lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1433170082-117462-2-git-send-email-andriy.shevchenko@linux.intel.com>
Date:	Mon,  1 Jun 2015 17:47:55 +0300
From:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	linux-acpi@...r.kernel.org, linux-pm@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Vinod Koul <vinod.koul@...el.com>,
	Lee Jones <lee.jones@...aro.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	linux-kernel@...r.kernel.org, dmaengine@...r.kernel.org,
	Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
	Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
	"Wysocki, Rafael J" <rafael.j.wysocki@...el.com>,
	Mike Turquette <mturquette@...aro.org>
Cc:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v3 1/8] PM / QoS: Make it possible to expose device latency tolerance to userspace

From: Mika Westerberg <mika.westerberg@...ux.intel.com>

Typically when a device is created the bus core it belongs to (for example
PCI) does not know if the device supports things like latency tolerance.
This is left to the driver that binds to the device in question. However,
at that time the device has already been created and there is no way to set
its dev->power.set_latency_tolerance anymore.

So follow what has been done for other PM QoS attributes as well and allow
drivers to expose and hide latency tolerance from userspace, if the device
supports it.

Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/base/power/power.h |  2 ++
 drivers/base/power/qos.c   | 37 +++++++++++++++++++++++++++++++++++++
 drivers/base/power/sysfs.c | 11 +++++++++++
 include/linux/pm_qos.h     |  5 +++++
 4 files changed, 55 insertions(+)

diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index b6b8a27..0e62fb2 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -33,6 +33,8 @@ extern int pm_qos_sysfs_add_resume_latency(struct device *dev);
 extern void pm_qos_sysfs_remove_resume_latency(struct device *dev);
 extern int pm_qos_sysfs_add_flags(struct device *dev);
 extern void pm_qos_sysfs_remove_flags(struct device *dev);
+extern int pm_qos_sysfs_add_latency_tolerance(struct device *dev);
+extern void pm_qos_sysfs_remove_latency_tolerance(struct device *dev);
 
 #else /* CONFIG_PM */
 
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index e56d538..7f3646e 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -883,3 +883,40 @@ int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
+
+/**
+ * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace
+ * @dev: Device whose latency tolerance to expose
+ */
+int dev_pm_qos_expose_latency_tolerance(struct device *dev)
+{
+	int ret;
+
+	if (!dev->power.set_latency_tolerance)
+		return -EINVAL;
+
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+	ret = pm_qos_sysfs_add_latency_tolerance(dev);
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance);
+
+/**
+ * dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace
+ * @dev: Device whose latency tolerance to hide
+ */
+void dev_pm_qos_hide_latency_tolerance(struct device *dev)
+{
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+	pm_qos_sysfs_remove_latency_tolerance(dev);
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
+
+	/* Remove the request from user space now */
+	pm_runtime_get_sync(dev);
+	dev_pm_qos_update_user_latency_tolerance(dev,
+		PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT);
+	pm_runtime_put(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index d2be3f9..a7b4679 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -738,6 +738,17 @@ void pm_qos_sysfs_remove_flags(struct device *dev)
 	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
+int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
+{
+	return sysfs_merge_group(&dev->kobj,
+				 &pm_qos_latency_tolerance_attr_group);
+}
+
+void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
+{
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
+}
+
 void rpm_sysfs_remove(struct device *dev)
 {
 	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 7b3ae0c..0f65d36 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -161,6 +161,8 @@ void dev_pm_qos_hide_flags(struct device *dev);
 int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
 s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev);
 int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val);
+int dev_pm_qos_expose_latency_tolerance(struct device *dev);
+void dev_pm_qos_hide_latency_tolerance(struct device *dev);
 
 static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 {
@@ -229,6 +231,9 @@ static inline s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
 			{ return PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; }
 static inline int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 			{ return 0; }
+static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev)
+			{ return 0; }
+static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
 
 static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev) { return 0; }
 static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ