//Section 4.6.8
private void InitTx()
{
//CRC offload and small packet padding
SetFlags(IxgbeDefs.HLREG0, IxgbeDefs.HLREG0_TXCRCEN | IxgbeDefs.HLREG0_TXPADEN);
//Set default buffer size allocations (section 4.6.11.3.4)
SetReg(IxgbeDefs.TXPBSIZE(0), IxgbeDefs.TXPBSIZE_40KB);
for (uint i = 1; i < 8; i++)
{
SetReg(IxgbeDefs.TXPBSIZE(i), 0);
}
//Required when not using DCB/VTd
SetReg(IxgbeDefs.DTXMXSZRQ, 0xFFFF);
ClearFlags(IxgbeDefs.RTTDCS, IxgbeDefs.RTTDCS_ARBDIS);
//Per queue config for all queues
for (uint i = 0; i < TxQueues.Length; i++)
{
Log.Notice("Initializing TX queue {0}", i);
//Section 7.1.9 - Setup descriptor ring
uint ringSizeBytes = NumTxQueueEntries * TxDescriptorSize;
var dmaMem = MemoryHelper.AllocateDmaC(ringSizeBytes, true);
//TODO : The C version sets the allocated memory to -1 here
SetReg(IxgbeDefs.TDBAL(i), (uint)(dmaMem.PhysicalAddress & 0xFFFFFFFFL));
SetReg(IxgbeDefs.TDBAH(i), (uint)(dmaMem.PhysicalAddress >> 32));
SetReg(IxgbeDefs.TDLEN(i), (uint)ringSizeBytes);
Log.Notice("TX ring {0} physical addr: {1}", i, dmaMem.PhysicalAddress);
Log.Notice("TX ring {0} virtual addr: {1}", i, dmaMem.VirtualAddress);
//Descriptor writeback magic values, important to get good performance and low PCIe overhead
//See sec. 7.2.3.4.1 and 7.2.3.5
uint txdctl = GetReg(IxgbeDefs.TXDCTL(i));
//Seems like overflow is irrelevant here
unchecked
{
//Clear bits
txdctl &= (uint)(~(0x3F | (0x3F << 8) | (0x3F << 16)));
//From DPDK
txdctl |= (36 | (8 << 8) | (4 << 16));
}
SetReg(IxgbeDefs.TXDCTL(i), txdctl);
var queue = new IxgbeTxQueue(NumTxQueueEntries);
queue.Index = 0;
queue.DescriptorsAddr = dmaMem.VirtualAddress;
TxQueues[i] = queue;
}
//Enable DMA
SetReg(IxgbeDefs.DMATXCTL, IxgbeDefs.DMATXCTL_TE);
}
private void InitRx()
{
//Disable RX while re-configuring
ClearFlags(IxgbeDefs.RXCTRL, IxgbeDefs.RXCTRL_RXEN);
//No DCB or VT, just a single 128kb packet buffer
SetReg(IxgbeDefs.RXPBSIZE(0), IxgbeDefs.RXPBSIZE_128KB);
for (uint i = 1; i < 8; i++)
{
SetReg(IxgbeDefs.RXPBSIZE(i), 0);
}
//Always enable CRC offloading
SetFlags(IxgbeDefs.HLREG0, IxgbeDefs.HLREG0_RXCRCSTRP);
SetFlags(IxgbeDefs.RDRXCTL, IxgbeDefs.RDRXCTL_CRCSTRIP);
//Accept broadcast packets
SetFlags(IxgbeDefs.FCTRL, IxgbeDefs.FCTRL_BAM);
//Per queue config
for (uint i = 0; i < RxQueues.Length; i++)
{
Log.Notice("Initializing rx queue {0}", i);
//Enable advanced rx descriptors
SetReg(IxgbeDefs.SRRCTL(i), (GetReg(IxgbeDefs.SRRCTL(i)) & ~IxgbeDefs.SRRCTL_DESCTYPE_MASK)
| IxgbeDefs.SRRCTL_DESCTYPE_ADV_ONEBUF);
//DROP_EN causes the NIC to drop packets if no descriptors are available instead of buffering them
//A single overflowing queue can fill up the whole buffer and impact operations if not setting this
SetFlags(IxgbeDefs.SRRCTL(i), IxgbeDefs.SRRCTL_DROP_EN);
//Sec 7.1.9 - Set up descriptor ring
int ringSizeBytes = NumRxQueueEntries * RxDescriptorSize;
var dmaMem = MemoryHelper.AllocateDmaC((uint)ringSizeBytes, true);
//TODO : The C version sets the allocated memory to -1 here
SetReg(IxgbeDefs.RDBAL(i), (uint)(dmaMem.PhysicalAddress & 0xFFFFFFFFL));
SetReg(IxgbeDefs.RDBAH(i), (uint)(dmaMem.PhysicalAddress >> 32));
SetReg(IxgbeDefs.RDLEN(i), (uint)ringSizeBytes);
Log.Notice("RX ring {0} physical address: {1}", i, dmaMem.PhysicalAddress);
Log.Notice("RX ring {0} virtual address: {1}", i, dmaMem.VirtualAddress);
//Set ring to empty
SetReg(IxgbeDefs.RDH(i), 0);
SetReg(IxgbeDefs.RDT(i), 0);
var queue = new IxgbeRxQueue(NumRxQueueEntries);
queue.Index = 0;
queue.DescriptorsAddr = dmaMem.VirtualAddress;
RxQueues[i] = queue;
}
//Section 4.6.7 - set some magic bits
SetFlags(IxgbeDefs.CTRL_EXT, IxgbeDefs.CTRL_EXT_NS_DIS);
//This flag probably refers to a broken feature: It's reserved and initialized as '1' but it must be '0'
for (uint i = 0; i < RxQueues.Length; i++)
{
ClearFlags(IxgbeDefs.DCA_RXCTRL(i), 1 << 12);
}
//Start RX
SetFlags(IxgbeDefs.RXCTRL, IxgbeDefs.RXCTRL_RXEN);
}