[PATCH 06/11] irqchip/gic-v3: Configure SGIs as standard interrupts

[Marc Zyngier]

Change the way we deal with GICv3 SGIs by turning them into proper
IRQs, and calling into the arch code to register the interrupt range
instead of a callback.

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
 drivers/irqchip/irq-gic-v3.c | 91 +++++++++++++++++++++---------------
 1 file changed, 53 insertions(+), 38 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 23d7c87da407..d57289057b75 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -36,6 +36,9 @@
 #define FLAGS_WORKAROUND_GICR_WAKER_MSM8996	(1ULL << 0)
 #define FLAGS_WORKAROUND_CAVIUM_ERRATUM_38539	(1ULL << 1)
 
+#define GIC_IRQ_TYPE_PARTITION	(GIC_IRQ_TYPE_LPI + 1)
+#define GIC_IRQ_TYPE_SGI	(GIC_IRQ_TYPE_LPI + 2)
+
 struct redist_region {
 	void __iomem		*redist_base;
 	phys_addr_t		phys_base;
@@ -657,38 +660,14 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
 	if ((irqnr >= 1020 && irqnr <= 1023))
 		return;
 
-	/* Treat anything but SGIs in a uniform way */
-	if (likely(irqnr > 15)) {
-		int err;
-
-		if (static_branch_likely(&supports_deactivate_key))
-			gic_write_eoir(irqnr);
-		else
-			isb();
-
-		err = handle_domain_irq(gic_data.domain, irqnr, regs);
-		if (err) {
-			WARN_ONCE(true, "Unexpected interrupt received!\n");
-			gic_deactivate_unhandled(irqnr);
-		}
-		return;
-	}
-	if (irqnr < 16) {
+	if (static_branch_likely(&supports_deactivate_key))
 		gic_write_eoir(irqnr);
-		if (static_branch_likely(&supports_deactivate_key))
-			gic_write_dir(irqnr);
-#ifdef CONFIG_SMP
-		/*
-		 * Unlike GICv2, we don't need an smp_rmb() here.
-		 * The control dependency from gic_read_iar to
-		 * the ISB in gic_write_eoir is enough to ensure
-		 * that any shared data read by handle_IPI will
-		 * be read after the ACK.
-		 */
-		handle_IPI(irqnr, regs);
-#else
-		WARN_ONCE(true, "Unexpected SGI received!\n");
-#endif
+	else
+		isb();
+
+	if (handle_domain_irq(gic_data.domain, irqnr, regs)) {
+		WARN_ONCE(true, "Unexpected interrupt received!\n");
+		gic_deactivate_unhandled(irqnr);
 	}
 }
 
@@ -1136,11 +1115,11 @@ static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
 	gic_write_sgi1r(val);
 }
 
-static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
+static void gic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask)
 {
 	int cpu;
 
-	if (WARN_ON(irq >= 16))
+	if (WARN_ON(d->hwirq >= 16))
 		return;
 
 	/*
@@ -1154,7 +1133,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 		u16 tlist;
 
 		tlist = gic_compute_target_list(&cpu, mask, cluster_id);
-		gic_send_sgi(cluster_id, tlist, irq);
+		gic_send_sgi(cluster_id, tlist, d->hwirq);
 	}
 
 	/* Force the above writes to ICC_SGI1R_EL1 to be executed */
@@ -1163,10 +1142,36 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 
 static void gic_smp_init(void)
 {
-	set_smp_cross_call(gic_raise_softirq);
+	struct irq_fwspec sgi_fwspec = {
+		.fwnode		= gic_data.fwnode,
+	};
+	int base_sgi;
+
 	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
 				  "irqchip/arm/gicv3:starting",
 				  gic_starting_cpu, NULL);
+
+	if (is_of_node(gic_data.fwnode)) {
+		/* DT */
+		sgi_fwspec.param_count = 3;
+		sgi_fwspec.param[0] = GIC_IRQ_TYPE_SGI;
+		sgi_fwspec.param[1] = 0;
+		sgi_fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+	} else {
+		/* ACPI */
+		sgi_fwspec.param_count = 2;
+		sgi_fwspec.param[0] = 0;
+		sgi_fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+	}
+
+	/* Register all 8 non-secure SGIs */
+	base_sgi = __irq_domain_alloc_irqs(gic_data.domain, -1, 8,
+					   NUMA_NO_NODE, &sgi_fwspec,
+					   false, NULL);
+	if (WARN_ON(base_sgi <= 0))
+		return;
+
+	set_smp_ipi_range(base_sgi, 8);
 }
 
 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
@@ -1215,6 +1220,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 }
 #else
 #define gic_set_affinity	NULL
+#define gic_ipi_send_mask	NULL
 #define gic_smp_init()		do { } while(0)
 #endif
 
@@ -1257,6 +1263,7 @@ static struct irq_chip gic_chip = {
 	.irq_set_irqchip_state	= gic_irq_set_irqchip_state,
 	.irq_nmi_setup		= gic_irq_nmi_setup,
 	.irq_nmi_teardown	= gic_irq_nmi_teardown,
+	.ipi_send_mask		= gic_ipi_send_mask,
 	.flags			= IRQCHIP_SET_TYPE_MASKED |
 				  IRQCHIP_SKIP_SET_WAKE |
 				  IRQCHIP_MASK_ON_SUSPEND,
@@ -1289,6 +1296,13 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 
 	switch (__get_intid_range(hw)) {
 	case SGI_RANGE:
+		irq_set_percpu_devid(irq);
+		irq_domain_set_info(d, irq, hw, chip, d->host_data,
+				    handle_percpu_devid_fasteoi_ipi,
+				    NULL, NULL);
+		irq_set_status_flags(irq, IRQ_NOAUTOEN);
+		break;
+
 	case PPI_RANGE:
 	case EPPI_RANGE:
 		irq_set_percpu_devid(irq);
@@ -1319,8 +1333,6 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 	return 0;
 }
 
-#define GIC_IRQ_TYPE_PARTITION	(GIC_IRQ_TYPE_LPI + 1)
-
 static int gic_irq_domain_translate(struct irq_domain *d,
 				    struct irq_fwspec *fwspec,
 				    unsigned long *hwirq,
@@ -1353,6 +1365,9 @@ static int gic_irq_domain_translate(struct irq_domain *d,
 			else
 				*hwirq += 16;
 			break;
+		case GIC_IRQ_TYPE_SGI:
+			*hwirq = fwspec->param[1];
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -1657,9 +1672,9 @@ static int __init gic_init_bases(void __iomem *dist_base,
 
 	gic_update_rdist_properties();
 
-	gic_smp_init();
 	gic_dist_init();
 	gic_cpu_init();
+	gic_smp_init();
 	gic_cpu_pm_init();
 
 	if (gic_dist_supports_lpis()) {
-- 
2.26.2