Re: [PATCH v1 3/4] DynamicTablesPkg: Set the Access size for the SPCR table

["Sami Mujawar" <sami.mujawar@arm.com>]

Hi Joey,

This patch looks good to me.

Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

Regards,

Sami Mujawar

On 15/04/2021, 13:19, "Joey Gouly" <joey.gouly@arm.com> wrote:

    The SPCR 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 SPCR generator to setup the AccessSize
    field in the Generic Address Structure (GAS) for the UART in
    the SPCR table with information provided by the platform.

    Signed-off-by: Joey Gouly <joey.gouly@arm.com>
    ---
     DynamicTablesPkg/Library/Acpi/Arm/AcpiSpcrLibArm/SpcrGenerator.c | 22 +++++++++++++++++++-
     1 file changed, 21 insertions(+), 1 deletion(-)

    diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSpcrLibArm/SpcrGenerator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSpcrLibArm/SpcrGenerator.c
    index 24bb5c014607b0746c4a8bb8bd260510fbdff08b..fecfd6bbabd63698f5f45f6bfbd494f25cf0faeb 100644
    --- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSpcrLibArm/SpcrGenerator.c
    +++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSpcrLibArm/SpcrGenerator.c
    @@ -1,7 +1,7 @@
     /** @file
       SPCR 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

    @@ -313,6 +313,26 @@ BuildSpcrTableEx (
       // Update the base address
       AcpiSpcr.BaseAddress.Address = SerialPortInfo->BaseAddress;

    +  // Set the access size
    +  if (SerialPortInfo->AccessSize >= EFI_ACPI_6_3_QWORD) {
    +    Status = EFI_INVALID_PARAMETER;
    +    DEBUG ((
    +      DEBUG_ERROR,
    +      "ERROR: SPCR: 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
    +    AcpiSpcr.BaseAddress.AccessSize = EFI_ACPI_6_3_DWORD;
    +  } else {
    +    AcpiSpcr.BaseAddress.AccessSize = SerialPortInfo->AccessSize;
    +  }
    +
       // Update the UART interrupt
       AcpiSpcr.GlobalSystemInterrupt = SerialPortInfo->Interrupt;

    -- 
    Guid("CE165669-3EF3-493F-B85D-6190EE5B9759")