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2020-07-20sched_clock: Expose struct clock_read_dataPeter Zijlstra1-0/+28
In order to support perf_event_mmap_page::cap_time features, an architecture needs, aside from a userspace readable counter register, to expose the exact clock data so that userspace can convert the counter register into a correct timestamp. Provide struct clock_read_data and two (seqcount) helpers so that architectures (arm64 in specific) can expose the numbers to userspace. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Link: https://lore.kernel.org/r/20200716051130.4359-2-leo.yan@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-20sched/clock: Move sched clock initialization and merge with generic clockPavel Tatashin1-3/+2
sched_clock_postinit() initializes a generic clock on systems where no other clock is provided. This function may be called only after timekeeping_init(). Rename sched_clock_postinit to generic_clock_inti() and call it from sched_clock_init(). Move the call for sched_clock_init() until after time_init(). Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-23-pasha.tatashin@oracle.com
2015-12-15time: Define dummy functions for the generic sched clockDaniel Lezcano1-3/+9
When we try to compile a clocksource driver with the COMPILE_TEST option, we can't select the GENERIC_SCHED_CLOCK because the sched_clock() symbol will be duplicated with the one defined for the x86. In order to fix that, we don't select the GENERIC_SCHED_CLOCK in the driver Kconfig's file but we define some empty functions for the different symbols in order to prevent the unresolved ones. This patch fixes the COMPILE_TEST option for the compile test coverage for the clocksource drivers. Without this patch, we can't add the COMPILE_TEST option for the clocksource drivers using the GENERIC_SCHED_CLOCK. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2014-04-23sched_clock: Remove deprecated setup_sched_clock() APIStephen Boyd1-1/+0
Remove the 32-bit only setup_sched_clock() API now that all users have been converted to the 64-bit friendly sched_clock_register(). Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-10-10sched_clock: Remove sched_clock_func() hookStephen Boyd1-2/+0
Nobody is using sched_clock_func() anymore now that sched_clock supports up to 64 bits. Remove the hook so that new code only uses sched_clock_register(). Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-07-30sched_clock: Add support for >32 bit sched_clockStephen Boyd1-0/+2
The ARM architected system counter has at least 56 usable bits. Add support for counters with more than 32 bits to the generic sched_clock implementation so we can increase the time between wakeups due to dealing with wrap-around on these devices while benefiting from the irqtime accounting and suspend/resume handling that the generic sched_clock code already has. On my system using 56 bits over 32 bits changes the wraparound time from a few minutes to an hour. For faster running counters (GHz range) this is even more important because we may not be able to execute the timer in time to deal with the wraparound if only 32 bits are used. We choose a maxsec value of 3600 seconds because we assume no system will go idle for more than an hour. In the future we may need to increase this value. Note: All users should switch over to the 64-bit read function so we can remove setup_sched_clock() in favor of sched_clock_register(). Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-06-13sched_clock: Make ARM's sched_clock generic for all architecturesStephen Boyd1-0/+21
Nothing about the sched_clock implementation in the ARM port is specific to the architecture. Generalize the code so that other architectures can use it by selecting GENERIC_SCHED_CLOCK. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [jstultz: Merge minor collisions with other patches in my tree] Signed-off-by: John Stultz <john.stultz@linaro.org>