On 7/25/20 7:34 AM, Alistair Francis wrote:
> This patch follows what commit aa4d30f6618dc "riscv: plic: Honour source
> priorities" does and ensures that the highest priority interrupt will be
> serviced first.
>
> Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
> Cc: Jessica Clarke <jrt...@jrtc27.com>
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> ---
> hw/intc/ibex_plic.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/hw/intc/ibex_plic.c b/hw/intc/ibex_plic.c
> index 669247ef08..f49fa67c91 100644
> --- a/hw/intc/ibex_plic.c
> +++ b/hw/intc/ibex_plic.c
> @@ -57,6 +57,8 @@ static void ibex_plic_irqs_set_pending(IbexPlicState *s,
> int irq, bool level)
> static bool ibex_plic_irqs_pending(IbexPlicState *s, uint32_t context)
> {
> int i;
> + uint32_t max_irq = 0;
> + uint32_t max_prio = s->threshold;
>
> for (i = 0; i < s->pending_num; i++) {
> uint32_t irq_num = ctz64(s->pending[i]) + (i * 32);
> @@ -66,14 +68,17 @@ static bool ibex_plic_irqs_pending(IbexPlicState *s,
> uint32_t context)
> continue;
> }
>
> - if (s->priority[irq_num] > s->threshold) {
> - if (!s->claim) {
> - s->claim = irq_num;
> - }
> - return true;
> + if (s->priority[irq_num] > max_prio) {
> + max_irq = irq_num;
> + max_prio = s->priority[irq_num];
> }
> }
>
> + if (max_irq) {
> + s->claim = max_irq;
> + return true;
> + }
> +
> return false;
> }
>
>
