summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/csrc-r4k.c
Commit message (Collapse)AuthorAgeFilesLines
* MIPS: Don't register r4k sched clock when CPUFREQ enabledHuacai Chen2016-07-241-1/+3
| | | | | | | | | | | | | | | Don't register r4k sched clock when CPUFREQ enabled because sched clock need a constant frequency. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@caviumnetworks.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/13820/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()Alex Smith2015-11-111-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add user-mode implementations of gettimeofday() and clock_gettime() to the VDSO. This is currently usable with 2 clocksources: the CP0 count register, which is accessible to user-mode via RDHWR on R2 and later cores, or the MIPS Global Interrupt Controller (GIC) timer, which provides a "user-mode visible" section containing a mirror of its counter registers. This section must be mapped into user memory, which is done below the VDSO data page. When a supported clocksource is not in use, the VDSO functions will return -ENOSYS, which causes libc to fall back on the standard syscall path. When support for neither of these clocksources is compiled into the kernel at all, the VDSO still provides clock_gettime(), as the coarse realtime/monotonic clocks can still be implemented. However, gettimeofday() is not provided in this case as nothing can be done without a suitable clocksource. This causes the symbol lookup to fail in libc and it will then always use the standard syscall path. This patch includes a workaround for a bug in QEMU which results in RDHWR on the CP0 count register always returning a constant (incorrect) value. A fix for this has been submitted, and the workaround can be removed after the fix has been in stable releases for a reasonable amount of time. A simple performance test which calls gettimeofday() 1000 times in a loop and calculates the average execution time gives the following results on a Malta + I6400 (running at 20MHz): - Syscall: ~31000 ns - VDSO (GIC): ~15000 ns - VDSO (CP0): ~9500 ns [markos.chandras@imgtec.com: - Minor code re-arrangements in order for mappings to be made in the order they appear to the process' address space. - Move do_{monotonic, realtime} outside of the MIPS_CLOCK_VSYSCALL ifdef - Use gic_get_usm_range so we can do the GIC mapping in the arch/mips/kernel/vdso instead of the GIC irqchip driver] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11338/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: csrc-r4k: Implement read_sched_clockDeng-Cheng Zhu2015-04-011-0/+8
| | | | | | | | | | | Use c0 count register for sched_clock source. This implementation will give high resolution cputime accounting. Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Cc: linux-mips@linux-mips.org Cc: macro@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9478/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* mips: convert to clocksource_register_hz/khzJohn Stultz2011-02-211-3/+1
| | | | | | | | This converts the mips clocksources to use clocksource_register_hz/khz CC: Ralf Baechle <ralf@linux-mips.org> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com>
* clocksource: pass clocksource to read() callbackMagnus Damm2009-04-211-1/+1
| | | | | | | | | | | | | | Pass clocksource pointer to the read() callback for clocksources. This allows us to share the callback between multiple instances. [hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods] [akpm@linux-foundation.org: cleanup] Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* MIPS: make cp0 counter clocksource/event usable as fallback.Manuel Lauss2009-01-111-1/+1
| | | | | | | | | | | | | | | | | | | The current mips clock build infrastructure lets a system only use either the MIPS cp0 counter or a SoC specific timer as a clocksource / clockevent device. This patch renames the core cp0 counter clocksource / clockevent functions from mips_* to r4k_* and updates the wrappers in asm-mips/time.h to call these renamed functions instead. Chips which can detect whether it is safe to use a chip-specific timer can now fall back on the cp0 counter if necessary and possible (e.g. Alchemy with a follow-on patch). Existing behaviour is not changed in any way. Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: csrc-r4k: Fix spelling mistake.Ralf Baechle2008-11-201-1/+1
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Clocksource: Only install r4k counter as clocksource if present.Ralf Baechle2008-03-121-1/+6
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Fix build.Ralf Baechle2007-12-011-1/+5
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Only build r4k clocksource for systems that work ok with it.Ralf Baechle2007-11-261-0/+29
In particular as-is it's not suited for multicore and mutiprocessors systems where there is on guarantee that the counter are synchronized or running from the same clock at all. This broke Sibyte and probably others since the "[MIPS] Handle R4000/R4400 mfc0 from count register." commit. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
OpenPOWER on IntegriCloud