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

Pull arm64 updates from Will Deacon:
 "CPU features:

   - Remove ARM64_HAS_NO_HW_PREFETCH copy_page() optimisation for ye
     olde Thunder-X machines

   - Avoid mapping KPTI trampoline when it is not required

   - Make CPU capability API more robust during early initialisation

  Early idreg overrides:

   - Remove dependencies on core kernel helpers from the early
     command-line parsing logic in preparation for moving this code
     before the kernel is mapped

  FPsimd:

   - Restore kernel-mode fpsimd context lazily, allowing us to run
     fpsimd code sequences in the kernel with pre-emption enabled

  KBuild:

   - Install 'vmlinuz.efi' when CONFIG_EFI_ZBOOT=y

   - Makefile cleanups

  LPA2 prep:

   - Preparatory work for enabling the 'LPA2' extension, which will
     introduce 52-bit virtual and physical addressing even with 4KiB
     pages (including for KVM guests).

  Misc:

   - Remove dead code and fix a typo

  MM:

   - Pass NUMA node information for IRQ stack allocations

  Perf:

   - Add perf support for the Synopsys DesignWare PCIe PMU

   - Add support for event counting thresholds (FEAT_PMUv3_TH)
     introduced in Armv8.8

   - Add support for i.MX8DXL SoCs to the IMX DDR PMU driver.

   - Minor PMU driver fixes and optimisations

  RIP VPIPT:

   - Remove what support we had for the obsolete VPIPT I-cache policy

  Selftests:

   - Improvements to the SVE and SME selftests

  Stacktrace:

   - Refactor kernel unwind logic so that it can used by BPF unwinding
     and, eventually, reliable backtracing

  Sysregs:

   - Update a bunch of register definitions based on the latest XML drop
     from Arm"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (87 commits)
  kselftest/arm64: Don't probe the current VL for unsupported vector types
  efi/libstub: zboot: do not use $(shell ...) in cmd_copy_and_pad
  arm64: properly install vmlinuz.efi
  arm64/sysreg: Add missing system instruction definitions for FGT
  arm64/sysreg: Add missing system register definitions for FGT
  arm64/sysreg: Add missing ExtTrcBuff field definition to ID_AA64DFR0_EL1
  arm64/sysreg: Add missing Pauth_LR field definitions to ID_AA64ISAR1_EL1
  arm64: memory: remove duplicated include
  arm: perf: Fix ARCH=arm build with GCC
  arm64: Align boot cpucap handling with system cpucap handling
  arm64: Cleanup system cpucap handling
  MAINTAINERS: add maintainers for DesignWare PCIe PMU driver
  drivers/perf: add DesignWare PCIe PMU driver
  PCI: Move pci_clear_and_set_dword() helper to PCI header
  PCI: Add Alibaba Vendor ID to linux/pci_ids.h
  docs: perf: Add description for Synopsys DesignWare PCIe PMU driver
  arm64: irq: set the correct node for shadow call stack
  Revert "perf/arm_dmc620: Remove duplicate format attribute #defines"
  arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD
  arm64: fpsimd: Preserve/restore kernel mode NEON at context switch
  ...

2 files changed, 73 insertions, 1 deletions

diff --git a/Documentation/arch/arm64/arm-acpi.rst b/Documentation/arch/arm64/arm-acpi.rst
index a46c34fa9604..e59e4505d0d9 100644
--- a/Documentation/arch/arm64/arm-acpi.rst
+++ b/Documentation/arch/arm64/arm-acpi.rst
@@ -130,7 +130,7 @@ When an Arm system boots, it can either have DT information, ACPI tables,
 or in some very unusual cases, both.  If no command line parameters are used,
 the kernel will try to use DT for device enumeration; if there is no DT
 present, the kernel will try to use ACPI tables, but only if they are present.
-In neither is available, the kernel will not boot.  If acpi=force is used
+If neither is available, the kernel will not boot.  If acpi=force is used
 on the command line, the kernel will attempt to use ACPI tables first, but
 fall back to DT if there are no ACPI tables present.  The basic idea is that
 the kernel will not fail to boot unless it absolutely has no other choice.
diff --git a/Documentation/arch/arm64/perf.rst b/Documentation/arch/arm64/perf.rst
index 1f87b57c2332..997fd716b82f 100644
--- a/Documentation/arch/arm64/perf.rst
+++ b/Documentation/arch/arm64/perf.rst
@@ -164,3 +164,75 @@ and should be used to mask the upper bits as needed.
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/arch/arm64/tests/user-events.c
 .. _tools/lib/perf/tests/test-evsel.c:
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/lib/perf/tests/test-evsel.c
+
+Event Counting Threshold
+==========================================
+
+Overview
+--------
+
+FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on
+events whose count meets a specified threshold condition. For example if
+threshold_compare is set to 2 ('Greater than or equal'), and the
+threshold is set to 2, then the PMU counter will now only increment by
+when an event would have previously incremented the PMU counter by 2 or
+more on a single processor cycle.
+
+To increment by 1 after passing the threshold condition instead of the
+number of events on that cycle, add the 'threshold_count' option to the
+commandline.
+
+How-to
+------
+
+These are the parameters for controlling the feature:
+
+.. list-table::
+   :header-rows: 1
+
+   * - Parameter
+     - Description
+   * - threshold
+     - Value to threshold the event by. A value of 0 means that
+       thresholding is disabled and the other parameters have no effect.
+   * - threshold_compare
+     - | Comparison function to use, with the following values supported:
+       |
+       | 0: Not-equal
+       | 1: Equals
+       | 2: Greater-than-or-equal
+       | 3: Less-than
+   * - threshold_count
+     - If this is set, count by 1 after passing the threshold condition
+       instead of the value of the event on this cycle.
+
+The threshold, threshold_compare and threshold_count values can be
+provided per event, for example:
+
+.. code-block:: sh
+
+  perf stat -e stall_slot/threshold=2,threshold_compare=2/ \
+            -e dtlb_walk/threshold=10,threshold_compare=3,threshold_count/
+
+In this example the stall_slot event will count by 2 or more on every
+cycle where 2 or more stalls happen. And dtlb_walk will count by 1 on
+every cycle where the number of dtlb walks were less than 10.
+
+The maximum supported threshold value can be read from the caps of each
+PMU, for example:
+
+.. code-block:: sh
+
+  cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max
+
+  0x000000ff
+
+If a value higher than this is given, then opening the event will result
+in an error. The highest possible maximum is 4095, as the config field
+for threshold is limited to 12 bits, and the Perf tool will refuse to
+parse higher values.
+
+If the PMU doesn't support FEAT_PMUv3_TH, then threshold_max will read
+0, and attempting to set a threshold value will also result in an error.
+threshold_max will also read as 0 on aarch32 guests, even if the host
+is running on hardware with the feature.