1 files changed, 114 insertions, 0 deletions

diff --git a/arch/x86/kernel/irqinit_32.c b/arch/x86/kernel/irqinit_32.c
new file mode 100644
index 000000000000..d66914287ee1
--- /dev/null
+++ b/arch/x86/kernel/irqinit_32.c
@@ -0,0 +1,114 @@
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/sysdev.h>
+#include <linux/bitops.h>
+
+#include <asm/atomic.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/timer.h>
+#include <asm/pgtable.h>
+#include <asm/delay.h>
+#include <asm/desc.h>
+#include <asm/apic.h>
+#include <asm/arch_hooks.h>
+#include <asm/i8259.h>
+
+
+
+/*
+ * Note that on a 486, we don't want to do a SIGFPE on an irq13
+ * as the irq is unreliable, and exception 16 works correctly
+ * (ie as explained in the intel literature). On a 386, you
+ * can't use exception 16 due to bad IBM design, so we have to
+ * rely on the less exact irq13.
+ *
+ * Careful.. Not only is IRQ13 unreliable, but it is also
+ * leads to races. IBM designers who came up with it should
+ * be shot.
+ */
+ 
+
+static irqreturn_t math_error_irq(int cpl, void *dev_id)
+{
+        extern void math_error(void __user *);
+        outb(0,0xF0);
+        if (ignore_fpu_irq || !boot_cpu_data.hard_math)
+                return IRQ_NONE;
+        math_error((void __user *)get_irq_regs()->ip);
+        return IRQ_HANDLED;
+}
+
+/*
+ * New motherboards sometimes make IRQ 13 be a PCI interrupt,
+ * so allow interrupt sharing.
+ */
+static struct irqaction fpu_irq = {
+        .handler = math_error_irq,
+        .mask = CPU_MASK_NONE,
+        .name = "fpu",
+};
+
+void __init init_ISA_irqs (void)
+{
+        int i;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+        init_bsp_APIC();
+#endif
+        init_8259A(0);
+
+        /*
+         * 16 old-style INTA-cycle interrupts:
+         */
+        for (i = 0; i < 16; i++) {
+                set_irq_chip_and_handler_name(i, &i8259A_chip,
+                                              handle_level_irq, "XT");
+        }
+}
+
+/* Overridden in paravirt.c */
+void init_IRQ(void) __attribute__((weak, alias("native_init_IRQ")));
+
+void __init native_init_IRQ(void)
+{
+        int i;
+
+        /* all the set up before the call gates are initialised */
+        pre_intr_init_hook();
+
+        /*
+         * Cover the whole vector space, no vector can escape
+         * us. (some of these will be overridden and become
+         * 'special' SMP interrupts)
+         */
+        for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
+                int vector = FIRST_EXTERNAL_VECTOR + i;
+                if (i >= NR_IRQS)
+                        break;
+                /* SYSCALL_VECTOR was reserved in trap_init. */
+                if (!test_bit(vector, used_vectors))
+                        set_intr_gate(vector, interrupt[i]);
+        }
+
+        /* setup after call gates are initialised (usually add in
+         * the architecture specific gates)
+         */
+        intr_init_hook();
+
+        /*
+         * External FPU? Set up irq13 if so, for
+         * original braindamaged IBM FERR coupling.
+         */
+        if (boot_cpu_data.hard_math && !cpu_has_fpu)
+                setup_irq(FPU_IRQ, &fpu_irq);
+
+        irq_ctx_init(smp_processor_id());
+}