From: Mark Rutland <mark.rutland@arm.com>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
Sami Tolvanen <samitolvanen@google.com>
Subject: Re: [PATCH] arm64: scs: Drop unused 'tmp' argument to scs_{load,save} asm macros
Date: Thu, 27 May 2021 12:03:12 +0100 [thread overview]
Message-ID: <20210527110312.GB34323@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20210527105529.21967-1-will@kernel.org>
On Thu, May 27, 2021 at 11:55:29AM +0100, Will Deacon wrote:
> The scs_load and scs_save asm macros don't make use of the mandatory
> 'tmp' register argument, so drop it and fix up the callers.
>
> Cc: Sami Tolvanen <samitolvanen@google.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>
I see this has been the case since commit:
51189c7a7ed1b4ed ("arm64: scs: Store absolute SCS stack pointer value in thread_info")
... so this looks good to me:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
>
> Applies against for-next/boot
>
> arch/arm64/include/asm/scs.h | 8 ++++----
> arch/arm64/kernel/entry.S | 8 ++++----
> arch/arm64/kernel/head.S | 2 +-
> 3 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/include/asm/scs.h b/arch/arm64/include/asm/scs.h
> index eaa2cd92e4c1..8297bccf0784 100644
> --- a/arch/arm64/include/asm/scs.h
> +++ b/arch/arm64/include/asm/scs.h
> @@ -9,18 +9,18 @@
> #ifdef CONFIG_SHADOW_CALL_STACK
> scs_sp .req x18
>
> - .macro scs_load tsk, tmp
> + .macro scs_load tsk
> ldr scs_sp, [\tsk, #TSK_TI_SCS_SP]
> .endm
>
> - .macro scs_save tsk, tmp
> + .macro scs_save tsk
> str scs_sp, [\tsk, #TSK_TI_SCS_SP]
> .endm
> #else
> - .macro scs_load tsk, tmp
> + .macro scs_load tsk
> .endm
>
> - .macro scs_save tsk, tmp
> + .macro scs_save tsk
> .endm
> #endif /* CONFIG_SHADOW_CALL_STACK */
>
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 294f24e16fee..3153f1448cdb 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -275,7 +275,7 @@ alternative_else_nop_endif
>
> mte_set_kernel_gcr x22, x23
>
> - scs_load tsk, x20
> + scs_load tsk
> .else
> add x21, sp, #PT_REGS_SIZE
> get_current_task tsk
> @@ -375,7 +375,7 @@ alternative_if ARM64_WORKAROUND_845719
> alternative_else_nop_endif
> #endif
> 3:
> - scs_save tsk, x0
> + scs_save tsk
>
> #ifdef CONFIG_ARM64_PTR_AUTH
> alternative_if ARM64_HAS_ADDRESS_AUTH
> @@ -979,8 +979,8 @@ SYM_FUNC_START(cpu_switch_to)
> mov sp, x9
> msr sp_el0, x1
> ptrauth_keys_install_kernel x1, x8, x9, x10
> - scs_save x0, x8
> - scs_load x1, x8
> + scs_save x0
> + scs_load x1
> ret
> SYM_FUNC_END(cpu_switch_to)
> NOKPROBE(cpu_switch_to)
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index 070ed53c049d..6a700526b117 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -412,7 +412,7 @@ SYM_FUNC_END(__create_page_tables)
> stp xzr, xzr, [sp, #S_STACKFRAME]
> add x29, sp, #S_STACKFRAME
>
> - scs_load \tsk, \tmp1
> + scs_load \tsk
>
> adr_l \tmp1, __per_cpu_offset
> ldr w\tmp2, [\tsk, #TSK_CPU]
> --
> 2.31.1.818.g46aad6cb9e-goog
>
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next prev parent reply other threads:[~2021-05-27 11:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 10:55 [PATCH] arm64: scs: Drop unused 'tmp' argument to scs_{load, save} asm macros Will Deacon
2021-05-27 11:03 ` Mark Rutland [this message]
2021-05-27 15:08 ` Sami Tolvanen
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