v4.19.13 snapshot.
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
new file mode 100644
index 0000000..fddaefc
--- /dev/null
+++ b/arch/x86/kernel/time.c
@@ -0,0 +1,107 @@
+// 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>
+
+#ifdef CONFIG_X86_64
+__visible volatile unsigned long jiffies __cacheline_aligned_in_smp = INITIAL_JIFFIES;
+#endif
+
+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;
+}