From: Christoffer Dall <christoffer.dall@linaro.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: marc.zyngier@arm.com, andre.przywara@arm.com,
will.deacon@arm.com, dave.martin@arm.com,
catalin.marinas@arm.com, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 3/3] arm64/kvm: use alternative auto-nop
Date: Thu, 8 Sep 2016 13:16:48 +0200 [thread overview]
Message-ID: <20160908111648.GZ23592@cbox> (raw)
In-Reply-To: <1473242830-26246-4-git-send-email-mark.rutland@arm.com>
On Wed, Sep 07, 2016 at 11:07:10AM +0100, Mark Rutland wrote:
> Make use of the new alternative_if and alternative_else_nop_endif and
> get rid of our homebew NOP sleds, making the code simpler to read.
homebew?
>
> Note that for __kvm_call_hyp the branch to __vhe_hyp_call has been moved
> out of the alternative sequence, and in the default case there will be
> four additional NOPs executed.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: kvmarm@lists.cs.columbia.edu
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
> arch/arm64/include/asm/kvm_mmu.h | 10 +++-------
> arch/arm64/kvm/hyp.S | 6 +-----
> 2 files changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
> index b6bb834..dff1098 100644
> --- a/arch/arm64/include/asm/kvm_mmu.h
> +++ b/arch/arm64/include/asm/kvm_mmu.h
> @@ -99,14 +99,10 @@
> .macro kern_hyp_va reg
> alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
> and \reg, \reg, #HYP_PAGE_OFFSET_HIGH_MASK
> -alternative_else
> - nop
> -alternative_endif
> -alternative_if_not ARM64_HYP_OFFSET_LOW
> - nop
> -alternative_else
> +alternative_else_nop_endif
> +alternative_if ARM64_HYP_OFFSET_LOW
> and \reg, \reg, #HYP_PAGE_OFFSET_LOW_MASK
> -alternative_endif
> +alternative_else_nop_endif
> .endm
>
> #else
> diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
> index 7ce9315..2726635 100644
> --- a/arch/arm64/kvm/hyp.S
> +++ b/arch/arm64/kvm/hyp.S
> @@ -46,10 +46,6 @@ alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
> hvc #0
> ldr lr, [sp], #16
> ret
> -alternative_else
> +alternative_else_nop_endif
> b __vhe_hyp_call
> - nop
> - nop
> - nop
> -alternative_endif
> ENDPROC(__kvm_call_hyp)
> --
> 1.9.1
>
WARNING: multiple messages have this Message-ID (diff)
From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/3] arm64/kvm: use alternative auto-nop
Date: Thu, 8 Sep 2016 13:16:48 +0200 [thread overview]
Message-ID: <20160908111648.GZ23592@cbox> (raw)
In-Reply-To: <1473242830-26246-4-git-send-email-mark.rutland@arm.com>
On Wed, Sep 07, 2016 at 11:07:10AM +0100, Mark Rutland wrote:
> Make use of the new alternative_if and alternative_else_nop_endif and
> get rid of our homebew NOP sleds, making the code simpler to read.
homebew?
>
> Note that for __kvm_call_hyp the branch to __vhe_hyp_call has been moved
> out of the alternative sequence, and in the default case there will be
> four additional NOPs executed.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: kvmarm at lists.cs.columbia.edu
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
> arch/arm64/include/asm/kvm_mmu.h | 10 +++-------
> arch/arm64/kvm/hyp.S | 6 +-----
> 2 files changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
> index b6bb834..dff1098 100644
> --- a/arch/arm64/include/asm/kvm_mmu.h
> +++ b/arch/arm64/include/asm/kvm_mmu.h
> @@ -99,14 +99,10 @@
> .macro kern_hyp_va reg
> alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
> and \reg, \reg, #HYP_PAGE_OFFSET_HIGH_MASK
> -alternative_else
> - nop
> -alternative_endif
> -alternative_if_not ARM64_HYP_OFFSET_LOW
> - nop
> -alternative_else
> +alternative_else_nop_endif
> +alternative_if ARM64_HYP_OFFSET_LOW
> and \reg, \reg, #HYP_PAGE_OFFSET_LOW_MASK
> -alternative_endif
> +alternative_else_nop_endif
> .endm
>
> #else
> diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
> index 7ce9315..2726635 100644
> --- a/arch/arm64/kvm/hyp.S
> +++ b/arch/arm64/kvm/hyp.S
> @@ -46,10 +46,6 @@ alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
> hvc #0
> ldr lr, [sp], #16
> ret
> -alternative_else
> +alternative_else_nop_endif
> b __vhe_hyp_call
> - nop
> - nop
> - nop
> -alternative_endif
> ENDPROC(__kvm_call_hyp)
> --
> 1.9.1
>
next prev parent reply other threads:[~2016-09-08 11:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-07 10:07 [PATCH 0/3] arm64: alternative: add auto-nop support Mark Rutland
2016-09-07 10:07 ` Mark Rutland
2016-09-07 10:07 ` [PATCH 1/3] arm64: alternative: add auto-nop infrastructure Mark Rutland
2016-09-07 10:07 ` Mark Rutland
2016-09-13 8:36 ` Ard Biesheuvel
2016-09-13 8:36 ` Ard Biesheuvel
2016-09-13 8:57 ` Mark Rutland
2016-09-13 8:57 ` Mark Rutland
2016-09-13 8:59 ` Ard Biesheuvel
2016-09-13 8:59 ` Ard Biesheuvel
2016-09-07 10:07 ` [PATCH 2/3] arm64: use alternative auto-nop Mark Rutland
2016-09-07 10:07 ` Mark Rutland
2016-09-07 10:07 ` [PATCH 3/3] arm64/kvm: " Mark Rutland
2016-09-07 10:07 ` Mark Rutland
2016-09-08 11:16 ` Christoffer Dall [this message]
2016-09-08 11:16 ` Christoffer Dall
2016-09-08 11:33 ` Mark Rutland
2016-09-08 11:33 ` Mark Rutland
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