WebSVN - shark - Blame - Rev 1618 - /shark/branches/xen/drivers/net/netbuff.c

Rev	Author	Line No.	Line
629	giacomo	1	/*
		2	* Project: S.Ha.R.K.
		3	*
		4	* Coordinators:
		5	* Giorgio Buttazzo <giorgio@sssup.it>
		6	* Paolo Gai <pj@gandalf.sssup.it>
		7	*
		8	* Authors :
		9	* Paolo Gai <pj@gandalf.sssup.it>
		10	* Massimiliano Giorgi <massy@gandalf.sssup.it>
		11	* Luca Abeni <luca@gandalf.sssup.it>
		12	* (see the web pages for full authors list)
		13	*
		14	* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
		15	*
		16	* http://www.sssup.it
		17	* http://retis.sssup.it
		18	* http://shark.sssup.it
		19	*/
		20
		21	/**
		22	------------
		23	CVS : $Id: netbuff.c,v 1.3 2004-05-11 14:30:50 giacomo Exp $
		24
		25	File: $File$
		26	Revision: $Revision: 1.3 $
		27	Last update: $Date: 2004-05-11 14:30:50 $
		28	------------
		29	**/
		30
		31	/*
		32	* Copyright (C) 2000 Luca Abeni
		33	*
		34	* This program is free software; you can redistribute it and/or modify
		35	* it under the terms of the GNU General Public License as published by
		36	* the Free Software Foundation; either version 2 of the License, or
		37	* (at your option) any later version.
		38	*
		39	* This program is distributed in the hope that it will be useful,
		40	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		41	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		42	* GNU General Public License for more details.
		43	*
		44	* You should have received a copy of the GNU General Public License
		45	* along with this program; if not, write to the Free Software
		46	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		47	*
		48	*/
		49
		50	/* Author: Luca Abeni */
		51	/* Date: 25/9/1997 */
		52
		53	/* File: NetBuff.c */
		54	/* Revision: 1.00 */
		55
		56	/*
		57	This module manages all the buffers used by the network driver:
		58	the buffers are grouped in netbuff structures (initialized by
		59	netbuff_init) and can be allocated by netbuff_get or released
		60	by netbuff_released. A netbuff_sequentialget function is also
		61	provided for beeing used by tasks that have their own buffer (
		62	if a buffer can be allocated by only one task, it is useless to
		63	allocate it in mutual exclusion). It is usefull for the receive
		64	buffers allocated by the receive process.
		65	*/
		66	#include <kernel/kern.h>
		67	#include <semaphore.h>
		68
		69	#include "netbuff.h"
		70
		71	/* Init the buffer structures */
		72	void netbuff_init(struct netbuff *netb, BYTE nbuffs, WORD buffdim)
		73	{
		74	int i;
		75
		76	kern_cli();
		77	netb->b = kern_alloc(nbuffs * buffdim);
		78	netb->pb = kern_alloc(nbuffs * sizeof(void *));
		79	netb->free = kern_alloc(nbuffs * sizeof(char));
		80	kern_sti();
		81	if ((netb->b == 0) \|\| (netb->pb ==0) \|\| (netb->free == 0)) {
		82	kern_raise(XNETBUFF_INIT_EXC,exec_shadow);
		83	}
		84	netb->nbuffs = nbuffs;
		85	for (i = 0; i < nbuffs; i++) {
		86	netb->pb[i] = netb->b + (i * buffdim);
		87	netb->free[i] = 1;
		88	}
		89	sem_init(&(netb->buffersem), 0, nbuffs);
		90	}
		91
		92	/*
		93	Get the first free buffer in the netb pool. All the tasks can call this
		94	function, so a kern_cli is needed
		95	*/
		96	void netbuff_get(struct netbuff netb, BYTE to)
		97	{
		98	int i, done;
		99	static int mycount = 0;
		100
		101	if (sem_xwait(&(netb->buffersem), 1, to) != 0) {
		102	return NULL;
		103	} else {
		104	mycount++;
		105	}
		106
		107	done = 0; i = 0;
		108	kern_cli();
		109	while ((i < netb->nbuffs) && !done) {
		110	if (netb->free[i]) {
		111	done = 1;
		112	netb->free[i] = 0;
		113	} else i++;
		114	}
		115	kern_sti();
		116	if (!done) {
		117	kern_raise(XNETBUFF_GET_EXC,exec_shadow);
		118	}
		119	return netb->pb[i];
		120	}
		121
		122	/*
		123	Get the first free buffer in the netb pool. This function can be called
		124	only if netb is private of the process that wants to get the buffer, so
		125	kern_cli is not needed
		126	*/
		127	void netbuff_sequentialget(struct netbuff netb, BYTE to)
		128	{
		129	int i, done;
		130
		131	if (!sem_xwait(&(netb->buffersem), 1, to)) {
		132	return NULL;
		133	}
		134
		135	done = 0; i = 0;
		136	while ((i < netb->nbuffs) && !done) {
		137	if (netb->free[i]) {
		138	done = 1;
		139	netb->free[i] = 0;
		140	} else i++;
		141	}
		142	if (!done) {
		143	kern_raise(XNETBUFF_GET_EXC,exec_shadow);
		144	}
		145	return netb->pb[i];
		146	}
		147
		148	/* Release the buffer m of the pool netb */
		149	void netbuff_release(struct netbuff netb, void m)
		150	{
		151	int i, done;
		152
		153	done = 0; i = 0;
		154	while ((i < netb->nbuffs) && !done) {
		155	if (netb->pb[i] == m) {
		156	if (netb->free[i] == 1) {
		157	cprintf("Trying to free a free buffer :( \n");
		158	kern_raise(XNETBUFF_ALREADYFREE_EXC,exec_shadow);
		159	}
		160	done = 1;
		161	netb->free[i] = 1;
		162	} else i++;
		163	}
		164	if (!done) {
		165	cprintf("Trying to free a STRANGE buffer :( \n");
		166	kern_raise(XNETBUFF_RELEASE_EXC,exec_shadow);
		167	}
		168	sem_post(&(netb->buffersem));
		169	}

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