cpufreq: Save user policy min/max instead of policy min/max during hotplug

When a CPU is hotplugged off, various fields of the policy are saved so
that they can be restored when the CPU is hotplugged back in.

The existing code saves the policy min/max field during hotplug remove and
restores it into user policy min/max during hotplug add. This results in
the loss of the user policy min/max values across a hotplug remove/add.

Fix it by saving the user policy min/max instead of policy min/max during
hotplug remove. During a hotplug add, after user policy min/max is
restored, the policy min/max is already recomputed. So, there's no risk of
going beyound any limits imposed by the CPUFREQ_ADJUST/INCOMPATIBLE
notifiers.

Change-Id: Ib8e09fa324c1f80f095c5754b5dcf2685e8e4a66
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
cpufreq: Introduce new relation for freq selection

Introduce CPUFREQ_RELATION_C for frequency selection.
It selects the frequency with the minimum euclidean distance
to target. In case of equal distance between 2 frequencies,
it will select the greater freq.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
cpufreq: interactive: allow arbitrary speed / delay mappings

Accept a string of delays and speeds at which to apply the delay before
raising each step above hispeed. For example, "80000 1300000:200000
1500000:40000" means that the delay at or above 1GHz, until 1.3GHz is 80 msecs,
the delay until 1.5GHz is 200 msecs and the delay at or above 1.5GHz is 40
msecs when hispeed_freq is 1GHz.

[toddpoynor@google.com: add documentation]
Change-Id: Ifeebede8b1acbdd0a53e5c6916bccbf764dc854f
Signed-off-by: Minsung Kim <ms925.kim@samsung.com>
cpufreq: interactive: add io_is_busy interface

Previously the idle time returned from get_cpu_idle_time_us included the
iowait time. So the iowait time was always calculated as idle time.

But now the idle time returned from get_cpu_idle_time_us does not include
the iowait time anymore because of below commit which cause the iowait time
always calculated as busy time:
    6beea0c nohz: Fix update_ts_time_stat idle accounting

Add the io_is_busy interface, as does the ondemand governor, and let the user
configure the iowait time as busy or idle through the io_is_busy sysfs
interface.

By default, io_is_busy is disabled.

[toddpoynor@google.com: minor updates]
Change-Id: If7d70ff864c43bc9c8d7fd7cfc66f930d339f9b4
Signed-off-by: Lianwei Wang <lian-wei.wang@motorola.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: fix crash on error paths in get_tokenized_data

Use separate variable for error code, free proper pointer.

Change-Id: Ia83cccb195997789ac6afbf5b8761f7b278196d6
Reported-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: base above_hispeed_delay on target freq, not current

Time to wait should be based on the intended target speed, not the
actual speed (which may be held high by another CPU).

Change-Id: Ifc5bb55d06adddb9a02af90af05398a78f282272
Reported-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: fix uninitialized spinlock

Add missing spinlock init

Backtrace:
[<c0011ce4>] (dump_backtrace+0x0/0x10c) from [<c0662a68>] (dump_stack+0x18/0x1c)
 r6:00000032 r5:c0bd09ec r4:e6848000 r3:00000000
[<c0662a50>] (dump_stack+0x0/0x1c) from [<c06670b0>] (spin_dump+0x80/0x94)
[<c0667030>] (spin_dump+0x0/0x94) from [<c06670f0>] (spin_bug+0x2c/0x30)
 r5:c08f91fc r4:c0bd09ec
[<c06670c4>] (spin_bug+0x0/0x30) from [<c0245f74>] (do_raw_spin_unlock+0x88/0xcc)
 r5:e547bac0 r4:c0bd09ec
[<c0245eec>] (do_raw_spin_unlock+0x0/0xcc) from [<c066c9cc>] (_raw_spin_unlock_irqrestore+0x14/0x40)
 r5:e547bac0 r4:60000013
[<c066c9b8>] (_raw_spin_unlock_irqrestore+0x0/0x40) from [<c044b884>] (store_above_hispeed_delay+0x6c/0x80)
 r4:c0b4cf78 r3:00000007
[<c044b818>] (store_above_hispeed_delay+0x0/0x80) from [<c0235d24>] (kobj_attr_store+0x1c/0x28)
 r7:e68ff000 r6:00000032 r5:e58137c0 r4:e61cde80
[<c0235d08>] (kobj_attr_store+0x0/0x28) from [<c0156b78>] (sysfs_write_file+0x104/0x184)
[<c0156a74>] (sysfs_write_file+0x0/0x184) from [<c0100680>] (vfs_write+0xb0/0x140)
[<c01005d0>] (vfs_write+0x0/0x140) from [<c0100900>] (sys_write+0x44/0x70)
 r8:00000000 r7:00000004 r6:00000032 r5:bee43c90 r4:e5600300
[<c01008bc>] (sys_write+0x0/0x70) from [<c000e400>] (ret_fast_syscall+0x0/0x30)
 r9:e6842000 r8:c000e584 r6:00000032 r5:bee43c90 r4:00000009

Change-Id: I80a1e0b3fecb24adba501ff44f568479deeff7fa
Signed-off-by: Minsung Kim <ms925.kim@samsung.com>
cpufreq: interactive: handle errors from cpufreq_frequency_table_target

Add checks for error return from cpufreq_frequency_table_target, and be
less noisy on the existing call with an error check.  CPU hotplug and
system shutdown may cause this call to return -EINVAL.

Bug: 8613560
Change-Id: Id78d8829920462c0db1c7e14e717d91740d6cb44
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: reduce chance of zero time delta on load eval

Reschedule load sampling timer after timestamp of sample start taken,
hold spinlock across entire sequence to avoid preemption.  Avoid the
WARN for zero time delta in the load sampling timer function.

Change-Id: Idc10a756f09141decb6df92669521a1ebf0dbc10
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: avoid underflow on active time calculation

Check for idle time delta less than elapsed time delta, avoid
underflow computing active time.

Change-Id: I3e4c6ef1ad794eec49ed379c0c50fa727fd6ad28
Signed-off-by: Minsung Kim <ms925.kim@samsung.com>
cpufreq: interactive: fix race on cpufreq TRANSITION notifier

The cpufreq TRANSTION notifier callback does not check the
governor_enabled state on affected CPUS, which will case
kernel panic in update_load because the policy object maybe
NULL or invalid when governor_enabled is false.

Change-Id: Ie0f1718124f61e2f9b5da57abc6981ada5b83908
Signed-off-by: Lianwei Wang <a22439@motorola.com>
cpufreq: interactive: resched timer if max freq raised

When the policy max freq is raised, and before the timer is
rescheduled in idle callback, the cpu freq may stuck at a
lower freq.

The target_freq shall be updated too, else on a high load
situation, the new_freq is always equal to target_freq and
which will cause freq stuck at a lower freq too.

Reschedule the timer on gov limits callback.

Change-Id: I6c187001ab43e859731429b64f75a74eebc37a24
Signed-off-by: Lianwei Wang <a22439@motorola.com>
cpufreq: interactive: fix show_target_loads and show_above_hispeed_delay

Remove a trailing whitespace from target_loads and above_hispeed_delay. Problem
happens when user-space program tried to restore parameters that saved before
changing parameters. In this case was returned error(EINVAL).

Change-Id: I5a74e3824602cd6f2b74651adda5ec1b627e61e9
Signed-off-by: Minsung Kim <ms925.kim@samsung.com>
cpufreq: interactive: Remove unnecessary cpu_online() check

Cpufreq no longer calls governor callback for offlined cpus. i.e. All
policy->cpus are guaranteed to be online. Hence we don't need explicit check to
see if cpu is online or not.

Change-Id: I9ad85ea4addd5b4a40952e59ed730dd15e328690
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: interactive: Move definition of cpufreq_gov_interactive downwards

This moves definition of cpufreq_gov_interactive towards the bottom of file, so
that we don't have to add prototype of cpufreq_governor_interactive() in the
beginning of file.

Change-Id: I04bd1004954eb36502c5cd7e35d3d7274cddaf95
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: Interactive: Implement per policy instances of governor

If we have a multi-package system, where we have multiple instances of struct
policy (per package), currently we can't have multiple instances of same
governor. i.e. We can't have multiple instances of Interactive governor for
multiple packages.

This is a bottleneck for multicluster system, where we want different packages
to use Interactive governor, but with different tunables.

This patch uses the infrastructure provided by earlier patches pushed in
Mainline in v3.10-rc1/rc2 and implements per policy instances of Interactive
governor.

Change-Id: I70436d4a5a45c6cb6edf37f3e46d0b9fbc930982
[toddpoynor@google.com: merge with later code, minor changes]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: interactive: delete timers for GOV_START

Make sure that timers cpu_timer and cpu_slack_timer
deactivated before addition of new.

Change-Id: If31c4049606871df6f00efdc24b1d713c86a6f69
Signed-off-by: Shridhar Rasal <srasal@nvidia.com>
Signed-off-by: Bharat Nihalani <bnihalani@nvidia.com>
cpufreq: interactive: fix compiling warnings

The gcc warns like:

  cpufreq_interactive.c:745:6: warning: operation on 'ret' may be undefined [-Wsequence-point]

It was introduced by commit cf0fad49d17cb8273ce555dd5b7afab67d7923bf.

Since sprintf(...) just return 1 (one character) in this case, ret should not changed.
Just discarding the result of sprintf(...) leads to the result that
the committer of cf0fad49d17cb8273ce555dd5b7afab67d7923bf wants.

Change-Id: Ifed1cef6d6a31c3ed23dad03a567b3b9eddf3a57
Signed-off-by: Chih-Wei Huang <cwhuang@android-x86.org>