rt_MemBox.c

00001 /*----------------------------------------------------------------------------
00002  *      RL-ARM - RTX
00003  *----------------------------------------------------------------------------
00004  *      Name:    RT_MEMBOX.C
00005  *      Purpose: Interface functions for fixed memory block management system
00006  *      Rev.:    V4.60
00007  *----------------------------------------------------------------------------
00008  *
00009  * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH
00010  * All rights reserved.
00011  * Redistribution and use in source and binary forms, with or without
00012  * modification, are permitted provided that the following conditions are met:
00013  *  - Redistributions of source code must retain the above copyright
00014  *    notice, this list of conditions and the following disclaimer.
00015  *  - Redistributions in binary form must reproduce the above copyright
00016  *    notice, this list of conditions and the following disclaimer in the
00017  *    documentation and/or other materials provided with the distribution.
00018  *  - Neither the name of ARM  nor the names of its contributors may be used 
00019  *    to endorse or promote products derived from this software without 
00020  *    specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
00023  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
00024  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00025  * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
00026  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00027  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
00028  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
00029  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
00030  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
00031  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00032  * POSSIBILITY OF SUCH DAMAGE.
00033  *---------------------------------------------------------------------------*/
00034 
00035 #include "rt_TypeDef.h"
00036 #include "RTX_Conf.h"
00037 #include "rt_System.h"
00038 #include "rt_MemBox.h"
00039 #include "rt_HAL_CM.h"
00040 
00041 /*----------------------------------------------------------------------------
00042  *      Global Functions
00043  *---------------------------------------------------------------------------*/
00044 
00045 
00046 /*--------------------------- _init_box -------------------------------------*/
00047 
00048 int _init_box  (void *box_mem, U32 box_size, U32 blk_size) {
00049   /* Initialize memory block system, returns 0 if OK, 1 if fails. */
00050   void *end;
00051   void *blk;
00052   void *next;
00053   U32  sizeof_bm;
00054 
00055   /* Create memory structure. */
00056   if (blk_size & BOX_ALIGN_8) {
00057     /* Memory blocks 8-byte aligned. */ 
00058     blk_size = ((blk_size & ~BOX_ALIGN_8) + 7) & ~7;
00059     sizeof_bm = (sizeof (struct OS_BM) + 7) & ~7;
00060   }
00061   else {
00062     /* Memory blocks 4-byte aligned. */
00063     blk_size = (blk_size + 3) & ~3;
00064     sizeof_bm = sizeof (struct OS_BM);
00065   }
00066   if (blk_size == 0) {
00067     return (1);
00068   }
00069   if ((blk_size + sizeof_bm) > box_size) {
00070     return (1);
00071   }
00072   /* Create a Memory structure. */
00073   blk = ((U8 *) box_mem) + sizeof_bm;
00074   ((P_BM) box_mem)->free = blk;
00075   end = ((U8 *) box_mem) + box_size;
00076   ((P_BM) box_mem)->end      = end;
00077   ((P_BM) box_mem)->blk_size = blk_size;
00078 
00079   /* Link all free blocks using offsets. */
00080   end = ((U8 *) end) - blk_size;
00081   while (1)  {
00082     next = ((U8 *) blk) + blk_size;
00083     if (next > end)  break;
00084     *((void **)blk) = next;
00085     blk = next;
00086   }
00087   /* end marker */
00088   *((void **)blk) = 0;
00089   return (0);
00090 }
00091 
00092 /*--------------------------- rt_alloc_box ----------------------------------*/
00093 
00094 void *rt_alloc_box (void *box_mem) {
00095   /* Allocate a memory block and return start address. */
00096   void **free;
00097 #ifndef __USE_EXCLUSIVE_ACCESS
00098   int  irq_dis;
00099 
00100   irq_dis = __disable_irq ();
00101   free = ((P_BM) box_mem)->free;
00102   if (free) {
00103     ((P_BM) box_mem)->free = *free;
00104   }
00105   if (!irq_dis) __enable_irq ();
00106 #else
00107   do {
00108     if ((free = (void **)__ldrex(&((P_BM) box_mem)->free)) == 0) {
00109       __clrex();
00110       break;
00111     }
00112   } while (__strex((U32)*free, &((P_BM) box_mem)->free));
00113 #endif
00114   return (free);
00115 }
00116 
00117 
00118 /*--------------------------- _calloc_box -----------------------------------*/
00119 
00120 void *_calloc_box (void *box_mem)  {
00121   /* Allocate a 0-initialized memory block and return start address. */
00122   void *free;
00123   U32 *p;
00124   U32 i;
00125 
00126   free = _alloc_box (box_mem);
00127   if (free)  {
00128     p = free;
00129     for (i = ((P_BM) box_mem)->blk_size; i; i -= 4)  {
00130       *p = 0;
00131       p++;
00132     }
00133   }
00134   return (free);
00135 }
00136 
00137 
00138 /*--------------------------- rt_free_box -----------------------------------*/
00139 
00140 int rt_free_box (void *box_mem, void *box) {
00141   /* Free a memory block, returns 0 if OK, 1 if box does not belong to box_mem */
00142 #ifndef __USE_EXCLUSIVE_ACCESS
00143   int irq_dis;
00144 #endif
00145 
00146   if (box < box_mem || box >= ((P_BM) box_mem)->end) {
00147     return (1);
00148   }
00149 
00150 #ifndef __USE_EXCLUSIVE_ACCESS
00151   irq_dis = __disable_irq ();
00152   *((void **)box) = ((P_BM) box_mem)->free;
00153   ((P_BM) box_mem)->free = box;
00154   if (!irq_dis) __enable_irq ();
00155 #else
00156   do {
00157     *((void **)box) = (void *)__ldrex(&((P_BM) box_mem)->free);
00158   } while (__strex ((U32)box, &((P_BM) box_mem)->free));
00159 #endif
00160   return (0);
00161 }
00162 
00163 /*----------------------------------------------------------------------------
00164  * end of file
00165  *---------------------------------------------------------------------------*/
00166