From patchwork Wed Jun 25 14:10:16 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 32484 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-ob0-f199.google.com (mail-ob0-f199.google.com [209.85.214.199]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id 021F120C88 for ; Wed, 25 Jun 2014 14:10:43 +0000 (UTC) Received: by mail-ob0-f199.google.com with SMTP id va2sf10627087obc.10 for ; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:in-reply-to:references:sender:precedence:list-id :x-original-sender:x-original-authentication-results:mailing-list :list-post:list-help:list-archive:list-unsubscribe:content-type :content-transfer-encoding; bh=wIG6288ogPcbGMLcacZF421P4GmyM9ggTYr2Bd78th4=; b=Ei2uY5+w9oaQyLJ/PjGw4dDcqgKhOnyu0QD4cC7jTt5Rb+TlcFIs8z70FHInyZwTDU qZlN9qVlGZGSS4N7zMvm3afHGX3ETeqzKiYwM5YWJDQB/1cIQPDkamYybphDMn68YHma wgkyPQFckcXAEhXyCLZq5EWSUfsg6ZFJM4rrw7z71EcU8hgLogYAynylI3yoazs8c81H vTtGFxUwsqNVB+yIO9yMQcOMt03+V3hI+GUHTLl645e+XtNCWXLx3DM82bMNGRckX4HG 40BkhmJXBMpS8nyZLznpqoYCqeSKi0WPQSSd4P0N1algtx49CRTMW1+5EKjSC4e4U6OX UTlQ== X-Gm-Message-State: ALoCoQkbPII5ey7TZXqiTa6WbZOOzGHfbLZkQTVytIIV4tWjygZde8PYPxxgcpX8tnWYwMFi5g3D X-Received: by 10.182.68.16 with SMTP id r16mr4301662obt.26.1403705443640; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.103.118 with SMTP id x109ls2691810qge.74.gmail; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) X-Received: by 10.220.114.140 with SMTP id e12mr7089758vcq.37.1403705443547; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) Received: from mail-vc0-f169.google.com (mail-vc0-f169.google.com [209.85.220.169]) by mx.google.com with ESMTPS id g10si2326827vdt.41.2014.06.25.07.10.43 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 25 Jun 2014 07:10:43 -0700 (PDT) Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.169 as permitted sender) client-ip=209.85.220.169; Received: by mail-vc0-f169.google.com with SMTP id la4so1958145vcb.14 for ; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) X-Received: by 10.221.26.10 with SMTP id rk10mr7265110vcb.0.1403705443447; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patch@linaro.org Received: by 10.221.37.5 with SMTP id tc5csp292795vcb; Wed, 25 Jun 2014 07:10:43 -0700 (PDT) X-Received: by 10.68.135.67 with SMTP id pq3mr11764103pbb.165.1403705442600; Wed, 25 Jun 2014 07:10:42 -0700 (PDT) Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id co3si5320147pad.238.2014.06.25.07.10.42; Wed, 25 Jun 2014 07:10:42 -0700 (PDT) Received-SPF: none (google.com: linux-pm-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757135AbaFYOKk (ORCPT + 13 others); Wed, 25 Jun 2014 10:10:40 -0400 Received: from service87.mimecast.com ([91.220.42.44]:48391 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757251AbaFYOKb (ORCPT ); Wed, 25 Jun 2014 10:10:31 -0400 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 25 Jun 2014 15:10:29 +0100 Received: from red-moon.cambridge.arm.com ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 25 Jun 2014 15:10:18 +0100 From: Lorenzo Pieralisi To: linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org Cc: Lorenzo Pieralisi , Mark Rutland , Sudeep Holla , Catalin Marinas , Charles Garcia Tobin , Nicolas Pitre , Rob Herring , Grant Likely , Peter De Schrijver , Santosh Shilimkar , Daniel Lezcano , Amit Kucheria , Vincent Guittot , Antti Miettinen , Stephen Boyd , Kevin Hilman , Sebastian Capella , Tomasz Figa , Mark Brown , Paul Walmsley , Chander Kashyap Subject: [PATCH v5 3/8] drivers: cpuidle: implement DT based idle states infrastructure Date: Wed, 25 Jun 2014 15:10:16 +0100 Message-Id: <1403705421-17597-4-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403705421-17597-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1403705421-17597-1-git-send-email-lorenzo.pieralisi@arm.com> X-OriginalArrivalTime: 25 Jun 2014 14:10:18.0609 (UTC) FILETIME=[31B2EE10:01CF907F] X-MC-Unique: 114062515102911301 Sender: linux-pm-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: lorenzo.pieralisi@arm.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.169 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , On most common ARM systems, the low-power states a CPU can be put into are not discoverable in HW and require device tree bindings to describe power down suspend operations and idle states parameters. In order to enable DT based idle states and configure idle drivers, this patch implements the bulk infrastructure required to parse the device tree idle states bindings and initialize the corresponding CPUidle driver states data. Code that initializes idle states checks the CPU idle driver cpumask so that multiple CPU idle drivers can be initialized through it in the kernel. The CPU idle driver cpumask defines which idle states should be considered valid for the driver, ie idle states that are valid on a set of cpus the idle driver manages. Signed-off-by: Lorenzo Pieralisi --- drivers/cpuidle/Kconfig | 8 ++ drivers/cpuidle/Makefile | 1 + drivers/cpuidle/dt_idle_states.c | 283 +++++++++++++++++++++++++++++++++++++++ drivers/cpuidle/dt_idle_states.h | 8 ++ 4 files changed, 300 insertions(+) create mode 100644 drivers/cpuidle/dt_idle_states.c create mode 100644 drivers/cpuidle/dt_idle_states.h diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index 1b96fb9..414e7a96 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -30,6 +30,14 @@ config CPU_IDLE_GOV_MENU bool "Menu governor (for tickless system)" default y +config DT_IDLE_STATES + bool "Idle states DT support" + depends on ARM || ARM64 + help + Allows the CPU idle framework to initialize CPU idle drivers + state data by using DT provided nodes compliant with idle states + device tree bindings. + menu "ARM CPU Idle Drivers" depends on ARM source "drivers/cpuidle/Kconfig.arm" diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index d8bb1ff..b27a062 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -4,6 +4,7 @@ obj-y += cpuidle.o driver.o governor.o sysfs.o governors/ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o +obj-$(CONFIG_DT_IDLE_STATES) += dt_idle_states.o ################################################################################## # ARM SoC drivers diff --git a/drivers/cpuidle/dt_idle_states.c b/drivers/cpuidle/dt_idle_states.c new file mode 100644 index 0000000..5c16001c --- /dev/null +++ b/drivers/cpuidle/dt_idle_states.c @@ -0,0 +1,283 @@ +/* + * DT idle states parsing code. + * + * Copyright (C) 2014 ARM Ltd. + * Author: Lorenzo Pieralisi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) "DT idle-states: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "dt_idle_states.h" + +struct state_elem { + struct list_head list; + struct device_node *node; + u32 val; +}; + +static struct list_head head __initdata = LIST_HEAD_INIT(head); + +static bool __init state_cpu_valid(struct device_node *state_node, + struct device_node *cpu_node) +{ + int i = 0; + struct device_node *cpu_state; + + while ((cpu_state = of_parse_phandle(cpu_node, + "cpu-idle-states", i++))) { + if (cpu_state && state_node == cpu_state) { + of_node_put(cpu_state); + return true; + } + of_node_put(cpu_state); + } + return false; +} + +static bool __init state_cpus_valid(const cpumask_t *cpus, + struct device_node *state_node) +{ + int cpu; + struct device_node *cpu_node; + + /* + * Check if state is valid on driver cpumask cpus + */ + for_each_cpu(cpu, cpus) { + cpu_node = of_get_cpu_node(cpu, NULL); + + if (!cpu_node) { + pr_err("Missing device node for CPU %d\n", cpu); + return false; + } + + if (!state_cpu_valid(state_node, cpu_node)) + return false; + } + + return true; +} + +static int __init state_cmp(void *priv, struct list_head *a, + struct list_head *b) +{ + struct state_elem *ela, *elb; + + ela = container_of(a, struct state_elem, list); + elb = container_of(b, struct state_elem, list); + + return ela->val - elb->val; +} + +static int __init add_state_node(cpumask_t *cpumask, + struct device_node *state_node) +{ + struct state_elem *el; + u32 val; + + pr_debug(" * %s...\n", state_node->full_name); + + if (!state_cpus_valid(cpumask, state_node)) + return -EINVAL; + /* + * Parse just the property required to sort the states. + */ + if (of_property_read_u32(state_node, "power-rank", + &val)) { + pr_debug(" * %s missing power-rank property\n", + state_node->full_name); + return -EINVAL; + } + + el = kmalloc(sizeof(*el), GFP_KERNEL); + if (!el) { + pr_err("%s failed to allocate memory\n", __func__); + return -ENOMEM; + } + + el->node = state_node; + el->val = val; + list_add_tail(&el->list, &head); + + return 0; +} + +static void __init init_state_node(struct cpuidle_driver *drv, + struct device_node *state_node, + int *cnt) +{ + struct cpuidle_state *idle_state; + + pr_debug(" * %s...\n", state_node->full_name); + + idle_state = &drv->states[*cnt]; + + if (of_property_read_u32(state_node, "wakeup-latency-us", + &idle_state->exit_latency)) { + u32 entry_latency, exit_latency; + + if (of_property_read_u32(state_node, "entry-latency-us", + &entry_latency)) { + pr_debug(" * %s missing entry-latency-us property\n", + state_node->full_name); + return; + } + + if (of_property_read_u32(state_node, "exit-latency-us", + &exit_latency)) { + pr_debug(" * %s missing exit-latency-us property\n", + state_node->full_name); + return; + } + /* + * If wakeup-latency-us is missing, default to entry+exit + * latencies as defined in idle states bindings + */ + idle_state->exit_latency = entry_latency + exit_latency; + } + + if (of_property_read_u32(state_node, "min-residency-us", + &idle_state->target_residency)) { + pr_debug(" * %s missing min-residency-us property\n", + state_node->full_name); + return; + } + + idle_state->flags = CPUIDLE_FLAG_TIME_VALID; + if (!of_property_read_bool(state_node, "timer-state-retained")) + idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP; + + strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN); + strncpy(idle_state->desc, state_node->name, CPUIDLE_NAME_LEN); + + (*cnt)++; +} + +static int __init init_idle_states(struct cpuidle_driver *drv, + struct device_node *state_nodes[], + unsigned int start_idx, bool init_nodes) +{ + struct state_elem *el; + struct list_head *curr, *tmp; + unsigned int cnt = start_idx; + + list_for_each_entry(el, &head, list) { + /* + * Check if the init function has to fill the + * state_nodes array on behalf of the CPUidle driver. + */ + if (init_nodes) + state_nodes[cnt] = el->node; + /* + * cnt is updated on return if a state was added. + */ + init_state_node(drv, el->node, &cnt); + + if (cnt == CPUIDLE_STATE_MAX) { + pr_warn("State index reached static CPU idle state limit\n"); + break; + } + } + + drv->state_count = cnt; + + list_for_each_safe(curr, tmp, &head) { + list_del(curr); + kfree(container_of(curr, struct state_elem, list)); + } + + /* + * If no idle states are detected, return an error and let the idle + * driver initialization fail accordingly. + */ + return (cnt > start_idx) ? 0 : -ENODATA; +} + +static void __init add_idle_states(struct cpuidle_driver *drv, + struct device_node *idle_states) +{ + struct device_node *state_node; + + for_each_child_of_node(idle_states, state_node) { + if ((!of_device_is_compatible(state_node, "arm,idle-state"))) { + pr_warn(" * %s: children of /cpus/idle-states must be \"arm,idle-state\" compatible\n", + state_node->full_name); + continue; + } + /* + * If memory allocation fails, better bail out. + * Initialized nodes are freed at initialization + * completion in of_init_idle_driver(). + */ + if ((add_state_node(drv->cpumask, state_node) == -ENOMEM)) + break; + } + /* + * Sort the states list before initializing the CPUidle driver + * states array. + */ + list_sort(NULL, &head, state_cmp); +} + +/** + * dt_init_idle_driver() - Parse the DT idle states and initialize the + * idle driver states array + * + * @drv: Pointer to CPU idle driver to be initialized + * @state_nodes: Array of struct device_nodes to be initialized if + * init_nodes == true. Must be sized CPUIDLE_STATE_MAX + * @start_idx: First idle state index to be initialized + * @init_nodes: Boolean to request device nodes initialization + * + * On success the states array in the cpuidle driver contains + * initialized entries in the states array, starting from index start_idx. + * If init_nodes == true, on success the state_nodes array is initialized + * with idle state DT node pointers, starting from index start_idx, + * in a 1:1 relation with the idle driver states array. + * + * Return: + * 0 on success + * <0 on failure + */ +int __init dt_init_idle_driver(struct cpuidle_driver *drv, + struct device_node *state_nodes[], + unsigned int start_idx, bool init_nodes) +{ + struct device_node *idle_states_node; + int ret; + + if (start_idx >= CPUIDLE_STATE_MAX) { + pr_warn("State index exceeds static CPU idle driver states array size\n"); + return -EINVAL; + } + + if (WARN(init_nodes && !state_nodes, + "Requested nodes stashing in an invalid nodes container\n")) + return -EINVAL; + + idle_states_node = of_find_node_by_path("/cpus/idle-states"); + if (!idle_states_node) + return -ENOENT; + + add_idle_states(drv, idle_states_node); + + ret = init_idle_states(drv, state_nodes, start_idx, init_nodes); + + of_node_put(idle_states_node); + + return ret; +} diff --git a/drivers/cpuidle/dt_idle_states.h b/drivers/cpuidle/dt_idle_states.h new file mode 100644 index 0000000..e74f1e8 --- /dev/null +++ b/drivers/cpuidle/dt_idle_states.h @@ -0,0 +1,8 @@ +#ifndef __DT_IDLE_STATES +#define __DT_IDLE_STATES + +int __init dt_init_idle_driver(struct cpuidle_driver *drv, + struct device_node *state_nodes[], + unsigned int start_idx, + bool init_nodes); +#endif