add directory net

net/tcpip/newether-pingpong/auto_irq.c

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+/* auto_irq.c: Auto-configure IRQ lines for linux. */
+/*
+    Written 1993 by Donald Becker. This is alpha test code.
+
+    The Author may be reached as becker@super.org or
+    C/O Supercomputing Research Ctr., 17100 Science Dr., Bowie MD 20715
+
+    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' (1/18 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.
+*/
+
+
+#ifdef version
+static char *version="auto_irq.c:v0.01 1993 Donald Becker (becker@super.org)";
+#endif
+
+/*#include <linux/config.h>*/
+/*#include <linux/kernel.h>*/
+#include <linux/sched.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+/*#include <asm/system.h>*/
+
+int irqs_busy = 0x01;		/* The set of fixed IRQs always enabled */
+int irqs_used = 0x01;		/* The set of fixed IRQs sometimes enabled. */
+int irqs_reserved = 0x00;	/* An advisory "reserved" table. */
+int irqs_shared = 0x00;		/* IRQ lines "shared" among conforming cards.*/
+
+static volatile int irq_number;	/* The latest irq number we actually found. */
+static volatile int irq_bitmap; /* The irqs we actually found. */
+static int irq_handled;		/* The irq lines we have a handler on. */
+
+static void autoirq_probe(int irq)
+{
+	irq_number = irq;
+	set_bit(irq, (void *)&irq_bitmap);	/* irq_bitmap |= 1 << irq; */
+	return;
+}
+struct sigaction autoirq_sigaction = { autoirq_probe, 0, SA_INTERRUPT, NULL};
+
+int autoirq_setup(int waittime)
+{
+    int i, mask;
+    int timeout = jiffies+waittime;
+
+    irq_number = 0;
+    irq_bitmap = 0;
+    irq_handled = 0;
+    for (i = 0; i < 16; i++) {
+	if (!irqaction(i, &autoirq_sigaction))
+	    set_bit(i, (void *)&irq_handled);	/* irq_handled |= 1 << i;*/
+    }
+    /* Update our USED lists. */
+    irqs_used |= ~irq_handled;
+
+    /* Hang out at least <waittime> jiffies waiting for bogus IRQ hits. */
+    while (timeout >= jiffies)
+	;
+
+    for (i = 0, mask = 0x01; i < 16; i++, mask <<= 1) {
+	if (irq_bitmap & irq_handled & mask) {
+	    irq_handled &= ~mask;
+	    printk(" Spurious interrupt on IRQ %d\n", i);
+	    free_irq(i);
+	}
+    }
+    return irq_handled;
+}
+
+int autoirq_report(int waittime)
+{
+    int i;
+    int timeout = jiffies+waittime;
+
+    /* Hang out at least <waittime> jiffies waiting for the IRQ. */
+    while (timeout >= jiffies)
+	if (irq_number)
+	    break;
+
+    /* Retract the irq handlers that we installed. */
+    for (i = 0; i < 16; i++) {
+	if (test_bit(i, (void *)&irq_handled))
+	    free_irq(i);
+    }
+    return irq_number;
+}
+
+/*
+ * Local variables:
+ *  compile-command: "gcc -DKERNEL -Wall -O6 -fomit-frame-pointer -I/usr/src/linux/net/tcp -c auto_irq.c"
+ *  version-control: t
+ *  kept-new-versions: 5
+ * End:
+ */