irqchip/gic-v3: Configure SGIs as standard interrupts

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.
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

drivers/irqchip/irq-gic-v3.c

@@ -36,6 +36,8 @@
 #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)
+
 struct redist_region {
 	void __iomem		*redist_base;
 	phys_addr_t		phys_base;
@@ -383,7 +385,7 @@ static int gic_irq_set_irqchip_state(struct irq_data *d,
 {
 	u32 reg;
 
-	if (d->hwirq >= 8192) /* PPI/SPI only */
+	if (d->hwirq >= 8192) /* SGI/PPI/SPI only */
 		return -EINVAL;
 
 	switch (which) {
@@ -550,12 +552,12 @@ static int gic_set_type(struct irq_data *d, unsigned int type)
 	u32 offset, index;
 	int ret;
 
-	/* Interrupt configuration for SGIs can't be changed */
-	if (irq < 16)
-		return -EINVAL;
-
 	range = get_intid_range(d);
 
+	/* Interrupt configuration for SGIs can't be changed */
+	if (range == SGI_RANGE)
+		return type != IRQ_TYPE_EDGE_RISING ? -EINVAL : 0;
+
 	/* SPIs have restrictions on the supported types */
 	if ((range == SPI_RANGE || range == ESPI_RANGE) &&
 	    type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
@@ -583,6 +585,9 @@ static int gic_set_type(struct irq_data *d, unsigned int type)
 
 static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
 {
+	if (get_intid_range(d) == SGI_RANGE)
+		return -EINVAL;
+
 	if (vcpu)
 		irqd_set_forwarded_to_vcpu(d);
 	else
@@ -657,39 +662,15 @@ 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) {
+	if (handle_domain_irq(gic_data.domain, irqnr, regs)) {
 		WARN_ONCE(true, "Unexpected interrupt received!\n");
 		gic_deactivate_unhandled(irqnr);
 	}
-		return;
-	}
-	if (irqnr < 16) {
-		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
-	}
 }
 
 static u32 gic_get_pribits(void)
@@ -1136,11 +1117,11 @@ 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 +1135,7 @@ 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 +1144,24 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 
 static void __init gic_smp_init(void)
 {
-	set_smp_cross_call(gic_raise_softirq);
+	struct irq_fwspec sgi_fwspec = {
+		.fwnode		= gic_data.fwnode,
+		.param_count	= 1,
+	};
+	int base_sgi;
+
 	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
 				  "irqchip/arm/gicv3:starting",
 				  gic_starting_cpu, NULL);
+
+	/* 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 +1210,7 @@ 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 +1253,7 @@ 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,
@@ -1274,6 +1271,7 @@ static struct irq_chip gic_eoimode1_chip = {
 	.irq_set_vcpu_affinity	= gic_irq_set_vcpu_affinity,
 	.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 +1287,12 @@ 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);
+		break;
+
 	case PPI_RANGE:
 	case EPPI_RANGE:
 		irq_set_percpu_devid(irq);
@@ -1318,13 +1322,17 @@ 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,
 				    unsigned int *type)
 {
+	if (fwspec->param_count == 1 && fwspec->param[0] < 16) {
+		*hwirq = fwspec->param[0];
+		*type = IRQ_TYPE_EDGE_RISING;
+		return 0;
+	}
+
 	if (is_of_node(fwspec->fwnode)) {
 		if (fwspec->param_count < 3)
 			return -EINVAL;
@@ -1656,9 +1664,9 @@ 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()) {