1 // SPDX-License-Identifier: GPL-2.0-or-later
15 static volatile void __iomem *pci_intack; /* RO, gives us the irq vector */
26  * Acknowledge the IRQ using either the PCI host bridge's interrupt
29  * IBM and Motorola PReP boxes so we must use the int-ack feature on them.
33 	int irq;  in i8259_irq()  local
36 	/* Either int-ack or poll for the IRQ */  in i8259_irq()
38 		irq = readb(pci_intack);  in i8259_irq()
45 		irq = inb(0x20) & 7;  in i8259_irq()
46 		if (irq == 2 ) {  in i8259_irq()
52 			irq = (inb(0xA0) & 7) + 8;  in i8259_irq()
56 	if (irq == 7) {  in i8259_irq()
67 			irq = 0;  in i8259_irq()
68 	} else if (irq == 0xff)  in i8259_irq()
69 		irq = 0;  in i8259_irq()
73 	return irq;  in i8259_irq()
81 	if (d->irq > 7) {  in i8259_mask_and_ack_irq()
82 		cached_A1 |= 1 << (d->irq-8);  in i8259_mask_and_ack_irq()
85 		outb(0x20, 0xA0);	/* Non-specific EOI */  in i8259_mask_and_ack_irq()
86 		outb(0x20, 0x20);	/* Non-specific EOI to cascade */  in i8259_mask_and_ack_irq()
88 		cached_21 |= 1 << d->irq;  in i8259_mask_and_ack_irq()
91 		outb(0x20, 0x20);	/* Non-specific EOI */  in i8259_mask_and_ack_irq()
106 	pr_debug("i8259_mask_irq(%d)\n", d->irq);  in i8259_mask_irq()
109 	if (d->irq < 8)  in i8259_mask_irq()
110 		cached_21 |= 1 << d->irq;  in i8259_mask_irq()
112 		cached_A1 |= 1 << (d->irq-8);  in i8259_mask_irq()
113 	i8259_set_irq_mask(d->irq);  in i8259_mask_irq()
121 	pr_debug("i8259_unmask_irq(%d)\n", d->irq);  in i8259_unmask_irq()
124 	if (d->irq < 8)  in i8259_unmask_irq()
125 		cached_21 &= ~(1 << d->irq);  in i8259_unmask_irq()
127 		cached_A1 &= ~(1 << (d->irq-8));  in i8259_unmask_irq()
128 	i8259_set_irq_mask(d->irq);  in i8259_unmask_irq()
142 	.start = 0x20,
149 	.start = 0xa0,
156 	.start = 0x4d0,
217  * i8259_init - Initialize the legacy controller
221  *             	 the active irq from the 8259
235 	outb(0x11, 0x20); /* Start init sequence */  in i8259_init()
241 	outb(0x11, 0xA0); /* Start init sequence */  in i8259_init()
266 		printk(KERN_ERR "i8259: failed to allocate irq host !\n");  in i8259_init()