diff options
Diffstat (limited to 'i386/i386/pic.c')
| -rw-r--r-- | i386/i386/pic.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/i386/i386/pic.c b/i386/i386/pic.c index 0feebc6f..62ed9ed1 100644 --- a/i386/i386/pic.c +++ b/i386/i386/pic.c @@ -49,6 +49,24 @@ OTHER TORTIOUS ACTION, ARISING OUR OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ +/* + * Copyright (C) 1995 Shantanu Goel. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + #include <sys/types.h> #include <kern/printf.h> #include <i386/ipl.h> @@ -185,3 +203,57 @@ intnull(int unit_dev) } } + +/* + * Mask a PIC IRQ. + */ +inline void +mask_irq (unsigned int irq_nr) +{ + int new_pic_mask = curr_pic_mask | 1 << irq_nr; + + if (curr_pic_mask != new_pic_mask) + { + curr_pic_mask = new_pic_mask; + if (irq_nr < 8) + { + outb (PIC_MASTER_OCW, curr_pic_mask & 0xff); + } + else + { + outb (PIC_SLAVE_OCW, curr_pic_mask >> 8); + } + } +} + +/* + * Unmask a PIC IRQ. + */ +inline void +unmask_irq (unsigned int irq_nr) +{ + int mask; + int new_pic_mask; + + mask = 1 << irq_nr; + if (irq_nr >= 8) + { + mask |= 1 << 2; + } + + new_pic_mask = curr_pic_mask & ~mask; + + if (curr_pic_mask != new_pic_mask) + { + curr_pic_mask = new_pic_mask; + if (irq_nr < 8) + { + outb (PIC_MASTER_OCW, curr_pic_mask & 0xff); + } + else + { + outb (PIC_SLAVE_OCW, curr_pic_mask >> 8); + } + } +} + |