Commit Graph

59 Commits

Author SHA1 Message Date
Viresh Kumar
952da0c9ab cpufreq: powernv: Migrate to ->exit() callback instead of ->stop_cpu()
Commit 367dc4aa93 ("cpufreq: Add stop CPU callback to cpufreq_driver
interface") added the ->stop_cpu() callback to allow the drivers to do
clean up before the CPU is completely down and its state can't be
modified.

At that time the CPU hotplug framework used to call the cpufreq core's
registered notifier for different events like CPU_DOWN_PREPARE and
CPU_POST_DEAD. The ->stop_cpu() callback was called during the
CPU_DOWN_PREPARE event.

This is no longer the case, cpuhp_cpufreq_offline() is called only
once by the CPU hotplug core now and we don't really need two
separate callbacks for cpufreq drivers, i.e. ->stop_cpu() and
->exit(), as everything can be done from the ->exit() callback
itself.

Migrate to using the ->exit() callback instead of ->stop_cpu().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Minor changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-30 18:51:43 +02:00
Srikar Dronamraju
a2d0230b91 cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
The patch avoids allocating cpufreq_policy on stack hence fixing frame
size overflow in 'powernv_cpufreq_reboot_notifier':

  drivers/cpufreq/powernv-cpufreq.c: In function powernv_cpufreq_reboot_notifier:
  drivers/cpufreq/powernv-cpufreq.c:906:1: error: the frame size of 2064 bytes is larger than 2048 bytes

Fixes: cf30af76 ("cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200922080254.41497-1-srikar@linux.vnet.ibm.com
2020-10-08 21:17:16 +11:00
Wei Yongjun
133c6c84f2 cpufreq: powernv: Make some symbols static
The sparse tool complains as follows:

drivers/cpufreq/powernv-cpufreq.c:88:1: warning:
 symbol 'pstate_revmap' was not declared. Should it be static?
drivers/cpufreq/powernv-cpufreq.c:383:18: warning:
 symbol 'cpufreq_freq_attr_cpuinfo_nominal_freq' was not declared. Should it be static?
drivers/cpufreq/powernv-cpufreq.c:669:6: warning:
 symbol 'gpstate_timer_handler' was not declared. Should it be static?
drivers/cpufreq/powernv-cpufreq.c:902:6: warning:
 symbol 'powernv_cpufreq_work_fn' was not declared. Should it be static?

Those symbols are not used outside of this file, so mark
them static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-15 17:27:15 +02:00
Lee Jones
44bd9a30ef cpufreq: powernv-cpufreq: Fix a bunch of kerneldoc related issues
Repair problems with formatting and missing attributes/parameters, and
demote header comments which do not meet the required standards
applicable to kerneldoc.

Fixes the following W=1 kernel build warning(s):

 drivers/cpufreq/powernv-cpufreq.c:84: warning: Function parameter or member 'last_lpstate_idx' not described in 'global_pstate_info'
 drivers/cpufreq/powernv-cpufreq.c:84: warning: Function parameter or member 'last_gpstate_idx' not described in 'global_pstate_info'
 drivers/cpufreq/powernv-cpufreq.c:84: warning: Function parameter or member 'policy' not described in 'global_pstate_info'
 drivers/cpufreq/powernv-cpufreq.c:182: warning: Function parameter or member 'i' not described in 'idx_to_pstate'
 drivers/cpufreq/powernv-cpufreq.c:201: warning: Function parameter or member 'pstate' not described in 'pstate_to_idx'
 drivers/cpufreq/powernv-cpufreq.c:670: warning: Function parameter or member 't' not described in 'gpstate_timer_handler'
 drivers/cpufreq/powernv-cpufreq.c:670: warning: Excess function parameter 'data' description in 'gpstate_timer_handler'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-15 15:17:06 +02:00
Pratik Rajesh Sampat
d95fe371ec cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn
The patch avoids allocating cpufreq_policy on stack hence fixing frame
size overflow in 'powernv_cpufreq_work_fn'

Fixes: 227942809b ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
Signed-off-by: Pratik Rajesh Sampat <psampat@linux.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200316135743.57735-1-psampat@linux.ibm.com
2020-03-25 12:09:34 +11:00
Oliver O'Halloran
966c08de7c cpufreq: powernv: Fix unsafe notifiers
The PowerNV cpufreq driver registers two notifiers: one to catch
throttle messages from the OCC and one to bump the CPU frequency back
to normal before a reboot. Both require the cpufreq driver to be
registered in order to function since the notifier callbacks use
various cpufreq_*() functions.

Right now we register both notifiers before we've initialised the
driver. This seems to work, but we should head off any protential
problems by registering the notifiers after the driver is initialised.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200206062622.28235-2-oohall@gmail.com
2020-03-13 21:13:11 +11:00
Oliver O'Halloran
d0a72efac8 cpufreq: powernv: Fix use-after-free
The cpufreq driver has a use-after-free that we can hit if:

a) There's an OCC message pending when the notifier is registered, and
b) The cpufreq driver fails to register with the core.

When a) occurs the notifier schedules a workqueue item to handle the
message. The backing work_struct is located on chips[].throttle and
when b) happens we clean up by freeing the array. Once we get to
the (now free) queued item and the kernel crashes.

Fixes: c5e29ea7ac ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200206062622.28235-1-oohall@gmail.com
2020-03-13 21:13:11 +11:00
John Hubbard
db0d32d840 cpufreq: powernv: fix stack bloat and hard limit on number of CPUs
The following build warning occurred on powerpc 64-bit builds:

drivers/cpufreq/powernv-cpufreq.c: In function 'init_chip_info':
drivers/cpufreq/powernv-cpufreq.c:1070:1: warning: the frame size of
1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]

This is with a cross-compiler based on gcc 8.1.0, which I got from:
  https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/

The warning is due to putting 1024 bytes on the stack:

    unsigned int chip[256];

...and it's also undesirable to have a hard limit on the number of
CPUs here.

Fix both problems by dynamically allocating based on num_possible_cpus,
as recommended by Michael Ellerman.

Fixes: 053819e0bf ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-04 11:47:47 +01:00
Thomas Gleixner
3e0a4e8580 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 118
Based on 1 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 as published by
  the free software foundation either version 2 or at your option any
  later version this program is distributed in the hope that it will
  be useful but without any warranty without even the implied warranty
  of merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 44 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190523091651.032047323@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:39:02 +02:00
Yangtao Li
5ae06c237f cpufreq: powernv: fix missing check of return value in init_powernv_pstates()
kmalloc() could fail, so insert a check of its return value. And
if it fails, returns -ENOMEM.

And remove (struct pstate_idx_revmap_data *) to fix coccinelle WARNING
by the way.

WARNING: casting value returned by memory allocation function to (struct
pstate_idx_revmap_data *) is useless.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-18 10:27:38 +05:30
Yangtao Li
3be466d681 cpufreq: powernv: add of_node_put()
The of_find_node_by_path() returns a node pointer with refcount
incremented,but there is the lack of use of the of_node_put() when
done.Add the missing of_node_put() to release the refcount.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-29 22:33:32 +01:00
Shilpasri G Bhat
dcb14337e0 cpufreq: powernv: Remove global pstate ramp-down timer in POWER9
POWER9 does not support global pstate requests for the chip. So remove
the timer logic which slowly ramps down the global pstate in P9
platforms.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[mpe: Drop NULL check before kfree(policy->driver_data)]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-09 18:06:02 +10:00
Shilpasri G Bhat
c0f7f5b6c6 cpufreq: powernv: Fix hardlockup due to synchronous smp_call in timer interrupt
gpstate_timer_handler() uses synchronous smp_call to set the pstate
on the requested core. This causes the below hard lockup:

  smp_call_function_single+0x110/0x180 (unreliable)
  smp_call_function_any+0x180/0x250
  gpstate_timer_handler+0x1e8/0x580
  call_timer_fn+0x50/0x1c0
  expire_timers+0x138/0x1f0
  run_timer_softirq+0x1e8/0x270
  __do_softirq+0x158/0x3e4
  irq_exit+0xe8/0x120
  timer_interrupt+0x9c/0xe0
  decrementer_common+0x114/0x120
  -- interrupt: 901 at doorbell_global_ipi+0x34/0x50
  LR = arch_send_call_function_ipi_mask+0x120/0x130
  arch_send_call_function_ipi_mask+0x4c/0x130
  smp_call_function_many+0x340/0x450
  pmdp_invalidate+0x98/0xe0
  change_huge_pmd+0xe0/0x270
  change_protection_range+0xb88/0xe40
  mprotect_fixup+0x140/0x340
  SyS_mprotect+0x1b4/0x350
  system_call+0x58/0x6c

One way to avoid this is removing the smp-call. We can ensure that the
timer always runs on one of the policy-cpus. If the timer gets
migrated to a cpu outside the policy then re-queue it back on the
policy->cpus. This way we can get rid of the smp-call which was being
used to set the pstate on the policy->cpus.

Fixes: 7bc54b652f ("timers, cpufreq/powernv: Initialize the gpstate timer as pinned")
Cc: stable@vger.kernel.org # v4.8+
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-27 16:16:10 +10:00
Viresh Kumar
bf14721c97 cpufreq: powernv: Don't validate the frequency table twice
The cpufreq core is already validating the CPU frequency table after
calling the ->init() callback of the cpufreq drivers and the drivers
don't need to do the same anymore. Though they need to set the
policy->freq_table field directly from the ->init() callback now.

Stop validating the frequency table from powernv driver.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-03-19 00:04:56 +01:00
Shilpasri G Bhat
3fa4680b86 cpufreq: powernv: Dont assume distinct pstate values for nominal and pmin
Some OpenPOWER boxes can have same pstate values for nominal and
pmin pstates. In these boxes the current code will not initialize
'powernv_pstate_info.min' variable and result in erroneous CPU
frequency reporting. This patch fixes this problem.

Fixes: 09ca4c9b59 (cpufreq: powernv: Replacing pstate_id with frequency table index)
Reported-by: Alvin Wang <wangat@tw.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-12 13:44:08 +01:00
Gautham R. Shenoy
967b87fd81 powernv-cpufreq: Treat pstates as opaque 8-bit values
On POWER8 and POWER9, the PMSR and the PMCR registers define pstates
to be 8-bit wide values. The device-tree exports pstates as 32-bit
wide values of which the lower byte is the actual pstate.

The current implementation in the kernel treats pstates as integer
type, since it used to use the sign of the pstate for performing some
boundary-checks. This is no longer required after the patch
"powernv-cpufreq: Fix pstate_to_idx() to handle non-continguous
pstates".

So, in this patch, we modify the powernv-cpufreq driver to uniformly
treat pstates as opaque 8-bit values obtained from the device-tree or
the PMCR. This simplifies the extract_pstate() helper function since
we no longer no longer require to worry about the sign-extentions.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-05 13:11:24 +01:00
Gautham R. Shenoy
332f0a01f0 powernv-cpufreq: Fix pstate_to_idx() to handle non-continguous pstates
The code in powernv-cpufreq, makes the following two assumptions which
are not guaranteed by the device-tree bindings:

    1) Pstate ids are continguous: This is used in pstate_to_idx() to
       obtain the reverse map from a pstate to it's corresponding
       entry into the cpufreq frequency table.

    2) Every Pstate should always lie between the max and the min
       pstates that are explicitly reported in the device tree: This
       is used to determine whether a pstate reported by the PMSR is
       out of bounds.

Both these assumptions are unwarranted and can change on future
platforms.

In this patch, we maintain the reverse map from a pstate to it's index
in the cpufreq frequency table and use this in pstate_to_idx(). This
does away with the assumptions (1) mentioned above, and will work with
non continguous pstate ids. If no entry exists for a particular
pstate, then such a pstate is treated as being out of bounds. This
gets rid of assumption (2).

On all the existing platforms, where the pstates are 8-bit long
values, the new implementation of pstate_to_idx() takes constant time.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-05 13:11:24 +01:00
Gautham R. Shenoy
ee1f4a7daf powernv-cpufreq: Add helper to extract pstate from PMSR
On POWERNV platform, the fields for pstates in the Power Management
Status Register (PMSR) and the Power Management Control Register
(PMCR) are 8-bits wide. On POWER8 the pstates are negatively numbered
while on POWER9 they are positively numbered.

The device-tree exports pstates as 32-bit entries. The device-tree
implementation sign-extends the 8-bit pstate values to obtain the
corresponding 32-bit entry.

Eg: On POWER8, a pstate value 0x82 [-126] is represented in the
device-tree as 0xfffffff82 while on POWER9, the same value 0x82 [130]
is represented in the device-tree as 0x00000082.

The powernv-cpufreq driver implementation represents pstates using the
integer type. In multiple places in the driver, the code interprets
the pstates extracted from the PMSR as a signed byte and assigns it to
a integer variable to get the sign-extention.

On POWER9 platforms which have greater than 128 pstates, this results
in the driver performing incorrect sign-extention, and thereby
treating a legitimate pstate (say 130) as an invalid pstates (since it
is interpreted as -126).

This patch fixes the issue by implementing a helper function to
extract Pstates from PMSR register, and correctly sign-extend it to be
consistent with the values provided by the device-tree.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-05 13:11:24 +01:00
Kees Cook
1d1fe902af timer: Remove init_timer_pinned_deferrable() in favor of timer_setup()
This refactors the only user of init_timer_pinned_deferrable() to use the
new timer_setup() and from_timer(). Adds a pointer back to the policy,
and drops the definition of init_timer_pinned_deferrable().

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: Petr Mladek <pmladek@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: linux1394-devel@lists.sourceforge.net
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: linux-s390@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ursula Braun <ubraun@linux.vnet.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Harish Patil <harish.patil@cavium.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Manish Chopra <manish.chopra@cavium.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-pm@vger.kernel.org
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mark Gross <mark.gross@intel.com>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Michael Reed <mdr@sgi.com>
Cc: netdev@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lkml.kernel.org/r/1507159627-127660-3-git-send-email-keescook@chromium.org
2017-10-05 15:01:16 +02:00
Shilpasri G Bhat
b12f7a2b01 cpufreq: powernv: Add boost files to export ultra-turbo frequencies
In P8+, Workload Optimized Frequency(WOF) provides the capability to
boost the cpu frequency based on the utilization of the other cpus
running in the chip. The On-Chip-Controller(OCC) firmware will control
the achievability of these frequencies depending on the power headroom
available in the chip. Currently the ultra-turbo frequencies provided
by this feature are exported along with the turbo and sub-turbo
frequencies as scaling_available_frequencies. This patch will export
the ultra-turbo frequencies separately as scaling_boost_frequencies in
WOF enabled systems. This patch will add the boost sysfs file which
can be used to disable/enable ultra-turbo frequencies.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-03 23:59:41 +01:00
Denis Kirjanov
8a10c06a20 cpufreq: powernv: Disable preemption while checking CPU throttling state
With preemption turned on we can read incorrect throttling state
while being switched to CPU on a different chip.

 BUG: using smp_processor_id() in preemptible [00000000] code: cat/7343
 caller is .powernv_cpufreq_throttle_check+0x2c/0x710
 CPU: 13 PID: 7343 Comm: cat Not tainted 4.8.0-rc5-dirty #1
 Call Trace:
 [c0000007d25b75b0] [c000000000971378] .dump_stack+0xe4/0x150 (unreliable)
 [c0000007d25b7640] [c0000000005162e4] .check_preemption_disabled+0x134/0x150
 [c0000007d25b76e0] [c0000000007b63ac] .powernv_cpufreq_throttle_check+0x2c/0x710
 [c0000007d25b7790] [c0000000007b6d18] .powernv_cpufreq_target_index+0x288/0x360
 [c0000007d25b7870] [c0000000007acee4] .__cpufreq_driver_target+0x394/0x8c0
 [c0000007d25b7920] [c0000000007b22ac] .cpufreq_set+0x7c/0xd0
 [c0000007d25b79b0] [c0000000007adf50] .store_scaling_setspeed+0x80/0xc0
 [c0000007d25b7a40] [c0000000007ae270] .store+0xa0/0x100
 [c0000007d25b7ae0] [c0000000003566e8] .sysfs_kf_write+0x88/0xb0
 [c0000007d25b7b70] [c0000000003553b8] .kernfs_fop_write+0x178/0x260
 [c0000007d25b7c10] [c0000000002ac3cc] .__vfs_write+0x3c/0x1c0
 [c0000007d25b7cf0] [c0000000002ad584] .vfs_write+0xc4/0x230
 [c0000007d25b7d90] [c0000000002aeef8] .SyS_write+0x58/0x100
 [c0000007d25b7e30] [c00000000000bfec] system_call+0x38/0xfc

Fixes: 09a972d162 (cpufreq: powernv: Report cpu frequency throttling)
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 23:29:59 +01:00
Akshay Adiga
c9a81e6864 cpufreq: powernv: Fix uninitialized lpstate_idx in gpstates_timer_handler()
lpstate_idx remains uninitialized in the case when elapsed_time
is greater than MAX_RAMP_DOWN_TIME.  At the end of rampdown the
global pstate should be equal to the local pstate.

Fixes: 20b15b7663 (cpufreq: powernv: Use PMCR to verify global and localpstate)
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 21:32:31 +01:00
Akshay Adiga
20b15b7663 cpufreq: powernv: Use PMCR to verify global and local pstate
As fast_switch() may get called with interrupt disable mode, we cannot
hold a mutex to update the global_pstate_info. So currently, fast_switch()
does not update the global_pstate_info and it will end up with stale data
whenever pstate is updated through fast_switch().

As the gpstate_timer can fire after fast_switch() has updated the pstates,
the timer handler cannot rely on the cached values of local and global
pstate and needs to read it from the PMCR.

Only gpstate_timer_handler() is affected by the stale cached pstate data
beacause either fast_switch() or target_index() routines will be called
for a given govenor, but gpstate_timer can fire after the governor has
changed to schedutil.

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-11 01:41:02 +01:00
Akshay Adiga
60c9efb8f7 cpufreq: powernv: Adding fast_switch for schedutil
Adding fast_switch which does light weight operation to set the desired
pstate. Both global and local pstates are set to the same desired pstate.

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-11 01:41:02 +01:00
Rafael J. Wysocki
0aeeb3e73f Merge branches 'pm-sleep' and 'pm-cpufreq'
* pm-sleep:
  PM / hibernate: Restore processor state before using per-CPU variables
  x86/power/64: Always create temporary identity mapping correctly

* pm-cpufreq:
  cpufreq: powernv: Fix crash in gpstate_timer_handler()
2016-08-12 22:53:58 +02:00
Akshay Adiga
8e85946777 cpufreq: powernv: Fix crash in gpstate_timer_handler()
Commit 09ca4c9b59 (cpufreq: powernv: Replacing pstate_id with
frequency table index) changes calc_global_pstate() to use
cpufreq_table index instead of pstate_id.

But in gpstate_timer_handler(), pstate_id was being passed instead
of cpufreq_table index, which caused index_to_pstate() to access
out of bound indices, leading to this crash.

Adding sanity check for index and pstate, to ensure only valid pstate
and index values are returned.

Call Trace:
[c00000078d66b130] [c00000000011d224] __free_irq+0x234/0x360
(unreliable)
[c00000078d66b1c0] [c00000000011d44c] free_irq+0x6c/0xa0
[c00000078d66b1f0] [c00000000006c4f8] opal_event_shutdown+0x88/0xd0
[c00000078d66b230] [c000000000067a4c] opal_shutdown+0x1c/0x90
[c00000078d66b260] [c000000000063a00] pnv_shutdown+0x20/0x40
[c00000078d66b280] [c000000000021538] machine_restart+0x38/0x90
[c0000000078d66b310] [c000000000965ea0] panic+0x284/0x300
[c00000078d66b3a0] [c00000000001f508] die+0x388/0x450
[c00000078d66b430] [c000000000045a50] bad_page_fault+0xd0/0x140
[c00000078d66b4a0] [c000000000008964] handle_page_fault+0x2c/0x30
   interrupt: 300 at gpstate_timer_handler+0x150/0x260
    LR = gpstate_timer_handler+0x130/0x260
[c00000078d66b7f0] [c000000000132b58] call_timer_fn+0x58/0x1c0
[c00000078d66b880] [c000000000132e20] expire_timers+0x130/0x1d0
[c00000078d66b8f0] [c000000000133068] run_timer_softirq+0x1a8/0x230
[c00000078d66b980] [c0000000000b535c] __do_softirq+0x18c/0x400
[c00000078d66ba70] [c0000000000b5828] irq_exit+0xc8/0x100
[c00000078d66ba90] [c00000000001e214] timer_interrupt+0xa4/0xe0
[c00000078d66bac0] [c0000000000027d0] decrementer_common+0x150/0x180
   interrupt: 901 at arch_local_irq_restore+0x74/0x90
  0] [c000000000106b34] call_cpuidle+0x44/0x90
[c00000078d66be50] [c00000000010708c] cpu_startup_entry+0x38c/0x460
[c00000078d66bf20] [c00000000003d930] start_secondary+0x330/0x380
[c00000078d66bf90] [c000000000008e6c] start_secondary_prolog+0x10/0x14

Fixes: 09ca4c9b59 (cpufreq: powernv: Replacing pstate_id with frequency table index)
Reported-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-06 14:52:26 +02:00
Linus Torvalds
6453dbdda3 Power management material for v4.8-rc1
- Rework the cpufreq governor interface to make it more straightforward
    and modify the conservative governor to avoid using transition
    notifications (Rafael Wysocki).
 
  - Rework the handling of frequency tables by the cpufreq core to make
    it more efficient (Viresh Kumar).
 
  - Modify the schedutil governor to reduce the number of wakeups it
    causes to occur in cases when the CPU frequency doesn't need to be
    changed (Steve Muckle, Viresh Kumar).
 
  - Fix some minor issues and clean up code in the cpufreq core and
    governors (Rafael Wysocki, Viresh Kumar).
 
  - Add Intel Broxton support to the intel_pstate driver (Srinivas
    Pandruvada).
 
  - Fix problems related to the config TDP feature and to the validity
    of the MSR_HWP_INTERRUPT register in intel_pstate (Jan Kiszka,
    Srinivas Pandruvada).
 
  - Make intel_pstate update the cpu_frequency tracepoint even if
    the frequency doesn't change to avoid confusing powertop (Rafael
    Wysocki).
 
  - Clean up the usage of __init/__initdata in intel_pstate, mark some
    of its internal variables as __read_mostly and drop an unused
    structure element from it (Jisheng Zhang, Carsten Emde).
 
  - Clean up the usage of some duplicate MSR symbols in intel_pstate
    and turbostat (Srinivas Pandruvada).
 
  - Update/fix the powernv, s3c24xx and mvebu cpufreq drivers (Akshay
    Adiga, Viresh Kumar, Ben Dooks).
 
  - Fix a regression (introduced during the 4.5 cycle) in the
    pcc-cpufreq driver by reverting the problematic commit (Andreas
    Herrmann).
 
  - Add support for Intel Denverton to intel_idle, clean up Broxton
    support in it and make it explicitly non-modular (Jacob Pan,
    Jan Beulich, Paul Gortmaker).
 
  - Add support for Denverton and Ivy Bridge server to the Intel RAPL
    power capping driver and make it more careful about the handing
    of MSRs that may not be present (Jacob Pan, Xiaolong Wang).
 
  - Fix resume from hibernation on x86-64 by making the CPU offline
    during resume avoid using MONITOR/MWAIT in the "play dead" loop
    which may lead to an inadvertent "revival" of a "dead" CPU and
    a page fault leading to a kernel crash from it (Rafael Wysocki).
 
  - Make memory management during resume from hibernation more
    straightforward (Rafael Wysocki).
 
  - Add debug features that should help to detect problems related
    to hibernation and resume from it (Rafael Wysocki, Chen Yu).
 
  - Clean up hibernation core somewhat (Rafael Wysocki).
 
  - Prevent KASAN from instrumenting the hibernation core which leads
    to large numbers of false-positives from it (James Morse).
 
  - Prevent PM (hibernate and suspend) notifiers from being called
    during the cleanup phase if they have not been called during the
    corresponding preparation phase which is possible if one of the
    other notifiers returns an error at that time (Lianwei Wang).
 
  - Improve suspend-related debug printout in the tasks freezer and
    clean up suspend-related console handling (Roger Lu, Borislav
    Petkov).
 
  - Update the AnalyzeSuspend script in the kernel sources to
    version 4.2 (Todd Brandt).
 
  - Modify the generic power domains framework to make it handle
    system suspend/resume better (Ulf Hansson).
 
  - Make the runtime PM framework avoid resuming devices synchronously
    when user space changes the runtime PM settings for them and
    improve its error reporting (Rafael Wysocki, Linus Walleij).
 
  - Fix error paths in devfreq drivers (exynos, exynos-ppmu, exynos-bus)
    and in the core, make some devfreq code explicitly non-modular and
    change some of it into tristate (Bartlomiej Zolnierkiewicz,
    Peter Chen, Paul Gortmaker).
 
  - Add DT support to the generic PM clocks management code and make
    it export some more symbols (Jon Hunter, Paul Gortmaker).
 
  - Make the PCI PM core code slightly more robust against possible
    driver errors (Andy Shevchenko).
 
  - Make it possible to change DESTDIR and PREFIX in turbostat
    (Andy Shevchenko).
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Merge tag 'pm-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael  Wysocki:
 "Again, the majority of changes go into the cpufreq subsystem, but
  there are no big features this time.  The cpufreq changes that stand
  out somewhat are the governor interface rework and improvements
  related to the handling of frequency tables.  Apart from those, there
  are fixes and new device/CPU IDs in drivers, cleanups and an
  improvement of the new schedutil governor.

  Next, there are some changes in the hibernation core, including a fix
  for a nasty problem related to the MONITOR/MWAIT usage by CPU offline
  during resume from hibernation, a few core improvements related to
  memory management during resume, a couple of additional debug features
  and cleanups.

  Finally, we have some fixes and cleanups in the devfreq subsystem,
  generic power domains framework improvements related to system
  suspend/resume, support for some new chips in intel_idle and in the
  power capping RAPL driver, a new version of the AnalyzeSuspend utility
  and some assorted fixes and cleanups.

  Specifics:

   - Rework the cpufreq governor interface to make it more
     straightforward and modify the conservative governor to avoid using
     transition notifications (Rafael Wysocki).

   - Rework the handling of frequency tables by the cpufreq core to make
     it more efficient (Viresh Kumar).

   - Modify the schedutil governor to reduce the number of wakeups it
     causes to occur in cases when the CPU frequency doesn't need to be
     changed (Steve Muckle, Viresh Kumar).

   - Fix some minor issues and clean up code in the cpufreq core and
     governors (Rafael Wysocki, Viresh Kumar).

   - Add Intel Broxton support to the intel_pstate driver (Srinivas
     Pandruvada).

   - Fix problems related to the config TDP feature and to the validity
     of the MSR_HWP_INTERRUPT register in intel_pstate (Jan Kiszka,
     Srinivas Pandruvada).

   - Make intel_pstate update the cpu_frequency tracepoint even if the
     frequency doesn't change to avoid confusing powertop (Rafael
     Wysocki).

   - Clean up the usage of __init/__initdata in intel_pstate, mark some
     of its internal variables as __read_mostly and drop an unused
     structure element from it (Jisheng Zhang, Carsten Emde).

   - Clean up the usage of some duplicate MSR symbols in intel_pstate
     and turbostat (Srinivas Pandruvada).

   - Update/fix the powernv, s3c24xx and mvebu cpufreq drivers (Akshay
     Adiga, Viresh Kumar, Ben Dooks).

   - Fix a regression (introduced during the 4.5 cycle) in the
     pcc-cpufreq driver by reverting the problematic commit (Andreas
     Herrmann).

   - Add support for Intel Denverton to intel_idle, clean up Broxton
     support in it and make it explicitly non-modular (Jacob Pan, Jan
     Beulich, Paul Gortmaker).

   - Add support for Denverton and Ivy Bridge server to the Intel RAPL
     power capping driver and make it more careful about the handing of
     MSRs that may not be present (Jacob Pan, Xiaolong Wang).

   - Fix resume from hibernation on x86-64 by making the CPU offline
     during resume avoid using MONITOR/MWAIT in the "play dead" loop
     which may lead to an inadvertent "revival" of a "dead" CPU and a
     page fault leading to a kernel crash from it (Rafael Wysocki).

   - Make memory management during resume from hibernation more
     straightforward (Rafael Wysocki).

   - Add debug features that should help to detect problems related to
     hibernation and resume from it (Rafael Wysocki, Chen Yu).

   - Clean up hibernation core somewhat (Rafael Wysocki).

   - Prevent KASAN from instrumenting the hibernation core which leads
     to large numbers of false-positives from it (James Morse).

   - Prevent PM (hibernate and suspend) notifiers from being called
     during the cleanup phase if they have not been called during the
     corresponding preparation phase which is possible if one of the
     other notifiers returns an error at that time (Lianwei Wang).

   - Improve suspend-related debug printout in the tasks freezer and
     clean up suspend-related console handling (Roger Lu, Borislav
     Petkov).

   - Update the AnalyzeSuspend script in the kernel sources to version
     4.2 (Todd Brandt).

   - Modify the generic power domains framework to make it handle system
     suspend/resume better (Ulf Hansson).

   - Make the runtime PM framework avoid resuming devices synchronously
     when user space changes the runtime PM settings for them and
     improve its error reporting (Rafael Wysocki, Linus Walleij).

   - Fix error paths in devfreq drivers (exynos, exynos-ppmu,
     exynos-bus) and in the core, make some devfreq code explicitly
     non-modular and change some of it into tristate (Bartlomiej
     Zolnierkiewicz, Peter Chen, Paul Gortmaker).

   - Add DT support to the generic PM clocks management code and make it
     export some more symbols (Jon Hunter, Paul Gortmaker).

   - Make the PCI PM core code slightly more robust against possible
     driver errors (Andy Shevchenko).

   - Make it possible to change DESTDIR and PREFIX in turbostat (Andy
     Shevchenko)"

* tag 'pm-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (89 commits)
  Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency"
  PM / hibernate: Introduce test_resume mode for hibernation
  cpufreq: export cpufreq_driver_resolve_freq()
  cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index()
  PCI / PM: check all fields in pci_set_platform_pm()
  cpufreq: acpi-cpufreq: use cached frequency mapping when possible
  cpufreq: schedutil: map raw required frequency to driver frequency
  cpufreq: add cpufreq_driver_resolve_freq()
  cpufreq: intel_pstate: Check cpuid for MSR_HWP_INTERRUPT
  intel_pstate: Update cpu_frequency tracepoint every time
  cpufreq: intel_pstate: clean remnant struct element
  PM / tools: scripts: AnalyzeSuspend v4.2
  x86 / hibernate: Use hlt_play_dead() when resuming from hibernation
  cpufreq: powernv: Replacing pstate_id with frequency table index
  intel_pstate: Fix MSR_CONFIG_TDP_x addressing in core_get_max_pstate()
  PM / hibernate: Image data protection during restoration
  PM / hibernate: Add missing braces in __register_nosave_region()
  PM / hibernate: Clean up comments in snapshot.c
  PM / hibernate: Clean up function headers in snapshot.c
  PM / hibernate: Add missing braces in hibernate_setup()
  ...
2016-07-26 17:29:07 -07:00
Akshay Adiga
09ca4c9b59 cpufreq: powernv: Replacing pstate_id with frequency table index
Refactoring code to use frequency table index instead of pstate_id.
This abstraction will make the code independent of the pstate values.

- No functional changes
- The highest frequency is at frequency table index 0 and the frequency
  decreases as the index increases.
- Macros pstates_to_idx() and idx_to_pstate() can be used for conversion
  between pstate_id and index.
- powernv_pstate_info now contains frequency table index to min, max and
  nominal frequency (instead of pstate_ids)
- global_pstate_info new stores index values instead pstate ids.
- variables renamed as *_idx which now store index instead of pstate

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-12 02:47:10 +02:00
Thomas Gleixner
7bc54b652f timers, cpufreq/powernv: Initialize the gpstate timer as pinned
Pinned timers must carry the pinned attribute in the timer structure
itself, so convert the code to the new API.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.297014487@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-07 10:25:14 +02:00
Viresh Kumar
825773609c cpufreq: Reuse new freq-table helpers
This patch migrates few users of cpufreq tables to the new helpers
that work on sorted freq-tables.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-07 00:14:27 +02:00
Viresh Kumar
d218ed7739 cpufreq: Return index from cpufreq_frequency_table_target()
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 <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09 00:58:06 +02:00
Viresh Kumar
7ab4aabbaa cpufreq: Drop freq-table param to cpufreq_frequency_table_target()
The policy already has this pointer set, use it instead.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09 00:58:06 +02:00
Akshay Adiga
0bc10b93f2 cpufreq: powernv: del_timer_sync when global and local pstate are equal
When global and local pstate are equal in a powernv_target_index() call,
we don't queue a timer. But we may have timer already queued for future.
This could cause the timer to fire one additional time for no use.

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-11 02:28:00 +02:00
Akshay Adiga
1fd3ff2874 cpufreq: powernv: Move smp_call_function_any() out of irq safe block
Fix a WARN_ON caused by smp_call_function_any() when irq is disabled,
because of changes made in the patch ('cpufreq: powernv: Ramp-down
 global pstate slower than local-pstate')
https://patchwork.ozlabs.org/patch/612058/

 WARNING: CPU: 0 PID: 4 at kernel/smp.c:291
smp_call_function_single+0x170/0x180

 Call Trace:
 [c0000007f648f9f0] [c0000007f648fa90] 0xc0000007f648fa90 (unreliable)
 [c0000007f648fa30] [c0000000001430e0] smp_call_function_any+0x170/0x1c0
 [c0000007f648fa90] [c0000000007b4b00]
powernv_cpufreq_target_index+0xe0/0x250
 [c0000007f648fb00] [c0000000007ac9dc]
__cpufreq_driver_target+0x20c/0x3d0
 [c0000007f648fbc0] [c0000000007b1b4c] od_dbs_timer+0xcc/0x260
 [c0000007f648fc10] [c0000000007b3024] dbs_work_handler+0x54/0xa0
 [c0000007f648fc50] [c0000000000c49a8] process_one_work+0x1d8/0x590
 [c0000007f648fce0] [c0000000000c4e08] worker_thread+0xa8/0x660
 [c0000007f648fd80] [c0000000000cca88] kthread+0x108/0x130
 [c0000007f648fe30] [c0000000000095e8] ret_from_kernel_thread+0x5c/0x74

- Calling smp_call_function_any() with interrupt disabled (through
 spin_lock_irqsave) could cause a deadlock, as smp_call_function_any()
 relies on the IPI to complete. This is detected in the
 smp_call_function_any() call and hence the WARN_ON.

- As the spinlock (gpstates->lock) is only used to synchronize access of
 global_pstate_info  between timer irq handler and target_index calls. And
 the timer irq handler just try_locks() hence it would not cause a
 deadlock. Hence could do without making spinlocks irq safe.

- As the smp_call_function_any() is a blocking call and does not access
 global_pstates_info, it could reduce the critcal section by moving
 smp_call_function_any() after giving up the lock.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.linux.com>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-11 02:28:00 +02:00
Akshay Adiga
eaa2c3aeef cpufreq: powernv: Ramp-down global pstate slower than local-pstate
The frequency transition latency from pmin to pmax is observed to be in
few millisecond granurality. And it usually happens to take a performance
penalty during sudden frequency rampup requests.

This patch set solves this problem by using an entity called "global
pstates". The global pstate is a Chip-level entity, so the global entitiy
(Voltage) is managed across the cores. The local pstate is a Core-level
entity, so the local entity (frequency) is managed across threads.

This patch brings down global pstate at a slower rate than the local
pstate. Hence by holding global pstates higher than local pstate makes
the subsequent rampups faster.

A per policy structure is maintained to keep track of the global and
local pstate changes. The global pstate is brought down using a parabolic
equation. The ramp down time to pmin is set to ~5 seconds. To make sure
that the global pstates are dropped at regular interval , a timer is
queued for every 2 seconds during ramp-down phase, which eventually brings
the pstate down to local pstate.

Iozone results show fairly consistent performance boost.
YCSB on redis shows improved Max latencies in most cases.

Iozone write/rewite test were made with filesizes 200704Kb and 401408Kb
with different record sizes . The following table shows IOoperations/sec
with and without patch.

Iozone Results ( in op/sec) ( mean over 3 iterations )
---------------------------------------------------------------------
file size-                      with            without		  %
recordsize-IOtype               patch           patch		change
----------------------------------------------------------------------
200704-1-SeqWrite               1616532         1615425         0.06
200704-1-Rewrite                2423195         2303130         5.21
200704-2-SeqWrite               1628577         1602620         1.61
200704-2-Rewrite                2428264         2312154         5.02
200704-4-SeqWrite               1617605         1617182         0.02
200704-4-Rewrite                2430524         2351238         3.37
200704-8-SeqWrite               1629478         1600436         1.81
200704-8-Rewrite                2415308         2298136         5.09
200704-16-SeqWrite              1619632         1618250         0.08
200704-16-Rewrite               2396650         2352591         1.87
200704-32-SeqWrite              1632544         1598083         2.15
200704-32-Rewrite               2425119         2329743         4.09
200704-64-SeqWrite              1617812         1617235         0.03
200704-64-Rewrite               2402021         2321080         3.48
200704-128-SeqWrite             1631998         1600256         1.98
200704-128-Rewrite              2422389         2304954         5.09
200704-256 SeqWrite             1617065         1616962         0.00
200704-256-Rewrite              2432539         2301980         5.67
200704-512-SeqWrite             1632599         1598656         2.12
200704-512-Rewrite              2429270         2323676         4.54
200704-1024-SeqWrite            1618758         1616156         0.16
200704-1024-Rewrite             2431631         2315889         4.99
401408-1-SeqWrite               1631479         1608132         1.45
401408-1-Rewrite                2501550         2459409         1.71
401408-2-SeqWrite               1617095         1626069         -0.55
401408-2-Rewrite                2507557         2443621         2.61
401408-4-SeqWrite               1629601         1611869         1.10
401408-4-Rewrite                2505909         2462098         1.77
401408-8-SeqWrite               1617110         1626968         -0.60
401408-8-Rewrite                2512244         2456827         2.25
401408-16-SeqWrite              1632609         1609603         1.42
401408-16-Rewrite               2500792         2451405         2.01
401408-32-SeqWrite              1619294         1628167         -0.54
401408-32-Rewrite               2510115         2451292         2.39
401408-64-SeqWrite              1632709         1603746         1.80
401408-64-Rewrite               2506692         2433186         3.02
401408-128-SeqWrite             1619284         1627461         -0.50
401408-128-Rewrite              2518698         2453361         2.66
401408-256-SeqWrite             1634022         1610681         1.44
401408-256-Rewrite              2509987         2446328         2.60
401408-512-SeqWrite             1617524         1628016         -0.64
401408-512-Rewrite              2504409         2442899         2.51
401408-1024-SeqWrite            1629812         1611566         1.13
401408-1024-Rewrite             2507620          2442968        2.64

Tested with YCSB workload (50% update + 50% read) over redis for 1 million
records and 1 million operation. Each test was carried out with target
operations per second and persistence disabled.

Max-latency (in us)( mean over 5 iterations )
---------------------------------------------------------------
op/s    Operation       with patch      without patch   %change
---------------------------------------------------------------
15000   Read            61480.6         50261.4         22.32
15000   cleanup         215.2           293.6           -26.70
15000   update          25666.2         25163.8         2.00

25000   Read            32626.2         89525.4         -63.56
25000   cleanup         292.2           263.0           11.10
25000   update          32293.4         90255.0         -64.22

35000   Read            34783.0         33119.0         5.02
35000   cleanup         321.2           395.8           -18.8
35000   update          36047.0         38747.8         -6.97

40000   Read            38562.2         42357.4         -8.96
40000   cleanup         371.8           384.6           -3.33
40000   update          27861.4         41547.8         -32.94

45000   Read            42271.0         88120.6         -52.03
45000   cleanup         263.6           383.0           -31.17
45000   update          29755.8         81359.0         -63.43

(test without target op/s)
47659   Read            83061.4         136440.6        -39.12
47659   cleanup         195.8           193.8           1.03
47659   update          73429.4         124971.8        -41.24

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-27 23:56:58 +02:00
Shilpasri G Bhat
2920e9ce8f cpufreq: powernv: Remove flag use-case of policy->driver_data
commit 1b0289848d ("cpufreq: powernv: Add sysfs attributes to show
throttle stats") used policy->driver_data as a flag for one-time creation
of throttle sysfs files. Instead of this use 'kernfs_find_and_get()' to
check if the attribute already exists. This is required as
policy->driver_data is used for other purposes in the later patch.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-27 23:56:58 +02:00
Shilpasri G Bhat
1b0289848d cpufreq: powernv: Add sysfs attributes to show throttle stats
Create sysfs attributes to export throttle information in
/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory. The
newly added sysfs files are as follows:

 1)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat
 2)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub-turbo_stat
 3)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle
 4)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap
 5)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp
 6)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault
 7)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent
 8)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset

Detailed explanation of each attribute is added to
Documentation/ABI/testing/sysfs-devices-system-cpu

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 23:11:18 +01:00
Michael Neuling
3e5963bc34 cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
Commit 96c4726f01 "cpufreq: powernv: Remove cpu_to_chip_id() from
hot-path" introduced a 'core_to_chip_map' array to cache the chip-ids
of all cores.

Replace this with a per-CPU variable that stores the pointer to the
chip-array. This removes the linear lookup and provides a neater and
simpler solution.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 01:08:55 +01:00
Shilpasri G Bhat
c5e29ea7ac cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}
Unregister the notifiers if cpufreq_driver_register() fails in
powernv_cpufreq_init(). Re-arrange the unregistration and cleanup routines
in powernv_cpufreq_exit() to free all the resources after the driver
has unregistered.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26 22:18:19 +01:00
Shilpasri G Bhat
c89f2682a3 cpufreq: powernv: Replace pr_info with trace print for throttle event
Currently we use printk message to notify the throttle event. But this
can flood the console if the cpu is throttled frequently. So replace the
printk with the tracepoint to notify the throttle event. And also events
like throttle below nominal frequency and OCC_RESET are reduced to
pr_warn/pr_warn_once as pointed by MFG to not mark them as critical
messages. This patch adds 'throttle_reason' to struct chip to store the
throttle reason.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:03 +01:00
Shilpasri G Bhat
96c4726f01 cpufreq: powernv: Remove cpu_to_chip_id() from hot-path
cpu_to_chip_id() does a DT walk through to find out the chip id by
taking a contended device tree lock. This adds an unnecessary overhead
in a hot path. So instead of calling cpu_to_chip_id() everytime cache
the chip ids for all cores in the array 'core_to_chip_map' and use it
in the hotpath.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:02 +01:00
Shilpasri G Bhat
6d167a44e6 cpufreq: powernv: Hot-plug safe the kworker thread
In the kworker_thread powernv_cpufreq_work_fn(), we can end up
sending an IPI to a cpu going offline. This is a rare corner case
which is fixed using {get/put}_online_cpus(). Along with this fix,
this patch adds changes to do oneshot cpumask_{clear/and} operation.

Suggested-by: Shreyas B Prabhu <shreyas@linux.vnet.ibm.com>
Suggested-by: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:02 +01:00
Shilpasri G Bhat
86622cb8c5 cpufreq: powernv: Free 'chips' on module exit
This will free the dynamically allocated memory of 'chips' on
module exit.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:01 +01:00
Stewart Smith
e4d54f71d2 powerpc/powernv: remove FW_FEATURE_OPALv3 and just use FW_FEATURE_OPAL
Long ago, only in the lab, there was OPALv1 and OPALv2. Now there is
just OPALv3, with nobody ever expecting anything on pre-OPALv3 to
be cared about or supported by mainline kernels.

So, let's remove FW_FEATURE_OPALv3 and instead use FW_FEATURE_OPAL
exclusively.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:54 +11:00
Shilpasri G Bhat
d43b1b6f8e cpufreq : powernv: Report Pmax throttling if capped below nominal frequency
Log a 'critical' message if the max frequency is reduced below nominal
frequency. We already log 'info' message if the max frequency is
capped below turbo frequency. CPU should guarantee atleast nominal
frequency, but not turbo frequency in all system configurations and
environments. So report the pmax throttling with severity when Pmax is
dipped below nominal frequency.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-26 03:03:06 +02:00
Shilpasri G Bhat
309d0631cc cpufreq: powernv: Increase the verbosity of OCC console messages
Modify the OCC reset/load/active event message to make it clearer for
the user to understand the event and effect of the event.

Suggested-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01 15:51:25 +02:00
Shilpasri G Bhat
227942809b cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling
If frequency is throttled due to OCC reset then cpus will be in Psafe
frequency, so restore the frequency on all cpus to policy->cur when
OCCs are active again. And if frequency is throttled due to Pmax
capping then restore the frequency of all the cpus  in the chip on
unthrottling.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-28 17:24:14 +02:00
Shilpasri G Bhat
3dd3ebe5bb cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set
On a reset cycle of OCC, although the system retires from safe
frequency state the local pstate is not restored to Pmin or last
requested pstate. Now if the cpufreq governor initiates a pstate
change, the local pstate will be in Psafe and we will be reporting a
false positive when we are not throttled.

So in powernv_cpufreq_throttle_check() remove the condition which
checks if local pstate is less than Pmin while checking for Psafe
frequency. If the cpus are forced to Psafe then PMSR.psafe_mode_active
bit will be set. So, when OCCs become active this bit will be cleared.
Let us just rely on this bit for reporting throttling.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-28 17:24:14 +02:00
Shilpasri G Bhat
735366fc40 cpufreq: powernv: Call throttle_check() on receiving OCC_THROTTLE
Re-evaluate the chip's throttled state on recieving OCC_THROTTLE
notification by executing *throttle_check() on any one of the cpu on
the chip. This is a sanity check to verify if we were indeed
throttled/unthrottled after receiving OCC_THROTTLE notification.

We cannot call *throttle_check() directly from the notification
handler because we could be handling chip1's notification in chip2. So
initiate an smp_call to execute *throttle_check(). We are irq-disabled
in the notification handler, so use a worker thread to smp_call
throttle_check() on any of the cpu in the chipmask.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-28 17:24:13 +02:00
Shilpasri G Bhat
cb166fa937 cpufreq: powernv: Register for OCC related opal_message notification
OCC is an On-Chip-Controller which takes care of power and thermal
safety of the chip. During runtime due to power failure or
overtemperature the OCC may throttle the frequencies of the CPUs to
remain within the power budget.

We want the cpufreq driver to be aware of such situations to be able
to report the reason to the user. We register to opal_message_notifier
to receive OCC messages from opal.

powernv_cpufreq_throttle_check() reports any frequency throttling and
this patch will report the reason or event that caused throttling. We
can be throttled if OCC is reset or OCC limits Pmax due to power or
thermal reasons. We are also notified of unthrottling after an OCC
reset or if OCC restores Pmax on the chip.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-28 17:24:13 +02:00