Re: [PATCH] powerpc/mpic: Disable preemption when calling mpic_processor_id()

[Kumar Gala <galak@kernel.crashing.org>]

On Sep 26, 2013, at 7:18 PM, Scott Wood wrote:

> Otherwise, we get a debug traceback due to the use of
> smp_processor_id() (or get_paca()) inside hard_smp_processor_id().
> mpic_host_map() is just looking for a default CPU, so it doesn't =
matter
> if we migrate after getting the CPU ID.
>=20
> Signed-off-by: Scott Wood <scottwood@freescale.com>
> ---
> arch/powerpc/sysdev/mpic.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>=20
> diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
> index 1be54fa..bdcb858 100644
> --- a/arch/powerpc/sysdev/mpic.c
> +++ b/arch/powerpc/sysdev/mpic.c
> @@ -1088,8 +1088,14 @@ static int mpic_host_map(struct irq_domain *h, =
unsigned int virq,
> 	 * is done here.
> 	 */
> 	if (!mpic_is_ipi(mpic, hw) && (mpic->flags & MPIC_NO_RESET)) {
> +		int cpu;
> +
> +		preempt_disable();
> +		cpu =3D mpic_processor_id(mpic);
> +		preempt_enable();
> +

Any reason you didn't stick this inside of mpic_processor_id() ?

> 		mpic_set_vector(virq, hw);
> -		mpic_set_destination(virq, mpic_processor_id(mpic));
> +		mpic_set_destination(virq, cpu);
> 		mpic_irq_set_priority(virq, 8);
> 	}
>=20
> --=20
> 1.8.1.2
>=20
>=20
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