Commit Graph

15 Commits

Author SHA1 Message Date
Linus Torvalds 84c2e17951 Timers and timekeeping updates:
Core code:
 
     - Make the NOHZ handling of the timekeeping/tick core more robust to
       prevent a rare jiffies update stall.
 
     - Handle softirqs in the NOHZ/idle case correctly
 
  Drivers:
 
     - Add support for event stream scaling of the 1GHz counter on ARM(64)
 
     - Correct an error code check in the timer-of layer
 
     - The usual cleanups and improvements all over the place
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Merge tag 'timers-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and timekeeping updates from Thomas Gleixner:
 "Core code:

   - Make the NOHZ handling of the timekeeping/tick core more robust to
     prevent a rare jiffies update stall.

   - Handle softirqs in the NOHZ/idle case correctly

  Drivers:

   - Add support for event stream scaling of the 1GHz counter on ARM(64)

   - Correct an error code check in the timer-of layer

   - The usual cleanups and improvements all over the place"

* tag 'timers-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  lib/irq_poll: Declare IRQ_POLL softirq vector as ksoftirqd-parking safe
  tick/rcu: Stop allowing RCU_SOFTIRQ in idle
  tick/rcu: Remove obsolete rcu_needs_cpu() parameters
  tick: Detect and fix jiffies update stall
  clocksource/drivers/timer-of: Check return value of of_iomap in timer_of_base_init()
  clocksource/drivers/timer-microchip-pit64b: Use 5MHz for clockevent
  clocksource/drivers/timer-microchip-pit64b: Use notrace
  clocksource/drivers/timer-microchip-pit64b: Remove mmio selection
  dt-bindings: timer: Tegra: Convert text bindings to yaml
  clocksource/drivers/imx-tpm: Move tpm_read_sched_clock() under CONFIG_ARM
  clocksource/drivers/arm_arch_timer: Use event stream scaling when available
  clocksource/drivers/exynos_mct: Increase the size of name array
  clocksource/drivers/exynos_mct: Bump up mct max irq number
  clocksource/drivers/exynos_mct: Remove mct interrupt index enum
  clocksource/drivers/exynos_mct: Handle DTS with higher number of interrupts
  clocksource/drivers/timer-ti-dm: Fix regression from errata i940 fix
  clocksource/drivers/imx-tpm: Exclude sched clock for ARM64
  clocksource: Add a Kconfig option for WATCHDOG_MAX_SKEW
  clocksource/drivers/imx-tpm: Update name of clkevt
  clocksource/drivers/imx-tpm: Add CLOCK_EVT_FEAT_DYNIRQ
  ...
2022-03-21 12:53:14 -07:00
Thomas Gleixner b166e52541 - Fix return error code check for the timer-of layer when getting
the base address (Guillaume Ranquet)
 
 - Remove MMIO dependency, add notrace annotation for sched_clock
   and increase the timer resolution for the Microchip
   PIT64b (Claudiu Beznea)
 
 - Convert DT bindings to yaml for the Tegra timer (David Heidelberg)
 
 - Fix compilation error on architecture other than ARM for the
   i.MX TPM (Nathan Chancellor)
 
 - Add support for the event stream scaling for 1GHz counter on
   the arch ARM timer (Marc Zyngier)
 
 - Support a higher number of interrupts by the Exynos MCT timer
   driver (Alim Akhtar)
 
 - Detect and prevent memory corruption when the specified number
   of interrupts in the DTS is greater than the array size in the
   code for the Exynos MCT timer (Krzysztof Kozlowski)
 
 - Fix regression from a previous errata fix on the TI DM
   timer (Drew Fustini)
 
 - Several fixes and code improvements for the i.MX TPM
   driver (Peng Fan)
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Merge tag 'timers-v5.18-rc1' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core

Pull clocksource/events updates from Daniel Lezcano:

  - Fix return error code check for the timer-of layer when getting
    the base address (Guillaume Ranquet)

  - Remove MMIO dependency, add notrace annotation for sched_clock
    and increase the timer resolution for the Microchip
    PIT64b (Claudiu Beznea)

  - Convert DT bindings to yaml for the Tegra timer (David Heidelberg)

  - Fix compilation error on architecture other than ARM for the
    i.MX TPM (Nathan Chancellor)

  - Add support for the event stream scaling for 1GHz counter on
    the arch ARM timer (Marc Zyngier)

  - Support a higher number of interrupts by the Exynos MCT timer
    driver (Alim Akhtar)

  - Detect and prevent memory corruption when the specified number
    of interrupts in the DTS is greater than the array size in the
    code for the Exynos MCT timer (Krzysztof Kozlowski)

  - Fix regression from a previous errata fix on the TI DM
    timer (Drew Fustini)

  - Several fixes and code improvements for the i.MX TPM
    driver (Peng Fan)

Link: https://lore.kernel.org/all/a8cd9be9-7d70-80df-2b74-1a8226a215e1@linaro.org
2022-03-14 10:18:17 +01:00
Drew Fustini bceaae3bac clocksource/drivers/timer-ti-dm: Fix regression from errata i940 fix
The existing fix for errata i940 causes a conflict for IPU2 which is
using timer 3 and 4. From arch/arm/boot/dts/dra7-ipu-dsp-common.dtsi:

  &ipu2 {
          mboxes = <&mailbox6 &mbox_ipu2_ipc3x>;
          ti,timers = <&timer3>;
          ti,watchdog-timers = <&timer4>, <&timer9>;
  };

The conflict was noticed when booting mainline on the BeagleBoard X15
which has a TI AM5728 SoC:

  remoteproc remoteproc1: 55020000.ipu is available
  remoteproc remoteproc1: powering up 55020000.ipu
  remoteproc remoteproc1: Booting fw image dra7-ipu2-fw.xem4
  omap-rproc 55020000.ipu: could not get timer platform device
  omap-rproc 55020000.ipu: omap_rproc_enable_timers failed: -19
  remoteproc remoteproc1: can't start rproc 55020000.ipu: -19

This change modifies the errata fix to instead use timer 15 and 16 which
resolves the timer conflict.

It does not appear to introduce any latency regression. Results from
cyclictest with original errata fix using dmtimer 3 and 4:

  # cyclictest --mlockall --smp --priority=80 --interval=200 --distance=0
  policy: fifo: loadavg: 0.02 0.03 0.05

  T: 0 ( 1449) P:80 I:200 C: 800368 Min:   0 Act:   32 Avg:   22 Max:  128
  T: 1 ( 1450) P:80 I:200 C: 800301 Min:   0 Act:   12 Avg:   23 Max:   70

The results after the change to dmtimer 15 and 16:

  # cyclictest --mlockall --smp --priority=80 --interval=200 --distance=0
  policy: fifo: loadavg: 0.36 0.19 0.07

  T: 0 ( 1711) P:80 I:200 C: 759599 Min:   0 Act:    6 Avg:   22 Max:  108
  T: 1 ( 1712) P:80 I:200 C: 759539 Min:   0 Act:   19 Avg:   23 Max:   79

Fixes: 25de4ce5ed ("clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940")
Link: https://lore.kernel.org/linux-omap/YfWsG0p6to3IJuvE@x1/
Suggested-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Link: https://lore.kernel.org/r/20220204053503.1409162-1-dfustini@baylibre.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2022-03-07 18:27:16 +01:00
Anthoine Bourgeois 8840f5460a ARM: dts: Use 32KiHz oscillator on devkit8000
Devkit8000 board seems to always used 32k_counter as clocksource.
Restore this behavior.

If clocksource is back to 32k_counter, timer12 is now the clockevent
source (as before) and timer2 is not longer needed here.

This commit fixes the same issue observed with commit 23885389db
("ARM: dts: Fix timer regression for beagleboard revision c") when sleep
is blocked until hitting keys over serial console.

Fixes: aba1ad05da ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support")
Fixes: e428e250fd ("ARM: dts: Configure system timers for omap3")
Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2022-02-18 10:08:45 +02:00
Tony Lindgren 23885389db ARM: dts: Fix timer regression for beagleboard revision c
Commit e428e250fd ("ARM: dts: Configure system timers for omap3")
caused a timer regression for beagleboard revision c where the system
clockevent stops working if omap3isp module is unloaded.

Turns out we still have beagleboard revisions a-b4 capacitor c70 quirks
applied that limit the usable timers for no good reason. This also affects
the power management as we use the system clock instead of the 32k clock
source.

Let's fix the issue by adding a new omap3-beagle-ab4.dts for the old timer
quirks. This allows us to remove the timer quirks for later beagleboard
revisions. We also need to update the related timer quirk check for the
correct compatible property.

Fixes: e428e250fd ("ARM: dts: Configure system timers for omap3")
Cc: linux-kernel@vger.kernel.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Reported-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2021-12-17 14:15:43 +02:00
Tony Lindgren 25de4ce5ed clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940
There is a timer wrap issue on dra7 for the ARM architected timer.
In a typical clock configuration the timer fails to wrap after 388 days.

To work around the issue, we need to use timer-ti-dm percpu timers instead.

Let's configure dmtimer3 and 4 as percpu timers by default, and warn about
the issue if the dtb is not configured properly.

Let's do this as a single patch so it can be backported to v5.8 and later
kernels easily. Note that this patch depends on earlier timer-ti-dm
systimer posted mode fixes, and a preparatory clockevent patch
"clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue".

For more information, please see the errata for "AM572x Sitara Processors
Silicon Revisions 1.1, 2.0":

https://www.ti.com/lit/er/sprz429m/sprz429m.pdf

The concept is based on earlier reference patches done by Tero Kristo and
Keerthy.

Cc: Keerthy <j-keerthy@ti.com>
Cc: Tero Kristo <kristo@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210323074326.28302-3-tony@atomide.com
2021-04-08 16:41:18 +02:00
Tony Lindgren 3efe7a878a clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue
There is a timer wrap issue on dra7 for the ARM architected timer.
In a typical clock configuration the timer fails to wrap after 388 days.

To work around the issue, we need to use timer-ti-dm timers instead.

Let's prepare for adding support for percpu timers by adding a common
dmtimer_clkevt_init_common() and call it from dmtimer_clockevent_init().
This patch makes no intentional functional changes.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210323074326.28302-2-tony@atomide.com
2021-04-08 16:15:54 +02:00
Tony Lindgren ac4daf7376 clocksource/drivers/timer-ti-dm: Add missing set_state_oneshot_stopped
To avoid spurious timer interrupts when KTIME_MAX is used, we need to
configure set_state_oneshot_stopped(). Although implementing this is
optional, it still affects things like power management for the extra
timer interrupt.

For more information, please see commit 8fff52fd50 ("clockevents:
Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state") and commit cf8c5009ee
("clockevents/drivers/arm_arch_timer: Implement
->set_state_oneshot_stopped()").

Fixes: 52762fbd1c ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210304072135.52712-4-tony@atomide.com
2021-04-08 13:23:47 +02:00
Tony Lindgren 212709926c clocksource/drivers/timer-ti-dm: Fix posted mode status check order
When the timer is configured in posted mode, we need to check the write-
posted status register (TWPS) before writing to the register.

We now check TWPS after the write starting with commit 52762fbd1c
("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource
support").

For example, in the TRM for am571x the following is documented in chapter
"22.2.4.13.1.1 Write Posting Synchronization Mode":

"For each register, a status bit is provided in the timer write-posted
 status (TWPS) register. In this mode, it is mandatory that software check
 this status bit before any write access. If a write is attempted to a
 register with a previous access pending, the previous access is discarded
 without notice."

The regression happened when I updated the code to use standard read/write
accessors for the driver instead of using __omap_dm_timer_load_start().
We have__omap_dm_timer_load_start() check the TWPS status correctly using
__omap_dm_timer_write().

Fixes: 52762fbd1c ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210304072135.52712-2-tony@atomide.com
2021-04-08 13:23:41 +02:00
Ingo Molnar 4bf07f6562 timekeeping, clocksource: Fix various typos in comments
Fix ~56 single-word typos in timekeeping & clocksource code comments.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org
2021-03-22 23:06:48 +01:00
Tony Lindgren 164805157f clocksource/drivers/timer-ti-dm: Do reset before enable
Commit 6cfcd5563b ("clocksource/drivers/timer-ti-dm: Fix suspend and
resume for am3 and am4") exposed a new issue for type2 dual mode timers
on at least omap5 where the clockevent will stop when the SoC starts
entering idle states during the boot.

Turns out we are wrongly first enabling the system timer and then
resetting it, while we must also re-enable it after reset. The current
sequence leaves the timer module in a partially initialized state. This
issue went unnoticed earlier with ti-sysc driver reconfiguring the timer
module until we fixed the issue of ti-sysc reconfiguring system timers.

Let's fix the issue by calling dmtimer_systimer_enable() from reset for
both type1 and type2 timers, and switch the order of reset and enable in
dmtimer_systimer_setup(). Let's also move dmtimer_systimer_enable() and
dmtimer_systimer_disable() to do this without adding forward declarations.

Fixes: 6cfcd5563b ("clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4")
Reported-by: H. Nikolaus Schaller" <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200817092428.6176-1-tony@atomide.com
2020-08-24 13:01:39 +02:00
Tony Lindgren 6cfcd5563b clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4
Carlos Hernandez <ceh@ti.com> reported that we now have a suspend and
resume regresssion on am3 and am4 compared to the earlier kernels. While
suspend and resume works with v5.8-rc3, we now get errors with rtcwake:

pm33xx pm33xx: PM: Could not transition all powerdomains to target state
...
rtcwake: write error

This is because we now fail to idle the system timer clocks that the
idle code checks and the error gets propagated to the rtcwake.

Turns out there are several issues that need to be fixed:

1. Ignore no-idle and no-reset configured timers for the ti-sysc
   interconnect target driver as otherwise it will keep the system timer
   clocks enabled

2. Toggle the system timer functional clock for suspend for am3 and am4
   (but not for clocksource on am3)

3. Only reconfigure type1 timers in dmtimer_systimer_disable()

4. Use of_machine_is_compatible() instead of of_device_is_compatible()
   for checking the SoC type

Fixes: 52762fbd1c ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support")
Reported-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200713162601.6829-1-tony@atomide.com
2020-07-21 15:48:33 +02:00
Colin Ian King ac593e62b0 clocksource/drivers/timer-ti-dm: Fix spelling mistake "detectt" -> "detect"
There is a spelling mistake in a pr_err message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200519224428.6195-1-colin.king@canonical.com
2020-05-23 00:01:35 +02:00
Tony Lindgren c177e29754 clocksource/drivers/timer-ti-dm: Fix warning for set but not used
We can get a warning for dmtimer_clocksource_init() with 'pa' set but
not used. This was used in the earlier revisions of the code but no
longer needed, so let's remove the unused pa and of_translate_address().
Let's also do it for dmtimer_clockevent_init() that has a similar issue.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200519155157.12804-1-tony@atomide.com
2020-05-23 00:01:05 +02:00
Tony Lindgren 52762fbd1c clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support
We can move the TI dmtimer clockevent and clocksource to live under
drivers/clocksource if we rely only on the clock framework, and handle
the module configuration directly in the clocksource driver based on the
device tree data.

This removes the early dependency with system timers to the interconnect
related code, and we can probe pretty much everything else later on at
the module_init level.

Let's first add a new driver for timer-ti-dm-systimer based on existing
arch/arm/mach-omap2/timer.c. Then let's start moving SoCs to probe with
device tree data while still keeping the old timer.c. And eventually we
can just drop the old timer.c.

Let's take the opportunity to switch to use readl/writel as pointed out
by Daniel Lezcano <daniel.lezcano@linaro.org>. This allows further
clean-up of the timer-ti-dm code the a lot of the shared helpers can
just become static to the non-syster related code.

Note the boards can optionally configure different timer source clocks
if needed with assigned-clocks and assigned-clock-parents.

Cc: linux-kernel@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200507172330.18679-3-tony@atomide.com
2020-05-23 00:01:04 +02:00