OvmfPkg: VirtioNetDxe: implement Tx: SNP.Transmit and SNP.GetStatus

Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Jordan Justen <jordan.l.justen@intel.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14413 6f19259b-4bc3-4df7-8a09-765794883524
2013-06-14 07:40:24 +00:00
parent e12fadc3cf
commit b6dfc654c8
2 changed files with 327 additions and 0 deletions
--- a/OvmfPkg/VirtioNetDxe/SnpGetStatus.c
+++ b/OvmfPkg/VirtioNetDxe/SnpGetStatus.c
@@ -0,0 +1,158 @@
+/** @file
+
+  Implementation of the SNP.GetStatus() function and its private helpers if
+  any.
+
+  Copyright (C) 2013, Red Hat, Inc.
+  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include "VirtioNet.h"
+
+/**
+  Reads the current interrupt status and recycled transmit buffer status from
+  a network interface.
+
+  @param  This            The protocol instance pointer.
+  @param  InterruptStatus A pointer to the bit mask of the currently active
+                          interrupts If this is NULL, the interrupt status will
+                          not be read from the device. If this is not NULL, the
+                          interrupt status will be read from the device. When
+                          the  interrupt status is read, it will also be
+                          cleared. Clearing the transmit  interrupt does not
+                          empty the recycled transmit buffer array.
+  @param  TxBuf           Recycled transmit buffer address. The network
+                          interface will not transmit if its internal recycled
+                          transmit buffer array is full. Reading the transmit
+                          buffer does not clear the transmit interrupt. If this
+                          is NULL, then the transmit buffer status will not be
+                          read. If there are no transmit buffers to recycle and
+                          TxBuf is not NULL, * TxBuf will be set to NULL.
+
+  @retval EFI_SUCCESS           The status of the network interface was
+                                retrieved.
+  @retval EFI_NOT_STARTED       The network interface has not been started.
+  @retval EFI_INVALID_PARAMETER One or more of the parameters has an
+                                unsupported value.
+  @retval EFI_DEVICE_ERROR      The command could not be sent to the network
+                                interface.
+  @retval EFI_UNSUPPORTED       This function is not supported by the network
+                                interface.
+
+**/
+
+EFI_STATUS
+EFIAPI
+VirtioNetGetStatus (
+  IN EFI_SIMPLE_NETWORK_PROTOCOL *This,
+  OUT UINT32                     *InterruptStatus OPTIONAL,
+  OUT VOID                       **TxBuf OPTIONAL
+  )
+{
+  VNET_DEV   *Dev;
+  EFI_TPL    OldTpl;
+  EFI_STATUS Status;
+  UINT16     RxCurUsed;
+  UINT16     TxCurUsed;
+
+  if (This == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = VIRTIO_NET_FROM_SNP (This);
+  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
+  switch (Dev->Snm.State) {
+  case EfiSimpleNetworkStopped:
+    Status = EFI_NOT_STARTED;
+    goto Exit;
+  case EfiSimpleNetworkStarted:
+    Status = EFI_DEVICE_ERROR;
+    goto Exit;
+  default:
+    break;
+  }
+
+  //
+  // update link status
+  //
+  if (Dev->Snm.MediaPresentSupported) {
+    UINT16 LinkStatus;
+
+    Status = VIRTIO_CFG_READ (Dev, VhdrLinkStatus, &LinkStatus);
+    if (EFI_ERROR (Status)) {
+      goto Exit;
+    }
+    Dev->Snm.MediaPresent = !!(LinkStatus & VIRTIO_NET_S_LINK_UP);
+  }
+
+  //
+  // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
+  //
+  MemoryFence ();
+  RxCurUsed = *Dev->RxRing.Used.Idx;
+  TxCurUsed = *Dev->TxRing.Used.Idx;
+
+  if (InterruptStatus != NULL) {
+    //
+    // report the receive interrupt if there is data available for reception,
+    // report the transmit interrupt if we have transmitted at least one buffer
+    //
+    *InterruptStatus = 0;
+    if (Dev->RxLastUsed != RxCurUsed) {
+      *InterruptStatus |= EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT;
+    }
+    if (Dev->TxLastUsed != TxCurUsed) {
+      ASSERT (Dev->TxCurPending > 0);
+      *InterruptStatus |= EFI_SIMPLE_NETWORK_TRANSMIT_INTERRUPT;
+    }
+  }
+
+  if (TxBuf != NULL) {
+    if (Dev->TxLastUsed == TxCurUsed) {
+      *TxBuf = NULL;
+    }
+    else {
+      UINT16 UsedElemIdx;
+      UINT32 DescIdx;
+
+      //
+      // fetch the first descriptor among those that the hypervisor reports
+      // completed
+      //
+      ASSERT (Dev->TxCurPending > 0);
+      ASSERT (Dev->TxCurPending <= Dev->TxMaxPending);
+
+      UsedElemIdx = Dev->TxLastUsed++ % Dev->TxRing.QueueSize;
+      DescIdx = Dev->TxRing.Used.UsedElem[UsedElemIdx].Id;
+      ASSERT (DescIdx < 2 * Dev->TxMaxPending - 1);
+
+      //
+      // report buffer address to caller that has been enqueued by caller
+      //
+      *TxBuf = (VOID *) Dev->TxRing.Desc[DescIdx + 1].Addr;
+
+      //
+      // now this descriptor can be used again to enqueue a transmit buffer
+      //
+      Dev->TxFreeStack[--Dev->TxCurPending] = (UINT16) DescIdx;
+    }
+  }
+
+  Status = EFI_SUCCESS;
+
+Exit:
+  gBS->RestoreTPL (OldTpl);
+  return Status;
+}