kernel/linux.git/arch/powerpc/include/asm/time.h, branch linux-6.12.y

powerpc: Remove core support for 40x

2024-06-28T12:28:47+00:00

Now that 40x platforms have gone, remove support for 40x in the core of powerpc arch. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/20240628121201.130802-4-mpe@ellerman.id.au

powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform

2022-09-05T04:14:27+00:00

dtl is the PAPR Dispatch Trace Log, which is entirely a pseries feature. The pseries platform alrady has a file dealing with the dtl, so move scanning for stolen time accounting there from kernel/time.c. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220902085316.2071519-5-npiggin@gmail.com

powerpc/time: Fix sparse warnings

2022-05-04T09:37:42+00:00

We found these warnings in arch/powerpc/kernel/time.c as follows: warning: symbol 'decrementer_max' was not declared. Should it be static? warning: symbol 'rtc_lock' was not declared. Should it be static? warning: symbol 'dtl_consumer' was not declared. Should it be static? Declare 'decrementer_max' in powerpc asm/time.h. Include linux/mc146818rtc.h in powerpc kernel/time.c where 'rtc_lock' is declared. And remove duplicated declaration of 'rtc_lock' in powerpc platforms/chrp/time.c because it has included linux/mc146818rtc.h. Move 'dtl_consumer' definition after "include " because it is declared there. Reported-by: Hulk Robot Signed-off-by: He Ying Reviewed-by: Christophe Leroy Reviewed-by: Alexandre Belloni Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210324090939.143477-1-heying24@huawei.com

powerpc/time: add API for KVM to re-arm the host timer/decrementer

2021-11-24T10:08:57+00:00

Rather than have KVM look up the host timer and fiddle with the irq-work internal details, have the powerpc/time.c code provide a function for KVM to re-arm the Linux timer code when exiting a guest. This is implementation has an improvement over existing code of marking a decrementer interrupt as soft-pending if a timer has expired, rather than setting DEC to a -ve value, which tended to cause host timers to take two interrupts (first hdec to exit the guest, then the immediate dec). Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211123095231.1036501-8-npiggin@gmail.com

KVM: PPC: Book3S HV P9: Use large decrementer for HDEC

2021-11-24T10:08:57+00:00

On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0, this could help reduce needless guest exits due to leftover exceptions on entering the guest. Signed-off-by: Nicholas Piggin Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211123095231.1036501-6-npiggin@gmail.com

KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read

2021-11-24T10:08:56+00:00

There is no need to save away the host DEC value, as it is derived from the host timer subsystem which maintains the next timer time, so it can be restored from there. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211123095231.1036501-5-npiggin@gmail.com

KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races

2021-06-10T12:12:13+00:00

irq_work's use of the DEC SPR is racy with guest<->host switch and guest entry which flips the DEC interrupt to guest, which could lose a host work interrupt. This patch closes one race, and attempts to comment another class of races. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210528090752.3542186-11-npiggin@gmail.com

powerpc/time: move timer_broadcast_interrupt prototype to asm/time.h

2021-02-08T13:02:10+00:00

Interrupt handler prototypes are going to be rearranged in a future patch, so tidy this out of the way first. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210130130852.2952424-21-npiggin@gmail.com

powerpc/time: Remove ifdef in get_vtb()

2020-12-03T14:01:32+00:00

SPRN_VTB and CPU_FTR_ARCH_207S are always defined, no need of an ifdef. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a0fc81cd85121407726bcf480fc9a0d8e7617fce.1601549933.git.christophe.leroy@csgroup.eu

powerpc/time: Move timebase functions into new asm/vdso/timebase.h

2020-12-03T14:01:10+00:00

In order to easily use get_tb() from C VDSO, move timebase functions into a new header named asm/vdso/timebase.h Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-3-mpe@ellerman.id.au