From patchwork Wed Jun 27 11:38:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10491225 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 AF437602B3 for ; Wed, 27 Jun 2018 11:38:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0AE128C87 for ; Wed, 27 Jun 2018 11:38:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9593328C95; Wed, 27 Jun 2018 11:38:59 +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 3BF0928C88 for ; Wed, 27 Jun 2018 11:38:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BE9746E8BB; Wed, 27 Jun 2018 11:38:57 +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 8644C6E8BB for ; Wed, 27 Jun 2018 11:38:56 +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 12174372-1500050 for multiple; Wed, 27 Jun 2018 12:38:45 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 27 Jun 2018 12:38:43 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 27 Jun 2018 12:38:38 +0100 Message-Id: <20180627113843.7257-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.18.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 1/6] drm/i915/execlists: Pull submit after dequeue under timeline lock 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 In the next patch, we will begin processing the CSB from inside the submission path (underneath an irqsoff section, and even from inside interrupt handlers). This means that updating the execlists->port[] will no longer be serialised by the tasklet but needs to be locked by the engine->timeline.lock instead. Pull dequeue and submit under the same lock for protection. (An alternate future plan is to keep the in/out arrays separate for concurrent processing and reduced lock coverage.) Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_lrc.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 2b21a6596360..009db92b67d7 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -567,7 +567,7 @@ static void complete_preempt_context(struct intel_engine_execlists *execlists) execlists_clear_active(execlists, EXECLISTS_ACTIVE_PREEMPT); } -static bool __execlists_dequeue(struct intel_engine_cs *engine) +static void __execlists_dequeue(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct execlist_port *port = execlists->port; @@ -622,11 +622,11 @@ static bool __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)) - return false; + return; if (need_preempt(engine, last, execlists->queue_priority)) { inject_preempt_context(engine); - return false; + return; } /* @@ -651,7 +651,7 @@ static bool __execlists_dequeue(struct intel_engine_cs *engine) * priorities of the ports haven't been switch. */ if (port_count(&port[1])) - return false; + return; /* * WaIdleLiteRestore:bdw,skl @@ -751,8 +751,10 @@ static bool __execlists_dequeue(struct intel_engine_cs *engine) port != execlists->port ? rq_prio(last) : INT_MIN; execlists->first = rb; - if (submit) + if (submit) { port_assign(port, last); + execlists_submit_ports(engine); + } /* We must always keep the beast fed if we have work piled up */ GEM_BUG_ON(execlists->first && !port_isset(execlists->port)); @@ -761,24 +763,19 @@ static bool __execlists_dequeue(struct intel_engine_cs *engine) if (last) execlists_user_begin(execlists, execlists->port); - return submit; + /* If the engine is now idle, so should be the flag; and vice versa. */ + GEM_BUG_ON(execlists_is_active(&engine->execlists, + EXECLISTS_ACTIVE_USER) == + !port_isset(engine->execlists.port)); } 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); + __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)); } void @@ -1161,11 +1158,6 @@ static void execlists_submission_tasklet(unsigned long data) if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT)) execlists_dequeue(engine); - - /* If the engine is now idle, so should be the flag; and vice versa. */ - GEM_BUG_ON(execlists_is_active(&engine->execlists, - EXECLISTS_ACTIVE_USER) == - !port_isset(engine->execlists.port)); } static void queue_request(struct intel_engine_cs *engine,