On Mon, Feb 25, 2019 at 01:10:12PM +1100, David Gibson wrote:
> On Fri, Feb 22, 2019 at 12:28:28PM +0100, Cédric Le Goater wrote:
> > + /*
> > + * If the source doesn't already have an IPI, allocate
> > + * one and get the corresponding data
> > + */
> > + if (!state->ipi_number) {
> > + state->ipi_number = xive_native_alloc_irq();
> > + if (state->ipi_number == 0) {
> > + pr_err("Failed to allocate IRQ !\n");
> > + return -ENXIO;
> > + }
> > + xive_native_populate_irq_data(state->ipi_number,
> > + &state->ipi_data);
> > + pr_debug("%s allocated hw_irq=0x%x for irq=0x%lx\n", __func__,
> > + state->ipi_number, irq);
> > + }
> > +
> > + arch_spin_lock(&sb->lock);
>
> Why the direct call to arch_spin_lock() rather than just spin_lock()?
He's sharing data structures with the xics-on-xive code, and that code
has a real-mode variant, and in real mode we don't want to risk
invoking lockdep code. Hence sb->lock is an arch_spinlock_t, and he
has to use arch_spin_lock() on it.
Paul.
