From patchwork Thu Jul 18 07:00:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11048567 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F8D61800 for ; Thu, 18 Jul 2019 07:00:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F30D206AF for ; Thu, 18 Jul 2019 07:00:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02CFB22A6F; Thu, 18 Jul 2019 07:00:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9564A206AF for ; Thu, 18 Jul 2019 07:00:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 469226E31C; Thu, 18 Jul 2019 07:00:43 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id B8B176E319 for ; Thu, 18 Jul 2019 07:00:40 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 17390400-1500050 for multiple; Thu, 18 Jul 2019 08:00:39 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 18 Jul 2019 08:00:24 +0100 Message-Id: <20190718070024.21781-20-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190718070024.21781-1-chris@chris-wilson.co.uk> References: <20190718070024.21781-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 20/20] drm/i915/gt: Mark context->active_count as protected by timeline->mutex X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We use timeline->mutex to protect modifications to context->active_count, and the associated enable/disable callbacks. Due to complications with engine-pm barrier there is a path where we used a "superlock" to provide serialised protect and so could not unconditionally assert with lockdep that it was always held. However, we can mark the mutex as taken (noting that we may be nested underneath ourselves) which means we can be reassured the right timeline->mutex is always treated as held and let lockdep roam free. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/gt/intel_context.h | 3 +++ drivers/gpu/drm/i915/gt/intel_context_types.h | 2 +- drivers/gpu/drm/i915/gt/intel_engine_pm.c | 12 ++++++++++++ drivers/gpu/drm/i915/gt/intel_timeline.c | 4 ++++ 4 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index fc7859f506c2..020139bfe3a9 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -89,17 +89,20 @@ void intel_context_exit_engine(struct intel_context *ce); static inline void intel_context_enter(struct intel_context *ce) { + lockdep_assert_held(&ce->ring->timeline->mutex); if (!ce->active_count++) ce->ops->enter(ce); } static inline void intel_context_mark_active(struct intel_context *ce) { + lockdep_assert_held(&ce->ring->timeline->mutex); ++ce->active_count; } static inline void intel_context_exit(struct intel_context *ce) { + lockdep_assert_held(&ce->ring->timeline->mutex); GEM_BUG_ON(!ce->active_count); if (!--ce->active_count) ce->ops->exit(ce); diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index 68a7e979b1a9..92afc207ec80 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -55,7 +55,7 @@ struct intel_context { u32 *lrc_reg_state; u64 lrc_desc; - unsigned int active_count; /* notionally protected by timeline->mutex */ + unsigned int active_count; /* protected by timeline->mutex */ atomic_t pin_count; struct mutex pin_mutex; /* guards pinning and associated on-gpuing */ diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c index 76c828d11b05..1218b7d53b88 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c @@ -59,6 +59,16 @@ void intel_engine_park(struct intel_engine_cs *engine) } } +static inline void __timeline_mark_lock(struct intel_context *ce) +{ + mutex_acquire(&ce->ring->timeline->mutex.dep_map, 2, 0, _THIS_IP_); +} + +static inline void __timeline_mark_unlock(struct intel_context *ce) +{ + mutex_release(&ce->ring->timeline->mutex.dep_map, 0, _THIS_IP_); +} + static bool switch_to_kernel_context(struct intel_engine_cs *engine) { struct i915_request *rq; @@ -83,6 +93,7 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine) * retiring the last request, thus all rings should be empty and * all timelines idle. */ + __timeline_mark_lock(engine->kernel_context); rq = __i915_request_create(engine->kernel_context, GFP_NOWAIT); if (IS_ERR(rq)) /* Context switch failed, hope for the best! Maybe reset? */ @@ -94,6 +105,7 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine) i915_request_add_barriers(rq); __i915_request_commit(rq); + __timeline_mark_unlock(engine->kernel_context); return false; } diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c index 7b476cd55dac..eafd94d5e211 100644 --- a/drivers/gpu/drm/i915/gt/intel_timeline.c +++ b/drivers/gpu/drm/i915/gt/intel_timeline.c @@ -338,6 +338,8 @@ void intel_timeline_enter(struct intel_timeline *tl) { struct intel_gt_timelines *timelines = &tl->gt->timelines; + lockdep_assert_held(&tl->mutex); + GEM_BUG_ON(!atomic_read(&tl->pin_count)); if (tl->active_count++) return; @@ -352,6 +354,8 @@ void intel_timeline_exit(struct intel_timeline *tl) { struct intel_gt_timelines *timelines = &tl->gt->timelines; + lockdep_assert_held(&tl->mutex); + GEM_BUG_ON(!tl->active_count); if (--tl->active_count) return;