Re: [PATCH v2 2/4] xen/riscv: add csr_read_safe() helper

[Jan Beulich <jbeulich@suse.com>]

On 31.03.2026 21:04, Oleksii Kurochko wrote:
> @@ -78,6 +80,38 @@
>                             : "memory" );                        \
>  })
>  
> +static always_inline bool csr_read_safe(unsigned long csr,
> +                                        unsigned long *val)
> +{
> +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
> +    asm_inline goto (
> +        "1: csrr %[val], %[csr]\n"
> +        ASM_EXTABLE(1b, %l[fault])
> +        : [val] "=&r" (*val)

Why the & when there's only a single insn?

> +        : [csr] "i" (csr)
> +        :
> +        : fault );
> +
> +    return true;
> +
> + fault:
> +    return false;
> +#else
> +    bool allowed = false;
> +
> +    asm_inline volatile (
> +        "1: csrr %[val], %[csr]\n"
> +        "   li %[allowed], 1\n"
> +        "2:\n"
> +        ASM_EXTABLE(1b, 2b)
> +        : [val] "=&r" (*val), [allowed] "+r" (allowed)
> +        : [csr] "i" (csr)
> +        : );

Why the excess colon?

With these adjusted (again happy to do so while committing, so long
as you agree):
Reviewed-by: Jan Beulich <jbeulich@suse.com>

Jan