From 5bb61f14865110ef894d571e76684ade5bf24b5f Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Thu, 9 Sep 2021 09:47:34 -0700 Subject: [PATCH] drm/i915/guc: Don't touch guc_state.sched_state without a lock Before we did some clever tricks to not use the a lock when touching guc_state.sched_state in certain cases. Don't do that, enforce the use of the lock. v2: (kernel test robo ) - Add __maybe_unused to sched_state_is_init() v3: rebase after the unused code path removal has been moved to an earlier patch. Signed-off-by: Matthew Brost Reported-by: kernel test robot Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: John Harrison Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-14-matthew.brost@intel.com --- .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 22 ++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index e036a171ff179..ca73128d7b4d5 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -151,11 +151,23 @@ static inline void clr_context_registered(struct intel_context *ce) static inline void init_sched_state(struct intel_context *ce) { - /* Only should be called from guc_lrc_desc_pin() */ + lockdep_assert_held(&ce->guc_state.lock); atomic_set(&ce->guc_sched_state_no_lock, 0); ce->guc_state.sched_state &= SCHED_STATE_BLOCKED_MASK; } +__maybe_unused +static bool sched_state_is_init(struct intel_context *ce) +{ + /* + * XXX: Kernel contexts can have SCHED_STATE_NO_LOCK_REGISTERED after + * suspend. + */ + return !(atomic_read(&ce->guc_sched_state_no_lock) & + ~SCHED_STATE_NO_LOCK_REGISTERED) && + !(ce->guc_state.sched_state &= ~SCHED_STATE_BLOCKED_MASK); +} + static inline bool context_wait_for_deregister_to_register(struct intel_context *ce) { @@ -166,7 +178,7 @@ context_wait_for_deregister_to_register(struct intel_context *ce) static inline void set_context_wait_for_deregister_to_register(struct intel_context *ce) { - /* Only should be called from guc_lrc_desc_pin() without lock */ + lockdep_assert_held(&ce->guc_state.lock); ce->guc_state.sched_state |= SCHED_STATE_WAIT_FOR_DEREGISTER_TO_REGISTER; } @@ -607,9 +619,7 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) bool pending_disable, pending_enable, deregister, destroyed, banned; xa_for_each(&guc->context_lookup, index, ce) { - /* Flush context */ spin_lock_irqsave(&ce->guc_state.lock, flags); - spin_unlock_irqrestore(&ce->guc_state.lock, flags); /* * Once we are at this point submission_disabled() is guaranteed @@ -625,6 +635,8 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) banned = context_banned(ce); init_sched_state(ce); + spin_unlock_irqrestore(&ce->guc_state.lock, flags); + if (pending_enable || destroyed || deregister) { decr_outstanding_submission_g2h(guc); if (deregister) @@ -1324,6 +1336,7 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop) int ret = 0; GEM_BUG_ON(!engine->mask); + GEM_BUG_ON(!sched_state_is_init(ce)); /* * Ensure LRC + CT vmas are is same region as write barrier is done @@ -1352,7 +1365,6 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop) desc->priority = ce->guc_prio; desc->context_flags = CONTEXT_REGISTRATION_FLAG_KMD; guc_context_policy_init(engine, desc); - init_sched_state(ce); /* * The context_lookup xarray is used to determine if the hardware -- 2.39.5