From: Bibo Mao maobibo@loongson.cn

LoongArch inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8H1QC

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1. When cpu is hotplug out, cpu is in idle state and function arch_cpu_idle_dead is called. Timer interrupt for this processor should be disabled, else there will be timer interrupt for the dead cpu. Also this prevents vcpu to schedule out during halt-polling flow when system is running in vm mode, since there is pending timer interrupt.

This patch adds detailed implementation for timer shutdown interface, so that timer will be disabled when cpu is plug-out.

2. for woken-up cpu, entry address is 8 bytes, we should check first low 4 bytes and then high 4 bytes.

Signed-off-by: Bibo Mao maobibo@loongson.cn Signed-off-by: Hongchen Zhang zhanghongchen@loongson.cn --- arch/loongarch/kernel/smp.c | 17 +++++++++++++++-- arch/loongarch/kernel/time.c | 25 +++++++++---------------- 2 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index f5a94559d441..abf6484fac70 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -310,16 +310,29 @@ void play_dead(void) register void (*init_fn)(void);

idle_task_exit(); - local_irq_enable(); + /* + * vcpu can be woken up from idle emulation in vm if irq is disabled + */ + if (!cpu_has_hypervisor) + local_irq_enable(); set_csr_ecfg(ECFGF_IPI); __this_cpu_write(cpu_state, CPU_DEAD);

__smp_mb(); do { __asm__ __volatile__("idle 0\n\t"); - addr = iocsr_read64(LOONGARCH_IOCSR_MBUF0); + /* + * mailbox info is wroten from other CPU with IPI send method + * in function csr_mail_send, only 4 bytes can be wroten with + * IPI send method in one time. + * + * High 4 bytes is sent and then low 4 bytes for 8 bytes mail + * sending method. Here low 4 bytes is read by the first. + */ + addr = iocsr_read32(LOONGARCH_IOCSR_MBUF0); } while (addr == 0);

+ addr = iocsr_read64(LOONGARCH_IOCSR_MBUF0); init_fn = (void *)TO_CACHE(addr); iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_CLEAR);

diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c index 18fa38705da7..b2e8108bee10 100644 --- a/arch/loongarch/kernel/time.c +++ b/arch/loongarch/kernel/time.c @@ -59,21 +59,6 @@ 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) -{ - unsigned long timer_config; - - raw_spin_lock(&state_lock); - - timer_config = csr_read64(LOONGARCH_CSR_TCFG); - timer_config &= ~CSR_TCFG_EN; - csr_write64(timer_config, LOONGARCH_CSR_TCFG); - - raw_spin_unlock(&state_lock); - - return 0; -} - static int constant_set_state_periodic(struct clock_event_device *evt) { unsigned long period; @@ -93,6 +78,14 @@ static int constant_set_state_periodic(struct clock_event_device *evt)

static int constant_set_state_shutdown(struct clock_event_device *evt) { + unsigned long timer_config; + + raw_spin_lock(&state_lock); + timer_config = csr_read64(LOONGARCH_CSR_TCFG); + timer_config &= ~CSR_TCFG_EN; + csr_write64(timer_config, LOONGARCH_CSR_TCFG); + raw_spin_unlock(&state_lock); + return 0; }

@@ -161,7 +154,7 @@ 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;