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From: "Ard Biesheuvel" <ardb@kernel.org>
To: Chao Li <lichao@loongson.cn>
Cc: devel@edk2.groups.io, Ard Biesheuvel <ardb+tianocore@kernel.org>,
	 Jiewen Yao <jiewen.yao@intel.com>,
	Gerd Hoffmann <kraxel@redhat.com>,
	 Leif Lindholm <quic_llindhol@quicinc.com>,
	Sami Mujawar <sami.mujawar@arm.com>,
	 Sunil V L <sunilvl@ventanamicro.com>,
	Andrei Warkentin <andrei.warkentin@intel.com>
Subject: Re: [edk2-devel] [PATCH v3 1/7] OvmfPkg: Separate QemuFwCfgLibMmio.c into two files
Date: Thu, 25 Apr 2024 14:58:18 +0200	[thread overview]
Message-ID: <CAMj1kXEmuEzAx-Sm2VP1ZGqVjZ7dmUC1Z8rkm9yGCLECFQuPdA@mail.gmail.com> (raw)
In-Reply-To: <20240425121257.3009757-1-lichao@loongson.cn>

On Thu, 25 Apr 2024 at 14:13, Chao Li <lichao@loongson.cn> wrote:
>
> Separate QemuFwCfgLibMmio.c into two files named QemuFwCfgLibMmio.c and
> QemuFwCfgLibMmioDxe.c, added a new header named
> QemuFwCfgLibMmioInternal.h for MMIO version.
>
> Build-tested only (with "ArmVirtQemu.dsc and RiscVVirtQemu.dsc").
>
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4755
>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Sunil V L <sunilvl@ventanamicro.com>
> Cc: Andrei Warkentin <andrei.warkentin@intel.com>
> Signed-off-by: Chao Li <lichao@loongson.cn>
> ---
>  .../Library/QemuFwCfgLib/QemuFwCfgLibMmio.c   | 194 +-----------------
>  .../Library/QemuFwCfgLib/QemuFwCfgLibMmio.inf |   4 +-
>  .../QemuFwCfgLib/QemuFwCfgLibMmioInternal.h   | 179 ++++++++++++++++
>  .../Library/QemuFwCfgLib/QemuFwCfgMmioDxe.c   | 153 ++++++++++++++
>  4 files changed, 340 insertions(+), 190 deletions(-)
>  create mode 100644 OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmioInternal.h
>  create mode 100644 OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgMmioDxe.c
>
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.c
> index 115a210759..dc949c8e26 100644
> --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.c
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.c
> @@ -1,10 +1,9 @@
>  /** @file
>
> -  Stateful and implicitly initialized fw_cfg library implementation.
> -
>    Copyright (C) 2013 - 2014, Red Hat, Inc.
>    Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
>    (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
> +  Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
>

Please only claim copyright for code that you wrote, not for code that
you just moved between files.

>    SPDX-License-Identifier: BSD-2-Clause-Patent
>  **/
> @@ -20,63 +19,7 @@
>
>  #include <Protocol/FdtClient.h>
>
> -STATIC UINTN  mFwCfgSelectorAddress;
> -STATIC UINTN  mFwCfgDataAddress;
> -STATIC UINTN  mFwCfgDmaAddress;
> -
> -/**
> -  Reads firmware configuration bytes into a buffer
> -
> -  @param[in] Size    Size in bytes to read
> -  @param[in] Buffer  Buffer to store data into  (OPTIONAL if Size is 0)
> -
> -**/
> -typedef
> -VOID(EFIAPI READ_BYTES_FUNCTION)(
> -  IN UINTN Size,
> -  IN VOID  *Buffer OPTIONAL
> -  );
> -
> -/**
> -  Writes bytes from a buffer to firmware configuration
> -
> -  @param[in] Size    Size in bytes to write
> -  @param[in] Buffer  Buffer to transfer data from (OPTIONAL if Size is 0)
> -
> -**/
> -typedef
> -VOID(EFIAPI WRITE_BYTES_FUNCTION)(
> -  IN UINTN Size,
> -  IN VOID  *Buffer OPTIONAL
> -  );
> -
> -/**
> -  Skips bytes in firmware configuration
> -
> -  @param[in] Size  Size in bytes to skip
> -
> -**/
> -typedef
> -VOID(EFIAPI SKIP_BYTES_FUNCTION)(
> -  IN UINTN Size
> -  );
> -
> -//
> -// Forward declaration of the two implementations we have.
> -//
> -STATIC READ_BYTES_FUNCTION   MmioReadBytes;
> -STATIC WRITE_BYTES_FUNCTION  MmioWriteBytes;
> -STATIC SKIP_BYTES_FUNCTION   MmioSkipBytes;
> -STATIC READ_BYTES_FUNCTION   DmaReadBytes;
> -STATIC WRITE_BYTES_FUNCTION  DmaWriteBytes;
> -STATIC SKIP_BYTES_FUNCTION   DmaSkipBytes;
> -
> -//
> -// These correspond to the implementation we detect at runtime.
> -//
> -STATIC READ_BYTES_FUNCTION   *InternalQemuFwCfgReadBytes  = MmioReadBytes;
> -STATIC WRITE_BYTES_FUNCTION  *InternalQemuFwCfgWriteBytes = MmioWriteBytes;
> -STATIC SKIP_BYTES_FUNCTION   *InternalQemuFwCfgSkipBytes  = MmioSkipBytes;
> +#include "QemuFwCfgLibMmioInternal.h"
>
>  /**
>    Returns a boolean indicating if the firmware configuration interface
> @@ -97,126 +40,6 @@ QemuFwCfgIsAvailable (
>    return (BOOLEAN)(mFwCfgSelectorAddress != 0 && mFwCfgDataAddress != 0);
>  }
>
> -RETURN_STATUS
> -EFIAPI
> -QemuFwCfgInitialize (
> -  VOID
> -  )
> -{
> -  EFI_STATUS           Status;
> -  FDT_CLIENT_PROTOCOL  *FdtClient;
> -  CONST UINT64         *Reg;
> -  UINT32               RegSize;
> -  UINTN                AddressCells, SizeCells;
> -  UINT64               FwCfgSelectorAddress;
> -  UINT64               FwCfgSelectorSize;
> -  UINT64               FwCfgDataAddress;
> -  UINT64               FwCfgDataSize;
> -  UINT64               FwCfgDmaAddress;
> -  UINT64               FwCfgDmaSize;
> -
> -  Status = gBS->LocateProtocol (
> -                  &gFdtClientProtocolGuid,
> -                  NULL,
> -                  (VOID **)&FdtClient
> -                  );
> -  ASSERT_EFI_ERROR (Status);
> -
> -  Status = FdtClient->FindCompatibleNodeReg (
> -                        FdtClient,
> -                        "qemu,fw-cfg-mmio",
> -                        (CONST VOID **)&Reg,
> -                        &AddressCells,
> -                        &SizeCells,
> -                        &RegSize
> -                        );
> -  if (EFI_ERROR (Status)) {
> -    DEBUG ((
> -      DEBUG_WARN,
> -      "%a: No 'qemu,fw-cfg-mmio' compatible DT node found (Status == %r)\n",
> -      __func__,
> -      Status
> -      ));
> -    return EFI_SUCCESS;
> -  }
> -
> -  ASSERT (AddressCells == 2);
> -  ASSERT (SizeCells == 2);
> -  ASSERT (RegSize == 2 * sizeof (UINT64));
> -
> -  FwCfgDataAddress     = SwapBytes64 (Reg[0]);
> -  FwCfgDataSize        = 8;
> -  FwCfgSelectorAddress = FwCfgDataAddress + FwCfgDataSize;
> -  FwCfgSelectorSize    = 2;
> -
> -  //
> -  // The following ASSERT()s express
> -  //
> -  //   Address + Size - 1 <= MAX_UINTN
> -  //
> -  // for both registers, that is, that the last byte in each MMIO range is
> -  // expressible as a MAX_UINTN. The form below is mathematically
> -  // equivalent, and it also prevents any unsigned overflow before the
> -  // comparison.
> -  //
> -  ASSERT (FwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1);
> -  ASSERT (FwCfgDataAddress     <= MAX_UINTN - FwCfgDataSize     + 1);
> -
> -  mFwCfgSelectorAddress = FwCfgSelectorAddress;
> -  mFwCfgDataAddress     = FwCfgDataAddress;
> -
> -  DEBUG ((
> -    DEBUG_INFO,
> -    "Found FwCfg @ 0x%Lx/0x%Lx\n",
> -    FwCfgSelectorAddress,
> -    FwCfgDataAddress
> -    ));
> -
> -  if (SwapBytes64 (Reg[1]) >= 0x18) {
> -    FwCfgDmaAddress = FwCfgDataAddress + 0x10;
> -    FwCfgDmaSize    = 0x08;
> -
> -    //
> -    // See explanation above.
> -    //
> -    ASSERT (FwCfgDmaAddress <= MAX_UINTN - FwCfgDmaSize + 1);
> -
> -    DEBUG ((DEBUG_INFO, "Found FwCfg DMA @ 0x%Lx\n", FwCfgDmaAddress));
> -  } else {
> -    FwCfgDmaAddress = 0;
> -  }
> -
> -  if (QemuFwCfgIsAvailable ()) {
> -    UINT32  Signature;
> -
> -    QemuFwCfgSelectItem (QemuFwCfgItemSignature);
> -    Signature = QemuFwCfgRead32 ();
> -    if (Signature == SIGNATURE_32 ('Q', 'E', 'M', 'U')) {
> -      //
> -      // For DMA support, we require the DTB to advertise the register, and the
> -      // feature bitmap (which we read without DMA) to confirm the feature.
> -      //
> -      if (FwCfgDmaAddress != 0) {
> -        UINT32  Features;
> -
> -        QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
> -        Features = QemuFwCfgRead32 ();
> -        if ((Features & FW_CFG_F_DMA) != 0) {
> -          mFwCfgDmaAddress            = FwCfgDmaAddress;
> -          InternalQemuFwCfgReadBytes  = DmaReadBytes;
> -          InternalQemuFwCfgWriteBytes = DmaWriteBytes;
> -          InternalQemuFwCfgSkipBytes  = DmaSkipBytes;
> -        }
> -      }
> -    } else {
> -      mFwCfgSelectorAddress = 0;
> -      mFwCfgDataAddress     = 0;
> -    }
> -  }
> -
> -  return RETURN_SUCCESS;
> -}
> -
>  /**
>    Selects a firmware configuration item for reading.
>
> @@ -240,7 +63,6 @@ QemuFwCfgSelectItem (
>  /**
>    Slow READ_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  MmioReadBytes (
> @@ -252,7 +74,7 @@ MmioReadBytes (
>    UINT8  *Ptr;
>    UINT8  *End;
>
> - #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64)
> + #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64) || defined (MDE_CPU_LOONGARCH64)
>    Left = Size & 7;
>   #else
>    Left = Size & 3;
> @@ -262,7 +84,7 @@ MmioReadBytes (
>    Ptr   = Buffer;
>    End   = Ptr + Size;
>
> - #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64)
> + #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64) || defined (MDE_CPU_LOONGARCH64)
>    while (Ptr < End) {
>      *(UINT64 *)Ptr = MmioRead64 (mFwCfgDataAddress);
>      Ptr           += 8;
> @@ -306,7 +128,6 @@ MmioReadBytes (
>                            FW_CFG_DMA_CTL_READ  - read from fw_cfg into Buffer.
>                            FW_CFG_DMA_CTL_SKIP  - skip bytes in fw_cfg.
>  **/
> -STATIC
>  VOID
>  DmaTransferBytes (
>    IN     UINTN   Size,
> @@ -340,7 +161,7 @@ DmaTransferBytes (
>    //
>    // This will fire off the transfer.
>    //
> - #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64)
> + #if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_RISCV64) || defined (MDE_CPU_LOONGARCH64)
>    MmioWrite64 (mFwCfgDmaAddress, SwapBytes64 ((UINT64)&Access));
>   #else
>    MmioWrite32 ((UINT32)(mFwCfgDmaAddress + 4), SwapBytes32 ((UINT32)&Access));
> @@ -365,7 +186,6 @@ DmaTransferBytes (
>  /**
>    Fast READ_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  DmaReadBytes (
> @@ -403,7 +223,6 @@ QemuFwCfgReadBytes (
>  /**
>    Slow WRITE_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  MmioWriteBytes (
> @@ -421,7 +240,6 @@ MmioWriteBytes (
>  /**
>    Fast WRITE_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  DmaWriteBytes (
> @@ -457,7 +275,6 @@ QemuFwCfgWriteBytes (
>  /**
>    Slow SKIP_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  MmioSkipBytes (
> @@ -484,7 +301,6 @@ MmioSkipBytes (
>  /**
>    Fast SKIP_BYTES_FUNCTION.
>  **/
> -STATIC
>  VOID
>  EFIAPI
>  DmaSkipBytes (
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.inf
> index 4b0dfbcb0d..f2596f270e 100644
> --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.inf
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmio.inf
> @@ -4,6 +4,7 @@
>  #
>  #  Copyright (C) 2013 - 2014, Red Hat, Inc.
>  #  Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
> +#  Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
>  #
>  #  SPDX-License-Identifier: BSD-2-Clause-Patent
>  #
> @@ -23,11 +24,12 @@ [Defines]
>  # The following information is for reference only and not required by the build
>  # tools.
>  #
> -#  VALID_ARCHITECTURES           = ARM AARCH64 RISCV64
> +#  VALID_ARCHITECTURES           = ARM AARCH64 RISCV64 LOONGARCH64
>  #
>
>  [Sources]
>    QemuFwCfgLibMmio.c
> +  QemuFwCfgMmioDxe.c
>
>  [Packages]
>    MdePkg/MdePkg.dec
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmioInternal.h b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmioInternal.h
> new file mode 100644
> index 0000000000..d7d645f700
> --- /dev/null
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibMmioInternal.h
> @@ -0,0 +1,179 @@
> +/** @file
> +  Internal interfaces specific to the QemuFwCfgLibMmio instances in OvmfPkg.
> +
> +  Copyright (C) 2016, Red Hat, Inc.
> +  Copyright (C) 2017, Advanced Micro Devices. All rights reserved
> +  Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#ifndef QEMU_FW_CFG_LIB_MMIO_INTERNAL_H_
> +#define QEMU_FW_CFG_LIB_MMIO_INTERNAL_H_
> +
> +extern UINTN  mFwCfgSelectorAddress;
> +extern UINTN  mFwCfgDataAddress;
> +extern UINTN  mFwCfgDmaAddress;
> +

These can remain STATIC and live in the DXE version of the library, no?

> +/**
> +  Reads firmware configuration bytes into a buffer
> +
> +  @param[in] Size    Size in bytes to read
> +  @param[in] Buffer  Buffer to store data into  (OPTIONAL if Size is 0)
> +
> +**/
> +typedef
> +VOID(EFIAPI READ_BYTES_FUNCTION)(
> +  IN UINTN Size,
> +  IN VOID  *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Writes bytes from a buffer to firmware configuration
> +
> +  @param[in] Size    Size in bytes to write
> +  @param[in] Buffer  Buffer to transfer data from (OPTIONAL if Size is 0)
> +
> +**/
> +typedef
> +VOID(EFIAPI WRITE_BYTES_FUNCTION)(
> +  IN UINTN Size,
> +  IN VOID  *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Skips bytes in firmware configuration
> +
> +  @param[in] Size  Size in bytes to skip
> +
> +**/
> +typedef
> +VOID(EFIAPI SKIP_BYTES_FUNCTION)(
> +  IN UINTN Size
> +  );
> +
> +/**
> +  Reads firmware configuration bytes into a buffer
> +
> +  @param[in] Size    Size in bytes to read
> +  @param[in] Buffer  Buffer to store data into  (OPTIONAL if Size is 0)
> +
> +**/
> +extern
> +VOID
> +EFIAPI
> +(*InternalQemuFwCfgReadBytes) (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer  OPTIONAL
> +  );
> +
> +/**
> +  Writes bytes from a buffer to firmware configuration
> +
> +  @param[in] Size    Size in bytes to write
> +  @param[in] Buffer  Buffer to transfer data from (OPTIONAL if Size is 0)
> +
> +**/
> +extern
> +VOID
> +EFIAPI
> +(*InternalQemuFwCfgWriteBytes) (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer  OPTIONAL
> +  );
> +
> +/**
> +  Skips bytes in firmware configuration
> +
> +  @param[in] Size  Size in bytes to skip
> +
> +**/
> +extern
> +VOID
> +EFIAPI
> +(*InternalQemuFwCfgSkipBytes) (
> +  IN UINTN  Size
> +  );
> +
> +/**
> +  Slow READ_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +MmioReadBytes (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Slow WRITE_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +MmioWriteBytes (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Slow SKIP_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +MmioSkipBytes (
> +  IN UINTN  Size
> +  );
> +
> +/**
> +  Fast READ_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +DmaReadBytes (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Fast WRITE_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +DmaWriteBytes (
> +  IN UINTN  Size,
> +  IN VOID   *Buffer OPTIONAL
> +  );
> +
> +/**
> +  Fast SKIP_BYTES_FUNCTION.
> +**/
> +VOID
> +EFIAPI
> +DmaSkipBytes (
> +  IN UINTN  Size
> +  );
> +
> +/**
> +  Transfer an array of bytes, or skip a number of bytes, using the DMA
> +  interface.
> +
> +  @param[in]     Size     Size in bytes to transfer or skip.
> +
> +  @param[in,out] Buffer   Buffer to read data into or write data from. Ignored,
> +                          and may be NULL, if Size is zero, or Control is
> +                          FW_CFG_DMA_CTL_SKIP.
> +
> +  @param[in]     Control  One of the following:
> +                          FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.
> +                          FW_CFG_DMA_CTL_READ  - read from fw_cfg into Buffer.
> +                          FW_CFG_DMA_CTL_SKIP  - skip bytes in fw_cfg.
> +**/
> +VOID
> +DmaTransferBytes (
> +  IN     UINTN   Size,
> +  IN OUT VOID    *Buffer OPTIONAL,
> +  IN     UINT32  Control
> +  );
> +
> +#endif
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgMmioDxe.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgMmioDxe.c
> new file mode 100644
> index 0000000000..4844a42a36
> --- /dev/null
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgMmioDxe.c
> @@ -0,0 +1,153 @@
> +/** @file
> +
> +  Stateful and implicitly initialized fw_cfg library implementation.
> +
> +  Copyright (C) 2013 - 2014, Red Hat, Inc.
> +  Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
> +  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
> +  Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +
> +#include <Library/BaseLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/QemuFwCfgLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +#include <Protocol/FdtClient.h>
> +
> +#include "QemuFwCfgLibMmioInternal.h"
> +
> +UINTN  mFwCfgSelectorAddress;
> +UINTN  mFwCfgDataAddress;
> +UINTN  mFwCfgDmaAddress;
> +
> +//
> +// These correspond to the implementation we detect at runtime.
> +//
> +READ_BYTES_FUNCTION   *InternalQemuFwCfgReadBytes  = MmioReadBytes;
> +WRITE_BYTES_FUNCTION  *InternalQemuFwCfgWriteBytes = MmioWriteBytes;
> +SKIP_BYTES_FUNCTION   *InternalQemuFwCfgSkipBytes  = MmioSkipBytes;
> +

These are duplicated later in the PEI version of the library, right?
So they can live in the shared .c file

> +RETURN_STATUS
> +EFIAPI
> +QemuFwCfgInitialize (
> +  VOID
> +  )
> +{
> +  EFI_STATUS           Status;
> +  FDT_CLIENT_PROTOCOL  *FdtClient;
> +  CONST UINT64         *Reg;
> +  UINT32               RegSize;
> +  UINTN                AddressCells, SizeCells;
> +  UINT64               FwCfgSelectorAddress;
> +  UINT64               FwCfgSelectorSize;
> +  UINT64               FwCfgDataAddress;
> +  UINT64               FwCfgDataSize;
> +  UINT64               FwCfgDmaAddress;
> +  UINT64               FwCfgDmaSize;
> +
> +  Status = gBS->LocateProtocol (
> +                  &gFdtClientProtocolGuid,
> +                  NULL,
> +                  (VOID **)&FdtClient
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +
> +  Status = FdtClient->FindCompatibleNodeReg (
> +                        FdtClient,
> +                        "qemu,fw-cfg-mmio",
> +                        (CONST VOID **)&Reg,
> +                        &AddressCells,
> +                        &SizeCells,
> +                        &RegSize
> +                        );
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((
> +      DEBUG_WARN,
> +      "%a: No 'qemu,fw-cfg-mmio' compatible DT node found (Status == %r)\n",
> +      __func__,
> +      Status
> +      ));
> +    return EFI_SUCCESS;
> +  }
> +
> +  ASSERT (AddressCells == 2);
> +  ASSERT (SizeCells == 2);
> +  ASSERT (RegSize == 2 * sizeof (UINT64));
> +
> +  FwCfgDataAddress     = SwapBytes64 (Reg[0]);
> +  FwCfgDataSize        = 8;
> +  FwCfgSelectorAddress = FwCfgDataAddress + FwCfgDataSize;
> +  FwCfgSelectorSize    = 2;
> +
> +  //
> +  // The following ASSERT()s express
> +  //
> +  //   Address + Size - 1 <= MAX_UINTN
> +  //
> +  // for both registers, that is, that the last byte in each MMIO range is
> +  // expressible as a MAX_UINTN. The form below is mathematically
> +  // equivalent, and it also prevents any unsigned overflow before the
> +  // comparison.
> +  //
> +  ASSERT (FwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1);
> +  ASSERT (FwCfgDataAddress     <= MAX_UINTN - FwCfgDataSize     + 1);
> +
> +  mFwCfgSelectorAddress = FwCfgSelectorAddress;
> +  mFwCfgDataAddress     = FwCfgDataAddress;
> +
> +  DEBUG ((
> +    DEBUG_INFO,
> +    "Found FwCfg @ 0x%Lx/0x%Lx\n",
> +    FwCfgSelectorAddress,
> +    FwCfgDataAddress
> +    ));
> +
> +  if (SwapBytes64 (Reg[1]) >= 0x18) {
> +    FwCfgDmaAddress = FwCfgDataAddress + 0x10;
> +    FwCfgDmaSize    = 0x08;
> +
> +    //
> +    // See explanation above.
> +    //
> +    ASSERT (FwCfgDmaAddress <= MAX_UINTN - FwCfgDmaSize + 1);
> +
> +    DEBUG ((DEBUG_INFO, "Found FwCfg DMA @ 0x%Lx\n", FwCfgDmaAddress));
> +  } else {
> +    FwCfgDmaAddress = 0;
> +  }
> +
> +  if (QemuFwCfgIsAvailable ()) {
> +    UINT32  Signature;
> +
> +    QemuFwCfgSelectItem (QemuFwCfgItemSignature);
> +    Signature = QemuFwCfgRead32 ();
> +    if (Signature == SIGNATURE_32 ('Q', 'E', 'M', 'U')) {
> +      //
> +      // For DMA support, we require the DTB to advertise the register, and the
> +      // feature bitmap (which we read without DMA) to confirm the feature.
> +      //
> +      if (FwCfgDmaAddress != 0) {
> +        UINT32  Features;
> +
> +        QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
> +        Features = QemuFwCfgRead32 ();
> +        if ((Features & FW_CFG_F_DMA) != 0) {
> +          mFwCfgDmaAddress            = FwCfgDmaAddress;
> +          InternalQemuFwCfgReadBytes  = DmaReadBytes;
> +          InternalQemuFwCfgWriteBytes = DmaWriteBytes;
> +          InternalQemuFwCfgSkipBytes  = DmaSkipBytes;
> +        }
> +      }
> +    } else {
> +      mFwCfgSelectorAddress = 0;
> +      mFwCfgDataAddress     = 0;
> +    }
> +  }
> +
> +  return RETURN_SUCCESS;
> +}
> --
> 2.27.0
>


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  reply	other threads:[~2024-04-25 12:58 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25 12:12 [edk2-devel] [PATCH v3 0/7] Adjust the QemuFwCfgLibMmio and add PEI stage Chao Li
2024-04-25 12:12 ` [edk2-devel] [PATCH v3 1/7] OvmfPkg: Separate QemuFwCfgLibMmio.c into two files Chao Li
2024-04-25 12:58   ` Ard Biesheuvel [this message]
2024-04-26  1:12     ` Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 2/7] OvmfPkg: Add the way of HOBs in QemuFwCfgLibMmio Chao Li
2024-04-25 13:02   ` Ard Biesheuvel
2024-04-26  1:20     ` Chao Li
     [not found]     ` <17C9AFCE49F3CEE8.6322@groups.io>
2024-04-26  4:22       ` Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 3/7] OvmfPkg: Add the QemuFwCfgMmioLib PEI stage version Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 4/7] OvmfPkg: Copy the same new INF as QemuFwCfgLibMmio.inf Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 5/7] ArmVirtPkg: Enable QemuFwCfgMmioDxeLib.inf Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 6/7] OvmfPkg/RiscVVirt: " Chao Li
2024-04-25 12:13 ` [edk2-devel] [PATCH v3 7/7] OvmfPkg: Remove QemuFwCfgLibMmio.inf Chao Li

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