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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-20 10:06:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-20 10:06:32 -0800
commit20dcfe1b7df4072a3c13bdb7506f7138125d0099 (patch)
treeb7a206aeb59240622a5f24e2c54f3d98c37caba2 /Documentation
parentc9b9f207b90468bf9583f7ed71c15d0142bbf9b1 (diff)
parent336a9cde10d641e70bac67d90ae91b3190c3edca (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')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt9
-rw-r--r--Documentation/devicetree/bindings/arm/arch_timer.txt6
-rw-r--r--Documentation/devicetree/bindings/timer/cortina,gemini-timer.txt22
-rw-r--r--Documentation/devicetree/bindings/timer/renesas,ostm.txt30
-rw-r--r--Documentation/timers/timer_stats.txt73
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)
-