summaryrefslogtreecommitdiffstats
path: root/arch/openrisc/kernel/time.c
AgeCommit message (Collapse)AuthorFilesLines
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 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 as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-03openrisc: add tick timer multi-core sync logicStafford Horne1-2/+13
In case timers are not in sync when cpus start (i.e. hot plug / offset resets) we need to synchronize the secondary cpus internal timer with the main cpu. This is needed as in OpenRISC SMP there is only one clocksource registered which reads from the same ttcr register on each cpu. This synchronization routine heavily borrows from mips implementation that does something similar. Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-11-03openrisc: initial SMP supportStefan Kristiansson1-20/+31
This patch introduces the SMP support for the OpenRISC architecture. The SMP architecture requires cores which have multi-core features which have been introduced a few years back including: - New SPRS SPR_COREID SPR_NUMCORES - Shadow SPRs - Atomic Instructions - Cache Coherency - A wired in IPI controller This patch adds all of the SMP specific changes to core infrastructure, it looks big but it needs to go all together as its hard to split this one up. Boot loader spinning of second cpu is not supported yet, it's assumed that Linux is booted straight after cpu reset. The bulk of these changes are trivial changes to refactor to use per cpu data structures throughout. The addition of the smp.c and changes in time.c are the changes. Some specific notes: MM changes ---------- The reason why this is created as an array, and not with DEFINE_PER_CPU is that doing it this way, we'll save a load in the tlb-miss handler (the load from __per_cpu_offset). TLB Flush --------- The SMP implementation of flush_tlb_* works by sending out a function-call IPI to all the non-local cpus by using the generic on_each_cpu() function. Currently, all flush_tlb_* functions will result in a flush_tlb_all(), which has always been the behaviour in the UP case. CPU INFO -------- This creates a per cpu cpuinfo struct and fills it out accordingly for each activated cpu. show_cpuinfo is also updated to reflect new version information in later versions of the spec. SMP API ------- This imitates the arm64 implementation by having a smp_cross_call callback that can be set by set_smp_cross_call to initiate an IPI and a handle_IPI function that is expected to be called from an IPI irqchip driver. Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> [shorne@gmail.com: added cpu stop, checkpatch fixes, wrote commit message] Signed-off-by: Stafford Horne <shorne@gmail.com>
2016-12-25clocksource: Use a plain u64 instead of cycle_tThomas Gleixner1-2/+2
There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org>
2015-08-10openrisc/time: Migrate to new 'set-state' interfaceViresh Kumar1-24/+0
Migrate openrisc driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. We weren't doing anything in the ->set_mode() callback. So, this patch doesn't provide any set-state callbacks. Cc: Jonas Bonn <jonas@southpole.se> Cc: linux@lists.openrisc.net Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2012-02-17openrisc: Set shortest clock event to 100 ticksJonas Bonn1-8/+5
It takes a couple of instructions to actually configure a clock event so setting an alarm just 1 clock cycle in the future isn't going to work; doing so results in setting an alarm in the "past" in which case the event won't fire until the timer overflows and rolls back around to the "current time". Not quite sure how many clock cycles it actually takes to get through to actually writing the register, but 100 seems to work reliably. Use generic helper to set up the clock event while we're at it. Reported-by: Jan Schulte <jan.schulte@aacmicrotec.com> Signed-off-by: Jonas Bonn <jonas@southpole.se>
2011-07-22OpenRISC: TimekeepingJonas Bonn1-0/+181
Implements support for the OpenRISC timer which is a 28 bit cycle counter that can be read out of a special purpose register. This counter is used as a both a clock event and clocksource device. Signed-off-by: Jonas Bonn <jonas@southpole.se> Cc: tglx@linutronix.de Reviewed-by: Arnd Bergmann <arnd@arndb.de>