diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2023-05-19 12:21:04 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-06-05 21:11:06 +0200 |
| commit | 91b41a237512b569746e1f560a42d9fba077261d (patch) | |
| tree | 03db4aa84444888fb7d7d731fe61575fe58b47e3 | |
| parent | 6b10fef09f937433563822f4bb6a2f947176e5a0 (diff) | |
s390/time: Provide sched_clock_noinstr()
With the intent to provide local_clock_noinstr(), a variant of
local_clock() that's safe to be called from noinstr code (with the
assumption that any such code will already be non-preemptible),
prepare for things by providing a noinstr sched_clock_noinstr()
function.
Specifically, preempt_enable_*() calls out to schedule(), which upsets
noinstr validation efforts.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.570170436@infradead.org
| -rw-r--r-- | arch/s390/include/asm/timex.h | 13 | ||||
| -rw-r--r-- | arch/s390/kernel/time.c | 5 |
2 files changed, 14 insertions, 4 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index ce878e85b6e4..4d646659a5f5 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -63,7 +63,7 @@ static inline int store_tod_clock_ext_cc(union tod_clock *clk) return cc; } -static inline void store_tod_clock_ext(union tod_clock *tod) +static __always_inline void store_tod_clock_ext(union tod_clock *tod) { asm volatile("stcke %0" : "=Q" (*tod) : : "cc"); } @@ -177,7 +177,7 @@ static inline void local_tick_enable(unsigned long comp) typedef unsigned long cycles_t; -static inline unsigned long get_tod_clock(void) +static __always_inline unsigned long get_tod_clock(void) { union tod_clock clk; @@ -204,6 +204,11 @@ void init_cpu_timer(void); extern union tod_clock tod_clock_base; +static __always_inline unsigned long __get_tod_clock_monotonic(void) +{ + return get_tod_clock() - tod_clock_base.tod; +} + /** * get_clock_monotonic - returns current time in clock rate units * @@ -216,7 +221,7 @@ static inline unsigned long get_tod_clock_monotonic(void) unsigned long tod; preempt_disable_notrace(); - tod = get_tod_clock() - tod_clock_base.tod; + tod = __get_tod_clock_monotonic(); preempt_enable_notrace(); return tod; } @@ -240,7 +245,7 @@ static inline unsigned long get_tod_clock_monotonic(void) * -> ns = (th * 125) + ((tl * 125) >> 9); * */ -static inline unsigned long tod_to_ns(unsigned long todval) +static __always_inline unsigned long tod_to_ns(unsigned long todval) { return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9); } diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 6b7b6d5e3632..276278199c44 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -102,6 +102,11 @@ void __init time_early_init(void) ((long) qui.old_leap * 4096000000L); } +unsigned long long noinstr sched_clock_noinstr(void) +{ + return tod_to_ns(__get_tod_clock_monotonic()); +} + /* * Scheduler clock - returns current time in nanosec units. */ |