per_cpu(processors, n) can be NULL, resulting in:

  Loading CPUFreq modules[  437.661360] BUG: unable to handle kernel NULL pointer dereference at (null)
  IP: [<ffffffffa0434314>] pcc_cpufreq_cpu_init+0x74/0x220 [pcc_cpufreq]

It's better to avoid the oops by failing the driver, and allowing the
system to boot.
Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add simple cpufreq driver for Maple-based boards (ppc970fx evaluation
kit and others). Driver is based on a cpufreq driver for 64-bit powermac
boxes with all pmac-dependant features removed and simple cleanup
applied.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The following symbols are needlessly defined global:
  s5pv210_verify_speed
  s5pv210_getspeed

Make them static.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

The following symbols are needlessly defined global:
  exynos4_verify_speed
  exynos4_getspeed
  exynos4_set_clkdiv

Make them static.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

By extension from the 667MHz based clocks currently supported add 100MHz
and 200MHz operating points. Due to a lack of documentation these have not
been confirmed as supported but by extension from the existing frequencies
they should be OK, and I've given them quite a bit of runtime testing.

The major risk is synchronization with the non-ARM clocks but as we
can't currently scale the ARM PLL the risk should be relatively low.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

When system reboot, the CPUFREQ level should be 800MHz to prevent
system lockup.
Signed-off-by: NHuisung Kang <hs1218.kang@samsung.com>
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Voltage scaling accesses the MAX8998 regulators over bit-banged I2C
with lots of udelays.  In the case of decreasing CPU speed, the
number of loops per us for udelay needs to be adjusted prior to
decreasing voltage to avoid delaying for up to 10X too long.
Signed-off-by: NTodd Poynor <toddpoynor@google.com>
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Without this lock the call to change the frequency for suspend could
switch to a new frequency while another thread was still changing the
cpu voltage.
Signed-off-by: NArve Hjønnevåg <arve@android.com>
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Minimum 800MHz is needed to enter/exit suspend mode due to voltage mismatch.
Signed-off-by: NHuisung Kang <hs1218.kang@samsung.com>
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Relation has an additional symantics other than standard.
s5pv310_target funtion have below additional relation.
- DISABLE_FURTHER_CPUFREQ : disable further access to target
- ENABLE_FURTHER_CPUFRER : enable access to target
Signed-off-by: NHuisung Kang <hs1218.kang@samsung.com>
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

The CPUFREQ_POSTCHANGE notification is used to update things that depend on
the system clock rates. Since this may include the interfaces used to talk
to the regulators do the notification before we try to update regulators
to reflect lowered system clock rate.

The voltage scaling is just a power optimisation and may not happen at all
so there's no concern about it not having completed.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

At least some newer S3C6410 silicon supports operation up to 800MHz rather
than just 667MHz. Unfortunately I don't have access to any of documentation
of this other than some running systems, add a new cpufreq table entry for
this based on the behaviour of those systems.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

The successive calls to clk_get each call clk_put in the case of failure,
but this is not done for subsequent error handling code.  The calls to
clk_get are moved to the end of the function, and appropriate gotos are
added.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression e1,e2;
statement S;
@@

e1 = clk_get@p1(...);
... when != e1 = e2
    when != clk_put(e1)
    when any
if (...) { ... when != clk_put(e1)
               when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
 } else S
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

According to discussion of the ARM arch subsystem migration,
ARM cpufreq drivers move to drivers/cpufreq. So this patch
adds Kconfig.arm for ARM like x86 and adds Samsung S5PV210
and EXYNOS4210 cpufreq driver compile in there.
As a note, otherw will be moved.

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

This is a straight code motion patch, there are no changes to the driver
itself. The Kconfig is left untouched as the ARM CPUfreq Kconfig is all
in one big block in arm/Kconfig and should be moved en masse rather than
being done piecemeal.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NDave Jones <davej@redhat.com>

acpi-cpufreq checks each CPU for aperf/mperf support, but only sets a
global flag. This will cause errors if some CPUs in the system don't
support the feature. Check boot_cpu_has() instead in order to make sure
that all CPUs support it.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NDave Jones <davej@redhat.com>

I came across a memory leak during a cyclic cpu-online-offline test.
Signed-off-by: NYu Luming <luming.yu@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

This allows drivers and other code to get the max reported CPU frequency.
Initial use is for scaling ring frequency with GPU frequency in the i915
driver.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>

This patch augments the pstate transition code to error out
(instead of returning 0) when an incorrect pstate is provided.
Suggested-by: NBorislav Petkov <bp@alien8.de>
CC: andre.przywara@amd.com
CC: Mark.Langsdorf@amd.com
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Before this patch if we failed the vid transition would still try to
submit the "new" frequencies to cpufreq.
That is incorrect - also we could submit a non-existing frequency value
which would cause cpufreq to crash. The ultimate fix is in cpufreq
to deal with incorrect values, but this patch improves the error
recovery in the AMD powernowk8 driver.

The failure that was reported was as follows:

powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
...

And transition fails and data->currfid ends up with 0. Since
the machine does not support 800Mhz value when the calculation is
done ('find_khz_freq_from_fid(data->currfid);') it reports the
new frequency as 800000 which is bogus. This patch fixes
the issue during target setting.

The patch however does not fix the issue in 'powernowk8_cpu_init'
where the pol->cur can also be set with the 800000 value:

          pol->cur = find_khz_freq_from_fid(data->currfid);
  dprintk("policy current frequency %d kHz\n", pol->cur);

  /* min/max the cpu is capable of */
  if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {

The fix for that looks to update cpufreq_frequency_table_cpuinfo to
check pol->cur.... but that would cause an regression in how the
acpi-cpufreq driver works (it sets cpu->cur after calling
cpufreq_frequency_table_cpuinfo). Instead the fix will be to let
cpufreq gracefully handle bogus data (another patch).
Acked-by: NBorislav Petkov <bp@alien8.de>
CC: andre.przywara@amd.com
CC: Mark.Langsdorf@amd.com
Reported-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
[v1: Rebased on v3.0-rc2, reduced patch to deal with vid case]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDave Jones <davej@redhat.com>

If the driver submitted an non-existing pol>cur value (say it
used the default initialized value of zero), when the cpufreq
stats tries to setup its initial values it incorrectly sets
stat->last_index to -1 (or 0xfffff...). And cpufreq_stats_update
tries to update at that index location and fails.

This can be caused by:

stat->last_index = freq_table_get_index(stat, policy->cur);

not finding the appropiate frequency in the table (b/c the policy->cur
is wrong) and we end up crashing. The fix however is
concentrated in the 'cpufreq_stats_update' as the last_index
(and old_index) are updated there. Which means it can reset
the last_index to -1 again and on the next iteration cause a crash.

Without this patch, the following crash is observed:

powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
.. snip..
Pid: 1, comm: swapper Not tainted 3.0.0-rc2 #45 MICRO-STAR INTERNATIONAL CO., LTD MS-7094/MS-7094
..snip..
Call Trace:
 [<ffffffff81479248>] cpufreq_stat_notifier_trans+0x48/0x7c
 [<ffffffff81095d68>] notifier_call_chain+0x32/0x5e
 [<ffffffff81095e6b>] __srcu_notifier_call_chain+0x47/0x63
 [<ffffffff81095e96>] srcu_notifier_call_chain+0xf/0x11
 [<ffffffff81477e7a>] cpufreq_notify_transition+0x111/0x134
 [<ffffffff8147b0d4>] powernowk8_target+0x53b/0x617
 [<ffffffff8147723a>] __cpufreq_driver_target+0x2e/0x30
 [<ffffffff8147a127>] cpufreq_governor_dbs+0x339/0x356
 [<ffffffff81477394>] __cpufreq_governor+0xa8/0xe9
 [<ffffffff81477525>] __cpufreq_set_policy+0x132/0x13e
 [<ffffffff8147848d>] cpufreq_add_dev_interface+0x272/0x28c
Reported-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDave Jones <davej@redhat.com>

cpufreq_stats leaves behind its sysfs entries, which causes a panic
when something stumbled across them.
(Discovered by unloading cpufreq_stats while powertop was loaded).
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: stable@kernel.org

Concluding interface update and movement of the driver by making
the DB8500 cpufreq driver compile in the cpufreq subsystem.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This updates the ux500 cpufreq driver to the new interface from the
updated DB8500 PRCMU

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

As part of the ARM arch subsystem migration, move the DB8500
cpufreq driver to drivers/cpufreq as discussed with Dave Jones. The
Makefile is not updated in order to avoid cross-subsystem conflicts
for this file in merges.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NDave Jones <davej@redhat.com>

Since format string handling is part of request_module, there is no
need to construct the module name. As such, drop the redundant sprintf
and heap usage.
Signed-off-by: NKees Cook <kees.cook@canonical.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Fixed brace coding style issue.
Signed-off-by: NKarthigan Srinivasan <karthigan.srinivasan@hp.com>
Signed-off-by: NDave Jones <davej@redhat.com>

When a CPU is taken offline in an SMP system, cpufreq_remove_dev()
nulls out the per-cpu policy before cpufreq_stats_free_table() can
make use of it.  cpufreq_stats_free_table() then skips the
call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related
memory unclaimed each time a CPU-removal occurs. Break up
cpu_stats_free_table into sysfs and table portions, and
call the sysfs portion early.
Signed-off-by: NSteven Finney <steven.finney@palm.com>
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: stable@kernel.org

With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.

How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.

To enabled debugging during runtime, mount debugfs and

$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control

for debugging the complete "cpufreq" module. To achieve the same goal during
boot, append

	ddebug_query="module cpufreq +p"

as a boot parameter to the kernel of your choice.

For more detailled instructions, please see
Documentation/dynamic-debug-howto.txt
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NDave Jones <davej@redhat.com>

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: NJacob Shin <jacob.shin@amd.com>
Acked-by: NMark Langsdorf <mark.langsdorf@amd.com>
Reviewed-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: stable@kernel.org

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

The cpufreq subsystem uses sysdev suspend and resume for
executing cpufreq_suspend() and cpufreq_resume(), respectively,
during system suspend, after interrupts have been switched off on the
boot CPU, and during system resume, while interrupts are still off on
the boot CPU.  In both cases the other CPUs are off-line at the
relevant point (either they have been switched off via CPU hotplug
during suspend, or they haven't been switched on yet during resume).
For this reason, although it may seem that cpufreq_suspend() and
cpufreq_resume() are executed for all CPUs in the system, they are
only called for the boot CPU in fact, which is quite confusing.

To remove the confusion and to prepare for elimiating sysdev
suspend and resume operations from the kernel enirely, convernt
cpufreq to using a struct syscore_ops object for the boot CPU
suspend and resume and rename the callbacks so that their names
reflect their purpose.  In addition, put some explanatory remarks
into their kerneldoc comments.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

None of the existing cpufreq drivers uses the second argument of
its .suspend() callback (which isn't useful anyway), so remove it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NDave Jones <davej@redhat.com>

There cannot be any concurrent access to these through
different cpu sysfs files anymore, because these tunables
are now all global (not per cpu).

I still have some doubts whether some of these locks
were needed at all. Anyway, let's get rid of them.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org

Marked deprecated for quite a whilte now...
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org

Marked deprecated for quite a while now...
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org