From df4d7b1451bf51e75406b6339e964d816f8e947e Mon Sep 17 00:00:00 2001 From: Matthias Kaehlcke Date: Wed, 18 Sep 2019 17:09:46 -0700 Subject: PM / devfreq: Make log message more explicit when devfreq device already exists Before creating a new devfreq device devfreq_add_device() checks if there is already a devfreq dev associated with the requesting device (parent). If that's the case the function rejects to create another devfreq dev for that parent and logs an error. The error message is very unspecific, make it a bit more explicit. Reviewed-by: Chanwoo Choi Signed-off-by: Matthias Kaehlcke Signed-off-by: MyungJoo Ham Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 446490c9d635..b905963cea7d 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -625,7 +625,7 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq = find_device_devfreq(dev); mutex_unlock(&devfreq_list_lock); if (!IS_ERR(devfreq)) { - dev_err(dev, "%s: Unable to create devfreq for the device.\n", + dev_err(dev, "%s: devfreq device already exists!\n", __func__); err = -EINVAL; goto err_out; -- cgit v1.2.3 From d68adc8f85cd757bd33c8d7b2660ad6f16f7f3dc Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Tue, 24 Sep 2019 10:26:53 +0300 Subject: PM / devfreq: Check NULL governor in available_governors_show The governor is initialized after sysfs attributes become visible so in theory the governor field can be NULL here. Fixes: bcf23c79c4e46 ("PM / devfreq: Fix available_governor sysfs") Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index b905963cea7d..60859a2400bc 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1195,7 +1195,7 @@ static ssize_t available_governors_show(struct device *d, * The devfreq with immutable governor (e.g., passive) shows * only own governor. */ - if (df->governor->immutable) { + if (df->governor && df->governor->immutable) { count = scnprintf(&buf[count], DEVFREQ_NAME_LEN, "%s ", df->governor_name); /* -- cgit v1.2.3 From 2abb0d5268ae7b5ddf82099b1f8d5aa8414637d4 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Tue, 24 Sep 2019 10:52:23 +0300 Subject: PM / devfreq: Lock devfreq in trans_stat_show There is no locking in this sysfs show function so stats printing can race with a devfreq_update_status called as part of freq switching or with initialization. Also add an assert in devfreq_update_status to make it clear that lock must be held by caller. Fixes: 39688ce6facd ("PM / devfreq: account suspend/resume for stats") Cc: stable@vger.kernel.org Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 60859a2400bc..d6c3dce9e9d5 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -160,6 +160,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) int lev, prev_lev, ret = 0; unsigned long cur_time; + lockdep_assert_held(&devfreq->lock); cur_time = jiffies; /* Immediately exit if previous_freq is not initialized yet. */ @@ -1397,12 +1398,17 @@ static ssize_t trans_stat_show(struct device *dev, int i, j; unsigned int max_state = devfreq->profile->max_state; - if (!devfreq->stop_polling && - devfreq_update_status(devfreq, devfreq->previous_freq)) - return 0; if (max_state == 0) return sprintf(buf, "Not Supported.\n"); + mutex_lock(&devfreq->lock); + if (!devfreq->stop_polling && + devfreq_update_status(devfreq, devfreq->previous_freq)) { + mutex_unlock(&devfreq->lock); + return 0; + } + mutex_unlock(&devfreq->lock); + len = sprintf(buf, " From : To\n"); len += sprintf(buf + len, " :"); for (i = 0; i < max_state; i++) -- cgit v1.2.3 From 5c0f6c79595760c9e366c3517314051af530e3e6 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 5 Nov 2019 00:56:14 +0300 Subject: PM / devfreq: Add new interrupt_driven flag for governors Currently interrupt-driven governors (like NVIDIA Tegra30 ACTMON governor) are used to set polling_ms=0 in order to avoid periodic polling of device status by devfreq core. This means that polling interval can't be changed by userspace for such governors. The new governor flag allows interrupt-driven governors to convey that devfreq core shouldn't perform polling of device status and thus generic devfreq polling interval could be supported by these governors now. Signed-off-by: Dmitry Osipenko Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 17 +++++++++++++++++ drivers/devfreq/governor.h | 3 +++ 2 files changed, 20 insertions(+) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index d6c3dce9e9d5..f840e61e5a27 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -410,6 +410,9 @@ static void devfreq_monitor(struct work_struct *work) */ void devfreq_monitor_start(struct devfreq *devfreq) { + if (devfreq->governor->interrupt_driven) + return; + INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); if (devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, @@ -427,6 +430,9 @@ EXPORT_SYMBOL(devfreq_monitor_start); */ void devfreq_monitor_stop(struct devfreq *devfreq) { + if (devfreq->governor->interrupt_driven) + return; + cancel_delayed_work_sync(&devfreq->work); } EXPORT_SYMBOL(devfreq_monitor_stop); @@ -454,6 +460,10 @@ void devfreq_monitor_suspend(struct devfreq *devfreq) devfreq_update_status(devfreq, devfreq->previous_freq); devfreq->stop_polling = true; mutex_unlock(&devfreq->lock); + + if (devfreq->governor->interrupt_driven) + return; + cancel_delayed_work_sync(&devfreq->work); } EXPORT_SYMBOL(devfreq_monitor_suspend); @@ -474,11 +484,15 @@ void devfreq_monitor_resume(struct devfreq *devfreq) if (!devfreq->stop_polling) goto out; + if (devfreq->governor->interrupt_driven) + goto out_update; + if (!delayed_work_pending(&devfreq->work) && devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); +out_update: devfreq->last_stat_updated = jiffies; devfreq->stop_polling = false; @@ -510,6 +524,9 @@ void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay) if (devfreq->stop_polling) goto out; + if (devfreq->governor->interrupt_driven) + goto out; + /* if new delay is zero, stop polling */ if (!new_delay) { mutex_unlock(&devfreq->lock); diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h index bbe5ff9fcecf..dc7533ccc3db 100644 --- a/drivers/devfreq/governor.h +++ b/drivers/devfreq/governor.h @@ -31,6 +31,8 @@ * @name: Governor's name * @immutable: Immutable flag for governor. If the value is 1, * this govenror is never changeable to other governor. + * @interrupt_driven: Devfreq core won't schedule polling work for this + * governor if value is set to 1. * @get_target_freq: Returns desired operating frequency for the device. * Basically, get_target_freq will run * devfreq_dev_profile.get_dev_status() to get the @@ -49,6 +51,7 @@ struct devfreq_governor { const char name[DEVFREQ_NAME_LEN]; const unsigned int immutable; + const unsigned int interrupt_driven; int (*get_target_freq)(struct devfreq *this, unsigned long *freq); int (*event_handler)(struct devfreq *devfreq, unsigned int event, void *data); -- cgit v1.2.3 From e1e047ace8cef6d143f38c7d769753f133becbe6 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Tue, 12 Nov 2019 11:47:34 +0100 Subject: PM / devfreq: Add missing locking while setting suspend_freq Commit 2abb0d5268ae ("PM / devfreq: Lock devfreq in trans_stat_show") revealed a missing locking while calling devfreq_update_status() function during suspend/resume cycle. Code analysis revealed that devfreq_set_target() function was called without needed locks held for setting device specific suspend_freq if such has been defined. This patch fixes that by adding the needed locking, what fixes following kernel warning on Exynos4412-based OdroidU3 board during system suspend: PM: suspend entry (deep) Filesystems sync: 0.002 seconds Freezing user space processes ... (elapsed 0.001 seconds) done. OOM killer disabled. Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1385 at drivers/devfreq/devfreq.c:204 devfreq_update_status+0xc0/0x188 Modules linked in: CPU: 2 PID: 1385 Comm: rtcwake Not tainted 5.4.0-rc6-next-20191111 #6848 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xb4/0xe0) [] (dump_stack) from [] (__warn+0xf4/0x10c) [] (__warn) from [] (warn_slowpath_fmt+0xb0/0xb8) [] (warn_slowpath_fmt) from [] (devfreq_update_status+0xc0/0x188) [] (devfreq_update_status) from [] (devfreq_set_target+0xb0/0x15c) [] (devfreq_set_target) from [] (devfreq_suspend+0x2c/0x64) [] (devfreq_suspend) from [] (dpm_suspend+0xa4/0x57c) [] (dpm_suspend) from [] (dpm_suspend_start+0x98/0xa0) [] (dpm_suspend_start) from [] (suspend_devices_and_enter+0xec/0xc74) [] (suspend_devices_and_enter) from [] (pm_suspend+0x340/0x410) [] (pm_suspend) from [] (state_store+0x6c/0xc8) [] (state_store) from [] (kernfs_fop_write+0x10c/0x228) [] (kernfs_fop_write) from [] (__vfs_write+0x30/0x1d0) [] (__vfs_write) from [] (vfs_write+0xa4/0x180) [] (vfs_write) from [] (ksys_write+0x60/0xd8) [] (ksys_write) from [] (ret_fast_syscall+0x0/0x28) Exception stack(0xed3d7fa8 to 0xed3d7ff0) ... irq event stamp: 9667 hardirqs last enabled at (9679): [] _raw_spin_unlock_irq+0x20/0x58 hardirqs last disabled at (9698): [] __schedule+0xd8/0x818 softirqs last enabled at (9694): [] __do_softirq+0x4fc/0x5fc softirqs last disabled at (9719): [] irq_exit+0x16c/0x170 ---[ end trace 41ac5b57d046bdbc ]--- ------------[ cut here ]------------ Signed-off-by: Marek Szyprowski Acked-by: Chanwoo Choi Signed-off-by: Rafael J. Wysocki --- drivers/devfreq/devfreq.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index f840e61e5a27..425149e8bab0 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -921,7 +921,9 @@ int devfreq_suspend_device(struct devfreq *devfreq) } if (devfreq->suspend_freq) { + mutex_lock(&devfreq->lock); ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0); + mutex_unlock(&devfreq->lock); if (ret) return ret; } @@ -949,7 +951,9 @@ int devfreq_resume_device(struct devfreq *devfreq) return 0; if (devfreq->resume_freq) { + mutex_lock(&devfreq->lock); ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0); + mutex_unlock(&devfreq->lock); if (ret) return ret; } -- cgit v1.2.3 From e876e710ede23f670494331e062d643928e4142a Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 31 Oct 2019 23:34:18 +0200 Subject: PM / devfreq: Fix devfreq_notifier_call returning errno Notifier callbacks shouldn't return negative errno but one of the NOTIFY_OK/DONE/BAD values. The OPP core will ignore return values from notifiers but returning a value that matches NOTIFY_STOP_MASK will stop the notification chain. Fix by always returning NOTIFY_OK. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 425149e8bab0..4de70bd0f63d 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -568,26 +568,28 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, void *devp) { struct devfreq *devfreq = container_of(nb, struct devfreq, nb); - int ret; + int err = -EINVAL; mutex_lock(&devfreq->lock); devfreq->scaling_min_freq = find_available_min_freq(devfreq); - if (!devfreq->scaling_min_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; - } + if (!devfreq->scaling_min_freq) + goto out; devfreq->scaling_max_freq = find_available_max_freq(devfreq); - if (!devfreq->scaling_max_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; - } + if (!devfreq->scaling_max_freq) + goto out; + + err = update_devfreq(devfreq); - ret = update_devfreq(devfreq); +out: mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from OPP notifier (%d)\n", + err); - return ret; + return NOTIFY_OK; } /** -- cgit v1.2.3 From e7cc792d00049c874010b398a27c3cc7bc8fef34 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 31 Oct 2019 23:34:19 +0200 Subject: PM / devfreq: Set scaling_max_freq to max on OPP notifier error The devfreq_notifier_call functions will update scaling_min_freq and scaling_max_freq when the OPP table is updated. If fetching the maximum frequency fails then scaling_max_freq remains set to zero which is confusing. Set to ULONG_MAX instead so we don't need special handling for this case in other places. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 4de70bd0f63d..66f0a795442b 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -577,8 +577,10 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, goto out; devfreq->scaling_max_freq = find_available_max_freq(devfreq); - if (!devfreq->scaling_max_freq) + if (!devfreq->scaling_max_freq) { + devfreq->scaling_max_freq = ULONG_MAX; goto out; + } err = update_devfreq(devfreq); -- cgit v1.2.3 From 46cecc0bf095bbffdf58618a1b4a5f9c9f073bf8 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 31 Oct 2019 23:34:26 +0200 Subject: PM / devfreq: Introduce get_freq_range helper Moving handling of min/max freq to a single function and call it from update_devfreq and for printing min/max freq values in sysfs. This changes the behavior of out-of-range min_freq/max_freq: clamping is now done at evaluation time. This means that if an out-of-range constraint is imposed by sysfs and it later becomes valid then it will be enforced. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 108 +++++++++++++++++++++++++--------------------- 1 file changed, 60 insertions(+), 48 deletions(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 66f0a795442b..65a4b6cf3fa5 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -98,6 +98,47 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) return max_freq; } +/** + * get_freq_range() - Get the current freq range + * @devfreq: the devfreq instance + * @min_freq: the min frequency + * @max_freq: the max frequency + * + * This takes into consideration all constraints. + */ +static void get_freq_range(struct devfreq *devfreq, + unsigned long *min_freq, + unsigned long *max_freq) +{ + unsigned long *freq_table = devfreq->profile->freq_table; + + lockdep_assert_held(&devfreq->lock); + + /* + * Initialize minimum/maximum frequency from freq table. + * The devfreq drivers can initialize this in either ascending or + * descending order and devfreq core supports both. + */ + if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { + *min_freq = freq_table[0]; + *max_freq = freq_table[devfreq->profile->max_state - 1]; + } else { + *min_freq = freq_table[devfreq->profile->max_state - 1]; + *max_freq = freq_table[0]; + } + + /* Apply constraints from sysfs */ + *min_freq = max(*min_freq, devfreq->min_freq); + *max_freq = min(*max_freq, devfreq->max_freq); + + /* Apply constraints from OPP interface */ + *min_freq = max(*min_freq, devfreq->scaling_min_freq); + *max_freq = min(*max_freq, devfreq->scaling_max_freq); + + if (*min_freq > *max_freq) + *min_freq = *max_freq; +} + /** * devfreq_get_freq_level() - Lookup freq_table for the frequency * @devfreq: the devfreq instance @@ -351,16 +392,7 @@ int update_devfreq(struct devfreq *devfreq) err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) return err; - - /* - * Adjust the frequency with user freq, QoS and available freq. - * - * List from the highest priority - * max_freq - * min_freq - */ - max_freq = min(devfreq->scaling_max_freq, devfreq->max_freq); - min_freq = max(devfreq->scaling_min_freq, devfreq->min_freq); + get_freq_range(devfreq, &min_freq, &max_freq); if (freq < min_freq) { freq = min_freq; @@ -1312,36 +1344,24 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, return -EINVAL; mutex_lock(&df->lock); - - if (value) { - if (value > df->max_freq) { - ret = -EINVAL; - goto unlock; - } - } else { - unsigned long *freq_table = df->profile->freq_table; - - /* Get minimum frequency according to sorting order */ - if (freq_table[0] < freq_table[df->profile->max_state - 1]) - value = freq_table[0]; - else - value = freq_table[df->profile->max_state - 1]; - } - df->min_freq = value; update_devfreq(df); - ret = count; -unlock: mutex_unlock(&df->lock); - return ret; + + return count; } static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct devfreq *df = to_devfreq(dev); + unsigned long min_freq, max_freq; + + mutex_lock(&df->lock); + get_freq_range(df, &min_freq, &max_freq); + mutex_unlock(&df->lock); - return sprintf(buf, "%lu\n", max(df->scaling_min_freq, df->min_freq)); + return sprintf(buf, "%lu\n", min_freq); } static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, @@ -1357,27 +1377,14 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, mutex_lock(&df->lock); - if (value) { - if (value < df->min_freq) { - ret = -EINVAL; - goto unlock; - } - } else { - unsigned long *freq_table = df->profile->freq_table; - - /* Get maximum frequency according to sorting order */ - if (freq_table[0] < freq_table[df->profile->max_state - 1]) - value = freq_table[df->profile->max_state - 1]; - else - value = freq_table[0]; - } + if (!value) + value = ULONG_MAX; df->max_freq = value; update_devfreq(df); - ret = count; -unlock: mutex_unlock(&df->lock); - return ret; + + return count; } static DEVICE_ATTR_RW(min_freq); @@ -1385,8 +1392,13 @@ static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct devfreq *df = to_devfreq(dev); + unsigned long min_freq, max_freq; + + mutex_lock(&df->lock); + get_freq_range(df, &min_freq, &max_freq); + mutex_unlock(&df->lock); - return sprintf(buf, "%lu\n", min(df->scaling_max_freq, df->max_freq)); + return sprintf(buf, "%lu\n", max_freq); } static DEVICE_ATTR_RW(max_freq); -- cgit v1.2.3 From 42a6b25e67df6ee6675e8d1eaf18065bd73328ba Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 14 Nov 2019 01:21:31 +0200 Subject: PM / devfreq: Don't fail devfreq_dev_release if not in list Right now devfreq_dev_release will print a warning and abort the rest of the cleanup if the devfreq instance is not part of the global devfreq_list. But this is a valid scenario, for example it can happen if the governor can't be found or on any other init error that happens after device_register. Initialize devfreq->node to an empty list head in devfreq_add_device so that list_del becomes a safe noop inside devfreq_dev_release and we can continue the rest of the cleanup. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 65a4b6cf3fa5..59f9fa8b54d1 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -637,11 +637,6 @@ static void devfreq_dev_release(struct device *dev) struct devfreq *devfreq = to_devfreq(dev); mutex_lock(&devfreq_list_lock); - if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { - mutex_unlock(&devfreq_list_lock); - dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); - return; - } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); @@ -696,6 +691,7 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; + INIT_LIST_HEAD(&devfreq->node); devfreq->profile = profile; strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; -- cgit v1.2.3 From 05d7ae15cfb18f9ce55eef85bb6bcd62d31acc57 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 5 Dec 2019 12:05:06 +0200 Subject: PM / devfreq: Add PM QoS support Register notifiers with the PM QoS framework in order to respond to requests for DEV_PM_QOS_MIN_FREQUENCY and DEV_PM_QOS_MAX_FREQUENCY. No notifiers are added by this patch but PM QoS constraints can be imposed externally (for example from other devices). Signed-off-by: Leonard Crestez Acked-by: Chanwoo Choi Reviewed-by: Matthias Kaehlcke Tested-by: Matthias Kaehlcke Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/devfreq.h | 5 +++ 2 files changed, 82 insertions(+) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 59f9fa8b54d1..f6e272085448 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -24,11 +24,14 @@ #include #include #include +#include #include "governor.h" #define CREATE_TRACE_POINTS #include +#define HZ_PER_KHZ 1000 + static struct class *devfreq_class; /* @@ -111,6 +114,7 @@ static void get_freq_range(struct devfreq *devfreq, unsigned long *max_freq) { unsigned long *freq_table = devfreq->profile->freq_table; + s32 qos_min_freq, qos_max_freq; lockdep_assert_held(&devfreq->lock); @@ -127,6 +131,16 @@ static void get_freq_range(struct devfreq *devfreq, *max_freq = freq_table[0]; } + /* Apply constraints from PM QoS */ + qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MIN_FREQUENCY); + qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MAX_FREQUENCY); + *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); + if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) + *max_freq = min(*max_freq, + (unsigned long)HZ_PER_KHZ * qos_max_freq); + /* Apply constraints from sysfs */ *min_freq = max(*min_freq, devfreq->min_freq); *max_freq = min(*max_freq, devfreq->max_freq); @@ -626,6 +640,45 @@ out: return NOTIFY_OK; } +/** + * qos_notifier_call() - Common handler for QoS constraints. + * @devfreq: the devfreq instance. + */ +static int qos_notifier_call(struct devfreq *devfreq) +{ + int err; + + mutex_lock(&devfreq->lock); + err = update_devfreq(devfreq); + mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from PM QoS (%d)\n", + err); + + return NOTIFY_OK; +} + +/** + * qos_min_notifier_call() - Callback for QoS min_freq changes. + * @nb: Should be devfreq->nb_min + */ +static int qos_min_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); +} + +/** + * qos_max_notifier_call() - Callback for QoS max_freq changes. + * @nb: Should be devfreq->nb_max + */ +static int qos_max_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); +} + /** * devfreq_dev_release() - Callback for struct device to release the device. * @dev: the devfreq device @@ -635,11 +688,23 @@ out: static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); + int err; mutex_lock(&devfreq_list_lock); list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove max_freq notifier: %d\n", err); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove min_freq notifier: %d\n", err); + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); @@ -762,6 +827,18 @@ struct devfreq *devfreq_add_device(struct device *dev, mutex_unlock(&devfreq->lock); + devfreq->nb_min.notifier_call = qos_min_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err) + goto err_devfreq; + + devfreq->nb_max.notifier_call = qos_max_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err) + goto err_devfreq; + mutex_lock(&devfreq_list_lock); governor = try_then_request_governor(devfreq->governor_name); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 2bae9ed3c783..8b92ccbd1962 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -136,6 +136,8 @@ struct devfreq_dev_profile { * @time_in_state: Statistics of devfreq states * @last_stat_updated: The last time stat updated * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier + * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY + * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY * * This structure stores the devfreq information for a give device. * @@ -178,6 +180,9 @@ struct devfreq { unsigned long last_stat_updated; struct srcu_notifier_head transition_notifier_list; + + struct notifier_block nb_min; + struct notifier_block nb_max; }; struct devfreq_freqs { -- cgit v1.2.3 From 27dbc542f651ed09de910f274b32634904103774 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Thu, 5 Dec 2019 12:05:07 +0200 Subject: PM / devfreq: Use PM QoS for sysfs min/max_freq Switch the handling of min_freq and max_freq from sysfs to use the dev_pm_qos_request interface. Since PM QoS handles frequencies as kHz this change reduces the precision of min_freq and max_freq. This shouldn't introduce problems because frequencies which are not an integer number of kHz are likely not an integer number of Hz either. Try to ensure compatibility by rounding min values down and rounding max values up. Signed-off-by: Leonard Crestez Acked-by: Chanwoo Choi Reviewed-by: Matthias Kaehlcke Tested-by: Matthias Kaehlcke [cw00.choi: Return -EAGAIN instead of -EINVAL if dev_pm_qos is inactive] Signed-off-by: Chanwoo Choi --- drivers/devfreq/devfreq.c | 76 ++++++++++++++++++++++++++++++++++++----------- include/linux/devfreq.h | 9 +++--- 2 files changed, 64 insertions(+), 21 deletions(-) (limited to 'drivers/devfreq/devfreq.c') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index f6e272085448..57f6944d65a6 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -141,10 +141,6 @@ static void get_freq_range(struct devfreq *devfreq, *max_freq = min(*max_freq, (unsigned long)HZ_PER_KHZ * qos_max_freq); - /* Apply constraints from sysfs */ - *min_freq = max(*min_freq, devfreq->min_freq); - *max_freq = min(*max_freq, devfreq->max_freq); - /* Apply constraints from OPP interface */ *min_freq = max(*min_freq, devfreq->scaling_min_freq); *max_freq = min(*max_freq, devfreq->scaling_max_freq); @@ -705,6 +701,19 @@ static void devfreq_dev_release(struct device *dev) dev_warn(dev->parent, "Failed to remove min_freq notifier: %d\n", err); + if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove max_freq request: %d\n", err); + } + if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove min_freq request: %d\n", err); + } + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); @@ -778,7 +787,6 @@ struct devfreq *devfreq_add_device(struct device *dev, err = -EINVAL; goto err_dev; } - devfreq->min_freq = devfreq->scaling_min_freq; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { @@ -786,7 +794,6 @@ struct devfreq *devfreq_add_device(struct device *dev, err = -EINVAL; goto err_dev; } - devfreq->max_freq = devfreq->scaling_max_freq; devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); atomic_set(&devfreq->suspend_count, 0); @@ -827,6 +834,16 @@ struct devfreq *devfreq_add_device(struct device *dev, mutex_unlock(&devfreq->lock); + err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, + DEV_PM_QOS_MIN_FREQUENCY, 0); + if (err < 0) + goto err_devfreq; + err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, + DEV_PM_QOS_MAX_FREQUENCY, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); + if (err < 0) + goto err_devfreq; + devfreq->nb_min.notifier_call = qos_min_notifier_call; err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, DEV_PM_QOS_MIN_FREQUENCY); @@ -1412,14 +1429,22 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_min_freq_req)) + return -EAGAIN; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - df->min_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + /* Round down to kHz for PM QoS */ + ret = dev_pm_qos_update_request(&df->user_min_freq_req, + value / HZ_PER_KHZ); + if (ret < 0) + return ret; return count; } @@ -1444,18 +1469,35 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_max_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - - if (!value) - value = ULONG_MAX; + /* + * PM QoS frequencies are in kHz so we need to convert. Convert by + * rounding upwards so that the acceptable interval never shrinks. + * + * For example if the user writes "666666666" to sysfs this value will + * be converted to 666667 kHz and back to 666667000 Hz before an OPP + * lookup, this ensures that an OPP of 666666666Hz is still accepted. + * + * A value of zero means "no limit". + */ + if (value) + value = DIV_ROUND_UP(value, HZ_PER_KHZ); + else + value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; - df->max_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); + if (ret < 0) + return ret; return count; } diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 8b92ccbd1962..fb376b5b7281 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -13,6 +13,7 @@ #include #include #include +#include #define DEVFREQ_NAME_LEN 16 @@ -123,8 +124,8 @@ struct devfreq_dev_profile { * @previous_freq: previously configured frequency value. * @data: Private data of the governor. The devfreq framework does not * touch this. - * @min_freq: Limit minimum frequency requested by user (0: none) - * @max_freq: Limit maximum frequency requested by user (0: none) + * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) + * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. @@ -163,8 +164,8 @@ struct devfreq { void *data; /* private data for governors */ - unsigned long min_freq; - unsigned long max_freq; + struct dev_pm_qos_request user_min_freq_req; + struct dev_pm_qos_request user_max_freq_req; unsigned long scaling_min_freq; unsigned long scaling_max_freq; bool stop_polling; -- cgit v1.2.3