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2020-08-06vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()Thomas Gleixner
MIPS already uses and S390 will need the vdso data pointer in __arch_get_hw_counter(). This works nicely as long as the architecture does not support time namespaces in the VDSO. With time namespaces enabled the regular accessor to the vdso data pointer __arch_get_vdso_data() will return the namespace specific VDSO data page for tasks which are part of a non-root time namespace. This would cause the architectures which need the vdso data pointer in __arch_get_hw_counter() to access the wrong vdso data page. Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in from the call sites in the core code. For architectures which do not need the data pointer in their counter accessor function the compiler will just optimize it out. Fix up all existing architecture implementations and make MIPS utilize the pointer instead of invoking the accessor function. No functional change and no change in the resulting object code (except MIPS). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de
2020-07-21asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h'Will Deacon
Now that 'smp_read_barrier_depends()' has gone the way of the Norwegian Blue, drop the inclusion of <asm/barrier.h> in 'asm-generic/rwonce.h'. This requires fixups to some architecture vdso headers which were previously relying on 'asm/barrier.h' coming in via 'linux/compiler.h'. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-03-21arm: vdso: Enable arm to use common headersVincenzo Frascino
Enable arm to use only the common headers in the implementation of the vDSO library. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@armlinux.org.uk> Link: https://lkml.kernel.org/r/20200320145351.32292-25-vincenzo.frascino@arm.com
2020-03-21arm: Introduce asm/vdso/clocksource.hVincenzo Frascino
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 <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@armlinux.org.uk> Link: https://lkml.kernel.org/r/20200320145351.32292-6-vincenzo.frascino@arm.com
2020-02-17lib/vdso: Avoid highres update if clocksource is not VDSO capableThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de
2020-02-17ARM/arm64: vdso: Use common vdso clock mode storageThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de
2020-02-17ARM: vdso: Compile high resolution parts conditionallyThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de
2020-02-17ARM: vdso: Remove unused functionThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de
2020-01-27Merge tag 'timers-core-2020-01-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2020-01-17lib/vdso: Make __arch_update_vdso_data() logic understandableThomas Gleixner
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 <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de
2020-01-14ARM: vdso: Set BUILD_VDSO32 and provide 32bit fallbacksThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/87tv4zq9dc.fsf@nanos.tec.linutronix.de
2019-12-06ARM: 8947/1: Fix __arch_get_hw_counter() access to CNTVCTVincenzo Frascino
__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 <arnd@arndb.de> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15ARM: 8931/1: Add clock_getres entry pointVincenzo Frascino
The generic vDSO library provides an implementation of clock_getres() that can be leveraged by each architecture. Add clock_getres() entry point on arm to be on pair with arm64. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15ARM: 8930/1: Add support for generic vDSOVincenzo Frascino
The arm vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday - Implementation of elf note Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>