Commit a35c6322 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'drivers-for-linus' of git://

Pull ARM SoC driver update from Kevin Hilman:
 "This contains the ARM SoC related driver updates for v3.12.  The only
  thing this cycle are core PM updates and CPUidle support for ARM's TC2
  big.LITTLE development platform"

* tag 'drivers-for-linus' of git://
  cpuidle: big.LITTLE: vexpress-TC2 CPU idle driver
  ARM: vexpress: tc2: disable GIC CPU IF in tc2_pm_suspend
  drivers: irq-chip: irq-gic: introduce gic_cpu_if_down()
parents bef4a0ab 158a71f8
......@@ -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
M: Lorenzo Pieralisi <>
M: Daniel Lezcano <>
T: git://
S: Maintained
F: drivers/cpuidle/cpuidle-big_little.c
M: Rafael J. Wysocki <>
M: Daniel Lezcano <>
......@@ -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));
......@@ -27,3 +27,13 @@ config ARM_U8500_CPUIDLE
Select this to enable cpuidle for ST-E u8500 processors
bool "Support for ARM big.LITTLE processors"
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.
......@@ -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
* Copyright (c) 2013 ARM/Linaro
* Authors: Daniel Lezcano <>
* Lorenzo Pieralisi <>
* Nicolas Pitre <>
* 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 <>
* Maintainer: Daniel Lezcano <>
#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[1] = {
.enter = bl_enter_powerdown,
.exit_latency = 700,
.target_residency = 2500,
.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[1] = {
.enter = bl_enter_powerdown,
.exit_latency = 500,
.target_residency = 2000,
.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.
/* 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_suspend(0, bl_powerdown_finisher);
/* signals the MCPM core that CPU is out of low power state */
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,
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;
return ret;
......@@ -453,6 +453,12 @@ static void gic_cpu_init(struct gic_chip_data *gic)
writel_relaxed(1, base + GIC_CPU_CTRL);
void gic_cpu_if_down(void)
void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
* Saves the GIC distributor registers during suspend or idle. Must be called
......@@ -66,6 +66,7 @@ extern struct irq_chip gic_arch_extn;
void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
u32 offset, struct device_node *);
void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
void gic_cpu_if_down(void);
static inline void gic_init(unsigned int nr, int start,
void __iomem *dist , void __iomem *cpu)
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