Commit Graph

7 Commits

Author SHA1 Message Date
Michael Clark
d26f5a4234
RISC-V: Change local interrupts from edge to level
This effectively changes riscv_cpu_update_mip
from edge to level. i.e. cpu_interrupt or
cpu_reset_interrupt are called regardless of
the current interrupt level.

Fixes WFI doesn't return when a IPI is issued:

- https://github.com/riscv/riscv-qemu/issues/132

To test:

1) Apply RISC-V Linux CPU hotplug patch:

- http://lists.infradead.org/pipermail/linux-riscv/2018-May/000603.html

2) Enable CONFIG_CPU_HOTPLUG in linux .config

3) Try to offline and online cpus:

  echo 1 > /sys/devices/system/cpu/cpu2/online
  echo 0 > /sys/devices/system/cpu/cpu2/online
  echo 1 > /sys/devices/system/cpu/cpu2/online

Reported-by: Atish Patra <atishp04@gmail.com>
Cc: Atish Patra <atishp04@gmail.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19 05:14:39 -07:00
Michael Clark
e3e7039cc2
RISC-V: Allow interrupt controllers to claim interrupts
We can't allow the supervisor to control SEIP as this would allow the
supervisor to clear a pending external interrupt which will result in
lost a interrupt in the case a PLIC is attached. The SEIP bit must be
hardware controlled when a PLIC is attached.

This logic was previously hard-coded so SEIP was always masked even
if no PLIC was attached. This patch adds riscv_cpu_claim_interrupts
so that the PLIC can register control of SEIP. In the case of models
without a PLIC (spike), the SEIP bit remains software controlled.

This interface allows for hardware control of supervisor timer and
software interrupts by other interrupt controller models.

Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19 05:14:39 -07:00
Michael Clark
fb73883964
RISC-V: Use riscv prefix consistently on cpu helpers
* Add riscv prefix to raise_exception function
* Add riscv prefix to CSR read/write functions
* Add riscv prefix to signal handler function
* Add riscv prefix to get fflags function
* Remove redundant declaration of riscv_cpu_init
  and rename cpu_riscv_init to riscv_cpu_init
* rename riscv_set_mode to riscv_cpu_set_mode

Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11 15:56:21 -08:00
Michael Clark
a88365c199
RISC-V: Implement existential predicates for CSRs
CSR predicate functions are added to the CSR table.
mstatus.FS and counter enable checks are moved
to predicate functions and two new predicates are
added to check misa.S for s* CSRs and a new PMP
CPU feature for pmp* CSRs.

Processors that don't implement S-mode will trap
on access to s* CSRs and processors that don't
implement PMP will trap on accesses to pmp* CSRs.

PMP checks are disabled in riscv_cpu_handle_mmu_fault
when the PMP CPU feature is not present.

Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-09 10:00:56 -08:00
Michael Clark
c7b9517188
RISC-V: Implement modular CSR helper interface
Previous CSR code uses csr_read_helper and csr_write_helper
to update CSR registers however this interface prevents
atomic read/modify/write CSR operations; in addition
there is no trap-free method to access to CSRs due
to the monolithic CSR functions call longjmp.

The current iCSR interface is not safe to be called by
target/riscv/gdbstub.c as privilege checks or missing CSRs
may call longjmp to generate exceptions. It needs to
indicate existence so traps can be generated in the
CSR instruction helpers.

This commit moves CSR access from the monolithic switch
statements in target/riscv/op_helper.c into modular
read/write functions in target/riscv/csr.c using a new
function pointer table for dispatch (which can later
be used to allow CPUs to hook up model specific CSRs).

A read/modify/write interface is added to support atomic
CSR operations and a non-trapping interface is added
to allow exception-free access to CSRs by the debugger.

The CSR functions and CSR dispatch table are ordered
to match The RISC-V Instruction Set Manual, Volume II:
Privileged Architecture Version 1.10, 2.2 CSR Listing.

An API is added to allow derived cpu instances to modify
or implement new CSR operations.

Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-08 13:59:09 -08:00
Michael Clark
9543fdaf22
RISC-V: Add hartid and \n to interrupt logging
Add carriage return that was erroneously removed
when converting to qemu_log. Change hard coded
core number to the actual hartid.

Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-20 12:08:42 -08:00
Michael Clark
df354dd410
RISC-V: Move non-ops from op_helper to cpu_helper
This patch makes op_helper.c contain only instruction
operation helpers used by translate.c and moves any
unrelated cpu helpers into cpu_helper.c. No logic is
changed by this patch.

Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-17 13:02:14 -07:00