Merge tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc (a35c6322) · Commits · 戴 / test

MAINTAINERS

+9 −0

Original line number	Diff line number	Diff line
		@@ -2307,6 +2307,15 @@ F: drivers/cpufreq/arm_big_little.h
		F: drivers/cpufreq/arm_big_little.c
		F: drivers/cpufreq/arm_big_little_dt.c

		CPUIDLE DRIVER - ARM BIG LITTLE
		M: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
		M: Daniel Lezcano <daniel.lezcano@linaro.org>
		L: linux-pm@vger.kernel.org
		L: linux-arm-kernel@lists.infradead.org
		T: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
		S: Maintained
		F: drivers/cpuidle/cpuidle-big_little.c

		CPUIDLE DRIVERS
		M: Rafael J. Wysocki <rjw@sisk.pl>
		M: Daniel Lezcano <daniel.lezcano@linaro.org>

arch/arm/mach-vexpress/tc2_pm.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include <linux/of_address.h>
		#include <linux/spinlock.h>
		#include <linux/errno.h>
		#include <linux/irqchip/arm-gic.h>

		#include <asm/mcpm.h>
		#include <asm/proc-fns.h>
		@@ -230,6 +231,7 @@ static void tc2_pm_suspend(u64 residency)
		cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
		cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
		ve_spc_set_resume_addr(cluster, cpu, virt_to_phys(mcpm_entry_point));
		gic_cpu_if_down();
		tc2_pm_down(residency);
		}

drivers/cpuidle/Kconfig.arm

+10 −0

Original line number	Diff line number	Diff line
		@@ -27,3 +27,13 @@ config ARM_U8500_CPUIDLE
		help
		Select this to enable cpuidle for ST-E u8500 processors

		config CPU_IDLE_BIG_LITTLE
		bool "Support for ARM big.LITTLE processors"
		depends on ARCH_VEXPRESS_TC2_PM
		select ARM_CPU_SUSPEND
		select CPU_IDLE_MULTIPLE_DRIVERS
		help
		Select this option to enable CPU idle driver for big.LITTLE based
		ARM systems. Driver manages CPUs coordination through MCPM and
		define different C-states for little and big cores through the
		multiple CPU idle drivers infrastructure.

drivers/cpuidle/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -11,3 +11,4 @@ obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE) += cpuidle-calxeda.o
		obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE) += cpuidle-kirkwood.o
		obj-$(CONFIG_ARM_ZYNQ_CPUIDLE) += cpuidle-zynq.o
		obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o
		obj-$(CONFIG_CPU_IDLE_BIG_LITTLE) += cpuidle-big_little.o

drivers/cpuidle/cpuidle-big_little.c

0 → 100644

+209 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2013 ARM/Linaro
		*
		* Authors: Daniel Lezcano <daniel.lezcano@linaro.org>
		* Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
		* Nicolas Pitre <nicolas.pitre@linaro.org>
		*
		* 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.
		*
		* Maintainer: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
		* Maintainer: Daniel Lezcano <daniel.lezcano@linaro.org>
		*/
		#include <linux/cpuidle.h>
		#include <linux/cpu_pm.h>
		#include <linux/slab.h>
		#include <linux/of.h>

		#include <asm/cpu.h>
		#include <asm/cputype.h>
		#include <asm/cpuidle.h>
		#include <asm/mcpm.h>
		#include <asm/smp_plat.h>
		#include <asm/suspend.h>

		static int bl_enter_powerdown(struct cpuidle_device *dev,
		struct cpuidle_driver *drv, int idx);

		/*
		* NB: Owing to current menu governor behaviour big and LITTLE
		* index 1 states have to define exit_latency and target_residency for
		* cluster state since, when all CPUs in a cluster hit it, the cluster
		* can be shutdown. This means that when a single CPU enters this state
		* the exit_latency and target_residency values are somewhat overkill.
		* There is no notion of cluster states in the menu governor, so CPUs
		* have to define CPU states where possibly the cluster will be shutdown
		* depending on the state of other CPUs. idle states entry and exit happen
		* at random times; however the cluster state provides target_residency
		* values as if all CPUs in a cluster enter the state at once; this is
		* somewhat optimistic and behaviour should be fixed either in the governor
		* or in the MCPM back-ends.
		* To make this driver 100% generic the number of states and the exit_latency
		* target_residency values must be obtained from device tree bindings.
		*
		* exit_latency: refers to the TC2 vexpress test chip and depends on the
		* current cluster operating point. It is the time it takes to get the CPU
		* up and running when the CPU is powered up on cluster wake-up from shutdown.
		* Current values for big and LITTLE clusters are provided for clusters
		* running at default operating points.
		*
		* target_residency: it is the minimum amount of time the cluster has
		* to be down to break even in terms of power consumption. cluster
		* shutdown has inherent dynamic power costs (L2 writebacks to DRAM
		* being the main factor) that depend on the current operating points.
		* The current values for both clusters are provided for a CPU whose half
		* of L2 lines are dirty and require cleaning to DRAM, and takes into
		* account leakage static power values related to the vexpress TC2 testchip.
		*/
		static struct cpuidle_driver bl_idle_little_driver = {
		.name = "little_idle",
		.owner = THIS_MODULE,
		.states[0] = ARM_CPUIDLE_WFI_STATE,
		.states[1] = {
		.enter = bl_enter_powerdown,
		.exit_latency = 700,
		.target_residency = 2500,
		.flags = CPUIDLE_FLAG_TIME_VALID \|
		CPUIDLE_FLAG_TIMER_STOP,
		.name = "C1",
		.desc = "ARM little-cluster power down",
		},
		.state_count = 2,
		};

		static struct cpuidle_driver bl_idle_big_driver = {
		.name = "big_idle",
		.owner = THIS_MODULE,
		.states[0] = ARM_CPUIDLE_WFI_STATE,
		.states[1] = {
		.enter = bl_enter_powerdown,
		.exit_latency = 500,
		.target_residency = 2000,
		.flags = CPUIDLE_FLAG_TIME_VALID \|
		CPUIDLE_FLAG_TIMER_STOP,
		.name = "C1",
		.desc = "ARM big-cluster power down",
		},
		.state_count = 2,
		};

		/*
		* notrace prevents trace shims from getting inserted where they
		* should not. Global jumps and ldrex/strex must not be inserted
		* in power down sequences where caches and MMU may be turned off.
		*/
		static int notrace bl_powerdown_finisher(unsigned long arg)
		{
		/* MCPM works with HW CPU identifiers */
		unsigned int mpidr = read_cpuid_mpidr();
		unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
		unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);

		mcpm_set_entry_vector(cpu, cluster, cpu_resume);

		/*
		* Residency value passed to mcpm_cpu_suspend back-end
		* has to be given clear semantics. Set to 0 as a
		* temporary value.
		*/
		mcpm_cpu_suspend(0);

		/* return value != 0 means failure */
		return 1;
		}

		/**
		* bl_enter_powerdown - Programs CPU to enter the specified state
		* @dev: cpuidle device
		* @drv: The target state to be programmed
		* @idx: state index
		*
		* Called from the CPUidle framework to program the device to the
		* specified target state selected by the governor.
		*/
		static int bl_enter_powerdown(struct cpuidle_device *dev,
		struct cpuidle_driver *drv, int idx)
		{
		cpu_pm_enter();

		cpu_suspend(0, bl_powerdown_finisher);

		/* signals the MCPM core that CPU is out of low power state */
		mcpm_cpu_powered_up();

		cpu_pm_exit();

		return idx;
		}

		static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int cpu_id)
		{
		struct cpuinfo_arm *cpu_info;
		struct cpumask *cpumask;
		unsigned long cpuid;
		int cpu;

		cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
		if (!cpumask)
		return -ENOMEM;

		for_each_possible_cpu(cpu) {
		cpu_info = &per_cpu(cpu_data, cpu);
		cpuid = is_smp() ? cpu_info->cpuid : read_cpuid_id();

		/* read cpu id part number */
		if ((cpuid & 0xFFF0) == cpu_id)
		cpumask_set_cpu(cpu, cpumask);
		}

		drv->cpumask = cpumask;

		return 0;
		}

		static int __init bl_idle_init(void)
		{
		int ret;

		/*
		* Initialize the driver just for a compliant set of machines
		*/
		if (!of_machine_is_compatible("arm,vexpress,v2p-ca15_a7"))
		return -ENODEV;
		/*
		* For now the differentiation between little and big cores
		* is based on the part number. A7 cores are considered little
		* cores, A15 are considered big cores. This distinction may
		* evolve in the future with a more generic matching approach.
		*/
		ret = bl_idle_driver_init(&bl_idle_little_driver,
		ARM_CPU_PART_CORTEX_A7);
		if (ret)
		return ret;

		ret = bl_idle_driver_init(&bl_idle_big_driver, ARM_CPU_PART_CORTEX_A15);
		if (ret)
		goto out_uninit_little;

		ret = cpuidle_register(&bl_idle_little_driver, NULL);
		if (ret)
		goto out_uninit_big;

		ret = cpuidle_register(&bl_idle_big_driver, NULL);
		if (ret)
		goto out_unregister_little;

		return 0;

		out_unregister_little:
		cpuidle_unregister(&bl_idle_little_driver);
		out_uninit_big:
		kfree(bl_idle_big_driver.cpumask);
		out_uninit_little:
		kfree(bl_idle_little_driver.cpumask);

		return ret;
		}
		device_initcall(bl_idle_init);

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