x86, io_apic: Convert setup_ioapic_entry to function pointer

This pointer is changed to a different function when IRQ
remapping is enabled.
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/include/asm/io_apic.h

@@ -149,6 +149,10 @@ extern int io_apic_set_pci_routing(struct device *dev, int irq,
 void setup_IO_APIC_irq_extra(u32 gsi);
 extern void ioapic_insert_resources(void);
 
+extern int native_setup_ioapic_entry(int, struct IO_APIC_route_entry *,
+				     unsigned int, int,
+				     struct io_apic_irq_attr *);
+
 int io_apic_setup_irq_pin_once(unsigned int irq, int node, struct io_apic_irq_attr *attr);
 
 extern int save_ioapic_entries(void);
@@ -232,6 +236,7 @@ static inline void disable_ioapic_support(void) { }
 #define native_disable_io_apic		NULL
 #define native_io_apic_print_entries	NULL
 #define native_ioapic_set_affinity	NULL
+#define native_setup_ioapic_entry	NULL
 #endif
 
 #endif /* _ASM_X86_IO_APIC_H */

arch/x86/include/asm/x86_init.h

@@ -190,6 +190,8 @@ struct x86_msi_ops {
 	int  (*setup_hpet_msi)(unsigned int irq, unsigned int id);
 };
 
+struct IO_APIC_route_entry;
+struct io_apic_irq_attr;
 struct irq_data;
 struct cpumask;
 
@@ -203,6 +205,9 @@ struct x86_io_apic_ops {
 	int		(*set_affinity)(struct irq_data *data,
 					const struct cpumask *mask,
 					bool force);
+	int		(*setup_entry)(int irq, struct IO_APIC_route_entry *entry,
+				       unsigned int destination, int vector,
+				       struct io_apic_irq_attr *attr);
 };
 
 extern struct x86_init_ops x86_init;

arch/x86/kernel/apic/io_apic.c

@@ -1315,14 +1315,10 @@ static void ioapic_register_intr(unsigned int irq, struct irq_cfg *cfg,
 				      fasteoi ? "fasteoi" : "edge");
 }
 
-static int setup_ioapic_entry(int irq, struct IO_APIC_route_entry *entry,
+int native_setup_ioapic_entry(int irq, struct IO_APIC_route_entry *entry,
 			      unsigned int destination, int vector,
 			      struct io_apic_irq_attr *attr)
 {
-	if (irq_remapping_enabled)
-		return setup_ioapic_remapped_entry(irq, entry, destination,
-						   vector, attr);
-
 	memset(entry, 0, sizeof(*entry));
 
 	entry->delivery_mode = apic->irq_delivery_mode;
@@ -1370,7 +1366,7 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg,
 		    attr->ioapic, mpc_ioapic_id(attr->ioapic), attr->ioapic_pin,
 		    cfg->vector, irq, attr->trigger, attr->polarity, dest);
 
-	if (setup_ioapic_entry(irq, &entry, dest, cfg->vector, attr)) {
+	if (x86_io_apic_ops.setup_entry(irq, &entry, dest, cfg->vector, attr)) {
 		pr_warn("Failed to setup ioapic entry for ioapic  %d, pin %d\n",
 			mpc_ioapic_id(attr->ioapic), attr->ioapic_pin);
 		__clear_irq_vector(irq, cfg);

arch/x86/kernel/x86_init.c

@@ -127,4 +127,5 @@ struct x86_io_apic_ops x86_io_apic_ops = {
 	.disable		= native_disable_io_apic,
 	.print_entries		= native_io_apic_print_entries,
 	.set_affinity		= native_ioapic_set_affinity,
+	.setup_entry		= native_setup_ioapic_entry,
 };

drivers/iommu/irq_remapping.c

@@ -146,6 +146,7 @@ static void __init irq_remapping_modify_x86_ops(void)
 {
 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
+	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
 }