cpuidle: move to use bus_get_dev_root()

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there

cpuidle: move to use bus_get_dev_root()

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

This allows us to clean up the cpuidle_add_interface() call a bit as it
was only called in one place, with the same argument so just put that
into the function itself. Note that cpuidle_remove_interface() should
also probably be removed in the future as there are no callers of it for
some reason.

Cc: Daniel Lezcano <[email protected]>
Cc: [email protected]
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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cpuidle: sysfs: make kobj_type structures constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of

cpuidle: sysfs: make kobj_type structures constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: use default_groups in kobj_type

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the cpuidle s

cpuidle: use default_groups in kobj_type

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the cpuidle sysfs code to use default_groups field which
has been the preferred way since aa30f47cf666 ("kobject: Add support for
default attribute groups to kobj_type") so that we can soon get rid of
the obsolete default_attrs field.

Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Fix cpuidle_remove_state_sysfs() kerneldoc comment

Fix function name in sysfs.c kernel-doc comment
to remove a warning found by running scripts/kernel-doc,
which is caused by using 'make W=

cpuidle: Fix cpuidle_remove_state_sysfs() kerneldoc comment

Fix function name in sysfs.c kernel-doc comment
to remove a warning found by running scripts/kernel-doc,
which is caused by using 'make W=1'.

drivers/cpuidle/sysfs.c:512: warning: expecting prototype for
cpuidle_remove_driver_sysfs(). Prototype was for
cpuidle_remove_state_sysfs() instead

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Fix kobject memory leaks in error paths

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading

cpuidle: Fix kobject memory leaks in error paths

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading to memory leaks.

Fix those and also defer the initialization of dev->kobj_dev until
after the error check, so that we do not end up with a dangling
pointer.

Fixes: c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
Signed-off-by: Anel Orazgaliyeva <[email protected]>
Suggested-by: Aman Priyadarshi <[email protected]>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: record state entry rejection statistics

CPUs may fail to enter the chosen idle state if there was a
pending interrupt, causing the cpuidle driver to return an error
value.

Record that and

cpuidle: record state entry rejection statistics

CPUs may fail to enter the chosen idle state if there was a
pending interrupt, causing the cpuidle driver to return an error
value.

Record that and export it via sysfs along with the other idle state
statistics.

This could prove useful in understanding behavior of the governor
and the system during usecases that involve multiple CPUs.

Signed-off-by: Lina Iyer <[email protected]>
[ rjw: Changelog and documentation edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Fix three reference count leaks

kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory as

cpuidle: Fix three reference count leaks

kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object.

Previous commit "b8eb718348b8" fixed a similar problem.

Signed-off-by: Qiushi Wu <[email protected]>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: Remove sysfs_switch and switch attributes

Since the cpuidle governor can be switched via sysfs in default,
remove sysfs_switch and cpuidle_switch_attrs.

Signed-off-by: Hanjun Guo <g

cpuidle: sysfs: Remove sysfs_switch and switch attributes

Since the cpuidle governor can be switched via sysfs in default,
remove sysfs_switch and cpuidle_switch_attrs.

Signed-off-by: Hanjun Guo <[email protected]>
Reviewed-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Acked-by: Daniel Lezcano <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Make cpuidle governor switchable to be the default behaviour

For now cpuidle governor can be switched via sysfs only when the
boot option "cpuidle_sysfs_switch" is passed, but it's importan

cpuidle: Make cpuidle governor switchable to be the default behaviour

For now cpuidle governor can be switched via sysfs only when the
boot option "cpuidle_sysfs_switch" is passed, but it's important
to switch the governor to adapt to different workloads, especially
after TEO and haltpoll governor were introduced.

Add available_governors and current_governor into the default
attributes, but reserve the current_governor_ro for compatiblity.

Signed-off-by: Hanjun Guo <[email protected]>
Reviewed-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Acked-by: Daniel Lezcano <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: Accept governor name with 15 characters

CPUIDLE_NAME_LEN is 16, so it's possible to accept governor name
with 15 characters, but now store_current_governor() rejects
governor name wi

cpuidle: sysfs: Accept governor name with 15 characters

CPUIDLE_NAME_LEN is 16, so it's possible to accept governor name
with 15 characters, but now store_current_governor() rejects
governor name with 15 characters as it returns -EINVAL if count
equals CPUIDLE_NAME_LEN.

Refactor the code to accept such case and simplify the code.

Signed-off-by: Hanjun Guo <[email protected]>
Reviewed-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: Fix the overlap for showing available governors

When showing the available governors, it's "%s " in scnprintf(),
not "%s", so if the governor name has 15 characters, it will
overlap

cpuidle: sysfs: Fix the overlap for showing available governors

When showing the available governors, it's "%s " in scnprintf(),
not "%s", so if the governor name has 15 characters, it will
overlap with the later one, fix it by adding one more for the
size.

While we are at it, fix the minor coding style issue and remove
the "/sizeof(char)" since sizeof(char) always equals 1.

Signed-off-by: Hanjun Guo <[email protected]>
Reviewed-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: Minor coding style corrections

Fix two minor coding style issues.

Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

cpuidle: sysfs: Remove the unused define_one_r(o/w) macros

The define_one_ro and define_one_rw macros are not used,
remove it.

Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael

cpuidle: sysfs: Remove the unused define_one_r(o/w) macros

The define_one_ro and define_one_rw macros are not used,
remove it.

Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: fix warnings when compiling with W=1

Fix kernel documentation comments to remove warnings when
compiling with W=1.

Signed-off-by: Benjamin Gaignard <[email protected]>
Signed

cpuidle: sysfs: fix warnings when compiling with W=1

Fix kernel documentation comments to remove warnings when
compiling with W=1.

Signed-off-by: Benjamin Gaignard <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Allow idle states to be disabled by default

In certain situations it may be useful to prevent some idle states
from being used by default while allowing user space to enable them
later on.

cpuidle: Allow idle states to be disabled by default

In certain situations it may be useful to prevent some idle states
from being used by default while allowing user space to enable them
later on.

For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to
mark idle states that should be disabled by default, make the core
set CPUIDLE_STATE_DISABLED_BY_USER for those states at the
initialization time and add a new state attribute in sysfs,
"default_status", to inform user space of the initial status of
the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it,
"enabled" otherwise).

Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Use nanoseconds as the unit of time

Currently, the cpuidle subsystem uses microseconds as the unit of
time which (among other things) causes the idle loop to incur some
integer division ove

cpuidle: Use nanoseconds as the unit of time

Currently, the cpuidle subsystem uses microseconds as the unit of
time which (among other things) causes the idle loop to incur some
integer division overhead for no clear benefit.

In order to allow cpuidle to measure time in nanoseconds, add two
new fields, exit_latency_ns and target_residency_ns, to represent the
exit latency and target residency of an idle state in nanoseconds,
respectively, to struct cpuidle_state and initialize them with the
help of the corresponding values in microseconds provided by drivers.
Additionally, change cpuidle_governor_latency_req() to return the
idle state exit latency constraint in nanoseconds.

Also meeasure idle state residency (last_residency_ns in struct
cpuidle_device and time_ns in struct cpuidle_driver) in nanoseconds
and update the cpuidle core and governors accordingly.

However, the menu governor still computes typical intervals in
microseconds to avoid integer overflows.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>

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cpuidle: Consolidate disabled state checks

There are two reasons why CPU idle states may be disabled: either
because the driver has disabled them or because they have been
disabled by user space via

cpuidle: Consolidate disabled state checks

There are two reasons why CPU idle states may be disabled: either
because the driver has disabled them or because they have been
disabled by user space via sysfs.

In the former case, the state's "disabled" flag is set once during
the initialization of the driver and it is never cleared later (it
is read-only effectively). In the latter case, the "disable" field
of the given state's cpuidle_state_usage struct is set and it may be
changed via sysfs. Thus checking whether or not an idle state has
been disabled involves reading these two flags every time.

In order to avoid the additional check of the state's "disabled" flag
(which is effectively read-only anyway), use the value of it at the
init time to set a (new) flag in the "disable" field of that state's
cpuidle_state_usage structure and use the sysfs interface to
manipulate another (new) flag in it. This way the state is disabled
whenever the "disable" field of its cpuidle_state_usage structure is
nonzero, whatever the reason, and it is the only place to look into
to check whether or not the state has been disabled.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Daniel Lezcano <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>

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cpuidle: add poll_limit_ns to cpuidle_device structure

Add a poll_limit_ns variable to cpuidle_device structure.

Calculate and configure it in the new cpuidle_poll_time
function, in case its zero.

cpuidle: add poll_limit_ns to cpuidle_device structure

Add a poll_limit_ns variable to cpuidle_device structure.

Calculate and configure it in the new cpuidle_poll_time
function, in case its zero.

Individual governors are allowed to override this value.

Signed-off-by: Marcelo Tosatti <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Add 'above' and 'below' idle state metrics

Add two new metrics for CPU idle states, "above" and "below", to count
the number of times the given state had been asked for (or entered
from the

cpuidle: Add 'above' and 'below' idle state metrics

Add two new metrics for CPU idle states, "above" and "below", to count
the number of times the given state had been asked for (or entered
from the kernel's perspective), but the observed idle duration turned
out to be too short or too long for it (respectively).

These metrics help to estimate the quality of the CPU idle governor
in use.

Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: cpuidle/suspend: Add s2idle usage and time state attributes

Add a new attribute group called "s2idle" under the sysfs directory
of each cpuidle state that supports the ->enter_s2idle callback
an

PM: cpuidle/suspend: Add s2idle usage and time state attributes

Add a new attribute group called "s2idle" under the sysfs directory
of each cpuidle state that supports the ->enter_s2idle callback
and put two new attributes, "usage" and "time", into that group to
represent the number of times the given state was requested for
suspend-to-idle and the total time spent in suspend-to-idle after
requesting that state, respectively.

That will allow diagnostic information related to suspend-to-idle
to be collected without enabling advanced debug features and
analyzing dmesg output.

Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: Validate cpu_dev in cpuidle_add_sysfs()

If a given cpu is not in cpu_present and cpu hotplug
is disabled, arch can skip setting up the cpu_dev.

Arch cpuidle driver should pass correct cpu

cpuidle: Validate cpu_dev in cpuidle_add_sysfs()

If a given cpu is not in cpu_present and cpu hotplug
is disabled, arch can skip setting up the cpu_dev.

Arch cpuidle driver should pass correct cpu mask
for registration, but failing to do so by the driver
causes error to propagate and crash like this:

[ 30.076045] Unable to handle kernel paging request for data at address 0x00000048
[ 30.076100] Faulting instruction address: 0xc0000000007b2f30
cpu 0x4d: Vector: 300 (Data Access) at [c000003feb18b670]
pc: c0000000007b2f30: kobject_get+0x20/0x70
lr: c0000000007b3c94: kobject_add_internal+0x54/0x3f0
sp: c000003feb18b8f0
msr: 9000000000009033
dar: 48
dsisr: 40000000
current = 0xc000003fd2ed8300
paca = 0xc00000000fbab500 softe: 0 irq_happened: 0x01
pid = 1, comm = swapper/0
Linux version 4.11.0-rc2-svaidy+ (sv@sagarika) (gcc version 6.2.0
20161005 (Ubuntu 6.2.0-5ubuntu12) ) #10 SMP Sun Mar 19 00:08:09 IST 2017
enter ? for help
[c000003feb18b960] c0000000007b3c94 kobject_add_internal+0x54/0x3f0
[c000003feb18b9f0] c0000000007b43a4 kobject_init_and_add+0x64/0xa0
[c000003feb18ba70] c000000000e284f4 cpuidle_add_sysfs+0xb4/0x130
[c000003feb18baf0] c000000000e26038 cpuidle_register_device+0x118/0x1c0
[c000003feb18bb30] c000000000e26c48 cpuidle_register+0x78/0x120
[c000003feb18bbc0] c00000000168fd9c powernv_processor_idle_init+0x110/0x1c4
[c000003feb18bc40] c00000000000cff8 do_one_initcall+0x68/0x1d0
[c000003feb18bd00] c0000000016242f4 kernel_init_freeable+0x280/0x360
[c000003feb18bdc0] c00000000000d864 kernel_init+0x24/0x160
[c000003feb18be30] c00000000000b4e8 ret_from_kernel_thread+0x5c/0x74

Validating cpu_dev fixes the crash and reports correct error message like:

[ 30.163506] Failed to register cpuidle device for cpu136
[ 30.173329] Registration of powernv driver failed.

Signed-off-by: Vaidyanathan Srinivasan <[email protected]>
[ rjw: Comment massage ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: fix improper return value on error

In function cpuidle_add_state_sysfs(), variable ret takes the return
value. Its value should be negative on errors. Because ret is reset in
the loop, its

cpuidle: fix improper return value on error

In function cpuidle_add_state_sysfs(), variable ret takes the return
value. Its value should be negative on errors. Because ret is reset in
the loop, its value will be 0 during the second and after repeat of the
loop. If kzalloc() returns a NULL pointer then, it will return 0. It may
be better to explicitly assign "-ENOMEM" when the call to kzalloc()
fails.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=188901
Signed-off-by: Pan Bian <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: remove state_count field from struct cpuidle_device

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additiona

cpuidle: remove state_count field from struct cpuidle_device

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additionally
provides the C3 C-state when disconnected from AC. However, the number
of C-states shown in sysfs is fixed to the number of C-states present
at boot.
If I boot with AC connected, I always only see the C-states up to C2
even if I disconnect AC.

The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count
setting). It removes the update of dev->state_count, but sysfs uses
exactly this variable to show the C-states.

The fix is to use drv->state_count in sysfs. As this is currently the
last user of dev->state_count, this variable can be completely removed."

Remove dev->state_count as per the above.

Reported-by: Thomas Schlichter <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Kyungmin Park <[email protected]>
Acked-by: Daniel Lezcano <[email protected]>
Cc: 3.14+ <[email protected]> # 3.14+
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: fix permission for driver name sysfs node

cpuidle driver name sysfs node is read-only, so permissions should be 0444.

Signed-off-by: Mohammad Merajul Islam Molla <[email protected]>
S

cpuidle: fix permission for driver name sysfs node

cpuidle driver name sysfs node is read-only, so permissions should be 0444.

Signed-off-by: Mohammad Merajul Islam Molla <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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cpuidle: sysfs: Export target residency information

From user space, there is no way to know the target residency for each idle
state. If we want to write tools to measure the accuracy of the idle s

cpuidle: sysfs: Export target residency information

From user space, there is no way to know the target residency for each idle
state. If we want to write tools to measure the accuracy of the idle state
selection from the governor, we need this info.

As the exit latency is exported through sysfs, exporting the target residency
in the same place makes sense.

Signed-off-by: Daniel Lezcano <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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