1 /*
2 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <gpxe/io.h>
22 #include <pic8259.h>
23
24 /** @file
25 *
26 * Minimal support for the 8259 Programmable Interrupt Controller
27 *
28 */
29
30 /**
31 * Send non-specific EOI(s)
32 *
33 * @v irq IRQ number
34 *
35 * This seems to be inherently unsafe.
36 */
send_nonspecific_eoi(unsigned int irq)37 static inline void send_nonspecific_eoi ( unsigned int irq ) {
38 DBG ( "Sending non-specific EOI for IRQ %d\n", irq );
39 if ( irq >= IRQ_PIC_CUTOFF ) {
40 outb ( ICR_EOI_NON_SPECIFIC, PIC2_ICR );
41 }
42 outb ( ICR_EOI_NON_SPECIFIC, PIC1_ICR );
43 }
44
45 /**
46 * Send specific EOI(s)
47 *
48 * @v irq IRQ number
49 */
send_specific_eoi(unsigned int irq)50 static inline void send_specific_eoi ( unsigned int irq ) {
51 DBG ( "Sending specific EOI for IRQ %d\n", irq );
52 if ( irq >= IRQ_PIC_CUTOFF ) {
53 outb ( ( ICR_EOI_SPECIFIC | ICR_VALUE ( CHAINED_IRQ ) ),
54 ICR_REG ( CHAINED_IRQ ) );
55 }
56 outb ( ( ICR_EOI_SPECIFIC | ICR_VALUE ( irq ) ), ICR_REG ( irq ) );
57 }
58
59 /**
60 * Send End-Of-Interrupt to the PIC
61 *
62 * @v irq IRQ number
63 */
send_eoi(unsigned int irq)64 void send_eoi ( unsigned int irq ) {
65 send_specific_eoi ( irq );
66 }
67