linux.git/arch/arm/include/asm/vdso, branch v5.8

arm: vdso: Enable arm to use common headers

2020-03-21T14:24:03+00:00

Enable arm to use only the common headers in the implementation
of the vDSO library.

Signed-off-by: Vincenzo Frascino 
Signed-off-by: Thomas Gleixner 
Cc: Russell King 
Link: https://lkml.kernel.org/r/20200320145351.32292-25-vincenzo.frascino@arm.com

arm: Introduce asm/vdso/clocksource.h

2020-03-21T14:23:54+00:00

The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.

Introduce asm/vdso/clocksource.h to contain all the arm64 specific
functions that are suitable for vDSO inclusion.

This header will be required by a future patch that will generalize
vdso/clocksource.h.

Signed-off-by: Vincenzo Frascino 
Signed-off-by: Thomas Gleixner 
Cc: Russell King 
Link: https://lkml.kernel.org/r/20200320145351.32292-6-vincenzo.frascino@arm.com

lib/vdso: Avoid highres update if clocksource is not VDSO capable

2020-02-17T19:12:17+00:00

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Reviewed-by: Vincenzo Frascino 
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de

ARM/arm64: vdso: Use common vdso clock mode storage

2020-02-17T19:12:16+00:00

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Reviewed-by: Vincenzo Frascino 
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de

ARM: vdso: Compile high resolution parts conditionally

2020-02-17T13:40:21+00:00

If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Reviewed-by: Vincenzo Frascino 
Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de

ARM: vdso: Remove unused function

2020-02-17T13:40:20+00:00

The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Reviewed-by: Vincenzo Frascino 
Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de

Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-01-28T00:47:05+00:00

Pull timer updates from Thomas Gleixner:
 "The timekeeping and timers departement provides:

   - Time namespace support:

     If a container migrates from one host to another then it expects
     that clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime
     these clocks can differ significantly on two hosts, in the worst
     case time goes backwards which is a violation of the POSIX
     requirements.

     The time namespace addresses this problem. It allows to set offsets
     for clock MONOTONIC and BOOTTIME once after creation and before
     tasks are associated with the namespace. These offsets are taken
     into account by timers and timekeeping including the VDSO.

     Offsets for wall clock based clocks (REALTIME/TAI) are not provided
     by this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric
     potential use cases which were discussed at Plumbers '18.

     The overhead for tasks in the root namespace (ie where host time
     offsets = 0) is in the noise and great effort was made to ensure
     that especially in the VDSO. If time namespace is disabled in the
     kernel configuration the code is compiled out.

     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
     feature and kept on for more than a year addressing review
     comments, finding better solutions. A pleasant experience.

   - Overhaul of the alarmtimer device dependency handling to ensure
     that the init/suspend/resume ordering is correct.

   - A new clocksource/event driver for Microchip PIT64

   - Suspend/resume support for the Hyper-V clocksource

   - The usual pile of fixes, updates and improvements mostly in the
     driver code"

* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
  alarmtimer: Use wakeup source from alarmtimer platform device
  alarmtimer: Make alarmtimer platform device child of RTC device
  alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
  hrtimer: Add missing sparse annotation for __run_timer()
  lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
  MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
  clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
  clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
  clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
  clocksource/drivers/exynos_mct: Rename Exynos to lowercase
  clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
  clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
  clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
  clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
  clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
  clocksource/drivers/bcm2835_timer: Fix memory leak of timer
  clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
  clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
  clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
  ...

lib/vdso: Make __arch_update_vdso_data() logic understandable

2020-01-17T14:53:50+00:00

The function name suggests that this is a boolean checking whether the
architecture asks for an update of the VDSO data, but it works the other
way round. To spare further confusion invert the logic.

Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de

ARM: vdso: Set BUILD_VDSO32 and provide 32bit fallbacks

2020-01-14T11:20:43+00:00

Setting BUILD_VDSO32 is required to expose the legacy 32bit interfaces in
the generic VDSO code which are going to be hidden behind an #ifdef
BUILD_VDSO32.

The 32bit fallbacks are necessary to remove the existing
VDSO_HAS_32BIT_FALLBACK hackery.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/87tv4zq9dc.fsf@nanos.tec.linutronix.de

ARM: 8947/1: Fix __arch_get_hw_counter() access to CNTVCT

2019-12-06T11:51:03+00:00

__arch_get_hw_counter() should check clock_mode to see if it can access
CNTVCT. With the conversion to unified vDSO this check has been left out.

This causes on imx v6 and v7 (imx_v6_v7_defconfig) and other platforms to
hang at boot during the execution of the init process as per below:

[   19.976852] Run /sbin/init as init process
[   20.044931] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000004

Fix the problem verifying that clock_mode is set coherently before
accessing CNTVCT.

Investigated-by: Arnd Bergmann 

Reported-by: Guenter Roeck 
Tested-by: Guenter Roeck 
Reviewed-by: Philippe Mathieu-Daudé 
Signed-off-by: Vincenzo Frascino 
Signed-off-by: Russell King