diff --git a/arch/s390/include/asm/delay.h b/arch/s390/include/asm/delay.h index 898323fd93d2b9b0885bda17cd097ab6dfef20dc..4a08379cd1eb75067b729fd68a91932a1cebc7b1 100644 --- a/arch/s390/include/asm/delay.h +++ b/arch/s390/include/asm/delay.h @@ -13,6 +13,7 @@ #ifndef _S390_DELAY_H #define _S390_DELAY_H +void udelay_enable(void); void __ndelay(unsigned long long nsecs); void __udelay(unsigned long long usecs); void udelay_simple(unsigned long long usecs); diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 4d843e64496f4d582b50737d6e00d950b39ec42d..2076415aee4b667f5e8a38b04d9914a1290830e7 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -336,6 +336,7 @@ int __init arch_early_irq_init(void) if (!stack) panic("Couldn't allocate async stack"); S390_lowcore.async_stack = stack + STACK_INIT_OFFSET; + udelay_enable(); return 0; } diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index daca7bad66de3e6a5ca68d3a14f3270069e3ecf9..1734a5c19834f858d48e91c49cee0e8957ef3727 100644 --- a/arch/s390/lib/delay.c +++ b/arch/s390/lib/delay.c @@ -13,11 +13,19 @@ #include #include #include +#include #include #include #include #include +static DEFINE_STATIC_KEY_FALSE(udelay_ready); + +void __init udelay_enable(void) +{ + static_branch_enable(&udelay_ready); +} + void __delay(unsigned long loops) { /* @@ -77,6 +85,11 @@ void __udelay(unsigned long long usecs) { unsigned long flags; + if (!static_branch_likely(&udelay_ready)) { + udelay_simple(usecs); + return; + } + preempt_disable(); local_irq_save(flags); if (in_irq()) {