From patchwork Fri Oct 21 06:46:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13014316 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 0AF98C4332F for ; Fri, 21 Oct 2022 06:48:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230096AbiJUGr4 (ORCPT ); Fri, 21 Oct 2022 02:47:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230081AbiJUGrw (ORCPT ); Fri, 21 Oct 2022 02:47:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2283242C9A; Thu, 20 Oct 2022 23:47:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 75E2D601D2; Fri, 21 Oct 2022 06:47:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3732C433B5; Fri, 21 Oct 2022 06:47:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666334867; bh=eTZxC1jB3/0V0Rfdced1bkYKZ1MT7sUu1FOTOt8PolQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rRPlIRnOPhzMeB6r2V5WpRI38L/sUcuGWNXwbuxeqVmZJUJJGEDr8OwqSSrW9fkLG EHPqh79YREql28uu+U4qACvVhcUmShrYVch1nLLjMZnrGJvlwyToAOp2ChtnrfYy0T QjXqbD4rIHjAWC8V7pVCiELsG/RQC8ayfStX1k2tUuEy3VK86c3Ej1YtRESwyXXE1m 7pZU9zLSMqGtQk7fD1xQndAa9SiMkjZm7+0l8U8bMeofhe87iMzg4GkwzQ59XK5ANB YcWlJegft5yoUFUt2CoASsvH4DBybXMwtTkOH7A1eK6vGJyL+RLoVaqmqmW7+oFHeK AHx/XtL8g4Tjw== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1olloc-0001fW-GM; Fri, 21 Oct 2022 08:47:34 +0200 From: Johan Hovold To: Stanimir Varbanov , Lorenzo Pieralisi Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Bjorn Helgaas , Rob Herring , Krzysztof Kozlowski , =?utf-8?q?Krzyszto?= =?utf-8?q?f_Wilczy=C5=84ski?= , Manivannan Sadhasivam , Krishna chaitanya chundru , quic_vbadigan@quicinc.com, Brian Masney , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH v2 2/2] PCI: qcom: Add basic interconnect support Date: Fri, 21 Oct 2022 08:46:16 +0200 Message-Id: <20221021064616.6380-3-johan+linaro@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021064616.6380-1-johan+linaro@kernel.org> References: <20221021064616.6380-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Qualcomm platforms like SC8280XP and SA8540P, interconnect bandwidth must be requested before enabling interconnect clocks. Add basic support for managing an optional "pcie-mem" interconnect path by setting a low constraint before enabling clocks and updating it after the link is up. Note that it is not possible for a controller driver to set anything but a maximum peak bandwidth as expected average bandwidth will vary with use case and actual use (and power policy?). This very much remains an unresolved problem with the interconnect framework. Also note that no constraint is set for the SC8280XP/SA8540P "cpu-pcie" path for now as it is not clear what an appropriate constraint would be (and the system does not crash when left unspecified). Fixes: 70574511f3fc ("PCI: qcom: Add support for SC8280XP") Reviewed-by: Brian Masney Signed-off-by: Johan Hovold Acked-by: Georgi Djakov --- drivers/pci/controller/dwc/pcie-qcom.c | 76 ++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 7db94a22238d..0c13f976626f 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -224,6 +225,7 @@ struct qcom_pcie { union qcom_pcie_resources res; struct phy *phy; struct gpio_desc *reset; + struct icc_path *icc_mem; const struct qcom_pcie_cfg *cfg; }; @@ -1644,6 +1646,74 @@ static const struct dw_pcie_ops dw_pcie_ops = { .start_link = qcom_pcie_start_link, }; +static int qcom_pcie_icc_init(struct qcom_pcie *pcie) +{ + struct dw_pcie *pci = pcie->pci; + int ret; + + pcie->icc_mem = devm_of_icc_get(pci->dev, "pcie-mem"); + if (IS_ERR(pcie->icc_mem)) { + ret = PTR_ERR(pcie->icc_mem); + return ret; + } + + /* + * Some Qualcomm platforms require interconnect bandwidth constraints + * to be set before enabling interconnect clocks. + * + * Set an initial peak bandwidth corresponding to single-lane Gen 1 + * for the pcie-mem path. + */ + ret = icc_set_bw(pcie->icc_mem, 0, MBps_to_icc(250)); + if (ret) { + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", + ret); + return ret; + } + + return 0; +} + +static void qcom_pcie_icc_update(struct qcom_pcie *pcie) +{ + struct dw_pcie *pci = pcie->pci; + u32 offset, status, bw; + int speed, width; + int ret; + + if (!pcie->icc_mem) + return; + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA); + + /* Only update constraints if link is up. */ + if (!(status & PCI_EXP_LNKSTA_DLLLA)) + return; + + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status); + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status); + + switch (speed) { + case 1: + bw = MBps_to_icc(250); + break; + case 2: + bw = MBps_to_icc(500); + break; + default: + case 3: + bw = MBps_to_icc(985); + break; + } + + ret = icc_set_bw(pcie->icc_mem, 0, width * bw); + if (ret) { + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", + ret); + } +} + static int qcom_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1704,6 +1774,10 @@ static int qcom_pcie_probe(struct platform_device *pdev) goto err_pm_runtime_put; } + ret = qcom_pcie_icc_init(pcie); + if (ret) + goto err_pm_runtime_put; + ret = pcie->cfg->ops->get_resources(pcie); if (ret) goto err_pm_runtime_put; @@ -1722,6 +1796,8 @@ static int qcom_pcie_probe(struct platform_device *pdev) goto err_phy_exit; } + qcom_pcie_icc_update(pcie); + return 0; err_phy_exit: