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 E5898C4321E for ; Tue, 3 May 2022 21:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240888AbiECV1d (ORCPT ); Tue, 3 May 2022 17:27:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242868AbiECV1W (ORCPT ); Tue, 3 May 2022 17:27:22 -0400 Received: from mail.baikalelectronics.ru (mail.baikalelectronics.com [87.245.175.226]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0E2D441638; Tue, 3 May 2022 14:23:33 -0700 (PDT) Received: from mail.baikalelectronics.ru (unknown [192.168.51.25]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 721B916A9; Wed, 4 May 2022 00:24:07 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.ru 721B916A9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1651613047; bh=aZ0FrYvdbbu8Dgya3SIuok2wzI17oaJMGYt84OA6t2M=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=Dq+bMEOBAp03ImhYsN36vwLB7KNT6XscOGIA5ZkvC7yyu2PQ7oBviPa2uxdZtchgD wX4S5CgbPWmJqd86jjWrdstUV4rkeEBEaVVOuvnxfz1CHnVEe9nd196kqVQIoozhv5 gG4fanaoJPSz3UvacvAJQ8qLRTo+nhzgt0Qwy9rE= Received: from localhost (192.168.53.207) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 4 May 2022 00:23:33 +0300 From: Serge Semin To: Jingoo Han , Gustavo Pimentel , Bjorn Helgaas , Lorenzo Pieralisi , Rob Herring , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Frank Li , Manivannan Sadhasivam , , Subject: [PATCH v2 08/13] PCI: dwc: Discard IP-core version checking on unrolled iATU detection Date: Wed, 4 May 2022 00:22:55 +0300 Message-ID: <20220503212300.30105-9-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220503212300.30105-1-Sergey.Semin@baikalelectronics.ru> References: <20220503212300.30105-1-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 --- 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 3bd1cfd12148..e3d2c11e6998 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