tegrakernel/kernel/kernel-4.9/drivers/gpu/drm/i915/i915_sw_fence.c

363 lines
8.1 KiB
C

/*
* (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;
}