From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 225BCEB64DA for ; Mon, 10 Jul 2023 09:42:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D032310E253; Mon, 10 Jul 2023 09:42:05 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id F1FDC10E266 for ; Mon, 10 Jul 2023 09:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1688982121; x=1720518121; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=bbzCFGhX/TD9kKvcXGLSHQREE/HwdS7Yo4DkVT3b3ok=; b=hYT+Of8MoyocIPC5q7dM1wih/BvB1tn3rPjj0fa8QnOsqtuBRYmn6XLx sZOBU+Y64khkCBQ0PKMOT3BrdDRPS+vFn7TKfi7gCQTOGzpV/mlmZNgnI ElcuGV7RIXj4PLJwObiB8zm0RjIV6iXALJlfu9B1wkxHzNT8TFTu1Og8c pLC8FFGkjZShk7sgZZo7ei9A3L8AQSFE4IrcZ3yuGgOiv2Hvte0SyjJzb FXioNkV2oNzNvlxZ1LPvCPgfBidCLWJyyjrtTU15NX4FrzyFWksnMn21F YyMbAS6yH9mZfd9WV9CV7KxuBXUA2WqGIYEoivO4wrgU/4Y9tNPH0j75d Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10766"; a="395081099" X-IronPort-AV: E=Sophos;i="6.01,194,1684825200"; d="scan'208";a="395081099" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2023 02:42:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10766"; a="755940601" X-IronPort-AV: E=Sophos;i="6.01,194,1684825200"; d="scan'208";a="755940601" Received: from congsip-mobl2.ger.corp.intel.com (HELO mwauld-desk1.intel.com) ([10.252.28.16]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2023 02:42:00 -0700 From: Matthew Auld To: intel-xe@lists.freedesktop.org Date: Mon, 10 Jul 2023 10:40:39 +0100 Message-ID: <20230710094037.28179-14-matthew.auld@intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230710094037.28179-13-matthew.auld@intel.com> References: <20230710094037.28179-13-matthew.auld@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-xe] [PATCH v6 01/11] drm/xe/tlb: drop unnecessary smp_wmb() X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" wake_up_all() and wait_event_timeout() already have the correct barriers as per https://www.kernel.org/doc/Documentation/memory-barriers.txt. This should ensure that the seqno_recv write can't be re-ordered wrt to the actual wake_up_all() i.e we get woken up but there is no write. The reader side with wait_event_timeout() also has the correct barriers. With that drop the hand rolled smp_wmb(), which is anyway missing some kind of matching barrier on the reader side. Signed-off-by: Matthew Auld Cc: Matthew Brost Cc: José Roberto de Souza Reviewed-by: Matthew Brost --- drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c index 2fcb477604e2..08432f472e2d 100644 --- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c +++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c @@ -333,8 +333,11 @@ int xe_guc_tlb_invalidation_done_handler(struct xe_guc *guc, u32 *msg, u32 len) expected_seqno, msg[0]); } + /* + * wake_up_all() and wait_event_timeout() already have the correct + * barriers. + */ gt->tlb_invalidation.seqno_recv = msg[0]; - smp_wmb(); wake_up_all(&guc->ct.wq); fence = list_first_entry_or_null(>->tlb_invalidation.pending_fences, -- 2.41.0