From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 8 Mar 2018 14:07:32 +0000
Subject: drm/i915: Remove the impedance mismatch around
intel_engine_enable_signaling
Git-commit: 6f9ec414ec47eea3f3e2c5ad4c67b4265bbff2a3
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
There is some redundancy between dma_fence->ops->enable_signaling (via
i915_fence_enable_signaling) and our backend,
intel_engine_enable_signaling() in that both levels recheck the fence
status multiple times. If we convert intel_engine_enable_signaling() to
return the information desired by dma_fence->ops->enable_signaling, we
can reduce i915_fence_enable_signaling to a simple stub and avoid
trying to reinterpret the same information.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180308140732.25090-1-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_request.c | 6 +-----
drivers/gpu/drm/i915/intel_breadcrumbs.c | 21 +++++++++++++--------
drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +-
3 files changed, 15 insertions(+), 14 deletions(-)
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -59,11 +59,7 @@ static bool i915_fence_signaled(struct d
static bool i915_fence_enable_signaling(struct dma_fence *fence)
{
- if (i915_fence_signaled(fence))
- return false;
-
- intel_engine_enable_signaling(to_request(fence), true);
- return !i915_fence_signaled(fence);
+ return intel_engine_enable_signaling(to_request(fence), true);
}
static signed long i915_fence_wait(struct dma_fence *fence,
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -730,10 +730,11 @@ static void insert_signal(struct intel_b
list_add(&request->signaling.link, &iter->signaling.link);
}
-void intel_engine_enable_signaling(struct i915_request *request, bool wakeup)
+bool intel_engine_enable_signaling(struct i915_request *request, bool wakeup)
{
struct intel_engine_cs *engine = request->engine;
struct intel_breadcrumbs *b = &engine->breadcrumbs;
+ struct intel_wait *wait = &request->signaling.wait;
u32 seqno;
/*
@@ -750,12 +751,12 @@ void intel_engine_enable_signaling(struc
seqno = i915_request_global_seqno(request);
if (!seqno) /* will be enabled later upon execution */
- return;
+ return true;
- GEM_BUG_ON(request->signaling.wait.seqno);
- request->signaling.wait.tsk = b->signaler;
- request->signaling.wait.request = request;
- request->signaling.wait.seqno = seqno;
+ GEM_BUG_ON(wait->seqno);
+ wait->tsk = b->signaler;
+ wait->request = request;
+ wait->seqno = seqno;
/*
* Add ourselves into the list of waiters, but registering our
@@ -768,11 +769,15 @@ void intel_engine_enable_signaling(struc
*/
spin_lock(&b->rb_lock);
insert_signal(b, request, seqno);
- wakeup &= __intel_engine_add_wait(engine, &request->signaling.wait);
+ wakeup &= __intel_engine_add_wait(engine, wait);
spin_unlock(&b->rb_lock);
- if (wakeup)
+ if (wakeup) {
wake_up_process(b->signaler);
+ return !intel_wait_complete(wait);
+ }
+
+ return true;
}
void intel_engine_cancel_signaling(struct i915_request *request)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -939,7 +939,7 @@ bool intel_engine_add_wait(struct intel_
struct intel_wait *wait);
void intel_engine_remove_wait(struct intel_engine_cs *engine,
struct intel_wait *wait);
-void intel_engine_enable_signaling(struct i915_request *request, bool wakeup);
+bool intel_engine_enable_signaling(struct i915_request *request, bool wakeup);
void intel_engine_cancel_signaling(struct i915_request *request);
static inline bool intel_engine_has_waiter(const struct intel_engine_cs *engine)