[PATCH V3 1/6] ARM: exynos: Add AFTR mode cpuidle state on EXYNOS4210
Inderpal Singh
inderpal.singh at linaro.org
Wed Nov 23 23:07:39 EST 2011
Hi Amit,
On 22 November 2011 15:05, Amit Daniel Kachhap <amit.kachhap at linaro.org> wrote:
>
> This patch adds support AFTR(ARM OFF TOP RUNNING) mode in
> cpuidle driver. L2 cache keeps their data in this mode.
> This patch ports the code to the latest interfaces to
> save/restore CPU state inclusive of CPU PM notifiers, l2
> resume and cpu_suspend/resume.
>
> Signed-off-by: Jaecheol Lee <jc.lee at samsung.com>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> Signed-off-by: Amit Daniel Kachhap <amit.kachhap at linaro.org>
> ---
> arch/arm/mach-exynos/cpuidle.c | 152 ++++++++++++++++++++++++++++++-
> arch/arm/mach-exynos/include/mach/pmu.h | 2 +
> 2 files changed, 151 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c
> index 21403c8..89afa93 100644
> --- a/arch/arm/mach-exynos/cpuidle.c
> +++ b/arch/arm/mach-exynos/cpuidle.c
> @@ -12,15 +12,37 @@
> #include <linux/module.h>
> #include <linux/init.h>
> #include <linux/cpuidle.h>
> +#include <linux/cpu_pm.h>
> #include <linux/io.h>
> #include <linux/export.h>
> #include <linux/time.h>
>
> #include <asm/proc-fns.h>
> +#include <asm/smp_scu.h>
> +#include <asm/suspend.h>
> +#include <asm/unified.h>
> +#include <mach/regs-pmu.h>
> +#include <mach/pmu.h>
> +
> +#include <plat/exynos4.h>
> +#include <plat/cpu.h>
> +
> +#define REG_DIRECTGO_ADDR (samsung_rev() == EXYNOS4210_REV_1_1 ? \
> + S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
> + (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
> +#define REG_DIRECTGO_FLAG (samsung_rev() == EXYNOS4210_REV_1_1 ? \
> + S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
> + (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
> +
> +#define S5P_CHECK_AFTR (samsung_rev() == EXYNOS4210_REV_1_0 ? \
> + 0xBAD00000 : 0xFCBA0D10)
>
> static int exynos4_enter_idle(struct cpuidle_device *dev,
> struct cpuidle_driver *drv,
> int index);
> +static int exynos4_enter_lowpower(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index);
>
> static struct cpuidle_state exynos4_cpuidle_set[] = {
> [0] = {
> @@ -28,9 +50,17 @@ static struct cpuidle_state exynos4_cpuidle_set[] = {
> .exit_latency = 1,
> .target_residency = 100000,
> .flags = CPUIDLE_FLAG_TIME_VALID,
> - .name = "IDLE",
> + .name = "C0",
> .desc = "ARM clock gating(WFI)",
> },
> + [1] = {
> + .enter = exynos4_enter_lowpower,
> + .exit_latency = 300,
> + .target_residency = 100000,
> + .flags = CPUIDLE_FLAG_TIME_VALID,
> + .name = "C1",
> + .desc = "ARM power down",
> + },
> };
>
> static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
> @@ -40,9 +70,101 @@ static struct cpuidle_driver exynos4_idle_driver = {
> .owner = THIS_MODULE,
> };
>
> +/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
> +static void exynos4_set_wakeupmask(void)
> +{
> + __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
> +}
> +
> +static unsigned int g_pwr_ctrl, g_diag_reg;
> +
> +static void save_cpu_arch_register(void)
> +{
> + /*read power control register*/
> + asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
> + /*read diagnostic register*/
> + asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
> + return;
> +}
> +
> +static void restore_cpu_arch_register(void)
> +{
> + /*write power control register*/
> + asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
> + /*write diagnostic register*/
> + asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
> + return;
> +}
> +
> +static int idle_finisher(unsigned long flags)
> +{
> + cpu_do_idle();
> + return 1;
> +}
> +
> +static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + struct timeval before, after;
> + int idle_time;
> + unsigned long tmp;
> +
> + local_irq_disable();
> + do_gettimeofday(&before);
> +
> + exynos4_set_wakeupmask();
> +
> + /* Set value of power down register for aftr mode */
> + exynos4_sys_powerdown_conf(SYS_AFTR);
> +
> + __raw_writel(BSYM(virt_to_phys(s3c_cpu_resume)),
> + REG_DIRECTGO_ADDR);
> + __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
> +
> + save_cpu_arch_register();
> +
> + /* Setting Central Sequence Register for power down mode */
> + tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
> + tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
> + __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
> +
> + cpu_pm_enter();
> + cpu_suspend(0, idle_finisher);
> +
> + scu_enable(S5P_VA_SCU);
> + cpu_pm_exit();
> +
> + restore_cpu_arch_register();
> +
> + /*
> + * If PMU failed while entering sleep mode, WFI will be
> + * ignored by PMU and then exiting cpu_do_idle().
> + * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
> + * in this situation.
> + */
> + tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
> + if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
> + tmp |= S5P_CENTRAL_LOWPWR_CFG;
> + __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
> + }
> +
> + /* Clear wakeup state register */
> + __raw_writel(0x0, S5P_WAKEUP_STAT);
> +
> + do_gettimeofday(&after);
> +
> + local_irq_enable();
> + idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
> + (after.tv_usec - before.tv_usec);
> +
> + dev->last_residency = idle_time;
> + return index;
> +}
> +
> static int exynos4_enter_idle(struct cpuidle_device *dev,
> struct cpuidle_driver *drv,
> - int index)
> + int index)
> {
> struct timeval before, after;
> int idle_time;
> @@ -61,6 +183,24 @@ static int exynos4_enter_idle(struct cpuidle_device *dev,
> return index;
> }
>
> +static int exynos4_enter_lowpower(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + int new_index = index;
> +
> + /* This mode only can be entered when other core's are offline */
> + if (num_online_cpus() > 1) {
> + new_index = drv->safe_state_index;
> + BUG_ON(new_index > drv->state_count);
drv->state_count is not being initialized anywhere.
Moreover, do we need BUG_ON? As we now return index to the cpuidle framework,
can we not enter C0 and framework will know that we entered C0 instead of C1 ?
> + }
> +
> + if (new_index == 0)
> + return exynos4_enter_idle(dev, drv, new_index);
> + else
> + return exynos4_enter_core0_aftr(dev, drv, new_index);
> +}
> +
> static int __init exynos4_init_cpuidle(void)
> {
> int i, max_cpuidle_state, cpu_id;
> @@ -75,19 +215,25 @@ static int __init exynos4_init_cpuidle(void)
> memcpy(&drv->states[i], &exynos4_cpuidle_set[i],
> sizeof(struct cpuidle_state));
> }
> + drv->safe_state_index = 0;
> cpuidle_register_driver(&exynos4_idle_driver);
>
> for_each_cpu(cpu_id, cpu_online_mask) {
> device = &per_cpu(exynos4_cpuidle_device, cpu_id);
> device->cpu = cpu_id;
>
> - device->state_count = drv->state_count;
> + if (cpu_id == 0)
> + device->state_count = (sizeof(exynos4_cpuidle_set) /
> + sizeof(struct cpuidle_state));
> + else
> + device->state_count = 1; /* Support IDLE only */
>
> if (cpuidle_register_device(device)) {
> printk(KERN_ERR "CPUidle register device failed\n,");
> return -EIO;
> }
> }
> +
> return 0;
> }
> device_initcall(exynos4_init_cpuidle);
> diff --git a/arch/arm/mach-exynos/include/mach/pmu.h b/arch/arm/mach-exynos/include/mach/pmu.h
> index 632dd56..e76b7fa 100644
> --- a/arch/arm/mach-exynos/include/mach/pmu.h
> +++ b/arch/arm/mach-exynos/include/mach/pmu.h
> @@ -22,11 +22,13 @@ enum sys_powerdown {
> NUM_SYS_POWERDOWN,
> };
>
> +extern unsigned long l2x0_regs_phys;
> struct exynos4_pmu_conf {
> void __iomem *reg;
> unsigned int val[NUM_SYS_POWERDOWN];
> };
>
> extern void exynos4_sys_powerdown_conf(enum sys_powerdown mode);
> +extern void s3c_cpu_resume(void);
>
> #endif /* __ASM_ARCH_PMU_H */
> --
> 1.7.1
>
> --
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