/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.driver.net._3c90x;
import org.jnode.net.SocketBuffer;
import org.jnode.net.ethernet.EthernetConstants;
import org.jnode.system.resource.MemoryResource;
import org.jnode.system.resource.ResourceManager;
import org.vmmagic.unboxed.Address;
/**
* @author epr
*/
public class _3c90xRxRing implements _3c90xConstants {
private static final int UPD_SIZE = 16;
private static final int FRAME_SIZE = EthernetConstants.ETH_FRAME_LEN;
/**
* The #frames in this ring
*/
private final int nrFrames;
/**
* The actual data
*/
private final byte[] data;
/**
* MemoryResource mapper around data
*/
private final MemoryResource mem;
/**
* Offset within mem of first UDP
*/
private final int firstUPDOffset;
/**
* Offset within mem of first ethernet frame
*/
private final int firstFrameOffset;
/**
* 32-bit address first UDP
*/
private final Address firstUPDAddress;
/**
* 32-bit address of first ethernet frame
*/
private final Address firstFrameAddress;
/**
* Create a new instance
*
* @param nrFrames The number of complete ethernet frames in this ring.
* @param rm
*/
public _3c90xRxRing(int nrFrames, ResourceManager rm) {
// Create a large enough buffer
final int size = (nrFrames * (UPD_SIZE + FRAME_SIZE)) + 16/* alignment */;
this.data = new byte[size];
this.nrFrames = nrFrames;
this.mem = rm.asMemoryResource(data);
final Address memAddr = mem.getAddress();
int addr = memAddr.toInt();
int offset = 0;
// Align on 16-byte boundary
while ((addr & 15) != 0) {
addr++;
offset++;
}
this.firstUPDOffset = offset;
this.firstUPDAddress = memAddr.add(firstUPDOffset);
this.firstFrameOffset = firstUPDOffset + (nrFrames * UPD_SIZE);
this.firstFrameAddress = memAddr.add(firstFrameOffset);
}
/**
* Initialize this ring to its default (empty) state
*/
public void initialize() {
// Setup each UPD
for (int i = 0; i < nrFrames; i++) {
final int updOffset = firstUPDOffset + (i * UPD_SIZE);
// Set next UPD ptr
if (i + 1 < nrFrames) {
mem.setInt(updOffset + 0, firstUPDAddress.toInt() + ((i + 1) * UPD_SIZE));
} else {
mem.setInt(updOffset + 0, firstUPDAddress.toInt());
}
// Set pkt status
mem.setInt(updOffset + 4, 0);
// Set fragment address
mem.setInt(updOffset + 8, firstFrameAddress.toInt() + (i * FRAME_SIZE));
// Set fragment size
mem.setInt(updOffset + 12, FRAME_SIZE | (1 << 31));
}
}
/**
* Gets the packet status of the UPD at the given index
*
* @param index
*/
public int getPktStatus(int index) {
final int updOffset = firstUPDOffset + (index * UPD_SIZE);
return mem.getInt(updOffset + 4);
}
/**
* Sets the packet status of the UPD at the given index
*
* @param index
* @param value The new pkt status value
*/
public void setPktStatus(int index, int value) {
final int updOffset = firstUPDOffset + (index * UPD_SIZE);
mem.setInt(updOffset + 4, value);
}
/**
* Gets the packet data of UPD with the given index into a SocketBuffer
*
* @param index
*/
public SocketBuffer getPacket(int index) {
final int updOffset = firstUPDOffset + (index * UPD_SIZE);
final int frameOffset = firstFrameOffset + (index * FRAME_SIZE);
final int pktStatus = mem.getInt(updOffset + 4);
final int pktLen = pktStatus & upPktLenMask;
final SocketBuffer skbuf = new SocketBuffer();
skbuf.append(data, frameOffset, pktLen);
return skbuf;
}
/**
* Gets the address of the first UPD of this ring.
*/
public Address getFirstUPDAddress() {
return firstUPDAddress;
}
/**
* Gets the number of frames of this ring
*/
public int getNrFrames() {
return nrFrames;
}
}