From aa4d30f6618dcaf033c4294ca219ef17a6bae69f Mon Sep 17 00:00:00 2001 From: Jessica Clarke Date: Thu, 18 Jun 2020 21:23:43 +0100 Subject: 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 Reviewed-by: Alistair Francis Message-Id: <20200618202343.20455-1-jrtc27@jrtc27.com> Signed-off-by: Alistair Francis --- hw/riscv/sifive_plic.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'hw') 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) -- cgit v1.1 From 55765822804f5a58594e0931e0fb8f80337b5425 Mon Sep 17 00:00:00 2001 From: Jessica Clarke Date: Thu, 18 Jun 2020 22:06:49 +0100 Subject: riscv: plic: Add a couple of mising sifive_plic_update calls Claiming an interrupt and changing the source priority both potentially affect whether an interrupt is pending, thus we must re-compute xEIP. Note that we don't put the sifive_plic_update inside sifive_plic_claim so that the logging of a claim (and the resulting IRQ) happens before the state update, making the causal effect clear, and that we drop the explicit call to sifive_plic_print_state when claiming since sifive_plic_update already does that automatically at the end for us. This can result in both spurious interrupt storms if you fail to complete an IRQ before enabling interrupts (and no other actions occur that result in a call to sifive_plic_update), but also more importantly lost interrupts if a disabled interrupt is pending and then becomes enabled. Signed-off-by: Jessica Clarke Reviewed-by: Alistair Francis Message-Id: <20200618210649.22451-1-jrtc27@jrtc27.com> Signed-off-by: Alistair Francis --- hw/riscv/sifive_plic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'hw') diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c index d91e82b..c20c192 100644 --- a/hw/riscv/sifive_plic.c +++ b/hw/riscv/sifive_plic.c @@ -255,8 +255,8 @@ static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size) plic->addr_config[addrid].hartid, mode_to_char(plic->addr_config[addrid].mode), value); - sifive_plic_print_state(plic); } + sifive_plic_update(plic); return value; } } @@ -287,6 +287,7 @@ static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value, qemu_log("plic: write priority: irq=%d priority=%d\n", irq, plic->source_priority[irq]); } + sifive_plic_update(plic); return; } else if (addr >= plic->pending_base && /* 1 bit per source */ addr < plic->pending_base + (plic->num_sources >> 3)) -- cgit v1.1 From 70b78d4e71494c90d2ccb40381336bc9b9a22f79 Mon Sep 17 00:00:00 2001 From: Alistair Francis Date: Tue, 30 Jun 2020 13:12:11 -0700 Subject: hw/riscv: Allow 64 bit access to SiFive CLINT Commit 5d971f9e672507210e77d020d89e0e89165c8fc9 "memory: Revert "memory: accept mismatching sizes in memory_region_access_valid"" broke most RISC-V boards as they do 64 bit accesses to the CLINT and QEMU would trigger a fault. Fix this failure by allowing 8 byte accesses. Signed-off-by: Alistair Francis Reviewed-by: LIU Zhiwei Message-Id: <122b78825b077e4dfd39b444d3a46fe894a7804c.1593547870.git.alistair.francis@wdc.com> --- hw/riscv/sifive_clint.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'hw') diff --git a/hw/riscv/sifive_clint.c b/hw/riscv/sifive_clint.c index b11ffa0..669c21a 100644 --- a/hw/riscv/sifive_clint.c +++ b/hw/riscv/sifive_clint.c @@ -181,7 +181,7 @@ static const MemoryRegionOps sifive_clint_ops = { .endianness = DEVICE_LITTLE_ENDIAN, .valid = { .min_access_size = 4, - .max_access_size = 4 + .max_access_size = 8 } }; -- cgit v1.1