diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform_profile | 24 | ||||
| -rw-r--r-- | Documentation/userspace-api/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/userspace-api/sysfs-platform_profile.rst | 42 | ||||
| -rw-r--r-- | drivers/acpi/Kconfig | 17 | ||||
| -rw-r--r-- | drivers/acpi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/acpi/platform_profile.c | 177 | ||||
| -rw-r--r-- | include/linux/platform_profile.h | 41 |
7 files changed, 303 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-platform_profile b/Documentation/ABI/testing/sysfs-platform_profile new file mode 100644 index 000000000000..9d6b89b66cca --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform_profile @@ -0,0 +1,24 @@ +What: /sys/firmware/acpi/platform_profile_choices +Date: October 2020 +Contact: Hans de Goede <hdegoede@redhat.com> +Description: This file contains a space-separated list of profiles supported for this device. + + Drivers must use the following standard profile-names: + + ============ ============================================ + low-power Low power consumption + cool Cooler operation + quiet Quieter operation + balanced Balance between low power consumption and performance + performance High performance operation + ============ ============================================ + + Userspace may expect drivers to offer more than one of these + standard profile names. + +What: /sys/firmware/acpi/platform_profile +Date: October 2020 +Contact: Hans de Goede <hdegoede@redhat.com> +Description: Reading this file gives the current selected profile for this + device. Writing this file with one of the strings from + platform_profile_choices changes the profile to the new value. diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst index acd2cc2a538d..d29b020e5622 100644 --- a/Documentation/userspace-api/index.rst +++ b/Documentation/userspace-api/index.rst @@ -24,6 +24,7 @@ place where this information is gathered. ioctl/index iommu media/index + sysfs-platform_profile .. only:: subproject and html diff --git a/Documentation/userspace-api/sysfs-platform_profile.rst b/Documentation/userspace-api/sysfs-platform_profile.rst new file mode 100644 index 000000000000..c33a71263d9e --- /dev/null +++ b/Documentation/userspace-api/sysfs-platform_profile.rst @@ -0,0 +1,42 @@ +===================================================================== +Platform Profile Selection (e.g. /sys/firmware/acpi/platform_profile) +===================================================================== + +On modern systems the platform performance, temperature, fan and other +hardware related characteristics are often dynamically configurable. The +platform configuration is often automatically adjusted to the current +conditions by some automatic mechanism (which may very well live outside +the kernel). + +These auto platform adjustment mechanisms often can be configured with +one of several platform profiles, with either a bias towards low power +operation or towards performance. + +The purpose of the platform_profile attribute is to offer a generic sysfs +API for selecting the platform profile of these automatic mechanisms. + +Note that this API is only for selecting the platform profile, it is +NOT a goal of this API to allow monitoring the resulting performance +characteristics. Monitoring performance is best done with device/vendor +specific tools such as e.g. turbostat. + +Specifically when selecting a high performance profile the actual achieved +performance may be limited by various factors such as: the heat generated +by other components, room temperature, free air flow at the bottom of a +laptop, etc. It is explicitly NOT a goal of this API to let userspace know +about any sub-optimal conditions which are impeding reaching the requested +performance level. + +Since numbers on their own cannot represent the multiple variables that a +profile will adjust (power consumption, heat generation, etc) this API +uses strings to describe the various profiles. To make sure that userspace +gets a consistent experience the sysfs-platform_profile ABI document defines +a fixed set of profile names. Drivers *must* map their internal profile +representation onto this fixed set. + +If there is no good match when mapping then a new profile name may be +added. Drivers which wish to introduce new profile names must: + + 1. Explain why the existing profile names canot be used. + 2. Add the new profile name, along with a clear description of the + expected behaviour, to the sysfs-platform_profile ABI documentation. diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index edf1558c1105..5ddff93e38c2 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -326,6 +326,23 @@ config ACPI_THERMAL To compile this driver as a module, choose M here: the module will be called thermal. +config ACPI_PLATFORM_PROFILE + tristate "ACPI Platform Profile Driver" + default m + help + This driver adds support for platform-profiles on platforms that + support it. + + Platform-profiles can be used to control the platform behaviour. For + example whether to operate in a lower power mode, in a higher + power performance mode or between the two. + + This driver provides the sysfs interface and is used as the registration + point for platform specific drivers. + + Which profiles are supported is determined on a per-platform basis and + should be obtained from the platform specific driver. + config ACPI_CUSTOM_DSDT_FILE string "Custom DSDT Table file to include" default "" diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 076894a3330f..52b627c7f977 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -79,6 +79,7 @@ obj-$(CONFIG_ACPI_PCI_SLOT) += pci_slot.o obj-$(CONFIG_ACPI_PROCESSOR) += processor.o obj-$(CONFIG_ACPI) += container.o obj-$(CONFIG_ACPI_THERMAL) += thermal.o +obj-$(CONFIG_ACPI_PLATFORM_PROFILE) += platform_profile.o obj-$(CONFIG_ACPI_NFIT) += nfit/ obj-$(CONFIG_ACPI_NUMA) += numa/ obj-$(CONFIG_ACPI) += acpi_memhotplug.o diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c new file mode 100644 index 000000000000..4a59c5993bde --- /dev/null +++ b/drivers/acpi/platform_profile.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +/* Platform profile sysfs interface */ + +#include <linux/acpi.h> +#include <linux/bits.h> +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/platform_profile.h> +#include <linux/sysfs.h> + +static struct platform_profile_handler *cur_profile; +static DEFINE_MUTEX(profile_lock); + +static const char * const profile_names[] = { + [PLATFORM_PROFILE_LOW_POWER] = "low-power", + [PLATFORM_PROFILE_COOL] = "cool", + [PLATFORM_PROFILE_QUIET] = "quiet", + [PLATFORM_PROFILE_BALANCED] = "balanced", + [PLATFORM_PROFILE_PERFORMANCE] = "performance", +}; +static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST); + +static ssize_t platform_profile_choices_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int len = 0; + int err, i; + + err = mutex_lock_interruptible(&profile_lock); + if (err) + return err; + + if (!cur_profile) { + mutex_unlock(&profile_lock); + return -ENODEV; + } + + for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) { + if (len == 0) + len += sysfs_emit_at(buf, len, "%s", profile_names[i]); + else + len += sysfs_emit_at(buf, len, " %s", profile_names[i]); + } + len += sysfs_emit_at(buf, len, "\n"); + mutex_unlock(&profile_lock); + return len; +} + +static ssize_t platform_profile_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED; + int err; + + err = mutex_lock_interruptible(&profile_lock); + if (err) + return err; + + if (!cur_profile) { + mutex_unlock(&profile_lock); + return -ENODEV; + } + + err = cur_profile->profile_get(cur_profile, &profile); + mutex_unlock(&profile_lock); + if (err) + return err; + + /* Check that profile is valid index */ + if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names)))) + return -EIO; + + return sysfs_emit(buf, "%s\n", profile_names[profile]); +} + +static ssize_t platform_profile_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int err, i; + + err = mutex_lock_interruptible(&profile_lock); + if (err) + return err; + + if (!cur_profile) { + mutex_unlock(&profile_lock); + return -ENODEV; + } + + /* Scan for a matching profile */ + i = sysfs_match_string(profile_names, buf); + if (i < 0) { + mutex_unlock(&profile_lock); + return -EINVAL; + } + + /* Check that platform supports this profile choice */ + if (!test_bit(i, cur_profile->choices)) { + mutex_unlock(&profile_lock); + return -EOPNOTSUPP; + } + + err = cur_profile->profile_set(cur_profile, i); + mutex_unlock(&profile_lock); + if (err) + return err; + return count; +} + +static DEVICE_ATTR_RO(platform_profile_choices); +static DEVICE_ATTR_RW(platform_profile); + +static struct attribute *platform_profile_attrs[] = { + &dev_attr_platform_profile_choices.attr, + &dev_attr_platform_profile.attr, + NULL +}; + +static const struct attribute_group platform_profile_group = { + .attrs = platform_profile_attrs +}; + +void platform_profile_notify(void) +{ + if (!cur_profile) + return; + sysfs_notify(acpi_kobj, NULL, "platform_profile"); +} +EXPORT_SYMBOL_GPL(platform_profile_notify); + +int platform_profile_register(struct platform_profile_handler *pprof) +{ + int err; + + mutex_lock(&profile_lock); + /* We can only have one active profile */ + if (cur_profile) { + mutex_unlock(&profile_lock); + return -EEXIST; + } + + /* Sanity check the profile handler field are set */ + if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) || + !pprof->profile_set || !pprof->profile_get) { + mutex_unlock(&profile_lock); + return -EINVAL; + } + + err = sysfs_create_group(acpi_kobj, &platform_profile_group); + if (err) { + mutex_unlock(&profile_lock); + return err; + } + + cur_profile = pprof; + mutex_unlock(&profile_lock); + return 0; +} +EXPORT_SYMBOL_GPL(platform_profile_register); + +int platform_profile_remove(void) +{ + sysfs_remove_group(acpi_kobj, &platform_profile_group); + + mutex_lock(&profile_lock); + cur_profile = NULL; + mutex_unlock(&profile_lock); + return 0; +} +EXPORT_SYMBOL_GPL(platform_profile_remove); + +MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h new file mode 100644 index 000000000000..a26542d53058 --- /dev/null +++ b/include/linux/platform_profile.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Platform profile sysfs interface + * + * See Documentation/ABI/testing/sysfs-platform_profile.rst for more + * information. + */ + +#ifndef _PLATFORM_PROFILE_H_ +#define _PLATFORM_PROFILE_H_ + +#include <linux/bitops.h> + +/* + * If more options are added please update profile_names + * array in platform-profile.c and sysfs-platform-profile.rst + * documentation. + */ + +enum platform_profile_option { + PLATFORM_PROFILE_LOW_POWER, + PLATFORM_PROFILE_COOL, + PLATFORM_PROFILE_QUIET, + PLATFORM_PROFILE_BALANCED, + PLATFORM_PROFILE_PERFORMANCE, + PLATFORM_PROFILE_LAST, /*must always be last */ +}; + +struct platform_profile_handler { + unsigned long choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)]; + int (*profile_get)(struct platform_profile_handler *pprof, + enum platform_profile_option *profile); + int (*profile_set)(struct platform_profile_handler *pprof, + enum platform_profile_option profile); +}; + +int platform_profile_register(struct platform_profile_handler *pprof); +int platform_profile_remove(void); +void platform_profile_notify(void); + +#endif /*_PLATFORM_PROFILE_H_*/ |