Make this library depend on the FDT client protocol to access the host supplied device tree directly rather than depending on VirtFdtDxe to set them using dynamic PCDs.
Since this library is used by several drivers (BdsDxe, SmbiosDxe and QemuFwCfgAcpiPlatformDxe), we will end up parsing the device tree and the fwcfg node at least three times. However, no dynamic PCDs are involved anymore, and will even be removed completely in a subsequent patch. So the conversion is not optimal, but guaranteed to be safe. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c | 63 ++++++++++++++++++-- ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf | 10 ++-- 2 files changed, 64 insertions(+), 9 deletions(-) diff --git a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c index 303dc520c6eb..34f31517d0fa 100644 --- a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c +++ b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c @@ -14,12 +14,17 @@ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ +#include <Uefi.h> + #include <Library/BaseLib.h> #include <Library/BaseMemoryLib.h> #include <Library/DebugLib.h> #include <Library/IoLib.h> #include <Library/PcdLib.h> #include <Library/QemuFwCfgLib.h> +#include <Library/UefiBootServicesTableLib.h> + +#include <Protocol/FdtClient.h> STATIC UINTN mFwCfgSelectorAddress; STATIC UINTN mFwCfgDataAddress; @@ -115,8 +120,59 @@ QemuFwCfgInitialize ( VOID ) { - mFwCfgSelectorAddress = (UINTN)PcdGet64 (PcdFwCfgSelectorAddress); - mFwCfgDataAddress = (UINTN)PcdGet64 (PcdFwCfgDataAddress); + EFI_STATUS Status; + FDT_CLIENT_PROTOCOL *FdtClient; + CONST UINT64 *Reg; + UINT32 RegElemSize, RegSize; + UINT64 FwCfgSelectorSize; + UINT64 FwCfgDataSize; + UINT64 FwCfgDmaSize; + + Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL, + (VOID **)&FdtClient); + ASSERT_EFI_ERROR (Status); + + Status = FdtClient->FindCompatibleNodeReg (FdtClient, "qemu,fw-cfg-mmio", + (CONST VOID **)&Reg, &RegElemSize, &RegSize); + if (EFI_ERROR (Status)) { + return Status; + } + + ASSERT (RegElemSize == sizeof (UINT64)); + ASSERT (RegSize == 2 * sizeof (UINT64)); + + mFwCfgDataAddress = SwapBytes64 (Reg[0]); + FwCfgDataSize = 8; + mFwCfgSelectorAddress = mFwCfgDataAddress + 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 (mFwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1); + ASSERT (mFwCfgDataAddress <= MAX_UINTN - FwCfgDataSize + 1); + + DEBUG ((EFI_D_INFO, "Found FwCfg @ 0x%Lx/0x%Lx\n", mFwCfgSelectorAddress, + mFwCfgDataAddress)); + + if (SwapBytes64 (Reg[1]) >= 0x18) { + mFwCfgDmaAddress = mFwCfgDataAddress + 0x10; + FwCfgDmaSize = 0x08; + + // + // See explanation above. + // + ASSERT (mFwCfgDmaAddress <= MAX_UINTN - FwCfgDmaSize + 1); + + DEBUG ((EFI_D_INFO, "Found FwCfg DMA @ 0x%Lx\n", mFwCfgDmaAddress)); + } if (InternalQemuFwCfgIsAvailable ()) { UINT32 Signature; @@ -128,13 +184,12 @@ QemuFwCfgInitialize ( // 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 (PcdGet64 (PcdFwCfgDmaAddress) != 0) { + if (mFwCfgDmaAddress != 0) { UINT32 Features; QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion); Features = QemuFwCfgRead32 (); if ((Features & BIT1) != 0) { - mFwCfgDmaAddress = PcdGet64 (PcdFwCfgDmaAddress); InternalQemuFwCfgReadBytes = DmaReadBytes; } } diff --git a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf index 298aa6edfb26..cab42e4fd532 100644 --- a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf +++ b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf @@ -46,9 +46,9 @@ [LibraryClasses] BaseMemoryLib DebugLib IoLib - PcdLib -[Pcd] - gArmVirtTokenSpaceGuid.PcdFwCfgSelectorAddress - gArmVirtTokenSpaceGuid.PcdFwCfgDataAddress - gArmVirtTokenSpaceGuid.PcdFwCfgDmaAddress +[Protocols] + gFdtClientProtocolGuid ## CONSUMES + +[Depex] + gFdtClientProtocolGuid -- 2.5.0 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
