From:   Usama Arif <usama.arif@bytedance.com>
To:     dwmw2@infradead.org, tglx@linutronix.de, kim.phillips@amd.com,
        brgerst@gmail.com
Cc:     piotrgorski@cachyos.org, oleksandr@natalenko.name,
        arjan@linux.intel.com, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, hpa@zytor.com, x86@kernel.org,
        pbonzini@redhat.com, paulmck@kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        rcu@vger.kernel.org, mimoja@mimoja.de, hewenliang4@huawei.com,
        thomas.lendacky@amd.com, seanjc@google.com, pmenzel@molgen.mpg.de,
        fam.zheng@bytedance.com, punit.agrawal@bytedance.com,
        simon.evans@bytedance.com, liangma@liangbit.com,
        Usama Arif <usama.arif@bytedance.com>
Subject: [PATCH v13 00/11] Parallel CPU bringup for x86_64
Date:   Thu,  2 Mar 2023 11:12:16 +0000
Message-Id: <20230302111227.2102545-1-usama.arif@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The main code change over v12 is to fix the build error when
CONFIG_FORCE_NR_CPUS is present.

The commit message for removing initial stack has also been improved, typos
have been fixed and extra comments have been added to make code clearer.

Thanks,
Usama

Changes across versions:
v2: Cut it back to just INIT/SIPI/SIPI in parallel for now, nothing more
v3: Clean up x2apic patch, add MTRR optimisation, lock topology update
    in preparation for more parallelisation.
v4: Fixes to the real mode parallelisation patch spotted by SeanC, to
    avoid scribbling on initial_gs in common_cpu_up(), and to allow all
    24 bits of the physical X2APIC ID to be used. That patch still needs
    a Signed-off-by from its original author, who once claimed not to
    remember writing it at all. But now we've fixed it, hopefully he'll
    admit it now :)
v5: rebase to v6.1 and remeasure performance, disable parallel bringup
    for AMD CPUs.
v6: rebase to v6.2-rc6, disabled parallel boot on amd as a cpu bug and
    reused timer calibration for secondary CPUs.
v7: [David Woodhouse] iterate over all possible CPUs to find any existing
    cluster mask in alloc_clustermask. (patch 1/9)
    Keep parallel AMD support enabled in AMD, using APIC ID in CPUID leaf
    0x0B (for x2APIC mode) or CPUID leaf 0x01 where 8 bits are sufficient.
    Included sanity checks for APIC id from 0x0B. (patch 6/9)
    Removed patch for reusing timer calibration for secondary CPUs.
    commit message and code improvements.
v8: Fix CPU0 hotplug by setting up the initial_gs, initial_stack and
    early_gdt_descr.
    Drop trampoline lock and bail if APIC ID not found in find_cpunr.
    Code comments improved and debug prints added.
v9: Drop patch to avoid repeated saves of MTRR at boot time.
    rebased and retested at v6.2-rc8.
    added kernel doc for no_parallel_bringup and made do_parallel_bringup
    __ro_after_init.
v10: Fixed suspend/resume not working with parallel smpboot.
     rebased and retested to 6.2.
     fixed checkpatch errors.
v11: Added patches from Brian Gerst to remove the global variables initial_gs,
     initial_stack, and early_gdt_descr from the 64-bit boot code
     (https://lore.kernel.org/all/20230222221301.245890-1-brgerst@gmail.com/).
v12: Fixed compilation errors, acquire tr_lock for every stack setup in
     trampoline_64.S.
     Rearranged commits for a cleaner git history.
v13: Fix build error with CONFIG_FORCE_NR_CPUS.
     Commit message improved, typos fixed and extra comments added.

Brian Gerst (3):
  x86/smpboot: Remove initial_stack on 64-bit
  x86/smpboot: Remove early_gdt_descr on 64-bit
  x86/smpboot: Remove initial_gs

David Woodhouse (8):
  x86/apic/x2apic: Allow CPU cluster_mask to be populated in parallel
  cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h>
  cpu/hotplug: Add dynamic parallel bringup states before
    CPUHP_BRINGUP_CPU
  x86/smpboot: Reference count on smpboot_setup_warm_reset_vector()
  x86/smpboot: Split up native_cpu_up into separate phases and document
    them
  x86/smpboot: Support parallel startup of secondary CPUs
  x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel
  x86/smpboot: Serialize topology updates for secondary bringup

 .../admin-guide/kernel-parameters.txt         |   3 +
 arch/x86/include/asm/processor.h              |   6 +-
 arch/x86/include/asm/realmode.h               |   4 +-
 arch/x86/include/asm/smp.h                    |  15 +-
 arch/x86/include/asm/topology.h               |   2 -
 arch/x86/kernel/acpi/sleep.c                  |  30 +-
 arch/x86/kernel/apic/apic.c                   |   2 +-
 arch/x86/kernel/apic/x2apic_cluster.c         | 126 ++++---
 arch/x86/kernel/asm-offsets.c                 |   1 +
 arch/x86/kernel/cpu/common.c                  |   6 +-
 arch/x86/kernel/head_64.S                     | 132 +++++--
 arch/x86/kernel/smpboot.c                     | 350 +++++++++++++-----
 arch/x86/realmode/init.c                      |   3 +
 arch/x86/realmode/rm/trampoline_64.S          |  27 +-
 arch/x86/xen/smp_pv.c                         |   4 +-
 arch/x86/xen/xen-head.S                       |   2 +-
 include/linux/cpuhotplug.h                    |   2 +
 include/linux/smpboot.h                       |   7 +
 kernel/cpu.c                                  |  31 +-
 kernel/smpboot.h                              |   2 -
 20 files changed, 556 insertions(+), 199 deletions(-)

-- 
2.25.1