[mirror_edk2.git] / OvmfPkg / VirtioScsiDxe / VirtioScsi.c

/** @file\r
\r
  This driver produces Extended SCSI Pass Thru Protocol instances for\r
  virtio-scsi devices.\r
\r
  The implementation is basic:\r
\r
  - No hotplug / hot-unplug.\r
\r
  - Although EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru() could be a good match\r
    for multiple in-flight virtio-scsi requests, we stick to synchronous\r
    requests for now.\r
\r
  - Timeouts are not supported for EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru().\r
\r
  - Only one channel is supported. (At the time of this writing, host-side\r
    virtio-scsi supports a single channel too.)\r
\r
  - Only one request queue is used (for the one synchronous request).\r
\r
  - The ResetChannel() and ResetTargetLun() functions of\r
    EFI_EXT_SCSI_PASS_THRU_PROTOCOL are not supported (which is allowed by the\r
    UEFI 2.3.1 Errata C specification), although\r
    VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET could be a good match. That would\r
    however require client code for the control queue, which is deemed\r
    unreasonable for now.\r
\r
  Copyright (C) 2012, Red Hat, Inc.\r
  Copyright (c) 2012 - 2018, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2017, AMD Inc, All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <IndustryStandard/VirtioScsi.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UefiLib.h>\r
#include <Library/VirtioLib.h>\r
\r
#include "VirtioScsi.h"\r
\r
/**\r
\r
  Convenience macros to read and write configuration elements of the\r
  virtio-scsi VirtIo device.\r
\r
  The following macros make it possible to specify only the "core parameters"\r
  for such accesses and to derive the rest. By the time VIRTIO_CFG_WRITE()\r
  returns, the transaction will have been completed.\r
\r
  @param[in] Dev       Pointer to the VSCSI_DEV structure.\r
\r
  @param[in] Field     A field name from VSCSI_HDR, identifying the virtio-scsi\r
                       configuration item to access.\r
\r
  @param[in] Value     (VIRTIO_CFG_WRITE() only.) The value to write to the\r
                       selected configuration item.\r
\r
  @param[out] Pointer  (VIRTIO_CFG_READ() only.) The object to receive the\r
                       value read from the configuration item. Its type must be\r
                       one of UINT8, UINT16, UINT32, UINT64.\r
\r
\r
  @return  Status codes returned by Virtio->WriteDevice() / Virtio->ReadDevice().\r
\r
**/\r
\r
#define VIRTIO_CFG_WRITE(Dev, Field, Value)  ((Dev)->VirtIo->WriteDevice (  \\r
                                                (Dev)->VirtIo,              \\r
                                                OFFSET_OF_VSCSI (Field),    \\r
                                                SIZE_OF_VSCSI (Field),      \\r
                                                (Value)                     \\r
                                                ))\r
\r
#define VIRTIO_CFG_READ(Dev, Field, Pointer)  ((Dev)->VirtIo->ReadDevice (  \\r
                                                (Dev)->VirtIo,              \\r
                                                OFFSET_OF_VSCSI (Field),    \\r
                                                SIZE_OF_VSCSI (Field),      \\r
                                                sizeof *(Pointer),          \\r
                                                (Pointer)                   \\r
                                                ))\r
\r
//\r
// UEFI Spec 2.3.1 + Errata C, 14.7 Extended SCSI Pass Thru Protocol specifies\r
// the PassThru() interface. Beside returning a status code, the function must\r
// set some fields in the EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET in/out\r
// parameter on return. The following is a full list of those fields, for\r
// easier validation of PopulateRequest(), ParseResponse(), and\r
// ReportHostAdapterError() below.\r
//\r
// - InTransferLength\r
// - OutTransferLength\r
// - HostAdapterStatus\r
// - TargetStatus\r
// - SenseDataLength\r
// - SenseData\r
//\r
// On any return from the PassThru() interface, these fields must be set,\r
// except if the returned status code is explicitly exempt. (Actually the\r
// implementation here conservatively sets these fields even in case not all\r
// of them would be required by the specification.)\r
//\r
\r
/**\r
\r
  Populate a virtio-scsi request from the Extended SCSI Pass Thru Protocol\r
  packet.\r
\r
  The caller is responsible for pre-zeroing the virtio-scsi request. The\r
  Extended SCSI Pass Thru Protocol packet is modified, to be forwarded outwards\r
  by VirtioScsiPassThru(), if invalid or unsupported parameters are detected.\r
\r
  @param[in] Dev          The virtio-scsi host device the packet targets.\r
\r
  @param[in] Target       The SCSI target controlled by the virtio-scsi host\r
                          device.\r
\r
  @param[in] Lun          The Logical Unit Number under the SCSI target.\r
\r
  @param[in out] Packet   The Extended SCSI Pass Thru Protocol packet the\r
                          function translates to a virtio-scsi request. On\r
                          failure this parameter relays error contents.\r
\r
  @param[out]    Request  The pre-zeroed virtio-scsi request to populate. This\r
                          parameter is volatile-qualified because we expect the\r
                          caller to append it to a virtio ring, thus\r
                          assignments to Request must be visible when the\r
                          function returns.\r
\r
\r
  @retval EFI_SUCCESS  The Extended SCSI Pass Thru Protocol packet was valid,\r
                       Request has been populated.\r
\r
  @return              Otherwise, invalid or unsupported parameters were\r
                       detected. Status codes are meant for direct forwarding\r
                       by the EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru()\r
                       implementation.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
PopulateRequest (\r
  IN     CONST    VSCSI_DEV                                   *Dev,\r
  IN              UINT16                                      Target,\r
  IN              UINT64                                      Lun,\r
  IN OUT          EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET  *Packet,\r
  OUT    volatile VIRTIO_SCSI_REQ                             *Request\r
  )\r
{\r
  UINTN  Idx;\r
\r
  if (\r
      //\r
      // bidirectional transfer was requested, but the host doesn't support it\r
      //\r
      ((Packet->InTransferLength > 0) && (Packet->OutTransferLength > 0) &&\r
       !Dev->InOutSupported) ||\r
\r
      //\r
      // a target / LUN was addressed that's impossible to encode for the host\r
      //\r
      (Target > 0xFF) || (Lun >= 0x4000) ||\r
\r
      //\r
      // Command Descriptor Block bigger than VIRTIO_SCSI_CDB_SIZE\r
      //\r
      (Packet->CdbLength > VIRTIO_SCSI_CDB_SIZE) ||\r
\r
      //\r
      // From virtio-0.9.5, 2.3.2 Descriptor Table:\r
      // "no descriptor chain may be more than 2^32 bytes long in total".\r
      //\r
      ((UINT64)Packet->InTransferLength + Packet->OutTransferLength > SIZE_1GB)\r
      )\r
  {\r
    //\r
    // this error code doesn't require updates to the Packet output fields\r
    //\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  if (\r
      //\r
      // addressed invalid device\r
      //\r
      (Target > Dev->MaxTarget) || (Lun > Dev->MaxLun) ||\r
\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
      //\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
      //\r
      // trying to send, but source pointer is NULL, or contradicting transfer\r
      // 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
  // Catch oversized requests eagerly. If this condition evaluates to false,\r
  // then the combined size of a bidirectional request will not exceed the\r
  // virtio-scsi device's transfer limit either.\r
  //\r
  if ((ALIGN_VALUE (Packet->OutTransferLength, 512) / 512\r
       > Dev->MaxSectors / 2) ||\r
      (ALIGN_VALUE (Packet->InTransferLength, 512) / 512\r
       > Dev->MaxSectors / 2))\r
  {\r
    Packet->InTransferLength  = (Dev->MaxSectors / 2) * 512;\r
    Packet->OutTransferLength = (Dev->MaxSectors / 2) * 512;\r
    Packet->HostAdapterStatus =\r
      EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN;\r
    Packet->TargetStatus    = EFI_EXT_SCSI_STATUS_TARGET_GOOD;\r
    Packet->SenseDataLength = 0;\r
    return EFI_BAD_BUFFER_SIZE;\r
  }\r
\r
  //\r
  // target & LUN encoding: see virtio-0.9.5, Appendix I: SCSI Host Device,\r
  // Device Operation: request queues\r
  //\r
  Request->Lun[0] = 1;\r
  Request->Lun[1] = (UINT8)Target;\r
  Request->Lun[2] = (UINT8)(((UINT32)Lun >> 8) | 0x40);\r
  Request->Lun[3] = (UINT8)Lun;\r
\r
  //\r
  // CopyMem() would cast away the "volatile" qualifier before access, which is\r
  // undefined behavior (ISO C99 6.7.3p5)\r
  //\r
  for (Idx = 0; Idx < Packet->CdbLength; ++Idx) {\r
    Request->Cdb[Idx] = ((UINT8 *)Packet->Cdb)[Idx];\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
\r
  Parse the virtio-scsi device's response, translate it to an EFI status code,\r
  and update the Extended SCSI Pass Thru Protocol packet, to be returned by\r
  the EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru() implementation.\r
\r
  @param[in out] Packet  The Extended SCSI Pass Thru Protocol packet that has\r
                         been translated to a virtio-scsi request with\r
                         PopulateRequest(), and processed by the host. On\r
                         output this parameter is updated with response or\r
                         error contents.\r
\r
  @param[in] Response    The virtio-scsi response structure to parse. We expect\r
                         it to come from a virtio ring, thus it is qualified\r
                         volatile.\r
\r
\r
  @return  PassThru() status codes mandated by UEFI Spec 2.3.1 + Errata C, 14.7\r
           Extended SCSI Pass Thru Protocol.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
ParseResponse (\r
  IN OUT                EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET  *Packet,\r
  IN     CONST volatile VIRTIO_SCSI_RESP                            *Response\r
  )\r
{\r
  UINTN  ResponseSenseLen;\r
  UINTN  Idx;\r
\r
  //\r
  // return sense data (length and contents) in all cases, truncated if needed\r
  //\r
  ResponseSenseLen = MIN (Response->SenseLen, VIRTIO_SCSI_SENSE_SIZE);\r
  if (Packet->SenseDataLength > ResponseSenseLen) {\r
    Packet->SenseDataLength = (UINT8)ResponseSenseLen;\r
  }\r
\r
  for (Idx = 0; Idx < Packet->SenseDataLength; ++Idx) {\r
    ((UINT8 *)Packet->SenseData)[Idx] = Response->Sense[Idx];\r
  }\r
\r
  //\r
  // Report actual transfer lengths. The logic below covers all three\r
  // DataDirections (read, write, bidirectional).\r
  //\r
  // -+- @ 0\r
  //  |\r
  //  | write                                       ^  @ Residual (unprocessed)\r
  //  |                                             |\r
  // -+- @ OutTransferLength                       -+- @ InTransferLength\r
  //  |                                             |\r
  //  | read                                        |\r
  //  |                                             |\r
  //  V  @ OutTransferLength + InTransferLength    -+- @ 0\r
  //\r
  if (Response->Residual <= Packet->InTransferLength) {\r
    Packet->InTransferLength -= Response->Residual;\r
  } else {\r
    Packet->OutTransferLength -= Response->Residual - Packet->InTransferLength;\r
    Packet->InTransferLength   = 0;\r
  }\r
\r
  //\r
  // report target status in all cases\r
  //\r
  Packet->TargetStatus = Response->Status;\r
\r
  //\r
  // host adapter status and function return value depend on virtio-scsi\r
  // response code\r
  //\r
  switch (Response->Response) {\r
    case VIRTIO_SCSI_S_OK:\r
      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OK;\r
      return EFI_SUCCESS;\r
\r
    case VIRTIO_SCSI_S_OVERRUN:\r
      Packet->HostAdapterStatus =\r
        EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN;\r
      break;\r
\r
    case VIRTIO_SCSI_S_BAD_TARGET:\r
      //\r
      // This is non-intuitive but explicitly required by the\r
      // EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru() specification for\r
      // disconnected (but otherwise valid) target / LUN addresses.\r
      //\r
      Packet->HostAdapterStatus =\r
        EFI_EXT_SCSI_STATUS_HOST_ADAPTER_TIMEOUT_COMMAND;\r
      return EFI_TIMEOUT;\r
\r
    case VIRTIO_SCSI_S_RESET:\r
      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_BUS_RESET;\r
      break;\r
\r
    case VIRTIO_SCSI_S_BUSY:\r
      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OK;\r
      return EFI_NOT_READY;\r
\r
    //\r
    // Lump together the rest. The mapping for VIRTIO_SCSI_S_ABORTED is\r
    // intentional as well, not an oversight.\r
    //\r
    case VIRTIO_SCSI_S_ABORTED:\r
    case VIRTIO_SCSI_S_TRANSPORT_FAILURE:\r
    case VIRTIO_SCSI_S_TARGET_FAILURE:\r
    case VIRTIO_SCSI_S_NEXUS_FAILURE:\r
    case VIRTIO_SCSI_S_FAILURE:\r
    default:\r
      Packet->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OTHER;\r
  }\r
\r
  return EFI_DEVICE_ERROR;\r
}\r
\r
/**\r
\r
  The function can be used to create a fake host adapter error.\r
\r
  When VirtioScsiPassThru() is failed due to some reasons then this function\r
  can be called to construct a host adapter error.\r
\r
  @param[out] Packet  The Extended SCSI Pass Thru Protocol packet that the host\r
                      adapter error shall be placed in.\r
\r
\r
  @retval EFI_DEVICE_ERROR  The function returns this status code\r
                            unconditionally, to be propagated by\r
                            VirtioScsiPassThru().\r
\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->HostAdapterStatus = EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OTHER;\r
  Packet->TargetStatus      = EFI_EXT_SCSI_STATUS_TARGET_GOOD;\r
  Packet->SenseDataLength   = 0;\r
  return EFI_DEVICE_ERROR;\r
}\r
\r
//\r
// The next seven functions implement EFI_EXT_SCSI_PASS_THRU_PROTOCOL\r
// for the virtio-scsi HBA. Refer to UEFI Spec 2.3.1 + Errata C, sections\r
// - 14.1 SCSI Driver Model Overview,\r
// - 14.7 Extended SCSI Pass Thru Protocol.\r
//\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiPassThru (\r
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL             *This,\r
  IN     UINT8                                       *Target,\r
  IN     UINT64                                      Lun,\r
  IN OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET  *Packet,\r
  IN     EFI_EVENT                                   Event   OPTIONAL\r
  )\r
{\r
  VSCSI_DEV                  *Dev;\r
  UINT16                     TargetValue;\r
  EFI_STATUS                 Status;\r
  volatile VIRTIO_SCSI_REQ   Request;\r
  volatile VIRTIO_SCSI_RESP  *Response;\r
  VOID                       *ResponseBuffer;\r
  DESC_INDICES               Indices;\r
  VOID                       *RequestMapping;\r
  VOID                       *ResponseMapping;\r
  VOID                       *InDataMapping;\r
  VOID                       *OutDataMapping;\r
  EFI_PHYSICAL_ADDRESS       RequestDeviceAddress;\r
  EFI_PHYSICAL_ADDRESS       ResponseDeviceAddress;\r
  EFI_PHYSICAL_ADDRESS       InDataDeviceAddress;\r
  EFI_PHYSICAL_ADDRESS       OutDataDeviceAddress;\r
  VOID                       *InDataBuffer;\r
  UINTN                      InDataNumPages;\r
  BOOLEAN                    OutDataBufferIsMapped;\r
\r
  //\r
  // Set InDataMapping,OutDataMapping,InDataDeviceAddress and OutDataDeviceAddress to\r
  // suppress incorrect compiler/analyzer warnings.\r
  //\r
  InDataMapping        = NULL;\r
  OutDataMapping       = NULL;\r
  InDataDeviceAddress  = 0;\r
  OutDataDeviceAddress = 0;\r
\r
  ZeroMem ((VOID *)&Request, sizeof (Request));\r
\r
  Dev = VIRTIO_SCSI_FROM_PASS_THRU (This);\r
  CopyMem (&TargetValue, Target, sizeof TargetValue);\r
\r
  InDataBuffer          = NULL;\r
  OutDataBufferIsMapped = FALSE;\r
  InDataNumPages        = 0;\r
\r
  Status = PopulateRequest (Dev, TargetValue, Lun, Packet, &Request);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Map the virtio-scsi Request header buffer\r
  //\r
  Status = VirtioMapAllBytesInSharedBuffer (\r
             Dev->VirtIo,\r
             VirtioOperationBusMasterRead,\r
             (VOID *)&Request,\r
             sizeof Request,\r
             &RequestDeviceAddress,\r
             &RequestMapping\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return ReportHostAdapterError (Packet);\r
  }\r
\r
  //\r
  // Map the input buffer\r
  //\r
  if (Packet->InTransferLength > 0) {\r
    //\r
    // Allocate a intermediate input buffer. This is mainly to handle the\r
    // following case:\r
    //  * caller submits a bi-directional request\r
    //  * we perform the request fine\r
    //  * but we fail to unmap the "InDataMapping"\r
    //\r
    // In that case simply returning the EFI_DEVICE_ERROR is not sufficient. In\r
    // addition to the error code we also need to update Packet fields\r
    // accordingly so that we report the full loss of the incoming transfer.\r
    //\r
    // We allocate a temporary buffer and map it with BusMasterCommonBuffer. If\r
    // the Virtio request is successful then we copy the data from temporary\r
    // buffer into Packet->InDataBuffer.\r
    //\r
    InDataNumPages = EFI_SIZE_TO_PAGES ((UINTN)Packet->InTransferLength);\r
    Status         = Dev->VirtIo->AllocateSharedPages (\r
                                    Dev->VirtIo,\r
                                    InDataNumPages,\r
                                    &InDataBuffer\r
                                    );\r
    if (EFI_ERROR (Status)) {\r
      Status = ReportHostAdapterError (Packet);\r
      goto UnmapRequestBuffer;\r
    }\r
\r
    ZeroMem (InDataBuffer, Packet->InTransferLength);\r
\r
    Status = VirtioMapAllBytesInSharedBuffer (\r
               Dev->VirtIo,\r
               VirtioOperationBusMasterCommonBuffer,\r
               InDataBuffer,\r
               Packet->InTransferLength,\r
               &InDataDeviceAddress,\r
               &InDataMapping\r
               );\r
    if (EFI_ERROR (Status)) {\r
      Status = ReportHostAdapterError (Packet);\r
      goto FreeInDataBuffer;\r
    }\r
  }\r
\r
  //\r
  // Map the output buffer\r
  //\r
  if (Packet->OutTransferLength > 0) {\r
    Status = VirtioMapAllBytesInSharedBuffer (\r
               Dev->VirtIo,\r
               VirtioOperationBusMasterRead,\r
               Packet->OutDataBuffer,\r
               Packet->OutTransferLength,\r
               &OutDataDeviceAddress,\r
               &OutDataMapping\r
               );\r
    if (EFI_ERROR (Status)) {\r
      Status = ReportHostAdapterError (Packet);\r
      goto UnmapInDataBuffer;\r
    }\r
\r
    OutDataBufferIsMapped = TRUE;\r
  }\r
\r
  //\r
  // Response header is bi-direction (we preset with host status and expect\r
  // the device to update it). Allocate a response buffer which can be mapped\r
  // to access equally by both processor and device.\r
  //\r
  Status = Dev->VirtIo->AllocateSharedPages (\r
                          Dev->VirtIo,\r
                          EFI_SIZE_TO_PAGES (sizeof *Response),\r
                          &ResponseBuffer\r
                          );\r
  if (EFI_ERROR (Status)) {\r
    Status = ReportHostAdapterError (Packet);\r
    goto UnmapOutDataBuffer;\r
  }\r
\r
  Response = ResponseBuffer;\r
\r
  ZeroMem ((VOID *)Response, sizeof (*Response));\r
\r
  //\r
  // preset a host status for ourselves that we do not accept as success\r
  //\r
  Response->Response = VIRTIO_SCSI_S_FAILURE;\r
\r
  //\r
  // Map the response buffer with BusMasterCommonBuffer so that response\r
  // buffer can be accessed by both host and device.\r
  //\r
  Status = VirtioMapAllBytesInSharedBuffer (\r
             Dev->VirtIo,\r
             VirtioOperationBusMasterCommonBuffer,\r
             ResponseBuffer,\r
             sizeof (*Response),\r
             &ResponseDeviceAddress,\r
             &ResponseMapping\r
             );\r
  if (EFI_ERROR (Status)) {\r
    Status = ReportHostAdapterError (Packet);\r
    goto FreeResponseBuffer;\r
  }\r
\r
  VirtioPrepare (&Dev->Ring, &Indices);\r
\r
  //\r
  // ensured by VirtioScsiInit() -- this predicate, in combination with the\r
  // lock-step progress, ensures we don't have to track free descriptors.\r
  //\r
  ASSERT (Dev->Ring.QueueSize >= 4);\r
\r
  //\r
  // enqueue Request\r
  //\r
  VirtioAppendDesc (\r
    &Dev->Ring,\r
    RequestDeviceAddress,\r
    sizeof Request,\r
    VRING_DESC_F_NEXT,\r
    &Indices\r
    );\r
\r
  //\r
  // enqueue "dataout" if any\r
  //\r
  if (Packet->OutTransferLength > 0) {\r
    VirtioAppendDesc (\r
      &Dev->Ring,\r
      OutDataDeviceAddress,\r
      Packet->OutTransferLength,\r
      VRING_DESC_F_NEXT,\r
      &Indices\r
      );\r
  }\r
\r
  //\r
  // enqueue Response, to be written by the host\r
  //\r
  VirtioAppendDesc (\r
    &Dev->Ring,\r
    ResponseDeviceAddress,\r
    sizeof *Response,\r
    VRING_DESC_F_WRITE | (Packet->InTransferLength > 0 ? VRING_DESC_F_NEXT : 0),\r
    &Indices\r
    );\r
\r
  //\r
  // enqueue "datain" if any, to be written by the host\r
  //\r
  if (Packet->InTransferLength > 0) {\r
    VirtioAppendDesc (\r
      &Dev->Ring,\r
      InDataDeviceAddress,\r
      Packet->InTransferLength,\r
      VRING_DESC_F_WRITE,\r
      &Indices\r
      );\r
  }\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 the\r
  // caller retry.\r
  //\r
  if (VirtioFlush (\r
        Dev->VirtIo,\r
        VIRTIO_SCSI_REQUEST_QUEUE,\r
        &Dev->Ring,\r
        &Indices,\r
        NULL\r
        ) != EFI_SUCCESS)\r
  {\r
    Status = ReportHostAdapterError (Packet);\r
    goto UnmapResponseBuffer;\r
  }\r
\r
  Status = ParseResponse (Packet, Response);\r
\r
  //\r
  // If virtio request was successful and it was a CPU read request then we\r
  // have used an intermediate buffer. Copy the data from intermediate buffer\r
  // to the final buffer.\r
  //\r
  if (InDataBuffer != NULL) {\r
    CopyMem (Packet->InDataBuffer, InDataBuffer, Packet->InTransferLength);\r
  }\r
\r
UnmapResponseBuffer:\r
  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, ResponseMapping);\r
\r
FreeResponseBuffer:\r
  Dev->VirtIo->FreeSharedPages (\r
                 Dev->VirtIo,\r
                 EFI_SIZE_TO_PAGES (sizeof *Response),\r
                 ResponseBuffer\r
                 );\r
\r
UnmapOutDataBuffer:\r
  if (OutDataBufferIsMapped) {\r
    Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, OutDataMapping);\r
  }\r
\r
UnmapInDataBuffer:\r
  if (InDataBuffer != NULL) {\r
    Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, InDataMapping);\r
  }\r
\r
FreeInDataBuffer:\r
  if (InDataBuffer != NULL) {\r
    Dev->VirtIo->FreeSharedPages (Dev->VirtIo, InDataNumPages, InDataBuffer);\r
  }\r
\r
UnmapRequestBuffer:\r
  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, RequestMapping);\r
\r
  return Status;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiGetNextTargetLun (\r
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This,\r
  IN OUT UINT8                            **TargetPointer,\r
  IN OUT UINT64                           *Lun\r
  )\r
{\r
  UINT8      *Target;\r
  UINTN      Idx;\r
  UINT16     LastTarget;\r
  VSCSI_DEV  *Dev;\r
\r
  //\r
  // the TargetPointer input parameter is unnecessarily a pointer-to-pointer\r
  //\r
  Target = *TargetPointer;\r
\r
  //\r
  // Search for first non-0xFF byte. If not found, return first target & LUN.\r
  //\r
  for (Idx = 0; Idx < TARGET_MAX_BYTES && Target[Idx] == 0xFF; ++Idx) {\r
  }\r
\r
  if (Idx == TARGET_MAX_BYTES) {\r
    SetMem (Target, TARGET_MAX_BYTES, 0x00);\r
    *Lun = 0;\r
    return EFI_SUCCESS;\r
  }\r
\r
  //\r
  // see the TARGET_MAX_BYTES check in "VirtioScsi.h"\r
  //\r
  CopyMem (&LastTarget, Target, sizeof LastTarget);\r
\r
  //\r
  // increment (target, LUN) pair if valid on input\r
  //\r
  Dev = VIRTIO_SCSI_FROM_PASS_THRU (This);\r
  if ((LastTarget > Dev->MaxTarget) || (*Lun > Dev->MaxLun)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (*Lun < Dev->MaxLun) {\r
    ++*Lun;\r
    return EFI_SUCCESS;\r
  }\r
\r
  if (LastTarget < Dev->MaxTarget) {\r
    *Lun = 0;\r
    ++LastTarget;\r
    CopyMem (Target, &LastTarget, sizeof LastTarget);\r
    return EFI_SUCCESS;\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiBuildDevicePath (\r
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This,\r
  IN     UINT8                            *Target,\r
  IN     UINT64                           Lun,\r
  IN OUT EFI_DEVICE_PATH_PROTOCOL         **DevicePath\r
  )\r
{\r
  UINT16            TargetValue;\r
  VSCSI_DEV         *Dev;\r
  SCSI_DEVICE_PATH  *ScsiDevicePath;\r
\r
  if (DevicePath == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  CopyMem (&TargetValue, Target, sizeof TargetValue);\r
  Dev = VIRTIO_SCSI_FROM_PASS_THRU (This);\r
  if ((TargetValue > Dev->MaxTarget) || (Lun > Dev->MaxLun) || (Lun > 0xFFFF)) {\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  ScsiDevicePath = AllocatePool (sizeof *ScsiDevicePath);\r
  if (ScsiDevicePath == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  ScsiDevicePath->Header.Type      = MESSAGING_DEVICE_PATH;\r
  ScsiDevicePath->Header.SubType   = MSG_SCSI_DP;\r
  ScsiDevicePath->Header.Length[0] = (UINT8)sizeof *ScsiDevicePath;\r
  ScsiDevicePath->Header.Length[1] = (UINT8)(sizeof *ScsiDevicePath >> 8);\r
  ScsiDevicePath->Pun              = TargetValue;\r
  ScsiDevicePath->Lun              = (UINT16)Lun;\r
\r
  *DevicePath = &ScsiDevicePath->Header;\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiGetTargetLun (\r
  IN  EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This,\r
  IN  EFI_DEVICE_PATH_PROTOCOL         *DevicePath,\r
  OUT UINT8                            **TargetPointer,\r
  OUT UINT64                           *Lun\r
  )\r
{\r
  SCSI_DEVICE_PATH  *ScsiDevicePath;\r
  VSCSI_DEV         *Dev;\r
  UINT8             *Target;\r
\r
  if ((DevicePath == NULL) || (TargetPointer == NULL) || (*TargetPointer == NULL) ||\r
      (Lun == NULL))\r
  {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if ((DevicePath->Type    != MESSAGING_DEVICE_PATH) ||\r
      (DevicePath->SubType != MSG_SCSI_DP))\r
  {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  ScsiDevicePath = (SCSI_DEVICE_PATH *)DevicePath;\r
  Dev            = VIRTIO_SCSI_FROM_PASS_THRU (This);\r
  if ((ScsiDevicePath->Pun > Dev->MaxTarget) ||\r
      (ScsiDevicePath->Lun > Dev->MaxLun))\r
  {\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  //\r
  // a) the TargetPointer input parameter is unnecessarily a pointer-to-pointer\r
  // b) see the TARGET_MAX_BYTES check in "VirtioScsi.h"\r
  // c) ScsiDevicePath->Pun is an UINT16\r
  //\r
  Target = *TargetPointer;\r
  CopyMem (Target, &ScsiDevicePath->Pun, 2);\r
  SetMem (Target + 2, TARGET_MAX_BYTES - 2, 0x00);\r
\r
  *Lun = ScsiDevicePath->Lun;\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiResetChannel (\r
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This\r
  )\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiResetTargetLun (\r
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This,\r
  IN UINT8                            *Target,\r
  IN UINT64                           Lun\r
  )\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiGetNextTarget (\r
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *This,\r
  IN OUT UINT8                        **TargetPointer\r
  )\r
{\r
  UINT8      *Target;\r
  UINTN      Idx;\r
  UINT16     LastTarget;\r
  VSCSI_DEV  *Dev;\r
\r
  //\r
  // the TargetPointer input parameter is unnecessarily a pointer-to-pointer\r
  //\r
  Target = *TargetPointer;\r
\r
  //\r
  // Search for first non-0xFF byte. If not found, return first target.\r
  //\r
  for (Idx = 0; Idx < TARGET_MAX_BYTES && Target[Idx] == 0xFF; ++Idx) {\r
  }\r
\r
  if (Idx == TARGET_MAX_BYTES) {\r
    SetMem (Target, TARGET_MAX_BYTES, 0x00);\r
    return EFI_SUCCESS;\r
  }\r
\r
  //\r
  // see the TARGET_MAX_BYTES check in "VirtioScsi.h"\r
  //\r
  CopyMem (&LastTarget, Target, sizeof LastTarget);\r
\r
  //\r
  // increment target if valid on input\r
  //\r
  Dev = VIRTIO_SCSI_FROM_PASS_THRU (This);\r
  if (LastTarget > Dev->MaxTarget) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (LastTarget < Dev->MaxTarget) {\r
    ++LastTarget;\r
    CopyMem (Target, &LastTarget, sizeof LastTarget);\r
    return EFI_SUCCESS;\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiInit (\r
  IN OUT VSCSI_DEV  *Dev\r
  )\r
{\r
  UINT8       NextDevStat;\r
  EFI_STATUS  Status;\r
  UINT64      RingBaseShift;\r
  UINT64      Features;\r
  UINT16      MaxChannel; // for validation only\r
  UINT32      NumQueues;  // for validation only\r
  UINT16      QueueSize;\r
\r
  //\r
  // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.\r
  //\r
  NextDevStat = 0;             // step 1 -- reset device\r
  Status      = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  NextDevStat |= VSTAT_ACK;    // step 2 -- acknowledge device presence\r
  Status       = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  NextDevStat |= VSTAT_DRIVER; // step 3 -- we know how to drive it\r
  Status       = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // Set Page Size - MMIO VirtIo Specific\r
  //\r
  Status = Dev->VirtIo->SetPageSize (Dev->VirtIo, EFI_PAGE_SIZE);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // step 4a -- retrieve and validate features\r
  //\r
  Status = Dev->VirtIo->GetDeviceFeatures (Dev->VirtIo, &Features);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  Dev->InOutSupported = (BOOLEAN)((Features & VIRTIO_SCSI_F_INOUT) != 0);\r
\r
  Status = VIRTIO_CFG_READ (Dev, MaxChannel, &MaxChannel);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  if (MaxChannel != 0) {\r
    //\r
    // this driver is for a single-channel virtio-scsi HBA\r
    //\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
\r
  Status = VIRTIO_CFG_READ (Dev, NumQueues, &NumQueues);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  if (NumQueues < 1) {\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
\r
  Status = VIRTIO_CFG_READ (Dev, MaxTarget, &Dev->MaxTarget);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  if (Dev->MaxTarget > PcdGet16 (PcdVirtioScsiMaxTargetLimit)) {\r
    Dev->MaxTarget = PcdGet16 (PcdVirtioScsiMaxTargetLimit);\r
  }\r
\r
  Status = VIRTIO_CFG_READ (Dev, MaxLun, &Dev->MaxLun);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  if (Dev->MaxLun > PcdGet32 (PcdVirtioScsiMaxLunLimit)) {\r
    Dev->MaxLun = PcdGet32 (PcdVirtioScsiMaxLunLimit);\r
  }\r
\r
  Status = VIRTIO_CFG_READ (Dev, MaxSectors, &Dev->MaxSectors);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  if (Dev->MaxSectors < 2) {\r
    //\r
    // We must be able to halve it for bidirectional transfers\r
    // (see EFI_BAD_BUFFER_SIZE in PopulateRequest()).\r
    //\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
\r
  Features &= VIRTIO_SCSI_F_INOUT | VIRTIO_F_VERSION_1 |\r
              VIRTIO_F_IOMMU_PLATFORM;\r
\r
  //\r
  // In virtio-1.0, feature negotiation is expected to complete before queue\r
  // discovery, and the device can also reject the selected set of features.\r
  //\r
  if (Dev->VirtIo->Revision >= VIRTIO_SPEC_REVISION (1, 0, 0)) {\r
    Status = Virtio10WriteFeatures (Dev->VirtIo, Features, &NextDevStat);\r
    if (EFI_ERROR (Status)) {\r
      goto Failed;\r
    }\r
  }\r
\r
  //\r
  // step 4b -- allocate request virtqueue\r
  //\r
  Status = Dev->VirtIo->SetQueueSel (Dev->VirtIo, VIRTIO_SCSI_REQUEST_QUEUE);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  Status = Dev->VirtIo->GetQueueNumMax (Dev->VirtIo, &QueueSize);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // VirtioScsiPassThru() uses at most four descriptors\r
  //\r
  if (QueueSize < 4) {\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
\r
  Status = VirtioRingInit (Dev->VirtIo, QueueSize, &Dev->Ring);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // If anything fails from here on, we must release the ring resources\r
  //\r
  Status = VirtioRingMap (\r
             Dev->VirtIo,\r
             &Dev->Ring,\r
             &RingBaseShift,\r
             &Dev->RingMap\r
             );\r
  if (EFI_ERROR (Status)) {\r
    goto ReleaseQueue;\r
  }\r
\r
  //\r
  // Additional steps for MMIO: align the queue appropriately, and set the\r
  // size. If anything fails from here on, we must unmap the ring resources.\r
  //\r
  Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  Status = Dev->VirtIo->SetQueueAlign (Dev->VirtIo, EFI_PAGE_SIZE);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  //\r
  // step 4c -- Report GPFN (guest-physical frame number) of queue.\r
  //\r
  Status = Dev->VirtIo->SetQueueAddress (\r
                          Dev->VirtIo,\r
                          &Dev->Ring,\r
                          RingBaseShift\r
                          );\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  //\r
  // step 5 -- Report understood features and guest-tuneables.\r
  //\r
  if (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) {\r
    Features &= ~(UINT64)(VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM);\r
    Status    = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);\r
    if (EFI_ERROR (Status)) {\r
      goto UnmapQueue;\r
    }\r
  }\r
\r
  //\r
  // We expect these maximum sizes from the host. Since they are\r
  // guest-negotiable, ask for them rather than just checking them.\r
  //\r
  Status = VIRTIO_CFG_WRITE (Dev, CdbSize, VIRTIO_SCSI_CDB_SIZE);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  Status = VIRTIO_CFG_WRITE (Dev, SenseSize, VIRTIO_SCSI_SENSE_SIZE);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  //\r
  // step 6 -- initialization complete\r
  //\r
  NextDevStat |= VSTAT_DRIVER_OK;\r
  Status       = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  //\r
  // populate the exported interface's attributes\r
  //\r
  Dev->PassThru.Mode             = &Dev->PassThruMode;\r
  Dev->PassThru.PassThru         = &VirtioScsiPassThru;\r
  Dev->PassThru.GetNextTargetLun = &VirtioScsiGetNextTargetLun;\r
  Dev->PassThru.BuildDevicePath  = &VirtioScsiBuildDevicePath;\r
  Dev->PassThru.GetTargetLun     = &VirtioScsiGetTargetLun;\r
  Dev->PassThru.ResetChannel     = &VirtioScsiResetChannel;\r
  Dev->PassThru.ResetTargetLun   = &VirtioScsiResetTargetLun;\r
  Dev->PassThru.GetNextTarget    = &VirtioScsiGetNextTarget;\r
\r
  //\r
  // AdapterId is a target for which no handle will be created during bus scan.\r
  // Prevent any conflict with real devices.\r
  //\r
  Dev->PassThruMode.AdapterId = 0xFFFFFFFF;\r
\r
  //\r
  // Set both physical and logical attributes for non-RAID SCSI channel. See\r
  // Driver Writer's Guide for UEFI 2.3.1 v1.01, 20.1.5 Implementing Extended\r
  // SCSI Pass Thru Protocol.\r
  //\r
  Dev->PassThruMode.Attributes = EFI_EXT_SCSI_PASS_THRU_ATTRIBUTES_PHYSICAL |\r
                                 EFI_EXT_SCSI_PASS_THRU_ATTRIBUTES_LOGICAL;\r
\r
  //\r
  // no restriction on transfer buffer alignment\r
  //\r
  Dev->PassThruMode.IoAlign = 0;\r
\r
  return EFI_SUCCESS;\r
\r
UnmapQueue:\r
  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);\r
\r
ReleaseQueue:\r
  VirtioRingUninit (Dev->VirtIo, &Dev->Ring);\r
\r
Failed:\r
  //\r
  // Notify the host about our failure to setup: virtio-0.9.5, 2.2.2.1 Device\r
  // Status. VirtIo access failure here should not mask the original error.\r
  //\r
  NextDevStat |= VSTAT_FAILED;\r
  Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);\r
\r
  Dev->InOutSupported = FALSE;\r
  Dev->MaxTarget      = 0;\r
  Dev->MaxLun         = 0;\r
  Dev->MaxSectors     = 0;\r
\r
  return Status; // reached only via Failed above\r
}\r
\r
STATIC\r
VOID\r
EFIAPI\r
VirtioScsiUninit (\r
  IN OUT VSCSI_DEV  *Dev\r
  )\r
{\r
  //\r
  // Reset the virtual device -- see virtio-0.9.5, 2.2.2.1 Device Status. When\r
  // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from\r
  // the old comms area.\r
  //\r
  Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);\r
\r
  Dev->InOutSupported = FALSE;\r
  Dev->MaxTarget      = 0;\r
  Dev->MaxLun         = 0;\r
  Dev->MaxSectors     = 0;\r
\r
  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);\r
  VirtioRingUninit (Dev->VirtIo, &Dev->Ring);\r
\r
  SetMem (&Dev->PassThru, sizeof Dev->PassThru, 0x00);\r
  SetMem (&Dev->PassThruMode, sizeof Dev->PassThruMode, 0x00);\r
}\r
\r
//\r
// Event notification function enqueued by ExitBootServices().\r
//\r
\r
STATIC\r
VOID\r
EFIAPI\r
VirtioScsiExitBoot (\r
  IN  EFI_EVENT  Event,\r
  IN  VOID       *Context\r
  )\r
{\r
  VSCSI_DEV  *Dev;\r
\r
  DEBUG ((DEBUG_VERBOSE, "%a: Context=0x%p\n", __FUNCTION__, Context));\r
  //\r
  // Reset the device. This causes the hypervisor to forget about the virtio\r
  // ring.\r
  //\r
  // We allocated said ring in EfiBootServicesData type memory, and code\r
  // executing after ExitBootServices() is permitted to overwrite it.\r
  //\r
  Dev = Context;\r
  Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);\r
}\r
\r
//\r
// Probe, start and stop functions of this driver, called by the DXE core for\r
// specific devices.\r
//\r
// The following specifications document these interfaces:\r
// - Driver Writer's Guide for UEFI 2.3.1 v1.01, 9 Driver Binding Protocol\r
// - UEFI Spec 2.3.1 + Errata C, 10.1 EFI Driver Binding Protocol\r
//\r
// The implementation follows:\r
// - Driver Writer's Guide for UEFI 2.3.1 v1.01\r
//   - 5.1.3.4 OpenProtocol() and CloseProtocol()\r
// - UEFI Spec 2.3.1 + Errata C\r
//   -  6.3 Protocol Handler Services\r
//\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiDriverBindingSupported (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   DeviceHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath\r
  )\r
{\r
  EFI_STATUS              Status;\r
  VIRTIO_DEVICE_PROTOCOL  *VirtIo;\r
\r
  //\r
  // Attempt to open the device with the VirtIo set of interfaces. On success,\r
  // the protocol is "instantiated" for the VirtIo device. Covers duplicate open\r
  // attempts (EFI_ALREADY_STARTED).\r
  //\r
  Status = gBS->OpenProtocol (\r
                  DeviceHandle,               // candidate device\r
                  &gVirtioDeviceProtocolGuid, // for generic VirtIo access\r
                  (VOID **)&VirtIo,           // handle to instantiate\r
                  This->DriverBindingHandle,  // requestor driver identity\r
                  DeviceHandle,               // ControllerHandle, according to\r
                                              // the UEFI Driver Model\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER // get exclusive VirtIo access to\r
                                              // the device; to be released\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  if (VirtIo->SubSystemDeviceId != VIRTIO_SUBSYSTEM_SCSI_HOST) {\r
    Status = EFI_UNSUPPORTED;\r
  }\r
\r
  //\r
  // We needed VirtIo access only transitorily, to see whether we support the\r
  // device or not.\r
  //\r
  gBS->CloseProtocol (\r
         DeviceHandle,\r
         &gVirtioDeviceProtocolGuid,\r
         This->DriverBindingHandle,\r
         DeviceHandle\r
         );\r
  return Status;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiDriverBindingStart (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   DeviceHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath\r
  )\r
{\r
  VSCSI_DEV   *Dev;\r
  EFI_STATUS  Status;\r
\r
  Dev = (VSCSI_DEV *)AllocateZeroPool (sizeof *Dev);\r
  if (Dev == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  Status = gBS->OpenProtocol (\r
                  DeviceHandle,\r
                  &gVirtioDeviceProtocolGuid,\r
                  (VOID **)&Dev->VirtIo,\r
                  This->DriverBindingHandle,\r
                  DeviceHandle,\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    goto FreeVirtioScsi;\r
  }\r
\r
  //\r
  // VirtIo access granted, configure virtio-scsi device.\r
  //\r
  Status = VirtioScsiInit (Dev);\r
  if (EFI_ERROR (Status)) {\r
    goto CloseVirtIo;\r
  }\r
\r
  Status = gBS->CreateEvent (\r
                  EVT_SIGNAL_EXIT_BOOT_SERVICES,\r
                  TPL_CALLBACK,\r
                  &VirtioScsiExitBoot,\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\r
  // interface.\r
  //\r
  Dev->Signature = VSCSI_SIG;\r
  Status         = gBS->InstallProtocolInterface (\r
                          &DeviceHandle,\r
                          &gEfiExtScsiPassThruProtocolGuid,\r
                          EFI_NATIVE_INTERFACE,\r
                          &Dev->PassThru\r
                          );\r
  if (EFI_ERROR (Status)) {\r
    goto CloseExitBoot;\r
  }\r
\r
  return EFI_SUCCESS;\r
\r
CloseExitBoot:\r
  gBS->CloseEvent (Dev->ExitBoot);\r
\r
UninitDev:\r
  VirtioScsiUninit (Dev);\r
\r
CloseVirtIo:\r
  gBS->CloseProtocol (\r
         DeviceHandle,\r
         &gVirtioDeviceProtocolGuid,\r
         This->DriverBindingHandle,\r
         DeviceHandle\r
         );\r
\r
FreeVirtioScsi:\r
  FreePool (Dev);\r
\r
  return Status;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiDriverBindingStop (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   DeviceHandle,\r
  IN UINTN                        NumberOfChildren,\r
  IN EFI_HANDLE                   *ChildHandleBuffer\r
  )\r
{\r
  EFI_STATUS                       Status;\r
  EFI_EXT_SCSI_PASS_THRU_PROTOCOL  *PassThru;\r
  VSCSI_DEV                        *Dev;\r
\r
  Status = gBS->OpenProtocol (\r
                  DeviceHandle,                     // candidate device\r
                  &gEfiExtScsiPassThruProtocolGuid, // retrieve the SCSI iface\r
                  (VOID **)&PassThru,               // target pointer\r
                  This->DriverBindingHandle,        // requestor driver ident.\r
                  DeviceHandle,                     // lookup req. for dev.\r
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL    // lookup only, no new ref.\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Dev = VIRTIO_SCSI_FROM_PASS_THRU (PassThru);\r
\r
  //\r
  // Handle Stop() requests for in-use driver instances gracefully.\r
  //\r
  Status = gBS->UninstallProtocolInterface (\r
                  DeviceHandle,\r
                  &gEfiExtScsiPassThruProtocolGuid,\r
                  &Dev->PassThru\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  gBS->CloseEvent (Dev->ExitBoot);\r
\r
  VirtioScsiUninit (Dev);\r
\r
  gBS->CloseProtocol (\r
         DeviceHandle,\r
         &gVirtioDeviceProtocolGuid,\r
         This->DriverBindingHandle,\r
         DeviceHandle\r
         );\r
\r
  FreePool (Dev);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
//\r
// The static object that groups the Supported() (ie. probe), Start() and\r
// Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata\r
// C, 10.1 EFI Driver Binding Protocol.\r
//\r
STATIC EFI_DRIVER_BINDING_PROTOCOL  gDriverBinding = {\r
  &VirtioScsiDriverBindingSupported,\r
  &VirtioScsiDriverBindingStart,\r
  &VirtioScsiDriverBindingStop,\r
  0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers\r
  NULL, // ImageHandle, to be overwritten by\r
        // EfiLibInstallDriverBindingComponentName2() in VirtioScsiEntryPoint()\r
  NULL  // DriverBindingHandle, ditto\r
};\r
\r
//\r
// The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and\r
// EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name\r
// in English, for display on standard console devices. This is recommended for\r
// UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's\r
// Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names.\r
//\r
// Device type names ("Virtio SCSI Host Device") are not formatted because the\r
// driver supports only that device type. Therefore the driver name suffices\r
// for unambiguous identification.\r
//\r
\r
STATIC\r
EFI_UNICODE_STRING_TABLE  mDriverNameTable[] = {\r
  { "eng;en", L"Virtio SCSI Host Driver" },\r
  { NULL,     NULL                       }\r
};\r
\r
STATIC\r
EFI_COMPONENT_NAME_PROTOCOL  gComponentName;\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiGetDriverName (\r
  IN  EFI_COMPONENT_NAME_PROTOCOL  *This,\r
  IN  CHAR8                        *Language,\r
  OUT CHAR16                       **DriverName\r
  )\r
{\r
  return LookupUnicodeString2 (\r
           Language,\r
           This->SupportedLanguages,\r
           mDriverNameTable,\r
           DriverName,\r
           (BOOLEAN)(This == &gComponentName) // Iso639Language\r
           );\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiGetDeviceName (\r
  IN  EFI_COMPONENT_NAME_PROTOCOL  *This,\r
  IN  EFI_HANDLE                   DeviceHandle,\r
  IN  EFI_HANDLE                   ChildHandle,\r
  IN  CHAR8                        *Language,\r
  OUT CHAR16                       **ControllerName\r
  )\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
STATIC\r
EFI_COMPONENT_NAME_PROTOCOL  gComponentName = {\r
  &VirtioScsiGetDriverName,\r
  &VirtioScsiGetDeviceName,\r
  "eng" // SupportedLanguages, ISO 639-2 language codes\r
};\r
\r
STATIC\r
EFI_COMPONENT_NAME2_PROTOCOL  gComponentName2 = {\r
  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME)&VirtioScsiGetDriverName,\r
  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME)&VirtioScsiGetDeviceName,\r
  "en" // SupportedLanguages, RFC 4646 language codes\r
};\r
\r
//\r
// Entry point of this driver.\r
//\r
EFI_STATUS\r
EFIAPI\r
VirtioScsiEntryPoint (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  return EfiLibInstallDriverBindingComponentName2 (\r
           ImageHandle,\r
           SystemTable,\r
           &gDriverBinding,\r
           ImageHandle,\r
           &gComponentName,\r
           &gComponentName2\r
           );\r
}\r