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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 378BFCCA47F for ; Fri, 10 Jun 2022 08:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347370AbiFJI3e (ORCPT ); Fri, 10 Jun 2022 04:29:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347644AbiFJI1q (ORCPT ); Fri, 10 Jun 2022 04:27:46 -0400 Received: from mail.baikalelectronics.com (mail.baikalelectronics.com [87.245.175.230]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3CE202A3; Fri, 10 Jun 2022 01:25:56 -0700 (PDT) Received: from mail (mail.baikal.int [192.168.51.25]) by mail.baikalelectronics.com (Postfix) with ESMTP id 6F41EBD1; Fri, 10 Jun 2022 11:26:35 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.com 6F41EBD1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1654849595; bh=JD1oPiZAWSH2srGkuCaPH6/N1KlUYxj06tr7sZo7uHc=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=ZFCvQhLR9bcyCG62CYwX4FaoB8JSBFaP9g7/dHLhYgzylWYVjUAKA1oZAt3xczJGn jzhPL0xmcrepKsFcP3QoL9c7E1Bnp0FircPTgCix8kfTqWYJchE/PsTmhqWClSPPJz 3NQvVr0VATBppHTRWa93ZmsR1IRbML5n+FtVfLMI= Received: from localhost (192.168.53.207) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 10 Jun 2022 11:25:43 +0300 From: Serge Semin To: Rob Herring , Bjorn Helgaas , Lorenzo Pieralisi , Jingoo Han , Gustavo Pimentel , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Frank Li , Manivannan Sadhasivam , , Subject: [PATCH v4 09/18] PCI: dwc: Discard IP-core version checking on unrolled iATU detection Date: Fri, 10 Jun 2022 11:25:25 +0300 Message-ID: <20220610082535.12802-10-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220610082535.12802-1-Sergey.Semin@baikalelectronics.ru> References: <20220610082535.12802-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org It's pretty much pointless. Even though unrolled version of the internal ATU has been indeed available since DWC PCIe v4.80a IP-core, there is no guarantee it was enabled during the IP-core configuration (Synopsys suggests to contact the Solvnet support for guidance of how to do that for the newer IP-cores). So the only reliable way to find out the unrolled iATU feature availability is indeed to check the iATU viewport register content. In accordance with the reference manual [1] if the register doesn't exist (unrolled iATU is enabled) it's content is fixed with 0xff-s, otherwise it will contain some zeros. So we can freely drop the IP-core version checking in this matter then and use the dw_pcie_iatu_unroll_enabled() method only to detect whether iATU/eDMA space is unrolled. [1] DesignWare Cores, PCI Express Controller, Register Desciptions, v.4.90a, December 2016, p.855 Signed-off-by: Serge Semin Reviewed-by: Manivannan Sadhasivam Tested-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pcie-designware.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index ac966ed28c5b..e5c30695f664 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -600,15 +600,15 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) } -static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci) +static bool dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci) { u32 val; val = dw_pcie_readl_dbi(pci, PCIE_ATU_VIEWPORT); if (val == 0xffffffff) - return 1; + return true; - return 0; + return false; } static void dw_pcie_iatu_detect_regions_unroll(struct dw_pcie *pci) @@ -680,9 +680,8 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci) struct device *dev = pci->dev; struct platform_device *pdev = to_platform_device(dev); - if (pci->version >= 0x480A || (!pci->version && - dw_pcie_iatu_unroll_enabled(pci))) { - pci->iatu_unroll_enabled = true; + pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci); + if (pci->iatu_unroll_enabled) { if (!pci->atu_base) { struct resource *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu"); -- 2.35.1