rt_Task.c

00001 /**
00002  * @file    rt_Task.c
00003  * @brief   
00004  *
00005  * DAPLink Interface Firmware
00006  * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
00007  * SPDX-License-Identifier: Apache-2.0
00008  *
00009  * Licensed under the Apache License, Version 2.0 (the "License"); you may
00010  * not use this file except in compliance with the License.
00011  * You may obtain a copy of the License at
00012  *
00013  * http://www.apache.org/licenses/LICENSE-2.0
00014  *
00015  * Unless required by applicable law or agreed to in writing, software
00016  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00017  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00018  * See the License for the specific language governing permissions and
00019  * limitations under the License.
00020  */
00021 
00022 #include "rt_TypeDef.h"
00023 #include "RTX_Config.h"
00024 #include "rt_System.h"
00025 #include "rt_Task.h"
00026 #include "rt_List.h"
00027 #include "rt_MemBox.h"
00028 #include "rt_Robin.h"
00029 #include "rt_HAL_CM.h"
00030 
00031 /*----------------------------------------------------------------------------
00032  *      Global Variables
00033  *---------------------------------------------------------------------------*/
00034 
00035 /* Running and next task info. */
00036 struct OS_TSK os_tsk;
00037 
00038 /* Task Control Blocks of idle demon */
00039 struct OS_TCB os_idle_TCB;
00040 
00041 
00042 /*----------------------------------------------------------------------------
00043  *      Local Functions
00044  *---------------------------------------------------------------------------*/
00045 
00046 static OS_TID rt_get_TID (void) {
00047   U32 tid;
00048 
00049   for (tid = 1; tid <= os_maxtaskrun; tid++) {
00050     if (os_active_TCB[tid-1] == NULL) {
00051       return ((OS_TID)tid);
00052     }
00053   }
00054   return (0);
00055 }
00056 
00057 
00058 /*--------------------------- rt_init_context -------------------------------*/
00059 
00060 static void rt_init_context (P_TCB p_TCB, U8 priority, FUNCP task_body) {
00061   /* Initialize general part of the Task Control Block. */
00062   p_TCB->cb_type = TCB;
00063   p_TCB->state   = READY;
00064   p_TCB->prio    = priority;
00065   p_TCB->p_lnk   = NULL;
00066   p_TCB->p_rlnk  = NULL;
00067   p_TCB->p_dlnk  = NULL;
00068   p_TCB->p_blnk  = NULL;
00069   p_TCB->delta_time    = 0;
00070   p_TCB->interval_time = 0;
00071   p_TCB->events  = 0;
00072   p_TCB->waits   = 0;
00073   p_TCB->ret_val = OS_R_OK;
00074   p_TCB->ret_upd = 0;
00075 
00076   if (p_TCB->priv_stack == 0) {
00077     /* Allocate the memory space for the stack. */
00078     p_TCB->stack = rt_alloc_box (mp_stk);
00079   }
00080   rt_init_stack (p_TCB, task_body);
00081 }
00082 
00083 
00084 /*--------------------------- rt_switch_req ---------------------------------*/
00085 
00086 void rt_switch_req (P_TCB p_new) {
00087   /* Switch to next task (identified by "p_new"). */
00088   os_tsk.new   = p_new;
00089   p_new->state = RUNNING;
00090   DBG_TASK_SWITCH(p_new->task_id);
00091 }
00092 
00093 
00094 /*--------------------------- rt_dispatch -----------------------------------*/
00095 
00096 void rt_dispatch (P_TCB next_TCB) {
00097   /* Dispatch next task if any identified or dispatch highest ready task    */
00098   /* "next_TCB" identifies a task to run or has value NULL (=no next task)  */
00099   if (next_TCB == NULL) {
00100     /* Running task was blocked: continue with highest ready task */
00101     next_TCB = rt_get_first (&os_rdy);
00102     rt_switch_req (next_TCB);
00103   }
00104   else {
00105     /* Check which task continues */
00106     if (next_TCB->prio > os_tsk.run->prio) {
00107       /* preempt running task */
00108       rt_put_rdy_first (os_tsk.run);
00109       os_tsk.run->state = READY;
00110       rt_switch_req (next_TCB);
00111     }
00112     else {
00113       /* put next task into ready list, no task switch takes place */
00114       next_TCB->state = READY;
00115       rt_put_prio (&os_rdy, next_TCB);
00116     }
00117   }
00118 }
00119 
00120 
00121 /*--------------------------- rt_block --------------------------------------*/
00122 
00123 void rt_block (U16 timeout, U8 block_state) {
00124   /* Block running task and choose next ready task.                         */
00125   /* "timeout" sets a time-out value or is 0xffff (=no time-out).           */
00126   /* "block_state" defines the appropriate task state */
00127   P_TCB next_TCB;
00128 
00129   if (timeout) {
00130     if (timeout < 0xffff) {
00131       rt_put_dly (os_tsk.run, timeout);
00132     }
00133     os_tsk.run->state = block_state;
00134     next_TCB = rt_get_first (&os_rdy);
00135     rt_switch_req (next_TCB);
00136   }
00137 }
00138 
00139 
00140 /*--------------------------- rt_tsk_pass -----------------------------------*/
00141 
00142 void rt_tsk_pass (void) {
00143   /* Allow tasks of same priority level to run cooperatively.*/
00144   P_TCB p_new;
00145 
00146   p_new = rt_get_same_rdy_prio();
00147   if (p_new != NULL) {
00148     rt_put_prio ((P_XCB)&os_rdy, os_tsk.run);
00149     os_tsk.run->state = READY;
00150     rt_switch_req (p_new);
00151   }
00152 }
00153 
00154 
00155 /*--------------------------- rt_tsk_self -----------------------------------*/
00156 
00157 OS_TID rt_tsk_self (void) {
00158   /* Return own task identifier value. */
00159   if (os_tsk.run == NULL) {
00160     return (0);
00161   }
00162   return (os_tsk.run->task_id);
00163 }
00164 
00165 
00166 /*--------------------------- rt_tsk_prio -----------------------------------*/
00167 
00168 OS_RESULT rt_tsk_prio (OS_TID task_id, U8 new_prio) {
00169   /* Change execution priority of a task to "new_prio". */
00170   P_TCB p_task;
00171 
00172   if (task_id == 0) {
00173     /* Change execution priority of calling task. */
00174     os_tsk.run->prio = new_prio;
00175 run:if (rt_rdy_prio() > new_prio) {
00176       rt_put_prio (&os_rdy, os_tsk.run);
00177       os_tsk.run->state   = READY;
00178       os_tsk.run->ret_val = OS_R_OK;
00179       rt_dispatch (NULL);
00180     }
00181     return (OS_R_OK);
00182   }
00183 
00184   /* Find the task in the "os_active_TCB" array. */
00185   if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
00186     /* Task with "task_id" not found or not started. */
00187     return (OS_R_NOK);
00188   }
00189   p_task = os_active_TCB[task_id-1];
00190   p_task->prio = new_prio;
00191   if (p_task == os_tsk.run) {
00192     goto run;
00193   }
00194   rt_resort_prio (p_task);
00195   if (p_task->state == READY) {
00196     /* Task enqueued in a ready list. */
00197     p_task = rt_get_first (&os_rdy);
00198     os_tsk.run->ret_val = OS_R_OK;
00199     rt_dispatch (p_task);
00200   }
00201   return (OS_R_OK);
00202 }
00203 
00204 
00205 /*--------------------------- rt_tsk_create ---------------------------------*/
00206 
00207 OS_TID rt_tsk_create (FUNCP task, U32 prio_stksz, void *stk, void *argv) {
00208   /* Start a new task declared with "task". */
00209   P_TCB task_context;
00210   U32 i;
00211 
00212   /* Priority 0 is reserved for idle task! */
00213   if ((prio_stksz & 0xFF) == 0) {
00214     prio_stksz += 1;
00215   }
00216   task_context = rt_alloc_box (mp_tcb);
00217   if (task_context == NULL) {
00218     return (0);
00219   }
00220   /* If "size != 0" use a private user provided stack. */
00221   task_context->stack      = stk;
00222   task_context->priv_stack = prio_stksz >> 8;
00223   /* Pass parameter 'argv' to 'rt_init_context' */
00224   task_context->msg = argv;
00225   /* For 'size == 0' system allocates the user stack from the memory pool. */
00226   rt_init_context (task_context, prio_stksz & 0xFF, task);
00227 
00228   /* Find a free entry in 'os_active_TCB' table. */
00229   i = rt_get_TID ();
00230   os_active_TCB[i-1] = task_context;
00231   task_context->task_id = i;
00232   DBG_TASK_NOTIFY(task_context, __TRUE);
00233   rt_dispatch (task_context);
00234   os_tsk.run->ret_val = i;
00235   return ((OS_TID)i);
00236 }
00237 
00238 
00239 /*--------------------------- rt_tsk_delete ---------------------------------*/
00240 
00241 OS_RESULT rt_tsk_delete (OS_TID task_id) {
00242   /* Terminate the task identified with "task_id". */
00243   P_TCB task_context;
00244 
00245   if (task_id == 0 || task_id == os_tsk.run->task_id) {
00246     /* Terminate itself. */
00247     os_tsk.run->state     = INACTIVE;
00248     os_tsk.run->tsk_stack = rt_get_PSP ();
00249     rt_stk_check ();
00250     os_active_TCB[os_tsk.run->task_id-1] = NULL;
00251     rt_free_box (mp_stk, os_tsk.run->stack);
00252     os_tsk.run->stack = NULL;
00253     DBG_TASK_NOTIFY(os_tsk.run, __FALSE);
00254     rt_free_box (mp_tcb, os_tsk.run);
00255     os_tsk.run = NULL;
00256     rt_dispatch (NULL);
00257     /* The program should never come to this point. */
00258   }
00259   else {
00260     /* Find the task in the "os_active_TCB" array. */
00261     if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
00262       /* Task with "task_id" not found or not started. */
00263       return (OS_R_NOK);
00264     }
00265     task_context = os_active_TCB[task_id-1];
00266     rt_rmv_list (task_context);
00267     rt_rmv_dly (task_context);
00268     os_active_TCB[task_id-1] = NULL;
00269     rt_free_box (mp_stk, task_context->stack);
00270     task_context->stack = NULL;
00271     DBG_TASK_NOTIFY(task_context, __FALSE);
00272     rt_free_box (mp_tcb, task_context);
00273   }
00274   return (OS_R_OK);
00275 }
00276 
00277 
00278 /*--------------------------- rt_sys_init -----------------------------------*/
00279 
00280 void rt_sys_init (FUNCP first_task, U32 prio_stksz, void *stk) {
00281   /* Initialize system and start up task declared with "first_task". */
00282   U32 i;
00283 
00284   DBG_INIT();
00285 
00286   /* Initialize dynamic memory and task TCB pointers to NULL. */
00287   for (i = 0; i < os_maxtaskrun; i++) {
00288     os_active_TCB[i] = NULL;
00289   }
00290   rt_init_box (&mp_tcb, mp_tcb_size, sizeof(struct OS_TCB));
00291   rt_init_box (&mp_stk, mp_stk_size, BOX_ALIGN_8 | (U16)(os_stackinfo));
00292   rt_init_box ((U32 *)m_tmr, mp_tmr_size, sizeof(struct OS_TMR));
00293 
00294   /* Set up TCB of idle demon */
00295   os_idle_TCB.task_id    = 255;
00296   os_idle_TCB.priv_stack = 0;
00297   rt_init_context (&os_idle_TCB, 0, os_idle_demon);
00298 
00299   /* Set up ready list: initially empty */
00300   os_rdy.cb_type = HCB;
00301   os_rdy.p_lnk   = NULL;
00302   /* Set up delay list: initially empty */
00303   os_dly.cb_type = HCB;
00304   os_dly.p_dlnk  = NULL;
00305   os_dly.p_blnk  = NULL;
00306   os_dly.delta_time = 0;
00307 
00308   /* Fix SP and systemvariables to assume idle task is running  */
00309   /* Transform main program into idle task by assuming idle TCB */
00310   rt_set_PSP (os_idle_TCB.tsk_stack+32);
00311   os_tsk.run = &os_idle_TCB;
00312   os_tsk.run->state = RUNNING;
00313 
00314   /* Initialize ps queue */
00315   os_psq->first = 0;
00316   os_psq->last  = 0;
00317   os_psq->size  = os_fifo_size;
00318 
00319   rt_init_robin ();
00320 
00321   /* Intitialize SVC and PendSV */
00322   rt_svc_init ();
00323 
00324   /* Intitialize system clock timer */
00325   os_tick_irqn = os_tick_init ();
00326   if (os_tick_irqn >= 0) {
00327     OS_X_INIT(os_tick_irqn);
00328   }
00329 
00330   /* Start up first user task before entering the endless loop */
00331   rt_tsk_create (first_task, prio_stksz, stk, NULL);
00332 }
00333 
00334 /*----------------------------------------------------------------------------
00335  * end of file
00336  *---------------------------------------------------------------------------*/