6.1-stable review patch. If anyone has any objections, please let me know.
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From: Bibo Mao maobibo@loongson.cn
[ Upstream commit d43f37b73468c172bc89ac4824a1511b411f0778 ]
When a cpu is hot-unplugged, it is put in idle state and the function arch_cpu_idle_dead() is called. The timer interrupt for this processor should be disabled, otherwise there will be pending timer interrupt for the unplugged cpu, so that vcpu is prevented from giving up scheduling when system is running in vm mode.
This patch implements the timer shutdown interface so that the constant timer will be properly disabled when a CPU is hot-unplugged.
Reviewed-by: WANG Xuerui git@xen0n.name Signed-off-by: Bibo Mao maobibo@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Sasha Levin sashal@kernel.org --- arch/loongarch/kernel/time.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-)
diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c index d2b7d5df132a9..150df6e17bb6a 100644 --- a/arch/loongarch/kernel/time.c +++ b/arch/loongarch/kernel/time.c @@ -58,14 +58,16 @@ static int constant_set_state_oneshot(struct clock_event_device *evt) return 0; }
-static int constant_set_state_oneshot_stopped(struct clock_event_device *evt) +static int constant_set_state_periodic(struct clock_event_device *evt) { + unsigned long period; unsigned long timer_config;
raw_spin_lock(&state_lock);
- timer_config = csr_read64(LOONGARCH_CSR_TCFG); - timer_config &= ~CSR_TCFG_EN; + period = const_clock_freq / HZ; + timer_config = period & CSR_TCFG_VAL; + timer_config |= (CSR_TCFG_PERIOD | CSR_TCFG_EN); csr_write64(timer_config, LOONGARCH_CSR_TCFG);
raw_spin_unlock(&state_lock); @@ -73,16 +75,14 @@ static int constant_set_state_oneshot_stopped(struct clock_event_device *evt) return 0; }
-static int constant_set_state_periodic(struct clock_event_device *evt) +static int constant_set_state_shutdown(struct clock_event_device *evt) { - unsigned long period; unsigned long timer_config;
raw_spin_lock(&state_lock);
- period = const_clock_freq / HZ; - timer_config = period & CSR_TCFG_VAL; - timer_config |= (CSR_TCFG_PERIOD | CSR_TCFG_EN); + timer_config = csr_read64(LOONGARCH_CSR_TCFG); + timer_config &= ~CSR_TCFG_EN; csr_write64(timer_config, LOONGARCH_CSR_TCFG);
raw_spin_unlock(&state_lock); @@ -90,11 +90,6 @@ static int constant_set_state_periodic(struct clock_event_device *evt) return 0; }
-static int constant_set_state_shutdown(struct clock_event_device *evt) -{ - return 0; -} - static int constant_timer_next_event(unsigned long delta, struct clock_event_device *evt) { unsigned long timer_config; @@ -156,7 +151,7 @@ int constant_clockevent_init(void) cd->rating = 320; cd->cpumask = cpumask_of(cpu); cd->set_state_oneshot = constant_set_state_oneshot; - cd->set_state_oneshot_stopped = constant_set_state_oneshot_stopped; + cd->set_state_oneshot_stopped = constant_set_state_shutdown; cd->set_state_periodic = constant_set_state_periodic; cd->set_state_shutdown = constant_set_state_shutdown; cd->set_next_event = constant_timer_next_event;