Preempt-to-busy uses a GPU semaphore to enforce an idle-barrier across
preemption, but mediated gvt does not fully support semaphores.
v2: Fiddle around with the flags and settle on using has-semaphores for
the core bits so that we retain the ability to preempt our own
semaphores.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Cc: Xiaolin Zhang <xiaolin.zhang@xxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 4 ++--
drivers/gpu/drm/i915/gt/intel_lrc.c | 24 +++++++++++++++++------
drivers/gpu/drm/i915/gt/selftest_lrc.c | 6 ++++++
3 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 56310812da21..614ed8c488ef 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -825,6 +825,8 @@ int intel_engine_init_common(struct intel_engine_cs *engine)
struct drm_i915_private *i915 = engine->i915;
int ret;
+ engine->set_default_submission(engine);
+
/* We may need to do things with the shrinker which
* require us to immediately switch back to the default
* context. This can cause a problem as pinning the
@@ -852,8 +854,6 @@ int intel_engine_init_common(struct intel_engine_cs *engine)
engine->emit_fini_breadcrumb_dw = ret;
- engine->set_default_submission(engine);
-
return 0;
err_unpin:
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 558a5850de3c..ef36f4b5e212 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -295,6 +295,9 @@ static inline bool need_preempt(const struct intel_engine_cs *engine,
{
int last_prio;
+ if (!intel_engine_has_semaphores(engine))
+ return false;
+
/*
* Check if the current priority hint merits a preemption attempt.
*
@@ -893,6 +896,9 @@ need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
{
int hint;
+ if (!intel_engine_has_semaphores(engine))
+ return false;
+
if (list_is_last(&rq->sched.link, &engine->active.requests))
return false;
@@ -2634,7 +2640,8 @@ static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
*cs++ = MI_USER_INTERRUPT;
*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
- cs = emit_preempt_busywait(request, cs);
+ if (intel_engine_has_semaphores(request->engine))
+ cs = emit_preempt_busywait(request, cs);
request->tail = intel_ring_offset(request, cs);
assert_ring_tail_valid(request->ring, request->tail);
@@ -2658,7 +2665,8 @@ static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
*cs++ = MI_USER_INTERRUPT;
*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
- cs = emit_preempt_busywait(request, cs);
+ if (intel_engine_has_semaphores(request->engine))
+ cs = emit_preempt_busywait(request, cs);
request->tail = intel_ring_offset(request, cs);
assert_ring_tail_valid(request->ring, request->tail);
@@ -2706,10 +2714,11 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
engine->unpark = NULL;
engine->flags |= I915_ENGINE_SUPPORTS_STATS;
- if (!intel_vgpu_active(engine->i915))
+ if (!intel_vgpu_active(engine->i915)) {
engine->flags |= I915_ENGINE_HAS_SEMAPHORES;
- if (HAS_LOGICAL_RING_PREEMPTION(engine->i915))
- engine->flags |= I915_ENGINE_HAS_PREEMPTION;
+ if (HAS_LOGICAL_RING_PREEMPTION(engine->i915))
+ engine->flags |= I915_ENGINE_HAS_PREEMPTION;
+ }
}
static void execlists_destroy(struct intel_engine_cs *engine)
@@ -3399,7 +3408,6 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
ve->base.class = OTHER_CLASS;
ve->base.uabi_class = I915_ENGINE_CLASS_INVALID;
ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
- ve->base.flags = I915_ENGINE_IS_VIRTUAL;
/*
* The decision on whether to submit a request using semaphores
@@ -3496,8 +3504,12 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
ve->base.emit_fini_breadcrumb = sibling->emit_fini_breadcrumb;
ve->base.emit_fini_breadcrumb_dw =
sibling->emit_fini_breadcrumb_dw;
+
+ ve->base.flags = sibling->flags;
}
+ ve->base.flags |= I915_ENGINE_IS_VIRTUAL;
+
return &ve->context;
err_put:
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index fe4e15f9ba9d..a13f06ba984b 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -269,6 +269,9 @@ static int live_timeslice_preempt(void *arg)
enum intel_engine_id id;
for_each_engine(engine, i915, id) {
+ if (!intel_engine_has_preemption(engine))
+ continue;
+
memset(vaddr, 0, PAGE_SIZE);
err = slice_semaphore_queue(engine, vma, count);
@@ -354,6 +357,9 @@ static int live_busywait_preempt(void *arg)
struct igt_live_test t;
u32 *cs;
+ if (!intel_engine_has_preemption(engine))
+ continue;
+
if (!intel_engine_can_store_dword(engine))
continue;
--
2.22.0
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
