[PATCH 6/9] s390/irq/idle: Remove psw bits early
From: Heiko Carstens
Date: Wed Feb 18 2026 - 09:21:37 EST
Remove wait, io, external interrupt bits early in do_io_irq()/do_ext_irq()
when previous context was idle. This saves one conditional branch and is
closer to the original old assembly code.
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
---
arch/s390/kernel/irq.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 080e9285b337..084919a04e04 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -147,8 +147,10 @@ void noinstr do_io_irq(struct pt_regs *regs)
bool from_idle;
from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
- if (from_idle)
+ if (from_idle) {
update_timer_idle();
+ regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
+ }
irq_enter_rcu();
@@ -174,9 +176,6 @@ void noinstr do_io_irq(struct pt_regs *regs)
set_irq_regs(old_regs);
irqentry_exit(regs, state);
-
- if (from_idle)
- regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
}
void noinstr do_ext_irq(struct pt_regs *regs)
@@ -186,8 +185,10 @@ void noinstr do_ext_irq(struct pt_regs *regs)
bool from_idle;
from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
- if (from_idle)
+ if (from_idle) {
update_timer_idle();
+ regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
+ }
irq_enter_rcu();
@@ -209,9 +210,6 @@ void noinstr do_ext_irq(struct pt_regs *regs)
irq_exit_rcu();
set_irq_regs(old_regs);
irqentry_exit(regs, state);
-
- if (from_idle)
- regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
}
static void show_msi_interrupt(struct seq_file *p, int irq)
--
2.51.0