x86: Add a function to set the IOAPIC ID

Add a function to set the ID in the IOAPIC.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/ioapic.c

@@ -7,6 +7,7 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/ioapic.h>
+#include <asm/lapic.h>
 
 u32 io_apic_read(u32 reg)
 {
@@ -19,3 +20,18 @@ void io_apic_write(u32 reg, u32 val)
 	writel(reg, IO_APIC_INDEX);
 	writel(val, IO_APIC_DATA);
 }
+
+void io_apic_set_id(int ioapic_id)
+{
+	int bsp_lapicid = lapicid();
+
+	debug("IOAPIC: Initialising IOAPIC at %08x\n", IO_APIC_ADDR);
+	debug("IOAPIC: Bootstrap Processor Local APIC = %#02x\n", bsp_lapicid);
+
+	if (ioapic_id) {
+		debug("IOAPIC: ID = 0x%02x\n", ioapic_id);
+		/* Set IOAPIC ID if it has been specified */
+		io_apic_write(0x00, (io_apic_read(0x00) & 0xf0ffffff) |
+			      (ioapic_id << 24));
+	}
+}

arch/x86/include/asm/ioapic.h

@@ -39,4 +39,6 @@ u32 io_apic_read(u32 reg);
  */
 void io_apic_write(u32 reg, u32 val);
 
+void io_apic_set_id(int ioapic_id);
+
 #endif