From patchwork Wed Mar 28 21:18:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10314149 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 00E18600F6 for ; Wed, 28 Mar 2018 21:19:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E59C829188 for ; Wed, 28 Mar 2018 21:19:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DA78E2990A; Wed, 28 Mar 2018 21:19:29 +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=-4.2 required=2.0 tests=BAYES_00, 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 7896C29188 for ; Wed, 28 Mar 2018 21:19:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7AC296E261; Wed, 28 Mar 2018 21:19:25 +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 071D98982D for ; Wed, 28 Mar 2018 21:19:22 +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 11193793-1500050 for multiple; Wed, 28 Mar 2018 22:19:16 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 28 Mar 2018 22:19:16 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 28 Mar 2018 22:18:50 +0100 Message-Id: <20180328211857.32457-9-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180328211857.32457-1-chris@chris-wilson.co.uk> References: <20180328211857.32457-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 08/15] drm/i915: Combine tasklet_kill and tasklet_disable 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 Ideally, we want to atomically flush and disable the tasklet before resetting the GPU. At present, we rely on being the only part to touch our tasklet and serialisation of the reset process to ensure that we can suspend the tasklet from the mix of reset/wedge pathways. In this patch, we move the tasklet abuse into its own function and tweak it such that we only do a synchronous operation the first time it is disabled around the reset. This allows us to avoid the sync inside a softirq context in subsequent patches. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Michał Winiarski CC: Michel Thierry Cc: Jeff McGee --- drivers/gpu/drm/i915/intel_lrc.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 7aecf8b37139..be1737d42d43 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1722,6 +1722,16 @@ static int gen9_init_render_ring(struct intel_engine_cs *engine) return init_workarounds_ring(engine); } +static void tasklet_kill_and_disable(struct tasklet_struct *t) +{ + if (!atomic_read(&t->count)) + tasklet_kill(t); + + if (atomic_inc_return(&t->count) == 1) + tasklet_unlock_wait(t); + smp_mb(); +} + static struct i915_request * execlists_reset_prepare(struct intel_engine_cs *engine) { @@ -1746,9 +1756,7 @@ execlists_reset_prepare(struct intel_engine_cs *engine) * common case of recursively being called from set-wedged from inside * i915_reset. */ - if (!atomic_read(&execlists->tasklet.count)) - tasklet_kill(&execlists->tasklet); - tasklet_disable(&execlists->tasklet); + tasklet_kill_and_disable(&execlists->tasklet); /* * We want to flush the pending context switches, having disabled