From 09975b861aa0c5cc0f1a6f9543807f344c4c12ae Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 9 Jul 2019 10:12:33 +0100 Subject: [PATCH] drm/i915/execlists: Disable preemption under GVT 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 Cc: Zhenyu Wang Cc: Xiaolin Zhang Cc: Tvrtko Ursulin Cc: Mika Kuoppala Acked-by: Zhenyu Wang Link: https://patchwork.freedesktop.org/patch/msgid/20190709091233.8573-1-chris@chris-wilson.co.uk --- 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 9570659aa360..c0bc9cb7f228 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -829,6 +829,8 @@ 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 @@ -847,8 +849,6 @@ 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 9e0992498087..a220575a69bc 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -306,6 +306,9 @@ 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. * @@ -904,6 +907,9 @@ 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; @@ -2656,7 +2662,8 @@ 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); @@ -2680,7 +2687,8 @@ 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); @@ -2728,10 +2736,11 @@ 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) @@ -3419,7 +3428,6 @@ 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 @@ -3516,8 +3524,12 @@ 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 6b6cea76cc8b..60f27e52d267 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; -- 2.30.2