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| author | Jessica Clarke <jrtc27@jrtc27.com> | 2020-06-18 21:23:43 +0100 |
|---|---|---|
| committer | Alistair Francis <alistair.francis@wdc.com> | 2020-07-02 09:19:32 -0700 |
| commit | aa4d30f6618dcaf033c4294ca219ef17a6bae69f (patch) | |
| tree | 438874c1baf199b341fdd5c6905daf23d0758a48 /hw/riscv | |
| parent | 64f0ad8ad8e13257e7c912df470d46784b55c3fd (diff) | |
| download | qemu-aa4d30f6618dcaf033c4294ca219ef17a6bae69f.zip qemu-aa4d30f6618dcaf033c4294ca219ef17a6bae69f.tar.gz qemu-aa4d30f6618dcaf033c4294ca219ef17a6bae69f.tar.bz2 | |
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>
Diffstat (limited to 'hw/riscv')
| -rw-r--r-- | hw/riscv/sifive_plic.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c index 4f216c5..d91e82b 100644 --- a/hw/riscv/sifive_plic.c +++ b/hw/riscv/sifive_plic.c @@ -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) |