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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CB31C6783C for ; Fri, 12 Oct 2018 14:33:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECB7920835 for ; Fri, 12 Oct 2018 14:33:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECB7920835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728863AbeJLWGj (ORCPT ); Fri, 12 Oct 2018 18:06:39 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:52048 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728708AbeJLWGi (ORCPT ); Fri, 12 Oct 2018 18:06:38 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 878F4F; Fri, 12 Oct 2018 07:33:55 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 977AC3F5BC; Fri, 12 Oct 2018 07:33:52 -0700 (PDT) Date: Fri, 12 Oct 2018 15:33:50 +0100 From: Sudeep Holla To: "Raju P.L.S.S.S.N" Cc: andy.gross@linaro.org, david.brown@linaro.org, rjw@rjwysocki.net, ulf.hansson@linaro.org, khilman@kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, rnayak@codeaurora.org, bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, sboyd@kernel.org, evgreen@chromium.org, dianders@chromium.org, mka@chromium.org, ilina@codeaurora.org Subject: Re: [PATCH RFC v1 4/8] drivers: qcom: cpu_pd: add cpu power domain support using genpd Message-ID: <20181012143350.GG3401@e107155-lin> References: <1539206455-29342-1-git-send-email-rplsssn@codeaurora.org> <1539206455-29342-5-git-send-email-rplsssn@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1539206455-29342-5-git-send-email-rplsssn@codeaurora.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 11, 2018 at 02:50:51AM +0530, Raju P.L.S.S.S.N wrote: > RPMH based targets require that the sleep and wake state request votes > be sent during system low power mode entry. The votes help reduce the > power consumption when the AP is not using them. The votes sent by the > clients are cached in RPMH controller and needs to be flushed when the > last cpu enters low power mode. So add cpu power domain using Linux > generic power domain infrastructure to perform necessary tasks as part > of domain power down. > > Suggested-by: Lina Iyer > Signed-off-by: Raju P.L.S.S.S.N > --- > drivers/soc/qcom/Kconfig | 9 ++++ > drivers/soc/qcom/Makefile | 1 + > drivers/soc/qcom/cpu_pd.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 114 insertions(+) > create mode 100644 drivers/soc/qcom/cpu_pd.c > > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig > index ba79b60..91e8b3b 100644 > --- a/drivers/soc/qcom/Kconfig > +++ b/drivers/soc/qcom/Kconfig > @@ -95,6 +95,7 @@ config QCOM_RMTFS_MEM > config QCOM_RPMH > bool "Qualcomm RPM-Hardened (RPMH) Communication" > depends on ARCH_QCOM && ARM64 && OF || COMPILE_TEST > + select QCOM_CPU_PD > help > Support for communication with the hardened-RPM blocks in > Qualcomm Technologies Inc (QTI) SoCs. RPMH communication uses an > @@ -102,6 +103,14 @@ config QCOM_RPMH > of hardware components aggregate requests for these resources and > help apply the aggregated state on the resource. > > +config QCOM_CPU_PD > + bool "Qualcomm cpu power domain driver" > + depends on QCOM_RPMH && PM_GENERIC_DOMAINS || COMPILE_TEST > + help > + Support for QCOM platform cpu power management to perform tasks > + necessary while application processor votes for deeper modes so that > + the firmware can enter SoC level low power modes to save power. > + > config QCOM_SMEM > tristate "Qualcomm Shared Memory Manager (SMEM)" > depends on ARCH_QCOM > diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile > index f25b54c..57a1b0e 100644 > --- a/drivers/soc/qcom/Makefile > +++ b/drivers/soc/qcom/Makefile > @@ -12,6 +12,7 @@ obj-$(CONFIG_QCOM_RMTFS_MEM) += rmtfs_mem.o > obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o > qcom_rpmh-y += rpmh-rsc.o > qcom_rpmh-y += rpmh.o > +obj-$(CONFIG_QCOM_CPU_PD) += cpu_pd.o > obj-$(CONFIG_QCOM_SMD_RPM) += smd-rpm.o > obj-$(CONFIG_QCOM_SMEM) += smem.o > obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o > diff --git a/drivers/soc/qcom/cpu_pd.c b/drivers/soc/qcom/cpu_pd.c > new file mode 100644 > index 0000000..565c510 > --- /dev/null > +++ b/drivers/soc/qcom/cpu_pd.c > @@ -0,0 +1,104 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2018, The Linux Foundation. All rights reserved. > + */ > + > +#include > +#include > +#include > + > +#include > + > +static struct device *cpu_pd_dev; > + This doesn't scale if you have 2 instances. > +static int cpu_pd_power_off(struct generic_pm_domain *domain) > +{ > + if (rpmh_ctrlr_idle(cpu_pd_dev)) { How is this expected to compile ? I couldn't find any instance of this. > + /* Flush the sleep/wake sets */ > + rpmh_flush(cpu_pd_dev); So it's just flushing the pending requests on the controller. The function implementation carries a note that it's assumed to be called only from system PM and we may call it in cpu idle path here. Is that fine ? If so, may be the comment needs to be dropped. Also, where exactly this voting for CPU is happening in this path ? > + } else { > + pr_debug("rpmh controller is busy\n"); > + return -EBUSY; > + } > + > + return 0; > +} > + > +static int cpu_pm_domain_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct generic_pm_domain *cpu_pd; > + int ret = -EINVAL, cpu; > + > + if (!np) { > + dev_err(dev, "device tree node not found\n"); > + return -ENODEV; > + } > + > + if (!of_find_property(np, "#power-domain-cells", NULL)) { > + pr_err("power-domain-cells not found\n"); > + return -ENODEV; > + } > + > + cpu_pd_dev = &pdev->dev; > + if (IS_ERR_OR_NULL(cpu_pd_dev)) Isn't this too late to check ? You would have crashed on dev->of_node. So sounds pretty useless > + return PTR_ERR(cpu_pd_dev); > + > + cpu_pd = devm_kzalloc(dev, sizeof(*cpu_pd), GFP_KERNEL); > + if (!cpu_pd) > + return -ENOMEM; > + > + cpu_pd->name = kasprintf(GFP_KERNEL, "%s", np->name); > + if (!cpu_pd->name) > + goto free_cpu_pd; > + cpu_pd->name = kbasename(cpu_pd->name); > + cpu_pd->power_off = cpu_pd_power_off; If some kind of voting is done in off, why is there nothing to take care of that in pd_power_on if it's per EL(linux/hyp/secure). -- Regards, Sudeep