In order to allow userspace to be mitigated on demand, let's
introduce a new thread flag that prevents the mitigation from
being turned off when exiting to userspace, and doesn't turn
it on on entry into the kernel (with the assumption that the
mitigation is always enabled in the kernel itself).

This will be used by a prctl interface introduced in a later
patch.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

On a system where firmware can dynamically change the state of the
mitigation, the CPU will always come up with the mitigation enabled,
including when coming back from suspend.

If the user has requested "no mitigation" via a command line option,
let's enforce it by calling into the firmware again to disable it.

Similarily, for a resume from hibernate, the mitigation could have
been disabled by the boot kernel. Let's ensure that it is set
back on in that case.
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In order to avoid checking arm64_ssbd_callback_required on each
kernel entry/exit even if no mitigation is required, let's
add yet another alternative that by default jumps over the mitigation,
and that gets nop'ed out if we're doing dynamic mitigation.

Think of it as a poor man's static key...
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

We're about to need the mitigation state in various parts of the
kernel in order to do the right thing for userspace and guests.

Let's expose an accessor that will let other subsystems know
about the state.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

On a system where the firmware implements ARCH_WORKAROUND_2,
it may be useful to either permanently enable or disable the
workaround for cases where the user decides that they'd rather
not get a trap overhead, and keep the mitigation permanently
on or off instead of switching it on exception entry/exit.

In any case, default to the mitigation being enabled.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

As for Spectre variant-2, we rely on SMCCC 1.1 to provide the
discovery mechanism for detecting the SSBD mitigation.

A new capability is also allocated for that purpose, and a
config option.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In a heterogeneous system, we can end up with both affected and
unaffected CPUs. Let's check their status before calling into the
firmware.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In order for the kernel to protect itself, let's call the SSBD mitigation
implemented by the higher exception level (either hypervisor or firmware)
on each transition between userspace and kernel.

We must take the PSCI conduit into account in order to target the
right exception level, hence the introduction of a runtime patching
callback.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

We've so far used the PSCI return codes for SMCCC because they
were extremely similar. But with the new ARM DEN 0070A specification,
"NOT_REQUIRED" (-2) is clashing with PSCI's "PSCI_RET_INVALID_PARAMS".

Let's bite the bullet and add SMCCC specific return codes. Users
can be repainted as and when required.
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In do_page_fault(), we handle some kernel faults early, and simply
die() with a message. For faults handled later, we dump the faulting
address, decode the ESR, walk the page tables, and perform a number of
steps to ensure that this data is reported.

Let's unify the handling of fatal kernel faults with a new
die_kernel_fault() helper, handling all of these details. This is
largely the same as the existing logic in __do_kernel_fault(), except
that addresses are consistently padded to 16 hex characters, as would be
expected for a 64-bit address.

The messages currently logged in do_page_fault are adjusted to fit into
the die_kernel_fault() message template.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The naming of is_permission_fault() makes it sound like it should return
true for permission faults from EL0, but by design, it only does so for
faults from EL1.

Let's make this clear by dropping el1 in the name, as we do for
is_el1_instruction_abort().
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Now that we're seeing CPUs shipping with LSE atomics, default them to
'on' in Kconfig. CPUs without the instructions will continue to use
LDXR/STXR-based sequences, but they will be placed out-of-line by the
compiler.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Writes to ZCR_EL1 are self-synchronising, and so may be expensive
in typical implementations.

This patch adopts the approach used for costly system register
writes elsewhere in the kernel: the system register write is
suppressed if it would not change the stored value.

Since the common case will be that of switching between tasks that
use the same vector length as one another, prediction hit rates on
the conditional branch should be reasonably good, with lower
expected amortised cost than the unconditional execution of a
heavyweight self-synchronising instruction.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Now that we have an accurate view of the physical topology
we need to represent it correctly to the scheduler. Generally MC
should equal the LLC in the system, but there are a number of
special cases that need to be dealt with.

In the case of NUMA in socket, we need to assure that the sched
domain we build for the MC layer isn't larger than the DIE above it.
Similarly for LLC's that might exist in cross socket interconnect or
directory hardware we need to assure that MC is shrunk to the socket
or NUMA node.

This patch builds a sibling mask for the LLC, and then picks the
smallest of LLC, socket siblings, or NUMA node siblings, which
gives us the behavior described above. This is ever so slightly
different than the similar alternative where we look for a cache
layer less than or equal to the socket/NUMA siblings.

The logic to pick the MC layer affects all arm64 machines, but
only changes the behavior for DT/MPIDR systems if the NUMA domain
is smaller than the core siblings (generally set to the cluster).
Potentially this fixes a possible bug in DT systems, but really
it only affects ACPI systems where the core siblings is correctly
set to the socket siblings. Thus all currently available ACPI
systems should have MC equal to LLC, including the NUMA in socket
machines where the LLC is partitioned between the NUMA nodes.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add ACPI_SIG_PPTT to the table so initrd's can override the
system topology.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Geoffrey Blake <geoffrey.blake@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Propagate the topology information from the PPTT tree to the
cpu_topology array. We can get the thread id and core_id by assuming
certain levels of the PPTT tree correspond to those concepts.
The package_id is flagged in the tree and can be found by calling
find_acpi_cpu_topology_package() which terminates
its search when it finds an ACPI node flagged as the physical
package. If the tree doesn't contain enough levels to represent
all of the requested levels then the root node will be returned
for all subsequent levels.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The cluster concept isn't architecturally defined for arm64.
Lets match the name of the arm64 topology field to the kernel macro
that uses it.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The /sys cache entries should support ACPI/PPTT generated cache
topology information.  For arm64, if ACPI is enabled, determine
the max number of cache levels and populate them using the PPTT
table if one is available.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Call ACPI cache parsing routines from base cacheinfo code if ACPI
is enabled. Also stub out cache_setup_acpi and acpi_find_last_cache_level
so that individual architectures can enable ACPI topology parsing.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Now that we have a PPTT parser, in preparation for its use
on arm64, lets build it.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

ACPI 6.2 adds a new table, which describes how processing units
are related to each other in tree like fashion. Caches are
also sprinkled throughout the tree and describe the properties
of the caches in relation to other caches and processing units.

Add the code to parse the cache hierarchy and report the total
number of levels of cache for a given core using
acpi_find_last_cache_level() as well as fill out the individual
cores cache information with cache_setup_acpi() once the
cpu_cacheinfo structure has been populated by the arch specific
code.

An additional patch later in the set adds the ability to report
peers in the topology using find_acpi_cpu_topology()
to report a unique ID for each processing unit at a given level
in the tree. These unique id's can then be used to match related
processing units which exist as threads, within a given
package, etc.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Its helpful to be able to lookup the acpi_processor_id associated
with a logical cpu. Provide an arm64 helper to do this.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Rename and change the type of of_node to indicate
it is a generic pointer which is generally only used
for comparison purposes. In a later patch we will put
an ACPI/PPTT token pointer in fw_token so that
the code which builds the shared cpu masks can be reused.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The original intent in cacheinfo was that an architecture
specific populate_cache_leaves() would probe the hardware
and then cache_shared_cpu_map_setup() and
cache_override_properties() would provide firmware help to
extend/expand upon what was probed. Arm64 was really
the only architecture that was working this way, and
with the removal of most of the hardware probing logic it
became clear that it was possible to simplify the logic a bit.

This patch combines the walk of the DT nodes with the
code updating the cache size/line_size and nr_sets.
cache_override_properties() (which was DT specific) is
then removed. The result is that cacheinfo.of_node is
no longer used as a temporary place to hold DT references
for future calls that update cache properties. That change
helps to clarify its one remaining use (matching
cacheinfo nodes that represent shared caches) which
will be used by the ACPI/PPTT code in the following patches.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In preparation for the next patch, and to aid in
review of that patch, lets move cache_setup_of_node
further down in the module without any changes.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

When waiting for a cacheline to change state in cmpwait, we may immediately
wake-up the first time around the outer loop if the event register was
already set (for example, because of the event stream).

Avoid these spurious wakeups by explicitly clearing the event register
before loading the cacheline and setting the exclusive monitor.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

It is probably safe to assume that all Armv8-A implementations have a
multiplier whose efficiency is comparable or better than a sequence of
three or so register-dependent arithmetic instructions. Select
ARCH_HAS_FAST_MULTIPLIER to get ever-so-slightly nicer codegen in the
few dusty old corners which care.

In a contrived benchmark calling hweight64() in a loop, this does indeed
turn out to be a small win overall, with no measurable impact on
Cortex-A57 but about 5% performance improvement on Cortex-A53.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

"make includecheck" detected few duplicated includes in arch/arm64.

This patch removes the double inclusions.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

VMLINUX_SYMBOL() is no-op unless CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
is defined.  It has ever been selected only by BLACKFIN and METAG.
VMLINUX_SYMBOL() is unneeded for ARM64-specific code.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch increases the ARCH_DMA_MINALIGN to 128 so that it covers the
currently known Cache Writeback Granule (CTR_EL0.CWG) on arm64 and moves
the fallback in cache_line_size() from L1_CACHE_BYTES to this constant.
In addition, it warns (and taints) if the CWG is larger than
ARCH_DMA_MINALIGN as this is not safe with non-coherent DMA.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This reverts commit 97303480.

Commit 97303480 ("arm64: Increase the max granular size") increased
the cache line size to 128 to match Cavium ThunderX, apparently for some
performance benefit which could not be confirmed. This change, however,
has an impact on the network packet allocation in certain circumstances,
requiring slightly over a 4K page with a significant performance
degradation. The patch reverts L1_CACHE_SHIFT back to 6 (64-byte cache
line).

Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pll KVM fixes from Radim Krčmář:
 "ARM:
   - Fix proxying of GICv2 CPU interface accesses
   - Fix crash when switching to BE
   - Track source vcpu git GICv2 SGIs
   - Fix an outdated bit of documentation

  x86:
   - Speed up injection of expired timers (for stable)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: remove APIC Timer periodic/oneshot spikes
  arm64: vgic-v2: Fix proxying of cpuif access
  KVM: arm/arm64: vgic_init: Cleanup reference to process_maintenance
  KVM: arm64: Fix order of vcpu_write_sys_reg() arguments
  KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGI

Pull iommu fixes from Joerg Roedel:

 - fix a compile warning in the AMD IOMMU driver with irq remapping
   disabled

 - fix for VT-d interrupt remapping and invalidation size (caused a
   BUG_ON when trying to invalidate more than 4GB)

 - build fix and a regression fix for broken graphics with old DTS for
   the rockchip iommu driver

 - a revert in the PCI window reservation code which fixes a regression
   with VFIO.

* tag 'iommu-fixes-v4.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: rockchip: fix building without CONFIG_OF
  iommu/vt-d: Use WARN_ON_ONCE instead of BUG_ON in qi_flush_dev_iotlb()
  iommu/vt-d: fix shift-out-of-bounds in bug checking
  iommu/dma: Move PCI window region reservation back into dma specific path.
  iommu/rockchip: Make clock handling optional
  iommu/amd: Hide unused iommu_table_lock
  iommu/vt-d: Fix usage of force parameter in intel_ir_reconfigure_irte()

Pull x86 fix from Thomas Gleixner:
 "Unbreak the CPUID CPUID_8000_0008_EBX reload which got dropped when
  the evaluation of physical and virtual bits which uses the same CPUID
  leaf was moved out of get_cpu_cap()"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Restore CPUID_8000_0008_EBX reload

Pull clocksource fixes from Thomas Gleixner:
 "The recent addition of the early TSC clocksource breaks on machines
  which have an unstable TSC because in case that TSC is disabled, then
  the clocksource selection logic falls back to the early TSC which is
  obviously bogus.

  That also unearthed a few robustness issues in the clocksource
  derating code which are addressed as well"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Rework stale comment
  clocksource: Consistent de-rate when marking unstable
  x86/tsc: Fix mark_tsc_unstable()
  clocksource: Initialize cs->wd_list
  clocksource: Allow clocksource_mark_unstable() on unregistered clocksources
  x86/tsc: Always unregister clocksource_tsc_early

Pull irq fix from Thomas Gleixner:
 "A single fix to prevent false positives in the spurious interrupt
  detector when more than a single demultiplex register is evaluated in
  the Qualcom irq combiner driver"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/qcom: Fix check for spurious interrupts

Pull x86 platform driver fixes from Darren Hart:

 - We missed a case in the Dell config dependencies resulting in a
   possible bad configuration, resolve it by giving up on trying to keep
   DELL_LAPTOP visible in the menu and make it depend on DELL_SMBIOS.

 - Fix a null pointer dereference at module unload for the asus-wireless
   driver.

* tag 'platform-drivers-x86-v4.17-2' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: Kconfig: Fix dell-laptop dependency chain.
  platform/x86: asus-wireless: Fix NULL pointer dereference

Pull USB fixes from Greg KH:
 "Here are some USB driver fixes for 4.17-rc4.

  The majority of them are some USB gadget fixes that missed my last
  pull request. The "largest" patch in here is a fix for the old visor
  driver that syzbot found 6 months or so ago and I finally remembered
  to fix it.

  All of these have been in linux-next with no reported issues"

* tag 'usb-4.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  Revert "usb: host: ehci: Use dma_pool_zalloc()"
  usb: typec: tps6598x: handle block reads separately with plain-I2C adapters
  usb: typec: tcpm: Release the role mux when exiting
  USB: Accept bulk endpoints with 1024-byte maxpacket
  xhci: Fix use-after-free in xhci_free_virt_device
  USB: serial: visor: handle potential invalid device configuration
  USB: serial: option: adding support for ublox R410M
  usb: musb: trace: fix NULL pointer dereference in musb_g_tx()
  usb: musb: host: fix potential NULL pointer dereference
  usb: gadget: composite Allow for larger configuration descriptors
  usb: dwc3: gadget: Fix list_del corruption in dwc3_ep_dequeue
  usb: dwc3: gadget: dwc3_gadget_del_and_unmap_request() can be static
  usb: dwc2: pci: Fix error return code in dwc2_pci_probe()
  usb: dwc2: WA for Full speed ISOC IN in DDMA mode.
  usb: dwc2: dwc2_vbus_supply_init: fix error check
  usb: gadget: f_phonet: fix pn_net_xmit()'s return type

Since the commit "8003c9ae: add APIC Timer periodic/oneshot mode VMX
preemption timer support", a Windows 10 guest has some erratic timer
spikes.

Here the results on a 150000 times 1ms timer without any load:
	  Before 8003c9ae | After 8003c9ae
Max           1834us          |  86000us
Mean          1100us          |   1021us
Deviation       59us          |    149us
Here the results on a 150000 times 1ms timer with a cpu-z stress test:
	  Before 8003c9ae | After 8003c9ae
Max          32000us          | 140000us
Mean          1006us          |   1997us
Deviation      140us          |  11095us

The root cause of the problem is starting hrtimer with an expiry time
already in the past can take more than 20 milliseconds to trigger the
timer function.  It can be solved by forward such past timers
immediately, rather than submitting them to hrtimer_start().
In case the timer is periodic, update the target expiration and call
hrtimer_start with it.

v2: Check if the tsc deadline is already expired. Thank you Mika.
v3: Execute the past timers immediately rather than submitting them to
hrtimer_start().
v4: Rearm the periodic timer with advance_periodic_target_expiration() a
simpler version of set_target_expiration(). Thank you Paolo.

Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
8003c9ae ("KVM: LAPIC: add APIC Timer periodic/oneshot mode VMX preemption timer support")
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>