/** @file
Append an ACPI S3 Boot Script fragment from the QEMU_LOADER_WRITE_POINTER
commands of QEMU's fully processed table linker/loader script.
Copyright (C) 2017, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h> // CpuDeadLoop()
#include <Library/DebugLib.h> // DEBUG()
#include <Library/MemoryAllocationLib.h> // AllocatePool()
#include <Library/QemuFwCfgS3Lib.h> // QemuFwCfgS3ScriptSkipBytes()
#include "AcpiPlatform.h"
//
// Condensed structure for capturing the fw_cfg operations -- select, skip,
// write -- inherent in executing a QEMU_LOADER_WRITE_POINTER command.
//
typedef struct {
UINT16 PointerItem; // resolved from QEMU_LOADER_WRITE_POINTER.PointerFile
UINT8 PointerSize; // copied as-is from QEMU_LOADER_WRITE_POINTER
UINT32 PointerOffset; // copied as-is from QEMU_LOADER_WRITE_POINTER
UINT64 PointerValue; // resolved from QEMU_LOADER_WRITE_POINTER.PointeeFile
// and QEMU_LOADER_WRITE_POINTER.PointeeOffset
} CONDENSED_WRITE_POINTER;
//
// Context structure to accumulate CONDENSED_WRITE_POINTER objects from
// QEMU_LOADER_WRITE_POINTER commands.
//
// Any pointers in this structure own the pointed-to objects; that is, when the
// context structure is released, all pointed-to objects must be released too.
//
struct S3_CONTEXT {
CONDENSED_WRITE_POINTER *WritePointers; // one array element per processed
// QEMU_LOADER_WRITE_POINTER
// command
UINTN Allocated; // number of elements allocated for
// WritePointers
UINTN Used; // number of elements populated in
// WritePointers
};
//
// Scratch buffer, allocated in EfiReservedMemoryType type memory, for the ACPI
// S3 Boot Script opcodes to work on.
//
#pragma pack (1)
typedef union {
UINT64 PointerValue; // filled in from CONDENSED_WRITE_POINTER.PointerValue
} SCRATCH_BUFFER;
#pragma pack ()
/**
Allocate an S3_CONTEXT object.
@param[out] S3Context The allocated S3_CONTEXT object is returned
through this parameter.
@param[in] WritePointerCount Number of CONDENSED_WRITE_POINTER elements to
allocate room for. WritePointerCount must be
positive.
@retval EFI_SUCCESS Allocation successful.
@retval EFI_OUT_OF_RESOURCES Out of memory.
@retval EFI_INVALID_PARAMETER WritePointerCount is zero.
**/
EFI_STATUS
AllocateS3Context (
OUT S3_CONTEXT **S3Context,
IN UINTN WritePointerCount
)
{
EFI_STATUS Status;
S3_CONTEXT *Context;
if (WritePointerCount == 0) {
return EFI_INVALID_PARAMETER;
}
Context = AllocateZeroPool (sizeof *Context);
if (Context == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Context->WritePointers = AllocatePool (
WritePointerCount *
sizeof *Context->WritePointers
);
if (Context->WritePointers == NULL) {
Status = EFI_OUT_OF_RESOURCES;
goto FreeContext;
}
Context->Allocated = WritePointerCount;
*S3Context = Context;
return EFI_SUCCESS;
FreeContext:
FreePool (Context);
return Status;
}
/**
Release an S3_CONTEXT object.
@param[in] S3Context The object to release.
**/
VOID
ReleaseS3Context (
IN S3_CONTEXT *S3Context
)
{
FreePool (S3Context->WritePointers);
FreePool (S3Context);
}
/**
Save the information necessary to replicate a QEMU_LOADER_WRITE_POINTER
command during S3 resume, in condensed format.
This function is to be called from ProcessCmdWritePointer(), after all the
sanity checks have passed, and before the fw_cfg operations are performed.
@param[in,out] S3Context The S3_CONTEXT object into which the caller wants
to save the information that was derived from
QEMU_LOADER_WRITE_POINTER.
@param[in] PointerItem The FIRMWARE_CONFIG_ITEM that
QEMU_LOADER_WRITE_POINTER.PointerFile was resolved
to, expressed as a UINT16 value.
@param[in] PointerSize Copied directly from
QEMU_LOADER_WRITE_POINTER.PointerSize.
@param[in] PointerOffset Copied directly from
QEMU_LOADER_WRITE_POINTER.PointerOffset.
@param[in] PointerValue The base address of the allocated / downloaded
fw_cfg blob that is identified by
QEMU_LOADER_WRITE_POINTER.PointeeFile, plus
QEMU_LOADER_WRITE_POINTER.PointeeOffset.
@retval EFI_SUCCESS The information derived from
QEMU_LOADER_WRITE_POINTER has been successfully
absorbed into S3Context.
@retval EFI_OUT_OF_RESOURCES No room available in S3Context.
**/
EFI_STATUS
SaveCondensedWritePointerToS3Context (
IN OUT S3_CONTEXT *S3Context,
IN UINT16 PointerItem,
IN UINT8 PointerSize,
IN UINT32 PointerOffset,
IN UINT64 PointerValue
)
{
CONDENSED_WRITE_POINTER *Condensed;
if (S3Context->Used == S3Context->Allocated) {
return EFI_OUT_OF_RESOURCES;
}
Condensed = S3Context->WritePointers + S3Context->Used;
Condensed->PointerItem = PointerItem;
Condensed->PointerSize = PointerSize;
Condensed->PointerOffset = PointerOffset;
Condensed->PointerValue = PointerValue;
DEBUG ((
DEBUG_VERBOSE,
"%a: 0x%04x/[0x%08x+%d] := 0x%Lx (%Lu)\n",
__FUNCTION__,
PointerItem,
PointerOffset,
PointerSize,
PointerValue,
(UINT64)S3Context->Used
));
++S3Context->Used;
return EFI_SUCCESS;
}
/**
FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION provided to QemuFwCfgS3Lib.
**/
STATIC
VOID
EFIAPI
AppendFwCfgBootScript (
IN OUT VOID *Context OPTIONAL,
IN OUT VOID *ExternalScratchBuffer
)
{
S3_CONTEXT *S3Context;
SCRATCH_BUFFER *ScratchBuffer;
UINTN Index;
S3Context = Context;
ScratchBuffer = ExternalScratchBuffer;
for (Index = 0; Index < S3Context->Used; ++Index) {
CONST CONDENSED_WRITE_POINTER *Condensed;
RETURN_STATUS Status;
Condensed = &S3Context->WritePointers[Index];
Status = QemuFwCfgS3ScriptSkipBytes (
Condensed->PointerItem,
Condensed->PointerOffset
);
if (RETURN_ERROR (Status)) {
goto FatalError;
}
ScratchBuffer->PointerValue = Condensed->PointerValue;
Status = QemuFwCfgS3ScriptWriteBytes (-1, Condensed->PointerSize);
if (RETURN_ERROR (Status)) {
goto FatalError;
}
}
DEBUG ((DEBUG_VERBOSE, "%a: boot script fragment saved\n", __FUNCTION__));
ReleaseS3Context (S3Context);
return;
FatalError:
ASSERT (FALSE);
CpuDeadLoop ();
}
/**
Translate and append the information from an S3_CONTEXT object to the ACPI S3
Boot Script.
The effects of a successful call to this function cannot be undone.
@param[in] S3Context The S3_CONTEXT object to translate to ACPI S3 Boot
Script opcodes. If the function returns successfully,
the caller must set the S3Context pointer -- originally
returned by AllocateS3Context() -- immediately to NULL,
because the ownership of S3Context has been transferred.
@retval EFI_SUCCESS The translation of S3Context to ACPI S3 Boot Script
opcodes has been successfully executed or queued. (This
includes the case when S3Context was empty on input and
no ACPI S3 Boot Script opcodes have been necessary to
produce.)
@return Error codes from underlying functions.
**/
EFI_STATUS
TransferS3ContextToBootScript (
IN S3_CONTEXT *S3Context
)
{
RETURN_STATUS Status;
if (S3Context->Used == 0) {
ReleaseS3Context (S3Context);
return EFI_SUCCESS;
}
Status = QemuFwCfgS3CallWhenBootScriptReady (
AppendFwCfgBootScript,
S3Context,
sizeof (SCRATCH_BUFFER)
);
return (EFI_STATUS)Status;
}