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

			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

  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

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>;

};

* 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>;

	};

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)