riscv: plic: Honour source priorities

The source priorities can be used to order sources with respect to other
sources, not just as a way to enable/disable them based off a threshold.
We must therefore always claim the highest-priority source, rather than
the first source we find.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200618202343.20455-1-jrtc27@jrtc27.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
master
Jessica Clarke 2020-06-18 21:23:43 +01:00 committed by Alistair Francis
parent 64f0ad8ad8
commit aa4d30f661
1 changed files with 12 additions and 5 deletions

View File

@ -166,6 +166,9 @@ static void sifive_plic_update(SiFivePLICState *plic)
static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
{
int i, j;
uint32_t max_irq = 0;
uint32_t max_prio = plic->target_priority[addrid];
for (i = 0; i < plic->bitfield_words; i++) {
uint32_t pending_enabled_not_claimed =
(plic->pending[i] & ~plic->claimed[i]) &
@ -177,14 +180,18 @@ static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
int irq = (i << 5) + j;
uint32_t prio = plic->source_priority[irq];
int enabled = pending_enabled_not_claimed & (1 << j);
if (enabled && prio > plic->target_priority[addrid]) {
sifive_plic_set_pending(plic, irq, false);
sifive_plic_set_claimed(plic, irq, true);
return irq;
if (enabled && prio > max_prio) {
max_irq = irq;
max_prio = prio;
}
}
}
return 0;
if (max_irq) {
sifive_plic_set_pending(plic, max_irq, false);
sifive_plic_set_claimed(plic, max_irq, true);
}
return max_irq;
}
static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)