From patchwork Fri Apr 27 12:00:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gustavo Pimentel X-Patchwork-Id: 905675 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=synopsys.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=synopsys.com header.i=@synopsys.com header.b="Tn/azhfp"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40XXbl70Htz9s02 for ; Fri, 27 Apr 2018 22:01:55 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758097AbeD0MBl (ORCPT ); Fri, 27 Apr 2018 08:01:41 -0400 Received: from smtprelay6.synopsys.com ([198.182.37.59]:36058 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757661AbeD0MAO (ORCPT ); Fri, 27 Apr 2018 08:00:14 -0400 Received: from mailhost.synopsys.com (mailhost3.synopsys.com [10.12.238.238]) by smtprelay.synopsys.com (Postfix) with ESMTP id 4CDEE1E130E; Fri, 27 Apr 2018 14:00:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1524830412; bh=9QQTlkkuXti4u/ap/0eUyb6YinmoaDwPG93yP1MN1pw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=Tn/azhfpbz+YMcpjLaBtjAo5jQKC//d801gdBNgEYrN3VOgpr0pYP5PD/RZXYvQQD NfYtvadQ0JBjl17cOID5b3JYoZweZDrpcGgE0gnr26TIFLdPcy8NBGV/BKxS3WxajO KPCgkF72fPbHe1VNaeHqgsB289QLfc5/6YJu7n3W93+LzlqyLJ9V4HaqeQxsjlcGQN +SshiHR+6MHTdw4XF6c0wG/YAJPcS9QpwGR388P19KQpgKUbzIwAw+29LJe0jnDqxk z1AqLmjeBzsFqWN7py17MdYvv7rWMPTuN5hfF7W/4V5Ppmia9D3tj4n0ZGXbQXRFLA A7yXdQPTJFgNw== Received: from pt02.synopsys.com (pt02.internal.synopsys.com [10.107.23.240]) by mailhost.synopsys.com (Postfix) with ESMTP id 561413D36; Fri, 27 Apr 2018 05:00:11 -0700 (PDT) Received: from UbuntuMate-64Bits.internal.synopsys.com (gustavo-e7480.internal.synopsys.com [10.107.25.102]) by pt02.synopsys.com (Postfix) with ESMTP id EA53E3E579; Fri, 27 Apr 2018 13:00:08 +0100 (WEST) From: Gustavo Pimentel To: bhelgaas@google.com, lorenzo.pieralisi@arm.com, Joao.Pinto@synopsys.com, jingoohan1@gmail.com, kishon@ti.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, gustavo.pimentel@synopsys.com Subject: [PATCH v8 8/9] PCI: dwc: Small computation improvement Date: Fri, 27 Apr 2018 13:00:03 +0100 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Replace a division by 2 operation for a right shift rotation of 1 bit. Probably any recent and decent compiler does this kind of substitution in order to improve code performance. Nevertheless it's a coding good practice whenever there is a division / multiplication by multiple of 2 to replace it by the equivalent operation in this case, the shift rotation. Signed-off-by: Gustavo Pimentel Acked-by: Jingoo Han Acked-by: Joao Pinto --- Change v1->v2: - Nothing changed, just to follow the patch set version. Change v2->v3: - Nothing changed, just to follow the patch set version. Changes v3->v4: - Added a small explication to the log description. Changes v4->v5: - Nothing changed, just to follow the patch set version. Changes v5->v6: - Nothing changed, just to follow the patch set version. Changes v6->v7: - Nothing changed, just to follow the patch set version. Changes v7->v8: - Patch description rework for an imperative verbal mode. drivers/pci/dwc/pcie-designware-host.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c index 5a23f78..fc55fde 100644 --- a/drivers/pci/dwc/pcie-designware-host.c +++ b/drivers/pci/dwc/pcie-designware-host.c @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp) cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config"); if (cfg_res) { - pp->cfg0_size = resource_size(cfg_res) / 2; - pp->cfg1_size = resource_size(cfg_res) / 2; + pp->cfg0_size = resource_size(cfg_res) >> 1; + pp->cfg1_size = resource_size(cfg_res) >> 1; pp->cfg0_base = cfg_res->start; pp->cfg1_base = cfg_res->start + pp->cfg0_size; } else if (!pp->va_cfg0_base) { @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp) break; case 0: pp->cfg = win->res; - pp->cfg0_size = resource_size(pp->cfg) / 2; - pp->cfg1_size = resource_size(pp->cfg) / 2; + pp->cfg0_size = resource_size(pp->cfg) >> 1; + pp->cfg1_size = resource_size(pp->cfg) >> 1; pp->cfg0_base = pp->cfg->start; pp->cfg1_base = pp->cfg->start + pp->cfg0_size; break;