powerpc/xive: Add support for IRQ domain hierarchy

This adds handlers to allocate/free IRQs in a domain hierarchy. We
could try to use xive_irq_domain_map() in xive_irq_domain_alloc() but
we rely on xive_irq_alloc_data() to set the IRQ handler data and
duplicating the code is simpler.

xive_irq_free_data() needs to be called when IRQ are freed to clear
the MMIO mappings and free the XIVE handler data, xive_irq_data
structure. This is going to be a problem with MSI domains which we
will address later.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-4-clg@kaod.org

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index dbdbbc2..420d96d 100644 (file)
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1366,7 +1366,71 @@ static void xive_irq_domain_debug_show(struct seq_file *m, struct irq_domain *d,
 }
 #endif
 
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+static int xive_irq_domain_translate(struct irq_domain *d,
+                                    struct irq_fwspec *fwspec,
+                                    unsigned long *hwirq,
+                                    unsigned int *type)
+{
+       return xive_irq_domain_xlate(d, to_of_node(fwspec->fwnode),
+                                    fwspec->param, fwspec->param_count,
+                                    hwirq, type);
+}
+
+static int xive_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+                                unsigned int nr_irqs, void *arg)
+{
+       struct irq_fwspec *fwspec = arg;
+       irq_hw_number_t hwirq;
+       unsigned int type = IRQ_TYPE_NONE;
+       int i, rc;
+
+       rc = xive_irq_domain_translate(domain, fwspec, &hwirq, &type);
+       if (rc)
+               return rc;
+
+       pr_debug("%s %d/%lx #%d\n", __func__, virq, hwirq, nr_irqs);
+
+       for (i = 0; i < nr_irqs; i++) {
+               /* TODO: call xive_irq_domain_map() */
+
+               /*
+                * Mark interrupts as edge sensitive by default so that resend
+                * actually works. Will fix that up below if needed.
+                */
+               irq_clear_status_flags(virq, IRQ_LEVEL);
+
+               /* allocates and sets handler data */
+               rc = xive_irq_alloc_data(virq + i, hwirq + i);
+               if (rc)
+                       return rc;
+
+               irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+                                             &xive_irq_chip, domain->host_data);
+               irq_set_handler(virq + i, handle_fasteoi_irq);
+       }
+
+       return 0;
+}
+
+static void xive_irq_domain_free(struct irq_domain *domain,
+                                unsigned int virq, unsigned int nr_irqs)
+{
+       int i;
+
+       pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
+
+       for (i = 0; i < nr_irqs; i++)
+               xive_irq_free_data(virq + i);
+}
+#endif
+
 static const struct irq_domain_ops xive_irq_domain_ops = {
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+       .alloc  = xive_irq_domain_alloc,
+       .free   = xive_irq_domain_free,
+       .translate = xive_irq_domain_translate,
+#endif
        .match = xive_irq_domain_match,
        .map = xive_irq_domain_map,
        .unmap = xive_irq_domain_unmap,