From c3eb54aad982d05493ab374a6f0d0a6831dd2c6e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 12 Oct 2019 08:01:36 +0100 Subject: [PATCH] drm/i915: Mark up "sentinel" requests Sometimes we want to emit a terminator request, a request that flushes the pipeline and allows no request to come after it. This can be used for a "preempt-to-idle" to ensure that upon processing the context-switch to that request, all other active contexts have been flushed. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191012070136.32058-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_lrc.c | 6 +++++- drivers/gpu/drm/i915/i915_request.h | 10 ++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 7f2d28bf9ea3..a07baeb897fe 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1208,7 +1208,8 @@ static bool can_merge_rq(const struct i915_request *prev, if (i915_request_completed(next)) return true; - if (unlikely(prev->flags ^ next->flags) & I915_REQUEST_NOPREEMPT) + if (unlikely((prev->flags ^ next->flags) & + (I915_REQUEST_NOPREEMPT | I915_REQUEST_SENTINEL))) return false; if (!can_merge_ctx(prev->hw_context, next->hw_context)) @@ -1659,6 +1660,9 @@ static void execlists_dequeue(struct intel_engine_cs *engine) if (last->hw_context == rq->hw_context) goto done; + if (i915_request_has_sentinel(last)) + goto done; + /* * If GVT overrides us we only ever submit * port[0], leaving port[1] empty. Note that we diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h index 6a95242b280d..96991d64759c 100644 --- a/drivers/gpu/drm/i915/i915_request.h +++ b/drivers/gpu/drm/i915/i915_request.h @@ -216,8 +216,9 @@ struct i915_request { unsigned long emitted_jiffies; unsigned long flags; -#define I915_REQUEST_WAITBOOST BIT(0) -#define I915_REQUEST_NOPREEMPT BIT(1) +#define I915_REQUEST_WAITBOOST BIT(0) +#define I915_REQUEST_NOPREEMPT BIT(1) +#define I915_REQUEST_SENTINEL BIT(2) /** timeline->request entry for this request */ struct list_head link; @@ -440,6 +441,11 @@ static inline bool i915_request_has_nopreempt(const struct i915_request *rq) return unlikely(rq->flags & I915_REQUEST_NOPREEMPT); } +static inline bool i915_request_has_sentinel(const struct i915_request *rq) +{ + return unlikely(rq->flags & I915_REQUEST_SENTINEL); +} + static inline struct intel_timeline * i915_request_timeline(struct i915_request *rq) {