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!
diff --git a/include/asm-mips/i8259.h b/include/asm-mips/i8259.h
new file mode 100644
index 0000000..0214abe
--- /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 <ralf@linux-mips.org>
+ *
+ * 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 <linux/compiler.h>
+#include <linux/spinlock.h>
+
+#include <asm/io.h>
+
+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 */
