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Diffstat (limited to 'arch/x86/kernel/irqinit_32.c')
-rw-r--r--arch/x86/kernel/irqinit_32.c114
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 0000000..d669142
--- /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());
+}
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