i8259: fix final ugliness

Introduce IRQx_VECTOR on 32-bit, so that #ifdef noise is kept
down. There should be no object code change.

[ mingo@elte.hu: merged to x86/irq not x86/i8259 due to x86/irq having
  restructured the vector code into asm-x86/irq_vectors.h, which this
  patch touches. ]

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/i8259.c

@@ -297,34 +297,28 @@ void init_8259A(int auto_eoi)
 	 * outb_pic - this has to work on a wide range of PC hardware.
 	 */
 	outb_pic(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */
-#ifndef CONFIG_X86_64
-	outb_pic(0x20 + 0, PIC_MASTER_IMR);	/* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
-	outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);	/* 8259A-1 (the master) has a slave on IR2 */
-#else /* CONFIG_X86_64 */
-	/* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
+
+	/* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
+	                       to 0x20-0x27 on i386 */
 	outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
+
 	/* 8259A-1 (the master) has a slave on IR2 */
-	outb_pic(0x04, PIC_MASTER_IMR);
-#endif /* CONFIG_X86_64 */
+	outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);
+
 	if (auto_eoi)	/* master does Auto EOI */
 		outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
 	else		/* master expects normal EOI */
 		outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
 
 	outb_pic(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */
-#ifndef CONFIG_X86_64
-	outb_pic(0x20 + 8, PIC_SLAVE_IMR);	/* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
-	outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR);	/* 8259A-2 is a slave on master's IR2 */
-	outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
-#else /* CONFIG_X86_64 */
-	/* ICW2: 8259A-2 IR0-7 mapped to 0x38-0x3f */
+
+	/* ICW2: 8259A-2 IR0-7 mapped to IRQ8_VECTOR */
 	outb_pic(IRQ8_VECTOR, PIC_SLAVE_IMR);
 	/* 8259A-2 is a slave on master's IR2 */
 	outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR);
 	/* (slave's support for AEOI in flat mode is to be investigated) */
 	outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR);
 
-#endif /* CONFIG_X86_64 */
 	if (auto_eoi)
 		/*
 		 * In AEOI mode we just have to mask the interrupt

include/asm-x86/irq_vectors.h

@@ -18,17 +18,20 @@
 #endif
 
 /*
- * Vectors 0x20-0x2f are used for ISA interrupts on 32 bit.
- *
  * Reserve the lowest usable priority level 0x20 - 0x2f for triggering
  * cleanup after irq migration on 64 bit.
  */
 #define IRQ_MOVE_CLEANUP_VECTOR	FIRST_EXTERNAL_VECTOR
 
 /*
- * Vectors 0x30-0x3f are used for ISA interrupts on 64 bit
+ * Vectors 0x20-0x2f are used for ISA interrupts on 32 bit.
+ * Vectors 0x30-0x3f are used for ISA interrupts on 64 bit.
  */
+#ifdef CONFIG_X86_32
+#define IRQ0_VECTOR		(FIRST_EXTERNAL_VECTOR)
+#else
 #define IRQ0_VECTOR		(FIRST_EXTERNAL_VECTOR + 0x10)
+#endif
 #define IRQ1_VECTOR		(IRQ0_VECTOR + 1)
 #define IRQ2_VECTOR		(IRQ0_VECTOR + 2)
 #define IRQ3_VECTOR		(IRQ0_VECTOR + 3)