linux/drivers/clocksource
David Woodhouse caae544264 x86/i8253: Disable PIT timer 0 when not in use
commit 70e6b7d9ae upstream.

Leaving the PIT interrupt running can cause noticeable steal time for
virtual guests. The VMM generally has a timer which toggles the IRQ input
to the PIC and I/O APIC, which takes CPU time away from the guest. Even
on real hardware, running the counter may use power needlessly (albeit
not much).

Make sure it's turned off if it isn't going to be used.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhkelley@outlook.com>
Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-03-13 12:50:46 +01:00
..
acpi_pm.c clocksource: acpi_pm: fix return value of __setup handler 2022-04-08 14:23:09 +02:00
arc_timer.c clocksource/drivers/arc_timer: Remove duplicate error message 2020-05-22 23:58:56 +02:00
arm_arch_timer.c clocksource/arm_arch_timer: Improve Allwinner A64 timer workaround 2021-06-16 17:33:04 +02:00
arm_global_timer.c clocksource/drivers/arm_global_timer: Guard against division by zero 2024-09-04 13:23:25 +02:00
armv7m_systick.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
asm9260_timer.c clocksource/drivers/asm9260: Add a check for of_clk_get 2019-11-04 10:40:10 +01:00
bcm2835_timer.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
bcm_kona_timer.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
clksrc-dbx500-prcmu.c timekeeping, clocksource: Fix various typos in comments 2021-03-22 23:06:48 +01:00
clksrc_st_lpc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
clps711x-timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dummy_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dw_apb_timer.c clocksource: dw_apb_timer: Make CPU-affiliation being optional 2020-05-23 00:02:41 +02:00
dw_apb_timer_of.c clocksource/drivers/dw_apb_timer_of: Fix probe failure 2021-12-14 10:57:23 +01:00
em_sti.c clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe 2020-01-16 19:06:57 +01:00
exynos_mct.c clocksource/drivers/exynos_mct: Handle DTS with higher number of interrupts 2022-04-08 14:23:08 +02:00
h8300_timer8.c clocksource/drivers/h8300_timer8: Fix wrong return value in h8300_8timer_init() 2020-08-24 13:01:38 +02:00
h8300_timer16.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
h8300_tpu.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hyperv_timer.c x86/hyperv: Fix hv tsc page based sched_clock for hibernation 2025-01-09 13:28:42 +01:00
i8253.c x86/i8253: Disable PIT timer 0 when not in use 2025-03-13 12:50:46 +01:00
ingenic-ost.c clocksource/drivers/ingenic_ost: Fix return value check in ingenic_ost_probe() 2021-04-08 13:24:15 +02:00
ingenic-sysost.c clocksource/drivers/ingenic: Use bitfield macro helpers 2021-08-14 02:44:35 +02:00
ingenic-timer.c clocksource/drivers/ingenic: Add support for the JZ4760 2021-04-08 13:23:22 +02:00
jcore-pit.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
Kconfig clocksource/drivers:sp804: Make user selectable 2024-12-14 19:50:46 +01:00
Makefile clocksource/drivers/prima: Remove sirf prima driver 2021-02-03 09:13:46 +01:00
mips-gic-timer.c clocksource: mips-gic-timer: Mark GIC timer as unstable if ref clock changes 2020-05-23 00:03:16 +02:00
mmio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
mps2-timer.c clocksource/drivers/mps2-timer: Use semicolons rather than commas to separate statements 2020-10-01 10:07:26 +02:00
mxs_timer.c clocksource/drivers/mxs_timer: Add missing semicolon when DEBUG is defined 2021-01-18 22:28:59 +01:00
nomadik-mtu.c clocksource/drivers/nomadik-mtu: Handle 32kHz clock 2020-07-23 16:57:43 +02:00
numachip.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
renesas-ostm.c clocksource/drivers/renesas-ostm: Use unique device name instead of ostm 2019-11-04 10:38:46 +01:00
samsung_pwm_timer.c clocksource/drivers/samsung_pwm: Constify source IO memory 2021-06-04 10:12:13 +02:00
scx200_hrt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sh_cmt.c clocksource/drivers/sh_cmt: Address race condition for clock events 2024-08-19 05:45:37 +02:00
sh_mtu2.c PM: domains: Rename pm_genpd_syscore_poweroff|poweron() 2020-11-10 20:42:01 +01:00
sh_tmu.c PM: domains: Rename pm_genpd_syscore_poweroff|poweron() 2020-11-10 20:42:01 +01:00
timer-armada-370-xp.c clocksource/drivers/armada-370-xp: Use semicolons rather than commas to separate statements 2020-10-02 16:27:28 +02:00
timer-atcpit100.c clocksource/drivers: Set clockevent device cpumask to cpu_possible_mask 2018-07-26 11:26:30 +02:00
timer-atmel-pit.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
timer-atmel-st.c clocksource/drivers/atmel-st: Remove useless 'status' 2020-04-15 10:57:15 +02:00
timer-atmel-tcb.c clocksource/drivers/timer-atmel-tcb: Fix initialization on SAM9 hardware 2023-11-28 16:56:15 +00:00
timer-cadence-ttc.c clocksource/drivers/cadence-ttc: Fix memory leak in ttc_timer_probe 2023-07-23 13:46:45 +02:00
timer-clint.c clocksource: clint: Export clint_time_val for modules 2020-09-29 23:55:27 -07:00
timer-cs5535.c clocksource/drivers/timer-cs5535: Request irq with non-NULL dev_id 2020-03-12 19:23:06 +01:00
timer-davinci.c clocksource/drivers/davinci: Fix memory leak in davinci_timer_register when init fails 2023-05-11 23:00:37 +09:00
timer-digicolor.c clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 2017-06-14 11:58:45 +02:00
timer-fsl-ftm.c timekeeping, clocksource: Fix various typos in comments 2021-03-22 23:06:48 +01:00
timer-fttmr010.c clocksource/drivers/fttmr010: Pass around less pointers 2021-08-14 10:49:49 +02:00
timer-gx6605s.c clocksource/drivers/timer-gx6605s: Fixup counter reload 2020-08-24 13:01:39 +02:00
timer-imx-gpt.c clocksource/drivers/timer-imx-gpt: Fix potential memory leak 2023-11-28 16:56:15 +00:00
timer-imx-sysctr.c clocksource/drivers/imx-sysctr: Remove unused includes 2020-03-17 10:11:45 +01:00
timer-imx-tpm.c clocksource/drivers/imx-tpm: Fix next event not taking effect sometime 2024-09-12 11:07:51 +02:00
timer-integrator-ap.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
timer-ixp4xx.c clocksource/drivers/ixp4xx: remove EXPORT_SYMBOL_GPL from ixp4xx_timer_setup() 2022-07-07 17:53:32 +02:00
timer-keystone.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
timer-lpc32xx.c clocksource/drivers: Unify the names to timer-* format 2018-10-03 14:37:02 +02:00
timer-mediatek.c clocksource/drivers/mediatek: Optimize systimer irq clear flow on shutdown 2021-08-14 02:44:35 +02:00
timer-meson6.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
timer-microchip-pit64b.c clocksource/drivers/timer-microchip-pit64b: Use notrace 2022-04-08 14:23:08 +02:00
timer-milbeaut.c clocksource/drivers/timer-milbeaut: Cleanup common register accesses 2019-05-02 21:55:58 +02:00
timer-mp-csky.c clocksource/drivers/c-sky: fixup ftrace call-graph panic 2018-12-31 23:17:23 +08:00
timer-npcm7xx.c clocksource/drivers/npcm: Add support for WPCM450 2021-04-08 13:24:16 +02:00
timer-of.c clocksource/drivers/timer-of: Remove percpu irq related code 2024-09-12 11:07:51 +02:00
timer-of.h clocksource/drivers/timer-of: Remove percpu irq related code 2024-09-12 11:07:51 +02:00
timer-orion.c clocksource/drivers/orion: Add missing clk_disable_unprepare() on error path 2020-12-03 19:16:26 +01:00
timer-owl.c clocksource/drivers/owl: Improve owl_timer_init fail messages 2020-02-27 09:42:00 +01:00
timer-oxnas-rps.c clocksource/drivers/oxnas-rps: Fix irq_of_parse_and_map() return value 2022-06-14 18:36:09 +02:00
timer-pistachio.c clocksource/drivers/pistachio: Fix trivial typo 2021-04-08 13:24:15 +02:00
timer-probe.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
timer-pxa.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
timer-qcom.c clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init() 2024-10-17 15:10:49 +02:00
timer-rda.c clocksource/drivers/rda: Add clock driver for RDA8810PL SoC 2018-12-18 22:22:23 +01:00
timer-riscv.c Revert "clocksource/drivers/riscv: Events are stopped during CPU suspend" 2022-12-08 11:28:45 +01:00
timer-rockchip.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
timer-sp.h clocksource/drivers/sp804: Enable Hisilicon sp804 timer 64bit mode 2020-09-24 10:51:04 +02:00
timer-sp804.c clocksource/drivers/sp804: Avoid error on multiple instances 2022-06-14 18:36:22 +02:00
timer-sprd.c clocksource/drivers/sprd: Register one always-on timer to compensate suspend time 2018-07-26 11:26:34 +02:00
timer-stm32-lp.c clocksource: Add Low Power STM32 timers driver 2020-06-18 11:19:58 +01:00
timer-stm32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
timer-sun4i.c clocksource: sun4i: Add missing compatibles 2019-08-27 00:31:39 +02:00
timer-sun5i.c clocksource/drivers/sun5i: Fail gracefully when clock rate is unavailable 2019-02-23 12:13:45 +01:00
timer-tegra.c clocksource/drivers/tegra: Set up maximum-ticks limit properly 2019-06-25 19:49:18 +02:00
timer-ti-32k.c clocksource/drivers: Replace HTTP links with HTTPS ones 2020-07-23 16:57:43 +02:00
timer-ti-dm-systimer.c clocksource/drivers/timer-ti-dm: Fix missing clk_disable_unprepare in dmtimer_systimer_init_clock() 2022-12-31 13:14:04 +01:00
timer-ti-dm.c clocksource/drivers/timer-ti-dm: Drop unnecessary restore 2021-06-16 17:33:04 +02:00
timer-versatile.c clocksource/drivers/timer-versatile: Clear OF_POPULATED flag 2020-05-23 00:03:25 +02:00
timer-vf-pit.c timekeeping, clocksource: Fix various typos in comments 2021-03-22 23:06:48 +01:00
timer-vt8500.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00
timer-zevio.c clocksource: Replace setup_irq() by request_irq() 2020-02-27 12:15:24 +01:00