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: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Colin Cross <ccross@xxxxxxxxxx> Cc: Kukjin Kim <kgene.kim@xxxxxxxxxxx> Cc: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> Cc: Tomasz Figa <tomasz.figa@xxxxxxxxx> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> --- arch/arm/mach-exynos/common.h | 4 + arch/arm/mach-exynos/exynos.c | 4 + arch/arm/mach-exynos/platsmp.c | 2 +- arch/arm/mach-exynos/pm.c | 122 +++++++++++++++++++++++++++ drivers/cpuidle/Kconfig.arm | 1 + drivers/cpuidle/cpuidle-exynos.c | 62 ++++++++++++-- include/linux/platform_data/cpuidle-exynos.h | 20 +++++ 7 files changed, 209 insertions(+), 6 deletions(-) create mode 100644 include/linux/platform_data/cpuidle-exynos.h diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h index d4d09bc..f208a60 100644 --- a/arch/arm/mach-exynos/common.h +++ b/arch/arm/mach-exynos/common.h @@ -14,6 +14,7 @@ #include <linux/reboot.h> #include <linux/of.h> +#include <linux/platform_data/cpuidle-exynos.h> #define EXYNOS3250_SOC_ID 0xE3472000 #define EXYNOS3_SOC_MASK 0xFFFFF000 @@ -168,8 +169,11 @@ extern void exynos_pm_central_suspend(void); extern int exynos_pm_central_resume(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 unsigned int samsung_rev(void); +extern void __iomem *cpu_boot_reg_base(void); static inline void pmu_raw_writel(u32 val, u32 offset) { diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c index a487e59..4f4eb9e 100644 --- a/arch/arm/mach-exynos/exynos.c +++ b/arch/arm/mach-exynos/exynos.c @@ -317,6 +317,10 @@ static void __init exynos_dt_machine_init(void) if (!IS_ENABLED(CONFIG_SMP)) 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") || of_machine_is_compatible("samsung,exynos4212") || (of_machine_is_compatible("samsung,exynos4412") && diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c index adb36a8..0e3ffc9 100644 --- a/arch/arm/mach-exynos/platsmp.c +++ b/arch/arm/mach-exynos/platsmp.c @@ -182,7 +182,7 @@ int exynos_cluster_power_state(int cluster) 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) return pmu_base_addr + S5P_INFORM5; diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c index 4b36ab5..44cc08a 100644 --- a/arch/arm/mach-exynos/pm.c +++ b/arch/arm/mach-exynos/pm.c @@ -178,3 +178,125 @@ void exynos_enter_aftr(void) 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, +}; diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm index 8c16ab2..8e07c94 100644 --- a/drivers/cpuidle/Kconfig.arm +++ b/drivers/cpuidle/Kconfig.arm @@ -55,6 +55,7 @@ config ARM_AT91_CPUIDLE config ARM_EXYNOS_CPUIDLE bool "Cpu Idle Driver for the Exynos processors" depends on ARCH_EXYNOS + select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP help Select this to enable cpuidle for Exynos processors diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c index ba9b34b..4700d5d 100644 --- a/drivers/cpuidle/cpuidle-exynos.c +++ b/drivers/cpuidle/cpuidle-exynos.c @@ -1,8 +1,11 @@ -/* linux/arch/arm/mach-exynos/cpuidle.c - * - * Copyright (c) 2011 Samsung Electronics Co., Ltd. +/* + * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd. * http://www.samsung.com * + * Coupled cpuidle support based on the work of: + * Colin Cross <ccross@xxxxxxxxxxx> + * Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> + * * 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. @@ -13,13 +16,49 @@ #include <linux/export.h> #include <linux/module.h> #include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/platform_data/cpuidle-exynos.h> #include <asm/proc-fns.h> #include <asm/suspend.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 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, struct cpuidle_driver *drv, int index) @@ -58,11 +97,24 @@ static struct cpuidle_driver exynos_idle_driver = { static int exynos_cpuidle_probe(struct platform_device *pdev) { + const struct cpumask *coupled_cpus = NULL; int ret; - exynos_enter_aftr = (void *)(pdev->dev.platform_data); + if (of_machine_is_compatible("samsung,exynos4210")) { + exynos_cpuidle_pdata = pdev->dev.platform_data; + + exynos_idle_driver.states[1].enter = + exynos_enter_coupled_lowpower; + exynos_idle_driver.states[1].exit_latency = 5000; + exynos_idle_driver.states[1].target_residency = 10000; + exynos_idle_driver.states[1].flags |= CPUIDLE_FLAG_COUPLED | + CPUIDLE_FLAG_TIMER_STOP; + + coupled_cpus = 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, coupled_cpus); if (ret) { dev_err(&pdev->dev, "failed to register cpuidle driver\n"); return ret; diff --git a/include/linux/platform_data/cpuidle-exynos.h b/include/linux/platform_data/cpuidle-exynos.h new file mode 100644 index 0000000..bfa40e4 --- /dev/null +++ b/include/linux/platform_data/cpuidle-exynos.h @@ -0,0 +1,20 @@ +/* + * 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 -- 1.8.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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