[PATCH] arm64: scs: Drop unused 'tmp' argument to scs_{load, save} asm macros

[Sami Tolvanen]

Hi Will,

On Thu, May 27, 2021 at 3:55 AM Will Deacon <will at kernel.org> 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 at google.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Signed-off-by: Will Deacon <will at kernel.org>
> ---
>
> 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]

Looks good to me, thanks for cleaning this up!

Reviewed-by: Sami Tolvanen <samitolvanen at google.com>

Sami