From patchwork Wed May 26 06:42:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12280747 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B204EC47088 for ; Wed, 26 May 2021 06:25:33 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7DE2D613C9 for ; Wed, 26 May 2021 06:25:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DE2D613C9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 89EC56EBAA; Wed, 26 May 2021 06:25:05 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 948ED6EB9C; Wed, 26 May 2021 06:24:51 +0000 (UTC) IronPort-SDR: 4BrRIId1KnQC9ihjejMPA/25pbONF8CkaShWVhsb9PsIG0p9bk+Q1cK7dCSw2raWM7Lv3inf6y Z/J+LrMHgauQ== X-IronPort-AV: E=McAfee;i="6200,9189,9995"; a="182033748" X-IronPort-AV: E=Sophos;i="5.82,330,1613462400"; d="scan'208";a="182033748" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2021 23:24:49 -0700 IronPort-SDR: DJ/GwzxRZKDZJ/Op2wsE6PeWodeMJrVxQpmkT/7ONaeC18tLMiH+9dYOesQWQDeokvdQ9nkZr+ 05l5hek5q1Fw== X-IronPort-AV: E=Sophos;i="5.82,330,1613462400"; d="scan'208";a="633376834" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2021 23:24:49 -0700 From: Matthew Brost To: , Date: Tue, 25 May 2021 23:42:34 -0700 Message-Id: <20210526064237.77853-16-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210526064237.77853-1-matthew.brost@intel.com> References: <20210526064237.77853-1-matthew.brost@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 15/18] drm/i915/guc: Ensure H2G buffer updates visible before tail update X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 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" Ensure H2G buffer updates are visible before descriptor tail updates by inserting a barrier between the H2G buffer update and the tail. The barrier is simple wmb() for SMEM and is register write for LMEM. This is needed if more than 1 H2G can be inflight at once. Signed-off-by: Matthew Brost Cc: Michal Wajdeczko Reviewed-by: John Harrison --- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index fb875d257536..42063e1c355d 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -328,6 +328,18 @@ static u32 ct_get_next_fence(struct intel_guc_ct *ct) return ++ct->requests.last_fence; } +static void write_barrier(struct intel_guc_ct *ct) { + struct intel_guc *guc = ct_to_guc(ct); + struct intel_gt *gt = guc_to_gt(guc); + + if (i915_gem_object_is_lmem(guc->ct.vma->obj)) { + GEM_BUG_ON(guc->send_regs.fw_domains); + intel_uncore_write_fw(gt->uncore, GEN11_SOFT_SCRATCH(0), 0); + } else { + wmb(); + } +} + /** * DOC: CTB Host to GuC request * @@ -411,6 +423,12 @@ static int ct_write(struct intel_guc_ct *ct, } GEM_BUG_ON(tail > size); + /* + * make sure H2G buffer update and LRC tail update (if this triggering a + * submission) are visible before updating the descriptor tail + */ + write_barrier(ct); + /* now update desc tail (back in bytes) */ desc->tail = tail * 4; return 0;