x86/hpet: Do not use smp_processor_id() in preemptible code

When hpet=force is supplied on the kernel command line and the HPET
supports the Legacy Replacement Interrupt Route option (HPET_ID_LEGSUP),
the legacy interrupts init code uses the boot CPU's mask initially by
calling smp_processor_id() assuming that it is running on the BSP.

It does run on the BSP but the code region is preemptible and the
preemption check fires.

Simply use the BSP's id directly to avoid the warning.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170620093154.18472-1-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 89ff7af2de508ba0c34c2ce24c227dea5bf6d973..16f82a3aaec7c9c8d85e7c8b4f805da396981fce 100644 (file)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -285,7 +285,7 @@ static void hpet_legacy_clockevent_register(void)
         * Start hpet with the boot cpu mask and make it
         * global after the IO_APIC has been initialized.
         */
-       hpet_clockevent.cpumask = cpumask_of(smp_processor_id());
+       hpet_clockevent.cpumask = cpumask_of(boot_cpu_data.cpu_index);
        clockevents_config_and_register(&hpet_clockevent, hpet_freq,
                                        HPET_MIN_PROG_DELTA, 0x7FFFFFFF);
        global_clock_event = &hpet_clockevent;