From: Peter Zijlstra Date: Fri, 19 May 2023 10:21:03 +0000 (+0200) Subject: loongarch: Provide noinstr sched_clock_read() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6b10fef09f937433563822f4bb6a2f947176e5a0;p=linux.git loongarch: Provide noinstr sched_clock_read() 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_read() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. Signed-off-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley # Hyper-V Link: https://lore.kernel.org/r/20230519102715.502547082@infradead.org --- diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h index b3323ab5b78d3..357ef701e7d7e 100644 --- a/arch/loongarch/include/asm/loongarch.h +++ b/arch/loongarch/include/asm/loongarch.h @@ -1167,7 +1167,7 @@ static __always_inline void iocsr_write64(u64 val, u32 reg) #ifndef __ASSEMBLY__ -static inline u64 drdtime(void) +static __always_inline u64 drdtime(void) { int rID = 0; u64 val = 0; diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c index f377e50f3c66c..c189e03cd5da8 100644 --- a/arch/loongarch/kernel/time.c +++ b/arch/loongarch/kernel/time.c @@ -190,9 +190,9 @@ static u64 read_const_counter(struct clocksource *clk) return drdtime(); } -static u64 native_sched_clock(void) +static noinstr u64 sched_clock_read(void) { - return read_const_counter(NULL); + return drdtime(); } static struct clocksource clocksource_const = { @@ -211,7 +211,7 @@ int __init constant_clocksource_init(void) res = clocksource_register_hz(&clocksource_const, freq); - sched_clock_register(native_sched_clock, 64, freq); + sched_clock_register(sched_clock_read, 64, freq); pr_info("Constant clock source device register\n");