1 /* 2 * Copyright (c) 2017 François Tigeot 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 #ifndef _LINUX_INTERRUPT_H_ 28 #define _LINUX_INTERRUPT_H_ 29 30 #include <linux/kernel.h> 31 #include <linux/bitops.h> 32 #include <linux/irqflags.h> 33 #include <linux/hardirq.h> 34 #include <linux/hrtimer.h> 35 #include <linux/kref.h> 36 37 #include <linux/atomic.h> 38 39 struct tasklet_struct { 40 unsigned long state; 41 void (*func)(unsigned long); 42 unsigned long data; 43 struct lock lock; 44 }; 45 46 enum { 47 TASKLET_STATE_SCHED, 48 TASKLET_STATE_RUN 49 }; 50 51 /* 52 * TODO: verify these points: 53 * - tasklets that have the same type cannot be run on multiple processors at the same time 54 * - tasklets always run on the processor from which they were originally 55 * submitted 56 * - when a tasklet is scheduled, its state is set to TASKLET_STATE_SCHED, and the tasklet 57 * added to a queue 58 * - during the execution of its function, the tasklet state is set to TASKLET_STATE_RUN 59 * and the TASKLET_STATE_SCHED state is removed 60 */ 61 62 /* XXX scheduling and execution should be handled separately */ 63 static inline void 64 tasklet_schedule(struct tasklet_struct *t) 65 { 66 set_bit(TASKLET_STATE_SCHED, &t->state); 67 68 lockmgr(&t->lock, LK_EXCLUSIVE); 69 clear_bit(TASKLET_STATE_SCHED, &t->state); 70 71 set_bit(TASKLET_STATE_RUN, &t->state); 72 if (t->func) 73 t->func(t->data); 74 clear_bit(TASKLET_STATE_RUN, &t->state); 75 76 lockmgr(&t->lock, LK_RELEASE); 77 } 78 79 /* This function ensures that the tasklet is not scheduled to run again */ 80 /* XXX this doesn't kill anything */ 81 static inline void 82 tasklet_kill(struct tasklet_struct *t) 83 { 84 lockmgr(&t->lock, LK_EXCLUSIVE); 85 clear_bit(TASKLET_STATE_SCHED, &t->state); 86 lockmgr(&t->lock, LK_RELEASE); 87 } 88 89 static inline void 90 tasklet_init(struct tasklet_struct *t, void (*func)(unsigned long), unsigned long data) 91 { 92 lockinit(&t->lock, "ltasklet", 0, LK_CANRECURSE); 93 t->state = 0; 94 t->func = func; 95 t->data = data; 96 } 97 98 #endif /* _LINUX_INTERRUPT_H_ */ 99