[PATCH v2 08/12] OvmfPkg/QemuFwCfgS3Lib: implement opcode APIs for Base Null instance

[Laszlo Ersek <lersek@redhat.com>]

In the Base Null instance:

- QemuFwCfgS3Enabled() returns constant FALSE. This is unique to the Base
  Null instance, and the function is already present in
  "QemuFwCfgS3Base.c".

- The QemuFwCfgS3CallWhenBootScriptReady() function must never be called
  (according to the documentation, given the above). This is also unique
  to the Base Null instance, so implement the function in
  "QemuFwCfgS3Base.c".

- Consequently, the QemuFwCfgS3ScriptWriteBytes(),
  QemuFwCfgS3ScriptReadBytes(), QemuFwCfgS3ScriptSkipBytes(), and
  QemuFwCfgS3ScriptCheckValue() functions must never be called either.
  This behavior is not unique to the Base Null instance (it will be shared
  with the PEI fw_cfg instance), so add these functions to
  "QemuFwCfgS3BasePei.c".

Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=394
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---

Notes:
    v2:
    - rename QemuFwCfgS3TransferOwnership to
      QemuFwCfgS3CallWhenBootScriptReady [Jordan]
    - rename FW_CFG_BOOT_SCRIPT_APPEND_FUNCTION to
      FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION [Jordan]
    - rename "Append" to "Callback" [Laszlo]
    - rename QemuFwCfgS3WriteBytes, QemuFwCfgS3ReadBytes,
      QemuFwCfgS3SkipBytes, and QemuFwCfgS3CheckValue to
      QemuFwCfgS3ScriptWriteBytes, QemuFwCfgS3ScriptReadBytes,
      QemuFwCfgS3ScriptSkipBytes, and QemuFwCfgS3ScriptCheckValue,
      respectively [Jordan]

 OvmfPkg/Library/QemuFwCfgS3Lib/BaseQemuFwCfgS3LibNull.inf |   4 +
 OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Base.c          |  71 ++++++
 OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3BasePei.c       | 227 ++++++++++++++++++++
 3 files changed, 302 insertions(+)

diff --git a/OvmfPkg/Library/QemuFwCfgS3Lib/BaseQemuFwCfgS3LibNull.inf b/OvmfPkg/Library/QemuFwCfgS3Lib/BaseQemuFwCfgS3LibNull.inf
index ba24a0b9d434..837fd70db6e5 100644
--- a/OvmfPkg/Library/QemuFwCfgS3Lib/BaseQemuFwCfgS3LibNull.inf
+++ b/OvmfPkg/Library/QemuFwCfgS3Lib/BaseQemuFwCfgS3LibNull.inf
@@ -33,7 +33,11 @@ [Defines]
 
 [Sources]
   QemuFwCfgS3Base.c
+  QemuFwCfgS3BasePei.c
 
 [Packages]
   MdePkg/MdePkg.dec
   OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  DebugLib
diff --git a/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Base.c b/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Base.c
index bed9bf3dfb57..7b71305d1267 100644
--- a/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Base.c
+++ b/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Base.c
@@ -16,6 +16,7 @@
   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 **/
 
+#include <Library/DebugLib.h>
 #include <Library/QemuFwCfgS3Lib.h>
 
 /**
@@ -37,3 +38,73 @@ QemuFwCfgS3Enabled (
 {
   return FALSE;
 }
+
+
+/**
+  Install the client module's FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION callback for
+  when the production of ACPI S3 Boot Script opcodes becomes possible.
+
+  Take ownership of the client-provided Context, and pass it to the callback
+  function, when the latter is invoked.
+
+  Allocate scratch space for those ACPI S3 Boot Script opcodes to work upon
+  that the client will produce in the callback function.
+
+  @param[in] Callback           FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION to invoke
+                                when the production of ACPI S3 Boot Script
+                                opcodes becomes possible. Callback() may be
+                                called immediately from
+                                QemuFwCfgS3CallWhenBootScriptReady().
+
+  @param[in,out] Context        Client-provided data structure for the
+                                Callback() callback function to consume.
+
+                                If Context points to dynamically allocated
+                                memory, then Callback() must release it.
+
+                                If Context points to dynamically allocated
+                                memory, and
+                                QemuFwCfgS3CallWhenBootScriptReady() returns
+                                successfully, then the caller of
+                                QemuFwCfgS3CallWhenBootScriptReady() must
+                                neither dereference nor even evaluate Context
+                                any longer, as ownership of the referenced area
+                                has been transferred to Callback().
+
+  @param[in] ScratchBufferSize  The size of the scratch buffer that will hold,
+                                in reserved memory, all client data read,
+                                written, and checked by the ACPI S3 Boot Script
+                                opcodes produced by Callback().
+
+  @retval RETURN_UNSUPPORTED       The library instance does not support this
+                                   function.
+
+  @retval RETURN_NOT_FOUND         The fw_cfg DMA interface to QEMU is
+                                   unavailable.
+
+  @retval RETURN_BAD_BUFFER_SIZE   ScratchBufferSize is too large.
+
+  @retval RETURN_OUT_OF_RESOURCES  Memory allocation failed.
+
+  @retval RETURN_SUCCESS           Callback() has been installed, and the
+                                   ownership of Context has been transferred.
+                                   Reserved memory has been allocated for the
+                                   scratch buffer.
+
+                                   A successful invocation of
+                                   QemuFwCfgS3CallWhenBootScriptReady() cannot
+                                   be rolled back.
+
+  @return                          Error codes from underlying functions.
+**/
+EFIAPI
+RETURN_STATUS
+QemuFwCfgS3CallWhenBootScriptReady (
+  IN     FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION *Callback,
+  IN OUT VOID                                 *Context,          OPTIONAL
+  IN     UINTN                                ScratchBufferSize
+  )
+{
+  ASSERT (FALSE);
+  return RETURN_UNSUPPORTED;
+}
diff --git a/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3BasePei.c b/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3BasePei.c
new file mode 100644
index 000000000000..674929e9d500
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3BasePei.c
@@ -0,0 +1,227 @@
+/** @file
+  Shared code for the Base Null and PEI fw_cfg instances of the QemuFwCfgS3Lib
+  class.
+
+  Copyright (C) 2017, Red Hat, Inc.
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/QemuFwCfgS3Lib.h>
+
+/**
+  Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item,
+  and transfer data to it.
+
+  The opcodes produced by QemuFwCfgS3ScriptWriteBytes() will first restore
+  NumberOfBytes bytes in ScratchBuffer in-place, in reserved memory, then write
+  them to fw_cfg using DMA.
+
+  If the operation fails during S3 resume, the boot script will hang.
+
+  This function may only be called from the client module's
+  FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to
+  QemuFwCfgS3CallWhenBootScriptReady() as Callback.
+
+  @param[in] FirmwareConfigItem  The UINT16 selector key of the firmware config
+                                 item to write, expressed as INT32. If
+                                 FirmwareConfigItem is -1, no selection is
+                                 made, the write will occur to the currently
+                                 selected item, at its currently selected
+                                 offset. Otherwise, the specified item will be
+                                 selected, and the write will occur at offset
+                                 0.
+
+  @param[in] NumberOfBytes       Size of the data to restore in ScratchBuffer,
+                                 and to write from ScratchBuffer, during S3
+                                 resume. NumberOfBytes must not exceed
+                                 ScratchBufferSize, which was passed to
+                                 QemuFwCfgS3CallWhenBootScriptReady().
+
+  @retval RETURN_SUCCESS            The opcodes were appended to the ACPI S3
+                                    Boot Script successfully. There is no way
+                                    to undo this action.
+
+  @retval RETURN_INVALID_PARAMETER  FirmwareConfigItem is invalid.
+
+  @retval RETURN_BAD_BUFFER_SIZE    NumberOfBytes is larger than
+                                    ScratchBufferSize.
+
+  @return                           Error codes from underlying functions.
+**/
+EFIAPI
+RETURN_STATUS
+QemuFwCfgS3ScriptWriteBytes (
+  IN INT32 FirmwareConfigItem,
+  IN UINTN NumberOfBytes
+  )
+{
+  ASSERT (FALSE);
+  return RETURN_UNSUPPORTED;
+}
+
+
+/**
+  Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item,
+  and transfer data from it.
+
+  The opcodes produced by QemuFwCfgS3ScriptReadBytes() will read NumberOfBytes
+  bytes from fw_cfg using DMA, storing the result in ScratchBuffer, in reserved
+  memory.
+
+  If the operation fails during S3 resume, the boot script will hang.
+
+  This function may only be called from the client module's
+  FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to
+  QemuFwCfgS3CallWhenBootScriptReady() as Callback.
+
+  @param[in] FirmwareConfigItem  The UINT16 selector key of the firmware config
+                                 item to read, expressed as INT32. If
+                                 FirmwareConfigItem is -1, no selection is
+                                 made, the read will occur from the currently
+                                 selected item, from its currently selected
+                                 offset. Otherwise, the specified item will be
+                                 selected, and the read will occur from offset
+                                 0.
+
+  @param[in] NumberOfBytes       Size of the data to read during S3 resume.
+                                 NumberOfBytes must not exceed
+                                 ScratchBufferSize, which was passed to
+                                 QemuFwCfgS3CallWhenBootScriptReady().
+
+  @retval RETURN_SUCCESS            The opcodes were appended to the ACPI S3
+                                    Boot Script successfully. There is no way
+                                    to undo this action.
+
+  @retval RETURN_INVALID_PARAMETER  FirmwareConfigItem is invalid.
+
+  @retval RETURN_BAD_BUFFER_SIZE    NumberOfBytes is larger than
+                                    ScratchBufferSize.
+
+  @return                           Error codes from underlying functions.
+**/
+EFIAPI
+RETURN_STATUS
+QemuFwCfgS3ScriptReadBytes (
+  IN INT32 FirmwareConfigItem,
+  IN UINTN NumberOfBytes
+  )
+{
+  ASSERT (FALSE);
+  return RETURN_UNSUPPORTED;
+}
+
+
+/**
+  Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item,
+  and increase its offset.
+
+  If the operation fails during S3 resume, the boot script will hang.
+
+  This function may only be called from the client module's
+  FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to
+  QemuFwCfgS3CallWhenBootScriptReady() as Callback.
+
+  @param[in] FirmwareConfigItem  The UINT16 selector key of the firmware config
+                                 item to advance the offset of, expressed as
+                                 INT32. If FirmwareConfigItem is -1, no
+                                 selection is made, and the offset for the
+                                 currently selected item is increased.
+                                 Otherwise, the specified item will be
+                                 selected, and the offset increment will occur
+                                 from offset 0.
+
+  @param[in] NumberOfBytes       The number of bytes to skip in the subject
+                                 fw_cfg item.
+
+  @retval RETURN_SUCCESS            The opcodes were appended to the ACPI S3
+                                    Boot Script successfully. There is no way
+                                    to undo this action.
+
+  @retval RETURN_INVALID_PARAMETER  FirmwareConfigItem is invalid.
+
+  @retval RETURN_BAD_BUFFER_SIZE    NumberOfBytes is too large.
+
+  @return                           Error codes from underlying functions.
+**/
+EFIAPI
+RETURN_STATUS
+QemuFwCfgS3ScriptSkipBytes (
+  IN INT32 FirmwareConfigItem,
+  IN UINTN NumberOfBytes
+  )
+{
+  ASSERT (FALSE);
+  return RETURN_UNSUPPORTED;
+}
+
+
+/**
+  Produce ACPI S3 Boot Script opcodes that check a value in ScratchBuffer.
+
+  If the check fails during S3 resume, the boot script will hang.
+
+  This function may only be called from the client module's
+  FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to
+  QemuFwCfgS3CallWhenBootScriptReady() as Callback.
+
+  @param[in] ScratchData  Pointer to the UINT8, UINT16, UINT32 or UINT64 field
+                          in ScratchBuffer that should be checked. The caller
+                          is responsible for populating the field during S3
+                          resume, by calling QemuFwCfgS3ScriptReadBytes() ahead
+                          of QemuFwCfgS3ScriptCheckValue().
+
+                          ScratchData must point into ScratchBuffer, which was
+                          allocated, and passed to Callback(), by
+                          QemuFwCfgS3CallWhenBootScriptReady().
+
+                          ScratchData must be aligned at ValueSize bytes.
+
+  @param[in] ValueSize    One of 1, 2, 4 or 8, specifying the size of the field
+                          to check.
+
+  @param[in] ValueMask    The value read from ScratchData is binarily AND-ed
+                          with ValueMask, and the result is compared against
+                          Value. If the masked data equals Value, the check
+                          passes, and the boot script can proceed. Otherwise,
+                          the check fails, and the boot script hangs.
+
+  @param[in] Value        Refer to ValueMask.
+
+  @retval RETURN_SUCCESS            The opcodes were appended to the ACPI S3
+                                    Boot Script successfully. There is no way
+                                    to undo this action.
+
+  @retval RETURN_INVALID_PARAMETER  ValueSize is invalid.
+
+  @retval RETURN_INVALID_PARAMETER  ValueMask or Value cannot be represented in
+                                    ValueSize bytes.
+
+  @retval RETURN_INVALID_PARAMETER  ScratchData is not aligned at ValueSize
+                                    bytes.
+
+  @retval RETURN_BAD_BUFFER_SIZE    The ValueSize bytes at ScratchData aren't
+                                    wholly contained in the ScratchBufferSize
+                                    bytes at ScratchBuffer.
+
+  @return                           Error codes from underlying functions.
+**/
+EFIAPI
+RETURN_STATUS
+QemuFwCfgS3ScriptCheckValue (
+  IN VOID   *ScratchData,
+  IN UINT8  ValueSize,
+  IN UINT64 ValueMask,
+  IN UINT64 Value
+  )
+{
+  ASSERT (FALSE);
+  return RETURN_UNSUPPORTED;
+}
-- 
2.9.3