From 18a387099b3e3fd901cc706f708b163aa45347b6 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 25 Jan 2013 21:51:32 +0100 Subject: [PATCH] ACPI / PM: Expose lists of device power resources to user space Since ACPI power resources are going to be used more extensively on new hardware platforms, it is necessary to allow user space (powertop in particular) to look at the lists of power resources corresponding to different power states of devices for diagnostics and control purposes. For this reason, for each power state of an ACPI device node using power resources create a special attribute group under the device node's directory in sysfs containing links to sysfs directories representing the power resources in that list. The names of the new attribute groups are "power_resources_", where is the state name i.e. "D0", "D1", "D2", or "D3hot". Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- .../testing/sysfs-devices-power_resources_D0 | 13 +++ .../testing/sysfs-devices-power_resources_D1 | 14 +++ .../testing/sysfs-devices-power_resources_D2 | 14 +++ .../sysfs-devices-power_resources_D3hot | 14 +++ drivers/acpi/power.c | 104 +++++++++++++++--- 5 files changed, 146 insertions(+), 13 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-devices-power_resources_D0 create mode 100644 Documentation/ABI/testing/sysfs-devices-power_resources_D1 create mode 100644 Documentation/ABI/testing/sysfs-devices-power_resources_D2 create mode 100644 Documentation/ABI/testing/sysfs-devices-power_resources_D3hot diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D0 b/Documentation/ABI/testing/sysfs-devices-power_resources_D0 new file mode 100644 index 000000000000..73b77a6be196 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D0 @@ -0,0 +1,13 @@ +What: /sys/devices/.../power_resources_D0/ +Date: January 2013 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power_resources_D0/ directory is only + present for device objects representing ACPI device nodes that + use ACPI power resources for power management. + + If present, it contains symbolic links to device directories + representing ACPI power resources that need to be turned on for + the given device node to be in ACPI power state D0. The names + of the links are the same as the names of the directories they + point to. diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D1 b/Documentation/ABI/testing/sysfs-devices-power_resources_D1 new file mode 100644 index 000000000000..30c20703fb8c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D1 @@ -0,0 +1,14 @@ +What: /sys/devices/.../power_resources_D1/ +Date: January 2013 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power_resources_D1/ directory is only + present for device objects representing ACPI device nodes that + use ACPI power resources for power management and support ACPI + power state D1. + + If present, it contains symbolic links to device directories + representing ACPI power resources that need to be turned on for + the given device node to be in ACPI power state D1. The names + of the links are the same as the names of the directories they + point to. diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D2 b/Documentation/ABI/testing/sysfs-devices-power_resources_D2 new file mode 100644 index 000000000000..fd9d84b421e1 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D2 @@ -0,0 +1,14 @@ +What: /sys/devices/.../power_resources_D2/ +Date: January 2013 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power_resources_D2/ directory is only + present for device objects representing ACPI device nodes that + use ACPI power resources for power management and support ACPI + power state D2. + + If present, it contains symbolic links to device directories + representing ACPI power resources that need to be turned on for + the given device node to be in ACPI power state D2. The names + of the links are the same as the names of the directories they + point to. diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot b/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot new file mode 100644 index 000000000000..3df32c20addf --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot @@ -0,0 +1,14 @@ +What: /sys/devices/.../power_resources_D3hot/ +Date: January 2013 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power_resources_D3hot/ directory is only + present for device objects representing ACPI device nodes that + use ACPI power resources for power management and support ACPI + power state D3hot. + + If present, it contains symbolic links to device directories + representing ACPI power resources that need to be turned on for + the given device node to be in ACPI power state D3hot. The + names of the links are the same as the names of the directories + they point to. diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 946720a4db57..9466f56b938f 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include "sleep.h" @@ -417,24 +418,101 @@ static void acpi_power_remove_dependent(struct acpi_power_resource *resource, } } -void acpi_power_add_remove_device(struct acpi_device *adev, bool add) +static struct attribute *attrs[] = { + NULL, +}; + +static struct attribute_group attr_groups[] = { + [ACPI_STATE_D0] = { + .name = "power_resources_D0", + .attrs = attrs, + }, + [ACPI_STATE_D1] = { + .name = "power_resources_D1", + .attrs = attrs, + }, + [ACPI_STATE_D2] = { + .name = "power_resources_D2", + .attrs = attrs, + }, + [ACPI_STATE_D3_HOT] = { + .name = "power_resources_D3hot", + .attrs = attrs, + }, +}; + +static void acpi_power_hide_list(struct acpi_device *adev, int state) +{ + struct acpi_device_power_state *ps = &adev->power.states[state]; + struct acpi_power_resource_entry *entry; + + if (list_empty(&ps->resources)) + return; + + list_for_each_entry_reverse(entry, &ps->resources, node) { + struct acpi_device *res_dev = &entry->resource->device; + + sysfs_remove_link_from_group(&adev->dev.kobj, + attr_groups[state].name, + dev_name(&res_dev->dev)); + } + sysfs_remove_group(&adev->dev.kobj, &attr_groups[state]); +} + +static void acpi_power_expose_list(struct acpi_device *adev, int state) { - if (adev->power.flags.power_resources) { - struct acpi_device_power_state *ps; - struct acpi_power_resource_entry *entry; - - ps = &adev->power.states[ACPI_STATE_D0]; - list_for_each_entry(entry, &ps->resources, node) { - struct acpi_power_resource *resource = entry->resource; - - if (add) - acpi_power_add_dependent(resource, adev); - else - acpi_power_remove_dependent(resource, adev); + struct acpi_device_power_state *ps = &adev->power.states[state]; + struct acpi_power_resource_entry *entry; + int ret; + + if (list_empty(&ps->resources)) + return; + + ret = sysfs_create_group(&adev->dev.kobj, &attr_groups[state]); + if (ret) + return; + + list_for_each_entry(entry, &ps->resources, node) { + struct acpi_device *res_dev = &entry->resource->device; + + ret = sysfs_add_link_to_group(&adev->dev.kobj, + attr_groups[state].name, + &res_dev->dev.kobj, + dev_name(&res_dev->dev)); + if (ret) { + acpi_power_hide_list(adev, state); + break; } } } +void acpi_power_add_remove_device(struct acpi_device *adev, bool add) +{ + struct acpi_device_power_state *ps; + struct acpi_power_resource_entry *entry; + int state; + + if (!adev->power.flags.power_resources) + return; + + ps = &adev->power.states[ACPI_STATE_D0]; + list_for_each_entry(entry, &ps->resources, node) { + struct acpi_power_resource *resource = entry->resource; + + if (add) + acpi_power_add_dependent(resource, adev); + else + acpi_power_remove_dependent(resource, adev); + } + + for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++) { + if (add) + acpi_power_expose_list(adev, state); + else + acpi_power_hide_list(adev, state); + } +} + int acpi_power_min_system_level(struct list_head *list) { struct acpi_power_resource_entry *entry; -- 2.20.1