mirror_ubuntu-kernels/arch/x86/kernel/apic
Dou Liyang ca7c6076ba x86/ioapic: Refactor the delay logic in timer_irq_works()
timer_irq_works() is used to detects the timer IRQs. It calls mdelay(10) to
delay ten ticks and check whether the timer IRQ work or not.

mdelay() depends on the loops_per_jiffy which is set up in
calibrate_delay(), but the delay calibration depends on a working timer
interrupt, which causes a chicken and egg problem.

The correct solution is to set up the interrupt mode and making sure that
the timer interrupt is delivered correctly before invoking calibrate_delay().
That means that mdelay() cannot be used in timer_irq_works(). 

Provide helper functions to make a rough delay estimate which is good enough
to prove that the timer interrupt is working. Either use TSC or a simple
delay loop and assume that 4GHz is the maximum CPU frequency to base the
delay calculation on.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-9-git-send-email-douly.fnst@cn.fujitsu.com
2017-09-25 15:03:16 +02:00
..
apic_flat_64.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
apic_noop.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
apic_numachip.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
apic.c x86/apic: Unify interrupt mode setup for UP system 2017-09-25 15:03:16 +02:00
bigsmp_32.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
htirq.c x86/htirq: Create named domain 2017-06-22 18:21:09 +02:00
hw_nmi.c kernel/watchdog: split up config options 2017-07-12 16:26:02 -07:00
io_apic.c x86/ioapic: Refactor the delay logic in timer_irq_works() 2017-09-25 15:03:16 +02:00
ipi.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
Makefile kernel: add kcov code coverage 2016-03-22 15:36:02 -07:00
msi.c x86/msi: Create named irq domains 2017-06-22 18:21:11 +02:00
probe_32.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
probe_64.c x86/apic: Remove duplicated include from probe_64.c 2016-07-19 16:02:31 +02:00
vector.c x86/irq: Get rid of the 'first_system_vector' indirection bogosity 2017-08-29 11:42:21 +02:00
x2apic_cluster.c x86/apic: Implement effective irq mask update 2017-06-22 18:21:23 +02:00
x2apic_phys.c x86/apic: Move cpumask and to core code 2017-06-22 18:21:22 +02:00
x2apic_uv_x.c x86/apic: Add irq_data argument to apic->cpu_mask_to_apicid() 2017-06-22 18:21:22 +02:00