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
VirtioNetIsPacketAvailable(IN EFI_EVENT Event,IN VOID * Context)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
VirtioNetExitBoot(IN EFI_EVENT Event,IN VOID * Context)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