[edk2-devel] [PATCH v2 06/21] DynamicTablesPkg: Set EndTag's Checksum if RdList is modified
Sami Mujawar
sami.mujawar at arm.com
Fri Oct 8 14:06:34 UTC 2021
Hi Pierre,
Thank you for this patch.
Reviewed-by: Sami Mujawar <sami.mujawar at arm.com>
Regards,
Sami Mujawar
On 07/10/2021 04:31 PM, Pierre.Gondois at arm.com wrote:
> From: Pierre Gondois <Pierre.Gondois at arm.com>
>
> ACPI 6.4, s6.4.2.9 "End Tag":
> "This checksum is generated such that adding it to the sum of all the data
> bytes will produce a zero sum."
> "If the checksum field is zero, the resource data is treated as if the
> checksum operation succeeded. Configuration proceeds normally."
>
> To avoid re-computing checksums, if a new resource data elements is
> added/removed/modified in a list of resource data elements, the AmlLib
> resets the checksum to 0.
>
> This patch also refactors the AmlAppendRdNode() function by getting the
> last Resource Data node directly instead of iterating over all the
> elements of the list of Resource Data node.
>
> Signed-off-by: Pierre Gondois <Pierre.Gondois at arm.com>
> ---
> .../Common/AmlLib/Tree/AmlNodeInterface.c | 7 ++
> .../Library/Common/AmlLib/Tree/AmlTree.c | 72 +++++++------------
> 2 files changed, 34 insertions(+), 45 deletions(-)
>
> diff --git a/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlNodeInterface.c b/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlNodeInterface.c
> index 870346c40a5d..f91bc5fd55d2 100644
> --- a/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlNodeInterface.c
> +++ b/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlNodeInterface.c
> @@ -513,6 +513,13 @@ AmlUpdateDataNode (
> ASSERT (0);
> return EFI_INVALID_PARAMETER;
> }
> +
> + Status = AmlSetRdListCheckSum (ParentNode, 0);
> + if (EFI_ERROR (Status)) {
> + ASSERT (0);
> + return Status;
> + }
> +
> break;
> }
> case EAmlNodeDataTypeFieldPkgLen:
> diff --git a/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlTree.c b/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlTree.c
> index 0931e751709e..2772e915f468 100644
> --- a/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlTree.c
> +++ b/DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlTree.c
> @@ -566,8 +566,7 @@ AmlAppendRdNode (
> )
> {
> EFI_STATUS Status;
> - AML_DATA_NODE * CurrRdNode;
> - AML_RD_HEADER RdDataType;
> + AML_DATA_NODE * LastRdNode;
>
> if (!AmlNodeCompareOpCode (BufferOpNode, AML_BUFFER_OP, 0) ||
> !IS_AML_DATA_NODE (NewRdNode) ||
> @@ -576,56 +575,39 @@ AmlAppendRdNode (
> return EFI_INVALID_PARAMETER;
> }
>
> - // Get the first Resource data node in the variable list of
> - // argument of the BufferOp node.
> - CurrRdNode = (AML_DATA_NODE*)AmlGetNextVariableArgument (
> + // To avoid re-computing checksums, if a new resource data elements is
> + // added/removed/modified in a list of resource data elements, the AmlLib
> + // resets the checksum to 0.
> + // It is possible to have only one Resource Data in a BufferOp with
> + // no EndTag, but it should not be possible to add a new Resource Data
> + // in the list in this case.
> + Status = AmlSetRdListCheckSum (BufferOpNode, 0);
> + if (EFI_ERROR (Status)) {
> + ASSERT (0);
> + return Status;
> + }
> +
> + // Get the last Resource data node in the variable list of argument of the
> + // BufferOp node. This must be an EndTag, otherwise setting the checksum
> + // would have failed.
> + LastRdNode = (AML_DATA_NODE*)AmlGetPreviousVariableArgument (
> (AML_NODE_HEADER*)BufferOpNode,
> NULL
> );
> - if ((CurrRdNode == NULL) ||
> - !IS_AML_DATA_NODE (CurrRdNode) ||
> - (CurrRdNode->DataType != EAmlNodeDataTypeResourceData)) {
> + if ((LastRdNode == NULL) ||
> + !IS_AML_DATA_NODE (LastRdNode) ||
> + (LastRdNode->DataType != EAmlNodeDataTypeResourceData)) {
> ASSERT (0);
> return EFI_INVALID_PARAMETER;
> }
>
> - // Iterate through the Resource Data nodes to find the End Tag.
> - while (TRUE) {
> - Status = AmlGetResourceDataType (CurrRdNode, &RdDataType);
> - if (EFI_ERROR (Status)) {
> - ASSERT (0);
> - return Status;
> - }
> -
> - // If the Resource Data is an End Tag,
> - // add the new node before and return.
> - if (AmlRdCompareDescId (
> - &RdDataType,
> - AML_RD_BUILD_SMALL_DESC_ID (ACPI_SMALL_END_TAG_DESCRIPTOR_NAME))) {
> - Status = AmlVarListAddBefore (
> - (AML_NODE_HEADER*)CurrRdNode,
> - (AML_NODE_HEADER*)NewRdNode)
> - ;
> - if (EFI_ERROR (Status)) {
> - ASSERT (0);
> - }
> - return Status;
> - }
> -
> - // Get the next Resource Data node.
> - // If this was the last node and no End Tag was found, return error.
> - // It is possible to have only one Resource Data in a BufferOp,
> - // but it should not be possible to add a new Resource Data in the list
> - // in this case.
> - CurrRdNode = (AML_DATA_NODE*)AmlGetSiblingVariableArgument (
> - (AML_NODE_HEADER*)CurrRdNode
> - );
> - if (!IS_AML_DATA_NODE (CurrRdNode) ||
> - (CurrRdNode->DataType != EAmlNodeDataTypeResourceData)) {
> - ASSERT (0);
> - return EFI_INVALID_PARAMETER;
> - }
> - } // while
> + // Add NewRdNode before the EndTag.
> + Status = AmlVarListAddBefore (
> + (AML_NODE_HEADER*)LastRdNode,
> + (AML_NODE_HEADER*)NewRdNode)
> + ;
> + ASSERT_EFI_ERROR (Status);
> + return Status;
> }
>
> /** Replace the fixed argument at the Index of the ParentNode with the NewNode.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#81677): https://edk2.groups.io/g/devel/message/81677
Mute This Topic: https://groups.io/mt/86148195/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list