+void init_8259A(int auto_eoi)
+{
+ unsigned long flags;
+
+ i8259A_auto_eoi = auto_eoi;
+
+ spin_lock_irqsave(&i8259A_lock, flags);
+
+ outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
+ outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
+
+ /*
+ * outb_pic - this has to work on a wide range of PC hardware.
+ */
+ outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
+ /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
+ outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
+ /* 8259A-1 (the master) has a slave on IR2 */
+ outb_pic(0x04, 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 */
+ /* ICW2: 8259A-2 IR0-7 mapped to 0x38-0x3f */
+ 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);
+
+ if (auto_eoi)
+ /*
+ * In AEOI mode we just have to mask the interrupt
+ * when acking.
+ */
+ i8259A_chip.mask_ack = disable_8259A_irq;
+ else
+ i8259A_chip.mask_ack = mask_and_ack_8259A;
+
+ udelay(100); /* wait for 8259A to initialize */
+
+ outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
+ outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
+
+ spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+
+
+