Re: [PATCH v2 2/2] LoongArch: Batch icache maintenance for jump_label

[Huacai Chen]

Applied, thanks.


Huacai

On Sun, Apr 5, 2026 at 10:13 AM Youling Tang <youling.tang@xxxxxxxxx> wrote:
>
> From: Youling Tang <tangyouling@xxxxxxxxxx>
>
> Switch to the batched version of the jump label update functions so
> instruction cache maintenance is deferred until the end of the update.
>
> Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxx>
> ---
>  arch/loongarch/include/asm/jump_label.h |  1 +
>  arch/loongarch/kernel/inst.c            |  6 +++---
>  arch/loongarch/kernel/jump_label.c      | 13 +++++++++++--
>  3 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/jump_label.h b/arch/loongarch/include/asm/jump_label.h
> index dcaecf69ea5a..ceb3dfa66188 100644
> --- a/arch/loongarch/include/asm/jump_label.h
> +++ b/arch/loongarch/include/asm/jump_label.h
> @@ -13,6 +13,7 @@
>  #include <linux/stringify.h>
>  #include <asm/asm.h>
>
> +#define HAVE_JUMP_LABEL_BATCH
>  #define JUMP_LABEL_NOP_SIZE    4
>
>  #ifdef CONFIG_32BIT
> diff --git a/arch/loongarch/kernel/inst.c b/arch/loongarch/kernel/inst.c
> index 1a728082944c..0b9228b7c13a 100644
> --- a/arch/loongarch/kernel/inst.c
> +++ b/arch/loongarch/kernel/inst.c
> @@ -209,6 +209,9 @@ int larch_insn_write(void *addr, u32 insn)
>         int ret;
>         unsigned long flags = 0;
>
> +       if ((unsigned long)addr & 3)
> +               return -EINVAL;
> +
>         raw_spin_lock_irqsave(&patch_lock, flags);
>         ret = copy_to_kernel_nofault(addr, &insn, LOONGARCH_INSN_SIZE);
>         raw_spin_unlock_irqrestore(&patch_lock, flags);
> @@ -221,9 +224,6 @@ int larch_insn_patch_text(void *addr, u32 insn)
>         int ret;
>         u32 *tp = addr;
>
> -       if ((unsigned long)tp & 3)
> -               return -EINVAL;
> -
>         ret = larch_insn_write(tp, insn);
>         if (!ret)
>                 flush_icache_range((unsigned long)tp,
> diff --git a/arch/loongarch/kernel/jump_label.c b/arch/loongarch/kernel/jump_label.c
> index 31891214b767..f5a394bdb5f3 100644
> --- a/arch/loongarch/kernel/jump_label.c
> +++ b/arch/loongarch/kernel/jump_label.c
> @@ -6,9 +6,11 @@
>   */
>  #include <linux/kernel.h>
>  #include <linux/jump_label.h>
> +#include <asm/cacheflush.h>
>  #include <asm/inst.h>
>
> -void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type)
> +bool arch_jump_label_transform_queue(struct jump_entry *entry,
> +                                    enum jump_label_type type)
>  {
>         u32 insn;
>         void *addr = (void *)jump_entry_code(entry);
> @@ -18,5 +20,12 @@ void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type ty
>         else
>                 insn = larch_insn_gen_nop();
>
> -       larch_insn_patch_text(addr, insn);
> +       larch_insn_write(addr, insn);
> +
> +       return true;
> +}
> +
> +void arch_jump_label_transform_apply(void)
> +{
> +       flush_icache_all();
>  }
> --
> 2.43.0
>