On Tue, Jan 15, 2019 at 9:24 PM Christoph Hellwig <h...@infradead.org> wrote:
>
> On Thu, Dec 27, 2018 at 04:48:19PM +0530, Anup Patel wrote:
> > We have two enteries (one for M-mode and another for S-mode) in the
> > interrupts-extended DT property of PLIC DT node for each HART. It is
> > expected that firmware/bootloader will set M-mode HWIRQ line of each
> > HART to 0xffffffff (i.e. -1) in interrupts-extended DT property
> > because Linux runs in S-mode only.
> >
> > If firmware/bootloader is buggy then it will not correctly update
> > interrupts-extended DT property which might result in a plic_handler
> > configured twice. This patch adds a warning in plic_init() if a
> > plic_handler is already marked present. This warning provides us
> > a hint about incorrectly updated interrupts-extended DT property.
> >
> > Signed-off-by: Anup Patel <a...@brainfault.org>
> > Reviewed-by: Christoph Hellwig <h...@lst.de>
> > ---
> > drivers/irqchip/irq-sifive-plic.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/irqchip/irq-sifive-plic.c
> > b/drivers/irqchip/irq-sifive-plic.c
> > index 01bbbbffbcae..b9a0bcefe426 100644
> > --- a/drivers/irqchip/irq-sifive-plic.c
> > +++ b/drivers/irqchip/irq-sifive-plic.c
> > @@ -229,6 +229,11 @@ static int __init plic_init(struct device_node *node,
> >
> > cpu = riscv_hartid_to_cpuid(hartid);
> > handler = per_cpu_ptr(&plic_handlers, cpu);
> > + if (handler->present) {
> > + pr_warn("handler already present for context %d.\n",
> > i);
> > + continue;
> > + }
> > +
>
> Just use WARN_ON_ONCE?
WARN_ON_ONCE() is not suitable here because we want know
all the context IDs for which handler is already present.
Regards,
Anup
