In certain system configurations it may not be desirable to use some
C-states assumed to be available by intel_idle and the driver needs
to be prevented from using them even before the cpuidle sysfs
interface becomes accessible to user space.  Currently, the only way
to achieve that is by setting the 'max_cstate' module parameter to a
value lower than the index of the shallowest of the C-states in
question, but that may be overly intrusive, because it effectively
makes all of the idle states deeper than the 'max_cstate' one go
away (and the C-state to avoid may be in the middle of the range
normally regarded as available).

To allow that limitation to be overcome, introduce a new module
parameter called 'states_off' to represent a list of idle states to
be disabled by default in the form of a bitmask and update the
documentation to cover it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For diagnostics, it is generally useful to be able to make intel_idle
take the system's ACPI tables into consideration even if that is not
required for the processor model in there, so introduce a new module
parameter, 'use_acpi', to make that happen and update the documentation
to cover it.

While at it, fix the 'no_acpi' module parameter name in the
documentation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull x86 cpu-features updates from Ingo Molnar:
 "The biggest change in this cycle was a large series from Sean
  Christopherson to clean up the handling of VMX features. This both
  fixes bugs/inconsistencies and makes the code more coherent and
  future-proof.

  There are also two cleanups and a minor TSX syslog messages
  enhancement"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/cpu: Remove redundant cpu_detect_cache_sizes() call
  x86/cpu: Print "VMX disabled" error message iff KVM is enabled
  KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs
  perf/x86: Provide stubs of KVM helpers for non-Intel CPUs
  KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits
  KVM: VMX: Check for full VMX support when verifying CPU compatibility
  KVM: VMX: Use VMX feature flag to query BIOS enabling
  KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR
  x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured
  x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl()
  x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*
  x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs
  x86/vmx: Introduce VMX_FEATURES_*
  x86/cpu: Clear VMX feature flag if VMX is not fully enabled
  x86/zhaoxin: Use common IA32_FEAT_CTL MSR initialization
  x86/centaur: Use common IA32_FEAT_CTL MSR initialization
  x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked
  x86/intel: Initialize IA32_FEAT_CTL MSR at boot
  tools/x86: Sync msr-index.h from kernel sources
  selftests, kvm: Replace manual MSR defs with common msr-index.h
  ...

Move the irtl_ns_units[] definition into irtl_2_usec() which is the
only user of it, use div_u64() for the division in there (as the
divisor is small enough) and use the NSEC_PER_USEC symbol for the
divisor.  Also convert the irtl_2_usec() comment to a proper
kerneldo one.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Move intel_idle_verify_cstate(), auto_demotion_disable() and
c1e_promotion_disable() closer to their callers.

While at it, annotate intel_idle_verify_cstate() with __init,
as it is only used during the initialization of the driver.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Annotate the functions that are only used at the initialization time
with __init and the data structures used by them with __initdata or
__initconst.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Move intel_idle_cpuidle_devices_uninit() closer to its caller,
intel_idle_init(), add the __init modifier to its header, drop a
redundant local variable from it and fix up its kerneldoc comment.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Notice that intel_idle_state_table_update() only needs to be called
if icpu is not NULL, so fold it into intel_idle_init_cstates_icpu(),
and pass a pointer to the driver object to
intel_idle_cpuidle_driver_init() as an argument instead of
referencing it locally in there.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of comparing intel_idle_cpuidle_devices with NULL apply
the "!" (not) operator to it when checking it against NULL.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no particular reason why intel_idle_probe() needs to be
a separate function and folding it into intel_idle_init() causes
the code to be somewhat easier to follow, so do just that.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>