[PATCH 2/5] powerpc/xive: Introduce an IPI interrupt domain

[Cédric Le Goater]

The IPI interrupt is a special case of the XIVE IRQ domain. When
mapping and unmapping the interrupts in the Linux interrupt number
space, the HW interrupt number 0 (XIVE_IPI_HW_IRQ) is checked to
distinguish the IPI interrupt from other interrupts of the system.

Simplify the XIVE interrupt domain by introducing a specific domain
for the IPI.

Signed-off-by: Cédric Le Goater <clg at kaod.org>
---
 arch/powerpc/sysdev/xive/common.c | 51 +++++++++++++------------------
 1 file changed, 22 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 776871274b69..4aceac0f3046 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -63,6 +63,8 @@ static const struct xive_ops *xive_ops;
 static struct irq_domain *xive_irq_domain;
 
 #ifdef CONFIG_SMP
+static struct irq_domain *xive_ipi_irq_domain;
+
 /* The IPIs all use the same logical irq number */
 static u32 xive_ipi_irq;
 #endif
@@ -1068,20 +1070,32 @@ static struct irq_chip xive_ipi_chip = {
 	.irq_unmask = xive_ipi_do_nothing,
 };
 
+/*
+ * IPIs are marked per-cpu. We use separate HW interrupts under the
+ * hood but associated with the same "linux" interrupt
+ */
+static int xive_ipi_irq_domain_map(struct irq_domain *h, unsigned int virq,
+				   irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &xive_ipi_chip, handle_percpu_irq);
+	return 0;
+}
+
+static const struct irq_domain_ops xive_ipi_irq_domain_ops = {
+	.map = xive_ipi_irq_domain_map,
+};
+
 static void __init xive_request_ipi(void)
 {
 	unsigned int virq;
 
-	/*
-	 * Initialization failed, move on, we might manage to
-	 * reach the point where we display our errors before
-	 * the system falls appart
-	 */
-	if (!xive_irq_domain)
+	xive_ipi_irq_domain = irq_domain_add_linear(NULL, 1,
+						    &xive_ipi_irq_domain_ops, NULL);
+	if (WARN_ON(xive_ipi_irq_domain == NULL))
 		return;
 
 	/* Initialize it */
-	virq = irq_create_mapping(xive_irq_domain, XIVE_IPI_HW_IRQ);
+	virq = irq_create_mapping(xive_ipi_irq_domain, XIVE_IPI_HW_IRQ);
 	xive_ipi_irq = virq;
 
 	WARN_ON(request_irq(virq, xive_muxed_ipi_action,
@@ -1179,19 +1193,6 @@ static int xive_irq_domain_map(struct irq_domain *h, unsigned int virq,
 	 */
 	irq_clear_status_flags(virq, IRQ_LEVEL);
 
-#ifdef CONFIG_SMP
-	/* IPIs are special and come up with HW number 0 */
-	if (hw == XIVE_IPI_HW_IRQ) {
-		/*
-		 * IPIs are marked per-cpu. We use separate HW interrupts under
-		 * the hood but associated with the same "linux" interrupt
-		 */
-		irq_set_chip_and_handler(virq, &xive_ipi_chip,
-					 handle_percpu_irq);
-		return 0;
-	}
-#endif
-
 	rc = xive_irq_alloc_data(virq, hw);
 	if (rc)
 		return rc;
@@ -1203,15 +1204,7 @@ static int xive_irq_domain_map(struct irq_domain *h, unsigned int virq,
 
 static void xive_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
 {
-	struct irq_data *data = irq_get_irq_data(virq);
-	unsigned int hw_irq;
-
-	/* XXX Assign BAD number */
-	if (!data)
-		return;
-	hw_irq = (unsigned int)irqd_to_hwirq(data);
-	if (hw_irq != XIVE_IPI_HW_IRQ)
-		xive_irq_free_data(virq);
+	xive_irq_free_data(virq);
 }
 
 static int xive_irq_domain_xlate(struct irq_domain *h, struct device_node *ct,
-- 
2.26.2