}
+
+void i915_sw_fence_init(struct i915_sw_fence *fence, i915_sw_fence_notify_t fn)
+{
+ BUG_ON((unsigned long)fn & ~I915_SW_FENCE_MASK);
+
+ init_waitqueue_head(&fence->wait);
+ kref_init(&fence->kref);
+ atomic_set(&fence->pending, 1);
+ fence->flags = (unsigned long)fn;
+}
+
+void i915_sw_fence_commit(struct i915_sw_fence *fence)
+{
+ i915_sw_fence_complete(fence);
+ i915_sw_fence_put(fence);
+}
+
+static int i915_sw_fence_wake(wait_queue_t *wq, unsigned mode, int flags, void *key)
+{
+ list_del(&wq->task_list);
+ __i915_sw_fence_complete(wq->private, key);
+ i915_sw_fence_put(wq->private);
+ return 0;
+}
+
+static bool __i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
+ const struct i915_sw_fence * const signaler)
+{
+ wait_queue_t *wq;
+
+ if (__test_and_set_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
+ return false;
+
+ if (fence == signaler)
+ return true;
+
+ list_for_each_entry(wq, &fence->wait.task_list, task_list) {
+ if (wq->func != i915_sw_fence_wake)
+ continue;
+
+ if (__i915_sw_fence_check_if_after(wq->private, signaler))
+ return true;
+ }
+
+ return false;
+}
+
+static void __i915_sw_fence_clear_checked_bit(struct i915_sw_fence *fence)
+{
+ wait_queue_t *wq;
+
+ if (!__test_and_clear_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
+ return;
+
+ list_for_each_entry(wq, &fence->wait.task_list, task_list) {
+ if (wq->func != i915_sw_fence_wake)
+ continue;
+
+ __i915_sw_fence_clear_checked_bit(wq->private);
+ }
+}
+
+static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
+ const struct i915_sw_fence * const signaler)
+{
+ unsigned long flags;
+ bool err;
+
+ if (!IS_ENABLED(CONFIG_I915_SW_FENCE_CHECK_DAG))
+ return false;
+
+ spin_lock_irqsave(&i915_sw_fence_lock, flags);
+ err = __i915_sw_fence_check_if_after(fence, signaler);
+ __i915_sw_fence_clear_checked_bit(fence);
+ spin_unlock_irqrestore(&i915_sw_fence_lock, flags);
+
+ return err;
+}
+
+int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
+ struct i915_sw_fence *signaler,
+ wait_queue_t *wq)
+{
+ unsigned long flags;
+ int pending;
+
+ if (i915_sw_fence_done(signaler))
+ return 0;
+
+ /* The dependency graph must be acyclic. */
+ if (unlikely(i915_sw_fence_check_if_after(fence, signaler)))
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&wq->task_list);
+ wq->flags = 0;
+ wq->func = i915_sw_fence_wake;
+ wq->private = i915_sw_fence_get(fence);
+
+ i915_sw_fence_await(fence);
+
+ spin_lock_irqsave(&signaler->wait.lock, flags);
+ if (likely(!i915_sw_fence_done(signaler))) {
+ __add_wait_queue_tail(&signaler->wait, wq);
+ pending = 1;
+ } else {
+ i915_sw_fence_wake(wq, 0, 0, NULL);
+ pending = 0;
+ }
+ spin_unlock_irqrestore(&signaler->wait.lock, flags);
+
+ return pending;
+}
+
+struct dma_fence_cb {
+ struct fence_cb base;
+ struct i915_sw_fence *fence;
+ struct fence *dma;
+ struct timer_list timer;
+};
+
+static void timer_i915_sw_fence_wake(unsigned long data)
+{
+ struct dma_fence_cb *cb = (struct dma_fence_cb *)data;
+
+ printk(KERN_WARNING "asynchronous wait on fence %s:%s:%x timed out\n",
+ cb->dma->ops->get_driver_name(cb->dma),
+ cb->dma->ops->get_timeline_name(cb->dma),
+ cb->dma->seqno);
+ fence_put(cb->dma);
+ cb->dma = NULL;
+
+ i915_sw_fence_commit(cb->fence);
+ cb->timer.function = NULL;
+}
+
+static void dma_i915_sw_fence_wake(struct fence *dma, struct fence_cb *data)
+{
+ struct dma_fence_cb *cb = container_of(data, typeof(*cb), base);
+
+ del_timer_sync(&cb->timer);
+ if (cb->timer.function)
+ i915_sw_fence_commit(cb->fence);
+ fence_put(cb->dma);
+
+ kfree(cb);
+}
+
+int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
+ struct fence *dma,
+ unsigned long timeout,
+ gfp_t gfp)
+{
+ struct dma_fence_cb *cb;
+ int ret;
+
+ if (fence_is_signaled(dma))
+ return 0;
+
+ cb = kmalloc(sizeof(*cb), gfp);
+ if (!cb) {
+ if (!gfpflags_allow_blocking(gfp))
+ return -ENOMEM;
+
+ return fence_wait(dma, false);
+ }
+
+ cb->fence = i915_sw_fence_get(fence);
+ i915_sw_fence_await(fence);
+
+ cb->dma = NULL;
+ __setup_timer(&cb->timer,
+ timer_i915_sw_fence_wake, (unsigned long)cb,
+ TIMER_IRQSAFE);
+ if (timeout) {
+ cb->dma = fence_get(dma);
+ mod_timer(&cb->timer, round_jiffies_up(jiffies + timeout));
+ }
+
+ ret = fence_add_callback(dma, &cb->base, dma_i915_sw_fence_wake);
+ if (ret == 0) {
+ ret = 1;
+ } else {
+ dma_i915_sw_fence_wake(dma, &cb->base);
+ if (ret == -ENOENT) /* fence already signaled */
+ ret = 0;
+ }
+
+ return ret;
+}
+
+int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
+ struct reservation_object *resv,
+ const struct fence_ops *exclude,
+ bool write,
+ unsigned long timeout,
+ gfp_t gfp)
+{
+ struct fence *excl;
+ int ret = 0, pending;
+
+ if (write) {
+ struct fence **shared;
+ unsigned int count, i;
+
+ ret = reservation_object_get_fences_rcu(resv,
+ &excl, &count, &shared);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ if (shared[i]->ops == exclude)
+ continue;
+
+ pending = i915_sw_fence_await_dma_fence(fence,
+ shared[i],
+ timeout,
+ gfp);
+ if (pending < 0) {
+ ret = pending;
+ break;
+ }
+
+ ret |= pending;
+ }
+
+ for (i = 0; i < count; i++)
+ fence_put(shared[i]);
+ kfree(shared);
+ } else {
+ excl = reservation_object_get_excl_rcu(resv);
+ }
+
+ if (ret >= 0 && excl && excl->ops != exclude) {
+ pending = i915_sw_fence_await_dma_fence(fence,
+ excl,
+ timeout,
+ gfp);
+ if (pending < 0)
+ ret = pending;
+ else
+ ret |= pending;
+ }
+
+ fence_put(excl);
+
+ return ret;
+}