linux/drivers/clocksource
Christoffer Dall e6d68b00e9 arm64: Use physical counter for in-kernel reads when booted in EL2
Using the physical counter allows KVM to retain the offset between the
virtual and physical counter as long as it is actively running a VCPU.

As soon as a VCPU is released, another thread is scheduled or we start
running userspace applications, we reset the offset to 0, so that
userspace accessing the virtual timer can still read the virtual counter
and get the same view of time as the kernel.

This opens up potential improvements for KVM performance, but we have to
make a few adjustments to preserve system consistency.

Currently get_cycles() is hardwired to arch_counter_get_cntvct() on
arm64, but as we move to using the physical timer for the in-kernel
time-keeping on systems that boot in EL2, we should use the same counter
for get_cycles() as for other in-kernel timekeeping operations.

Similarly, implementations of arch_timer_set_next_event_phys() is
modified to use the counter specific to the timer being programmed.

VHE kernels or kernels continuing to use the virtual timer are
unaffected.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06 16:23:09 +01:00
..
acpi_pm.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
arc_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
arm_arch_timer.c arm64: Use physical counter for in-kernel reads when booted in EL2 2017-11-06 16:23:09 +01:00
arm_global_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
armv7m_systick.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
asm9260_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
bcm2835_timer.c clocksource/drivers/bcm2835: Remove message for a memory allocation failure 2017-08-29 15:23:31 +02:00
bcm_kona_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
cadence_ttc_timer.c Merge branch 'timers/urgent' into timers/core 2017-06-21 09:07:52 +02:00
clksrc-dbx500-prcmu.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
clksrc_st_lpc.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
clps711x-timer.c clocksource/drivers: Rename CLKSRC_OF to TIMER_OF 2017-06-14 12:01:03 +02:00
cs5535-clockevt.c Annotate hardware config module parameters in drivers/clocksource/ 2017-04-20 12:02:32 +01:00
dummy_timer.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
dw_apb_timer.c Merge branch 'clockevents/4.12' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core 2017-04-17 10:55:14 +02:00
dw_apb_timer_of.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
em_sti.c clocksource/drivers/em_sti: Fix error return codes in em_sti_probe() 2017-08-10 14:48:18 +02:00
exynos_mct.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
fsl_ftm_timer.c clocksource/drivers/fsl_ftm_timer: Unmap region obtained by of_iomap 2017-06-27 11:25:39 +02:00
h8300_timer8.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
h8300_timer16.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
h8300_tpu.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
i8253.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
jcore-pit.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
Kconfig Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-04 13:06:34 -07:00
Makefile clocksource/drivers/imx-tpm: Add imx tpm timer support 2017-08-29 11:07:56 +02:00
meson6_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
metag_generic.c clockevents/drivers/metag: Set ->min_delta_ticks and ->max_delta_ticks 2017-04-14 13:11:13 -07:00
mips-gic-timer.c clocksource: mips-gic-timer: Use new GIC accessor functions 2017-08-30 14:30:07 +02:00
mmio.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
mps2-timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
mtk_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
mxs_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
nomadik-mtu.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
numachip.c x86/numachip: Add const and __initconst to numachip2_clockevent 2017-09-25 09:36:15 +02:00
owl-timer.c clocksource: owl: Add S900 support 2017-06-18 21:20:06 +02:00
pxa_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
qcom-timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
renesas-ostm.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
rockchip_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
samsung_pwm_timer.c clocksource/drivers: Rename CLKSRC_OF to TIMER_OF 2017-06-14 12:01:03 +02:00
scx200_hrt.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
sh_cmt.c clockevents/drivers/sh_cmt: Set ->min_delta_ticks and ->max_delta_ticks 2017-04-14 13:11:15 -07:00
sh_mtu2.c clocksource/drivers/sh_mtu2: Fix multiple shutdown call issue 2015-10-28 15:22:56 +01:00
sh_tmu.c clocksource: sh_tmu: Compute rate before registration again 2017-03-23 12:14:01 -07:00
sun4i_timer.c clocksource/drivers/sun4i: Switch to the timer-of common init 2017-06-26 18:32:04 +02:00
tango_xtal.c clocksource: Convert to using %pOF instead of full_name 2017-08-31 15:56:17 +02:00
tcb_clksrc.c clocksource/drivers/tcb_clksrc: Make IO endian agnostic 2017-06-27 11:25:20 +02:00
tegra20_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
time-armada-370-xp.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
time-efm32.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
time-lpc32xx.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
time-orion.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
time-pistachio.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-atlas7.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-atmel-pit.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-atmel-st.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-digicolor.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-fttmr010.c clocksource/drivers/fttmr010: Factor out clock read code 2017-06-14 12:02:50 +02:00
timer-imx-gpt.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-imx-tpm.c clocksource/drivers/imx-tpm: Add imx tpm timer support 2017-08-29 11:07:56 +02:00
timer-integrator-ap.c clocksource/integrator: Fix section mismatch warning 2017-09-18 09:37:33 +02:00
timer-keystone.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-nps.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-of.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-04 13:06:34 -07:00
timer-of.h clocksource/drivers: Add timer-of common init routine 2017-06-14 12:02:32 +02:00
timer-oxnas-rps.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-prima2.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-probe.c clocksource: Convert to using %pOF instead of full_name 2017-08-31 15:56:17 +02:00
timer-sp.h ARM: 8366/1: move Dual-Timer SP804 driver to drivers/clocksource 2015-06-02 09:58:18 +01:00
timer-sp804.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-stm32.c clocksource: Convert to using %pOF instead of full_name 2017-08-31 15:56:17 +02:00
timer-sun5i.c Merge branch 'timers/urgent' into timers/core 2017-06-21 09:07:52 +02:00
timer-ti-32k.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-u300.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
versatile.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
vf_pit_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
vt8500_timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
zevio-timer.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00