linux/drivers/gpu/drm/nouveau/nouveau_fence.c
Francisco Jerez 937c3471cc drm/nouveau: Avoid potential race between nouveau_fence_update() and context takedown.
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2010-12-08 03:01:02 +01:00

554 lines
12 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 "nouveau_drv.h"
#include "nouveau_ramht.h"
#include "nouveau_dma.h"
#define USE_REFCNT(dev) (nouveau_private(dev)->chipset >= 0x10)
#define USE_SEMA(dev) (nouveau_private(dev)->chipset >= 0x17)
struct nouveau_fence {
struct nouveau_channel *channel;
struct kref refcount;
struct list_head entry;
uint32_t sequence;
bool signalled;
void (*work)(void *priv, bool signalled);
void *priv;
};
struct nouveau_semaphore {
struct kref ref;
struct drm_device *dev;
struct drm_mm_node *mem;
};
static inline struct nouveau_fence *
nouveau_fence(void *sync_obj)
{
return (struct nouveau_fence *)sync_obj;
}
static void
nouveau_fence_del(struct kref *ref)
{
struct nouveau_fence *fence =
container_of(ref, struct nouveau_fence, refcount);
nouveau_channel_ref(NULL, &fence->channel);
kfree(fence);
}
void
nouveau_fence_update(struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
struct nouveau_fence *tmp, *fence;
uint32_t sequence;
spin_lock(&chan->fence.lock);
/* Fetch the last sequence if the channel is still up and running */
if (likely(!list_empty(&chan->fence.pending))) {
if (USE_REFCNT(dev))
sequence = nvchan_rd32(chan, 0x48);
else
sequence = atomic_read(&chan->fence.last_sequence_irq);
if (chan->fence.sequence_ack == sequence)
goto out;
chan->fence.sequence_ack = sequence;
}
list_for_each_entry_safe(fence, tmp, &chan->fence.pending, entry) {
sequence = fence->sequence;
fence->signalled = true;
list_del(&fence->entry);
if (unlikely(fence->work))
fence->work(fence->priv, true);
kref_put(&fence->refcount, nouveau_fence_del);
if (sequence == chan->fence.sequence_ack)
break;
}
out:
spin_unlock(&chan->fence.lock);
}
int
nouveau_fence_new(struct nouveau_channel *chan, struct nouveau_fence **pfence,
bool emit)
{
struct nouveau_fence *fence;
int ret = 0;
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (!fence)
return -ENOMEM;
kref_init(&fence->refcount);
nouveau_channel_ref(chan, &fence->channel);
if (emit)
ret = nouveau_fence_emit(fence);
if (ret)
nouveau_fence_unref(&fence);
*pfence = fence;
return ret;
}
struct nouveau_channel *
nouveau_fence_channel(struct nouveau_fence *fence)
{
return fence ? nouveau_channel_get_unlocked(fence->channel) : NULL;
}
int
nouveau_fence_emit(struct nouveau_fence *fence)
{
struct nouveau_channel *chan = fence->channel;
struct drm_device *dev = chan->dev;
int ret;
ret = RING_SPACE(chan, 2);
if (ret)
return ret;
if (unlikely(chan->fence.sequence == chan->fence.sequence_ack - 1)) {
nouveau_fence_update(chan);
BUG_ON(chan->fence.sequence ==
chan->fence.sequence_ack - 1);
}
fence->sequence = ++chan->fence.sequence;
kref_get(&fence->refcount);
spin_lock(&chan->fence.lock);
list_add_tail(&fence->entry, &chan->fence.pending);
spin_unlock(&chan->fence.lock);
BEGIN_RING(chan, NvSubSw, USE_REFCNT(dev) ? 0x0050 : 0x0150, 1);
OUT_RING(chan, fence->sequence);
FIRE_RING(chan);
return 0;
}
void
nouveau_fence_work(struct nouveau_fence *fence,
void (*work)(void *priv, bool signalled),
void *priv)
{
BUG_ON(fence->work);
spin_lock(&fence->channel->fence.lock);
if (fence->signalled) {
work(priv, true);
} else {
fence->work = work;
fence->priv = priv;
}
spin_unlock(&fence->channel->fence.lock);
}
void
__nouveau_fence_unref(void **sync_obj)
{
struct nouveau_fence *fence = nouveau_fence(*sync_obj);
if (fence)
kref_put(&fence->refcount, nouveau_fence_del);
*sync_obj = NULL;
}
void *
__nouveau_fence_ref(void *sync_obj)
{
struct nouveau_fence *fence = nouveau_fence(sync_obj);
kref_get(&fence->refcount);
return sync_obj;
}
bool
__nouveau_fence_signalled(void *sync_obj, void *sync_arg)
{
struct nouveau_fence *fence = nouveau_fence(sync_obj);
struct nouveau_channel *chan = fence->channel;
if (fence->signalled)
return true;
nouveau_fence_update(chan);
return fence->signalled;
}
int
__nouveau_fence_wait(void *sync_obj, void *sync_arg, bool lazy, bool intr)
{
unsigned long timeout = jiffies + (3 * DRM_HZ);
unsigned long sleep_time = jiffies + 1;
int ret = 0;
while (1) {
if (__nouveau_fence_signalled(sync_obj, sync_arg))
break;
if (time_after_eq(jiffies, timeout)) {
ret = -EBUSY;
break;
}
__set_current_state(intr ? TASK_INTERRUPTIBLE
: TASK_UNINTERRUPTIBLE);
if (lazy && time_after_eq(jiffies, sleep_time))
schedule_timeout(1);
if (intr && signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
}
__set_current_state(TASK_RUNNING);
return ret;
}
static struct nouveau_semaphore *
alloc_semaphore(struct drm_device *dev)
{
struct drm_nouveau_private *dev_priv = dev->dev_private;
struct nouveau_semaphore *sema;
int ret;
if (!USE_SEMA(dev))
return NULL;
sema = kmalloc(sizeof(*sema), GFP_KERNEL);
if (!sema)
goto fail;
ret = drm_mm_pre_get(&dev_priv->fence.heap);
if (ret)
goto fail;
spin_lock(&dev_priv->fence.lock);
sema->mem = drm_mm_search_free(&dev_priv->fence.heap, 4, 0, 0);
if (sema->mem)
sema->mem = drm_mm_get_block_atomic(sema->mem, 4, 0);
spin_unlock(&dev_priv->fence.lock);
if (!sema->mem)
goto fail;
kref_init(&sema->ref);
sema->dev = dev;
nouveau_bo_wr32(dev_priv->fence.bo, sema->mem->start / 4, 0);
return sema;
fail:
kfree(sema);
return NULL;
}
static void
free_semaphore(struct kref *ref)
{
struct nouveau_semaphore *sema =
container_of(ref, struct nouveau_semaphore, ref);
struct drm_nouveau_private *dev_priv = sema->dev->dev_private;
spin_lock(&dev_priv->fence.lock);
drm_mm_put_block(sema->mem);
spin_unlock(&dev_priv->fence.lock);
kfree(sema);
}
static void
semaphore_work(void *priv, bool signalled)
{
struct nouveau_semaphore *sema = priv;
struct drm_nouveau_private *dev_priv = sema->dev->dev_private;
if (unlikely(!signalled))
nouveau_bo_wr32(dev_priv->fence.bo, sema->mem->start / 4, 1);
kref_put(&sema->ref, free_semaphore);
}
static int
emit_semaphore(struct nouveau_channel *chan, int method,
struct nouveau_semaphore *sema)
{
struct drm_nouveau_private *dev_priv = sema->dev->dev_private;
struct nouveau_fence *fence;
bool smart = (dev_priv->card_type >= NV_50);
int ret;
ret = RING_SPACE(chan, smart ? 8 : 4);
if (ret)
return ret;
if (smart) {
BEGIN_RING(chan, NvSubSw, NV_SW_DMA_SEMAPHORE, 1);
OUT_RING(chan, NvSema);
}
BEGIN_RING(chan, NvSubSw, NV_SW_SEMAPHORE_OFFSET, 1);
OUT_RING(chan, sema->mem->start);
if (smart && method == NV_SW_SEMAPHORE_ACQUIRE) {
/*
* NV50 tries to be too smart and context-switch
* between semaphores instead of doing a "first come,
* first served" strategy like previous cards
* do.
*
* That's bad because the ACQUIRE latency can get as
* large as the PFIFO context time slice in the
* typical DRI2 case where you have several
* outstanding semaphores at the same moment.
*
* If we're going to ACQUIRE, force the card to
* context switch before, just in case the matching
* RELEASE is already scheduled to be executed in
* another channel.
*/
BEGIN_RING(chan, NvSubSw, NV_SW_YIELD, 1);
OUT_RING(chan, 0);
}
BEGIN_RING(chan, NvSubSw, method, 1);
OUT_RING(chan, 1);
if (smart && method == NV_SW_SEMAPHORE_RELEASE) {
/*
* Force the card to context switch, there may be
* another channel waiting for the semaphore we just
* released.
*/
BEGIN_RING(chan, NvSubSw, NV_SW_YIELD, 1);
OUT_RING(chan, 0);
}
/* Delay semaphore destruction until its work is done */
ret = nouveau_fence_new(chan, &fence, true);
if (ret)
return ret;
kref_get(&sema->ref);
nouveau_fence_work(fence, semaphore_work, sema);
nouveau_fence_unref(&fence);
return 0;
}
int
nouveau_fence_sync(struct nouveau_fence *fence,
struct nouveau_channel *wchan)
{
struct nouveau_channel *chan = nouveau_fence_channel(fence);
struct drm_device *dev = wchan->dev;
struct nouveau_semaphore *sema;
int ret = 0;
if (likely(!chan || chan == wchan ||
nouveau_fence_signalled(fence)))
goto out;
sema = alloc_semaphore(dev);
if (!sema) {
/* Early card or broken userspace, fall back to
* software sync. */
ret = nouveau_fence_wait(fence, true, false);
goto out;
}
/* try to take chan's mutex, if we can't take it right away
* we have to fallback to software sync to prevent locking
* order issues
*/
if (!mutex_trylock(&chan->mutex)) {
ret = nouveau_fence_wait(fence, true, false);
goto out_unref;
}
/* Make wchan wait until it gets signalled */
ret = emit_semaphore(wchan, NV_SW_SEMAPHORE_ACQUIRE, sema);
if (ret)
goto out_unlock;
/* Signal the semaphore from chan */
ret = emit_semaphore(chan, NV_SW_SEMAPHORE_RELEASE, sema);
out_unlock:
mutex_unlock(&chan->mutex);
out_unref:
kref_put(&sema->ref, free_semaphore);
out:
if (chan)
nouveau_channel_put_unlocked(&chan);
return ret;
}
int
__nouveau_fence_flush(void *sync_obj, void *sync_arg)
{
return 0;
}
int
nouveau_fence_channel_init(struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
struct drm_nouveau_private *dev_priv = dev->dev_private;
struct nouveau_gpuobj *obj = NULL;
int ret;
/* Create an NV_SW object for various sync purposes */
ret = nouveau_gpuobj_gr_new(chan, NvSw, NV_SW);
if (ret)
return ret;
ret = RING_SPACE(chan, 2);
if (ret)
return ret;
BEGIN_RING(chan, NvSubSw, 0, 1);
OUT_RING(chan, NvSw);
/* Create a DMA object for the shared cross-channel sync area. */
if (USE_SEMA(dev)) {
struct ttm_mem_reg *mem = &dev_priv->fence.bo->bo.mem;
ret = nouveau_gpuobj_dma_new(chan, NV_CLASS_DMA_IN_MEMORY,
mem->start << PAGE_SHIFT,
mem->size, NV_MEM_ACCESS_RW,
NV_MEM_TARGET_VRAM, &obj);
if (ret)
return ret;
ret = nouveau_ramht_insert(chan, NvSema, obj);
nouveau_gpuobj_ref(NULL, &obj);
if (ret)
return ret;
ret = RING_SPACE(chan, 2);
if (ret)
return ret;
BEGIN_RING(chan, NvSubSw, NV_SW_DMA_SEMAPHORE, 1);
OUT_RING(chan, NvSema);
}
FIRE_RING(chan);
INIT_LIST_HEAD(&chan->fence.pending);
spin_lock_init(&chan->fence.lock);
atomic_set(&chan->fence.last_sequence_irq, 0);
return 0;
}
void
nouveau_fence_channel_fini(struct nouveau_channel *chan)
{
struct nouveau_fence *tmp, *fence;
spin_lock(&chan->fence.lock);
list_for_each_entry_safe(fence, tmp, &chan->fence.pending, entry) {
fence->signalled = true;
list_del(&fence->entry);
if (unlikely(fence->work))
fence->work(fence->priv, false);
kref_put(&fence->refcount, nouveau_fence_del);
}
spin_unlock(&chan->fence.lock);
}
int
nouveau_fence_init(struct drm_device *dev)
{
struct drm_nouveau_private *dev_priv = dev->dev_private;
int ret;
/* Create a shared VRAM heap for cross-channel sync. */
if (USE_SEMA(dev)) {
ret = nouveau_bo_new(dev, NULL, 4096, 0, TTM_PL_FLAG_VRAM,
0, 0, false, true, &dev_priv->fence.bo);
if (ret)
return ret;
ret = nouveau_bo_pin(dev_priv->fence.bo, TTM_PL_FLAG_VRAM);
if (ret)
goto fail;
ret = nouveau_bo_map(dev_priv->fence.bo);
if (ret)
goto fail;
ret = drm_mm_init(&dev_priv->fence.heap, 0,
dev_priv->fence.bo->bo.mem.size);
if (ret)
goto fail;
spin_lock_init(&dev_priv->fence.lock);
}
return 0;
fail:
nouveau_bo_unmap(dev_priv->fence.bo);
nouveau_bo_ref(NULL, &dev_priv->fence.bo);
return ret;
}
void
nouveau_fence_fini(struct drm_device *dev)
{
struct drm_nouveau_private *dev_priv = dev->dev_private;
if (USE_SEMA(dev)) {
drm_mm_takedown(&dev_priv->fence.heap);
nouveau_bo_unmap(dev_priv->fence.bo);
nouveau_bo_unpin(dev_priv->fence.bo);
nouveau_bo_ref(NULL, &dev_priv->fence.bo);
}
}