[PATCH] lib: sbi: Fix shift bug in sbi_system_reset

[Anup Patel]

On Thu, Dec 21, 2023 at 7:14 AM Xiang W <wxjstz at 126.com> wrote:
>
> There is a problem with judging whether the current hart belongs to
> hmask. If cur_hartid minus hbase is greater than BITS_PER_LONG, the
> previous hmask will also have a bit cleared incorrectly, which will
> cause some harts to lose ipi.
>
> Signed-off-by: Xiang W <wxjstz at 126.com>
> ---
>  lib/sbi/sbi_system.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/sbi/sbi_system.c b/lib/sbi/sbi_system.c
> index d1fa349..e930272 100644
> --- a/lib/sbi/sbi_system.c
> +++ b/lib/sbi/sbi_system.c
> @@ -72,7 +72,8 @@ void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
>
>         /* Send HALT IPI to every hart other than the current hart */
>         while (!sbi_hsm_hart_interruptible_mask(dom, hbase, &hmask)) {
> -               if (hbase <= cur_hartid)
> +               if ((hbase <= cur_hartid)
> +                         && (cur_hartid < hbase + BITS_PER_LONG))

If "cur_hartid < hbase + BITS_PER_LONG" then
"1UL << (cur_hartid - hbase) == 0x0" so hmask
won't be impacted.

Do we still need this additional check ?

>                         hmask &= ~(1UL << (cur_hartid - hbase));
>                 if (hmask)
>                         sbi_ipi_send_halt(hmask, hbase);
> --
> 2.43.0
>
>
> --
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Regards,
Anup