Currently, if IRQ number != RISCV_MACHINE_TIMER_IRQ (only device IRQ in qemu),
riscv32-qemu was considering the IRQ as an exception. However, fake IRQs
can also be generated by setting corresponding bits in the Machine Interrupt
Pending register (mip). With the current implementation, these IRQs were
considered as unexpected exceptions.
To circumvent the problem, update the IRQ filtering mechanism by considering
an IRQ (IRQ number as reported by the mcause register) as an exception only
if its corresponding bit is NOT set in the mip register.
Change-Id: I4c581a84d83ee0ba2c4ea35f89ba732401eb8fa4
Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
be856d4b13