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