[RFC 28/39] drm/i915: Connecting execbuff fences to scheduler

John.C.Harrison
2015-07-17T14:34:24Z

The scheduler now supports sync framework fences being associated with
batch buffers. The execbuff IOCTL allows such fences to be passed in
from user land. This patch wires the two together so that the IOCTL no
longer needs to stall on the fence immediately. Instead the stall is
now swallowed by the scheduler's scheduling algorithm.

For: VIZ-1587
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 21 ++++++++++++++++++++-
drivers/gpu/drm/i915/i915_scheduler.c | 3 +++
drivers/gpu/drm/i915/i915_scheduler.h | 5 +++++
3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 1642701..1325b19 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1612,7 +1612,9 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
/*
* Without a GPU scheduler, any fence waits must be done up front.
*/
- if (args->flags & I915_EXEC_WAIT_FENCE) {
+ if ((args->flags & I915_EXEC_WAIT_FENCE) &&
+ (i915.scheduler_override & i915_so_direct_submit))
+ {
ret = i915_early_fence_wait(ring, fd_fence_wait);
if (ret < 0)
return ret;
@@ -1799,6 +1801,18 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
params->ctx = ctx;

#ifdef CONFIG_SYNC
+ if (args->flags & I915_EXEC_WAIT_FENCE) {
+ if (fd_fence_wait < 0) {
+ DRM_ERROR("Wait fence for ring %d has invalid id %d\n",
+ (int) ring->id, fd_fence_wait);
+ } else {
+ params->fence_wait = sync_fence_fdget(fd_fence_wait);
+ if (params->fence_wait == NULL)
+ DRM_ERROR("Invalid wait fence %d\n",
+ fd_fence_wait);
+ }
+ }
+
if (args->flags & I915_EXEC_CREATE_FENCE) {
/*
* Caller has requested a sync fence.
@@ -1865,6 +1879,11 @@ err:
i915_gem_context_unreference(params->ctx);
}

+#ifdef CONFIG_SYNC
+ if (params->fence_wait)
+ sync_fence_put(params->fence_wait);
+#endif
+
/*
* If the request was created but not successfully submitted then it
* must be freed again. If it was submitted then it is being tracked
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index 19577c9..66dbc20 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -977,6 +977,9 @@ static int i915_scheduler_pop_from_queue_locked(struct intel_engine_cs *ring,
signalled = atomic_read(&node->params.fence_wait->status) != 0;
else
signalled = true;
+
+ if (!signalled)
+ signalled = i915_safe_to_ignore_fence(ring, node->params.fence_wait);
#endif // CONFIG_SYNC

has_local = false;
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 8ca4b4b..3f94512 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -110,6 +110,11 @@ int i915_scheduler_queue_execbuffer(struct i915_scheduler_queue_entry *q
int i915_scheduler_handle_irq(struct intel_engine_cs *ring);
void i915_scheduler_kill_all(struct drm_device *dev);
void i915_gem_scheduler_work_handler(struct work_struct *work);
+#ifdef CONFIG_SYNC
+struct drm_i915_gem_request *i915_scheduler_find_by_sync_value(struct intel_engine_cs *ring,
+ struct intel_context *ctx,
+ uint32_t sync_value);
+#endif
int i915_scheduler_flush(struct intel_engine_cs *ring, bool is_locked);
int i915_scheduler_flush_request(struct drm_i915_gem_request *req,
bool is_locked);