From patchwork Thu May 20 07:35:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Auld X-Patchwork-Id: 444633 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F73CC433ED for ; Thu, 20 May 2021 07:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3417060FE5 for ; Thu, 20 May 2021 07:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229953AbhETHgz (ORCPT ); Thu, 20 May 2021 03:36:55 -0400 Received: from mga07.intel.com ([134.134.136.100]:17157 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbhETHgy (ORCPT ); Thu, 20 May 2021 03:36:54 -0400 IronPort-SDR: 0NUkfEJhUQ85UDegfxOe8YC/aeMnIijd2aDul4tq9cqSnd5eUeoJQmn+3MKPesFdIZ93P+nQC5 NO/HO2lzaB/g== X-IronPort-AV: E=McAfee;i="6200,9189,9989"; a="265080227" X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="265080227" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2021 00:35:32 -0700 IronPort-SDR: rPkLRbszIc0XjAuyx4Wb4er9vrg5UvqyzlBeQ6CfhgzNVSPQmJyE/LAIAoE4K4FU5W5bSk6gW+ 6Fkz2JQ0tYMQ== X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="543237768" Received: from nyeong-mobl.gar.corp.intel.com (HELO mwauld-desk1.intel.com) ([10.249.70.38]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2021 00:35:28 -0700 From: Matthew Auld To: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, Chris Wilson , Tvrtko Ursulin , Chintan M Patel , Andi Shyti , stable@vger.kernel.org Subject: [PATCH] drm/i915: Use DRIVER_NAME for tracing unattached requests Date: Thu, 20 May 2021 08:35:14 +0100 Message-Id: <20210520073514.314893-1-matthew.auld@intel.com> X-Mailer: git-send-email 2.26.3 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chris Wilson The first tracepoint for a request is trace_dma_fence_init called before we have associated the request with a device. The tracepoint uses fence->ops->get_driver_name() as a pretty name, and as we try to report the device name this oopses as it is then NULL. Support the early tracepoint by reporting the DRIVER_NAME instead of the actual device name. Note that rq->engine remains during the course of request recycling (SLAB_TYPESAFE_BY_RCU). For the physical engines, the pointer remains valid, however a virtual engine may be destroyed after the request is retired. If we process a preempt-to-busy completed request along the virtual engine, we should make sure we mark the request as no longer belonging to the virtual engine to remove the dangling pointers from the tracepoint. Fixes: 855e39e65cfc ("drm/i915: Initialise basic fence before acquiring seqno") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Chintan M Patel Cc: Andi Shyti Cc: # v5.7+ Signed-off-by: Matthew Auld --- .../drm/i915/gt/intel_execlists_submission.c | 20 ++++++++++++++----- drivers/gpu/drm/i915/i915_request.c | 7 ++++++- 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index de124870af44..75604e927d34 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -3249,6 +3249,18 @@ static struct list_head *virtual_queue(struct virtual_engine *ve) return &ve->base.execlists.default_priolist.requests; } +static void +virtual_submit_completed(struct virtual_engine *ve, struct i915_request *rq) +{ + GEM_BUG_ON(!__i915_request_is_complete(rq)); + GEM_BUG_ON(rq->engine != &ve->base); + + __i915_request_submit(rq); + + /* Remove the dangling pointer to the stale virtual engine */ + WRITE_ONCE(rq->engine, ve->siblings[0]); +} + static void rcu_virtual_context_destroy(struct work_struct *wrk) { struct virtual_engine *ve = @@ -3265,8 +3277,7 @@ static void rcu_virtual_context_destroy(struct work_struct *wrk) old = fetch_and_zero(&ve->request); if (old) { - GEM_BUG_ON(!__i915_request_is_complete(old)); - __i915_request_submit(old); + virtual_submit_completed(ve, old); i915_request_put(old); } @@ -3538,13 +3549,12 @@ static void virtual_submit_request(struct i915_request *rq) /* By the time we resubmit a request, it may be completed */ if (__i915_request_is_complete(rq)) { - __i915_request_submit(rq); + virtual_submit_completed(ve, rq); goto unlock; } if (ve->request) { /* background completion from preempt-to-busy */ - GEM_BUG_ON(!__i915_request_is_complete(ve->request)); - __i915_request_submit(ve->request); + virtual_submit_completed(ve, ve->request); i915_request_put(ve->request); } diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 970d8f4986bb..aa124adb1051 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -61,7 +61,12 @@ static struct i915_global_request { static const char *i915_fence_get_driver_name(struct dma_fence *fence) { - return dev_name(to_request(fence)->engine->i915->drm.dev); + struct i915_request *rq = to_request(fence); + + if (unlikely(!rq->engine)) /* not yet attached to any device */ + return DRIVER_NAME; + + return dev_name(rq->engine->i915->drm.dev); } static const char *i915_fence_get_timeline_name(struct dma_fence *fence)