Loading drivers/devfreq/Kconfig +10 −0 Original line number Diff line number Diff line Loading @@ -80,6 +80,16 @@ config DEVFREQ_GOV_CPUFREQ CPU frequency to device frequency mapping table(s). This governor can be useful for controlling devices such as DDR, cache, CCI, etc. config DEVFREQ_GOV_QCOM_BW_HWMON tristate "HW monitor based governor for device BW" depends on QCOM_BIMC_BWMON help HW monitor based governor for device to DDR bandwidth voting. This governor sets the CPU BW vote by using BIMC counters to monitor the CPU's use of DDR. Since this uses target specific counters it can conflict with existing profiling tools. This governor is unlikely to be useful for non-QCOM devices. config DEVFREQ_GOV_QCOM_CACHE_HWMON tristate "HW monitor based governor for cache frequency" help Loading drivers/devfreq/Makefile +1 −0 Original line number Diff line number Diff line Loading @@ -8,6 +8,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o obj-$(CONFIG_DEVFREQ_GOV_CPUFREQ) += governor_cpufreq.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_ADRENO_TZ) += governor_msm_adreno_tz.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_GPUBW_MON) += governor_bw_vbif.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_BW_HWMON) += governor_bw_hwmon.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_CACHE_HWMON) += governor_cache_hwmon.o # DEVFREQ Drivers Loading drivers/devfreq/governor_bw_hwmon.c 0 → 100644 +440 −0 Original line number Diff line number Diff line /* * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) "bw-hwmon: " fmt #include <linux/kernel.h> #include <linux/sizes.h> #include <linux/module.h> #include <linux/init.h> #include <linux/io.h> #include <linux/delay.h> #include <linux/ktime.h> #include <linux/time.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/mutex.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/of.h> #include <linux/devfreq.h> #include <trace/events/power.h> #include "governor.h" #include "governor_bw_hwmon.h" struct hwmon_node { unsigned int tolerance_percent; unsigned int guard_band_mbps; unsigned int decay_rate; unsigned int io_percent; unsigned int bw_step; unsigned long prev_ab; unsigned long *dev_ab; ktime_t prev_ts; bool mon_started; struct list_head list; void *orig_data; struct bw_hwmon *hw; struct devfreq_governor *gov; struct attribute_group *attr_grp; }; static LIST_HEAD(hwmon_list); static DEFINE_MUTEX(list_lock); static int use_cnt; static DEFINE_MUTEX(state_lock); #define show_attr(name) \ static ssize_t show_##name(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct devfreq *df = to_devfreq(dev); \ struct hwmon_node *hw = df->data; \ return snprintf(buf, PAGE_SIZE, "%u\n", hw->name); \ } #define store_attr(name, _min, _max) \ static ssize_t store_##name(struct device *dev, \ struct device_attribute *attr, const char *buf, \ size_t count) \ { \ struct devfreq *df = to_devfreq(dev); \ struct hwmon_node *hw = df->data; \ int ret; \ unsigned int val; \ ret = sscanf(buf, "%u", &val); \ if (ret != 1) \ return -EINVAL; \ val = max(val, _min); \ val = min(val, _max); \ hw->name = val; \ return count; \ } #define gov_attr(__attr, min, max) \ show_attr(__attr) \ store_attr(__attr, min, max) \ static DEVICE_ATTR(__attr, 0644, show_##__attr, store_##__attr) #define MIN_MS 10U #define MAX_MS 500U static unsigned long measure_bw_and_set_irq(struct hwmon_node *node) { ktime_t ts; unsigned int us; unsigned long mbps; struct bw_hwmon *hw = node->hw; /* * Since we are stopping the counters, we don't want this short work * to be interrupted by other tasks and cause the measurements to be * wrong. Not blocking interrupts to avoid affecting interrupt * latency and since they should be short anyway because they run in * atomic context. */ preempt_disable(); ts = ktime_get(); us = ktime_to_us(ktime_sub(ts, node->prev_ts)); if (!us) us = 1; mbps = hw->meas_bw_and_set_irq(hw, node->tolerance_percent, us); node->prev_ts = ts; preempt_enable(); dev_dbg(hw->df->dev.parent, "BW MBps = %6lu, period = %u\n", mbps, us); trace_bw_hwmon_meas(dev_name(hw->df->dev.parent), mbps, us, 0); return mbps; } static void compute_bw(struct hwmon_node *node, int mbps, unsigned long *freq, unsigned long *ab) { int new_bw; mbps += node->guard_band_mbps; if (mbps > node->prev_ab) { new_bw = mbps; } else { new_bw = mbps * node->decay_rate + node->prev_ab * (100 - node->decay_rate); new_bw /= 100; } node->prev_ab = new_bw; if (ab) *ab = roundup(new_bw, node->bw_step); *freq = (new_bw * 100) / node->io_percent; trace_bw_hwmon_update(dev_name(node->hw->df->dev.parent), new_bw, *freq, 0, 0); } static struct hwmon_node *find_hwmon_node(struct devfreq *df) { struct hwmon_node *node, *found = NULL; mutex_lock(&list_lock); list_for_each_entry(node, &hwmon_list, list) if (node->hw->dev == df->dev.parent || node->hw->of_node == df->dev.parent->of_node || (!node->hw->dev && !node->hw->of_node && node->gov == df->governor)) { found = node; break; } mutex_unlock(&list_lock); return found; } #define TOO_SOON_US (1 * USEC_PER_MSEC) int update_bw_hwmon(struct bw_hwmon *hwmon) { struct devfreq *df; struct hwmon_node *node; ktime_t ts; unsigned int us; int ret; if (!hwmon) return -EINVAL; df = hwmon->df; if (!df) return -ENODEV; node = find_hwmon_node(df); if (!node) return -ENODEV; if (!node->mon_started) return -EBUSY; dev_dbg(df->dev.parent, "Got update request\n"); devfreq_monitor_stop(df); /* * Don't recalc bandwidth if the interrupt comes right after a * previous bandwidth calculation. This is done for two reasons: * * 1. Sampling the BW during a very short duration can result in a * very inaccurate measurement due to very short bursts. * 2. This can only happen if the limit was hit very close to the end * of the previous sample period. Which means the current BW * estimate is not very off and doesn't need to be readjusted. */ ts = ktime_get(); us = ktime_to_us(ktime_sub(ts, node->prev_ts)); if (us > TOO_SOON_US) { mutex_lock(&df->lock); ret = update_devfreq(df); if (ret) dev_err(df->dev.parent, "Unable to update freq on request!\n"); mutex_unlock(&df->lock); } devfreq_monitor_start(df); return 0; } static int start_monitoring(struct devfreq *df) { int ret = 0; unsigned long mbps; struct device *dev = df->dev.parent; struct hwmon_node *node; struct bw_hwmon *hw; struct devfreq_dev_status stat; node = find_hwmon_node(df); if (!node) { dev_err(dev, "Unable to find HW monitor!\n"); return -ENODEV; } hw = node->hw; stat.private_data = NULL; if (df->profile->get_dev_status) ret = df->profile->get_dev_status(df->dev.parent, &stat); if (ret || !stat.private_data) dev_warn(dev, "Device doesn't take AB votes!\n"); else node->dev_ab = stat.private_data; hw->df = df; node->orig_data = df->data; df->data = node; node->prev_ts = ktime_get(); node->prev_ab = 0; mbps = (df->previous_freq * node->io_percent) / 100; ret = hw->start_hwmon(hw, mbps); if (ret) { dev_err(dev, "Unable to start HW monitor!\n"); goto err_start; } devfreq_monitor_start(df); node->mon_started = true; ret = sysfs_create_group(&df->dev.kobj, node->attr_grp); if (ret) goto err_sysfs; return 0; err_sysfs: node->mon_started = false; devfreq_monitor_stop(df); hw->stop_hwmon(hw); err_start: df->data = node->orig_data; node->orig_data = NULL; hw->df = NULL; node->dev_ab = NULL; return ret; } static void stop_monitoring(struct devfreq *df) { struct hwmon_node *node = df->data; struct bw_hwmon *hw = node->hw; sysfs_remove_group(&df->dev.kobj, node->attr_grp); node->mon_started = false; devfreq_monitor_stop(df); hw->stop_hwmon(hw); df->data = node->orig_data; node->orig_data = NULL; hw->df = NULL; /* * Not all governors know about this additional extended device * configuration. To avoid leaving the extended configuration at a * stale state, set it to 0 and let the next governor take it from * there. */ if (node->dev_ab) *node->dev_ab = 0; node->dev_ab = NULL; } static int devfreq_bw_hwmon_get_freq(struct devfreq *df, unsigned long *freq) { unsigned long mbps; struct hwmon_node *node = df->data; mbps = measure_bw_and_set_irq(node); compute_bw(node, mbps, freq, node->dev_ab); return 0; } gov_attr(tolerance_percent, 0U, 30U); gov_attr(guard_band_mbps, 0U, 2000U); gov_attr(decay_rate, 0U, 100U); gov_attr(io_percent, 1U, 100U); gov_attr(bw_step, 50U, 1000U); static struct attribute *dev_attr[] = { &dev_attr_tolerance_percent.attr, &dev_attr_guard_band_mbps.attr, &dev_attr_decay_rate.attr, &dev_attr_io_percent.attr, &dev_attr_bw_step.attr, NULL, }; static struct attribute_group dev_attr_group = { .name = "bw_hwmon", .attrs = dev_attr, }; static int devfreq_bw_hwmon_ev_handler(struct devfreq *df, unsigned int event, void *data) { int ret; unsigned int sample_ms; switch (event) { case DEVFREQ_GOV_START: sample_ms = df->profile->polling_ms; sample_ms = max(MIN_MS, sample_ms); sample_ms = min(MAX_MS, sample_ms); df->profile->polling_ms = sample_ms; ret = start_monitoring(df); if (ret) return ret; dev_dbg(df->dev.parent, "Enabled dev BW HW monitor governor\n"); break; case DEVFREQ_GOV_STOP: stop_monitoring(df); dev_dbg(df->dev.parent, "Disabled dev BW HW monitor governor\n"); break; case DEVFREQ_GOV_INTERVAL: sample_ms = *(unsigned int *)data; sample_ms = max(MIN_MS, sample_ms); sample_ms = min(MAX_MS, sample_ms); devfreq_interval_update(df, &sample_ms); break; } return 0; } static struct devfreq_governor devfreq_gov_bw_hwmon = { .name = "bw_hwmon", .get_target_freq = devfreq_bw_hwmon_get_freq, .event_handler = devfreq_bw_hwmon_ev_handler, }; int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon) { int ret = 0; struct hwmon_node *node; struct attribute_group *attr_grp; if (!hwmon->gov && !hwmon->dev && !hwmon->of_node) return -EINVAL; node = devm_kzalloc(dev, sizeof(*node), GFP_KERNEL); if (!node) return -ENOMEM; if (hwmon->gov) { attr_grp = devm_kzalloc(dev, sizeof(*attr_grp), GFP_KERNEL); if (!attr_grp) return -ENOMEM; hwmon->gov->get_target_freq = devfreq_bw_hwmon_get_freq; hwmon->gov->event_handler = devfreq_bw_hwmon_ev_handler; attr_grp->name = hwmon->gov->name; attr_grp->attrs = dev_attr; node->gov = hwmon->gov; node->attr_grp = attr_grp; } else { node->gov = &devfreq_gov_bw_hwmon; node->attr_grp = &dev_attr_group; } node->tolerance_percent = 10; node->guard_band_mbps = 100; node->decay_rate = 90; node->io_percent = 16; node->bw_step = 190; node->hw = hwmon; mutex_lock(&list_lock); list_add_tail(&node->list, &hwmon_list); mutex_unlock(&list_lock); if (hwmon->gov) { ret = devfreq_add_governor(hwmon->gov); } else { mutex_lock(&state_lock); if (!use_cnt) ret = devfreq_add_governor(&devfreq_gov_bw_hwmon); if (!ret) use_cnt++; mutex_unlock(&state_lock); } if (!ret) dev_info(dev, "BW HWmon governor registered.\n"); else dev_err(dev, "BW HWmon governor registration failed!\n"); return ret; } MODULE_DESCRIPTION("HW monitor based dev DDR bandwidth voting driver"); MODULE_LICENSE("GPL v2"); drivers/devfreq/governor_bw_hwmon.h 0 → 100644 +74 −0 Original line number Diff line number Diff line /* * Copyright (c) 2014-2016, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #ifndef _GOVERNOR_BW_HWMON_H #define _GOVERNOR_BW_HWMON_H #include <linux/kernel.h> #include <linux/devfreq.h> /** * struct bw_hwmon - dev BW HW monitor info * @start_hwmon: Start the HW monitoring of the dev BW * @stop_hwmon: Stop the HW monitoring of dev BW * @is_valid_irq: Check whether the IRQ was triggered by the * counters used to monitor dev BW. * @meas_bw_and_set_irq: Return the measured bandwidth and set up the * IRQ to fire if the usage exceeds current * measurement by @tol percent. * @irq: IRQ number that corresponds to this HW * monitor. * @dev: Pointer to device that this HW monitor can * monitor. * @of_node: OF node of device that this HW monitor can * monitor. * @gov: devfreq_governor struct that should be used * when registering this HW monitor with devfreq. * Only the name field is expected to be * initialized. * @df: Devfreq node that this HW monitor is being * used for. NULL when not actively in use and * non-NULL when in use. * * One of dev, of_node or governor_name needs to be specified for a * successful registration. * */ struct bw_hwmon { int (*start_hwmon)(struct bw_hwmon *hw, unsigned long mbps); void (*stop_hwmon)(struct bw_hwmon *hw); unsigned long (*meas_bw_and_set_irq)(struct bw_hwmon *hw, unsigned int tol, unsigned int us); struct device *dev; struct device_node *of_node; struct devfreq_governor *gov; struct devfreq *df; }; #ifdef CONFIG_DEVFREQ_GOV_QCOM_BW_HWMON int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon); int update_bw_hwmon(struct bw_hwmon *hwmon); #else static inline int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon) { return 0; } int update_bw_hwmon(struct bw_hwmon *hwmon) { return 0; } #endif #endif /* _GOVERNOR_BW_HWMON_H */ Loading
drivers/devfreq/Kconfig +10 −0 Original line number Diff line number Diff line Loading @@ -80,6 +80,16 @@ config DEVFREQ_GOV_CPUFREQ CPU frequency to device frequency mapping table(s). This governor can be useful for controlling devices such as DDR, cache, CCI, etc. config DEVFREQ_GOV_QCOM_BW_HWMON tristate "HW monitor based governor for device BW" depends on QCOM_BIMC_BWMON help HW monitor based governor for device to DDR bandwidth voting. This governor sets the CPU BW vote by using BIMC counters to monitor the CPU's use of DDR. Since this uses target specific counters it can conflict with existing profiling tools. This governor is unlikely to be useful for non-QCOM devices. config DEVFREQ_GOV_QCOM_CACHE_HWMON tristate "HW monitor based governor for cache frequency" help Loading
drivers/devfreq/Makefile +1 −0 Original line number Diff line number Diff line Loading @@ -8,6 +8,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o obj-$(CONFIG_DEVFREQ_GOV_CPUFREQ) += governor_cpufreq.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_ADRENO_TZ) += governor_msm_adreno_tz.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_GPUBW_MON) += governor_bw_vbif.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_BW_HWMON) += governor_bw_hwmon.o obj-$(CONFIG_DEVFREQ_GOV_QCOM_CACHE_HWMON) += governor_cache_hwmon.o # DEVFREQ Drivers Loading
drivers/devfreq/governor_bw_hwmon.c 0 → 100644 +440 −0 Original line number Diff line number Diff line /* * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) "bw-hwmon: " fmt #include <linux/kernel.h> #include <linux/sizes.h> #include <linux/module.h> #include <linux/init.h> #include <linux/io.h> #include <linux/delay.h> #include <linux/ktime.h> #include <linux/time.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/mutex.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/of.h> #include <linux/devfreq.h> #include <trace/events/power.h> #include "governor.h" #include "governor_bw_hwmon.h" struct hwmon_node { unsigned int tolerance_percent; unsigned int guard_band_mbps; unsigned int decay_rate; unsigned int io_percent; unsigned int bw_step; unsigned long prev_ab; unsigned long *dev_ab; ktime_t prev_ts; bool mon_started; struct list_head list; void *orig_data; struct bw_hwmon *hw; struct devfreq_governor *gov; struct attribute_group *attr_grp; }; static LIST_HEAD(hwmon_list); static DEFINE_MUTEX(list_lock); static int use_cnt; static DEFINE_MUTEX(state_lock); #define show_attr(name) \ static ssize_t show_##name(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct devfreq *df = to_devfreq(dev); \ struct hwmon_node *hw = df->data; \ return snprintf(buf, PAGE_SIZE, "%u\n", hw->name); \ } #define store_attr(name, _min, _max) \ static ssize_t store_##name(struct device *dev, \ struct device_attribute *attr, const char *buf, \ size_t count) \ { \ struct devfreq *df = to_devfreq(dev); \ struct hwmon_node *hw = df->data; \ int ret; \ unsigned int val; \ ret = sscanf(buf, "%u", &val); \ if (ret != 1) \ return -EINVAL; \ val = max(val, _min); \ val = min(val, _max); \ hw->name = val; \ return count; \ } #define gov_attr(__attr, min, max) \ show_attr(__attr) \ store_attr(__attr, min, max) \ static DEVICE_ATTR(__attr, 0644, show_##__attr, store_##__attr) #define MIN_MS 10U #define MAX_MS 500U static unsigned long measure_bw_and_set_irq(struct hwmon_node *node) { ktime_t ts; unsigned int us; unsigned long mbps; struct bw_hwmon *hw = node->hw; /* * Since we are stopping the counters, we don't want this short work * to be interrupted by other tasks and cause the measurements to be * wrong. Not blocking interrupts to avoid affecting interrupt * latency and since they should be short anyway because they run in * atomic context. */ preempt_disable(); ts = ktime_get(); us = ktime_to_us(ktime_sub(ts, node->prev_ts)); if (!us) us = 1; mbps = hw->meas_bw_and_set_irq(hw, node->tolerance_percent, us); node->prev_ts = ts; preempt_enable(); dev_dbg(hw->df->dev.parent, "BW MBps = %6lu, period = %u\n", mbps, us); trace_bw_hwmon_meas(dev_name(hw->df->dev.parent), mbps, us, 0); return mbps; } static void compute_bw(struct hwmon_node *node, int mbps, unsigned long *freq, unsigned long *ab) { int new_bw; mbps += node->guard_band_mbps; if (mbps > node->prev_ab) { new_bw = mbps; } else { new_bw = mbps * node->decay_rate + node->prev_ab * (100 - node->decay_rate); new_bw /= 100; } node->prev_ab = new_bw; if (ab) *ab = roundup(new_bw, node->bw_step); *freq = (new_bw * 100) / node->io_percent; trace_bw_hwmon_update(dev_name(node->hw->df->dev.parent), new_bw, *freq, 0, 0); } static struct hwmon_node *find_hwmon_node(struct devfreq *df) { struct hwmon_node *node, *found = NULL; mutex_lock(&list_lock); list_for_each_entry(node, &hwmon_list, list) if (node->hw->dev == df->dev.parent || node->hw->of_node == df->dev.parent->of_node || (!node->hw->dev && !node->hw->of_node && node->gov == df->governor)) { found = node; break; } mutex_unlock(&list_lock); return found; } #define TOO_SOON_US (1 * USEC_PER_MSEC) int update_bw_hwmon(struct bw_hwmon *hwmon) { struct devfreq *df; struct hwmon_node *node; ktime_t ts; unsigned int us; int ret; if (!hwmon) return -EINVAL; df = hwmon->df; if (!df) return -ENODEV; node = find_hwmon_node(df); if (!node) return -ENODEV; if (!node->mon_started) return -EBUSY; dev_dbg(df->dev.parent, "Got update request\n"); devfreq_monitor_stop(df); /* * Don't recalc bandwidth if the interrupt comes right after a * previous bandwidth calculation. This is done for two reasons: * * 1. Sampling the BW during a very short duration can result in a * very inaccurate measurement due to very short bursts. * 2. This can only happen if the limit was hit very close to the end * of the previous sample period. Which means the current BW * estimate is not very off and doesn't need to be readjusted. */ ts = ktime_get(); us = ktime_to_us(ktime_sub(ts, node->prev_ts)); if (us > TOO_SOON_US) { mutex_lock(&df->lock); ret = update_devfreq(df); if (ret) dev_err(df->dev.parent, "Unable to update freq on request!\n"); mutex_unlock(&df->lock); } devfreq_monitor_start(df); return 0; } static int start_monitoring(struct devfreq *df) { int ret = 0; unsigned long mbps; struct device *dev = df->dev.parent; struct hwmon_node *node; struct bw_hwmon *hw; struct devfreq_dev_status stat; node = find_hwmon_node(df); if (!node) { dev_err(dev, "Unable to find HW monitor!\n"); return -ENODEV; } hw = node->hw; stat.private_data = NULL; if (df->profile->get_dev_status) ret = df->profile->get_dev_status(df->dev.parent, &stat); if (ret || !stat.private_data) dev_warn(dev, "Device doesn't take AB votes!\n"); else node->dev_ab = stat.private_data; hw->df = df; node->orig_data = df->data; df->data = node; node->prev_ts = ktime_get(); node->prev_ab = 0; mbps = (df->previous_freq * node->io_percent) / 100; ret = hw->start_hwmon(hw, mbps); if (ret) { dev_err(dev, "Unable to start HW monitor!\n"); goto err_start; } devfreq_monitor_start(df); node->mon_started = true; ret = sysfs_create_group(&df->dev.kobj, node->attr_grp); if (ret) goto err_sysfs; return 0; err_sysfs: node->mon_started = false; devfreq_monitor_stop(df); hw->stop_hwmon(hw); err_start: df->data = node->orig_data; node->orig_data = NULL; hw->df = NULL; node->dev_ab = NULL; return ret; } static void stop_monitoring(struct devfreq *df) { struct hwmon_node *node = df->data; struct bw_hwmon *hw = node->hw; sysfs_remove_group(&df->dev.kobj, node->attr_grp); node->mon_started = false; devfreq_monitor_stop(df); hw->stop_hwmon(hw); df->data = node->orig_data; node->orig_data = NULL; hw->df = NULL; /* * Not all governors know about this additional extended device * configuration. To avoid leaving the extended configuration at a * stale state, set it to 0 and let the next governor take it from * there. */ if (node->dev_ab) *node->dev_ab = 0; node->dev_ab = NULL; } static int devfreq_bw_hwmon_get_freq(struct devfreq *df, unsigned long *freq) { unsigned long mbps; struct hwmon_node *node = df->data; mbps = measure_bw_and_set_irq(node); compute_bw(node, mbps, freq, node->dev_ab); return 0; } gov_attr(tolerance_percent, 0U, 30U); gov_attr(guard_band_mbps, 0U, 2000U); gov_attr(decay_rate, 0U, 100U); gov_attr(io_percent, 1U, 100U); gov_attr(bw_step, 50U, 1000U); static struct attribute *dev_attr[] = { &dev_attr_tolerance_percent.attr, &dev_attr_guard_band_mbps.attr, &dev_attr_decay_rate.attr, &dev_attr_io_percent.attr, &dev_attr_bw_step.attr, NULL, }; static struct attribute_group dev_attr_group = { .name = "bw_hwmon", .attrs = dev_attr, }; static int devfreq_bw_hwmon_ev_handler(struct devfreq *df, unsigned int event, void *data) { int ret; unsigned int sample_ms; switch (event) { case DEVFREQ_GOV_START: sample_ms = df->profile->polling_ms; sample_ms = max(MIN_MS, sample_ms); sample_ms = min(MAX_MS, sample_ms); df->profile->polling_ms = sample_ms; ret = start_monitoring(df); if (ret) return ret; dev_dbg(df->dev.parent, "Enabled dev BW HW monitor governor\n"); break; case DEVFREQ_GOV_STOP: stop_monitoring(df); dev_dbg(df->dev.parent, "Disabled dev BW HW monitor governor\n"); break; case DEVFREQ_GOV_INTERVAL: sample_ms = *(unsigned int *)data; sample_ms = max(MIN_MS, sample_ms); sample_ms = min(MAX_MS, sample_ms); devfreq_interval_update(df, &sample_ms); break; } return 0; } static struct devfreq_governor devfreq_gov_bw_hwmon = { .name = "bw_hwmon", .get_target_freq = devfreq_bw_hwmon_get_freq, .event_handler = devfreq_bw_hwmon_ev_handler, }; int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon) { int ret = 0; struct hwmon_node *node; struct attribute_group *attr_grp; if (!hwmon->gov && !hwmon->dev && !hwmon->of_node) return -EINVAL; node = devm_kzalloc(dev, sizeof(*node), GFP_KERNEL); if (!node) return -ENOMEM; if (hwmon->gov) { attr_grp = devm_kzalloc(dev, sizeof(*attr_grp), GFP_KERNEL); if (!attr_grp) return -ENOMEM; hwmon->gov->get_target_freq = devfreq_bw_hwmon_get_freq; hwmon->gov->event_handler = devfreq_bw_hwmon_ev_handler; attr_grp->name = hwmon->gov->name; attr_grp->attrs = dev_attr; node->gov = hwmon->gov; node->attr_grp = attr_grp; } else { node->gov = &devfreq_gov_bw_hwmon; node->attr_grp = &dev_attr_group; } node->tolerance_percent = 10; node->guard_band_mbps = 100; node->decay_rate = 90; node->io_percent = 16; node->bw_step = 190; node->hw = hwmon; mutex_lock(&list_lock); list_add_tail(&node->list, &hwmon_list); mutex_unlock(&list_lock); if (hwmon->gov) { ret = devfreq_add_governor(hwmon->gov); } else { mutex_lock(&state_lock); if (!use_cnt) ret = devfreq_add_governor(&devfreq_gov_bw_hwmon); if (!ret) use_cnt++; mutex_unlock(&state_lock); } if (!ret) dev_info(dev, "BW HWmon governor registered.\n"); else dev_err(dev, "BW HWmon governor registration failed!\n"); return ret; } MODULE_DESCRIPTION("HW monitor based dev DDR bandwidth voting driver"); MODULE_LICENSE("GPL v2");
drivers/devfreq/governor_bw_hwmon.h 0 → 100644 +74 −0 Original line number Diff line number Diff line /* * Copyright (c) 2014-2016, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #ifndef _GOVERNOR_BW_HWMON_H #define _GOVERNOR_BW_HWMON_H #include <linux/kernel.h> #include <linux/devfreq.h> /** * struct bw_hwmon - dev BW HW monitor info * @start_hwmon: Start the HW monitoring of the dev BW * @stop_hwmon: Stop the HW monitoring of dev BW * @is_valid_irq: Check whether the IRQ was triggered by the * counters used to monitor dev BW. * @meas_bw_and_set_irq: Return the measured bandwidth and set up the * IRQ to fire if the usage exceeds current * measurement by @tol percent. * @irq: IRQ number that corresponds to this HW * monitor. * @dev: Pointer to device that this HW monitor can * monitor. * @of_node: OF node of device that this HW monitor can * monitor. * @gov: devfreq_governor struct that should be used * when registering this HW monitor with devfreq. * Only the name field is expected to be * initialized. * @df: Devfreq node that this HW monitor is being * used for. NULL when not actively in use and * non-NULL when in use. * * One of dev, of_node or governor_name needs to be specified for a * successful registration. * */ struct bw_hwmon { int (*start_hwmon)(struct bw_hwmon *hw, unsigned long mbps); void (*stop_hwmon)(struct bw_hwmon *hw); unsigned long (*meas_bw_and_set_irq)(struct bw_hwmon *hw, unsigned int tol, unsigned int us); struct device *dev; struct device_node *of_node; struct devfreq_governor *gov; struct devfreq *df; }; #ifdef CONFIG_DEVFREQ_GOV_QCOM_BW_HWMON int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon); int update_bw_hwmon(struct bw_hwmon *hwmon); #else static inline int register_bw_hwmon(struct device *dev, struct bw_hwmon *hwmon) { return 0; } int update_bw_hwmon(struct bw_hwmon *hwmon) { return 0; } #endif #endif /* _GOVERNOR_BW_HWMON_H */
