From patchwork Fri Mar 30 10:39:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10317593 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 B92C6602D6 for ; Fri, 30 Mar 2018 10:40:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A857B286C8 for ; Fri, 30 Mar 2018 10:40:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 99376286E0; Fri, 30 Mar 2018 10:40:05 +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 259D5286C8 for ; Fri, 30 Mar 2018 10:40:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 369476E862; Fri, 30 Mar 2018 10:40:04 +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 4E8856E3FD for ; Fri, 30 Mar 2018 10:39:44 +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 11213814-1500050 for multiple; Fri, 30 Mar 2018 11:39:40 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 30 Mar 2018 11:39:38 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 30 Mar 2018 11:39:07 +0100 Message-Id: <20180330103915.23018-10-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180330103915.23018-1-chris@chris-wilson.co.uk> References: <20180330103915.23018-1-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 09/17] 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 cba1ecda126a..8fe9e62c5d18 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1745,6 +1745,16 @@ 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) { @@ -1769,9 +1779,7 @@ 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