[PATCH v3 4/5] lib: utils/irqchip: plic: Fix the off-by-one error in context save/restore helpers

[Anup Patel]

On Sun, Dec 11, 2022 at 12:24 PM Bin Meng <bmeng at tinylab.org> wrote:
>
> plic->num_src holds the number of interrupt sources without interrupt
> source 0 but the interrupt enable register includes a bit for the
> interrupt source 0 in the first word.
>
> Fixes: 415ecf28f7ad ("lib: irqchip/plic: Add context save/restore helpers")
> Signed-off-by: Bin Meng <bmeng at tinylab.org>
> Reviewed-by: Anup Patel <anup at brainfault.org>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

>
> ---
>
> (no changes since v2)
>
> Changes in v2:
> - new patch: lib: utils/irqchip: plic: Fix the off-by-one error in context save/restore helpers
>
>  lib/utils/irqchip/plic.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
> index 568f814..b152bb7 100644
> --- a/lib/utils/irqchip/plic.c
> +++ b/lib/utils/irqchip/plic.c
> @@ -100,7 +100,7 @@ static void plic_set_ie(const struct plic_data *plic, u32 cntxid,
>  void plic_context_save(const struct plic_data *plic, int context_id,
>                        u32 *enable, u32 *threshold)
>  {
> -       u32 ie_words = (plic->num_src + 31) / 32;
> +       u32 ie_words = plic->num_src / 32 + 1;
>
>         for (u32 i = 0; i < ie_words; i++)
>                 enable[i] = plic_get_ie(plic, context_id, i);
> @@ -111,7 +111,7 @@ void plic_context_save(const struct plic_data *plic, int context_id,
>  void plic_context_restore(const struct plic_data *plic, int context_id,
>                           const u32 *enable, u32 threshold)
>  {
> -       u32 ie_words = (plic->num_src + 31) / 32;
> +       u32 ie_words = plic->num_src / 32 + 1;
>
>         for (u32 i = 0; i < ie_words; i++)
>                 plic_set_ie(plic, context_id, i, enable[i]);
> --
> 2.34.1
>