From patchwork Mon Apr 16 14:37:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gustavo Pimentel X-Patchwork-Id: 898661 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=fail (p=none dis=none) header.from=synopsys.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40Prbv0cxPz9s1R for ; Tue, 17 Apr 2018 00:38:51 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752144AbeDPOi0 (ORCPT ); Mon, 16 Apr 2018 10:38:26 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:38334 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbeDPOiK (ORCPT ); Mon, 16 Apr 2018 10:38:10 -0400 Received: from mailhost.synopsys.com (mailhost3.synopsys.com [10.12.238.238]) by smtprelay.synopsys.com (Postfix) with ESMTP id 7CA2624E1F0C; Mon, 16 Apr 2018 07:38:09 -0700 (PDT) Received: from pt02.synopsys.com (pt02.synopsys.com [10.107.23.240]) by mailhost.synopsys.com (Postfix) with ESMTP id 39ED239FC; Mon, 16 Apr 2018 07:38:09 -0700 (PDT) Received: from UbuntuMate-64Bits.internal.synopsys.com (gustavo-e7480.internal.synopsys.com [10.107.19.134]) by pt02.synopsys.com (Postfix) with ESMTP id 359808B84; Mon, 16 Apr 2018 15:38:08 +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 v4 09/10] PCI: dwc: Small computation improvement Date: Mon, 16 Apr 2018 15:37:57 +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 Replaces a simple division by 2 to 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 --- 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. 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;