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    SubjectRe: [PATCH] arm64: entry: Save some nops when CONFIG_ARM64_PSEUDO_NMI is not set
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    在 2022/1/19 17:35, Mark Rutland 写道:
    > On Wed, Jan 19, 2022 at 02:40:58PM +0800, He Ying wrote:
    >> Hi all,
    >>
    >> Ping. Any comments?
    > The patch looks fine, but as it's the middle of the merge window people
    > are busy and unlikely to look at this for the next few days.
    >
    > Generally it's a good idea to wait until rc1 or rc2, rebase atop that,
    > and post the updated patch. Stuff like this usually gets queued around
    > rc3/rc4 time.
    OK. Thanks for your comment.
    >
    >> 锟斤拷 2022/1/12 11:24, He Ying 写锟斤拷:
    >>> Arm64 pseudo-NMI feature code brings some additional nops
    >>> when CONFIG_ARM64_PSEUDO_NMI is not set, which is not
    >>> necessary. So add necessary ifdeffery to avoid it.
    >>>
    >>> Signed-off-by: He Ying <heying24@huawei.com>
    > FWIW:
    >
    > Acked-by: Mark Rutland <mark.rutland@arm.com>
    >
    > Mark.
    >
    >>> ---
    >>> arch/arm64/kernel/entry.S | 4 ++++
    >>> 1 file changed, 4 insertions(+)
    >>>
    >>> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
    >>> index 2f69ae43941d..ffc32d3d909a 100644
    >>> --- a/arch/arm64/kernel/entry.S
    >>> +++ b/arch/arm64/kernel/entry.S
    >>> @@ -300,6 +300,7 @@ alternative_else_nop_endif
    >>> str w21, [sp, #S_SYSCALLNO]
    >>> .endif
    >>> +#ifdef CONFIG_ARM64_PSEUDO_NMI
    >>> /* Save pmr */
    >>> alternative_if ARM64_HAS_IRQ_PRIO_MASKING
    >>> mrs_s x20, SYS_ICC_PMR_EL1
    >>> @@ -307,6 +308,7 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING
    >>> mov x20, #GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET
    >>> msr_s SYS_ICC_PMR_EL1, x20
    >>> alternative_else_nop_endif
    >>> +#endif
    >>> /* Re-enable tag checking (TCO set on exception entry) */
    >>> #ifdef CONFIG_ARM64_MTE
    >>> @@ -330,6 +332,7 @@ alternative_else_nop_endif
    >>> disable_daif
    >>> .endif
    >>> +#ifdef CONFIG_ARM64_PSEUDO_NMI
    >>> /* Restore pmr */
    >>> alternative_if ARM64_HAS_IRQ_PRIO_MASKING
    >>> ldr x20, [sp, #S_PMR_SAVE]
    >>> @@ -339,6 +342,7 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING
    >>> dsb sy // Ensure priority change is seen by redistributor
    >>> .L__skip_pmr_sync\@:
    >>> alternative_else_nop_endif
    >>> +#endif
    >>> ldp x21, x22, [sp, #S_PC] // load ELR, SPSR
    > .

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