[PATCH 07/16] irqchip/mips-gic: clean up IRQ domain creation failure

[Haofeng Li]

From: Haofeng Li <lihaofeng@xxxxxxxxxx>

After mapping the register base, irq_domain_create_simple() failure
returns without unmapping it.

The CPU chained or VEIC handler is also installed before either IRQ
domain is ready. Unmapping the registers while that handler remains
published would leave a path to unmapped MMIO, and a later IPI domain
failure would expose a half-initialized controller.

Unmap and clear the register base when primary domain creation fails,
and publish the CPU interrupt handler only after both domains have
been created successfully.

Fixes: fbea754123ae ("irqchip: mips-gic: Inline __gic_init()")

Signed-off-by: Haofeng Li <lihaofeng@xxxxxxxxxx>
---
 drivers/irqchip/irq-mips-gic.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 19a57c5e2b2e..85fe0d8a34c5 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -956,23 +956,14 @@ static int __init gic_of_init(struct device_node *node,
 	gic_shared_intrs = FIELD_GET(GIC_CONFIG_NUMINTERRUPTS, gicconfig);
 	gic_shared_intrs = (gic_shared_intrs + 1) * 8;
 
-	if (cpu_has_veic) {
-		/* Always use vector 1 in EIC mode */
-		gic_cpu_pin = 0;
-		set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET,
-			       __gic_irq_dispatch);
-	} else {
-		gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET;
-		irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec,
-					gic_irq_dispatch);
-	}
-
 	gic_irq_domain = irq_domain_create_simple(of_fwnode_handle(node),
 						  GIC_NUM_LOCAL_INTRS +
 						  gic_shared_intrs, 0,
 						  &gic_irq_domain_ops, NULL);
 	if (!gic_irq_domain) {
 		pr_err("Failed to add IRQ domain");
+		iounmap(mips_gic_base);
+		mips_gic_base = NULL;
 		return -ENXIO;
 	}
 
@@ -980,6 +971,17 @@ static int __init gic_of_init(struct device_node *node,
 	if (ret)
 		return ret;
 
+	if (cpu_has_veic) {
+		/* Always use vector 1 in EIC mode */
+		gic_cpu_pin = 0;
+		set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET,
+			       __gic_irq_dispatch);
+	} else {
+		gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET;
+		irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec,
+					gic_irq_dispatch);
+	}
+
 	board_bind_eic_interrupt = &gic_bind_eic_interrupt;
 
 	/*
-- 
2.25.1