1 files changed, 103 insertions, 0 deletions
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
new file mode 100644
index 000000000..0680a2e9e
--- /dev/null
+++ b/arch/x86/kernel/time.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (c) 1991,1992,1995  Linus Torvalds
+ *  Copyright (c) 1994  Alan Modra
+ *  Copyright (c) 1995  Markus Kuhn
+ *  Copyright (c) 1996  Ingo Molnar
+ *  Copyright (c) 1998  Andrea Arcangeli
+ *  Copyright (c) 2002,2006  Vojtech Pavlik
+ *  Copyright (c) 2003  Andi Kleen
+ *
+ */
+
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/i8253.h>
+#include <linux/time.h>
+#include <linux/export.h>
+
+#include <asm/vsyscall.h>
+#include <asm/x86_init.h>
+#include <asm/i8259.h>
+#include <asm/timer.h>
+#include <asm/hpet.h>
+#include <asm/time.h>
+
+unsigned long profile_pc(struct pt_regs *regs)
+{
+	unsigned long pc = instruction_pointer(regs);
+
+	if (!user_mode(regs) && in_lock_functions(pc)) {
+#ifdef CONFIG_FRAME_POINTER
+		return *(unsigned long *)(regs->bp + sizeof(long));
+#else
+		unsigned long *sp =
+			(unsigned long *)kernel_stack_pointer(regs);
+		/*
+		 * Return address is either directly at stack pointer
+		 * or above a saved flags. Eflags has bits 22-31 zero,
+		 * kernel addresses don't.
+		 */
+		if (sp[0] >> 22)
+			return sp[0];
+		if (sp[1] >> 22)
+			return sp[1];
+#endif
+	}
+	return pc;
+}
+EXPORT_SYMBOL(profile_pc);
+
+/*
+ * Default timer interrupt handler for PIT/HPET
+ */
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	global_clock_event->event_handler(global_clock_event);
+	return IRQ_HANDLED;
+}
+
+static struct irqaction irq0  = {
+	.handler = timer_interrupt,
+	.flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
+	.name = "timer"
+};
+
+static void __init setup_default_timer_irq(void)
+{
+	/*
+	 * Unconditionally register the legacy timer; even without legacy
+	 * PIC/PIT we need this for the HPET0 in legacy replacement mode.
+	 */
+	if (setup_irq(0, &irq0))
+		pr_info("Failed to register legacy timer interrupt\n");
+}
+
+/* Default timer init function */
+void __init hpet_time_init(void)
+{
+	if (!hpet_enable())
+		setup_pit_timer();
+	setup_default_timer_irq();
+}
+
+static __init void x86_late_time_init(void)
+{
+	x86_init.timers.timer_init();
+	/*
+	 * After PIT/HPET timers init, select and setup
+	 * the final interrupt mode for delivering IRQs.
+	 */
+	x86_init.irqs.intr_mode_init();
+	tsc_init();
+}
+
+/*
+ * Initialize TSC and delay the periodic timer init to
+ * late x86_late_time_init() so ioremap works.
+ */
+void __init time_init(void)
+{
+	late_time_init = x86_late_time_init;
+}