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| author |   Heiko Carstens <hca@linux.ibm.com> | 2020-11-16 08:06:41 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-23 12:01:13 +0100 |
| commit | 80f06306240e0ad1c75116111be11950474dfda7 (patch) | |
| tree | 99ed304a1c6d26ad408145ba98b83d9fbf807b7f /arch/s390/include/asm/timex.h | |
| parent | s390/mm: add debug user asce support (diff) | |
| download | linux-dev-80f06306240e0ad1c75116111be11950474dfda7.tar.xz linux-dev-80f06306240e0ad1c75116111be11950474dfda7.zip | |
s390/vdso: reimplement getcpu vdso syscall
Implement the previously removed getcpu vdso syscall by using the
TOD programmable field to pass the cpu number to user space.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/timex.h')
| -rw-r--r-- | arch/s390/include/asm/timex.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index 289aaff4d365..c8e244ecdfde 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -49,6 +49,13 @@ static inline void set_clock_comparator(__u64 time) asm volatile("sckc %0" : : "Q" (time)); } +static inline void set_tod_programmable_field(u16 val) +{ + register unsigned long reg0 asm("0") = val; + + asm volatile("sckpf" : : "d" (reg0)); +} + void clock_comparator_work(void); void __init time_early_init(void); |