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 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
