123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633 |
- /** @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>
- SPDX-License-Identifier: BSD-2-Clause-Patent
- **/
- #include <Uefi.h>
- #include <Library/BaseLib.h>
- #include <Library/BaseMemoryLib.h>
- #include <Library/DebugLib.h>
- #include <Library/IoLib.h>
- #include <Library/QemuFwCfgLib.h>
- #include <Library/UefiBootServicesTableLib.h>
- #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;
- /**
- Returns a boolean indicating if the firmware configuration interface
- is available or not.
- This function may change fw_cfg state.
- @retval TRUE The interface is available
- @retval FALSE The interface is not available
- **/
- BOOLEAN
- EFIAPI
- QemuFwCfgIsAvailable (
- VOID
- )
- {
- 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 ((EFI_D_WARN,
- "%a: No 'qemu,fw-cfg-mmio' compatible DT node found (Status == %r)\n",
- __FUNCTION__, 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 ((EFI_D_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 ((EFI_D_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.
- Following this call, any data read from this item will start from the
- beginning of the configuration item's data.
- @param[in] QemuFwCfgItem Firmware Configuration item to read
- **/
- VOID
- EFIAPI
- QemuFwCfgSelectItem (
- IN FIRMWARE_CONFIG_ITEM QemuFwCfgItem
- )
- {
- if (QemuFwCfgIsAvailable ()) {
- MmioWrite16 (mFwCfgSelectorAddress, SwapBytes16 ((UINT16)QemuFwCfgItem));
- }
- }
- /**
- Slow READ_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- MmioReadBytes (
- IN UINTN Size,
- IN VOID *Buffer OPTIONAL
- )
- {
- UINTN Left;
- UINT8 *Ptr;
- UINT8 *End;
- #ifdef MDE_CPU_AARCH64
- Left = Size & 7;
- #else
- Left = Size & 3;
- #endif
- Size -= Left;
- Ptr = Buffer;
- End = Ptr + Size;
- #ifdef MDE_CPU_AARCH64
- while (Ptr < End) {
- *(UINT64 *)Ptr = MmioRead64 (mFwCfgDataAddress);
- Ptr += 8;
- }
- if (Left & 4) {
- *(UINT32 *)Ptr = MmioRead32 (mFwCfgDataAddress);
- Ptr += 4;
- }
- #else
- while (Ptr < End) {
- *(UINT32 *)Ptr = MmioRead32 (mFwCfgDataAddress);
- Ptr += 4;
- }
- #endif
- if (Left & 2) {
- *(UINT16 *)Ptr = MmioRead16 (mFwCfgDataAddress);
- Ptr += 2;
- }
- if (Left & 1) {
- *Ptr = MmioRead8 (mFwCfgDataAddress);
- }
- }
- /**
- 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.
- **/
- STATIC
- VOID
- DmaTransferBytes (
- IN UINTN Size,
- IN OUT VOID *Buffer OPTIONAL,
- IN UINT32 Control
- )
- {
- volatile FW_CFG_DMA_ACCESS Access;
- UINT32 Status;
- ASSERT (Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||
- Control == FW_CFG_DMA_CTL_SKIP);
- if (Size == 0) {
- return;
- }
- ASSERT (Size <= MAX_UINT32);
- Access.Control = SwapBytes32 (Control);
- Access.Length = SwapBytes32 ((UINT32)Size);
- Access.Address = SwapBytes64 ((UINT64)(UINTN)Buffer);
- //
- // We shouldn't start the transfer before setting up Access.
- //
- MemoryFence ();
- //
- // This will fire off the transfer.
- //
- #ifdef MDE_CPU_AARCH64
- MmioWrite64 (mFwCfgDmaAddress, SwapBytes64 ((UINT64)&Access));
- #else
- MmioWrite32 ((UINT32)(mFwCfgDmaAddress + 4), SwapBytes32 ((UINT32)&Access));
- #endif
- //
- // We shouldn't look at Access.Control before starting the transfer.
- //
- MemoryFence ();
- do {
- Status = SwapBytes32 (Access.Control);
- ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);
- } while (Status != 0);
- //
- // The caller will want to access the transferred data.
- //
- MemoryFence ();
- }
- /**
- Fast READ_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- DmaReadBytes (
- IN UINTN Size,
- IN VOID *Buffer OPTIONAL
- )
- {
- DmaTransferBytes (Size, Buffer, FW_CFG_DMA_CTL_READ);
- }
- /**
- Reads firmware configuration bytes into a buffer
- If called multiple times, then the data read will continue at the offset of
- the firmware configuration item where the previous read ended.
- @param[in] Size Size in bytes to read
- @param[in] Buffer Buffer to store data into
- **/
- VOID
- EFIAPI
- QemuFwCfgReadBytes (
- IN UINTN Size,
- IN VOID *Buffer
- )
- {
- if (QemuFwCfgIsAvailable ()) {
- InternalQemuFwCfgReadBytes (Size, Buffer);
- } else {
- ZeroMem (Buffer, Size);
- }
- }
- /**
- Slow WRITE_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- MmioWriteBytes (
- IN UINTN Size,
- IN VOID *Buffer OPTIONAL
- )
- {
- UINTN Idx;
- for (Idx = 0; Idx < Size; ++Idx) {
- MmioWrite8 (mFwCfgDataAddress, ((UINT8 *)Buffer)[Idx]);
- }
- }
- /**
- Fast WRITE_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- DmaWriteBytes (
- IN UINTN Size,
- IN VOID *Buffer OPTIONAL
- )
- {
- DmaTransferBytes (Size, Buffer, FW_CFG_DMA_CTL_WRITE);
- }
- /**
- Write firmware configuration bytes from a buffer
- If called multiple times, then the data written will continue at the offset
- of the firmware configuration item where the previous write ended.
- @param[in] Size Size in bytes to write
- @param[in] Buffer Buffer to read data from
- **/
- VOID
- EFIAPI
- QemuFwCfgWriteBytes (
- IN UINTN Size,
- IN VOID *Buffer
- )
- {
- if (QemuFwCfgIsAvailable ()) {
- InternalQemuFwCfgWriteBytes (Size, Buffer);
- }
- }
- /**
- Slow SKIP_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- MmioSkipBytes (
- IN UINTN Size
- )
- {
- UINTN ChunkSize;
- UINT8 SkipBuffer[256];
- //
- // Emulate the skip by reading data in chunks, and throwing it away. The
- // implementation below doesn't affect the static data footprint for client
- // modules. Large skips are not expected, therefore this fallback is not
- // performance critical. The size of SkipBuffer is thought not to exert a
- // large pressure on the stack.
- //
- while (Size > 0) {
- ChunkSize = MIN (Size, sizeof SkipBuffer);
- MmioReadBytes (ChunkSize, SkipBuffer);
- Size -= ChunkSize;
- }
- }
- /**
- Fast SKIP_BYTES_FUNCTION.
- **/
- STATIC
- VOID
- EFIAPI
- DmaSkipBytes (
- IN UINTN Size
- )
- {
- DmaTransferBytes (Size, NULL, FW_CFG_DMA_CTL_SKIP);
- }
- /**
- Skip bytes in the firmware configuration item.
- Increase the offset of the firmware configuration item without transferring
- bytes between the item and a caller-provided buffer. Subsequent read, write
- or skip operations will commence at the increased offset.
- @param[in] Size Number of bytes to skip.
- **/
- VOID
- EFIAPI
- QemuFwCfgSkipBytes (
- IN UINTN Size
- )
- {
- if (QemuFwCfgIsAvailable ()) {
- InternalQemuFwCfgSkipBytes (Size);
- }
- }
- /**
- Reads a UINT8 firmware configuration value
- @return Value of Firmware Configuration item read
- **/
- UINT8
- EFIAPI
- QemuFwCfgRead8 (
- VOID
- )
- {
- UINT8 Result;
- QemuFwCfgReadBytes (sizeof Result, &Result);
- return Result;
- }
- /**
- Reads a UINT16 firmware configuration value
- @return Value of Firmware Configuration item read
- **/
- UINT16
- EFIAPI
- QemuFwCfgRead16 (
- VOID
- )
- {
- UINT16 Result;
- QemuFwCfgReadBytes (sizeof Result, &Result);
- return Result;
- }
- /**
- Reads a UINT32 firmware configuration value
- @return Value of Firmware Configuration item read
- **/
- UINT32
- EFIAPI
- QemuFwCfgRead32 (
- VOID
- )
- {
- UINT32 Result;
- QemuFwCfgReadBytes (sizeof Result, &Result);
- return Result;
- }
- /**
- Reads a UINT64 firmware configuration value
- @return Value of Firmware Configuration item read
- **/
- UINT64
- EFIAPI
- QemuFwCfgRead64 (
- VOID
- )
- {
- UINT64 Result;
- QemuFwCfgReadBytes (sizeof Result, &Result);
- return Result;
- }
- /**
- Find the configuration item corresponding to the firmware configuration file.
- @param[in] Name Name of file to look up.
- @param[out] Item Configuration item corresponding to the file, to be passed
- to QemuFwCfgSelectItem ().
- @param[out] Size Number of bytes in the file.
- @retval RETURN_SUCCESS If file is found.
- @retval RETURN_NOT_FOUND If file is not found.
- @retval RETURN_UNSUPPORTED If firmware configuration is unavailable.
- **/
- RETURN_STATUS
- EFIAPI
- QemuFwCfgFindFile (
- IN CONST CHAR8 *Name,
- OUT FIRMWARE_CONFIG_ITEM *Item,
- OUT UINTN *Size
- )
- {
- UINT32 Count;
- UINT32 Idx;
- if (!QemuFwCfgIsAvailable ()) {
- return RETURN_UNSUPPORTED;
- }
- QemuFwCfgSelectItem (QemuFwCfgItemFileDir);
- Count = SwapBytes32 (QemuFwCfgRead32 ());
- for (Idx = 0; Idx < Count; ++Idx) {
- UINT32 FileSize;
- UINT16 FileSelect;
- CHAR8 FName[QEMU_FW_CFG_FNAME_SIZE];
- FileSize = QemuFwCfgRead32 ();
- FileSelect = QemuFwCfgRead16 ();
- QemuFwCfgRead16 (); // skip the field called "reserved"
- InternalQemuFwCfgReadBytes (sizeof (FName), FName);
- if (AsciiStrCmp (Name, FName) == 0) {
- *Item = (FIRMWARE_CONFIG_ITEM) SwapBytes16 (FileSelect);
- *Size = SwapBytes32 (FileSize);
- return RETURN_SUCCESS;
- }
- }
- return RETURN_NOT_FOUND;
- }
|