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/*

 * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved.

 *

 * This software may be freely used, copied, modified, and distributed

 * provided that the above copyright notice is preserved in all copies of the

 * software.

 */

/* -*-C-*-

 *

 * $Revision: 1.1.1.1 $

 *     $Date: 2001-05-18 11:16:37 $

 *

 *

 *   Project: ANGEL

 *

 *     Title: Public interface to buffer management

 */

#ifndef angel_buffers_h

#define angel_buffers_h

#include "chandefs.h"           /* CHAN_HEADER_SIZE */

/* the handle to a buffer */

typedef unsigned char *p_Buffer;

/*

 * Angel Packets are structured as a fixed size header, followed

 * by the packet data

 */

#ifdef TARGET

# define BUFFERDATA(b)  (b)     /* channels layer takes care of it */

#else

# define BUFFERDATA(b)  (&((b)[CHAN_HEADER_SIZE]))

#endif

/*

 * The buffer management function prototypes are only applicable

 * when compiling target code

 */

#ifdef TARGET

/*

 * Function: Angel_BufferQuerySizes

 *  Purpose: Request infomation on the default and maximum buffer sizes

 *           that can be allocated

 *

 *   Params:

 *             In/Out: default_size, max_size: pointers to place the

 *                     sizes in on return

 */

void Angel_BufferQuerySizes(unsigned int *default_size,

                            unsigned int *max_size );

/*

 * Function: Angel_RxEnginBuffersLeft

 *  Purpose: return the number of free buffers

 *

 *   Params:

 *            Returns: number of free buffers

 */

unsigned int Angel_BuffersLeft( void );

/*

 * Function: Angel_BufferAlloc

 *  Purpose: allocate a buffer that is at least req_size bytes long

 *

 *   Params:

 *              Input: req_size     the required size of the buffer

 *

 *              Returns: pointer to the buffer NULL if unable to

 *                       fulfil the request

 */

p_Buffer     Angel_BufferAlloc(unsigned int  req_size);

/*

 * Function: Angel_BufferRelease

 *  Purpose: release a buffer back to the free pool

 *

 *   Params:

 *              Input: pointer to the buffer to free

 */

void Angel_BufferRelease(p_Buffer buffer);

/* return values for angel_InitBuffers */

typedef enum buf_init_error{

  INIT_BUF_OK,

  INIT_BUF_FAIL

} buf_init_error;

/*

 * Function: Angel_InitBuffers

 *  Purpose: Initalised and malloc the buffer pool

 *

 *   Params:

 *              Returns: see above

 */

buf_init_error  Angel_InitBuffers(void);

#endif /* def TARGET */

#endif /* ndef angel_buffers_h */

/* EOF buffers.h */