The existing interface only has a pre-order callback. This change
adds an additional parameter for a post-order callback which will
be more useful for bus scans. ACPICA BZ 779.

Also update the external calls to acpi_walk_namespace.

http://www.acpica.org/bugzilla/show_bug.cgi?id=779Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.

Why is this needed:

Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
  - any userspace prog writing to scaling_max_freq
  - thermal limitations
  - hardware (_PPC in ACPI case) limitiations

Therefore export bios_limit (in kHz) to:
  - Point the user that it's the BIOS (broken or intended) which limits
    frequency
  - Export it as a sysfs interface for userspace progs.
    While this was a rarely used feature on laptops, there will appear
    more and more server implemenations providing "Green IT" features like
    allowing the service processor to limit the frequency. People want
    to know about HW/BIOS frequency limitations.

All ACPI P-state driven cpufreq drivers are covered with this patch:
  - powernow-k8
  - powernow-k7
  - acpi-cpufreq

Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations

# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation

CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>

The "unsigned int processor" everywhere confused Rusty, leading to
breakage when he passed in smp_processor_id().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

Set the transition latency to value smaller than CPUFREQ_ETERNAL so
governors other than "performance" work (like the "ondemand" one).

The value is found in "AMD PowerNow! Technology Platform Design Guide for
Embedded Processors" dated December 2000 (AMD doc #24267A). There is the
answer to one of FAQs on page 40 which states that suggested complete transition
period is 200 us.

Tested on K6-2+ CPU with K6-3 core (model 13, stepping 4).
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NDave Jones <davej@redhat.com>

It's still mugging the current process's cpumask, but as comment in
1ff6e97f says, it's not a trivial fix.

So, at least we can use a cpumask_var_t to do the Wrong Thing the Right Way :)
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
To: cpufreq@vger.kernel.org
Cc: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

"[CPUFREQ] cpumask: avoid playing with cpus_allowed in speedstep-ich.c"
changed the code to mistakenly pass the current cpu as the "processor"
argument of speedstep_get_frequency(), whereas it should be the type of
the processor.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14340

Based on a patch by Dave Mueller.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDominik Brodowski <linux@brodo.de>
Reported-by: NDave Mueller <dave.mueller@gmx.ch>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

Removing the SMT/HT check, since the Errata doesn't mention
Hyper-Threading.

Adding in a printk, so that the user knows why acpi-cpufreq refuses to
load.  Also, once system is blacklisted, don't repeat checks to see if
blacklisted.  This also causes the message to only be printed once,
rather than for each CPU.
Signed-off-by: NJohn L. Villalovos <john.l.villalovos@intel.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Not makes it a bool before the comparison.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NDave Jones <davej@redhat.com>

There is a typo in the longhaul detection code so only Longhaul v1 or Longhaul v3
is selected. The Longhaul v2 is not selected even for CPUs which are capable of.

Tested on PCChips Giga Pro board. Frequency changes work and the Longhaul v2
detects that the board is not capable of changing CPU voltage.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NDave Jones <davej@redhat.com>

This patch converts the existing power tracer into an event tracer,
so that power events (C states and frequency changes) can be
tracked via "perf".

This also removes the perl script that was used to demo the tracer;
its functionality is being replaced entirely with timechart.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130542.6d314860@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fixes bugzilla #13780

From: Kurt Roeckx <kurt@roeckx.be>
Signed-off-by: NDave Jones <davej@redhat.com>

Move some of the aperf/mperf code out from the cpufreq driver
thingy so that other people can enjoy it too.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move the APERFMPERF capacility into a X86_FEATURE flag so that it
can be used outside of the acpi cpufreq driver.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Create a blacklist for processors that should not load the acpi-cpufreq module.

The initial entry in the blacklist function is the Intel 0f68 processor.  It's
specification update mentions errata AL30 which implies that cpufreq should not
run on this processor.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Remove an obsolete check that used to prevent there being more
than 2 low P-states.  Now that low-to-low P-states changes are
enabled, it prevents otherwise workable configurations with
multiple low P-states.
Signed-off-by: NMark Langsdorf <mark.langsdorf@amd.com>
Tested-by: NKrists Krilovs <pow@pow.za.net>
Signed-off-by: NDave Jones <davej@redhat.com>

Commit 5fd29d6c ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide support for family 0xf processors with 2 P-states
below the elevator voltage.  Remove the checks that prevent
this configuration from being supported and increase the
transition voltage to prevent errors during the transition.
Signed-off-by: NMark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Remove all old-style cpumask operators, and cpumask_t.

Also: get rid of the unused define_siblings function.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NMark Langsdorf <mark.langsdorf@amd.com>
Tested-by: NMark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

cpumask: avoid playing with cpus_allowed in powernow-k8.c

It's generally a very bad idea to mug some process's cpumask: it could
legitimately and reasonably be changed by root, which could break us
(if done before our code) or them (if we restore the wrong value).

I did not replace powernowk8_target; it needs fixing, but it grabs a
mutex (so no smp_call_function_single here) but Mark points out it can
be called multiple times per second, so work_on_cpu is too heavy.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
To: cpufreq@vger.kernel.org
Acked-by: NMark Langsdorf <mark.langsdorf@amd.com>
Tested-by: NMark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Impact: don't play with current's cpumask

It's generally a very bad idea to mug some process's cpumask: it could
legitimately and reasonably be changed by root, which could break us
(if done before our code) or them (if we restore the wrong value).

Use rdmsr_on_cpu and wrmsr_on_cpu instead.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
To: cpufreq@vger.kernel.org
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NDave Jones <davej@redhat.com>

Impact: don't play with current's cpumask

It's generally a very bad idea to mug some process's cpumask: it could
legitimately and reasonably be changed by root, which could break us
(if done before our code) or them (if we restore the wrong value).

We use smp_call_function_single: this had the advantage of being more
efficient, too.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
To: cpufreq@vger.kernel.org
Cc: Dominik Brodowski <linux@brodo.de>
Signed-off-by: NDave Jones <davej@redhat.com>

Make powernowk8_get() similar to powernowk8_target() and powernowk8_verify()
in the way it obtains "powernow_data" for a given CPU.

Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
Reviewed-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Tested-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: NLangsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>

By definition, "cpuinfo_cur_freq" should report the value from HW. So, don't
depend on the cached value. Instead read P-state directly from HW, while
taking into account the erratum 311 workaround for Fam 11h processors.

Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
Reviewed-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Tested-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: NLangsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>

This symbol doesn't need file-global scope.

Cc: "Zhang, Rui" <rui.zhang@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Cc: Leo Milano <lmilano@gmx.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

Mess cleanup in powernow_k8_acpi_pst_values() function.
Signed-off-by: NLuis Henriques <henrix@sapo.pt>
Signed-off-by: NDave Jones <davej@redhat.com>

This doesn't fix anything, but it's expected that a transition latency of 0
could cause trouble in the future.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

The e_powersaver driver for VIA's C7 CPU's needs to be marked as
DANGEROUS as it configures the CPU to power states that are out
of specification.

According to Centaur, all systems with C7 and Nano CPU's support
the ACPI p-state method.  Thus, the acpi-cpufreq driver should
be used instead.
Signed-off-by: NHarald Welte <HaraldWelte@viatech.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The VIA/Centaur C7, C7-M and Nano CPU's all support ACPI based cpu p-states
using a MSR interface.  The Linux driver just never made use of it, since in
addition to the check for the EST flag it also checked if the vendor is Intel.
Signed-off-by: NHarald Welte <HaraldWelte@viatech.com>
[ Removed the vendor checks entirely  - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These are defined as static cpumask_var_t so if MAXSMP is not used,
they are cleared already.  Avoid surprises when MAXSMP is enabled.
Signed-off-by: NYinghai Lu <yinghai.lu@kernel.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The powernow-k8 driver checks to see that the Performance Control/Status
Registers are declared as FFH (functional fixed hardware) by the BIOS.
However, this check got broken in the commit:
 0e64a0c9
 [CPUFREQ] checkpatch cleanups for powernow-k8

Fix based on an original patch from Naga Chumbalkar.
Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Slightly modified by trenn@suse.de -> only do this on fam 10h and fam 11h.

Currently powernow-k8 determines CPU frequency from ACPI PSS objects, but
according to AMD family 11h BKDG this frequency is just a rounded value:

  "CoreFreq (MHz) = The CPU COF specified by MSRC001_00[6B:64][CpuFid]
  rounded to the nearest 100 Mhz."

As a consequnce powernow-k8 reports wrong CPU frequency on some systems,
e.g. on Turion X2 Ultra:

  powernow-k8: Found 1 AMD Turion(tm)X2 Ultra DualCore Mobile ZM-82
               processors (2 cpu cores) (version 2.20.00)
  powernow-k8:    0 : pstate 0 (2200 MHz)
  powernow-k8:    1 : pstate 1 (1100 MHz)
  powernow-k8:    2 : pstate 2 (600 MHz)

But this is wrong as frequency for Pstate2 is 550 MHz. x86info reports it
correctly:

  #x86info -a |grep Pstate
  ...
  Pstate-0: fid=e, did=0, vid=24 (2200MHz)
  Pstate-1: fid=e, did=1, vid=30 (1100MHz)
  Pstate-2: fid=e, did=2, vid=3c (550MHz) (current)

Solution is to determine the frequency directly from Pstate MSRs instead
of using rounded values from ACPI table.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>

- Make the message shorter and easier to grep for
- Use printk_once instead of WARN_ONCE (functionality of these was mixed)
Signed-off-by: NThomas Renninger <trenn@suse.de>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

arch/x86/kernel/cpu/cpufreq/powernow-k7.c:172: warning: 'invalidate_entry' defined but not used
Reported-by: NToralf Förster <toralf.foerster@gmx.de>
Signed-off-by: NDave Jones <davej@redhat.com>

Some atom procs don't do freq scaling (such as the atom 330 on my own
littlefalls2 board). By adding the atom family here, we at least get
the benefit of passive cooling in a thermal emergency. Not sure how
to see that its actually helping any, but the driver does bind and
claim its functioning on my atom 330.
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Take already available policy->cpuinfo.max_freq and get rid of acpi-cpufreq
specific max_freq variable.

This implies that P0 is always the highest frequency which should always
be true as ACPI spec says:
As a result, the zeroth entry describes the highest performance state
Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix for a regression that was introduced by earlier commit
18b2646f on Mon Apr 6 11:26:08 2009

Regression resulted in the below error happened on systems with
software coordination where per_cpu acpi data will not be initiated for
secondary CPUs in a P-state domain.

On Tue, 2009-04-14 at 23:01 -0700, Zhang, Yanmin wrote:
 My machine hanged with kernel 2.6.30-rc2 when script read
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor.
>
> opps happens in get_measured_perf:
>
>         cur.aperf.whole = readin.aperf.whole -
>                                 per_cpu(drv_data, cpu)->saved_aperf;
>
> Because per_cpu(drv_data, cpu)=NULL.
>
> So function get_measured_perf should check if (per_cpu(drv_data,
> cpu)==NULL)
> and return 0 if it's NULL.

--------------sys log------------------

BUG: unable to handle kernel NULL pointer dereference at
0000000000000020
IP: [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
PGD a7dd88067 PUD a7ccf5067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
CPU 0
Modules linked in: video output
Pid: 2091, comm: kondemand/0 Not tainted 2.6.30-rc2 #1 MP Server
RIP: 0010:[<ffffffff8021af75>]  [<ffffffff8021af75>]
get_measured_perf+0x4a/0xf9
RSP: 0018:ffff880a7d56de20  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000046241a42b6 RCX: ffff88004d219000
RDX: 000000000000b660 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff880a7f052000 R08: 00000046241a42b6 R09: ffffffff807639f0
R10: 00000000ffffffea R11: ffffffff802207f4 R12: ffff880a7f052000
R13: ffff88004d20e460 R14: 0000000000ddd5a6 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88004d200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000020 CR3: 0000000a7f1bf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kondemand/0 (pid: 2091, threadinfo ffff880a7d56c000, task
ffff880a7d4d18c0)
Stack:
 ffff880a7f052078 ffffffff803efd54 00000046241a42b6 000000462ffa9e95
 0000000000000001 0000000000000001 00000000ffffffea ffffffff8064f41a
 0000000000000012 0000000000000012 ffff880a7f052000 ffffffff80650547
Call Trace:
 [<ffffffff803efd54>] ? kobject_get+0x12/0x17
 [<ffffffff8064f41a>] ? __cpufreq_driver_getavg+0x42/0x57
 [<ffffffff80650547>] ? do_dbs_timer+0x147/0x272
 [<ffffffff80650400>] ? do_dbs_timer+0x0/0x272
 [<ffffffff802474ca>] ? worker_thread+0x15b/0x1f5
 [<ffffffff8024a02c>] ? autoremove_wake_function+0x0/0x2e
 [<ffffffff8024736f>] ? worker_thread+0x0/0x1f5
 [<ffffffff80249f0d>] ? kthread+0x54/0x83
 [<ffffffff8020c87a>] ? child_rip+0xa/0x20
 [<ffffffff80249eb9>] ? kthread+0x0/0x83
 [<ffffffff8020c870>] ? child_rip+0x0/0x20
Code: 99 a6 03 00 31 c9 85 c0 0f 85 c3 00 00 00 89 df 4c 8b 44 24 10 48
c7 c2 60 b6 00 00 48 8b 0c fd e0 30 a5 80 4c 89 c3 48 8b 04 0a <48> 2b
58 20 48 8b 44 24 18 48 89 1c 24 48 8b 34 0a 48 2b 46 28
RIP  [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
 RSP <ffff880a7d56de20>
CR2: 0000000000000020
---[ end trace 2b8fac9a49e19ad4 ]---
Tested-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

It turns out that 'smp_call_function_many()' doesn't work at all like
'smp_call_function_single()', and my change to Andrew's patch to use it
rather than a loop over all CPU's acpi-cpufreq doesn't work.

My bad.

'smp_call_function_many()' has two "features" (aka "documented bugs"):

 (a) it needs to be called with preemption disabled, because it uses
     smp_processor_id() without guarding the CPU lookup with 'get_cpu()'
     and 'put_cpu()' like the 'single' variant does.

 (b) even if the current CPU is part of the CPU mask, it won't do the
     call on that CPU.

Still, we're better off trying to use 'smp_call_function_many()' than
looping over CPU's, since it at least in theory allows us to use a
broadcast IPI and do it all in parallel.  So let's just work around the
silly semantic bugs in that function.
Reported-and-tested-by: NAli Gholami Rudi <ali@rudi.ir>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>