From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/asm-mips/i8259.h | 67 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 include/asm-mips/i8259.h (limited to 'include/asm-mips/i8259.h') diff --git a/include/asm-mips/i8259.h b/include/asm-mips/i8259.h new file mode 100644 index 00000000000..0214abe3f0a --- /dev/null +++ b/include/asm-mips/i8259.h @@ -0,0 +1,67 @@ +/* + * include/asm-mips/i8259.h + * + * i8259A interrupt definitions. + * + * Copyright (C) 2003 Maciej W. Rozycki + * Copyright (C) 2003 Ralf Baechle + * + * 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 of the License, or (at your option) any later version. + */ +#ifndef _ASM_I8259_H +#define _ASM_I8259_H + +#include +#include + +#include + +extern spinlock_t i8259A_lock; + +extern void init_i8259_irqs(void); + +/* + * Do the traditional i8259 interrupt polling thing. This is for the few + * cases where no better interrupt acknowledge method is available and we + * absolutely must touch the i8259. + */ +static inline int i8259_irq(void) +{ + int irq; + + spin_lock(&i8259A_lock); + + /* Perform an interrupt acknowledge cycle on controller 1. */ + outb(0x0C, 0x20); /* prepare for poll */ + irq = inb(0x20) & 7; + if (irq == 2) { + /* + * Interrupt is cascaded so perform interrupt + * acknowledge on controller 2. + */ + outb(0x0C, 0xA0); /* prepare for poll */ + irq = (inb(0xA0) & 7) + 8; + } + + if (unlikely(irq == 7)) { + /* + * This may be a spurious interrupt. + * + * Read the interrupt status register (ISR). If the most + * significant bit is not set then there is no valid + * interrupt. + */ + outb(0x0B, 0x20); /* ISR register */ + if(~inb(0x20) & 0x80) + irq = -1; + } + + spin_unlock(&i8259A_lock); + + return irq; +} + +#endif /* _ASM_I8259_H */ -- cgit v1.2.3