From patchwork Mon May 7 13:57:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10384187 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 26AEE6037F for ; Mon, 7 May 2018 13:57:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07E7728963 for ; Mon, 7 May 2018 13:57:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F06B628B1F; Mon, 7 May 2018 13:57:49 +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 37C7628963 for ; Mon, 7 May 2018 13:57:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B61386E0EB; Mon, 7 May 2018 13:57:48 +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 966CC6E0EB for ; Mon, 7 May 2018 13:57:46 +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 11622002-1500050 for multiple; Mon, 07 May 2018 14:57:36 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Mon, 07 May 2018 14:57:36 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 7 May 2018 14:57:27 +0100 Message-Id: <20180507135731.10587-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180507135731.10587-1-chris@chris-wilson.co.uk> References: <20180507135731.10587-1-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH v2 3/7] drm/i915/execlists: Make submission tasklet hardirq safe 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: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Prepare to allow the execlists submission to be run from underneath a hardirq timer context (and not just the current softirq context) as is required for fast preemption resets and context switches. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_lrc.c | 42 ++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index f9f4064dec0e..15c373ea5b7e 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -357,10 +357,13 @@ execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists) { struct intel_engine_cs *engine = container_of(execlists, typeof(*engine), execlists); + unsigned long flags; + + spin_lock_irqsave(&engine->timeline.lock, flags); - spin_lock_irq(&engine->timeline.lock); __unwind_incomplete_requests(engine); - spin_unlock_irq(&engine->timeline.lock); + + spin_unlock_irqrestore(&engine->timeline.lock, flags); } static inline void @@ -554,7 +557,7 @@ static void inject_preempt_context(struct intel_engine_cs *engine) execlists_set_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT); } -static void execlists_dequeue(struct intel_engine_cs *engine) +static bool __execlists_dequeue(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct execlist_port *port = execlists->port; @@ -564,6 +567,8 @@ static void execlists_dequeue(struct intel_engine_cs *engine) struct rb_node *rb; bool submit = false; + lockdep_assert_held(&engine->timeline.lock); + /* Hardware submission is through 2 ports. Conceptually each port * has a (RING_START, RING_HEAD, RING_TAIL) tuple. RING_START is * static for a context, and unique to each, so we only execute @@ -585,7 +590,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine) * and context switches) submission. */ - spin_lock_irq(&engine->timeline.lock); rb = execlists->first; GEM_BUG_ON(rb_first(&execlists->queue) != rb); @@ -600,7 +604,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine) EXECLISTS_ACTIVE_USER)); GEM_BUG_ON(!port_count(&port[0])); if (port_count(&port[0]) > 1) - goto unlock; + return false; /* * If we write to ELSP a second time before the HW has had @@ -610,11 +614,11 @@ static void execlists_dequeue(struct intel_engine_cs *engine) * the HW to indicate that it has had a chance to respond. */ if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_HWACK)) - goto unlock; + return false; if (need_preempt(engine, last, execlists->queue_priority)) { inject_preempt_context(engine); - goto unlock; + return false; } /* @@ -639,7 +643,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine) * priorities of the ports haven't been switch. */ if (port_count(&port[1])) - goto unlock; + return false; /* * WaIdleLiteRestore:bdw,skl @@ -744,13 +748,25 @@ static void execlists_dequeue(struct intel_engine_cs *engine) /* We must always keep the beast fed if we have work piled up */ GEM_BUG_ON(execlists->first && !port_isset(execlists->port)); -unlock: - spin_unlock_irq(&engine->timeline.lock); - - if (submit) { + /* Re-evaluate the executing context setup after each preemptive kick */ + if (last) execlists_user_begin(execlists, execlists->port); + + return submit; +} + +static void execlists_dequeue(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + unsigned long flags; + bool submit; + + spin_lock_irqsave(&engine->timeline.lock, flags); + submit = __execlists_dequeue(engine); + spin_unlock_irqrestore(&engine->timeline.lock, flags); + + if (submit) execlists_submit_ports(engine); - } GEM_BUG_ON(port_isset(execlists->port) && !execlists_is_active(execlists, EXECLISTS_ACTIVE_USER));