linux-toradex.git/drivers/cpufreq/freq_table.c, branch v5.0

cpufreq: Drop cpufreq_table_validate_and_show()

2018-04-10T06:40:45+00:00

This isn't used anymore. Remove the helper and update documentation
accordingly.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Validate frequency table in the core

2018-02-27T17:22:12+00:00

By design, cpufreq drivers are responsible for calling
cpufreq_frequency_table_cpuinfo() from their ->init()
callbacks to validate the frequency table.

However, if a cpufreq driver is buggy and fails to do so properly, it
lead to unexpected behavior of the driver or the cpufreq core at a
later point in time.  It would be better if the core could
validate the frequency table during driver initialization.

To that end, introduce cpufreq_table_validate_and_sort() and make
the cpufreq core call it right after invoking the ->init() callback
of the driver and destroy the cpufreq policy if the table is invalid.

For the time being the validation of the table happens twice, once
from the driver and then from the core.  The individual drivers will
be updated separately to drop table validation if they don't need it
for other reasons.

The frequency table is marked "sorted" or "unsorted" by the new helper
now instead of in cpufreq_table_validate_and_show(), as it should only
be done after validating the table (which the drivers won't do going
forward).

Signed-off-by: Viresh Kumar 
[ rjw: Subject/changelog ]
Signed-off-by: Rafael J. Wysocki

cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()

2018-02-08T09:21:39+00:00

Pointer subtraction is slow and tedious. Therefore, replace all instances
where cpufreq_for_each_{valid_,}entry loops contained such substractions
with an iteration macro providing an index to the frequency_table entry.

Suggested-by: Al Viro 
Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk
Acked-by: Viresh Kumar 
Signed-off-by: Dominik Brodowski 
Signed-off-by: Rafael J. Wysocki

cpufreq: Handle sorted frequency tables more efficiently

2016-07-06T22:13:20+00:00

cpufreq drivers aren't required to provide a sorted frequency table
today, and even the ones which provide a sorted table aren't handled
efficiently by cpufreq core.

This patch adds infrastructure to verify if the freq-table provided by
the drivers is sorted or not, and use efficient helpers if they are
sorted.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Return index from cpufreq_frequency_table_target()

2016-06-08T22:58:06+00:00

This routine can't fail unless the frequency table is invalid and
doesn't contain any valid entries.

Make it return the index and WARN() in case it is used for an invalid
table.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Drop freq-table param to cpufreq_frequency_table_target()

2016-06-08T22:58:06+00:00

The policy already has this pointer set, use it instead.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Remove cpufreq_frequency_get_table()

2016-06-08T22:58:05+00:00

Most of the callers of cpufreq_frequency_get_table() already have the
pointer to a valid 'policy' structure and they don't really need to go
through the per-cpu variable first and then a check to validate the
frequency, in order to find the freq-table for the policy.

Directly use the policy->freq_table field instead for them.

Only one user of that API is left after above changes, cpu_cooling.c and
it accesses the freq_table in a racy way as the policy can get freed in
between.

Fix it by using cpufreq_cpu_get() properly.

Since there are no more users of cpufreq_frequency_get_table() left, get
rid of it.

Signed-off-by: Viresh Kumar 
Acked-by: Javi Merino  (cpu_cooling.c)
Signed-off-by: Rafael J. Wysocki

cpufreq: Unexport cpufreq_frequency_table_cpuinfo()

2016-06-02T21:24:41+00:00

All cpufreq drivers with a freq-table are migrated to use
cpufreq_table_validate_and_show() long back and the routine
cpufreq_frequency_table_cpuinfo() isn't used outside of cpufreq core
now.

Unexport it and update Documentation as well.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Allow drivers to enable boost support after registering driver

2015-08-07T01:25:23+00:00

In some cases it wouldn't be known at time of driver registration, if
the driver needs to support boost frequencies.

For example, while getting boost information from DT with opp-v2
bindings, we need to parse the bindings for all the CPUs to know if
turbo/boost OPPs are supported or not.

One way out to do that efficiently is to delay supporting boost mode
(i.e. creating /sys/devices/system/cpu/cpufreq/boost file), until the
time OPP bindings are parsed.

At that point, the driver can enable boost support. This can be done at
->init(), where the frequency table is created.

To do that, the driver requires few APIs from cpufreq core that let him
do this. This patch provides these APIs.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

cpufreq: Allow freq_table to be obtained for offline CPUs

2015-07-09T23:43:27+00:00

Users of freq table may want to access it for any CPU from
policy->related_cpus mask. One such user is cpu-cooling layer. It gets a
list of 'clip_cpus' (equivalent to policy->related_cpus) during
registration and tries to get freq_table for the first CPU of this mask.

If the CPU, for which it tries to fetch freq_table, is offline,
cpufreq_frequency_get_table() fails. This happens because it relies on
cpufreq_cpu_get_raw() for its functioning which returns policy only for
online CPUs.

The fix is to access the policy data structure for the given CPU
directly (which also returns a valid policy for offline CPUs), but the
policy itself has to be active (meaning that at least one CPU using it
is online) for the frequency table to be returned.

Because we will be using 'cpufreq_cpu_data' now, which is internal to
the cpufreq core, move cpufreq_frequency_get_table() to cpufreq.c.

Reported-and-tested-by: Pi-Cheng Chen 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki