On Fri, 31 Oct 2025 11:39:15 +0100
Ard Biesheuvel <ardb+git@google.com> wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
>
> Switch to the more abstract 'scoped_ksimd()' API, which will be modified
> in a future patch to transparently allocate a kernel mode FP/SIMD state
> buffer on the stack, so that kernel mode FP/SIMD code remains
> preemptible in principe, but without the memory overhead that adds 528
> bytes to the size of struct task_struct.
>
> Reviewed-by: Eric Biggers <ebiggers@kernel.org>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Hi Ard,
Trivial comment inline.
> ---
> arch/arm64/crypto/sm3-ce-glue.c | 15 ++++++++-------
> arch/arm64/crypto/sm3-neon-glue.c | 16 ++++++----------
> 2 files changed, 14 insertions(+), 17 deletions(-)
>
> diff --git a/arch/arm64/crypto/sm3-ce-glue.c b/arch/arm64/crypto/sm3-ce-glue.c
> index eac6f5fa0abe..24c1fcfae072 100644
> --- a/arch/arm64/crypto/sm3-ce-glue.c
> +++ b/arch/arm64/crypto/sm3-ce-glue.c
> @@ -5,7 +5,6 @@
> * Copyright (C) 2018 Linaro Ltd <ard.biesheuvel@linaro.org>
> */
>
> -#include <asm/neon.h>
> #include <crypto/internal/hash.h>
> #include <crypto/sm3.h>
> #include <crypto/sm3_base.h>
> @@ -13,6 +12,8 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
>
> +#include <asm/simd.h>
> +
> MODULE_DESCRIPTION("SM3 secure hash using ARMv8 Crypto Extensions");
> MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
> MODULE_LICENSE("GPL v2");
> @@ -25,18 +26,18 @@ static int sm3_ce_update(struct shash_desc *desc, const u8 *data,
> {
> int remain;
>
> - kernel_neon_begin();
> - remain = sm3_base_do_update_blocks(desc, data, len, sm3_ce_transform);
> - kernel_neon_end();
> + scoped_ksimd() {
Why does this get brackets unlike other cases?
> + remain = sm3_base_do_update_blocks(desc, data, len, sm3_ce_transform);
> + }
> return remain;
> }
>
> static int sm3_ce_finup(struct shash_desc *desc, const u8 *data,
> unsigned int len, u8 *out)
> {
> - kernel_neon_begin();
> - sm3_base_do_finup(desc, data, len, sm3_ce_transform);
> - kernel_neon_end();
> + scoped_ksimd() {
> + sm3_base_do_finup(desc, data, len, sm3_ce_transform);
> + }
> return sm3_base_finish(desc, out);
> }
>
> diff --git a/arch/arm64/crypto/sm3-neon-glue.c b/arch/arm64/crypto/sm3-neon-glue.c
> index 6c4611a503a3..15f30cc24f32 100644
> --- a/arch/arm64/crypto/sm3-neon-glue.c
> +++ b/arch/arm64/crypto/sm3-neon-glue.c
> @@ -5,7 +5,7 @@
> * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> */
>
> -#include <asm/neon.h>
> +#include <asm/simd.h>
> #include <crypto/internal/hash.h>
> #include <crypto/sm3.h>
> #include <crypto/sm3_base.h>
> @@ -20,20 +20,16 @@ asmlinkage void sm3_neon_transform(struct sm3_state *sst, u8 const *src,
> static int sm3_neon_update(struct shash_desc *desc, const u8 *data,
> unsigned int len)
> {
> - int remain;
> -
> - kernel_neon_begin();
> - remain = sm3_base_do_update_blocks(desc, data, len, sm3_neon_transform);
> - kernel_neon_end();
> - return remain;
> + scoped_ksimd()
> + return sm3_base_do_update_blocks(desc, data, len,
> + sm3_neon_transform);
> }
>
> static int sm3_neon_finup(struct shash_desc *desc, const u8 *data,
> unsigned int len, u8 *out)
> {
> - kernel_neon_begin();
> - sm3_base_do_finup(desc, data, len, sm3_neon_transform);
> - kernel_neon_end();
> + scoped_ksimd()
> + sm3_base_do_finup(desc, data, len, sm3_neon_transform);
> return sm3_base_finish(desc, out);
> }
>