Previously if an interrupt occured during the claim process (after the
interrupt is claimed but before it's completed) it would never be
cleared.
This patch ensures that we also clear the hidden_pending bits as well.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Jackie Ke <jackieke724@hotmail.com>
Message-id: 4e9786084a86f220689123cc8a7837af8fa071cf.1607100423.git.alistair.francis@wdc.com
If an interrupt occurs between when we claim and complete an interrupt
we currently drop the interrupt in ibex_plic_irqs_set_pending(). This
somewhat matches hardware that also ignore the interrupt between the
claim and complete process.
In the case of hardware though the physical interrupt line will still
be asserted after we have completed the interrupt. This means we will
still act on the interrupt after the complete process. In QEMU we don't
and instead we drop the interrupt as it is never recorded.
This patch changed the behaviour of the Ibex PLIC so that we save all
interrupts that occur while we are between claiming and completing an
interrupt so that we can act on them after the completition process.
This fixes interrupts being dropped when running Tock on OpenTitain in
QEMU.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: e7bcf98c6925b1e6e7828e7c3f85293a09a65b12.1605136387.git.alistair.francis@wdc.com
After claiming the interrupt by reading the claim register we want to
clear the register to make sure the interrupt doesn't appear at the next
read.
This matches the documentation for the claim register as when an interrupt
is claimed by a target the relevant bit of IP is cleared (which we already
do): https://docs.opentitan.org/hw/ip/rv_plic/doc/index.html
This also matches the current hardware.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 68d4575deef2559b7a747f3bda193fcf43af4558.1604629928.git.alistair.francis@wdc.com
This patch follows what commit aa4d30f661 "riscv: plic: Honour source
priorities" does and ensures that the highest priority interrupt will be
serviced first.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Cc: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <a697ca8a31eff8eb18a88e09a28206063cf85d48.1595655188.git.alistair.francis@wdc.com>
Once an interrupt has been claimed, but before it has been compelted we
shouldn't receive any more pending interrupts. This patche keeps track
of this to ensure that we don't see any more interrupts until it is
completed.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <394c3f070615ff2b4fab61a1cf9cb48c122913b7.1595655188.git.alistair.francis@wdc.com>
After a claim or a priority change we need to update the pending
interrupts. This is based on the same patch for the SiFive PLIC:
5576582280 "riscv: plic: Add a couple of mising
sifive_plic_update calls"
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Cc: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <0693aa700a4c67c49b3f1c973a82b257fdb7198d.1595655188.git.alistair.francis@wdc.com>
The Ibex core contains a PLIC that although similar to the RISC-V spec
is not RISC-V spec compliant.
This patch implements a Ibex PLIC in a somewhat generic way.
As the current RISC-V PLIC needs tidying up, my hope is that as the Ibex
PLIC move towards spec compliance this PLIC implementation can be
updated until it can replace the current PLIC.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
