Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
"A quick summary: perf support for Branch Record Buffer Extensions

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
"A quick summary: perf support for Branch Record Buffer Extensions
(BRBE), typical PMU hardware updates, small additions to MTE for
store-only tag checking and exposing non-address bits to signal
handlers, HAVE_LIVEPATCH enabled on arm64, VMAP_STACK forced on.

There is also a TLBI optimisation on hardware that does not require
break-before-make when changing the user PTEs between contiguous and
non-contiguous.

More details:

Perf and PMU updates:

- Add support for new (v3) Hisilicon SLLC and DDRC PMUs

- Add support for Arm-NI PMU integrations that share interrupts
between clock domains within a given instance

- Allow SPE to be configured with a lower sample period than the
minimum recommendation advertised by PMSIDR_EL1.Interval

- Add suppport for Arm's "Branch Record Buffer Extension" (BRBE)

- Adjust the perf watchdog period according to cpu frequency changes

- Minor driver fixes and cleanups

Hardware features:

- Support for MTE store-only checking (FEAT_MTE_STORE_ONLY)

- Support for reporting the non-address bits during a synchronous MTE
tag check fault (FEAT_MTE_TAGGED_FAR)

- Optimise the TLBI when folding/unfolding contiguous PTEs on
hardware with FEAT_BBM (break-before-make) level 2 and no TLB
conflict aborts

Software features:

- Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable()
and using the text-poke API for late module relocations

- Force VMAP_STACK always on and change arm64_efi_rt_init() to use
arch_alloc_vmap_stack() in order to avoid KASAN false positives

ACPI:

- Improve SPCR handling and messaging on systems lacking an SPCR
table

Debug:

- Simplify the debug exception entry path

- Drop redundant DBG_MDSCR_* macros

Kselftests:

- Cleanups and improvements for SME, SVE and FPSIMD tests

Miscellaneous:

- Optimise loop to reduce redundant operations in contpte_ptep_get()

- Remove ISB when resetting POR_EL0 during signal handling

- Mark the kernel as tainted on SEA and SError panic

- Remove redundant gcs_free() call"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
arm64/gcs: task_gcs_el0_enable() should use passed task
arm64: Kconfig: Keep selects somewhat alphabetically ordered
arm64: signal: Remove ISB when resetting POR_EL0
kselftest/arm64: Handle attempts to disable SM on SME only systems
kselftest/arm64: Fix SVE write data generation for SME only systems
kselftest/arm64: Test SME on SME only systems in fp-ptrace
kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
kselftest/arm64: Allow sve-ptrace to run on SME only systems
arm64/mm: Drop redundant addr increment in set_huge_pte_at()
kselftest/arm4: Provide local defines for AT_HWCAP3
arm64: Mark kernel as tainted on SAE and SError panic
arm64/gcs: Don't call gcs_free() when releasing task_struct
drivers/perf: hisi: Support PMUs with no interrupt
drivers/perf: hisi: Relax the event number check of v2 PMUs
drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
drivers/perf: hisi: Simplify the probe process for each DDRC version
perf/arm-ni: Support sharing IRQs within an NI instance
perf/arm-ni: Consolidate CPU affinity handling
...

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perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)

The ARMv9.2 architecture introduces the optional Branch Record Buffer
Extension (BRBE), which records information about bra

perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)

The ARMv9.2 architecture introduces the optional Branch Record Buffer
Extension (BRBE), which records information about branches as they are
executed into set of branch record registers. BRBE is similar to x86's
Last Branch Record (LBR) and PowerPC's Branch History Rolling Buffer
(BHRB).

BRBE supports filtering by exception level and can filter just the
source or target address if excluded to avoid leaking privileged
addresses. The h/w filter would be sufficient except when there are
multiple events with disjoint filtering requirements. In this case, BRBE
is configured with a union of all the events' desired branches, and then
the recorded branches are filtered based on each event's filter. For
example, with one event capturing kernel events and another event
capturing user events, BRBE will be configured to capture both kernel
and user branches. When handling event overflow, the branch records have
to be filtered by software to only include kernel or user branch
addresses for that event. In contrast, x86 simply configures LBR using
the last installed event which seems broken.

It is possible on x86 to configure branch filter such that no branches
are ever recorded (e.g. -j save_type). For BRBE, events with a
configuration that will result in no samples are rejected.

Recording branches in KVM guests is not supported like x86. However,
perf on x86 allows requesting branch recording in guests. The guest
events are recorded, but the resulting branches are all from the host.
For BRBE, events with branch recording and "exclude_host" set are
rejected. Requiring "exclude_guest" to be set did not work. The default
for the perf tool does set "exclude_guest" if no exception level
options are specified. However, specifying kernel or user events
defaults to including both host and guest. In this case, only host
branches are recorded.

BRBE can support some additional exception branch types compared to
x86. On x86, all exceptions other than syscalls are recorded as IRQ.
With BRBE, it is possible to better categorize these exceptions. One
limitation relative to x86 is we cannot distinguish a syscall return
from other exception returns. So all exception returns are recorded as
ERET type. The FIQ branch type is omitted as the only FIQ user is Apple
platforms which don't support BRBE. The debug branch types are omitted
as there is no clear need for them.

BRBE records are invalidated whenever events are reconfigured, a new
task is scheduled in, or after recording is paused (and the records
have been recorded for the event). The architecture allows branch
records to be invalidated by the PE under implementation defined
conditions. It is expected that these conditions are rare.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Co-developed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
tested-by: Adam Young <admiyo@os.amperecomputing.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250611-arm-brbe-v19-v23-4-e7775563036e@kernel.org
[will: Fix sparse warnings about mixed declarations and code.
Fix C99 comment syntax.]
Signed-off-by: Will Deacon <will@kernel.org>

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