From 1efdd4bd254311498123a15fa0acd565f454da97 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sat, 1 Dec 2018 11:53:10 +1100 Subject: m68k: Call timer_interrupt() with interrupts disabled Some platforms execute their timer handler with the interrupt priority level set below 6. That means the handler could be interrupted by another driver and this could lead to re-entry of the timer core. Avoid this by use of local_irq_save/restore for timer interrupt dispatch. This provides mutual exclusion around the timer interrupt flag access which is needed later in this series for the clocksource conversion. Reported-by: Thomas Gleixner Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1811131407120.2697@nanos.tec.linutronix.de Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven --- arch/m68k/atari/ataints.c | 4 ++-- arch/m68k/atari/time.c | 15 ++++++++++++++- 2 files changed, 16 insertions(+), 3 deletions(-) (limited to 'arch/m68k/atari') diff --git a/arch/m68k/atari/ataints.c b/arch/m68k/atari/ataints.c index 3d2b63bedf05..56f02ea2c248 100644 --- a/arch/m68k/atari/ataints.c +++ b/arch/m68k/atari/ataints.c @@ -142,7 +142,7 @@ struct mfptimerbase { .name = "MFP Timer D" }; -static irqreturn_t mfptimer_handler(int irq, void *dev_id) +static irqreturn_t mfp_timer_d_handler(int irq, void *dev_id) { struct mfptimerbase *base = dev_id; int mach_irq; @@ -344,7 +344,7 @@ void __init atari_init_IRQ(void) st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6; /* request timer D dispatch handler */ - if (request_irq(IRQ_MFP_TIMD, mfptimer_handler, IRQF_SHARED, + if (request_irq(IRQ_MFP_TIMD, mfp_timer_d_handler, IRQF_SHARED, stmfp_base.name, &stmfp_base)) pr_err("Couldn't register %s interrupt\n", stmfp_base.name); diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c index 9cca64286464..fafa20f75ab9 100644 --- a/arch/m68k/atari/time.c +++ b/arch/m68k/atari/time.c @@ -24,6 +24,18 @@ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL_GPL(rtc_lock); +static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id) +{ + irq_handler_t timer_routine = dev_id; + unsigned long flags; + + local_irq_save(flags); + timer_routine(0, NULL); + local_irq_restore(flags); + + return IRQ_HANDLED; +} + void __init atari_sched_init(irq_handler_t timer_routine) { @@ -32,7 +44,8 @@ atari_sched_init(irq_handler_t timer_routine) /* start timer C, div = 1:100 */ st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; /* install interrupt service routine for MFP Timer C */ - if (request_irq(IRQ_MFP_TIMC, timer_routine, 0, "timer", timer_routine)) + if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, 0, "timer", + timer_routine)) pr_err("Couldn't register timer interrupt\n"); } -- cgit v1.2.3