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diff --git a/i386/i386at/gpl/linux/linux_autoirq.c b/i386/i386at/gpl/linux/linux_autoirq.c
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+/*
+ * Linux auto-irq support.
+ * 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.
+ */
+
+/*
+ *  Written 1994 by Donald Becker.
+ *
+ *  The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
+ *  Center of Excellence in Space Data and Information Sciences
+ *    Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
+ *
+ *  This code is a general-purpose IRQ line detector for devices with
+ *  jumpered IRQ lines.  If you can make the device raise an IRQ (and
+ *  that IRQ line isn't already being used), these routines will tell
+ *  you what IRQ line it's using -- perfect for those oh-so-cool boot-time
+ *  device probes!
+ *
+ *  To use this, first call autoirq_setup(timeout). TIMEOUT is how many
+ *  'jiffies' (1/100 sec.) to detect other devices that have active IRQ lines,
+ *  and can usually be zero at boot.  'autoirq_setup()' returns the bit
+ *  vector of nominally-available IRQ lines (lines may be physically in-use,
+ *  but not yet registered to a device).
+ *  Next, set up your device to trigger an interrupt.
+ *  Finally call autoirq_report(TIMEOUT) to find out which IRQ line was
+ *  most recently active.  The TIMEOUT should usually be zero, but may
+ *  be set to the number of jiffies to wait for a slow device to raise an IRQ.
+ *
+ *  The idea of using the setup timeout to filter out bogus IRQs came from
+ *  the serial driver.
+ */
+
+#include <i386/pic.h>
+#include <i386/ipl.h>
+
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+
+#include <asm/bitops.h>
+#include <asm/system.h>
+
+/*
+ * IRQ to network device map.
+ */
+void *irq2dev_map[16];
+
+/*
+ * Set of fixed IRQs
+ * (fpu, rtc, com1, PIC slave cascade, keyboard, timer).
+ */
+int irqs_busy = 0x2147;
+
+static volatile int irq_number;	/* latest irq found */
+static volatile int irq_bitmap;	/* bitmap of IRQs found */
+static int irq_handled;		/* irq lines we have a handler on */
+
+extern unsigned long loops_per_sec;
+
+/*
+ * Interrupt handler when probing an IRQ.
+ */
+static void
+autoirq_probe(irq)
+	int irq;
+{
+	/*
+	 * Mark this IRQ as the last one
+	 * that interrupted and disable it.
+	 */
+	irq_number = irq;
+	set_bit(irq, (void *)&irq_bitmap);
+	disable_irq(irq);
+}
+
+/*
+ * Set up for auto-irq.
+ */
+int
+autoirq_setup(waittime)
+	int waittime;
+{
+	int i, mask;
+	int timeout = jiffies + waittime;
+	int boguscount = (waittime * loops_per_sec) / 100;
+
+	/*
+	 * Allocate all possible IRQs.
+	 */
+	irq_handled = 0;
+	for (i = 0; i < 16; i++) {
+		if (test_bit(i, (void *)&irqs_busy) == 0
+		    && request_irq(i, autoirq_probe, 0, 0) == 0)
+			set_bit(i, (void *)&irq_handled);
+	}
+
+	irq_number = 0;
+	irq_bitmap = 0;
+
+	/*
+	 * Hang out at least <waittime>
+	 * jiffies waiting for bogus IRQ hits.
+	 */
+	while (timeout > jiffies && --boguscount > 0)
+		;
+
+	/*
+	 * Free IRQs that caused bogus hits.
+	 */
+	for (i = 0, mask = 0x01; i < 16; i++, mask <<= 1) {
+		if (irq_bitmap & irq_handled & mask) {
+			irq_handled &= ~mask;
+			free_irq(i);
+		}
+	}
+
+	return (irq_handled);
+}
+
+/*
+ * Return the last IRQ that caused an interrupt.
+ */
+int
+autoirq_report(waittime)
+	int waittime;
+{
+	int i;
+	int timeout = jiffies + waittime;
+	int boguscount = (waittime * loops_per_sec) / 100;
+
+	/*
+	 * Hang out at least <waittime>
+	 * jiffies waiting for the IRQ.
+	 */
+	while (timeout > jiffies && --boguscount > 0)
+		if (irq_number)
+			break;
+
+	/*
+	 * Retract the IRQ handlers that we handled.
+	 */
+	for (i = 0; i < 16; i++) {
+		if (test_bit(i, (void *)&irq_handled))
+			free_irq(i);
+	}
+
+	return (irq_number);
+}