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    Subject[PATCH v5 0/2] x86/fpu: Make AMX state ready for CPU idle
    Date
    Here is the fifth version of this series.

    I've addressed Dave's comment [2] assuming that the change makes sense to
    folks:
    * Check the AMX_TILE feature bit instead of XGETBV1.
    * Massage the changelog accordingly.

    While many people had their eyeballs on this, Rafael's ACK was given so
    far. Hopefully this can attracts more acknowledgment or endorsement if it
    looks fine.

    === Cover Letter ===

    AMX state is a large state (at least 8KB or more). Entering CPU idle with
    this non-initialized large state may result in shallow states while a
    deeper low-power state is available.

    We can confirm this behavior is implementation-specific. Section 3.3 in [3]
    will be updated to clarify this.

    This patch set ensures the AMX state is initialized before entering the CPU
    idle state.

    The patch set is based on 5.19-rc1. It is also available here:
    git://github.com/intel/amx-linux.git tilerelease

    [1]: V4 https://lore.kernel.org/lkml/20220517222430.24524-1-chang.seok.bae@intel.com/
    [2]: https://lore.kernel.org/lkml/25a2a82f-b5e5-0fce-86c8-03d7da5fcdd1@intel.com/
    [3]: Intel Architecture Instruction Set Extension Programming Reference
    May 2021, https://software.intel.com/content/dam/develop/external/us/en/documents-tps/architecture-instruction-set-extensions-programming-reference.pdf

    Chang S. Bae (2):
    x86/fpu: Add a helper to prepare AMX state for low-power CPU idle
    intel_idle: Add a new flag to initialize the AMX state

    arch/x86/include/asm/fpu/api.h | 2 ++
    arch/x86/include/asm/special_insns.h | 9 +++++++++
    arch/x86/kernel/fpu/core.c | 14 ++++++++++++++
    drivers/idle/intel_idle.c | 18 ++++++++++++++++--
    4 files changed, 41 insertions(+), 2 deletions(-)


    base-commit: f2906aa863381afb0015a9eb7fefad885d4e5a56
    --
    2.17.1

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