1 /** @file
2
3 Implementation of the SNP.GetStatus() function and its private helpers if
4 any.
5
6 Copyright (C) 2013, Red Hat, Inc.
7 Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
8
9 This program and the accompanying materials are licensed and made available
10 under the terms and conditions of the BSD License which accompanies this
11 distribution. The full text of the license may be found at
12 http://opensource.org/licenses/bsd-license.php
13
14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
15 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
16
17 **/
18
19 #include <Library/BaseLib.h>
20 #include <Library/UefiBootServicesTableLib.h>
21
22 #include "VirtioNet.h"
23
24 /**
25 Reads the current interrupt status and recycled transmit buffer status from
26 a network interface.
27
28 @param This The protocol instance pointer.
29 @param InterruptStatus A pointer to the bit mask of the currently active
30 interrupts If this is NULL, the interrupt status will
31 not be read from the device. If this is not NULL, the
32 interrupt status will be read from the device. When
33 the interrupt status is read, it will also be
34 cleared. Clearing the transmit interrupt does not
35 empty the recycled transmit buffer array.
36 @param TxBuf Recycled transmit buffer address. The network
37 interface will not transmit if its internal recycled
38 transmit buffer array is full. Reading the transmit
39 buffer does not clear the transmit interrupt. If this
40 is NULL, then the transmit buffer status will not be
41 read. If there are no transmit buffers to recycle and
42 TxBuf is not NULL, * TxBuf will be set to NULL.
43
44 @retval EFI_SUCCESS The status of the network interface was
45 retrieved.
46 @retval EFI_NOT_STARTED The network interface has not been started.
47 @retval EFI_INVALID_PARAMETER One or more of the parameters has an
48 unsupported value.
49 @retval EFI_DEVICE_ERROR The command could not be sent to the network
50 interface.
51 @retval EFI_UNSUPPORTED This function is not supported by the network
52 interface.
53
54 **/
55
56 EFI_STATUS
57 EFIAPI
VirtioNetGetStatus(IN EFI_SIMPLE_NETWORK_PROTOCOL * This,OUT UINT32 * InterruptStatus OPTIONAL,OUT VOID ** TxBuf OPTIONAL)58 VirtioNetGetStatus (
59 IN EFI_SIMPLE_NETWORK_PROTOCOL *This,
60 OUT UINT32 *InterruptStatus OPTIONAL,
61 OUT VOID **TxBuf OPTIONAL
62 )
63 {
64 VNET_DEV *Dev;
65 EFI_TPL OldTpl;
66 EFI_STATUS Status;
67 UINT16 RxCurUsed;
68 UINT16 TxCurUsed;
69
70 if (This == NULL) {
71 return EFI_INVALID_PARAMETER;
72 }
73
74 Dev = VIRTIO_NET_FROM_SNP (This);
75 OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
76 switch (Dev->Snm.State) {
77 case EfiSimpleNetworkStopped:
78 Status = EFI_NOT_STARTED;
79 goto Exit;
80 case EfiSimpleNetworkStarted:
81 Status = EFI_DEVICE_ERROR;
82 goto Exit;
83 default:
84 break;
85 }
86
87 //
88 // update link status
89 //
90 if (Dev->Snm.MediaPresentSupported) {
91 UINT16 LinkStatus;
92
93 Status = VIRTIO_CFG_READ (Dev, LinkStatus, &LinkStatus);
94 if (EFI_ERROR (Status)) {
95 goto Exit;
96 }
97 Dev->Snm.MediaPresent =
98 (BOOLEAN) ((LinkStatus & VIRTIO_NET_S_LINK_UP) != 0);
99 }
100
101 //
102 // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
103 //
104 MemoryFence ();
105 RxCurUsed = *Dev->RxRing.Used.Idx;
106 TxCurUsed = *Dev->TxRing.Used.Idx;
107 MemoryFence ();
108
109 if (InterruptStatus != NULL) {
110 //
111 // report the receive interrupt if there is data available for reception,
112 // report the transmit interrupt if we have transmitted at least one buffer
113 //
114 *InterruptStatus = 0;
115 if (Dev->RxLastUsed != RxCurUsed) {
116 *InterruptStatus |= EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT;
117 }
118 if (Dev->TxLastUsed != TxCurUsed) {
119 ASSERT (Dev->TxCurPending > 0);
120 *InterruptStatus |= EFI_SIMPLE_NETWORK_TRANSMIT_INTERRUPT;
121 }
122 }
123
124 if (TxBuf != NULL) {
125 if (Dev->TxLastUsed == TxCurUsed) {
126 *TxBuf = NULL;
127 }
128 else {
129 UINT16 UsedElemIdx;
130 UINT32 DescIdx;
131
132 //
133 // fetch the first descriptor among those that the hypervisor reports
134 // completed
135 //
136 ASSERT (Dev->TxCurPending > 0);
137 ASSERT (Dev->TxCurPending <= Dev->TxMaxPending);
138
139 UsedElemIdx = Dev->TxLastUsed++ % Dev->TxRing.QueueSize;
140 DescIdx = Dev->TxRing.Used.UsedElem[UsedElemIdx].Id;
141 ASSERT (DescIdx < (UINT32) (2 * Dev->TxMaxPending - 1));
142
143 //
144 // report buffer address to caller that has been enqueued by caller
145 //
146 *TxBuf = (VOID *)(UINTN) Dev->TxRing.Desc[DescIdx + 1].Addr;
147
148 //
149 // now this descriptor can be used again to enqueue a transmit buffer
150 //
151 Dev->TxFreeStack[--Dev->TxCurPending] = (UINT16) DescIdx;
152 }
153 }
154
155 Status = EFI_SUCCESS;
156
157 Exit:
158 gBS->RestoreTPL (OldTpl);
159 return Status;
160 }
161