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* MIPS: clockevent drivers: Set ->min_delta_ticks and ->max_delta_ticksNicolai Stange2017-04-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for making the clockevents core NTP correction aware, all clockevent device drivers must set ->min_delta_ticks and ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a clockevent device's rate is going to change dynamically and thus, the ratio of ns to ticks ceases to stay invariant. Make the MIPS arch's clockevent drivers initialize these fields properly. This patch alone doesn't introduce any change in functionality as the clockevents core still looks exclusively at the (untouched) ->min_delta_ns and ->max_delta_ns. As soon as this has changed, a followup patch will purge the initialization of ->min_delta_ns and ->max_delta_ns from these drivers. Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Keguang Zhang <keguang.zhang@gmail.com> Cc: John Crispin <john@phrozen.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* clocksource: Use a plain u64 instead of cycle_tThomas Gleixner2016-12-251-2/+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>
* MIPS: hpet: Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLESHuacai Chen2016-07-241-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At first, we prefer to use mips clockevent device, so we decrease the rating of hpet clockevent device. For hpet, if HPET_MIN_PROG_DELTA (minimum delta of hpet programming) is too small and HPET_MIN_CYCLES (threshold of -ETIME checking) is too large, then hpet_next_event() can easily return -ETIME. After commit c6eb3f70d44828 ("hrtimer: Get rid of hrtimer softirq") this will cause a RCU stall. So, HPET_MIN_PROG_DELTA must be sufficient that we don't re-trip the -ETIME check -- if we do, we will return -ETIME, forward the next event time, try to set it, return -ETIME again, and basically lock the system up. Meanwhile, HPET_MIN_CYCLES doesn't need to be too large, 16 cycles is enough. This solution is similar to commit f9eccf24615672 ("clocksource/drivers /vt8500: Increase the minimum delta"). By the way, this patch ensures hpet count/compare to be 32-bit long. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@imgtec.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13819/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Loongson64: Fix typoAndrea Gelmini2016-05-281-1/+1
| | | | | | | | | | | Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: chenhc@lemote.com Cc: viresh.kumar@linaro.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13322/ Patchwork: https://patchwork.linux-mips.org/patch/13332/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: hpet: Choose a safe value for the ETIME checkHuacai Chen2016-01-221-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is borrowed from x86 hpet driver and explaind below: Due to the overly intelligent design of HPETs, we need to workaround the problem that the compare value which we write is already behind the actual counter value at the point where the value hits the real compare register. This happens for two reasons: 1) We read out the counter, add the delta and write the result to the compare register. When a NMI hits between the read out and the write then the counter can be ahead of the event already. 2) The write to the compare register is delayed by up to two HPET cycles in AMD chipsets. We can work around this by reading back the compare register to make sure that the written value has hit the hardware. But that is bad performance wise for the normal case where the event is far enough in the future. As we already know that the write can be delayed by up to two cycles we can avoid the read back of the compare register completely if we make the decision whether the delta has elapsed already or not based on the following calculation: cmp = event - actual_count; If cmp is less than 64 HPET clock cycles, then we decide that the event has happened already and return -ETIME. That covers the above #1 and #2 problems which would cause a wait for HPET wraparound (~306 seconds). Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12162/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: loongson64/timer: Migrate to new 'set-state' interfaceViresh Kumar2015-09-031-46/+71
| | | | | | | | | | | | | | | | | | | | | | | | | Migrate loongson 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. [ralf@linux-mips.org: Folded in Viresh's followon fix.] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Huacai Chen <chenhc@lemote.com> Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com> Cc: Hongliang Tao <taohl@lemote.com> Cc: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-mips@linux-mips.org Cc: linaro-kernel@lists.linaro.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Patchwork: https://patchwork.linux-mips.org/patch/10608/ Patchwork: https://patchwork.linux-mips.org/patch/10883/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Loongson: Naming style cleanup and reworkHuacai Chen2015-06-211-0/+257
Currently, code of Loongson-2/3 is under loongson directory and code of Loongson-1 is under loongson1 directory. Besides, there are Kconfig options such as MACH_LOONGSON and MACH_LOONGSON1. This naming style is very ugly and confusing. Since Loongson-2/3 are both 64-bit general- purpose CPU while Loongson-1 is 32-bit SoC, we rename both file names and Kconfig symbols from loongson/loongson1 to loongson64/loongson32. [ralf@linux-mips.org: Resolve a number of simple conflicts.] Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Kelvin Cheung <keguang.zhang@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/9790/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>