| /******************************************************************************* |
| * Copyright (C) 2018 Cadence Design Systems, Inc. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files (the |
| * "Software"), to use this Software with Cadence processor cores only and |
| * not with any other processors and platforms, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included |
| * in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| |
| ******************************************************************************/ |
| |
| /******************************************************************************* |
| * xf-sched.h |
| * |
| * Non-preemptive earliest-deadline-first scheduler |
| * |
| ******************************************************************************/ |
| |
| #ifndef __XF_SCHED_H |
| #define __XF_SCHED_H |
| |
| /******************************************************************************* |
| * Types definitions |
| ******************************************************************************/ |
| |
| /* ...scheduler data */ |
| typedef rb_tree_t xf_sched_t; |
| |
| /* ...scheduling item */ |
| typedef rb_node_t xf_task_t; |
| |
| /******************************************************************************* |
| * Helpers |
| ******************************************************************************/ |
| |
| /* ...retrieve timestamp from task handle */ |
| static inline u32 xf_task_timestamp(xf_task_t *t) |
| { |
| /* ...wipe out last bit of "color" */ |
| return (((rb_node_t *)t)->color & ~1); |
| } |
| |
| /* ...set task decoding timestamp */ |
| static inline u32 xf_task_timestamp_set(xf_task_t *t, u32 ts) |
| { |
| /* ...technically, wiping out last bit of timestamp is not needed */ |
| return (((rb_node_t *)t)->color = ts); |
| } |
| |
| /* ...compare two timestamps with respect to wrap-around */ |
| static inline int xf_timestamp_before(u32 t0, u32 t1) |
| { |
| /* ...distance between active items is never high */ |
| return ((s32)(t0 - t1) < 0); |
| } |
| |
| /* ...current scheduler timestamp */ |
| static inline u32 xf_sched_timestamp(xf_sched_t *sched) |
| { |
| /* ...don't quite care about last bit */ |
| return ((rb_tree_t *)sched)->root.color; |
| } |
| |
| /* ...set scheduler timestamp */ |
| static inline u32 xf_sched_timestamp_set(xf_sched_t *sched, u32 ts) |
| { |
| /* ...wipe out last bit (black color is 0) */ |
| return (((rb_tree_t *)sched)->root.color = ts & ~0x1); |
| } |
| |
| /******************************************************************************* |
| * Entry points |
| ******************************************************************************/ |
| |
| /* ...place message into scheduler queue */ |
| extern void xf_sched_put(xf_sched_t *sched, xf_task_t *t, u32 ts); |
| |
| /* ...get first item from the scheduler */ |
| extern xf_task_t * xf_sched_get(xf_sched_t *sched); |
| |
| /* ...cancel task execution */ |
| extern void xf_sched_cancel(xf_sched_t *sched, xf_task_t *t); |
| |
| /* ...initialize scheduler */ |
| extern void xf_sched_init(xf_sched_t *sched); |
| |
| #endif /* __XF_SCHED_H */ |