[PATCH v1 4/4] DynamicTablesPkg: Set the Access size for the DBG2 table

["Joey Gouly" <joey.gouly@arm.com>]

The DBG2 table generator set the access size for the UART to
DWORD (4 bytes) by default. However, according to Section B
Generic UART, Arm Base System Architecture 1.0, Platform
Design Document, a Generic UART can have BYTE, WORD or DWORD
access sizes. To address this an AccessSize field has been
introduced in CM_ARM_SERIAL_PORT_INFO object.

This patch updates the DBG2 generator to setup the AccessSize
field in the Generic Address Structure (GAS) for the UART in
the DBG2 table with information provided by the platform.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
---
 DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c | 24 +++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
index d902bbc8463921624f1a6333e8d6bd84c6cb38f2..a7508d4a8834fd2038946a62de39e9cd0894bf79 100644
--- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
+++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
@@ -1,7 +1,7 @@
 /** @file
   DBG2 Table Generator
 
-  Copyright (c) 2017 - 2020, Arm Limited. All rights reserved.<BR>
+  Copyright (c) 2017 - 2021, Arm Limited. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -420,6 +420,28 @@ BuildDbg2TableEx (
   AcpiDbg2.Dbg2DeviceInfo[INDEX_DBG_PORT0].BaseAddressRegister.Address =
     SerialPortInfo->BaseAddress;
 
+  // Set the access size
+  if (SerialPortInfo->AccessSize >= EFI_ACPI_6_3_QWORD) {
+    Status = EFI_INVALID_PARAMETER;
+    DEBUG ((
+      DEBUG_ERROR,
+      "ERROR: DBG2: Access size must be <= 3 (DWORD). Status = %r\n",
+      Status
+      ));
+    goto error_handler;
+  } else if (SerialPortInfo->AccessSize == EFI_ACPI_6_3_UNDEFINED) {
+    // 0 Undefined (legacy reasons)
+    // Default to DWORD access size as the access
+    // size field was introduced at a later date
+    // and some ConfigurationManager implementations
+    // may not be providing this field data
+    AcpiDbg2.Dbg2DeviceInfo[INDEX_DBG_PORT0].BaseAddressRegister.AccessSize =
+      EFI_ACPI_6_3_DWORD;
+  } else {
+    AcpiDbg2.Dbg2DeviceInfo[INDEX_DBG_PORT0].BaseAddressRegister.AccessSize =
+      SerialPortInfo->AccessSize;
+  }
+
   // Update the serial port subtype
   AcpiDbg2.Dbg2DeviceInfo[INDEX_DBG_PORT0].Dbg2Device.PortSubtype =
     SerialPortInfo->PortSubtype;
-- 
Guid("CE165669-3EF3-493F-B85D-6190EE5B9759")