saner replacement for debugfs_rename()

Existing primitive has several problems:
1) calling conventions are clumsy - it returns a dentry reference
that is either identical to its second argument or

saner replacement for debugfs_rename()

Existing primitive has several problems:
1) calling conventions are clumsy - it returns a dentry reference
that is either identical to its second argument or is an ERR_PTR(-E...);
in both cases no refcount changes happen. Inconvenient for users and
bug-prone; it would be better to have it return 0 on success and -E... on
failure.
2) it allows cross-directory moves; however, no such caller have
ever materialized and considering the way debugfs is used, it's unlikely
to happen in the future. What's more, any such caller would have fun
issues to deal with wrt interplay with recursive removal. It also makes
the calling conventions clumsier...
3) tautological rename fails; the callers have no race-free way
to deal with that.
4) new name must have been formed by the caller; quite a few
callers have it done by sprintf/kasprintf/etc., ending up with considerable
boilerplate.

Proposed replacement: int debugfs_change_name(dentry, fmt, ...). All callers
convert to that easily, and it's simpler internally.

IMO debugfs_rename() should go; if we ever get a real-world use case for
cross-directory moves in debugfs, we can always look into the right way
to handle that.

Signed-off-by: Al Viro <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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OPP: debugfs: Fix warning around icc_get_name()

If the kernel isn't built with interconnect support, icc_get_name()
returns NULL and we get following warning:

drivers/opp/debugfs.c: In function 'bw

OPP: debugfs: Fix warning around icc_get_name()

If the kernel isn't built with interconnect support, icc_get_name()
returns NULL and we get following warning:

drivers/opp/debugfs.c: In function 'bw_name_read':
drivers/opp/debugfs.c:43:42: error: '%.62s' directive argument is null [-Werror=format-overflow=]
i = scnprintf(buf, sizeof(buf), "%.62s\n", icc_get_name(path));

Fix it.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: 0430b1d5704b0 ("opp: Expose bandwidth information via debugfs")
Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Dhruva Gole <[email protected]>

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OPP: debugfs: Fix warning with W=1 builds

We currently get the following warning:

debugfs.c:105:54: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of siz

OPP: debugfs: Fix warning with W=1 builds

We currently get the following warning:

debugfs.c:105:54: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 8 [-Werror=format-truncation=]
snprintf(name, sizeof(name), "supply-%d", i);
^~
debugfs.c:105:46: note: directive argument in the range [-2147483644, 2147483646]
snprintf(name, sizeof(name), "supply-%d", i);
^~~~~~~~~~~
debugfs.c:105:17: note: 'snprintf' output between 9 and 19 bytes into a destination of size 15
snprintf(name, sizeof(name), "supply-%d", i);

Fix this and other potential issues it by allocating larger arrays.
Use the exact string format to allocate the arrays without getting into
these issues again.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Dhruva Gole <[email protected]>

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OPP: debugfs: Fix warning with W=1 builds

We currently get the following warning:

debugfs.c: In function ‘opp_debug_create_one’:
debugfs.c:63:42: warning: ‘%.1d’ directive output may be truncated w

OPP: debugfs: Fix warning with W=1 builds

We currently get the following warning:

debugfs.c: In function ‘opp_debug_create_one’:
debugfs.c:63:42: warning: ‘%.1d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 2 [-Wformat-truncation=]
snprintf(name, sizeof(name), "icc-path-%.1d", i);
^~~~
debugfs.c:63:32: note: directive argument in the range [0, 2147483647]
snprintf(name, sizeof(name), "icc-path-%.1d", i);
^~~~~~~~~~~~~~~
debugfs.c:63:3: note: ‘snprintf’ output between 11 and 20 bytes into a destination of size 11
snprintf(name, sizeof(name), "icc-path-%.1d", i);

Fix it by increasing size of the `name` array.

Signed-off-by: Viresh Kumar <[email protected]>

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OPP: Simplify the over-designed pstate <-> level dance

While adding support for "performance states" in the OPP and genpd core,
it was decided to set the `pstate` field via genpd's
pm_genpd_opp_to_p

OPP: Simplify the over-designed pstate <-> level dance

While adding support for "performance states" in the OPP and genpd core,
it was decided to set the `pstate` field via genpd's
pm_genpd_opp_to_performance_state() helper, to allow platforms to set
`pstate` even if they don't have a corresponding `level` field in the DT
OPP tables (More details are present in commit 6e41766a6a50 ("PM /
Domain: Implement of_genpd_opp_to_performance_state()")).

Revisiting that five years later clearly suggests that it was
over-designed as all current users are eventually using the `level`
value only.

The previous commit already added necessary checks to make sure pstate
is only used for genpd tables. Lets now simplify this a little, and use
`level` directly and remove `pstate` field altogether.

Suggested-by: Ulf Hansson <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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OPP: pstate is only valid for genpd OPP tables

It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the sam

OPP: pstate is only valid for genpd OPP tables

It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the same at various places.

Add checks in place to verify that and make it clear to the reader.

Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Tested-by: Bjorn Andersson <[email protected]>

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OPP: fix error checking in opp_migrate_dentry()

Since commit ff9fb72bc077 ("debugfs: return error values, not NULL")
changed return value of debugfs_rename() in error cases from %NULL to
%ERR_PTR(-E

OPP: fix error checking in opp_migrate_dentry()

Since commit ff9fb72bc077 ("debugfs: return error values, not NULL")
changed return value of debugfs_rename() in error cases from %NULL to
%ERR_PTR(-ERROR), we should also check error values instead of NULL.

Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Signed-off-by: Qi Zheng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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OPP: fix error checking in opp_migrate_dentry()

Since commit ff9fb72bc077 ("debugfs: return error values,
not NULL") changed return value of debugfs_rename() in
error cases from %NULL to %ERR_PTR(-E

OPP: fix error checking in opp_migrate_dentry()

Since commit ff9fb72bc077 ("debugfs: return error values,
not NULL") changed return value of debugfs_rename() in
error cases from %NULL to %ERR_PTR(-ERROR), we should
also check error values instead of NULL.

Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Signed-off-by: Qi Zheng <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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OPP: Allow multiple clocks for a device

This patch adds support to allow multiple clocks for a device.

The design is pretty much similar to how this is done for regulators,
and platforms can supply

OPP: Allow multiple clocks for a device

This patch adds support to allow multiple clocks for a device.

The design is pretty much similar to how this is done for regulators,
and platforms can supply their own version of the config_clks() callback
if they have multiple clocks for their device. The core manages the
calls via opp_table->config_clks() eventually.

We have kept both "clk" and "clks" fields in the OPP table structure and
the reason is provided as a comment in _opp_set_clknames(). The same
isn't done for "rates" though and we use rates[0] at most of the places
now.

Co-developed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Jon Hunter <[email protected]>
Tested-by: Dmitry Osipenko <[email protected]>
Tested-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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opp: use list iterator only inside the loop

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the l

opp: use list iterator only inside the loop

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate dedicated pointer variable [1].

In this case, use a new variable 'iter' as the list iterator, while
use the old variable 'new_dev' as a dedicated pointer to point to the
found entry. And BUG_ON(!new_dev);.

[1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/

Signed-off-by: Xiaomeng Tong <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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OPP: Add "opp-microwatt" supporting code

Add new property to the OPP: power value. The OPP entry in the DT can have
"opp-microwatt". Add the needed code to handle this new property in the
existing i

OPP: Add "opp-microwatt" supporting code

Add new property to the OPP: power value. The OPP entry in the DT can have
"opp-microwatt". Add the needed code to handle this new property in the
existing infrastructure.

Signed-off-by: Lukasz Luba <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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opp: Expose of-node's name in debugfs

It is difficult to find which OPPs are active at the moment, specially
if there are multiple OPPs with same frequency available in the device
tree (controlled b

opp: Expose of-node's name in debugfs

It is difficult to find which OPPs are active at the moment, specially
if there are multiple OPPs with same frequency available in the device
tree (controlled by supported hardware feature).

Expose name of the DT node to find out the exact OPP.

While at it, also expose level field.

Reported-by: Leo Yan <[email protected]>
Tested-by: Leo Yan <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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opp: Expose bandwidth information via debugfs

Expose the bandwidth information as well via debugfs.

Signed-off-by: Viresh Kumar <[email protected]>
Signed-off-by: Georgi Djakov <georgi.djakov

opp: Expose bandwidth information via debugfs

Expose the bandwidth information as well via debugfs.

Signed-off-by: Viresh Kumar <[email protected]>
Signed-off-by: Georgi Djakov <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Enrico Weigelt <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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opp: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic shou

opp: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: Viresh Kumar <[email protected]>
Cc: Nishanth Menon <[email protected]>
Cc: Stephen Boyd <[email protected]>
Cc: [email protected]
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

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PM / OPP: "opp-hz" is optional for power domains

"opp-hz" property is optional for power domains now and we shouldn't
error out if it is missing for power domains.

This patch creates two new routin

PM / OPP: "opp-hz" is optional for power domains

"opp-hz" property is optional for power domains now and we shouldn't
error out if it is missing for power domains.

This patch creates two new routines, _get_opp_count() and
_opp_is_duplicate(), by separating existing code from their parent
functions. Also skip duplicate OPP check for power domain OPPs as they
may not have any the "opp-hz" field, but a platform specific performance
state binding to uniquely identify OPP nodes.

By default the debugfs OPP nodes are named using the "rate" value, but
that isn't possible for the power domain OPP nodes and hence they use
the index of the OPP node in the OPP node list instead.

Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM / OPP: Support updating performance state of device's power domain

The genpd framework now provides an API to request device's power
domain to update its performance state. Use that interface fr

PM / OPP: Support updating performance state of device's power domain

The genpd framework now provides an API to request device's power
domain to update its performance state. Use that interface from the
OPP core for devices whose power domains support performance states.

Note that this commit doesn't add any mechanism by which performance
states are made available to the OPP core. That would be done by a
later commit.

Note that the current implementation is restricted to the case where
the device doesn't have separate regulators for itself. We shouldn't
over engineer the code before we have real use case for them. We can
always come back and add more code to support such cases later on.

Tested-by: Rajendra Nayak <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM / OPP: Use snprintf() to avoid kasprintf() and kfree()

Use snprintf() to avoid unnecessary initializations, avoid calling
kfree().

Signed-off-by: Arvind Yadav <[email protected]>
Acked-b

PM / OPP: Use snprintf() to avoid kasprintf() and kfree()

Use snprintf() to avoid unnecessary initializations, avoid calling
kfree().

Signed-off-by: Arvind Yadav <[email protected]>
Acked-by: Viresh Kumar <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM / OPP: Move the OPP directory out of power/

The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fi

PM / OPP: Move the OPP directory out of power/

The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.

Signed-off-by: Viresh Kumar <[email protected]>
Acked-by: Stephen Boyd <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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