[PATCH 3/4] drm/radeon: rework fence handling, drop fence list
j.glisse at gmail.com
j.glisse at gmail.com
Wed May 2 13:20:12 PDT 2012
From: Jerome Glisse <jglisse at redhat.com>
Using 64bits fence sequence we can directly compare sequence
number to know if a fence is signaled or not. Thus the fence
list became useless, so does the fence lock that mainly
protected the fence list.
Things like ring.ready are no longer behind a lock, this should
be ok as ring.ready is initialized once and will only change
when facing lockup. Worst case is that we return an -EBUSY just
after a successfull GPU reset, or we go into wait state instead
of returning -EBUSY (thus delaying reporting -EBUSY to fence
wait caller).
Signed-off-by: Jerome Glisse <jglisse at redhat.com>
---
drivers/gpu/drm/radeon/radeon.h | 6 +-
drivers/gpu/drm/radeon/radeon_device.c | 1 -
drivers/gpu/drm/radeon/radeon_fence.c | 278 ++++++++++++--------------------
3 files changed, 102 insertions(+), 183 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 4c5a667..141aee2 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -286,15 +286,12 @@ struct radeon_fence_driver {
uint64_t last_seq;
unsigned long last_activity;
wait_queue_head_t queue;
- struct list_head emitted;
- struct list_head signaled;
bool initialized;
};
struct radeon_fence {
struct radeon_device *rdev;
struct kref kref;
- struct list_head list;
/* protected by radeon_fence.lock */
uint64_t seq;
bool emitted;
@@ -316,7 +313,7 @@ int radeon_fence_wait_next(struct radeon_device *rdev, int ring);
int radeon_fence_wait_empty(struct radeon_device *rdev, int ring);
struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence);
void radeon_fence_unref(struct radeon_fence **fence);
-int radeon_fence_count_emitted(struct radeon_device *rdev, int ring);
+unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring);
/*
* Tiling registers
@@ -1488,7 +1485,6 @@ struct radeon_device {
struct radeon_mode_info mode_info;
struct radeon_scratch scratch;
struct radeon_mman mman;
- rwlock_t fence_lock;
struct radeon_fence_driver fence_drv[RADEON_NUM_RINGS];
struct radeon_ring ring[RADEON_NUM_RINGS];
bool ib_pool_ready;
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 3880aad..290b8d0 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -746,7 +746,6 @@ int radeon_device_init(struct radeon_device *rdev,
mutex_init(&rdev->gem.mutex);
mutex_init(&rdev->pm.mutex);
mutex_init(&rdev->vram_mutex);
- rwlock_init(&rdev->fence_lock);
INIT_LIST_HEAD(&rdev->gem.objects);
init_waitqueue_head(&rdev->irq.vblank_queue);
init_waitqueue_head(&rdev->irq.idle_queue);
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 6da1535..3f34f7b 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -65,32 +65,22 @@ static u64 radeon_fence_read(struct radeon_device *rdev, int ring)
int radeon_fence_emit(struct radeon_device *rdev, struct radeon_fence *fence)
{
- unsigned long irq_flags;
-
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
if (fence->emitted) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
return 0;
}
fence->seq = atomic64_inc_return(&rdev->fence_drv[fence->ring].seq);
+ /* there is small chance that we overwritte a bigger last_emited
+ * value, but in normal usage this
+ */
radeon_fence_ring_emit(rdev, fence->ring, fence);
trace_radeon_fence_emit(rdev->ddev, fence->seq);
fence->emitted = true;
- /* are we the first fence on a previusly idle ring? */
- if (list_empty(&rdev->fence_drv[fence->ring].emitted)) {
- rdev->fence_drv[fence->ring].last_activity = jiffies;
- }
- list_move_tail(&fence->list, &rdev->fence_drv[fence->ring].emitted);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
return 0;
}
-static bool radeon_fence_poll_locked(struct radeon_device *rdev, int ring)
+static bool radeon_fence_poll(struct radeon_device *rdev, int ring)
{
- struct radeon_fence *fence;
- struct list_head *i, *n;
uint64_t seq;
- bool wake = false;
seq = radeon_fence_read(rdev, ring);
if (seq == rdev->fence_drv[ring].last_seq)
@@ -98,40 +88,15 @@ static bool radeon_fence_poll_locked(struct radeon_device *rdev, int ring)
rdev->fence_drv[ring].last_seq = seq;
rdev->fence_drv[ring].last_activity = jiffies;
-
- n = NULL;
- list_for_each(i, &rdev->fence_drv[ring].emitted) {
- fence = list_entry(i, struct radeon_fence, list);
- if (fence->seq == seq) {
- n = i;
- break;
- }
- }
- /* all fence previous to this one are considered as signaled */
- if (n) {
- i = n;
- do {
- n = i->prev;
- list_move_tail(i, &rdev->fence_drv[ring].signaled);
- fence = list_entry(i, struct radeon_fence, list);
- fence->signaled = true;
- i = n;
- } while (i != &rdev->fence_drv[ring].emitted);
- wake = true;
- }
- return wake;
+ return true;
}
static void radeon_fence_destroy(struct kref *kref)
{
- unsigned long irq_flags;
- struct radeon_fence *fence;
+ struct radeon_fence *fence;
fence = container_of(kref, struct radeon_fence, kref);
- write_lock_irqsave(&fence->rdev->fence_lock, irq_flags);
- list_del(&fence->list);
fence->emitted = false;
- write_unlock_irqrestore(&fence->rdev->fence_lock, irq_flags);
if (fence->semaphore.sa_bo) {
radeon_semaphore_free(fence->rdev, fence);
}
@@ -153,78 +118,95 @@ int radeon_fence_create(struct radeon_device *rdev,
(*fence)->seq = 0;
(*fence)->ring = ring;
(*fence)->semaphore.sa_bo = NULL;
- INIT_LIST_HEAD(&(*fence)->list);
return 0;
}
bool radeon_fence_signaled(struct radeon_fence *fence)
{
- unsigned long irq_flags;
- bool signaled = false;
+ struct radeon_device *rdev;
- if (!fence)
+ if (!fence) {
return true;
+ }
- write_lock_irqsave(&fence->rdev->fence_lock, irq_flags);
- signaled = fence->signaled;
+ rdev = fence->rdev;
+ if (!fence->emitted) {
+ dev_warn(rdev->dev, "Querying an unemitted fence : %p !\n", fence);
+ fence->signaled = true;
+ return true;
+ }
+ if (fence->signaled) {
+ return true;
+ }
+ if (rdev->fence_drv[fence->ring].last_seq >= fence->seq) {
+ fence->signaled = true;
+ return true;
+ }
/* if we are shuting down report all fence as signaled */
- if (fence->rdev->shutdown) {
- signaled = true;
+ if (rdev->shutdown) {
+ fence->signaled = true;
+ return true;
}
- if (!fence->emitted) {
- WARN(1, "Querying an unemitted fence : %p !\n", fence);
- signaled = true;
+ if (!fence->signaled) {
+ radeon_fence_poll(fence->rdev, fence->ring);
+ if (rdev->fence_drv[fence->ring].last_seq >= fence->seq) {
+ fence->signaled = true;
+ return true;
+ }
}
- if (!signaled) {
- radeon_fence_poll_locked(fence->rdev, fence->ring);
- signaled = fence->signaled;
+ return fence->signaled;
+}
+
+bool radeon_seq_signaled(struct radeon_device *rdev, u64 seq, unsigned ring)
+{
+ if (rdev->fence_drv[ring].last_seq >= seq) {
+ return true;
+ }
+ radeon_fence_poll(rdev, ring);
+ if (rdev->fence_drv[ring].last_seq >= seq) {
+ return true;
}
- write_unlock_irqrestore(&fence->rdev->fence_lock, irq_flags);
- return signaled;
+ return false;
}
-int radeon_fence_wait(struct radeon_fence *fence, bool intr)
+static int radeon_wait_seq(struct radeon_device *rdev, u64 target_seq,
+ unsigned ring, bool intr)
{
- struct radeon_device *rdev;
- unsigned long irq_flags, timeout;
- u64 seq;
- int i, r;
+ unsigned long timeout;
+ uint64_t seq;
bool signaled;
+ int r;
- if (fence == NULL) {
- WARN(1, "Querying an invalid fence : %p !\n", fence);
- return -EINVAL;
- }
+ while (target_seq > rdev->fence_drv[ring].last_seq) {
+ if (!rdev->ring[ring].ready) {
+ return -EBUSY;
+ }
- rdev = fence->rdev;
- signaled = radeon_fence_signaled(fence);
- while (!signaled) {
- read_lock_irqsave(&rdev->fence_lock, irq_flags);
timeout = jiffies - RADEON_FENCE_JIFFIES_TIMEOUT;
- if (time_after(rdev->fence_drv[fence->ring].last_activity, timeout)) {
+ if (time_after(rdev->fence_drv[ring].last_activity, timeout)) {
/* the normal case, timeout is somewhere before last_activity */
- timeout = rdev->fence_drv[fence->ring].last_activity - timeout;
+ timeout = rdev->fence_drv[ring].last_activity - timeout;
} else {
/* either jiffies wrapped around, or no fence was signaled in the last 500ms
- * anyway we will just wait for the minimum amount and then check for a lockup */
+ * anyway we will just wait for the minimum amount and then check for a lockup
+ */
timeout = 1;
}
/* save current sequence value used to check for GPU lockups */
- seq = rdev->fence_drv[fence->ring].last_seq;
- read_unlock_irqrestore(&rdev->fence_lock, irq_flags);
+ seq = rdev->fence_drv[ring].last_seq;
trace_radeon_fence_wait_begin(rdev->ddev, seq);
- radeon_irq_kms_sw_irq_get(rdev, fence->ring);
+ radeon_irq_kms_sw_irq_get(rdev, ring);
if (intr) {
- r = wait_event_interruptible_timeout(
- rdev->fence_drv[fence->ring].queue,
- (signaled = radeon_fence_signaled(fence)), timeout);
+ r = wait_event_interruptible_timeout(rdev->fence_drv[ring].queue,
+ (signaled = radeon_seq_signaled(rdev, target_seq, ring)),
+ timeout);
} else {
- r = wait_event_timeout(
- rdev->fence_drv[fence->ring].queue,
- (signaled = radeon_fence_signaled(fence)), timeout);
+ r = wait_event_timeout(rdev->fence_drv[ring].queue,
+ (signaled = radeon_seq_signaled(rdev, target_seq, ring)),
+ timeout);
}
- radeon_irq_kms_sw_irq_put(rdev, fence->ring);
+ radeon_irq_kms_sw_irq_put(rdev, ring);
if (unlikely(r < 0)) {
return r;
}
@@ -237,28 +219,18 @@ int radeon_fence_wait(struct radeon_fence *fence, bool intr)
continue;
}
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
/* check if sequence value has changed since last_activity */
- if (seq != rdev->fence_drv[fence->ring].last_seq) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
+ if (seq != rdev->fence_drv[ring].last_seq) {
continue;
}
- /* change sequence value on all rings, so nobody else things there is a lockup */
- for (i = 0; i < RADEON_NUM_RINGS; ++i)
- rdev->fence_drv[i].last_seq -= 0x10000;
-
- rdev->fence_drv[fence->ring].last_activity = jiffies;
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-
- if (radeon_ring_is_lockup(rdev, fence->ring, &rdev->ring[fence->ring])) {
-
+ if (radeon_ring_is_lockup(rdev, ring, &rdev->ring[ring])) {
/* good news we believe it's a lockup */
dev_warn(rdev->dev, "GPU lockup (waiting for 0x%016llx last fence id 0x%016llx)\n",
- fence->seq, seq);
+ target_seq, seq);
/* mark the ring as not ready any more */
- rdev->ring[fence->ring].ready = false;
+ rdev->ring[ring].ready = false;
return -EDEADLK;
}
}
@@ -266,52 +238,31 @@ int radeon_fence_wait(struct radeon_fence *fence, bool intr)
return 0;
}
-int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
+int radeon_fence_wait(struct radeon_fence *fence, bool intr)
{
- unsigned long irq_flags;
- struct radeon_fence *fence;
int r;
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
- if (!rdev->ring[ring].ready) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return -EBUSY;
+ if (fence == NULL) {
+ WARN(1, "Querying an invalid fence : %p !\n", fence);
+ return -EINVAL;
}
- if (list_empty(&rdev->fence_drv[ring].emitted)) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return -ENOENT;
+
+ r = radeon_wait_seq(fence->rdev, fence->seq, fence->ring, intr);
+ if (r) {
+ return r;
}
- fence = list_entry(rdev->fence_drv[ring].emitted.next,
- struct radeon_fence, list);
- radeon_fence_ref(fence);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- r = radeon_fence_wait(fence, false);
- radeon_fence_unref(&fence);
- return r;
+ fence->signaled = true;
+ return 0;
}
-int radeon_fence_wait_empty(struct radeon_device *rdev, int ring)
+int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
{
- unsigned long irq_flags;
- struct radeon_fence *fence;
- int r;
+ return radeon_wait_seq(rdev, rdev->fence_drv[ring].last_seq + 1ULL, ring, false);
+}
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
- if (!rdev->ring[ring].ready) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return -EBUSY;
- }
- if (list_empty(&rdev->fence_drv[ring].emitted)) {
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return 0;
- }
- fence = list_entry(rdev->fence_drv[ring].emitted.prev,
- struct radeon_fence, list);
- radeon_fence_ref(fence);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- r = radeon_fence_wait(fence, false);
- radeon_fence_unref(&fence);
- return r;
+int radeon_fence_wait_empty(struct radeon_device *rdev, int ring)
+{
+ return radeon_wait_seq(rdev, atomic64_read(&rdev->fence_drv[ring].seq), ring, false);
}
struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
@@ -332,47 +283,32 @@ void radeon_fence_unref(struct radeon_fence **fence)
void radeon_fence_process(struct radeon_device *rdev, int ring)
{
- unsigned long irq_flags;
bool wake;
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
- wake = radeon_fence_poll_locked(rdev, ring);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
+ wake = radeon_fence_poll(rdev, ring);
if (wake) {
wake_up_all(&rdev->fence_drv[ring].queue);
}
}
-int radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
+unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
{
- unsigned long irq_flags;
- int not_processed = 0;
-
- read_lock_irqsave(&rdev->fence_lock, irq_flags);
- if (!rdev->fence_drv[ring].initialized) {
- read_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return 0;
- }
+ uint64_t emitted;
- if (!list_empty(&rdev->fence_drv[ring].emitted)) {
- struct list_head *ptr;
- list_for_each(ptr, &rdev->fence_drv[ring].emitted) {
- /* count up to 3, that's enought info */
- if (++not_processed >= 3)
- break;
- }
+ radeon_fence_poll(rdev, ring);
+ emitted = atomic64_read(&rdev->fence_drv[ring].seq) - rdev->fence_drv[ring].last_seq;
+ /* to avoid 32bits warp around */
+ if (emitted > 0x10000000) {
+ emitted = 0x10000000;
}
- read_unlock_irqrestore(&rdev->fence_lock, irq_flags);
- return not_processed;
+ return (unsigned)emitted;
}
int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
{
- unsigned long irq_flags;
uint64_t index;
int r;
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg, 2);
if (rdev->wb.use_event) {
rdev->fence_drv[ring].scratch_reg = 0;
@@ -381,7 +317,6 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
r = radeon_scratch_get(rdev, &rdev->fence_drv[ring].scratch_reg, 2);
if (r) {
dev_err(rdev->dev, "fence failed to get scratch register\n");
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
return r;
}
index = RADEON_WB_SCRATCH_OFFSET +
@@ -392,9 +327,8 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
rdev->fence_drv[ring].gpu_addr = rdev->wb.gpu_addr + index;
radeon_fence_write(rdev, atomic64_read(&rdev->fence_drv[ring].seq), ring);
rdev->fence_drv[ring].initialized = true;
- DRM_INFO("fence driver on ring %d use gpu addr 0x%08Lx and cpu addr 0x%p\n",
+ dev_info(rdev->dev, "fence driver on ring %d use gpu addr 0x%08Lx and cpu addr 0x%p\n",
ring, rdev->fence_drv[ring].gpu_addr, rdev->fence_drv[ring].cpu_addr);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
return 0;
}
@@ -403,23 +337,20 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
rdev->fence_drv[ring].scratch_reg = -1;
rdev->fence_drv[ring].cpu_addr = NULL;
rdev->fence_drv[ring].gpu_addr = 0;
+ rdev->fence_drv[ring].last_activity = jiffies;
atomic64_set(&rdev->fence_drv[ring].seq, 0);
- INIT_LIST_HEAD(&rdev->fence_drv[ring].emitted);
- INIT_LIST_HEAD(&rdev->fence_drv[ring].signaled);
+ rdev->fence_drv[ring].last_seq = 0;
init_waitqueue_head(&rdev->fence_drv[ring].queue);
rdev->fence_drv[ring].initialized = false;
}
int radeon_fence_driver_init(struct radeon_device *rdev)
{
- unsigned long irq_flags;
int ring;
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
radeon_fence_driver_init_ring(rdev, ring);
}
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
if (radeon_debugfs_fence_init(rdev)) {
dev_err(rdev->dev, "fence debugfs file creation failed\n");
}
@@ -428,7 +359,6 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
void radeon_fence_driver_fini(struct radeon_device *rdev)
{
- unsigned long irq_flags;
int ring;
for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
@@ -436,9 +366,7 @@ void radeon_fence_driver_fini(struct radeon_device *rdev)
continue;
radeon_fence_wait_empty(rdev, ring);
wake_up_all(&rdev->fence_drv[ring].queue);
- write_lock_irqsave(&rdev->fence_lock, irq_flags);
radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg, 2);
- write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
rdev->fence_drv[ring].initialized = false;
}
}
@@ -453,7 +381,6 @@ static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
struct drm_info_node *node = (struct drm_info_node *)m->private;
struct drm_device *dev = node->minor->dev;
struct radeon_device *rdev = dev->dev_private;
- struct radeon_fence *fence;
int i;
for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -461,13 +388,10 @@ static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
continue;
seq_printf(m, "--- ring %d ---\n", i);
- seq_printf(m, "Last signaled fence 0x%016llx\n", radeon_fence_read(rdev, i));
- if (!list_empty(&rdev->fence_drv[i].emitted)) {
- fence = list_entry(rdev->fence_drv[i].emitted.prev,
- struct radeon_fence, list);
- seq_printf(m, "Last emitted fence %p with 0x%016llx\n",
- fence, fence->seq);
- }
+ seq_printf(m, "Last signaled 0x%016llx\n",
+ radeon_fence_read(rdev, i));
+ seq_printf(m, "Last emitted 0x%016lx\n",
+ atomic64_read(&rdev->fence_drv[i].seq));
}
return 0;
}
--
1.7.7.6
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