Hi Marc,
On Wed, Jun 25, 2014 at 10:28:45AM +0100, Marc Zyngier wrote:
> Now that we've switched to EOImode == 1, prevent a forwarded interrupt
> from being deactivated after its priority has been dropped.
>
> Also add support for the interrupt state to be saved/restored.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> drivers/irqchip/irq-gic.c | 48 +++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 42 insertions(+), 6 deletions(-)
[...]
> +static void gic_irq_set_fwd_state(struct irq_data *d, u32 val, u32 mask)
> +{
> + if (mask & IRQ_FWD_STATE_PENDING)
> + gic_poke_irq(d, (val & IRQ_FWD_STATE_PENDING) ? GIC_DIST_ENABLE_SET : GIC_DIST_ENABLE_CLEAR);
> + if (mask & IRQ_FWD_STATE_ACTIVE)
> + gic_poke_irq(d, (val & IRQ_FWD_STATE_ACTIVE) ? GIC_DIST_ACTIVE_SET : GIC_DIST_ACTIVE_CLEAR);
> + if (mask & IRQ_FWD_STATE_MASKED)
> + gic_poke_irq(d, (val & IRQ_FWD_STATE_MASKED) ? GIC_DIST_ENABLE_CLEAR : GIC_DIST_ENABLE_SET);
Given that this isn't atomic and KVM only cares about ACTIVE, why not change
mask to be a single state only? Renumbering the states so that's not bits
would help to enforce this (i.e. make IRQ_FWD_STATE_ACTIVE 0, PENDING 1,
...).
That would also allow you to switch on the state and return early.
> +static u32 gic_irq_get_fwd_state(struct irq_data *d, u32 mask)
> +{
> + u32 val = 0;
> +
> + if (mask & IRQ_FWD_STATE_PENDING && gic_peek_irq(d, GIC_DIST_ENABLE_SET))
> + val |= IRQ_FWD_STATE_PENDING;
> + if (mask & IRQ_FWD_STATE_ACTIVE && gic_peek_irq(d, GIC_DIST_ACTIVE_SET))
> + val |= IRQ_FWD_STATE_ACTIVE;
> + if (mask & IRQ_FWD_STATE_MASKED && !gic_peek_irq(d, GIC_DIST_ENABLE_SET))
> + val |= IRQ_FWD_STATE_MASKED;
*and* you could peek GIC_DIST_ENABLE_SET in one place here.
Will
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