kernel/linux.git/drivers/clocksource, branch v4.19.16

clocksource/drivers/arc_timer: Utilize generic sched_clock

2019-01-09T16:38:42+00:00

commit bf287607c80f24387fedb431a346dc67f25be12c upstream. It turned out we used to use default implementation of sched_clock() from kernel/sched/clock.c which was as precise as 1/HZ, i.e. by default we had 10 msec granularity of time measurement. Now given ARC built-in timers are clocked with the same frequency as CPU cores we may get much higher precision of time tracking. Thus we switch to generic sched_clock which really reads ARC hardware counters. This is especially helpful for measuring short events. That's what we used to have: ------------------------------>8------------------------ $ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello': 10.000000 task-clock (msec) # 2.832 CPUs utilized 1 context-switches # 0.100 K/sec 1 cpu-migrations # 0.100 K/sec 63 page-faults # 0.006 M/sec 3049480 cycles # 0.305 GHz 1091259 instructions # 0.36 insn per cycle 256828 branches # 25.683 M/sec 27026 branch-misses # 10.52% of all branches 0.003530687 seconds time elapsed 0.000000000 seconds user 0.010000000 seconds sys ------------------------------>8------------------------ And now we'll see: ------------------------------>8------------------------ $ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello': 3.004322 task-clock (msec) # 0.865 CPUs utilized 1 context-switches # 0.333 K/sec 1 cpu-migrations # 0.333 K/sec 63 page-faults # 0.021 M/sec 2986734 cycles # 0.994 GHz 1087466 instructions # 0.36 insn per cycle 255209 branches # 84.947 M/sec 26002 branch-misses # 10.19% of all branches 0.003474829 seconds time elapsed 0.003519000 seconds user 0.000000000 seconds sys ------------------------------>8------------------------ Note how much more meaningful is the second output - time spent for execution pretty much matches number of cycles spent (we're runnign @ 1GHz here). Signed-off-by: Alexey Brodkin Cc: Daniel Lezcano Cc: Vineet Gupta Cc: Thomas Gleixner Cc: stable@vger.kernel.org Acked-by: Vineet Gupta Signed-off-by: Daniel Lezcano Signed-off-by: Greg Kroah-Hartman

clockevents/drivers/i8253: Add support for PIT shutdown quirk

2018-11-21T08:19:20+00:00

commit 35b69a420bfb56b7b74cb635ea903db05e357bec upstream. Add support for platforms where pit_shutdown() doesn't work because of a quirk in the PIT emulation. On these platforms setting the counter register to zero causes the PIT to start running again, negating the shutdown. Provide a global variable that controls whether the counter register is zero'ed, which platform specific code can override. Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Cc: "gregkh@linuxfoundation.org" Cc: "devel@linuxdriverproject.org" Cc: "daniel.lezcano@linaro.org" Cc: "virtualization@lists.linux-foundation.org" Cc: "jgross@suse.com" Cc: "akataria@vmware.com" Cc: "olaf@aepfle.de" Cc: "apw@canonical.com" Cc: vkuznets Cc: "jasowang@redhat.com" Cc: "marcelo.cerri@canonical.com" Cc: KY Srinivasan Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1541303219-11142-2-git-send-email-mikelley@microsoft.com Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/timer-atmel-pit: Properly handle error cases

2018-09-27T10:01:45+00:00

The smatch utility reports a possible leak: smatch warnings: drivers/clocksource/timer-atmel-pit.c:183 at91sam926x_pit_dt_init() warn: possible memory leak of 'data' Ensure data is freed before exiting with an error. Reported-by: Dan Carpenter Signed-off-by: Alexandre Belloni Cc: stable@vger.kernel.org Signed-off-by: Daniel Lezcano

clocksource/drivers/fttmr010: Fix set_next_event handler

2018-09-24T04:13:31+00:00

Currently, the aspeed MATCH1 register is updated to in set_next_event handler, with the assumption that COUNT register value is preserved when the timer is disabled and it continues decrementing after the timer is enabled. But the assumption is wrong: RELOAD register is loaded into COUNT register when the aspeed timer is enabled, which means the next event may be delayed because timer interrupt won't be generated until <0xFFFFFFFF - current_count + cycles>. The problem can be fixed by updating RELOAD register to , and COUNT register will be re-loaded when the timer is enabled and interrupt is generated when COUNT register overflows. The test result on Facebook Backpack-CMM BMC hardware (AST2500) shows the issue is fixed: without the patch, usleep(100) suspends the process for several milliseconds (and sometimes even over 40 milliseconds); after applying the fix, usleep(100) takes averagely 240 microseconds to return under the same workload level. Signed-off-by: Tao Ren Reviewed-by: Linus Walleij Tested-by: Lei YU Signed-off-by: Daniel Lezcano

clocksource/drivers/ti-32k: Add CLOCK_SOURCE_SUSPEND_NONSTOP flag for non-am43 SoCs

2018-09-13T13:23:35+00:00

The 32k clocksource is NONSTOP for non-am43 SoCs. Hence add the flag for all the other SoCs. Reported-by: Tony Lindgren Signed-off-by: Keerthy Acked-by: Tony Lindgren Signed-off-by: Daniel Lezcano

Merge tag 'riscv-for-linus-4.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

2018-08-19T16:56:38+00:00

Pull RISC-V updates from Palmer Dabbelt: "This contains some major improvements to the RISC-V port, including the necessary interrupt controller and timer support to actually make it to userspace. Support for three devices has been added: - the ISA-mandated timers on RISC-V systems. - the ISA-mandated first-level interrupt controller on RISC-V systems, which is handled as part of our core arch code because it's very small and tightly tied to the ISA. - SiFive's platform-level interrupt controller, which talks to the actual devices. In addition to these new devices, there are a handful of cleanups all over the RISC-V tree: - build fixes for various configurations: * A fix to the vDSO build's makefile so it respects CFLAGS. * The addition of __lshrti3, a libgcc derived function necessary for some 32-bit configurations. * !SMP && PERF_EVENTS - Cleanups to the arch code to remove the remnants of old versions of the drivers that were just properly submitted. * Some dead code from the timer driver, most of which wasn't ever even compiled. * Cleanups of some interrupt #defines, which are now local to the interrupt handling code. - Fixes to ptrace(), which while not being sufficient to fully make GDB work are at least sufficient to get simple GDB tasks to work. - Early printk support via RISC-V's architecturally mandated SBI console device. - A fix to our early debug trap handler to ensure it's always aligned. These patches have all been through a fairly extensive review process, but as this enables a whole pile of functionality (ie, userspace) I'm confident we'll need to submit a few more patches. The only concrete issues I know about are the sys_riscv_flush_icache patches, but as I managed to screw those up on Friday I figured it'd be best to let them bake another week. This tag boots a Fedora root filesystem on QEMU's master branch for me, and before this morning's rebase (from 4.18-rc8 to 4.18) it booted on the HiFive Unleashed. Thanks to Christoph Hellwig and the other guys at WD for getting the new drivers in shape!" * tag 'riscv-for-linus-4.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: dt-bindings: interrupt-controller: SiFive Plaform Level Interrupt Controller dt-bindings: interrupt-controller: RISC-V local interrupt controller RISC-V: Fix !CONFIG_SMP compilation error irqchip: add a SiFive PLIC driver RISC-V: Add the directive for alignment of stvec's value clocksource: new RISC-V SBI timer driver RISC-V: implement low-level interrupt handling RISC-V: add a definition for the SIE SEIE bit RISC-V: remove INTERRUPT_CAUSE_* defines from asm/irq.h RISC-V: simplify software interrupt / IPI code RISC-V: remove timer leftovers RISC-V: Add early printk support via the SBI console RISC-V: Don't increment sepc after breakpoint. RISC-V: implement __lshrti3. RISC-V: Use KBUILD_CFLAGS instead of KCFLAGS when building the vDSO

Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-08-14T01:28:19+00:00

Pull x86 timer updates from Thomas Gleixner: "Early TSC based time stamping to allow better boot time analysis. This comes with a general cleanup of the TSC calibration code which grew warts and duct taping over the years and removes 250 lines of code. Initiated and mostly implemented by Pavel with help from various folks" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/kvmclock: Mark kvm_get_preset_lpj() as __init x86/tsc: Consolidate init code sched/clock: Disable interrupts when calling generic_sched_clock_init() timekeeping: Prevent false warning when persistent clock is not available sched/clock: Close a hole in sched_clock_init() x86/tsc: Make use of tsc_calibrate_cpu_early() x86/tsc: Split native_calibrate_cpu() into early and late parts sched/clock: Use static key for sched_clock_running sched/clock: Enable sched clock early sched/clock: Move sched clock initialization and merge with generic clock x86/tsc: Use TSC as sched clock early x86/tsc: Initialize cyc2ns when tsc frequency is determined x86/tsc: Calibrate tsc only once ARM/time: Remove read_boot_clock64() s390/time: Remove read_boot_clock64() timekeeping: Default boot time offset to local_clock() timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() s390/time: Add read_persistent_wall_and_boot_offset() x86/xen/time: Output xen sched_clock time from 0 x86/xen/time: Initialize pv xen time in init_hypervisor_platform() ...

clocksource: new RISC-V SBI timer driver

2018-08-13T15:31:31+00:00

The RISC-V ISA defines a per-hart real-time clock and timer, which is present on all systems. The clock is accessed via the 'rdtime' pseudo-instruction (which reads a CSR), and the timer is set via an SBI call. Contains various improvements from Atish Patra . Signed-off-by: Dmitriy Cherkasov Signed-off-by: Palmer Dabbelt [hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(), minor cleanups, merged hotplug cpu support and other improvements from Atish] Signed-off-by: Christoph Hellwig Acked-by: Thomas Gleixner Reviewed-by: Atish Patra Signed-off-by: Palmer Dabbelt

clocksource/drivers/arm_arch_timer: Fix bogus cpu_all_mask usage

2018-08-02T12:55:52+00:00

Using cpu_all_mask as target mask for clockevents is wrong as it never can actually target not possible CPUs. Use cpu_possible_mask instead Signed-off-by: Thomas Gleixner Cc: Sudeep Holla Cc: Daniel Lezcano

clocksource: ti-32k: Remove CLOCK_SOURCE_SUSPEND_NONSTOP flag

2018-08-02T11:35:08+00:00

Since commit 39232ed5a179 ("time: Introduce one suspend clocksource to compensate the suspend time") suspend/resume fails on AM437x platforms as the clocksource actually stops in suspend. Hence remove the CLOCK_SOURCE_SUSPEND_NONSTOP flag. Suggested-by: Grygorii Strashko Signed-off-by: Keerthy Signed-off-by: Thomas Gleixner Cc: Cc: Cc: Cc: Cc: Cc: Link: https://lkml.kernel.org/r/1533191716-20476-1-git-send-email-j-keerthy@ti.com