Commit 712eddf7 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz Committed by Kukjin Kim

cpuidle: exynos: add coupled cpuidle support for exynos4210

The following patch adds coupled cpuidle support for Exynos4210 to
an existing cpuidle-exynos driver.  As a result it enables AFTR mode
to be used by default on Exynos4210 without the need to hot unplug
CPU1 first.

The patch is heavily based on earlier cpuidle-exynos4210 driver from
Daniel Lezcano:

http://www.spinics.net/lists/linux-samsung-soc/msg28134.html

Changes from Daniel's code include:
- porting code to current kernels
- fixing it to work on my setup (by using S5P_INFORM register
  instead of S5P_VA_SYSRAM one on Revison 1.1 and retrying poking
  CPU1 out of the BOOT ROM if necessary)
- fixing rare lockup caused by waiting for CPU1 to get stuck in
  the BOOT ROM (CPU hotplug code in arch/arm/mach-exynos/platsmp.c
  doesn't require this and works fine)
- moving Exynos specific code to arch/arm/mach-exynos/pm.c
- using cpu_boot_reg_base() helper instead of BOOT_VECTOR macro
- using exynos_cpu_*() helpers instead of accessing registers
  directly
- using arch_send_wakeup_ipi_mask() instead of dsb_sev()
  (this matches CPU hotplug code in arch/arm/mach-exynos/platsmp.c)
- integrating separate exynos4210-cpuidle driver into existing
  exynos-cpuidle one

Cc: Colin Cross <ccross@google.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene@kernel.org>
parent 865e8b76
...@@ -13,6 +13,7 @@ ...@@ -13,6 +13,7 @@
#define __ARCH_ARM_MACH_EXYNOS_COMMON_H #define __ARCH_ARM_MACH_EXYNOS_COMMON_H
#include <linux/of.h> #include <linux/of.h>
#include <linux/platform_data/cpuidle-exynos.h>
#define EXYNOS3250_SOC_ID 0xE3472000 #define EXYNOS3250_SOC_ID 0xE3472000
#define EXYNOS3_SOC_MASK 0xFFFFF000 #define EXYNOS3_SOC_MASK 0xFFFFF000
...@@ -150,8 +151,11 @@ extern void exynos_pm_central_suspend(void); ...@@ -150,8 +151,11 @@ extern void exynos_pm_central_suspend(void);
extern int exynos_pm_central_resume(void); extern int exynos_pm_central_resume(void);
extern void exynos_enter_aftr(void); extern void exynos_enter_aftr(void);
extern struct cpuidle_exynos_data cpuidle_coupled_exynos_data;
extern void s5p_init_cpu(void __iomem *cpuid_addr); extern void s5p_init_cpu(void __iomem *cpuid_addr);
extern unsigned int samsung_rev(void); extern unsigned int samsung_rev(void);
extern void __iomem *cpu_boot_reg_base(void);
static inline void pmu_raw_writel(u32 val, u32 offset) static inline void pmu_raw_writel(u32 val, u32 offset)
{ {
......
...@@ -246,6 +246,10 @@ static void __init exynos_dt_machine_init(void) ...@@ -246,6 +246,10 @@ static void __init exynos_dt_machine_init(void)
if (!IS_ENABLED(CONFIG_SMP)) if (!IS_ENABLED(CONFIG_SMP))
exynos_sysram_init(); exynos_sysram_init();
#ifdef CONFIG_ARM_EXYNOS_CPUIDLE
if (of_machine_is_compatible("samsung,exynos4210"))
exynos_cpuidle.dev.platform_data = &cpuidle_coupled_exynos_data;
#endif
if (of_machine_is_compatible("samsung,exynos4210") || if (of_machine_is_compatible("samsung,exynos4210") ||
of_machine_is_compatible("samsung,exynos4212") || of_machine_is_compatible("samsung,exynos4212") ||
(of_machine_is_compatible("samsung,exynos4412") && (of_machine_is_compatible("samsung,exynos4412") &&
......
...@@ -194,7 +194,7 @@ int exynos_cluster_power_state(int cluster) ...@@ -194,7 +194,7 @@ int exynos_cluster_power_state(int cluster)
S5P_CORE_LOCAL_PWR_EN); S5P_CORE_LOCAL_PWR_EN);
} }
static inline void __iomem *cpu_boot_reg_base(void) void __iomem *cpu_boot_reg_base(void)
{ {
if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1) if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
return pmu_base_addr + S5P_INFORM5; return pmu_base_addr + S5P_INFORM5;
......
...@@ -179,3 +179,125 @@ void exynos_enter_aftr(void) ...@@ -179,3 +179,125 @@ void exynos_enter_aftr(void)
cpu_pm_exit(); cpu_pm_exit();
} }
static atomic_t cpu1_wakeup = ATOMIC_INIT(0);
static int exynos_cpu0_enter_aftr(void)
{
int ret = -1;
/*
* If the other cpu is powered on, we have to power it off, because
* the AFTR state won't work otherwise
*/
if (cpu_online(1)) {
/*
* We reach a sync point with the coupled idle state, we know
* the other cpu will power down itself or will abort the
* sequence, let's wait for one of these to happen
*/
while (exynos_cpu_power_state(1)) {
/*
* The other cpu may skip idle and boot back
* up again
*/
if (atomic_read(&cpu1_wakeup))
goto abort;
/*
* The other cpu may bounce through idle and
* boot back up again, getting stuck in the
* boot rom code
*/
if (__raw_readl(cpu_boot_reg_base()) == 0)
goto abort;
cpu_relax();
}
}
exynos_enter_aftr();
ret = 0;
abort:
if (cpu_online(1)) {
/*
* Set the boot vector to something non-zero
*/
__raw_writel(virt_to_phys(exynos_cpu_resume),
cpu_boot_reg_base());
dsb();
/*
* Turn on cpu1 and wait for it to be on
*/
exynos_cpu_power_up(1);
while (exynos_cpu_power_state(1) != S5P_CORE_LOCAL_PWR_EN)
cpu_relax();
while (!atomic_read(&cpu1_wakeup)) {
/*
* Poke cpu1 out of the boot rom
*/
__raw_writel(virt_to_phys(exynos_cpu_resume),
cpu_boot_reg_base());
arch_send_wakeup_ipi_mask(cpumask_of(1));
}
}
return ret;
}
static int exynos_wfi_finisher(unsigned long flags)
{
cpu_do_idle();
return -1;
}
static int exynos_cpu1_powerdown(void)
{
int ret = -1;
/*
* Idle sequence for cpu1
*/
if (cpu_pm_enter())
goto cpu1_aborted;
/*
* Turn off cpu 1
*/
exynos_cpu_power_down(1);
ret = cpu_suspend(0, exynos_wfi_finisher);
cpu_pm_exit();
cpu1_aborted:
dsb();
/*
* Notify cpu 0 that cpu 1 is awake
*/
atomic_set(&cpu1_wakeup, 1);
return ret;
}
static void exynos_pre_enter_aftr(void)
{
__raw_writel(virt_to_phys(exynos_cpu_resume), cpu_boot_reg_base());
}
static void exynos_post_enter_aftr(void)
{
atomic_set(&cpu1_wakeup, 0);
}
struct cpuidle_exynos_data cpuidle_coupled_exynos_data = {
.cpu0_enter_aftr = exynos_cpu0_enter_aftr,
.cpu1_powerdown = exynos_cpu1_powerdown,
.pre_enter_aftr = exynos_pre_enter_aftr,
.post_enter_aftr = exynos_post_enter_aftr,
};
...@@ -55,6 +55,7 @@ config ARM_AT91_CPUIDLE ...@@ -55,6 +55,7 @@ config ARM_AT91_CPUIDLE
config ARM_EXYNOS_CPUIDLE config ARM_EXYNOS_CPUIDLE
bool "Cpu Idle Driver for the Exynos processors" bool "Cpu Idle Driver for the Exynos processors"
depends on ARCH_EXYNOS depends on ARCH_EXYNOS
select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
help help
Select this to enable cpuidle for Exynos processors Select this to enable cpuidle for Exynos processors
......
/* linux/arch/arm/mach-exynos/cpuidle.c /*
* * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com * http://www.samsung.com
* *
* Coupled cpuidle support based on the work of:
* Colin Cross <ccross@android.com>
* Daniel Lezcano <daniel.lezcano@linaro.org>
*
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. * published by the Free Software Foundation.
...@@ -13,13 +16,49 @@ ...@@ -13,13 +16,49 @@
#include <linux/export.h> #include <linux/export.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/platform_device.h> #include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/platform_data/cpuidle-exynos.h>
#include <asm/proc-fns.h> #include <asm/proc-fns.h>
#include <asm/suspend.h> #include <asm/suspend.h>
#include <asm/cpuidle.h> #include <asm/cpuidle.h>
static atomic_t exynos_idle_barrier;
static struct cpuidle_exynos_data *exynos_cpuidle_pdata;
static void (*exynos_enter_aftr)(void); static void (*exynos_enter_aftr)(void);
static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
int ret;
exynos_cpuidle_pdata->pre_enter_aftr();
/*
* Waiting all cpus to reach this point at the same moment
*/
cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
/*
* Both cpus will reach this point at the same time
*/
ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
: exynos_cpuidle_pdata->cpu0_enter_aftr();
if (ret)
index = ret;
/*
* Waiting all cpus to finish the power sequence before going further
*/
cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
exynos_cpuidle_pdata->post_enter_aftr();
return index;
}
static int exynos_enter_lowpower(struct cpuidle_device *dev, static int exynos_enter_lowpower(struct cpuidle_device *dev,
struct cpuidle_driver *drv, struct cpuidle_driver *drv,
int index) int index)
...@@ -55,13 +94,40 @@ static struct cpuidle_driver exynos_idle_driver = { ...@@ -55,13 +94,40 @@ static struct cpuidle_driver exynos_idle_driver = {
.safe_state_index = 0, .safe_state_index = 0,
}; };
static struct cpuidle_driver exynos_coupled_idle_driver = {
.name = "exynos_coupled_idle",
.owner = THIS_MODULE,
.states = {
[0] = ARM_CPUIDLE_WFI_STATE,
[1] = {
.enter = exynos_enter_coupled_lowpower,
.exit_latency = 5000,
.target_residency = 10000,
.flags = CPUIDLE_FLAG_COUPLED |
CPUIDLE_FLAG_TIMER_STOP,
.name = "C1",
.desc = "ARM power down",
},
},
.state_count = 2,
.safe_state_index = 0,
};
static int exynos_cpuidle_probe(struct platform_device *pdev) static int exynos_cpuidle_probe(struct platform_device *pdev)
{ {
int ret; int ret;
exynos_enter_aftr = (void *)(pdev->dev.platform_data); if (of_machine_is_compatible("samsung,exynos4210")) {
exynos_cpuidle_pdata = pdev->dev.platform_data;
ret = cpuidle_register(&exynos_coupled_idle_driver,
cpu_possible_mask);
} else {
exynos_enter_aftr = (void *)(pdev->dev.platform_data);
ret = cpuidle_register(&exynos_idle_driver, NULL);
}
ret = cpuidle_register(&exynos_idle_driver, NULL);
if (ret) { if (ret) {
dev_err(&pdev->dev, "failed to register cpuidle driver\n"); dev_err(&pdev->dev, "failed to register cpuidle driver\n");
return ret; return ret;
......
/*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* 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.
*/
#ifndef __CPUIDLE_EXYNOS_H
#define __CPUIDLE_EXYNOS_H
struct cpuidle_exynos_data {
int (*cpu0_enter_aftr)(void);
int (*cpu1_powerdown)(void);
void (*pre_enter_aftr)(void);
void (*post_enter_aftr)(void);
};
#endif
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