1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/linkage.h>
3 #include <linux/errno.h>
4 #include <linux/signal.h>
5 #include <linux/sched.h>
6 #include <linux/ioport.h>
7 #include <linux/interrupt.h>
8 #include <linux/irq.h>
9 #include <linux/timex.h>
10 #include <linux/random.h>
11 #include <linux/init.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/syscore_ops.h>
14 #include <linux/bitops.h>
15 #include <linux/acpi.h>
16 #include <linux/io.h>
17 #include <linux/delay.h>
18 #include <linux/pgtable.h>
20 #include <linux/atomic.h>
21 #include <asm/timer.h>
22 #include <asm/hw_irq.h>
23 #include <asm/desc.h>
24 #include <asm/apic.h>
25 #include <asm/i8259.h>
28  * This is the 'legacy' 8259A Programmable Interrupt Controller,
40  * 8259A PIC functions to handle ISA devices:
44  * This contains the irq mask for both 8259A irq controllers,
49  * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
50  * boards the timer interrupt is not really connected to any IO-APIC pin,
51  * it's fed to the master 8259A's IR0 line only.
53  * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
75 	mask_8259A_irq(data->irq);  in disable_8259A_irq()
94 	unmask_8259A_irq(data->irq);  in enable_8259A_irq()
125  * 8259A registers is slow.
147  * Careful! The 8259A is a fragile beast, it pretty
154 	unsigned int irq = data->irq;  in mask_and_ack_8259A()
161 	 * to overdo spurious IRQ handling - it's usually a sign  in mask_and_ack_8259A()
166 	 * usually resulting from the 8259A-1|2 PICs) occur  in mask_and_ack_8259A()
167 	 * even if the IRQ is masked in the 8259A. Thus we  in mask_and_ack_8259A()
168 	 * can check spurious 8259A IRQs without doing the  in mask_and_ack_8259A()
180 		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */  in mask_and_ack_8259A()
184 		 /* 'Specific EOI' to master-IRQ2 */  in mask_and_ack_8259A()
187 		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */  in mask_and_ack_8259A()
196 	 * this is the slow path - should happen rarely.  in mask_and_ack_8259A()
201 		 * 8259A - not spurious, go handle it.  in mask_and_ack_8259A()
213 			       "spurious 8259A interrupt: IRQ%d.\n", irq);  in mask_and_ack_8259A()
227 	.name		= "XT-PIC",
263 	/* Put the i8259A into a quiescent state that  in i8259A_shutdown()
267 	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */  in i8259A_shutdown()
268 	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */  in i8259A_shutdown()
283 	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */  in mask_8259A()
284 	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */  in mask_8259A()
316 	 * there and let legacy_pic->init() initialize it for nothing.  in probe_8259A()
326 	 * Check to see if we have a PIC.  Mask all except the cascade and  in probe_8259A()
327 	 * read back the value we just wrote. If we don't have a PIC, we  in probe_8259A()
332 	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */  in probe_8259A()
352 	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */  in init_8259A()
355 	 * outb_pic - this has to work on a wide range of PC hardware.  in init_8259A()
357 	outb_pic(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */  in init_8259A()
359 	/* ICW2: 8259A-1 IR0-7 mapped to ISA_IRQ_VECTOR(0) */  in init_8259A()
362 	/* 8259A-1 (the master) has a slave on IR2 */  in init_8259A()
370 	outb_pic(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */  in init_8259A()
372 	/* ICW2: 8259A-2 IR0-7 mapped to ISA_IRQ_VECTOR(8) */  in init_8259A()
374 	/* 8259A-2 is a slave on master's IR2 */  in init_8259A()
388 	udelay(100);		/* wait for 8259A to initialize */  in init_8259A()
397  * make i8259 a driver so that we can select pic functions at run time. the goal
398  * is to make x86 binary compatible among pc compatible and non-pc compatible