On Tue, 4 Nov 2014, Jiang Liu wrote:
> +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
> +static inline irq_hw_number_t
> +msi_get_hwirq(struct pci_dev *pdev, struct msi_desc *msidesc)
> +{
> + return (irq_hw_number_t)msidesc->msi_attrib.entry_nr |
> + PCI_DEVID(pdev->bus->number, pdev->devfn) << 11 |
> + (pci_domain_nr(pdev->bus) & 0xFFFFFFFF) << 27;
> +}
> +
> +static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *arg)
> +{
> + int i, ret;
> + irq_hw_number_t hwirq = arch_msi_irq_domain_get_hwirq(arg);
> +
> + if (irq_find_mapping(domain, hwirq) > 0)
> + return -EEXIST;
> +
> + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
> + if (ret >= 0)
> + for (i = 0; i < nr_irqs; i++) {
> + irq_domain_set_hwirq_and_chip(domain, virq + i,
> + hwirq + i, &msi_chip, (void *)(long)i);
I think msi_chip being a global unique thing is problematic. It does
not allow multi platform kernels to select a chip at boot time and it
does not allow per domain chip implementations when you have multiple
msi domains. Aside of that msi_chip is a pretty bad name for a global.
The solution is rather simple and msi is wide spread enough to justify
that.
struct irqdomain_msi_data {
struct irq_chip *irq_chip;
};
We make that a struct so we can accomodate for other special things
which might be domain rather than architecture specific. One
obvious use case would be to hold the arch_msi_irq_domain_get/set_hwirq
callbacks.
struct irq_domain *msi_create_irq_domain(struct irq_domain *parent,
struct irqdomain_msi_data *data)
{
struct irq_domain *domain;
domain = irq_domain_add_tree(NULL, &msi_domain_ops, NULL);
if (domain) {
domain->parent = parent;
domain->msi_data = data;
}
return domain;
}
Now the above becomes:
struct irq_chip *msi_chip = domain->msi_data->irq_chip;
irq_domain_set_hwirq_and_chip(domain, virq + i,
hwirq + i, msi_chip, (void *)(long)i);
> +int msi_irq_domain_alloc_irqs(struct irq_domain *domain, int type,
> + struct pci_dev *dev, void *arg)
> +{
> + int i, virq;
> + struct msi_desc *msidesc;
> + int node = dev_to_node(&dev->dev);
> +
> + list_for_each_entry(msidesc, &dev->msi_list, list) {
> + arch_msi_irq_domain_set_hwirq(arg, msi_get_hwirq(dev, msidesc));
The arch_xxx callbacks want to be documented. It's not obvious what
they are supposed to do.
Thanks,
tglx
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