From 85cde0192a983b227341be11af2c3625d39bc374 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Tue, 13 Oct 2020 22:35:27 +0200 Subject: s390/udelay: make it work for the early code Currently udelay relies on working EXT interrupts handler, which is not the case during early startup. In such cases udelay_simple() has to be used instead. To avoid mistakes of calling udelay too early, which could happen from the common code as well - make udelay work for the early code by introducing static branch and redirecting all udelay calls to udelay_simple until EXT interrupts handler is fully initialized and async stack is allocated. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens --- arch/s390/lib/delay.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'arch/s390/lib/delay.c') diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index daca7bad66de..1734a5c19834 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()) { -- cgit v1.2.3