drivers/irqchip/irq-i8259.c

6  * Code to handle x86 style IRQs plus some generic interrupt stuff.
9  * Copyright (C) 1994 - 2000 Ralf Baechle
35 static int i8259A_auto_eoi = -1;
44 	.name			= "XT-PIC",
70 	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;  in disable_8259A_irq()
85 	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;  in enable_8259A_irq()
136 	unsigned int irqmask, irq = d->irq - I8259A_IRQ_BASE;  in mask_and_ack_8259A()
143 	 * to overdo spurious IRQ handling - it's usually a sign  in mask_and_ack_8259A()
147 	 * Note that IRQ7 and IRQ15 (the two spurious IRQs  in mask_and_ack_8259A()
148 	 * usually resulting from the 8259A-1|2 PICs) occur  in mask_and_ack_8259A()
150 	 * can check spurious 8259A IRQs without doing the  in mask_and_ack_8259A()
162 		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */  in mask_and_ack_8259A()
165 		outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */  in mask_and_ack_8259A()
167 		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */  in mask_and_ack_8259A()
176 	 * this is the slow path - should happen rarely.  in mask_and_ack_8259A()
181 		 * 8259A - not spurious, go handle it.  in mask_and_ack_8259A()
218 		outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */  in i8259A_shutdown()
219 		outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */  in i8259A_shutdown()
236 	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */  in init_8259A()
237 	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */  in init_8259A()
240 	 * outb_p - this has to work on a wide range of PC hardware.  in init_8259A()
242 	outb_p(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */  in init_8259A()
243 …outb_p(I8259A_IRQ_BASE + 0, PIC_MASTER_IMR);	/* ICW2: 8259A-1 IR0 mapped to I8259A_IRQ_BASE + 0x00…  in init_8259A()
244 	outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);	/* 8259A-1 (the master) has a slave on IR2 */  in init_8259A()
250 	outb_p(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */  in init_8259A()
251 …outb_p(I8259A_IRQ_BASE + 8, PIC_SLAVE_IMR);	/* ICW2: 8259A-2 IR0 mapped to I8259A_IRQ_BASE + 0x08 …  in init_8259A()
252 	outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR);	/* 8259A-2 is a slave on master's IR2 */  in init_8259A()
294 	.map = i8259A_irq_domain_map,
299  * On systems with i8259-style interrupt controllers we assume for
300  * driver compatibility reasons interrupts 0 - 15 to be the i8259
352 		pr_err("Failed to map i8259 parent IRQ\n");  in i8259_of_init()
354 		return -ENODEV;  in i8259_of_init()