From patchwork Wed Jul 10 06:44:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11037973 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 978FD14C0 for ; Wed, 10 Jul 2019 06:45:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 883EB288FD for ; Wed, 10 Jul 2019 06:45:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7C5D628901; Wed, 10 Jul 2019 06:45:25 +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 20033288FD for ; Wed, 10 Jul 2019 06:45:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1A945899F0; Wed, 10 Jul 2019 06:45:20 +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 6C1E5899E9 for ; Wed, 10 Jul 2019 06:45:17 +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 17193826-1500050 for multiple; Wed, 10 Jul 2019 07:45:05 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 10 Jul 2019 07:44:53 +0100 Message-Id: <20190710064454.682-13-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190710064454.682-1-chris@chris-wilson.co.uk> References: <20190710064454.682-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 13/14] 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 ++++++++++++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index 8429a97a3911..02bab98f2c72 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -88,17 +88,20 @@ 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 4c0e211c715d..c00419e38a77 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -53,7 +53,7 @@ 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 fe9f9eaffe88..34376d33e4ca 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c @@ -58,6 +58,16 @@ 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; @@ -82,6 +92,7 @@ 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? */ @@ -93,6 +104,7 @@ 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; }