Re: [PATCH 1/6] irqchip: add the Alpine MSIX interrupt controller

From: Thomas Gleixner
Date: Mon Feb 08 2016 - 05:33:08 EST


Antoine,

On Mon, 8 Feb 2016, Antoine Tenart wrote:
> +static int alpine_msix_set_affinity(struct irq_data *irq_data,
> + const struct cpumask *mask, bool force)
> +{
> + int ret;
> +
> + ret = irq_chip_set_affinity_parent(irq_data, mask, force);
> + return ret == IRQ_SET_MASK_OK ? IRQ_SET_MASK_OK_DONE : ret;

What's the point of this exercise? Why can't you just set the affinity
callback to irq_chip_set_affinity_parent() ?

> +static struct irq_chip alpine_msix_irq_chip = {
> + .name = "MSIx",
> + .irq_mask = alpine_msix_mask_msi_irq,
> + .irq_unmask = alpine_msix_unmask_msi_irq,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_set_affinity = alpine_msix_set_affinity,
> +};
> +
> +static int alpine_msix_allocate_sgi(struct alpine_msix_data *priv, int num_req)
> +{
> + int first, i;
> +
> + spin_lock(&priv->msi_map_lock);
> +
> + first = bitmap_find_next_zero_area(priv->msi_map, priv->num_spis, 0,
> + num_req, 0);
> + if (first >= priv->num_spis) {
> + spin_unlock(&priv->msi_map_lock);
> + return -ENOSPC;
> + }
> +
> + for (i = 0; i < num_req; i++)
> + set_bit(first + i, priv->msi_map);

bitmap_set() ??

> +
> + spin_unlock(&priv->msi_map_lock);
> +
> + return priv->spi_first + first;
> +}
> +
> +static void alpine_msix_free_sgi(struct alpine_msix_data *priv, unsigned sgi,
> + int num_req)
> +{
> + int i, first;
> +
> + first = sgi - priv->spi_first;
> +
> + spin_lock(&priv->msi_map_lock);
> +
> + for (i = 0; i < num_req; i++)
> + clear_bit(first + i, priv->msi_map);

bitmap_clear() ??

> + spin_unlock(&priv->msi_map_lock);
> +}

Thanks,

tglx