Home | History | Annotate | Download | only in VirtioNetDxe 
      1 /** @file
      2 
      3   Implements
      4   - the SNM.WaitForPacket EVT_NOTIFY_WAIT event,
      5   - the EVT_SIGNAL_EXIT_BOOT_SERVICES event
      6   for the virtio-net driver.
      7 
      8   Copyright (C) 2013, Red Hat, Inc.
      9   Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
     10 
     11   This program and the accompanying materials are licensed and made available
     12   under the terms and conditions of the BSD License which accompanies this
     13   distribution. The full text of the license may be found at
     14   http://opensource.org/licenses/bsd-license.php
     15 
     16   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
     17   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     18 
     19 **/
     20 
     21 #include <Library/BaseLib.h>
     22 #include <Library/UefiBootServicesTableLib.h>
     23 
     24 #include "VirtioNet.h"
     25 
     26 /**
     27   Invoke a notification event
     28 
     29   @param  Event                 Event whose notification function is being
     30                                 invoked.
     31   @param  Context               The pointer to the notification function's
     32                                 context, which is implementation-dependent.
     33 
     34 **/
     35 
     36 VOID
     37 EFIAPI
     38 VirtioNetIsPacketAvailable (
     39   IN  EFI_EVENT Event,
     40   IN  VOID      *Context
     41   )
     42 {
     43   //
     44   // This callback has been enqueued by an external application and is
     45   // running at TPL_CALLBACK already.
     46   //
     47   // The WaitForPacket logic is similar to that of WaitForKey. The former has
     48   // almost no documentation in either the UEFI-2.3.1+errC spec or the
     49   // DWG-2.3.1, but WaitForKey does have some.
     50   //
     51   VNET_DEV *Dev;
     52   UINT16   RxCurUsed;
     53 
     54   Dev = Context;
     55   if (Dev->Snm.State != EfiSimpleNetworkInitialized) {
     56     return;
     57   }
     58 
     59   //
     60   // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
     61   //
     62   MemoryFence ();
     63   RxCurUsed = *Dev->RxRing.Used.Idx;
     64   MemoryFence ();
     65 
     66   if (Dev->RxLastUsed != RxCurUsed) {
     67     gBS->SignalEvent (&Dev->Snp.WaitForPacket);
     68   }
     69 }
     70 
     71 VOID
     72 EFIAPI
     73 VirtioNetExitBoot (
     74   IN  EFI_EVENT Event,
     75   IN  VOID      *Context
     76   )
     77 {
     78   //
     79   // This callback has been enqueued by ExitBootServices() and is running at
     80   // TPL_CALLBACK already.
     81   //
     82   // Shut down pending transfers according to DWG-2.3.1, "25.5.1 Exit Boot
     83   // Services Event".
     84   //
     85   VNET_DEV *Dev;
     86 
     87   Dev = Context;
     88   if (Dev->Snm.State == EfiSimpleNetworkInitialized) {
     89     Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
     90   }
     91 }
     92