Ovmf/Xen: add Xen PV console SerialPortLib driver

This implements a SerialPortLib instance that wires up to the
PV console ring used by domU guests. Also imports the required
upstream Xen io/console.h header.

Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16976 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 191 insertions, 0 deletions

diff --git a/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
new file mode 100644
index 0000000000..98022354cf
--- /dev/null
+++ b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
@@ -0,0 +1,156 @@
+/** @file

+  Xen console SerialPortLib instance

+

+  Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>

+

+  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 <Base.h>

+#include <Uefi/UefiBaseType.h>

+

+#include <Library/BaseLib.h>

+#include <Library/SerialPortLib.h>

+#include <Library/XenHypercallLib.h>

+

+#include <IndustryStandard/Xen/io/console.h>

+#include <IndustryStandard/Xen/hvm/params.h>

+#include <IndustryStandard/Xen/event_channel.h>

+

+//

+// The code below expects these global variables to be mutable, even in the case

+// that we have been incorporated into SEC or PEIM phase modules (which is

+// allowed by our INF description). While this is a dangerous assumption to make

+// in general, it is actually fine for the Xen domU (guest) environment that

+// this module is intended for, as UEFI always executes from DRAM in that case.

+//

+STATIC evtchn_send_t              mXenConsoleEventChain;

+STATIC struct xencons_interface   *mXenConsoleInterface;

+

+RETURN_STATUS

+EFIAPI

+SerialPortInitialize (

+  VOID

+  )

+{

+  if (!mXenConsoleInterface) {

+    mXenConsoleEventChain.port = (UINT32)XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_EVTCHN);

+    mXenConsoleInterface = (struct xencons_interface *)(UINTN)

+      (XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_PFN) << EFI_PAGE_SHIFT);

+

+    //

+    // No point in ASSERT'ing here as we won't be seeing the output

+    //

+  }

+  return RETURN_SUCCESS;

+}

+

+/**

+  Write data to serial device.

+

+  @param  Buffer           Point of data buffer which need to be written.

+  @param  NumberOfBytes    Number of output bytes which are cached in Buffer.

+

+  @retval 0                Write data failed.

+  @retval !0               Actual number of bytes written to serial device.

+

+**/

+UINTN

+EFIAPI

+SerialPortWrite (

+  IN UINT8     *Buffer,

+  IN UINTN     NumberOfBytes

+  )

+{

+  XENCONS_RING_IDX  Consumer, Producer;

+  UINTN             Sent;

+

+  if (!mXenConsoleInterface) {

+    return 0;

+  }

+

+  Consumer = mXenConsoleInterface->out_cons;

+  Producer = mXenConsoleInterface->out_prod;

+

+  MemoryFence ();

+

+  Sent = 0;

+  while (Sent < NumberOfBytes && ((Producer - Consumer) < sizeof (mXenConsoleInterface->out)))

+    mXenConsoleInterface->out[MASK_XENCONS_IDX(Producer++, mXenConsoleInterface->out)] = Buffer[Sent++];

+

+  MemoryFence ();

+

+  mXenConsoleInterface->out_prod = Producer;

+

+  if (Sent > 0) {

+    XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);

+  }

+

+  return Sent;

+}

+

+/**

+  Read data from serial device and save the data in buffer.

+

+  @param  Buffer           Point of data buffer which need to be written.

+  @param  NumberOfBytes    Size of Buffer[].

+

+  @retval 0                Read data failed.

+  @retval !0               Actual number of bytes read from serial device.

+

+**/

+UINTN

+EFIAPI

+SerialPortRead (

+  OUT UINT8     *Buffer,

+  IN  UINTN     NumberOfBytes

+)

+{

+  XENCONS_RING_IDX  Consumer, Producer;

+  UINTN             Received;

+

+  if (!mXenConsoleInterface) {

+    return 0;

+  }

+

+  Consumer = mXenConsoleInterface->in_cons;

+  Producer = mXenConsoleInterface->in_prod;

+

+  MemoryFence ();

+

+  Received = 0;

+  while (Received < NumberOfBytes && Consumer < Producer)

+     Buffer[Received++] = mXenConsoleInterface->in[MASK_XENCONS_IDX(Consumer++, mXenConsoleInterface->in)];

+

+  MemoryFence ();

+

+  mXenConsoleInterface->in_cons = Consumer;

+

+  XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);

+

+  return Received;

+}

+

+/**

+  Check to see if any data is available to be read from the debug device.

+

+  @retval TRUE       At least one byte of data is available to be read

+  @retval FALSE      No data is available to be read

+

+**/

+BOOLEAN

+EFIAPI

+SerialPortPoll (

+  VOID

+  )

+{

+  return mXenConsoleInterface &&

+    mXenConsoleInterface->in_cons != mXenConsoleInterface->in_prod;

+}

diff --git a/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.inf b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.inf
new file mode 100644
index 0000000000..8a7411558f
--- /dev/null
+++ b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.inf
@@ -0,0 +1,35 @@
+#/** @file

+#

+#  Component description file for XenConsoleSerialPortLib module

+#

+#  Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>

+#

+#  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.

+#

+#**/

+

+[Defines]

+  INF_VERSION                    = 0x00010005

+  BASE_NAME                      = XenConsoleSerialPortLib

+  FILE_GUID                      = 401406DD-BCAC-4B91-9F4E-72A7FEBE4762

+  MODULE_TYPE                    = BASE

+  VERSION_STRING                 = 1.0

+  LIBRARY_CLASS                  = SerialPortLib

+  CONSTRUCTOR                    = SerialPortInitialize

+

+[Sources.common]

+  XenConsoleSerialPortLib.c

+

+[LibraryClasses]

+  BaseLib

+  XenHypercallLib

+

+[Packages]

+  MdePkg/MdePkg.dec

+  OvmfPkg/OvmfPkg.dec