Do not write zeroes to APERF and MPERF by ondemand governor. With this
change, other users can share these MSRs for reads.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Change structure name to make the code cleaner and simpler. No
functionality change in this patch.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some BIOSes report very high frequency transition latency which are plainly
wrong on CPus that can change frequency using native MSR interface.

One such system is IBM T42 (2327-8ZU) as reported by Owen Taylor and
Rik van Riel.

cpufreq_ondemand driver uses this transition latency to come up with a
reasonable sampling interval to sample CPU usage and with such high
latency value, ondemand sampling interval ends up being very high
(0.5 sec, in this particular case), resulting in performance impact due to
slow response to increasing frequency.

Fix it by capping-off the transition latency to 20uS for native MSR based
frequency transitions.

mjg: We've confirmed that this also helps on the X31
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NDave Jones <davej@redhat.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: NRusty Russell <rusty@rustcorp.com.au>
Cc: mingo@redhat.com
Cc: lenb@kernel.org
Cc: cpufreq@vger.kernel.org
Signed-off-by: NTejun Heo <tj@kernel.org>

Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.
Signed-off-by: NJason Baron <jbaron@redhat.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>

Impact: cleanup

Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

-tip testing found this crash:

> [   35.258515] calling  acpi_cpufreq_init+0x0/0x127 @ 1
> [   35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [   35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [   35.267554] PGD 0
> [   35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC

arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...

Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: use new work_on_cpu function to reduce stack usage

Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().

Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.

Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Tested-by: NDieter Ries <clip2@gmx.de>
Tested-by: NMaciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: use new work_on_cpu function to reduce stack usage

Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().

Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.

Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Tested-by: NDieter Ries <clip2@gmx.de>
Tested-by: NMaciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>

-tip testing found this crash:

> [   35.258515] calling  acpi_cpufreq_init+0x0/0x127 @ 1
> [   35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [   35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [   35.267554] PGD 0
> [   35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC

arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...

Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix potential boot crash on MAXSMP

Remove code left over by:

  50c668d6: Revert "cpumask: use work_on_cpu in acpi-cpufreq.c for drv_read

That cmd.cpumask is not allocated anymore. No impact on default !MAXSMP
kernels.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit 7503bfba.

Dieter Ries reported bootup soft-hangs and bisected it back to
this commit, and reverting this commit gave him a working system.

The commit introduces work_on_cpu() use into the cpufreq code,
but that is subtly problematic from a lock hierarchy POV: the
hotplug-cpu lock is an highlevel lock that is taken before
lowlevel locks, and in this codepath we are called with the
policy lock taken.

Dieter did not have lockdep enabled so we dont have a nice stack
trace proof for this, but using work_on_cpu() in such a lowlevel
place certainly looks wrong, so we revert the patch.

work_on_cpu() needs to be reworked to be more generally usable.
Reported-by: NDieter Ries <clip2@gmx.de>
Tested-by: NDieter Ries <clip2@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: use new cpumask API to reduce stack usage

Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for read_measured_perf_ctrs().

Basically splits off the work function from get_measured_perf which is
run on the designated cpu.  Moves definition of struct perf_cur out of
function local namespace, and is used as the work function argument.
References in get_measured_perf use values in the perf_cur struct.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: use new cpumask API to reduce stack usage

Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().

Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, reduce stack usage, use new cpumask API.

Replace the cpumask_t in struct drv_cmd with a cpumask_var_t.  Remove unneeded
online_policy_cpus cpumask_t in acpi_cpufreq_target.  Update refs to use
new cpumask API.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: use new cpumask API to reduce memory usage

This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS.  cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NDave Jones <davej@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Reduce inter-node memory traffic.

Reduces inter-node memory traffic (offloading the global system bus)
by allocating referenced struct cpumasks on the same node as the
referring struct.
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Reduce memory usage, use new API.

This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS.  cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).

(Changes to powernow-k* by <travis>.)
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: new "power-tracer" ftrace plugin

This patch adds a C/P-state ftrace plugin that will generate
detailed statistics about the C/P-states that are being used,
so that we can look at detailed decisions that the C/P-state
code is making, rather than the too high level "average"
that we have today.

An example way of using this is:

 mount -t debugfs none /sys/kernel/debug
 echo cstate > /sys/kernel/debug/tracing/current_tracer
 echo 1 > /sys/kernel/debug/tracing/tracing_enabled
 sleep 1
 echo 0 > /sys/kernel/debug/tracing/tracing_enabled
 cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add a cpu parameter to __cpufreq_driver_getavg(). This is needed for software
cpufreq coordination where policy->cpu may not be same as the CPU on which we
want to getavg frequency.

A follow-on patch will use this parameter to getavg freq from all cpus
in policy->cpus.

Change since last patch. Fix the offline/online and suspend/resume
oops reported by Youquan Song <youquan.song@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NDave Jones <davej@redhat.com>

add error handling for cpufreq_register_driver() error
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: cpufreq@lists.linux.org.uk
Signed-off-by: NDave Jones <davej@redhat.com>

  * Replace previous instances of the cpumask_of_cpu_ptr* macros
    with a the new (lvalue capable) generic cpumask_of_cpu().
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

  * This patch replaces the dangerous lvalue version of cpumask_of_cpu
    with new cpumask_of_cpu_ptr macros.  These are patterned after the
    node_to_cpumask_ptr macros.

    In general terms, if there is a cpumask_of_cpu_map[] then a pointer to
    the cpumask_of_cpu_map[cpu] entry is used.  The cpumask_of_cpu_map
    is provided when there is a large NR_CPUS count, reducing
    greatly the amount of code generated and stack space used for
    cpumask_of_cpu().  The pointer to the cpumask_t value is needed for
    calling set_cpus_allowed_ptr() to reduce the amount of stack space
    needed to pass the cpumask_t value.

    If there isn't a cpumask_of_cpu_map[], then a temporary variable is
    declared and filled in with value from cpumask_of_cpu(cpu) as well as
    a pointer variable pointing to this temporary variable.  Afterwards,
    the pointer is used to reference the cpumask value.  The compiler
    will optimize out the extra dereference through the pointer as well
    as the stack space used for the pointer, resulting in identical code.

    A good example of the orthogonal usages is in net/sunrpc/svc.c:

	case SVC_POOL_PERCPU:
	{
		unsigned int cpu = m->pool_to[pidx];
		cpumask_of_cpu_ptr(cpumask, cpu);

		*oldmask = current->cpus_allowed;
		set_cpus_allowed_ptr(current, cpumask);
		return 1;
	}
	case SVC_POOL_PERNODE:
	{
		unsigned int node = m->pool_to[pidx];
		node_to_cpumask_ptr(nodecpumask, node);

		*oldmask = current->cpus_allowed;
		set_cpus_allowed_ptr(current, nodecpumask);
		return 1;
	}
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change references from for_each_cpu_mask to for_each_cpu_mask_nr
where appropriate
Reviewed-by: NPaul Jackson <pj@sgi.com>
Reviewed-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

commit 2d474871e2fb092eb46a0930aba5442e10eb96cc
Author: Mike Travis <travis@sgi.com>
Date:   Mon May 12 21:21:13 2008 +0200

Currently, affected_cpus shows which CPUs need to have their frequency
coordinated in software.  When hardware coordination is in use, the contents
of this file appear the same as when no coordination is required.  This can
lead to some confusion among user-space programs, for example, that do not
know that extra coordination is required to force a CPU core to a particular
speed to control power consumption.

To fix this, create a "related_cpus" attribute that always displays the
coordination map regardless of whatever coordination strategy the cpufreq
driver uses (sw or hw).  If the cpufreq driver does not provide a value, fall
back to policy->cpus.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

We checked the hardware freq with OS cached freq value in get_cur_freqon_cpu().
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NDave Jones <davej@redhat.com>

  * Use new set_cpus_allowed_ptr() function added by previous patch,
    which instead of passing the "newly allowed cpus" cpumask_t arg
    by value,  pass it by pointer:

    -int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
    +int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)

  * Cleanup uses of CPU_MASK_ALL.

  * Collapse other NR_CPUS changes to arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
    Use pointers to cpumask_t arguments whenever possible.

Depends on:
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Cc: Len Brown <len.brown@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change the following static arrays sized by NR_CPUS to
per_cpu data variables:

	acpi_cpufreq_data *drv_data[NR_CPUS]
Signed-off-by: NMike Travis <travis@sgi.com>
Reviewed-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

cpu_data is currently an array defined using NR_CPUS.  This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code.  An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index.  This corresponds to the index into a cpumask_t as well as the
per_cpu index.  It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NChristoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This is from an earlier message from 'Christoph Lameter':

    cpu_core_map is currently an array defined using NR_CPUS. This means that
    we overallocate since we will rarely really use maximum configured cpu.

    If we put the cpu_core_map into the per cpu area then it will be allocated
    for each processor as it comes online.

    This means that the core map cannot be accessed until the per cpu area
    has been allocated. Xen does a weird thing here looping over all processors
    and zeroing the masks that are not yet allocated and that will be zeroed
    when they are allocated. I commented the code out.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Three main sets of changes:

1) dmi_get_system_info() return value should have been marked const,
   since callers should not be changing that data.

2) const-ify DMI internals, since DMI firmware tables should,
   whenever possible, be marked const to ensure we never ever write to
   that data area.

3) const-ify DMI API, to enable marking tables const where possible
   in low-level drivers.

And if we're really lucky, this might enable some additional
optimizations on the part of the compiler.

The bulk of the changes are #2 and #3, which are interrelated.  #1 could
have been a separate patch, but it was so small compared to the others,
it was easier to roll it into this changeset.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

This patch addresses some issues in x86/x86-64 acpi-cpufreq driver:

1.  Current memory allocation for acpi_perf_data is actually open-coded
   alloc_percpu().  The patch defines and handles acpi_perf_data as percpu
   data.  The code will be cleaner and easier to be maintained with this
   change.

2. Won't load driver in acpi_cpufreq_early_init() failure case.

3. Add __init for acpi_cpufreq_early_init().
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The local variable "covered" is used without initialization in i386
acpi-cpufreq driver.  The initial value of covered should be 0.  The bug
will cause memory leak when hit.  The following patch fixes this bug.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make sure that the _PSS list is sorted in
descending order by typical power dissipation.

http://bugzilla.kernel.org/show_bug.cgi?id=7880Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

During recent acpi-cpufreq changes, writing to PERF_CTL msr
changed from RMW of entire 64 bit to RMW of low 32 bit and clearing of
upper 32 bit. Fix it back to do a proper RMW of the MSR.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NDave Jones <davej@redhat.com>

[CPUFREQ] Uninitialized use of cmd.val in arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c:acpi_cpufreq_target()

cmd.val was used uninitialized on the line below.
Signed-off-by: NGuillaume Chazarain <guichaz@yahoo.fr>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NDave Jones <davej@redhat.com>