diff options
Diffstat (limited to 'drivers/devfreq')
| -rw-r--r-- | drivers/devfreq/tegra30-devfreq.c | 180 |
1 files changed, 155 insertions, 25 deletions
diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c index 9ccde64be0a0..2d720e7e2236 100644 --- a/drivers/devfreq/tegra30-devfreq.c +++ b/drivers/devfreq/tegra30-devfreq.c @@ -17,6 +17,7 @@ #include <linux/platform_device.h> #include <linux/pm_opp.h> #include <linux/reset.h> +#include <linux/workqueue.h> #include "governor.h" @@ -34,6 +35,8 @@ #define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30) #define ACTMON_DEV_CTRL_ENB BIT(31) +#define ACTMON_DEV_CTRL_STOP 0x00000000 + #define ACTMON_DEV_UPPER_WMARK 0x4 #define ACTMON_DEV_LOWER_WMARK 0x8 #define ACTMON_DEV_INIT_AVG 0xc @@ -159,7 +162,10 @@ struct tegra_devfreq { struct clk *emc_clock; unsigned long max_freq; unsigned long cur_freq; - struct notifier_block rate_change_nb; + struct notifier_block clk_rate_change_nb; + + struct delayed_work cpufreq_update_work; + struct notifier_block cpu_rate_change_nb; struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)]; @@ -303,22 +309,32 @@ static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra, return 0; } +static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + unsigned int avg_sustain_coef; + unsigned long target_freq; + + target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; + avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; + target_freq = do_percent(target_freq, avg_sustain_coef); + target_freq += dev->boost_freq; + + return target_freq; +} + static void actmon_update_target(struct tegra_devfreq *tegra, struct tegra_devfreq_device *dev) { unsigned long cpu_freq = 0; unsigned long static_cpu_emc_freq = 0; - unsigned int avg_sustain_coef; if (dev->config->avg_dependency_threshold) { - cpu_freq = cpufreq_get(0); + cpu_freq = cpufreq_quick_get(0); static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); } - dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; - avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; - dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef); - dev->target_freq += dev->boost_freq; + dev->target_freq = actmon_device_target_freq(tegra, dev); if (dev->avg_count >= dev->config->avg_dependency_threshold) dev->target_freq = max(dev->target_freq, static_cpu_emc_freq); @@ -349,8 +365,8 @@ static irqreturn_t actmon_thread_isr(int irq, void *data) return handled ? IRQ_HANDLED : IRQ_NONE; } -static int tegra_actmon_rate_notify_cb(struct notifier_block *nb, - unsigned long action, void *ptr) +static int tegra_actmon_clk_notify_cb(struct notifier_block *nb, + unsigned long action, void *ptr) { struct clk_notifier_data *data = ptr; struct tegra_devfreq *tegra; @@ -360,7 +376,7 @@ static int tegra_actmon_rate_notify_cb(struct notifier_block *nb, if (action != POST_RATE_CHANGE) return NOTIFY_OK; - tegra = container_of(nb, struct tegra_devfreq, rate_change_nb); + tegra = container_of(nb, struct tegra_devfreq, clk_rate_change_nb); tegra->cur_freq = data->new_rate / KHZ; @@ -373,6 +389,79 @@ static int tegra_actmon_rate_notify_cb(struct notifier_block *nb, return NOTIFY_OK; } +static void tegra_actmon_delayed_update(struct work_struct *work) +{ + struct tegra_devfreq *tegra = container_of(work, struct tegra_devfreq, + cpufreq_update_work.work); + + mutex_lock(&tegra->devfreq->lock); + update_devfreq(tegra->devfreq); + mutex_unlock(&tegra->devfreq->lock); +} + +static unsigned long +tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra, + unsigned int cpu_freq) +{ + unsigned long static_cpu_emc_freq, dev_freq; + + /* check whether CPU's freq is taken into account at all */ + if (tegra->devices[MCCPU].avg_count < + tegra->devices[MCCPU].config->avg_dependency_threshold) + return 0; + + static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); + dev_freq = actmon_device_target_freq(tegra, &tegra->devices[MCCPU]); + + if (dev_freq >= static_cpu_emc_freq) + return 0; + + return static_cpu_emc_freq; +} + +static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, + unsigned long action, void *ptr) +{ + struct cpufreq_freqs *freqs = ptr; + struct tegra_devfreq *tegra; + unsigned long old, new, delay; + + if (action != CPUFREQ_POSTCHANGE) + return NOTIFY_OK; + + tegra = container_of(nb, struct tegra_devfreq, cpu_rate_change_nb); + + /* + * Quickly check whether CPU frequency should be taken into account + * at all, without blocking CPUFreq's core. + */ + if (mutex_trylock(&tegra->devfreq->lock)) { + old = tegra_actmon_cpufreq_contribution(tegra, freqs->old); + new = tegra_actmon_cpufreq_contribution(tegra, freqs->new); + mutex_unlock(&tegra->devfreq->lock); + + /* + * If CPU's frequency shouldn't be taken into account at + * the moment, then there is no need to update the devfreq's + * state because ISR will re-check CPU's frequency on the + * next interrupt. + */ + if (old == new) + return NOTIFY_OK; + } + + /* + * CPUFreq driver should support CPUFREQ_ASYNC_NOTIFICATION in order + * to allow asynchronous notifications. This means we can't block + * here for too long, otherwise CPUFreq's core will complain with a + * warning splat. + */ + delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); + schedule_delayed_work(&tegra->cpufreq_update_work, delay); + + return NOTIFY_OK; +} + static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, struct tegra_devfreq_device *dev) { @@ -405,9 +494,22 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, device_writel(dev, val, ACTMON_DEV_CTRL); } -static void tegra_actmon_start(struct tegra_devfreq *tegra) +static void tegra_actmon_stop_devices(struct tegra_devfreq *tegra) +{ + struct tegra_devfreq_device *dev = tegra->devices; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++, dev++) { + device_writel(dev, ACTMON_DEV_CTRL_STOP, ACTMON_DEV_CTRL); + device_writel(dev, ACTMON_INTR_STATUS_CLEAR, + ACTMON_DEV_INTR_STATUS); + } +} + +static int tegra_actmon_start(struct tegra_devfreq *tegra) { unsigned int i; + int err; actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, ACTMON_GLB_PERIOD_CTRL); @@ -415,20 +517,41 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra) for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_configure_device(tegra, &tegra->devices[i]); + /* + * We are estimating CPU's memory bandwidth requirement based on + * amount of memory accesses and system's load, judging by CPU's + * frequency. We also don't want to receive events about CPU's + * frequency transaction when governor is stopped, hence notifier + * is registered dynamically. + */ + err = cpufreq_register_notifier(&tegra->cpu_rate_change_nb, + CPUFREQ_TRANSITION_NOTIFIER); + if (err) { + dev_err(tegra->devfreq->dev.parent, + "Failed to register rate change notifier: %d\n", err); + goto err_stop; + } + enable_irq(tegra->irq); + + return 0; + +err_stop: + tegra_actmon_stop_devices(tegra); + + return err; } static void tegra_actmon_stop(struct tegra_devfreq *tegra) { - unsigned int i; - disable_irq(tegra->irq); - for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { - device_writel(&tegra->devices[i], 0x00000000, ACTMON_DEV_CTRL); - device_writel(&tegra->devices[i], ACTMON_INTR_STATUS_CLEAR, - ACTMON_DEV_INTR_STATUS); - } + cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, + CPUFREQ_TRANSITION_NOTIFIER); + + cancel_delayed_work_sync(&tegra->cpufreq_update_work); + + tegra_actmon_stop_devices(tegra); } static int tegra_devfreq_target(struct device *dev, unsigned long *freq, @@ -536,6 +659,7 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, unsigned int event, void *data) { struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent); + int ret = 0; /* * Couple devfreq-device with the governor early because it is @@ -546,7 +670,7 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, switch (event) { case DEVFREQ_GOV_START: devfreq_monitor_start(devfreq); - tegra_actmon_start(tegra); + ret = tegra_actmon_start(tegra); break; case DEVFREQ_GOV_STOP: @@ -561,11 +685,11 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, case DEVFREQ_GOV_RESUME: devfreq_monitor_resume(devfreq); - tegra_actmon_start(tegra); + ret = tegra_actmon_start(tegra); break; } - return 0; + return ret; } static struct devfreq_governor tegra_devfreq_governor = { @@ -672,8 +796,14 @@ static int tegra_devfreq_probe(struct platform_device *pdev) platform_set_drvdata(pdev, tegra); - tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb; - err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb); + tegra->cpu_rate_change_nb.notifier_call = tegra_actmon_cpu_notify_cb; + + INIT_DELAYED_WORK(&tegra->cpufreq_update_work, + tegra_actmon_delayed_update); + + tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb; + err = clk_notifier_register(tegra->emc_clock, + &tegra->clk_rate_change_nb); if (err) { dev_err(&pdev->dev, "Failed to register rate change notifier\n"); @@ -701,7 +831,7 @@ remove_governor: devfreq_remove_governor(&tegra_devfreq_governor); unreg_notifier: - clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb); + clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); remove_opps: dev_pm_opp_remove_all_dynamic(&pdev->dev); @@ -719,7 +849,7 @@ static int tegra_devfreq_remove(struct platform_device *pdev) devfreq_remove_device(tegra->devfreq); devfreq_remove_governor(&tegra_devfreq_governor); - clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb); + clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); dev_pm_opp_remove_all_dynamic(&pdev->dev); reset_control_reset(tegra->reset); |