linux/drivers/gpu/drm/nouveau/nouveau_fence.c
Ben Skeggs 906c033e27 drm/nouveau/fence: fix a race where fence->channel can disappear
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2012-05-24 16:55:58 +10:00

212 lines
5.2 KiB
C

/*
* Copyright (C) 2007 Ben Skeggs.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include "drmP.h"
#include "drm.h"
#include <linux/ktime.h>
#include <linux/hrtimer.h>
#include "nouveau_drv.h"
#include "nouveau_ramht.h"
#include "nouveau_fence.h"
#include "nouveau_software.h"
#include "nouveau_dma.h"
void
nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
{
struct nouveau_fence *fence, *fnext;
spin_lock(&fctx->lock);
list_for_each_entry_safe(fence, fnext, &fctx->pending, head) {
if (fence->work)
fence->work(fence->priv, false);
fence->channel = NULL;
list_del(&fence->head);
nouveau_fence_unref(&fence);
}
spin_unlock(&fctx->lock);
}
void
nouveau_fence_context_new(struct nouveau_fence_chan *fctx)
{
INIT_LIST_HEAD(&fctx->pending);
spin_lock_init(&fctx->lock);
}
void
nouveau_fence_update(struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
struct nouveau_fence_priv *priv = nv_engine(dev, NVOBJ_ENGINE_FENCE);
struct nouveau_fence_chan *fctx = chan->engctx[NVOBJ_ENGINE_FENCE];
struct nouveau_fence *fence, *fnext;
spin_lock(&fctx->lock);
list_for_each_entry_safe(fence, fnext, &fctx->pending, head) {
if (priv->read(chan) < fence->sequence)
break;
if (fence->work)
fence->work(fence->priv, true);
fence->channel = NULL;
list_del(&fence->head);
nouveau_fence_unref(&fence);
}
spin_unlock(&fctx->lock);
}
int
nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
struct nouveau_fence_priv *priv = nv_engine(dev, NVOBJ_ENGINE_FENCE);
struct nouveau_fence_chan *fctx = chan->engctx[NVOBJ_ENGINE_FENCE];
int ret;
fence->channel = chan;
fence->timeout = jiffies + (3 * DRM_HZ);
fence->sequence = ++fctx->sequence;
ret = priv->emit(fence);
if (!ret) {
kref_get(&fence->kref);
spin_lock(&fctx->lock);
list_add_tail(&fence->head, &fctx->pending);
spin_unlock(&fctx->lock);
}
return ret;
}
bool
nouveau_fence_done(struct nouveau_fence *fence)
{
if (fence->channel)
nouveau_fence_update(fence->channel);
return !fence->channel;
}
int
nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
{
unsigned long sleep_time = NSEC_PER_MSEC / 1000;
ktime_t t;
int ret = 0;
while (!nouveau_fence_done(fence)) {
if (fence->timeout && time_after_eq(jiffies, fence->timeout)) {
ret = -EBUSY;
break;
}
__set_current_state(intr ? TASK_INTERRUPTIBLE :
TASK_UNINTERRUPTIBLE);
if (lazy) {
t = ktime_set(0, sleep_time);
schedule_hrtimeout(&t, HRTIMER_MODE_REL);
sleep_time *= 2;
if (sleep_time > NSEC_PER_MSEC)
sleep_time = NSEC_PER_MSEC;
}
if (intr && signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
}
__set_current_state(TASK_RUNNING);
return ret;
}
int
nouveau_fence_sync(struct nouveau_fence *fence, struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
struct nouveau_fence_priv *priv = nv_engine(dev, NVOBJ_ENGINE_FENCE);
struct nouveau_channel *prev;
int ret = 0;
prev = fence ? nouveau_channel_get_unlocked(fence->channel) : NULL;
if (prev) {
if (unlikely(prev != chan && !nouveau_fence_done(fence))) {
ret = priv->sync(fence, prev, chan);
if (unlikely(ret))
ret = nouveau_fence_wait(fence, true, false);
}
nouveau_channel_put_unlocked(&prev);
}
return ret;
}
static void
nouveau_fence_del(struct kref *kref)
{
struct nouveau_fence *fence = container_of(kref, typeof(*fence), kref);
kfree(fence);
}
void
nouveau_fence_unref(struct nouveau_fence **pfence)
{
if (*pfence)
kref_put(&(*pfence)->kref, nouveau_fence_del);
*pfence = NULL;
}
struct nouveau_fence *
nouveau_fence_ref(struct nouveau_fence *fence)
{
kref_get(&fence->kref);
return fence;
}
int
nouveau_fence_new(struct nouveau_channel *chan, struct nouveau_fence **pfence)
{
struct nouveau_fence *fence;
int ret = 0;
if (unlikely(!chan->engctx[NVOBJ_ENGINE_FENCE]))
return -ENODEV;
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (!fence)
return -ENOMEM;
kref_init(&fence->kref);
if (chan) {
ret = nouveau_fence_emit(fence, chan);
if (ret)
nouveau_fence_unref(&fence);
}
*pfence = fence;
return ret;
}