Modifying a remote context requires careful serialisation with requests on that context, and that serialisation requires us to take their timeline->mutex. Make it so.
Note that while struct_mutex rules, we can't create more than one request in parallel, but that age is soon coming to an end. v2: Though it doesn't affect the current users, contexts may share timelines so check if we already hold the right mutex. Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 16 ++------- drivers/gpu/drm/i915/gt/intel_context.c | 38 +++++++++++++++++++++ drivers/gpu/drm/i915/gt/intel_context.h | 3 ++ drivers/gpu/drm/i915/i915_perf.c | 7 +--- 4 files changed, 44 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index 6b5644d5a99b..0551cea321cc 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -1174,20 +1174,8 @@ gen8_modify_rpcs(struct intel_context *ce, struct intel_sseu sseu) if (IS_ERR(rq)) return PTR_ERR(rq); - /* Queue this switch after all other activity by this context. */ - ret = i915_active_request_set(&ce->ring->timeline->last_request, rq); - if (ret) - goto out_add; - - /* - * Guarantee context image and the timeline remains pinned until the - * modifying request is retired by setting the ce activity tracker. - * - * But we only need to take one pin on the account of it. Or in other - * words transfer the pinned ce object to tracked active request. - */ - GEM_BUG_ON(i915_active_is_idle(&ce->active)); - ret = i915_active_ref(&ce->active, rq->fence.context, rq); + /* Serialise with the remote context */ + ret = intel_context_prepare_remote_request(ce, rq); if (ret) goto out_add; diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index f012ec898aba..8938f798608b 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -239,6 +239,44 @@ void intel_context_exit_engine(struct intel_context *ce) intel_engine_pm_put(ce->engine); } +int intel_context_prepare_remote_request(struct intel_context *ce, + struct i915_request *rq) +{ + struct intel_timeline *tl = ce->ring->timeline; + int err; + + /* Only suitable for use in remotely modifying this context */ + GEM_BUG_ON(rq->hw_context == ce); + + if (rq->timeline != tl) { /* beware timeline sharing */ + err = mutex_lock_interruptible_nested(&tl->mutex, + SINGLE_DEPTH_NESTING); + if (err) + return err; + } + lockdep_assert_held(&tl->mutex); + + /* Queue this switch after all other activity by this context. */ + err = i915_active_request_set(&tl->last_request, rq); + if (err) + goto unlock; + + /* + * Guarantee context image and the timeline remains pinned until the + * modifying request is retired by setting the ce activity tracker. + * + * But we only need to take one pin on the account of it. Or in other + * words transfer the pinned ce object to tracked active request. + */ + GEM_BUG_ON(i915_active_is_idle(&ce->active)); + err = i915_active_ref(&ce->active, rq->fence.context, rq); + +unlock: + if (rq->timeline != tl) + mutex_unlock(&tl->mutex); + return err; +} + struct i915_request *intel_context_create_request(struct intel_context *ce) { struct i915_request *rq; diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index 40cd8320fcc3..b41c610c2ce6 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -139,6 +139,9 @@ static inline void intel_context_timeline_unlock(struct intel_context *ce) mutex_unlock(&ce->ring->timeline->mutex); } +int intel_context_prepare_remote_request(struct intel_context *ce, + struct i915_request *rq); + struct i915_request *intel_context_create_request(struct intel_context *ce); #endif /* __INTEL_CONTEXT_H__ */ diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 78cb9ec8866c..58a71efc25db 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -1768,12 +1768,7 @@ static int gen8_modify_context(struct intel_context *ce, return PTR_ERR(rq); /* Serialise with the remote context */ - err = i915_active_request_set(&ce->ring->timeline->last_request, rq); - if (err) - goto out_add; - - /* Keep the remote context alive until after we finish editing */ - err = i915_active_ref(&ce->active, rq->fence.context, rq); + err = intel_context_prepare_remote_request(ce, rq); if (err) goto out_add; -- 2.22.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
