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 X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 235A0C7619B for ; Mon, 17 Feb 2020 07:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0C3B206D5 for ; Mon, 17 Feb 2020 07:37:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=dlink.ru header.i=@dlink.ru header.b="Qu7oPA1X" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726691AbgBQHhF (ORCPT ); Mon, 17 Feb 2020 02:37:05 -0500 Received: from mail.dlink.ru ([178.170.168.18]:59094 "EHLO fd.dlink.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbgBQHhF (ORCPT ); Mon, 17 Feb 2020 02:37:05 -0500 Received: by fd.dlink.ru (Postfix, from userid 5000) id C55C51B20178; Mon, 17 Feb 2020 10:36:59 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru C55C51B20178 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dlink.ru; s=mail; t=1581925019; bh=eMq5r5AI5OZpxp2xPSJgmnoHlWLUKUDdtJ1FhSVqTnU=; h=From:To:Cc:Subject:Date; b=Qu7oPA1XQlVxL8otZibt8yXwEa3ObLpHjX/fQbG6SMpYsy545pSeupm49AWZ4GJnS GsGbpgQCj0GId/Ceo22WPkNJgO2RbCZa2vb2Kd8C9MugiyfqW9FELRm+9ySRRwtBEp bVK/XMxeUh3BMrH+UgmTmzZzg8OaDnU1oR9x55rk= Received: from mail.rzn.dlink.ru (mail.rzn.dlink.ru [178.170.168.13]) by fd.dlink.ru (Postfix) with ESMTP id B9E4A1B20178; Mon, 17 Feb 2020 10:36:53 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru B9E4A1B20178 Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTP id F38A51B21819; Mon, 17 Feb 2020 10:36:52 +0300 (MSK) Received: from localhost.localdomain (unknown [196.196.203.126]) by mail.rzn.dlink.ru (Postfix) with ESMTPA; Mon, 17 Feb 2020 10:36:52 +0300 (MSK) From: Alexander Lobakin To: Jason Gunthorpe Cc: Leon Romanovsky , Doug Ledford , Randy Dunlap , Maxim Mikityanskiy , Alexander Lobakin , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH rdma] IB/mlx5: Optimize u64 division on 32-bit arches Date: Mon, 17 Feb 2020 10:36:29 +0300 Message-Id: <20200217073629.8051-1-alobakin@dlink.ru> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR capabilities") introduced a straight "/" division of the u64 variable "bar_size". This was fixed with commit 685eff513183 ("IB/mlx5: Use div64_u64 for num_var_hw_entries calculation"). However, div64_u64() is redundant here as mlx5_var_table::stride_size is of type u32. Make the actual code way more optimized on 32-bit kernels using div_u64() and fix 80 chars break-through by the way. Fixes: 685eff513183 ("IB/mlx5: Use div64_u64 for num_var_hw_entries calculation") Signed-off-by: Alexander Lobakin --- drivers/infiniband/hw/mlx5/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index e4bcfa81b70a..026391e4ceb4 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -6545,7 +6545,8 @@ static int mlx5_ib_init_var_table(struct mlx5_ib_dev *dev) doorbell_bar_offset); bar_size = (1ULL << log_doorbell_bar_size) * 4096; var_table->stride_size = 1ULL << log_doorbell_stride; - var_table->num_var_hw_entries = div64_u64(bar_size, var_table->stride_size); + var_table->num_var_hw_entries = div_u64(bar_size, + var_table->stride_size); mutex_init(&var_table->bitmap_lock); var_table->bitmap = bitmap_zalloc(var_table->num_var_hw_entries, GFP_KERNEL); -- 2.25.0