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>

Conflicts:
	drivers/cpufreq/cpufreq_interactive.c
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>

Conflicts:

	drivers/cpufreq/cpufreq_interactive.c
cpufreq: interactive: Remove trace event from idle_start handler

Removed the trace_cpufreq_interactive_idle_start.
Also fix a crash resulting from accessing NULL policy before taking
the pcpu->enable_sem lock. The policy can be NULL if the core is
hotplugged out before the enable_sem lock is taken.

Change-Id: I7e2809cc016b3b383a44cdf3c697013e2d2b5417
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
(cherry picked from commit 3b7992b90216c74a9ae9ce0df90bc446687a2313)

Conflicts:
	drivers/cpufreq/cpufreq_interactive.c
cpufreq: interactive: Add a sampling_down_factor for max frequencies

Change min_sample_time to 100ms when running at max

Change-Id: Ia7e35b0625bedf20e7ef3a1f52e5828ffbfed93e
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Allow 1 ms error in above_hispeed_delay comparisons

Allow for an error of 1 ms while taking into account
above_hispeed_delay for a frequency

Change-Id: I744e44387152e4efb5978df4f2b9533bf79d4582
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Reset floor_validate_time if busy at max for 100ms

When the interactive governor selects to run at max frequency it doesn't
re-schedule the timer until it hits an idle. This change checks if the CPU
has been continuously busy for last 100ms on hitting an idle start. If yes,
then floor_validate_time is reset so that the CPU stays at max frequency
for at least another 100 ms before stepping down.
This is an important feature for detecting CPU intensive workloads which
require high frequencies for achieving better performance.

Change-Id: I7d48ffbc3d50a80af9be3bf94667ee3d0120b763
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>

Conflicts:
	drivers/cpufreq/cpufreq_interactive.c