]> git.proxmox.com Git - mirror_edk2.git/blobdiff - OvmfPkg/PvScsiDxe/PvScsi.c
OvmfPkg/PvScsiDxe: Refactor setup of rings to separate function
[mirror_edk2.git] / OvmfPkg / PvScsiDxe / PvScsi.c
index 76fc1eb910f29db8d29a5a33d2fc679b5842dbdb..843534ebf71103fee18381a96be17cca48f746e9 100644 (file)
 \r
 #include <IndustryStandard/Pci.h>\r
 #include <IndustryStandard/PvScsi.h>\r
+#include <Library/BaseLib.h>\r
 #include <Library/BaseMemoryLib.h>\r
 #include <Library/MemoryAllocationLib.h>\r
 #include <Library/UefiBootServicesTableLib.h>\r
 #include <Library/UefiLib.h>\r
 #include <Protocol/PciIo.h>\r
+#include <Protocol/PciRootBridgeIo.h>\r
 #include <Uefi/UefiSpec.h>\r
 \r
 #include "PvScsi.h"\r
 // Ext SCSI Pass Thru utilities\r
 //\r
 \r
+/**\r
+  Reads a 32-bit value into BAR0 using MMIO\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PvScsiMmioRead32 (\r
+  IN CONST PVSCSI_DEV   *Dev,\r
+  IN UINT64             Offset,\r
+  OUT UINT32            *Value\r
+  )\r
+{\r
+  return Dev->PciIo->Mem.Read (\r
+                           Dev->PciIo,\r
+                           EfiPciIoWidthUint32,\r
+                           PCI_BAR_IDX0,\r
+                           Offset,\r
+                           1,   // Count\r
+                           Value\r
+                           );\r
+}\r
+\r
+/**\r
+  Writes a 32-bit value into BAR0 using MMIO\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PvScsiMmioWrite32 (\r
+  IN CONST PVSCSI_DEV   *Dev,\r
+  IN UINT64             Offset,\r
+  IN UINT32             Value\r
+  )\r
+{\r
+  return Dev->PciIo->Mem.Write (\r
+                           Dev->PciIo,\r
+                           EfiPciIoWidthUint32,\r
+                           PCI_BAR_IDX0,\r
+                           Offset,\r
+                           1,   // Count\r
+                           &Value\r
+                           );\r
+}\r
+\r
+/**\r
+  Writes multiple words of data into BAR0 using MMIO\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PvScsiMmioWrite32Multiple (\r
+  IN CONST PVSCSI_DEV   *Dev,\r
+  IN UINT64             Offset,\r
+  IN UINTN              Count,\r
+  IN UINT32             *Words\r
+  )\r
+{\r
+  return Dev->PciIo->Mem.Write (\r
+                           Dev->PciIo,\r
+                           EfiPciIoWidthFifoUint32,\r
+                           PCI_BAR_IDX0,\r
+                           Offset,\r
+                           Count,\r
+                           Words\r
+                           );\r
+}\r
+\r
+/**\r
+  Send a PVSCSI command to device.\r
+\r
+  @param[in] Dev                    The pvscsi host device.\r
+  @param[in] Cmd                    The command to send to device.\r
+  @param[in] OPTIONAL DescWords     An optional command descriptor (If command\r
+                                    have a descriptor). The descriptor is\r
+                                    provided as an array of UINT32 words and\r
+                                    is must be 32-bit aligned.\r
+  @param[in] DescWordsCount         The number of words in command descriptor.\r
+                                    Caller must specify here 0 if DescWords\r
+                                    is not supplied (It is optional). In that\r
+                                    case, DescWords is ignored.\r
+\r
+  @return   Status codes returned by Dev->PciIo->Mem.Write().\r
+\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PvScsiWriteCmdDesc (\r
+  IN CONST PVSCSI_DEV   *Dev,\r
+  IN UINT32             Cmd,\r
+  IN UINT32             *DescWords      OPTIONAL,\r
+  IN UINTN              DescWordsCount\r
+  )\r
+{\r
+  EFI_STATUS Status;\r
+\r
+  if (DescWordsCount > PVSCSI_MAX_CMD_DATA_WORDS) {\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  Status = PvScsiMmioWrite32 (Dev, PvScsiRegOffsetCommand, Cmd);\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  if (DescWordsCount > 0) {\r
+    return PvScsiMmioWrite32Multiple (\r
+             Dev,\r
+             PvScsiRegOffsetCommandData,\r
+             DescWordsCount,\r
+             DescWords\r
+             );\r
+  }\r
+\r
+  return EFI_SUCCESS;\r
+}\r
+\r
+STATIC\r
+EFI_STATUS\r
+PvScsiResetAdapter (\r
+  IN CONST PVSCSI_DEV   *Dev\r
+  )\r
+{\r
+  return PvScsiWriteCmdDesc (Dev, PvScsiCmdAdapterReset, NULL, 0);\r
+}\r
+\r
+/**\r
+  Returns if PVSCSI request ring is full\r
+**/\r
+STATIC\r
+BOOLEAN\r
+PvScsiIsReqRingFull (\r
+  IN CONST PVSCSI_DEV   *Dev\r
+  )\r
+{\r
+  PVSCSI_RINGS_STATE *RingsState;\r
+  UINT32             ReqNumEntries;\r
+\r
+  RingsState = Dev->RingDesc.RingState;\r
+  ReqNumEntries = 1U << RingsState->ReqNumEntriesLog2;\r
+  return (RingsState->ReqProdIdx - RingsState->CmpConsIdx) >= ReqNumEntries;\r
+}\r
+\r
+/**\r
+  Returns pointer to current request descriptor to produce\r
+**/\r
+STATIC\r
+PVSCSI_RING_REQ_DESC *\r
+PvScsiGetCurrentRequest (\r
+  IN CONST PVSCSI_DEV   *Dev\r
+  )\r
+{\r
+  PVSCSI_RINGS_STATE *RingState;\r
+  UINT32             ReqNumEntries;\r
+\r
+  RingState = Dev->RingDesc.RingState;\r
+  ReqNumEntries = 1U << RingState->ReqNumEntriesLog2;\r
+  return Dev->RingDesc.RingReqs +\r
+         (RingState->ReqProdIdx & (ReqNumEntries - 1));\r
+}\r
+\r
+/**\r
+  Returns pointer to current completion descriptor to consume\r
+**/\r
+STATIC\r
+PVSCSI_RING_CMP_DESC *\r
+PvScsiGetCurrentResponse (\r
+  IN CONST PVSCSI_DEV   *Dev\r
+  )\r
+{\r
+  PVSCSI_RINGS_STATE *RingState;\r
+  UINT32             CmpNumEntries;\r
+\r
+  RingState = Dev->RingDesc.RingState;\r
+  CmpNumEntries = 1U << RingState->CmpNumEntriesLog2;\r
+  return Dev->RingDesc.RingCmps +\r
+         (RingState->CmpConsIdx & (CmpNumEntries - 1));\r
+}\r
+\r
+/**\r
+  Wait for device to signal completion of submitted requests\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PvScsiWaitForRequestCompletion (\r
+  IN CONST PVSCSI_DEV   *Dev\r
+  )\r
+{\r
+  EFI_STATUS Status;\r
+  UINT32     IntrStatus;\r
+\r
+  //\r
+  // Note: We don't yet support Timeout according to\r
+  // EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET.Timeout.\r
+  //\r
+  // This is consistent with some other Scsi PassThru drivers\r
+  // such as VirtioScsi.\r
+  //\r
+  for (;;) {\r
+    Status = PvScsiMmioRead32 (Dev, PvScsiRegOffsetIntrStatus, &IntrStatus);\r
+    if (EFI_ERROR (Status)) {\r
+      return Status;\r
+    }\r
+\r
+    //\r
+    // PVSCSI_INTR_CMPL_MASK is set if device completed submitted requests\r
+    //\r
+    if ((IntrStatus & PVSCSI_INTR_CMPL_MASK) != 0) {\r
+      break;\r
+    }\r
+\r
+    gBS->Stall (Dev->WaitForCmpStallInUsecs);\r
+  }\r
+\r
+  //\r
+  // Acknowledge PVSCSI_INTR_CMPL_MASK in device interrupt-status register\r
+  //\r
+  return PvScsiMmioWrite32 (\r
+           Dev,\r
+           PvScsiRegOffsetIntrStatus,\r
+           PVSCSI_INTR_CMPL_MASK\r
+           );\r
+}\r
+\r
+/**\r
+  Create a fake host adapter error\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+ReportHostAdapterError (\r
+  OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *Packet\r
+  )\r
+{\r
+  Packet->InTransferLength = 0;\r
+  Packet->OutTransferLength = 0;\r
+  Packet->SenseDataLength = 0;\r
+  Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OTHER;\r
+  Packet->TargetStatus = EFI_EXT_SCSI_STATUS_TARGET_GOOD;\r
+  return EFI_DEVICE_ERROR;\r
+}\r
+\r
+/**\r
+  Create a fake host adapter overrun error\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+ReportHostAdapterOverrunError (\r
+  OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *Packet\r
+  )\r
+{\r
+  Packet->SenseDataLength = 0;\r
+  Packet->HostAdapterStatus =\r
+            EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN;\r
+  Packet->TargetStatus = EFI_EXT_SCSI_STATUS_TARGET_GOOD;\r
+  return EFI_BAD_BUFFER_SIZE;\r
+}\r
+\r
+/**\r
+  Populate a PVSCSI request descriptor from the Extended SCSI Pass Thru\r
+  Protocol packet.\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+PopulateRequest (\r
+  IN CONST PVSCSI_DEV                               *Dev,\r
+  IN UINT8                                          *Target,\r
+  IN UINT64                                         Lun,\r
+  IN OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *Packet,\r
+  OUT PVSCSI_RING_REQ_DESC                          *Request\r
+  )\r
+{\r
+  UINT8 TargetValue;\r
+\r
+  //\r
+  // We only use first byte of target identifer\r
+  //\r
+  TargetValue = *Target;\r
+\r
+  //\r
+  // Check for unsupported requests\r
+  //\r
+  if (\r
+      //\r
+      // Bidirectional transfer was requested\r
+      //\r
+      (Packet->InTransferLength > 0 && Packet->OutTransferLength > 0) ||\r
+      (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_BIDIRECTIONAL) ||\r
+      //\r
+      // Command Descriptor Block bigger than this constant should be considered\r
+      // out-of-band. We currently don't support these CDBs.\r
+      //\r
+      (Packet->CdbLength > PVSCSI_CDB_MAX_SIZE)\r
+      ) {\r
+\r
+    //\r
+    // This error code doesn't require updates to the Packet output fields\r
+    //\r
+    return EFI_UNSUPPORTED;\r
+  }\r
+\r
+  //\r
+  // Check for invalid parameters\r
+  //\r
+  if (\r
+      //\r
+      // Addressed invalid device\r
+      //\r
+      (TargetValue > Dev->MaxTarget) || (Lun > Dev->MaxLun) ||\r
+      //\r
+      // Invalid direction (there doesn't seem to be a macro for the "no data\r
+      // transferred" "direction", eg. for TEST UNIT READY)\r
+      //\r
+      (Packet->DataDirection > EFI_EXT_SCSI_DATA_DIRECTION_BIDIRECTIONAL) ||\r
+      //\r
+      // Trying to receive, but destination pointer is NULL, or contradicting\r
+      // transfer direction\r
+      //\r
+      ((Packet->InTransferLength > 0) &&\r
+       ((Packet->InDataBuffer == NULL) ||\r
+        (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_WRITE)\r
+        )\r
+       ) ||\r
+      //\r
+      // Trying to send, but source pointer is NULL, or contradicting\r
+      // transfer direction\r
+      //\r
+      ((Packet->OutTransferLength > 0) &&\r
+       ((Packet->OutDataBuffer == NULL) ||\r
+        (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_READ)\r
+        )\r
+       )\r
+      ) {\r
+\r
+    //\r
+    // This error code doesn't require updates to the Packet output fields\r
+    //\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  //\r
+  // Check for input/output buffer too large for DMA communication buffer\r
+  //\r
+  if (Packet->InTransferLength > sizeof (Dev->DmaBuf->Data)) {\r
+    Packet->InTransferLength = sizeof (Dev->DmaBuf->Data);\r
+    return ReportHostAdapterOverrunError (Packet);\r
+  }\r
+  if (Packet->OutTransferLength > sizeof (Dev->DmaBuf->Data)) {\r
+    Packet->OutTransferLength = sizeof (Dev->DmaBuf->Data);\r
+    return ReportHostAdapterOverrunError (Packet);\r
+  }\r
+\r
+  //\r
+  // Encode PVSCSI request\r
+  //\r
+  ZeroMem (Request, sizeof (*Request));\r
+\r
+  Request->Bus = 0;\r
+  Request->Target = TargetValue;\r
+  //\r
+  // This cast is safe as PVSCSI_DEV.MaxLun is defined as UINT8\r
+  //\r
+  Request->Lun[1] = (UINT8)Lun;\r
+  Request->SenseLen = Packet->SenseDataLength;\r
+  //\r
+  // DMA communication buffer SenseData overflow is not possible\r
+  // due to Packet->SenseDataLength defined as UINT8\r
+  //\r
+  Request->SenseAddr = PVSCSI_DMA_BUF_DEV_ADDR (Dev, SenseData);\r
+  Request->CdbLen = Packet->CdbLength;\r
+  CopyMem (Request->Cdb, Packet->Cdb, Packet->CdbLength);\r
+  Request->VcpuHint = 0;\r
+  Request->Tag = PVSCSI_SIMPLE_QUEUE_TAG;\r
+  if (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_READ) {\r
+    Request->Flags = PVSCSI_FLAG_CMD_DIR_TOHOST;\r
+    Request->DataLen = Packet->InTransferLength;\r
+  } else {\r
+    Request->Flags = PVSCSI_FLAG_CMD_DIR_TODEVICE;\r
+    Request->DataLen = Packet->OutTransferLength;\r
+    CopyMem (\r
+      Dev->DmaBuf->Data,\r
+      Packet->OutDataBuffer,\r
+      Packet->OutTransferLength\r
+      );\r
+  }\r
+  Request->DataAddr = PVSCSI_DMA_BUF_DEV_ADDR (Dev, Data);\r
+\r
+  return EFI_SUCCESS;\r
+}\r
+\r
+/**\r
+  Handle the PVSCSI device response:\r
+  - Copy returned data from DMA communication buffer.\r
+  - Update fields in Extended SCSI Pass Thru Protocol packet as required.\r
+  - Translate response code to EFI status code and host adapter status.\r
+**/\r
+STATIC\r
+EFI_STATUS\r
+HandleResponse (\r
+  IN PVSCSI_DEV                                     *Dev,\r
+  IN OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *Packet,\r
+  IN CONST PVSCSI_RING_CMP_DESC                     *Response\r
+  )\r
+{\r
+  //\r
+  // Fix SenseDataLength to amount of data returned\r
+  //\r
+  if (Packet->SenseDataLength > Response->SenseLen) {\r
+    Packet->SenseDataLength = (UINT8)Response->SenseLen;\r
+  }\r
+  //\r
+  // Copy sense data from DMA communication buffer\r
+  //\r
+  CopyMem (\r
+    Packet->SenseData,\r
+    Dev->DmaBuf->SenseData,\r
+    Packet->SenseDataLength\r
+    );\r
+\r
+  //\r
+  // Copy device output from DMA communication buffer\r
+  //\r
+  if (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_READ) {\r
+    CopyMem (Packet->InDataBuffer, Dev->DmaBuf->Data, Packet->InTransferLength);\r
+  }\r
+\r
+  //\r
+  // Report target status\r
+  // (Strangely, PVSCSI interface defines Response->ScsiStatus as UINT16.\r
+  // But it should de-facto always have a value that fits UINT8. To avoid\r
+  // unexpected behavior, verify value is in UINT8 bounds before casting)\r
+  //\r
+  ASSERT (Response->ScsiStatus <= MAX_UINT8);\r
+  Packet->TargetStatus = (UINT8)Response->ScsiStatus;\r
+\r
+  //\r
+  // Host adapter status and function return value depend on\r
+  // device response's host status\r
+  //\r
+  switch (Response->HostStatus) {\r
+    case PvScsiBtStatSuccess:\r
+    case PvScsiBtStatLinkedCommandCompleted:\r
+    case PvScsiBtStatLinkedCommandCompletedWithFlag:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OK;\r
+      return EFI_SUCCESS;\r
+\r
+    case PvScsiBtStatDataUnderrun:\r
+      //\r
+      // Report transferred amount in underrun\r
+      //\r
+      if (Packet->DataDirection == EFI_EXT_SCSI_DATA_DIRECTION_READ) {\r
+        Packet->InTransferLength = (UINT32)Response->DataLen;\r
+      } else {\r
+        Packet->OutTransferLength = (UINT32)Response->DataLen;\r
+      }\r
+      Packet->HostAdapterStatus =\r
+                EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN;\r
+      return EFI_SUCCESS;\r
+\r
+    case PvScsiBtStatDatarun:\r
+      Packet->HostAdapterStatus =\r
+                EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN;\r
+      return EFI_SUCCESS;\r
+\r
+    case PvScsiBtStatSelTimeout:\r
+      Packet->HostAdapterStatus =\r
+                EFI_EXT_SCSI_STATUS_HOST_ADAPTER_SELECTION_TIMEOUT;\r
+      return EFI_TIMEOUT;\r
+\r
+    case PvScsiBtStatBusFree:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_BUS_FREE;\r
+      break;\r
+\r
+    case PvScsiBtStatInvPhase:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_PHASE_ERROR;\r
+      break;\r
+\r
+    case PvScsiBtStatSensFailed:\r
+      Packet->HostAdapterStatus =\r
+                EFI_EXT_SCSI_STATUS_HOST_ADAPTER_REQUEST_SENSE_FAILED;\r
+      break;\r
+\r
+    case PvScsiBtStatTagReject:\r
+    case PvScsiBtStatBadMsg:\r
+      Packet->HostAdapterStatus =\r
+          EFI_EXT_SCSI_STATUS_HOST_ADAPTER_MESSAGE_REJECT;\r
+      break;\r
+\r
+    case PvScsiBtStatBusReset:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_BUS_RESET;\r
+      break;\r
+\r
+    case PvScsiBtStatHaTimeout:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_TIMEOUT;\r
+      return EFI_TIMEOUT;\r
+\r
+    case PvScsiBtStatScsiParity:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_PARITY_ERROR;\r
+      break;\r
+\r
+    default:\r
+      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OTHER;\r
+      break;\r
+  }\r
+\r
+  return EFI_DEVICE_ERROR;\r
+}\r
+\r
 /**\r
   Check if Target argument to EXT_SCSI_PASS_THRU.GetNextTarget() and\r
   EXT_SCSI_PASS_THRU.GetNextTargetLun() is initialized\r
@@ -65,7 +570,62 @@ PvScsiPassThru (
   IN EFI_EVENT                                      Event    OPTIONAL\r
   )\r
 {\r
-  return EFI_UNSUPPORTED;\r
+  PVSCSI_DEV            *Dev;\r
+  EFI_STATUS            Status;\r
+  PVSCSI_RING_REQ_DESC *Request;\r
+  PVSCSI_RING_CMP_DESC *Response;\r
+\r
+  Dev = PVSCSI_FROM_PASS_THRU (This);\r
+\r
+  if (PvScsiIsReqRingFull (Dev)) {\r
+    return EFI_NOT_READY;\r
+  }\r
+\r
+  Request = PvScsiGetCurrentRequest (Dev);\r
+\r
+  Status = PopulateRequest (Dev, Target, Lun, Packet, Request);\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  //\r
+  // Writes to Request must be globally visible before making request\r
+  // available to device\r
+  //\r
+  MemoryFence ();\r
+  Dev->RingDesc.RingState->ReqProdIdx++;\r
+\r
+  Status = PvScsiMmioWrite32 (Dev, PvScsiRegOffsetKickRwIo, 0);\r
+  if (EFI_ERROR (Status)) {\r
+    //\r
+    // If kicking the host fails, we must fake a host adapter error.\r
+    // EFI_NOT_READY would save us the effort, but it would also suggest that\r
+    // the caller retry.\r
+    //\r
+    return ReportHostAdapterError (Packet);\r
+  }\r
+\r
+  Status = PvScsiWaitForRequestCompletion (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    //\r
+    // If waiting for request completion fails, we must fake a host adapter\r
+    // error. EFI_NOT_READY would save us the effort, but it would also suggest\r
+    // that the caller retry.\r
+    //\r
+    return ReportHostAdapterError (Packet);\r
+  }\r
+\r
+  Response = PvScsiGetCurrentResponse (Dev);\r
+  Status = HandleResponse (Dev, Packet, Response);\r
+\r
+  //\r
+  // Reads from response must complete before releasing completion entry\r
+  // to device\r
+  //\r
+  MemoryFence ();\r
+  Dev->RingDesc.RingState->CmpConsIdx++;\r
+\r
+  return Status;\r
 }\r
 \r
 STATIC\r
@@ -283,17 +843,338 @@ PvScsiGetNextTarget (
   return EFI_NOT_FOUND;\r
 }\r
 \r
+STATIC\r
+EFI_STATUS\r
+PvScsiSetPciAttributes (\r
+  IN OUT PVSCSI_DEV *Dev\r
+  )\r
+{\r
+  EFI_STATUS Status;\r
+\r
+  //\r
+  // Backup original PCI Attributes\r
+  //\r
+  Status = Dev->PciIo->Attributes (\r
+                         Dev->PciIo,\r
+                         EfiPciIoAttributeOperationGet,\r
+                         0,\r
+                         &Dev->OriginalPciAttributes\r
+                         );\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  //\r
+  // Enable MMIO-Space & Bus-Mastering\r
+  //\r
+  Status = Dev->PciIo->Attributes (\r
+                         Dev->PciIo,\r
+                         EfiPciIoAttributeOperationEnable,\r
+                         (EFI_PCI_IO_ATTRIBUTE_MEMORY |\r
+                          EFI_PCI_IO_ATTRIBUTE_BUS_MASTER),\r
+                         NULL\r
+                         );\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  //\r
+  // Signal device supports 64-bit DMA addresses\r
+  //\r
+  Status = Dev->PciIo->Attributes (\r
+                         Dev->PciIo,\r
+                         EfiPciIoAttributeOperationEnable,\r
+                         EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE,\r
+                         NULL\r
+                         );\r
+  if (EFI_ERROR (Status)) {\r
+    //\r
+    // Warn user that device will only be using 32-bit DMA addresses.\r
+    //\r
+    // Note that this does not prevent the device/driver from working\r
+    // and therefore we only warn and continue as usual.\r
+    //\r
+    DEBUG ((\r
+      DEBUG_WARN,\r
+      "%a: failed to enable 64-bit DMA addresses\n",\r
+      __FUNCTION__\r
+      ));\r
+  }\r
+\r
+  return EFI_SUCCESS;\r
+}\r
+\r
+STATIC\r
+VOID\r
+PvScsiRestorePciAttributes (\r
+  IN PVSCSI_DEV *Dev\r
+  )\r
+{\r
+  Dev->PciIo->Attributes (\r
+                Dev->PciIo,\r
+                EfiPciIoAttributeOperationSet,\r
+                Dev->OriginalPciAttributes,\r
+                NULL\r
+                );\r
+}\r
+\r
+STATIC\r
+EFI_STATUS\r
+PvScsiAllocateSharedPages (\r
+  IN PVSCSI_DEV                     *Dev,\r
+  IN UINTN                          Pages,\r
+  OUT VOID                          **HostAddress,\r
+  OUT PVSCSI_DMA_DESC               *DmaDesc\r
+  )\r
+{\r
+  EFI_STATUS Status;\r
+  UINTN      NumberOfBytes;\r
+\r
+  Status = Dev->PciIo->AllocateBuffer (\r
+                         Dev->PciIo,\r
+                         AllocateAnyPages,\r
+                         EfiBootServicesData,\r
+                         Pages,\r
+                         HostAddress,\r
+                         EFI_PCI_ATTRIBUTE_MEMORY_CACHED\r
+                         );\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  NumberOfBytes = EFI_PAGES_TO_SIZE (Pages);\r
+  Status = Dev->PciIo->Map (\r
+                         Dev->PciIo,\r
+                         EfiPciIoOperationBusMasterCommonBuffer,\r
+                         *HostAddress,\r
+                         &NumberOfBytes,\r
+                         &DmaDesc->DeviceAddress,\r
+                         &DmaDesc->Mapping\r
+                         );\r
+  if (EFI_ERROR (Status)) {\r
+    goto FreeBuffer;\r
+  }\r
+\r
+  if (NumberOfBytes != EFI_PAGES_TO_SIZE (Pages)) {\r
+    Status = EFI_OUT_OF_RESOURCES;\r
+    goto Unmap;\r
+  }\r
+\r
+  return EFI_SUCCESS;\r
+\r
+Unmap:\r
+  Dev->PciIo->Unmap (Dev->PciIo, DmaDesc->Mapping);\r
+\r
+FreeBuffer:\r
+  Dev->PciIo->FreeBuffer (Dev->PciIo, Pages, *HostAddress);\r
+\r
+  return Status;\r
+}\r
+\r
+STATIC\r
+VOID\r
+PvScsiFreeSharedPages (\r
+  IN PVSCSI_DEV                     *Dev,\r
+  IN UINTN                          Pages,\r
+  IN VOID                           *HostAddress,\r
+  IN PVSCSI_DMA_DESC                *DmaDesc\r
+  )\r
+{\r
+  Dev->PciIo->Unmap (Dev->PciIo, DmaDesc->Mapping);\r
+  Dev->PciIo->FreeBuffer (Dev->PciIo, Pages, HostAddress);\r
+}\r
+\r
+STATIC\r
+EFI_STATUS\r
+PvScsiInitRings (\r
+  IN OUT PVSCSI_DEV *Dev\r
+  )\r
+{\r
+  EFI_STATUS Status;\r
+\r
+  Status = PvScsiAllocateSharedPages (\r
+             Dev,\r
+             1,\r
+             (VOID **)&Dev->RingDesc.RingState,\r
+             &Dev->RingDesc.RingStateDmaDesc\r
+             );\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+  ZeroMem (Dev->RingDesc.RingState, EFI_PAGE_SIZE);\r
+\r
+  Status = PvScsiAllocateSharedPages (\r
+             Dev,\r
+             1,\r
+             (VOID **)&Dev->RingDesc.RingReqs,\r
+             &Dev->RingDesc.RingReqsDmaDesc\r
+             );\r
+  if (EFI_ERROR (Status)) {\r
+    goto FreeRingState;\r
+  }\r
+  ZeroMem (Dev->RingDesc.RingReqs, EFI_PAGE_SIZE);\r
+\r
+  Status = PvScsiAllocateSharedPages (\r
+             Dev,\r
+             1,\r
+             (VOID **)&Dev->RingDesc.RingCmps,\r
+             &Dev->RingDesc.RingCmpsDmaDesc\r
+             );\r
+  if (EFI_ERROR (Status)) {\r
+    goto FreeRingReqs;\r
+  }\r
+  ZeroMem (Dev->RingDesc.RingCmps, EFI_PAGE_SIZE);\r
+\r
+  return EFI_SUCCESS;\r
+\r
+FreeRingReqs:\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    1,\r
+    Dev->RingDesc.RingReqs,\r
+    &Dev->RingDesc.RingReqsDmaDesc\r
+    );\r
+\r
+FreeRingState:\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    1,\r
+    Dev->RingDesc.RingState,\r
+    &Dev->RingDesc.RingStateDmaDesc\r
+    );\r
+\r
+  return Status;\r
+}\r
+\r
+STATIC\r
+VOID\r
+PvScsiFreeRings (\r
+  IN OUT PVSCSI_DEV *Dev\r
+  )\r
+{\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    1,\r
+    Dev->RingDesc.RingCmps,\r
+    &Dev->RingDesc.RingCmpsDmaDesc\r
+    );\r
+\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    1,\r
+    Dev->RingDesc.RingReqs,\r
+    &Dev->RingDesc.RingReqsDmaDesc\r
+    );\r
+\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    1,\r
+    Dev->RingDesc.RingState,\r
+    &Dev->RingDesc.RingStateDmaDesc\r
+    );\r
+}\r
+\r
+STATIC\r
+EFI_STATUS\r
+PvScsiSetupRings (\r
+  IN OUT PVSCSI_DEV *Dev\r
+  )\r
+{\r
+  union {\r
+    PVSCSI_CMD_DESC_SETUP_RINGS Cmd;\r
+    UINT32                      Uint32;\r
+  } AlignedCmd;\r
+  PVSCSI_CMD_DESC_SETUP_RINGS *Cmd;\r
+\r
+  Cmd = &AlignedCmd.Cmd;\r
+\r
+  ZeroMem (Cmd, sizeof (*Cmd));\r
+  Cmd->ReqRingNumPages = 1;\r
+  Cmd->CmpRingNumPages = 1;\r
+  Cmd->RingsStatePPN = RShiftU64 (\r
+                         Dev->RingDesc.RingStateDmaDesc.DeviceAddress,\r
+                         EFI_PAGE_SHIFT\r
+                         );\r
+  Cmd->ReqRingPPNs[0] = RShiftU64 (\r
+                          Dev->RingDesc.RingReqsDmaDesc.DeviceAddress,\r
+                          EFI_PAGE_SHIFT\r
+                          );\r
+  Cmd->CmpRingPPNs[0] = RShiftU64 (\r
+                          Dev->RingDesc.RingCmpsDmaDesc.DeviceAddress,\r
+                          EFI_PAGE_SHIFT\r
+                          );\r
+\r
+  STATIC_ASSERT (\r
+    sizeof (*Cmd) % sizeof (UINT32) == 0,\r
+    "Cmd must be multiple of 32-bit words"\r
+    );\r
+  return PvScsiWriteCmdDesc (\r
+           Dev,\r
+           PvScsiCmdSetupRings,\r
+           (UINT32 *)Cmd,\r
+           sizeof (*Cmd) / sizeof (UINT32)\r
+           );\r
+}\r
+\r
 STATIC\r
 EFI_STATUS\r
 PvScsiInit (\r
   IN OUT PVSCSI_DEV *Dev\r
   )\r
 {\r
+  EFI_STATUS Status;\r
+\r
   //\r
   // Init configuration\r
   //\r
   Dev->MaxTarget = PcdGet8 (PcdPvScsiMaxTargetLimit);\r
   Dev->MaxLun = PcdGet8 (PcdPvScsiMaxLunLimit);\r
+  Dev->WaitForCmpStallInUsecs = PcdGet32 (PcdPvScsiWaitForCmpStallInUsecs);\r
+\r
+  //\r
+  // Set PCI Attributes\r
+  //\r
+  Status = PvScsiSetPciAttributes (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+\r
+  //\r
+  // Reset adapter\r
+  //\r
+  Status = PvScsiResetAdapter (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    goto RestorePciAttributes;\r
+  }\r
+\r
+  //\r
+  // Init PVSCSI rings\r
+  //\r
+  Status = PvScsiInitRings (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    goto RestorePciAttributes;\r
+  }\r
+\r
+  //\r
+  // Allocate DMA communication buffer\r
+  //\r
+  Status = PvScsiAllocateSharedPages (\r
+             Dev,\r
+             EFI_SIZE_TO_PAGES (sizeof (*Dev->DmaBuf)),\r
+             (VOID **)&Dev->DmaBuf,\r
+             &Dev->DmaBufDmaDesc\r
+             );\r
+  if (EFI_ERROR (Status)) {\r
+    goto FreeRings;\r
+  }\r
+\r
+  //\r
+  // Setup rings against device\r
+  //\r
+  Status = PvScsiSetupRings (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    goto FreeDmaCommBuffer;\r
+  }\r
 \r
   //\r
   // Populate the exported interface's attributes\r
@@ -325,6 +1206,22 @@ PvScsiInit (
   Dev->PassThruMode.IoAlign = 0;\r
 \r
   return EFI_SUCCESS;\r
+\r
+FreeDmaCommBuffer:\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    EFI_SIZE_TO_PAGES (sizeof (*Dev->DmaBuf)),\r
+    Dev->DmaBuf,\r
+    &Dev->DmaBufDmaDesc\r
+    );\r
+\r
+FreeRings:\r
+  PvScsiFreeRings (Dev);\r
+\r
+RestorePciAttributes:\r
+  PvScsiRestorePciAttributes (Dev);\r
+\r
+  return Status;\r
 }\r
 \r
 STATIC\r
@@ -333,7 +1230,54 @@ PvScsiUninit (
   IN OUT PVSCSI_DEV *Dev\r
   )\r
 {\r
-  // Currently nothing to do here\r
+  //\r
+  // Reset device to:\r
+  // - Make device stop processing all requests.\r
+  // - Stop device usage of the rings.\r
+  //\r
+  // This is required to safely free the DMA communication buffer\r
+  // and the rings.\r
+  //\r
+  PvScsiResetAdapter (Dev);\r
+\r
+  //\r
+  // Free DMA communication buffer\r
+  //\r
+  PvScsiFreeSharedPages (\r
+    Dev,\r
+    EFI_SIZE_TO_PAGES (sizeof (*Dev->DmaBuf)),\r
+    Dev->DmaBuf,\r
+    &Dev->DmaBufDmaDesc\r
+    );\r
+\r
+  PvScsiFreeRings (Dev);\r
+\r
+  PvScsiRestorePciAttributes (Dev);\r
+}\r
+\r
+/**\r
+  Event notification called by ExitBootServices()\r
+**/\r
+STATIC\r
+VOID\r
+EFIAPI\r
+PvScsiExitBoot (\r
+  IN  EFI_EVENT Event,\r
+  IN  VOID      *Context\r
+  )\r
+{\r
+  PVSCSI_DEV *Dev;\r
+\r
+  Dev = Context;\r
+  DEBUG ((DEBUG_VERBOSE, "%a: Context=0x%p\n", __FUNCTION__, Context));\r
+\r
+  //\r
+  // Reset the device to stop device usage of the rings.\r
+  //\r
+  // We allocated said rings in EfiBootServicesData type memory, and code\r
+  // executing after ExitBootServices() is permitted to overwrite it.\r
+  //\r
+  PvScsiResetAdapter (Dev);\r
 }\r
 \r
 //\r
@@ -412,11 +1356,34 @@ PvScsiDriverBindingStart (
     return EFI_OUT_OF_RESOURCES;\r
   }\r
 \r
-  Status = PvScsiInit (Dev);\r
+  Status = gBS->OpenProtocol (\r
+                  ControllerHandle,\r
+                  &gEfiPciIoProtocolGuid,\r
+                  (VOID **)&Dev->PciIo,\r
+                  This->DriverBindingHandle,\r
+                  ControllerHandle,\r
+                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
+                  );\r
   if (EFI_ERROR (Status)) {\r
     goto FreePvScsi;\r
   }\r
 \r
+  Status = PvScsiInit (Dev);\r
+  if (EFI_ERROR (Status)) {\r
+    goto ClosePciIo;\r
+  }\r
+\r
+  Status = gBS->CreateEvent (\r
+                  EVT_SIGNAL_EXIT_BOOT_SERVICES,\r
+                  TPL_CALLBACK,\r
+                  &PvScsiExitBoot,\r
+                  Dev,\r
+                  &Dev->ExitBoot\r
+                  );\r
+  if (EFI_ERROR (Status)) {\r
+    goto UninitDev;\r
+  }\r
+\r
   //\r
   // Setup complete, attempt to export the driver instance's PassThru interface\r
   //\r
@@ -428,14 +1395,25 @@ PvScsiDriverBindingStart (
                   &Dev->PassThru\r
                   );\r
   if (EFI_ERROR (Status)) {\r
-    goto UninitDev;\r
+    goto CloseExitBoot;\r
   }\r
 \r
   return EFI_SUCCESS;\r
 \r
+CloseExitBoot:\r
+  gBS->CloseEvent (Dev->ExitBoot);\r
+\r
 UninitDev:\r
   PvScsiUninit (Dev);\r
 \r
+ClosePciIo:\r
+  gBS->CloseProtocol (\r
+         ControllerHandle,\r
+         &gEfiPciIoProtocolGuid,\r
+         This->DriverBindingHandle,\r
+         ControllerHandle\r
+         );\r
+\r
 FreePvScsi:\r
   FreePool (Dev);\r
 \r
@@ -479,8 +1457,17 @@ PvScsiDriverBindingStop (
     return Status;\r
   }\r
 \r
+  gBS->CloseEvent (Dev->ExitBoot);\r
+\r
   PvScsiUninit (Dev);\r
 \r
+  gBS->CloseProtocol (\r
+         ControllerHandle,\r
+         &gEfiPciIoProtocolGuid,\r
+         This->DriverBindingHandle,\r
+         ControllerHandle\r
+         );\r
+\r
   FreePool (Dev);\r
 \r
   return EFI_SUCCESS;\r