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