cpufreq: interactive: fix possible Division by zero.

The following dump was seen sometimes while resuming,
the only division by zero on this function can happen after
delta_time is reassigned, since at the start of the
function, there is jump that protects against values
less than 1000.

After that, If delta_time and delta_idle == 0,
we will hit a div 0

Division by zero in kernel.
Backtrace:
[<c0057184>] (dump_backtrace+0x0/0x110) from [<c05d5ecc>] (dump_stack+0x18/0x1c)
r6:010f3000 r5:c113dfb0 r4:c004afb0 r3:c6ff0000
[<c05d5eb4>] (dump_stack+0x0/0x1c) from [<c00572cc>] (__div0+0x1c/0x20)
[<c00572b0>] (__div0+0x0/0x20) from [<c02195d4>] (Ldiv0+0x8/0x10)
[<c03dfd64>] (cpufreq_interactive_timer+0x0/0x2c0) from [<c00a7efc>] (run_timer_softirq+0x154/0x260)
[<c00a7da8>] (run_timer_softirq+0x0/0x260) from [<c00a0c8c>] (__do_softirq+0xc8/0x194)
[<c00a0bc4>] (__do_softirq+0x0/0x194) from [<c00a1008>] (irq_exit+0xb4/0xb8)
[<c00a0f54>] (irq_exit+0x0/0xb8) from [<c00584b4>] (ipi_timer+0x44/0x48)
r4:c004a040 r3:00000001
[<c0058470>] (ipi_timer+0x0/0x48) from [<c004c3e4>] (do_local_timer+0x68/0x84)
r5:c004ae2c r4:c07991e8
[<c004c37c>] (do_local_timer+0x0/0x84) from [<c0052948>] (__irq_svc+0x48/0xe0)

Change-Id: I639882db67b8d711c5710778ebc212f0f6a998e3

Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Axel Haslam <axelhaslam@ti.com>
drivers: net: wireless: bcm4330: remove HOTSPOT_VERIZON for P4LTE
sched, autogroup: stop going ahead if autogroup is disable

when autogroup is disable from the beginning,
sched_autogroup_create_attach()
  autogroup_move_group()                    <== 1
    sched_move_task()                       <== 2
      task_move_group_fair()
        set_task_rq()
          task_group()
            autogroup_task_group()

We go the whole path without doing anything useful.

Then stop going further if autogroup is disabled.

But there will be a race window between 1 and 2, in which
sysctl_sched_autogroup_enabled is enabled. This issue
will be toke by following patch.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
sched: refactor task_group()

move cgroup-related task group finding to cgroup_task_group().
No function change.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
sched, autogroup: runtime enable/disable tuning fix

Now enable/disable autogroup at runtime is just a flag,
it doesn't take effect on current process of the system.

when disable autogroup:

vanilla:
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 1046 test1     20   0 25544  844  276 R 50.0  0.0   0:23.30 bash
 1044 test2     20   0 25544  860  280 R 25.2  0.0   0:20.55 bash
 1045 test2     20   0 25544  864  284 R 24.8  0.0   0:17.48 bash

patched:
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  991 test1     20   0 25544  844  276 R 31.7  0.0   2:05.93 bash
  992 test2     20   0 25544  848  276 R 31.7  0.0   1:16.84 bash
  994 test2     20   0 25544  856  284 R 29.8  0.0   1:02.67 bash

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
sched: Don't call task_group() too many times in set_task_rq()

It improves perfomance, especially if autogroup is enabled.

The size of set_task_rq() was 0x180 and now it is 0xa0.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1321020240-3874331-1-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CPU hotplug, re-create sysfs directory and symlinks

commit 27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034 upstream.

When we discover CPUs that are affected by each other's
frequency/voltage transitions, the first CPU gets a sysfs directory
created, and rest of the siblings get symlinks. Currently, when we
hotplug off only the first CPU, all of the symlinks and the sysfs
directory gets removed. Even though rest of the siblings are still
online and functional, they are orphaned, and no longer governed by
cpufreq.

This patch, given the above scenario, creates a sysfs directory for
the first sibling and symlinks for the rest of the siblings.

Please note the recursive call, it was rather too ugly to roll it
out. And the removal of redundant NULL setting (it is already taken
care of near the top of the function).

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
cpufreq interactive governor: Update target frequency calculation

Updated target frequency calculation algorithm to take into account
current rate CPU is running at:

- When CPU is running below go_maxspeed_load threshold, adjust the
target frequency based on current rate to reach tunable sustainable
load (instead of applying cpu load to max possible cpu rate).

Tuned by setting new node ("0" falls back to using max_rate):
/sys/devices/system/cpu/cpufreq/interactive/sustain_load

- When CPU is running at/above go_maxspeed_load threshold, ramp the
target frequency starting from current exponentially with tunable base
(instead of immediate jump to maximum cpu rate).

Tuned by setting new node ("0" falls back to jump to max_rate):
/sys/devices/system/cpu/cpufreq/interactive/boost_factor

Defaults for the new tunning parameters are set to "0" - so no changes
in governor default behavior.

Original-Change-Id: Ie845d747239ba177e6f06b73965c3213649f8135
Reviewed-on: http://git-master/r/34583
Reviewed-by: Aleksandr Frid <afrid@nvidia.com>
Tested-by: Aleksandr Frid <afrid@nvidia.com>
Reviewed-by: Chih-Lung Huang <lhuang@nvidia.com>
Reviewed-by: Scott Williams <scwilliams@nvidia.com>
Reviewed-by: Narendra Damahe <ndamahe@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
cpufreq: interactive: support shared CPU scaling

Change-Id: Id5267f04067bf023f6b140b4de2e88ef7287e941
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: remove debug trace code

Remove debug trace code in preparation of upstreaming

Change-Id: I0905885e75031f5e9d7cb06878fb68c1fd06d4fe
Signed-off-by: Allen Martin <amartin@nvidia.com>
cpufreq: interactive: Add error checking on sysfs interfaces

This adds better error checking on tunable parameters on sysfs
interfaces.  Also fixes return value from these functions, previously
on success they would return 0 which would cause a infinite loop.

Change-Id: Ic05038492166f8673d007202092471f98a2f0dfa
Signed-off-by: Allen Martin <amartin@nvidia.com>
cpufreq: interactive: add sysfs control for timer rate

Add a new sysfs control that tunes the rate of the timer used to
increase cpu frequency

Change-Id: I1aa13ae54bb43aff5b3688984d2955f56aae1658
Signed-off-by: Allen Martin <amartin@nvidia.com>
cpufreq: interactive: cleanup checkpatch warnings

Cleanup some style warnings reported by checkpatch

Change-Id: Ie2e6903d52867fb3347e009d7efa3bc4ca755cea
Signed-off-by: Allen Martin <amartin@nvidia.com>

Conflicts:

	drivers/cpufreq/cpufreq_interactive.c
cpufreq: interactive: fix checkpatch warnings on long lines

Fix up checkpatch warning introduced by long lines in timer_rate
patch.

Change-Id: I22b105dafb1b49390799bb7577464da03f0f8afb
Signed-off-by: Allen Martin <amartin@nvidia.com>
cpufreq: interactive: Fix handling of SMP where CPUs must scale in tandem

The interactive governor relies on quirks of the Tegra 2 cpufreq
implementation for handling SMP systems where the CPUs do not have
separate rate controls.  It needs to determine the maximum rate
for all CPUs covered by the policy and set that speed.

Change-Id: I1ed9fa171e5a9c45a1fa5944e3fa823eb157e81f
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive governor: go to intermediate hi speed before max

* Add attribute hispeed_freq, which defaults to max.

* Rename go_maxspeed_load to go_hispeed_load.

* If hit go_hispeed_load and at min speed, go to hispeed_freq;
  if hit go_hispeed_load and already above min speed go to max
  speed.

Change-Id: I1050dec5f013fc1177387352ba787a7e1c68703e
Signed-off-by: Todd Poynor <toddpoynor@google.com>

Conflicts:

	drivers/cpufreq/cpufreq_interactive.c
cpufreq: interactive governor: default 20ms timer

Change-Id: Ie9952f07b38667f2932474090044195c57976faa
Signed-off-by: Todd Poynor <toddpoynor@google.com>

Conflicts:

	drivers/cpufreq/cpufreq_interactive.c
cpufreq: use system_wq instead of dedicated workqueues

With cmwq, there's no reason for cpufreq drivers to use separate
workqueues.  Remove the dedicated workqueues from cpufreq_conservative
and cpufreq_ondemand and use system_wq instead.  The work items are
already sync canceled on stop, so it's already guaranteed that no work
is running on module exit.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dave Jones <davej@redhat.com>
Cc: cpufreq@vger.kernel.org
[CPUFREQ] calculate delay after dbs_check_cpu

calculate ondemand delay after dbs_check_cpu call because it can
modify rate_mult value

use freq_lo_jiffies value for the sub sample period of powersave_bias mode

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Dave Jones <davej@redhat.com>
[CPUFREQ] Remove deprecated sysfs file sampling_rate_max

Marked deprecated for quite a while now...

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org