#
9025cebf |
|
30-Aug-2022 |
Joey Gouly <joey.gouly@arm.com> |
arm64: vdso: use SYS_CNTVCTSS_EL0 for gettimeofday If FEAT_ECV is implemented, the self-synchronized counter CNTVCTSS_EL0 can be used, removing the need for an ISB. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20220830104833.34636-4-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
#
808094fc |
|
31-Mar-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data() For the same reason as commit e876f0b69dc9 ("lib/vdso: Allow architectures to provide the vdso data pointer"), powerpc wants to avoid calculation of relative position to code. As the timens_vdso_data is next page to vdso_data, provide vdso_data pointer to __arch_get_timens_vdso_data() in order to ease the calculation on powerpc in following patches. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/539c4204b1baa77c55f758904a1ea239abbc7a5c.1617209142.git.christophe.leroy@csgroup.eu
|
#
77ec4625 |
|
18-Mar-2021 |
Will Deacon <will@kernel.org> |
arm64: vdso: Avoid ISB after reading from cntvct_el0 We can avoid the expensive ISB instruction after reading the counter in the vDSO gettime functions by creating a fake address hazard against a dummy stack read, just like we do inside the kernel. Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20210318170738.7756-5-will@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
#
4c5a116a |
|
04-Aug-2020 |
Thomas Gleixner <tglx@linutronix.de> |
vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter() 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
|
#
3503d56c |
|
24-Jun-2020 |
Andrei Vagin <avagin@gmail.com> |
arm64/vdso: Add time namespace page Allocate the time namespace page among VVAR pages. Provide __arch_get_timens_vdso_data() helper for VDSO code to get the code-relative position of VVARs on that special page. If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the VDSO data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. The time-namespace page isn't allocated on !CONFIG_TIME_NAMESPACE, but vma is the same size, which simplifies criu/vdso migration between different kernel configs. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200624083321.144975-4-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
#
002dff36 |
|
10-Jul-2020 |
Will Deacon <will@kernel.org> |
asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h' 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>
|
#
60ad903e |
|
20-Mar-2020 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: vdso: Include common headers in the vdso library 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. Refactor the vdso implementation to include common headers. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200320145351.32292-21-vincenzo.frascino@arm.com
|
#
5e3c6a31 |
|
07-Feb-2020 |
Thomas Gleixner <tglx@linutronix.de> |
ARM/arm64: vdso: Use common vdso clock mode storage 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
|
#
27e11a9f |
|
25-Jun-2019 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: Fix __arch_get_hw_counter() implementation Provide the following fixes for the __arch_get_hw_counter() implementation on arm64: - Fallback on syscall when an unstable counter is detected. - Introduce isb()s before and after the counter read to avoid speculation of the counter value and of the seq lock respectively. The second isb() is a temporary solution that will be revisited in 5.3-rc1. These fixes restore the semantics that __arch_counter_get_cntvct() had on arm64. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: catalin.marinas@arm.com Cc: will.deacon@arm.com Cc: arnd@arndb.de Cc: linux@armlinux.org.uk Cc: ralf@linux-mips.org Cc: paul.burton@mips.com Cc: daniel.lezcano@linaro.org Cc: salyzyn@android.com Cc: pcc@google.com Cc: shuah@kernel.org Cc: 0x7f454c46@gmail.com Cc: linux@rasmusvillemoes.dk Cc: huw@codeweavers.com Cc: sthotton@marvell.com Cc: andre.przywara@arm.com Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190625161804.38713-2-vincenzo.frascino@arm.com
|
#
28b1a824 |
|
21-Jun-2019 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: vdso: Substitute gettimeofday() with C implementation To take advantage of the commonly defined vdso interface for gettimeofday() the architectural code requires an adaptation. Re-implement the gettimeofday VDSO in C in order to use lib/vdso. With the new implementation arm64 gains support for CLOCK_BOOTTIME and CLOCK_TAI. [ tglx: Reformatted the function line breaks ] Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-5-vincenzo.frascino@arm.com
|