1 /*- 2 * Copyright (c) 2017 Hans Petter Selasky 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <linux/kthread.h> 31 #include <linux/sched.h> 32 #include <linux/compat.h> 33 34 #include <sys/bus.h> 35 #include <sys/interrupt.h> 36 #include <sys/priority.h> 37 38 enum { 39 KTHREAD_SHOULD_STOP_MASK = (1 << 0), 40 KTHREAD_SHOULD_PARK_MASK = (1 << 1), 41 KTHREAD_IS_PARKED_MASK = (1 << 2), 42 }; 43 44 bool 45 kthread_should_stop_task(struct task_struct *task) 46 { 47 48 return (atomic_read(&task->kthread_flags) & KTHREAD_SHOULD_STOP_MASK); 49 } 50 51 bool 52 kthread_should_stop(void) 53 { 54 55 return (atomic_read(¤t->kthread_flags) & KTHREAD_SHOULD_STOP_MASK); 56 } 57 58 int 59 kthread_stop(struct task_struct *task) 60 { 61 int retval; 62 63 /* 64 * Assume task is still alive else caller should not call 65 * kthread_stop(): 66 */ 67 atomic_or(KTHREAD_SHOULD_STOP_MASK, &task->kthread_flags); 68 wake_up_process(task); 69 wait_for_completion(&task->exited); 70 71 /* 72 * Get return code and free task structure: 73 */ 74 retval = task->task_ret; 75 put_task_struct(task); 76 77 return (retval); 78 } 79 80 struct task_struct * 81 linux_kthread_setup_and_run(struct thread *td, linux_task_fn_t *task_fn, void *arg) 82 { 83 struct task_struct *task; 84 85 linux_set_current(td); 86 87 task = td->td_lkpi_task; 88 task->task_fn = task_fn; 89 task->task_data = arg; 90 91 thread_lock(td); 92 /* make sure the scheduler priority is raised */ 93 sched_prio(td, PI_SWI(SWI_NET)); 94 /* put thread into run-queue */ 95 sched_add(td, SRQ_BORING); 96 thread_unlock(td); 97 98 return (task); 99 } 100 101 void 102 linux_kthread_fn(void *arg __unused) 103 { 104 struct task_struct *task = current; 105 106 if (kthread_should_stop_task(task) == 0) 107 task->task_ret = task->task_fn(task->task_data); 108 109 if (kthread_should_stop_task(task) != 0) { 110 struct thread *td = curthread; 111 112 /* let kthread_stop() free data */ 113 td->td_lkpi_task = NULL; 114 115 /* wakeup kthread_stop() */ 116 complete(&task->exited); 117 } 118 kthread_exit(); 119 } 120 121