| Niranjan Yadla | 19336af | 2018-04-19 12:19:27 -0700 | [diff] [blame] | 1 | /******************************************************************************* |
| 2 | * Copyright (C) 2018 Cadence Design Systems, Inc. |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files (the |
| 6 | * "Software"), to use this Software with Cadence processor cores only and |
| 7 | * not with any other processors and platforms, subject to |
| 8 | * the following conditions: |
| 9 | * |
| 10 | * The above copyright notice and this permission notice shall be included |
| 11 | * in all copies or substantial portions of the Software. |
| 12 | * |
| 13 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 14 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 15 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 16 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 17 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 18 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 19 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 20 | |
| 21 | ******************************************************************************/ |
| 22 | |
| 23 | /******************************************************************************* |
| 24 | * xf-sched.h |
| 25 | * |
| 26 | * Non-preemptive earliest-deadline-first scheduler |
| 27 | * |
| 28 | ******************************************************************************/ |
| 29 | |
| 30 | #ifndef __XF_SCHED_H |
| 31 | #define __XF_SCHED_H |
| 32 | |
| 33 | /******************************************************************************* |
| 34 | * Types definitions |
| 35 | ******************************************************************************/ |
| 36 | |
| 37 | /* ...scheduler data */ |
| 38 | typedef rb_tree_t xf_sched_t; |
| 39 | |
| 40 | /* ...scheduling item */ |
| 41 | typedef rb_node_t xf_task_t; |
| 42 | |
| 43 | /******************************************************************************* |
| 44 | * Helpers |
| 45 | ******************************************************************************/ |
| 46 | |
| 47 | /* ...retrieve timestamp from task handle */ |
| 48 | static inline u32 xf_task_timestamp(xf_task_t *t) |
| 49 | { |
| 50 | /* ...wipe out last bit of "color" */ |
| 51 | return (((rb_node_t *)t)->color & ~1); |
| 52 | } |
| 53 | |
| 54 | /* ...set task decoding timestamp */ |
| 55 | static inline u32 xf_task_timestamp_set(xf_task_t *t, u32 ts) |
| 56 | { |
| 57 | /* ...technically, wiping out last bit of timestamp is not needed */ |
| 58 | return (((rb_node_t *)t)->color = ts); |
| 59 | } |
| 60 | |
| 61 | /* ...compare two timestamps with respect to wrap-around */ |
| 62 | static inline int xf_timestamp_before(u32 t0, u32 t1) |
| 63 | { |
| 64 | /* ...distance between active items is never high */ |
| 65 | return ((s32)(t0 - t1) < 0); |
| 66 | } |
| 67 | |
| 68 | /* ...current scheduler timestamp */ |
| 69 | static inline u32 xf_sched_timestamp(xf_sched_t *sched) |
| 70 | { |
| 71 | /* ...don't quite care about last bit */ |
| 72 | return ((rb_tree_t *)sched)->root.color; |
| 73 | } |
| 74 | |
| 75 | /* ...set scheduler timestamp */ |
| 76 | static inline u32 xf_sched_timestamp_set(xf_sched_t *sched, u32 ts) |
| 77 | { |
| 78 | /* ...wipe out last bit (black color is 0) */ |
| 79 | return (((rb_tree_t *)sched)->root.color = ts & ~0x1); |
| 80 | } |
| 81 | |
| 82 | /******************************************************************************* |
| 83 | * Entry points |
| 84 | ******************************************************************************/ |
| 85 | |
| 86 | /* ...place message into scheduler queue */ |
| 87 | extern void xf_sched_put(xf_sched_t *sched, xf_task_t *t, u32 ts); |
| 88 | |
| 89 | /* ...get first item from the scheduler */ |
| 90 | extern xf_task_t * xf_sched_get(xf_sched_t *sched); |
| 91 | |
| 92 | /* ...cancel task execution */ |
| 93 | extern void xf_sched_cancel(xf_sched_t *sched, xf_task_t *t); |
| 94 | |
| 95 | /* ...initialize scheduler */ |
| 96 | extern void xf_sched_init(xf_sched_t *sched); |
| 97 | |
| 98 | #endif /* __XF_SCHED_H */ |