From patchwork Tue Jan 17 21:36:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Harrison X-Patchwork-Id: 13105081 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 45576C54E76 for ; Tue, 17 Jan 2023 21:37:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7425710E5E9; Tue, 17 Jan 2023 21:37:01 +0000 (UTC) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id EB56C10E088; Tue, 17 Jan 2023 21:36:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673991414; x=1705527414; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9zCLjq2fwuiIkrwTjl39OJ+CMLrbrn0iy5u/pvPh2sA=; b=nQwJd4xb9AkEZfLslL5KaW5vWNExaPzTZfjKlF5IY86lokUCUed7hPrC NT28nSsdcDHVA879Gc0pd/ekv2P+pFkanHYWAOhuxmXGKxSeDqnjA9xfJ oC3Y6483VYjQSR2AyMCykw0j/SQNAM5Bz6iDA7KXO7Y95gQlUNXfy7NbU sAt+amJD+UoZg/CYHDSew7lY9Nxn+h4mCKcg7GlabjTELMLafIDpdi8jZ CMgncPV01ECWqTgcvqabopvE0Qg7t79A1jQFIi8A9JO6jpxIsew+DORl/ 5pNiUflj+03213493CDIvsJWzrlCAZh08jowiqOq7bD69+pRTqZiOa11g g==; X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="312696224" X-IronPort-AV: E=Sophos;i="5.97,224,1669104000"; d="scan'208";a="312696224" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jan 2023 13:36:53 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="988285020" X-IronPort-AV: E=Sophos;i="5.97,224,1669104000"; d="scan'208";a="988285020" Received: from relo-linux-5.jf.intel.com ([10.165.21.152]) by fmsmga005.fm.intel.com with ESMTP; 17 Jan 2023 13:36:52 -0800 From: John.C.Harrison@Intel.com To: Intel-GFX@Lists.FreeDesktop.Org Subject: [PATCH v2 1/5] drm/i915: Fix request locking during error capture & debugfs dump Date: Tue, 17 Jan 2023 13:36:26 -0800 Message-Id: <20230117213630.2897570-2-John.C.Harrison@Intel.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230117213630.2897570-1-John.C.Harrison@Intel.com> References: <20230117213630.2897570-1-John.C.Harrison@Intel.com> MIME-Version: 1.0 Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matthew Brost , Tvrtko Ursulin , Andy Shevchenko , Michael Cheng , Aravind Iddamsetty , Alan Previn , Umesh Nerlige Ramappa , intel-gfx@lists.freedesktop.org, Lucas De Marchi , Chris Wilson , Bruce Chang , Daniele Ceraolo Spurio , DRI-Devel@Lists.FreeDesktop.Org, Andrzej Hajda , Rodrigo Vivi , Tejas Upadhyay , John Harrison , Matthew Auld Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: John Harrison When GuC support was added to error capture, the locking around the request object was broken. Fix it up. The context based search manages the spinlocking around the search internally. So it needs to grab the reference count internally as well. The execlist only request based search relies on external locking, so it needs an external reference count. So no change to that code itself but the context version does change. The only other caller is the code for dumping engine state to debugfs. That code wasn't previously getting an explicit reference at all as it does everything while holding the execlist specific spinlock. So that needs updaing as well as that spinlock doesn't help when using GuC submission. Rather than trying to conditionally get/put depending on submission model, just change it to always do the get/put. In addition, intel_guc_find_hung_context() was not acquiring the correct spinlock before searching the request list. So fix that up too. Fixes: dc0dad365c5e ("drm/i915/guc: Fix for error capture after full GPU reset with GuC") Fixes: 573ba126aef3 ("drm/i915/guc: Capture error state on context reset") Cc: Matthew Brost Cc: John Harrison Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: Tvrtko Ursulin Cc: Daniele Ceraolo Spurio Cc: Andrzej Hajda Cc: Chris Wilson Cc: Matthew Auld Cc: Matt Roper Cc: Umesh Nerlige Ramappa Cc: Michael Cheng Cc: Lucas De Marchi Cc: Tejas Upadhyay Cc: Andy Shevchenko Cc: Aravind Iddamsetty Cc: Alan Previn Cc: Bruce Chang Cc: intel-gfx@lists.freedesktop.org Signed-off-by: John Harrison --- drivers/gpu/drm/i915/gt/intel_context.c | 1 + drivers/gpu/drm/i915/gt/intel_engine_cs.c | 7 ++++++- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 11 +++++++++++ drivers/gpu/drm/i915/i915_gpu_error.c | 5 ++--- 4 files changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index e94365b08f1ef..df64cf1954c1d 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -552,6 +552,7 @@ struct i915_request *intel_context_find_active_request(struct intel_context *ce) active = rq; } + active = i915_request_get_rcu(active); spin_unlock_irqrestore(&parent->guc_state.lock, flags); return active; diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 922f1bb22dc68..517d1fb7ae333 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -2236,10 +2236,13 @@ static void engine_dump_active_requests(struct intel_engine_cs *engine, struct d guc = intel_uc_uses_guc_submission(&engine->gt->uc); if (guc) { ce = intel_engine_get_hung_context(engine); - if (ce) + if (ce) { + /* This will reference count the request (if found) */ hung_rq = intel_context_find_active_request(ce); + } } else { hung_rq = intel_engine_execlist_find_hung_request(engine); + hung_rq = i915_request_get_rcu(hung_rq); } if (hung_rq) @@ -2250,6 +2253,8 @@ static void engine_dump_active_requests(struct intel_engine_cs *engine, struct d else intel_engine_dump_active_requests(&engine->sched_engine->requests, hung_rq, m); + if (hung_rq) + i915_request_put(hung_rq); } void intel_engine_dump(struct intel_engine_cs *engine, 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 b436dd7f12e42..3b34a82d692be 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -4820,6 +4820,8 @@ void intel_guc_find_hung_context(struct intel_engine_cs *engine) xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) { + bool found; + if (!kref_get_unless_zero(&ce->ref)) continue; @@ -4836,10 +4838,18 @@ void intel_guc_find_hung_context(struct intel_engine_cs *engine) goto next; } + found = false; + spin_lock(&ce->guc_state.lock); list_for_each_entry(rq, &ce->guc_state.requests, sched.link) { if (i915_test_request_state(rq) != I915_REQUEST_ACTIVE) continue; + found = true; + break; + } + spin_unlock(&ce->guc_state.lock); + + if (found) { intel_engine_set_hung_context(engine, ce); /* Can only cope with one hang at a time... */ @@ -4847,6 +4857,7 @@ void intel_guc_find_hung_context(struct intel_engine_cs *engine) xa_lock(&guc->context_lookup); goto done; } + next: intel_context_put(ce); xa_lock(&guc->context_lookup); diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 9d5d5a397b64e..4107a0dfcca7d 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -1607,6 +1607,7 @@ capture_engine(struct intel_engine_cs *engine, ce = intel_engine_get_hung_context(engine); if (ce) { intel_engine_clear_hung_context(engine); + /* This will reference count the request (if found) */ rq = intel_context_find_active_request(ce); if (!rq || !i915_request_started(rq)) goto no_request_capture; @@ -1618,13 +1619,11 @@ capture_engine(struct intel_engine_cs *engine, if (!intel_uc_uses_guc_submission(&engine->gt->uc)) { spin_lock_irqsave(&engine->sched_engine->lock, flags); rq = intel_engine_execlist_find_hung_request(engine); + rq = i915_request_get_rcu(rq); spin_unlock_irqrestore(&engine->sched_engine->lock, flags); } } - if (rq) - rq = i915_request_get_rcu(rq); - if (!rq) goto no_request_capture;