Commit Graph

10 Commits

Author SHA1 Message Date
Alistair Francis
e5cc6aaeb5 hw/intc: ibex_plic: Convert the PLIC to use RISC-V CPU GPIO lines
Instead of using riscv_cpu_update_mip() let's instead use the new RISC-V
CPU GPIO lines to set the external MIP bits.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 0a76946981852f5bd15f0c37ab35b253371027a8.1630301632.git.alistair.francis@wdc.com
2021-09-21 07:56:49 +10:00
Alistair Francis
d4cad54499 hw/opentitan: Update the interrupt layout
Update the OpenTitan interrupt layout to match the latest OpenTitan
bitstreams. This involves changing the Ibex PLIC memory layout and the
UART interrupts.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: e92b696f1809c9fa4410da2e9f23c414db5a6960.1617202791.git.alistair.francis@wdc.com
2021-05-11 20:02:06 +10:00
Alistair Francis
54a581c228 intc/ibex_plic: Clear interrupts that occur during claim process
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
2020-12-17 21:56:43 -08:00
Alistair Francis
deef3d2568 intc/ibex_plic: Ensure we don't loose interrupts
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
2020-11-13 21:43:48 -08:00
Alistair Francis
3a129aea81 intc/ibex_plic: Fix some typos in the comments
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 22d2fb0d7af5ca316c67ac909926368d1bcb7cf5.1605136387.git.alistair.francis@wdc.com
2020-11-13 21:43:48 -08:00
Alistair Francis
96338fefc1 hw/intc/ibex_plic: Clear the claim register when read
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
2020-11-09 15:09:53 -08:00
Alistair Francis
01c41d15de hw/intc: ibex_plic: Honour source priorities
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>
2020-08-21 22:37:55 -07:00
Alistair Francis
224914069d hw/intc: ibex_plic: Don't allow repeat interrupts on claimed lines
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>
2020-08-21 22:37:55 -07:00
Alistair Francis
c43388bbfd hw/intc: ibex_plic: Update the pending irqs
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>
2020-08-21 22:37:55 -07:00
Alistair Francis
879f60f01c hw/intc: Initial commit of lowRISC Ibex PLIC
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>
2020-06-19 08:24:07 -07:00