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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-20 10:06:32 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-20 10:06:32 -0800 |
commit | 20dcfe1b7df4072a3c13bdb7506f7138125d0099 (patch) | |
tree | b7a206aeb59240622a5f24e2c54f3d98c37caba2 /Documentation | |
parent | c9b9f207b90468bf9583f7ed71c15d0142bbf9b1 (diff) | |
parent | 336a9cde10d641e70bac67d90ae91b3190c3edca (diff) |
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Nothing exciting, just the usual pile of fixes, updates and cleanups:
- A bunch of clocksource driver updates
- Removal of CONFIG_TIMER_STATS and the related /proc file
- More posix timer slim down work
- A scalability enhancement in the tick broadcast code
- Math cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
hrtimer: Catch invalid clockids again
math64, tile: Fix build failure
clocksource/drivers/arm_arch_timer:: Mark cyclecounter __ro_after_init
timerfd: Protect the might cancel mechanism proper
timer_list: Remove useless cast when printing
time: Remove CONFIG_TIMER_STATS
clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101
clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure
clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameter
clocksource/drivers/arm_arch_timer: Add dt binding for hisilicon-161010101 erratum
clocksource/drivers/ostm: Add renesas-ostm timer driver
clocksource/drivers/ostm: Document renesas-ostm timer DT bindings
clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock
clocksource/drivers/gemini: Add driver for the Cortina Gemini
clocksource: add DT bindings for Cortina Gemini
clockevents: Add a clkevt-of mechanism like clksrc-of
tick/broadcast: Reduce lock cacheline contention
timers: Omit POSIX timer stuff from task_struct when disabled
x86/timer: Make delay() work during early bootup
delay: Add explanation of udelay() inaccuracy
...
Diffstat (limited to 'Documentation')
5 files changed, 58 insertions, 82 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index be7c0d9506b1..d8fc55aa9d44 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -549,15 +549,6 @@ loops can be debugged more effectively on production systems. - clocksource.arm_arch_timer.fsl-a008585= - [ARM64] - Format: <bool> - Enable/disable the workaround of Freescale/NXP - erratum A-008585. This can be useful for KVM - guests, if the guest device tree doesn't show the - erratum. If unspecified, the workaround is - enabled based on the device tree. - clearcpuid=BITNUM [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt index ad440a2b8051..e926aea1147d 100644 --- a/Documentation/devicetree/bindings/arm/arch_timer.txt +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -31,6 +31,12 @@ to deliver its interrupts via SPIs. This also affects writes to the tval register, due to the implicit counter read. +- hisilicon,erratum-161010101 : A boolean property. Indicates the + presence of Hisilicon erratum 161010101, which says that reading the + counters is unreliable in some cases, and reads may return a value 32 + beyond the correct value. This also affects writes to the tval + registers, due to the implicit counter read. + ** Optional properties: - arm,cpu-registers-not-fw-configured : Firmware does not initialize diff --git a/Documentation/devicetree/bindings/timer/cortina,gemini-timer.txt b/Documentation/devicetree/bindings/timer/cortina,gemini-timer.txt new file mode 100644 index 000000000000..16ea1d3b2e9e --- /dev/null +++ b/Documentation/devicetree/bindings/timer/cortina,gemini-timer.txt @@ -0,0 +1,22 @@ +Cortina Systems Gemini timer + +This timer is embedded in the Cortina Systems Gemini SoCs. + +Required properties: + +- compatible : Must be "cortina,gemini-timer" +- reg : Should contain registers location and length +- interrupts : Should contain the three timer interrupts with + flags for rising edge +- syscon : a phandle to the global Gemini system controller + +Example: + +timer@43000000 { + compatible = "cortina,gemini-timer"; + reg = <0x43000000 0x1000>; + interrupts = <14 IRQ_TYPE_EDGE_RISING>, /* Timer 1 */ + <15 IRQ_TYPE_EDGE_RISING>, /* Timer 2 */ + <16 IRQ_TYPE_EDGE_RISING>; /* Timer 3 */ + syscon = <&syscon>; +}; diff --git a/Documentation/devicetree/bindings/timer/renesas,ostm.txt b/Documentation/devicetree/bindings/timer/renesas,ostm.txt new file mode 100644 index 000000000000..be3ae0fdf775 --- /dev/null +++ b/Documentation/devicetree/bindings/timer/renesas,ostm.txt @@ -0,0 +1,30 @@ +* Renesas OS Timer (OSTM) + +The OSTM is a multi-channel 32-bit timer/counter with fixed clock +source that can operate in either interval count down timer or free-running +compare match mode. + +Channels are independent from each other. + +Required Properties: + + - compatible: must be one or more of the following: + - "renesas,r7s72100-ostm" for the r7s72100 OSTM + - "renesas,ostm" for any OSTM + This is a fallback for the above renesas,*-ostm entries + + - reg: base address and length of the register block for a timer channel. + + - interrupts: interrupt specifier for the timer channel. + + - clocks: clock specifier for the timer channel. + +Example: R7S72100 (RZ/A1H) OSTM node + + ostm0: timer@fcfec000 { + compatible = "renesas,r7s72100-ostm", "renesas,ostm"; + reg = <0xfcfec000 0x30>; + interrupts = <GIC_SPI 102 IRQ_TYPE_EDGE_RISING>; + clocks = <&mstp5_clks R7S72100_CLK_OSTM0>; + power-domains = <&cpg_clocks>; + }; diff --git a/Documentation/timers/timer_stats.txt b/Documentation/timers/timer_stats.txt deleted file mode 100644 index de835ee97455..000000000000 --- a/Documentation/timers/timer_stats.txt +++ /dev/null @@ -1,73 +0,0 @@ -timer_stats - timer usage statistics ------------------------------------- - -timer_stats is a debugging facility to make the timer (ab)usage in a Linux -system visible to kernel and userspace developers. If enabled in the config -but not used it has almost zero runtime overhead, and a relatively small -data structure overhead. Even if collection is enabled runtime all the -locking is per-CPU and lookup is hashed. - -timer_stats should be used by kernel and userspace developers to verify that -their code does not make unduly use of timers. This helps to avoid unnecessary -wakeups, which should be avoided to optimize power consumption. - -It can be enabled by CONFIG_TIMER_STATS in the "Kernel hacking" configuration -section. - -timer_stats collects information about the timer events which are fired in a -Linux system over a sample period: - -- the pid of the task(process) which initialized the timer -- the name of the process which initialized the timer -- the function where the timer was initialized -- the callback function which is associated to the timer -- the number of events (callbacks) - -timer_stats adds an entry to /proc: /proc/timer_stats - -This entry is used to control the statistics functionality and to read out the -sampled information. - -The timer_stats functionality is inactive on bootup. - -To activate a sample period issue: -# echo 1 >/proc/timer_stats - -To stop a sample period issue: -# echo 0 >/proc/timer_stats - -The statistics can be retrieved by: -# cat /proc/timer_stats - -While sampling is enabled, each readout from /proc/timer_stats will see -newly updated statistics. Once sampling is disabled, the sampled information -is kept until a new sample period is started. This allows multiple readouts. - -Sample output of /proc/timer_stats: - -Timerstats sample period: 3.888770 s - 12, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) - 15, 1 swapper hcd_submit_urb (rh_timer_func) - 4, 959 kedac schedule_timeout (process_timeout) - 1, 0 swapper page_writeback_init (wb_timer_fn) - 28, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) - 22, 2948 IRQ 4 tty_flip_buffer_push (delayed_work_timer_fn) - 3, 3100 bash schedule_timeout (process_timeout) - 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) - 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) - 1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer) - 1, 2292 ip __netdev_watchdog_up (dev_watchdog) - 1, 23 events/1 do_cache_clean (delayed_work_timer_fn) -90 total events, 30.0 events/sec - -The first column is the number of events, the second column the pid, the third -column is the name of the process. The forth column shows the function which -initialized the timer and in parenthesis the callback function which was -executed on expiry. - - Thomas, Ingo - -Added flag to indicate 'deferrable timer' in /proc/timer_stats. A deferrable -timer will appear as follows - 10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) - |