OvmfPkg/VirtioNetDxe/SnpTransmit.c

   1 /** @file
   2
   3   Implementation of the SNP.Transmit() function and its private helpers if any.
   4
   5   Copyright (C) 2013, Red Hat, Inc.
   6   Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <Library/BaseLib.h>
  13 #include <Library/BaseMemoryLib.h>
  14 #include <Library/UefiBootServicesTableLib.h>
  15
  16 #include "VirtioNet.h"
  17
  18 /**
  19   Places a packet in the transmit queue of a network interface.
  20
  21   @param  This       The protocol instance pointer.
  22   @param  HeaderSize The size, in bytes, of the media header to be filled in by
  23                      the Transmit() function. If HeaderSize is non-zero, then
  24                      it must be equal to This->Mode->MediaHeaderSize and the
  25                      DestAddr and Protocol parameters must not be NULL.
  26   @param  BufferSize The size, in bytes, of the entire packet (media header and
  27                      data) to be transmitted through the network interface.
  28   @param  Buffer     A pointer to the packet (media header followed by data) to
  29                      be transmitted. This parameter cannot be NULL. If
  30                      HeaderSize is zero, then the media header in Buffer must
  31                      already be filled in by the caller. If HeaderSize is
  32                      non-zero, then the media header will be filled in by the
  33                      Transmit() function.
  34   @param  SrcAddr    The source HW MAC address. If HeaderSize is zero, then
  35                      this parameter is ignored. If HeaderSize is non-zero and
  36                      SrcAddr is NULL, then This->Mode->CurrentAddress is used
  37                      for the source HW MAC address.
  38   @param  DestAddr   The destination HW MAC address. If HeaderSize is zero,
  39                      then this parameter is ignored.
  40   @param  Protocol   The type of header to build. If HeaderSize is zero, then
  41                      this parameter is ignored. See RFC 1700, section "Ether
  42                      Types", for examples.
  43
  44   @retval EFI_SUCCESS           The packet was placed on the transmit queue.
  45   @retval EFI_NOT_STARTED       The network interface has not been started.
  46   @retval EFI_NOT_READY         The network interface is too busy to accept
  47                                 this transmit request.
  48   @retval EFI_BUFFER_TOO_SMALL  The BufferSize parameter is too small.
  49   @retval EFI_INVALID_PARAMETER One or more of the parameters has an
  50                                 unsupported value.
  51   @retval EFI_DEVICE_ERROR      The command could not be sent to the network
  52                                 interface.
  53   @retval EFI_UNSUPPORTED       This function is not supported by the network
  54                                 interface.
  55
  56 **/
  57 EFI_STATUS
  58 EFIAPI
  59 VirtioNetTransmit (
  60   IN EFI_SIMPLE_NETWORK_PROTOCOL  *This,
  61   IN UINTN                        HeaderSize,
  62   IN UINTN                        BufferSize,
  63   IN /* +OUT! */ VOID             *Buffer,
  64   IN EFI_MAC_ADDRESS              *SrcAddr  OPTIONAL,
  65   IN EFI_MAC_ADDRESS              *DestAddr OPTIONAL,
  66   IN UINT16                       *Protocol OPTIONAL
  67   )
  68 {
  69   VNET_DEV              *Dev;
  70   EFI_TPL               OldTpl;
  71   EFI_STATUS            Status;
  72   UINT16                DescIdx;
  73   UINT16                AvailIdx;
  74   EFI_PHYSICAL_ADDRESS  DeviceAddress;
  75
  76   if ((This == NULL) || (BufferSize == 0) || (Buffer == NULL)) {
  77     return EFI_INVALID_PARAMETER;
  78   }
  79
  80   Dev    = VIRTIO_NET_FROM_SNP (This);
  81   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  82   switch (Dev->Snm.State) {
  83     case EfiSimpleNetworkStopped:
  84       Status = EFI_NOT_STARTED;
  85       goto Exit;
  86     case EfiSimpleNetworkStarted:
  87       Status = EFI_DEVICE_ERROR;
  88       goto Exit;
  89     default:
  90       break;
  91   }
  92
  93   if (BufferSize < Dev->Snm.MediaHeaderSize) {
  94     Status = EFI_BUFFER_TOO_SMALL;
  95     goto Exit;
  96   }
  97
  98   if (BufferSize > Dev->Snm.MediaHeaderSize + Dev->Snm.MaxPacketSize) {
  99     Status = EFI_INVALID_PARAMETER;
 100     goto Exit;
 101   }
 102
 103   //
 104   // check if we have room for transmission
 105   //
 106   ASSERT (Dev->TxCurPending <= Dev->TxMaxPending);
 107   if (Dev->TxCurPending == Dev->TxMaxPending) {
 108     Status = EFI_NOT_READY;
 109     goto Exit;
 110   }
 111
 112   //
 113   // the caller may want us to fill in the media header:
 114   // dst MAC, src MAC, Ethertype
 115   //
 116   if (HeaderSize != 0) {
 117     UINT8  *Ptr;
 118
 119     if ((HeaderSize != Dev->Snm.MediaHeaderSize) ||
 120         (DestAddr == NULL) || (Protocol == NULL))
 121     {
 122       Status = EFI_INVALID_PARAMETER;
 123       goto Exit;
 124     }
 125
 126     Ptr = Buffer;
 127     ASSERT (SIZE_OF_VNET (Mac) <= sizeof (EFI_MAC_ADDRESS));
 128
 129     CopyMem (Ptr, DestAddr, SIZE_OF_VNET (Mac));
 130     Ptr += SIZE_OF_VNET (Mac);
 131
 132     CopyMem (
 133       Ptr,
 134       (SrcAddr == NULL) ? &Dev->Snm.CurrentAddress : SrcAddr,
 135       SIZE_OF_VNET (Mac)
 136       );
 137     Ptr += SIZE_OF_VNET (Mac);
 138
 139     *Ptr++ = (UINT8)(*Protocol >> 8);
 140     *Ptr++ = (UINT8)*Protocol;
 141
 142     ASSERT ((UINTN)(Ptr - (UINT8 *)Buffer) == Dev->Snm.MediaHeaderSize);
 143   }
 144
 145   //
 146   // Map the transmit buffer system physical address to device address.
 147   //
 148   Status = VirtioNetMapTxBuf (
 149              Dev,
 150              Buffer,
 151              BufferSize,
 152              &DeviceAddress
 153              );
 154   if (EFI_ERROR (Status)) {
 155     Status = EFI_DEVICE_ERROR;
 156     goto Exit;
 157   }
 158
 159   //
 160   // virtio-0.9.5, 2.4.1 Supplying Buffers to The Device
 161   //
 162   DescIdx                            = Dev->TxFreeStack[Dev->TxCurPending++];
 163   Dev->TxRing.Desc[DescIdx + 1].Addr = DeviceAddress;
 164   Dev->TxRing.Desc[DescIdx + 1].Len  = (UINT32)BufferSize;
 165
 166   //
 167   // the available index is never written by the host, we can read it back
 168   // without a barrier
 169   //
 170   AvailIdx                                                   = *Dev->TxRing.Avail.Idx;
 171   Dev->TxRing.Avail.Ring[AvailIdx++ % Dev->TxRing.QueueSize] = DescIdx;
 172
 173   MemoryFence ();
 174   *Dev->TxRing.Avail.Idx = AvailIdx;
 175
 176   MemoryFence ();
 177   Status = Dev->VirtIo->SetQueueNotify (Dev->VirtIo, VIRTIO_NET_Q_TX);
 178
 179 Exit:
 180   gBS->RestoreTPL (OldTpl);
 181   return Status;
 182 }