The cpb sysfs attribute is only exposed by the ACPI cpufreq driver
after a runtime check.  For this purpose, the driver keeps a NULL
placeholder in its table of sysfs attributes and replaces the NULL
with a pointer to an attribute structure if it decides to expose
cpb.

That is confusing, so make the driver set the pointer to the cpb
attribute structure upfront and replace it with NULL if the
attribute should not be exposed instead.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

After commit 8cfcfd39 (acpi-cpufreq: Fix an ACPI perf unregister
issue) we store both a pointer to per-CPU data of the first policy
CPU and the number of that CPU which are redundant.

Since the CPU number has to be stored anyway for the unregistration,
the pointer to the CPU's per-CPU data may be dropped and we can
access the data in question via per_cpu_ptr().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

acpi_processor_unregister_performance() actually doesn't use its
first argument, so drop it and update the callers accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Return codes aren't honored properly in cpufreq_set_policy(). This can
lead to two problems:
- wrong errors propagated to sysfs
- we try to do next state-change even if the previous one failed

cpufreq_governor_dbs() now returns proper errors on all invalid
state-transition requests and this code should honor that.
Reviewed-and-tested-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With previous commit, governors have started to return errors on invalid
state-transition requests. We already have a WARN for an invalid
state-transition request in cpufreq_governor_dbs(). This does trigger
today, as the sequence of events isn't guaranteed by cpufreq core.

Lets stop warning on that for now, and make sure we don't enter an
invalid state.
Reviewed-and-tested-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There can be races where the request has come to a wrong state. For
example INIT followed by STOP (instead of START) or START followed by
EXIT (instead of STOP).

Address these races by making sure the state-machine never gets into
any invalid state. Also return an error if an invalid state-transition
is requested.
Reviewed-and-tested-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some part of cs_dbs_timer() and od_dbs_timer() is exactly same and is
unnecessarily duplicated.

Create the real work-handler in cpufreq_governor.c and put the common
code in this routine (dbs_timer()).

Shouldn't make any functional change.
Reviewed-and-tested-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some information is common to all CPUs belonging to a policy, but are
kept on per-cpu basis. Lets keep that in another structure common to all
policy->cpus. That will make updates/reads to that less complex and less
error prone.

The memory for cpu_common_dbs_info is allocated/freed at INIT/EXIT, so
that it we don't reallocate it for STOP/START sequence. It will be also
be used (in next patch) while the governor is stopped and so must not be
freed that early.
Reviewed-and-tested-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Just call it 'policy', cur_policy is unnecessarily long and doesn't
have any special meaning.
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is called as 'cdbs' at most of the places and 'cpu_dbs' at others.
Lets use 'cdbs' consistently for better readability.
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Its not common info to all CPUs, but a structure representing common
type of cpu info to both governor types. Lets drop 'common_' from its
name.
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Its not used at all, drop it.
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Delayed work was named as 'work' and to access work within it we do
work.work. Not much readable. Rename delayed_work as 'dwork'.
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

HWP previously was only enabled at driver load time, on the boot
CPU, however, HWP must be enabled per package. Move the code to
enable HWP to the cpufreq driver init path so that it will be
called per CPU.
Signed-off-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Tested-by: NDavid Zhuang <david.zhuang@oracle.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fixed coding style issues found by checkpatch.pl tool. Changed
space indentation to tab, removed unneccesary braces, removed
space between MODULE macros and parentheses.

REMARKS: failed to 'make' this file with error message
'fatal error: asm/mach-types.h: No such file or directory'.
Signed-off-by: NCristian Ardelean <cristian97.ardelean@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As policy->cpu may not be same in acpi_cpufreq_cpu_init() and
acpi_cpufreq_cpu_exit(). There is a risk that we use different CPU
to un/register ACPI performance. So acpi_processor_unregister_performance()
may not be able to do the cleanup work. That causes a memory leak. And
if there will be another acpi_processor_register_performance() call,
it may also fail thanks to the internal check of pr->performace.

So add a new struct acpi_cpufreq_data field, acpi_perf_cpu, to fix
this issue.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_init_policy() can fail, and we don't do anything except a call
to ->exit() on that. The policy should be freed if this happens.

Do it properly.
Reported-and-tested-by: N"Jon Medhurst (Tixy)" <tixy@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

These labels are are named in two ways normally:
 - Based on what caused to jump to such labels
 - Based on what we do under such labels

We follow the first naming convention today and that leads to multiple
labels for doing the same work. Fix it by switching to the second way of
naming them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Drivers can store their internal per-policy information in
policy->driver_data, lets use it.

we have benefits after this replacing.
1) memory saving.
2) policy is shared by several cpus, per_cpu seems not correct. using
*driver_data* is more reasonable.
3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might
change during cpu hotplug. So sometimes we cant't free *data*, use
*driver_data* to fix it.
4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of
policy->cpu is set to *data*, if we try to get cpufreq on other cpus, we
get zero instead of correct values. Use *driver_data* to fix it.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Users of freq table may want to access it for any CPU from
policy->related_cpus mask. One such user is cpu-cooling layer. It gets a
list of 'clip_cpus' (equivalent to policy->related_cpus) during
registration and tries to get freq_table for the first CPU of this mask.

If the CPU, for which it tries to fetch freq_table, is offline,
cpufreq_frequency_get_table() fails. This happens because it relies on
cpufreq_cpu_get_raw() for its functioning which returns policy only for
online CPUs.

The fix is to access the policy data structure for the given CPU
directly (which also returns a valid policy for offline CPUs), but the
policy itself has to be active (meaning that at least one CPU using it
is online) for the frequency table to be returned.

Because we will be using 'cpufreq_cpu_data' now, which is internal to
the cpufreq core, move cpufreq_frequency_get_table() to cpufreq.c.
Reported-and-tested-by: NPi-Cheng Chen <pi-cheng.chen@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When all CPUs of a policy are hot-unplugged, we EXIT the governor but
don't mark policy->governor as NULL. This was done in order to keep last
used governor's information intact in sysfs, while the CPUs are offline.

But we also need to clear policy->governor when restoring the policy.

Because policy->governor still points to the last governor while policy
is restored, following sequence of event happens:
 - cpufreq_init_policy() called while restoring policy
 - find_governor() matches last_governor string for present governors and
   returns last used governor's pointer, say ondemand. policy->governor
   already has the same address, unless the governor was removed in
   between.
 - cpufreq_set_policy() is called with both old/new policies governor set
   as ondemand.
 - Because governors matched, we skip governor initialization and return
   after calling __cpufreq_governor(CPUFREQ_GOV_LIMITS). Because the
   governor wasn't initialized for this policy, it returned -EBUSY.
 - cpufreq_init_policy() exits the policy on this error, but doesn't
   destroy it properly (should be fixed separately).
 - And so we enter a scenario where the policy isn't completely
   initialized but used.

Fix this by setting policy->governor to NULL while restoring the policy.
Reported-and-tested-by: NPi-Cheng Chen <pi-cheng.chen@linaro.org>
Reported-and-tested-by: N"Jon Medhurst (Tixy)" <tixy@linaro.org>
Reported-and-tested-by: NSteven Rostedt <rostedt@goodmis.org>
Fixes: 18bf3a12 (cpufreq: Mark policy->governor = NULL for inactive policies)
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When split BAR is enabled, the driver needs to dump out the split BAR
registers rather than the original 64bit BAR registers.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

The unsafe doorbell and scratchpad access should display reason when
WARN is called.  Otherwise we get a stack dump without any explanation.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Printouts driver name and version to indicate what is being loaded.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Benchmarking showed a significant performance increase with the MTU size
to 64k instead of 16k.  Change the driver default to 64k.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Instead of using the platform code names, use the correct platform names
to identify the respective Intel NTB hardware.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Disable DMA usage by default, since the CPU provides much better
performance with write combining.  Provide a module parameter to enable
DMA usage when offloading the memcpy is preferred.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Changing the memory window BAR mappings to write combining significantly
boosts the performance.  We will also use memcpy that uses non-temporal
store, which showed performance improvement when doing non-cached
memcpys.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Allocate memory for the NUMA node of the NTB device.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Allocate memory and request the DMA channel for the same NUMA node as
the NTB device.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

When the ntb transport is connecting and waiting for the peer, the debug
console receives lots of debug level messages about the remote qp link
status being down.  Rate limit those messages.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

This is a simple debugging driver that enables the doorbell and
scratch pad registers to be read and written from the debugfs.  This
tool enables more complicated debugging to be scripted from user space.
This driver may be used to test that your ntb hardware and drivers are
functioning at a basic level.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

This is a simple ping pong driver that exercises the scratch pads and
doorbells of the ntb hardware.  This driver may be used to test that
your ntb hardware and drivers are functioning at a basic level.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Add module parameters for the addresses to be used in B2B topology.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Reset the link stats when the link goes down.  In particular, the TX and
RX index and count must be reset, or else the TX side will be sending
packets to the RX side where the RX side is not expecting them.  Reset
all the stats, to be consistent.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

On link down, don't advance RX index to the next entry.  The next entry
should never be valid after receiving the link down flag.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

The same message "qp %d: Link Down\n" was printed at two locations in
ntb_transport.  Change the messages so they are distinct.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Set errata flags for the specific device IDs to which they apply,
instead of the whole Xeon hardware class.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Link training should be enabled in the driver probe for root port mode.
We should not have to wait for transport to be loaded for this to
happen.  Otherwise the ntb device will not show up on the transparent
bridge side of the link.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

The transport was writing and then reading the peer scratch pad,
essentially reading what it just wrote instead of exchanging any
information with the peer.  The transport expects the peer values to be
the same as the local values, so this issue was not obvious.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>