x86, io_apic: Introduce set_affinity function pointer

With interrupt remapping a special function is used to
change the affinity of an IO-APIC interrupt. Abstract this
with a function pointer.

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>
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 21aa81e..a744cbb 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -182,6 +182,9 @@
 extern void native_disable_io_apic(void);
 extern void native_io_apic_print_entries(unsigned int apic, unsigned int nr_entries);
 extern void intel_ir_io_apic_print_entries(unsigned int apic, unsigned int nr_entries);
+extern int native_ioapic_set_affinity(struct irq_data *,
+				      const struct cpumask *,
+				      bool);
 
 static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
 {
@@ -228,6 +231,7 @@
 #define native_io_apic_modify		NULL
 #define native_disable_io_apic		NULL
 #define native_io_apic_print_entries	NULL
+#define native_ioapic_set_affinity	NULL
 #endif
 
 #endif /* _ASM_X86_IO_APIC_H */