Earlier, Ingo Molnar posted a patch to make it so that the kernel would avoid
reading _PPC on his broken T60.  Unfortunately, it seems that with Thomas
Renninger's patch last July to eliminate _PPC evaluations when the processor
driver loads, the kernel never actually reads _PPC at all!  This is problematic
if you happen to boot your non-T60 computer in a state where the BIOS _wants_
_PPC to be something other than zero.

So, put the _PPC evaluation back into acpi_processor_get_performance_info if
ignore_ppc isn't 1.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Conflicts:
	include/acpi/processor.h

Signed-off-by: Len 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: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>

According to the ACPI spec(section 8.4.4.3) OSPM should convey the _PPC
evaluations status to the platform if there exists the _OST object.
The _OST contains two arguments:
	The first is the PERFORMANCE notificatin event.
	The second is the status of _PPC object.
OSPM will convey the _PPC evaluation status to the platform.
Of course when the module parameter of "ignore_ppc" is added, OSPM won't
evaluate the _PPC object. But it will call the _OST object.

At the same time the _OST object will be evaluated only when the PERFORMANCE
notification event is received.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Remove open-coded zalloc_cpumask_var() and zalloc_cpumask_var_node().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.

Add GPL commment to internal.h while we are there.

This does not change any actual console output,
asside from a whitespace fix.

Signed-off-by: Len Brown <len.brown@intel.com>

When BIOS SETUP is changed to disable EIST, some BIOS
hand the OS an un-initialized _PSS:

        Name (_PSS, Package (0x06)
        {
            Package (0x06)
            {
                0x80000000,	// frequency [MHz]
                0x80000000,	// power [mW]
                0x80000000,	// latency [us]
                0x80000000,	// BM latency [us]
                0x80000000,	// control
                0x80000000	// status
            },
	    ...

These are outrageous values for frequency,
power and latency, raising the question where to draw
the line between legal and illegal.  We tend to survive
garbage in the power and latency fields, but we can BUG_ON
when garbage is in the frequency field.

Cpufreq multiplies the frequency by 1000 and stores it in a u32 KHz.
So disregard a _PSS with a frequency so large
that it can't be represented by cpufreq.

https://bugzilla.redhat.com/show_bug.cgi?id=500311

Signed-off-by: Len Brown <len.brown@intel.com>

Conflicts:
	arch/x86/kernel/cpu/cpufreq/longhaul.c

Signed-off-by: Len Brown <len.brown@intel.com>

When cpufreq driver call acpi_processor_preregister_performance() , function
will clean up pr->performance even if there is possibly already registered
other cpufreq driver. The patch fix this potential problem. It also remove
double checks in P domain basic validity code and move these checks to function
where _PSD data is captured.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Impact: cleanup

There are two allocated per-cpu accessor macros with almost identical
spelling.  The original and far more popular is per_cpu_ptr (44
files), so change over the other 4 files.

tj: kill percpu_ptr() and update UP too

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: mingo@redhat.com
Cc: lenb@kernel.org
Cc: cpufreq@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>