diff options
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 66 |
1 files changed, 65 insertions, 1 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index a53af6fe81a6..1d5cba142828 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -25,6 +25,7 @@ #include <linux/cpu.h> #include <linux/sched/isolation.h> #include <linux/sched/task_stack.h> +#include <linux/smpboot.h> #include <linux/delay.h> #include <linux/panic_notifier.h> @@ -1350,7 +1351,7 @@ static void vmbus_message_sched(struct hv_per_cpu_context *hv_cpu, void *message } } -void vmbus_isr(void) +static void __vmbus_isr(void) { struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context); @@ -1363,6 +1364,53 @@ void vmbus_isr(void) add_interrupt_randomness(vmbus_interrupt); } + +static DEFINE_PER_CPU(bool, vmbus_irq_pending); +static DEFINE_PER_CPU(struct task_struct *, vmbus_irqd); + +static void vmbus_irqd_wake(void) +{ + struct task_struct *tsk = __this_cpu_read(vmbus_irqd); + + __this_cpu_write(vmbus_irq_pending, true); + wake_up_process(tsk); +} + +static void vmbus_irqd_setup(unsigned int cpu) +{ + sched_set_fifo(current); +} + +static int vmbus_irqd_should_run(unsigned int cpu) +{ + return __this_cpu_read(vmbus_irq_pending); +} + +static void run_vmbus_irqd(unsigned int cpu) +{ + __this_cpu_write(vmbus_irq_pending, false); + __vmbus_isr(); +} + +static bool vmbus_irq_initialized; + +static struct smp_hotplug_thread vmbus_irq_threads = { + .store = &vmbus_irqd, + .setup = vmbus_irqd_setup, + .thread_should_run = vmbus_irqd_should_run, + .thread_fn = run_vmbus_irqd, + .thread_comm = "vmbus_irq/%u", +}; + +void vmbus_isr(void) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + vmbus_irqd_wake(); + } else { + lockdep_hardirq_threaded(); + __vmbus_isr(); + } +} EXPORT_SYMBOL_FOR_MODULES(vmbus_isr, "mshv_vtl"); static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) @@ -1462,6 +1510,13 @@ static int vmbus_bus_init(void) * the VMbus interrupt handler. */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && !vmbus_irq_initialized) { + ret = smpboot_register_percpu_thread(&vmbus_irq_threads); + if (ret) + goto err_kthread; + vmbus_irq_initialized = true; + } + if (vmbus_irq == -1) { hv_setup_vmbus_handler(vmbus_isr); } else { @@ -1507,6 +1562,11 @@ err_connect: free_percpu(vmbus_evt); } err_setup: + if (IS_ENABLED(CONFIG_PREEMPT_RT) && vmbus_irq_initialized) { + smpboot_unregister_percpu_thread(&vmbus_irq_threads); + vmbus_irq_initialized = false; + } +err_kthread: bus_unregister(&hv_bus); return ret; } @@ -2976,6 +3036,10 @@ static void __exit vmbus_exit(void) free_percpu_irq(vmbus_irq, vmbus_evt); free_percpu(vmbus_evt); } + if (IS_ENABLED(CONFIG_PREEMPT_RT) && vmbus_irq_initialized) { + smpboot_unregister_percpu_thread(&vmbus_irq_threads); + vmbus_irq_initialized = false; + } for_each_online_cpu(cpu) { struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); |