From patchwork Fri Mar 30 15:55:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10318067 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 563EA6055B for ; Fri, 30 Mar 2018 15:56:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 47AEF2A523 for ; Fri, 30 Mar 2018 15:56:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BC542A532; Fri, 30 Mar 2018 15:56:34 +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 BDA182A523 for ; Fri, 30 Mar 2018 15:56:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0CE776E8FF; Fri, 30 Mar 2018 15:56:33 +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 43BF06E90B for ; Fri, 30 Mar 2018 15:56:14 +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 11216736-1500050 for multiple; Fri, 30 Mar 2018 16:56:05 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 30 Mar 2018 16:56:04 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 30 Mar 2018 16:55:31 +0100 Message-Id: <20180330155539.9554-11-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180330155539.9554-1-chris@chris-wilson.co.uk> References: <20180330155539.9554-1-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 10/18] 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