Re: [edk2-platforms: PATCH 2/3] Marvell/Drivers: MvSpiOrionDxe: Keep clock enabled at runtime

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Wed, 17 Apr 2019 at 11:06, Marcin Wojtas <mw@semihalf.com> wrote:
>
> Linux MTD subsystem enables the SPI controller clock
> only when explicitly accessing the device. Because of that,
> using variables stored in the SPI flash could cause a hang
> when this clock remained disabled.
>
> Such issue was prevented when booting with the default
> DTB - see commit 124073e4d440 ("Marvell/Armada7k8k: DeviceTree:
> Use fixed clocks"). However in case someone wishes to
> try a different DTB, the issue can become problematic again.
>
> Fix above problem by enabling the clock when accessing
> SPI controller registers or mapped memory region
> AtRuntime. For this purpose add required callbacks
> to the SpiMaster and SpiFlash protocols that are
> called from MvFvbDxe driver.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>

This is really not the right solution. Linux runs UEFI runtime
services on a single core with interrupts enabled, and it thinks it
owns the SPI subsystem if you describe it in the DT, and may decide to
access it at the same time, either in interrupt ot softirq context, or
from another core.


> ---
>  Silicon/Marvell/Marvell.dec                                 |  3 +
>  Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.inf |  3 +
>  Silicon/Marvell/Include/Protocol/Spi.h                      | 10 ++++
>  Silicon/Marvell/Include/Protocol/SpiFlash.h                 |  7 +++
>  Silicon/Marvell/Drivers/Spi/MvFvbDxe/MvFvbDxe.c             | 34 +++++++++++
>  Silicon/Marvell/Drivers/Spi/MvSpiFlashDxe/MvSpiFlashDxe.c   | 11 ++++
>  Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.c   | 63 +++++++++++++++++++-
>  7 files changed, 129 insertions(+), 2 deletions(-)
>
> diff --git a/Silicon/Marvell/Marvell.dec b/Silicon/Marvell/Marvell.dec
> index 7210ba2..201a62f 100644
> --- a/Silicon/Marvell/Marvell.dec
> +++ b/Silicon/Marvell/Marvell.dec
> @@ -138,6 +138,9 @@
>    gMarvellTokenSpaceGuid.PcdI2cBusCount|0|UINT32|0x3000183
>
>  #SPI
> +  gMarvellTokenSpaceGuid.PcdSpiClockFixed|TRUE|BOOLEAN|0x30000054
> +  gMarvellTokenSpaceGuid.PcdSpiClockMask|0|UINT32|0x30000055
> +  gMarvellTokenSpaceGuid.PcdSpiClockRegBase|0|UINT64|0x30000056
>    gMarvellTokenSpaceGuid.PcdSpiRegBase|0|UINT32|0x3000051
>    gMarvellTokenSpaceGuid.PcdSpiMemoryBase|0|UINT64|0x3000059
>    gMarvellTokenSpaceGuid.PcdSpiMaxFrequency|0|UINT32|0x30000052
> diff --git a/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.inf b/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.inf
> index 4779371..1857484 100644
> --- a/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.inf
> +++ b/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.inf
> @@ -59,7 +59,10 @@
>    UefiRuntimeLib
>
>  [FixedPcd]
> +  gMarvellTokenSpaceGuid.PcdSpiClockFixed
>    gMarvellTokenSpaceGuid.PcdSpiClockFrequency
> +  gMarvellTokenSpaceGuid.PcdSpiClockMask
> +  gMarvellTokenSpaceGuid.PcdSpiClockRegBase
>    gMarvellTokenSpaceGuid.PcdSpiMaxFrequency
>    gMarvellTokenSpaceGuid.PcdSpiRegBase
>
> diff --git a/Silicon/Marvell/Include/Protocol/Spi.h b/Silicon/Marvell/Include/Protocol/Spi.h
> index abbad19..4d66f7f 100644
> --- a/Silicon/Marvell/Include/Protocol/Spi.h
> +++ b/Silicon/Marvell/Include/Protocol/Spi.h
> @@ -54,6 +54,9 @@ typedef struct {
>    UINT32 AddrSize;
>    NOR_FLASH_INFO *Info;
>    UINTN HostRegisterBaseAddress;
> +  BOOLEAN HostClockFixed;
> +  UINTN HostClockEnableRegister;
> +  UINT32 HostClockEnableMask;
>    UINTN CoreClock;
>  } SPI_DEVICE;
>
> @@ -107,6 +110,12 @@ EFI_STATUS
>    IN SPI_DEVICE *SpiDev
>    );
>
> +typedef
> +EFI_STATUS
> +(EFIAPI *MV_SPI_POWER_ON) (
> +  IN SPI_DEVICE *SpiDev
> +  );
> +
>  struct _MARVELL_SPI_MASTER_PROTOCOL {
>    MV_SPI_INIT         Init;
>    MV_SPI_READ_WRITE   ReadWrite;
> @@ -114,6 +123,7 @@ struct _MARVELL_SPI_MASTER_PROTOCOL {
>    MV_SPI_SETUP_DEVICE SetupDevice;
>    MV_SPI_FREE_DEVICE  FreeDevice;
>    MV_SPI_CONFIG_RT    ConfigRuntime;
> +  MV_SPI_POWER_ON     ControllerPowerOn;
>  };
>
>  #endif // __MARVELL_SPI_MASTER_PROTOCOL_H__
> diff --git a/Silicon/Marvell/Include/Protocol/SpiFlash.h b/Silicon/Marvell/Include/Protocol/SpiFlash.h
> index e703330..0336dda 100644
> --- a/Silicon/Marvell/Include/Protocol/SpiFlash.h
> +++ b/Silicon/Marvell/Include/Protocol/SpiFlash.h
> @@ -102,6 +102,12 @@ EFI_STATUS
>    IN UINTN                                          EndPercentage
>    );
>
> +typedef
> +EFI_STATUS
> +(EFIAPI *MV_SPI_FLASH_POWER_ON) (
> +  IN SPI_DEVICE *SpiDev
> +  );
> +
>  struct _MARVELL_SPI_FLASH_PROTOCOL {
>    MV_SPI_FLASH_INIT    Init;
>    MV_SPI_FLASH_READ_ID ReadId;
> @@ -110,6 +116,7 @@ struct _MARVELL_SPI_FLASH_PROTOCOL {
>    MV_SPI_FLASH_ERASE   Erase;
>    MV_SPI_FLASH_UPDATE  Update;
>    MV_SPI_FLASH_UPDATE_WITH_PROGRESS  UpdateWithProgress;
> +  MV_SPI_FLASH_POWER_ON FlashPowerOn;
>  };
>
>  #endif // __MV_SPI_FLASH__
> diff --git a/Silicon/Marvell/Drivers/Spi/MvFvbDxe/MvFvbDxe.c b/Silicon/Marvell/Drivers/Spi/MvFvbDxe/MvFvbDxe.c
> index cb006cd..b57f415 100644
> --- a/Silicon/Marvell/Drivers/Spi/MvFvbDxe/MvFvbDxe.c
> +++ b/Silicon/Marvell/Drivers/Spi/MvFvbDxe/MvFvbDxe.c
> @@ -311,6 +311,11 @@ MvFvbGetAttributes (
>
>    FlashInstance = INSTANCE_FROM_FVB_THIS (This);
>
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
> +
>    FwVolHeader = (EFI_FIRMWARE_VOLUME_HEADER *)FlashInstance->RegionBaseAddress;
>    FlashFvbAttributes = (EFI_FVB_ATTRIBUTES_2 *)&(FwVolHeader->Attributes);
>
> @@ -349,10 +354,18 @@ MvFvbSetAttributes (
>    EFI_FVB_ATTRIBUTES_2  OldAttributes;
>    EFI_FVB_ATTRIBUTES_2  FlashFvbAttributes;
>    EFI_FVB_ATTRIBUTES_2  UnchangedAttributes;
> +  FVB_DEVICE            *FlashInstance;
>    UINT32                Capabilities;
>    UINT32                OldStatus;
>    UINT32                NewStatus;
>
> +  FlashInstance = INSTANCE_FROM_FVB_THIS (This);
> +
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
> +
>    //
>    // Obtain attributes from FVB header
>    //
> @@ -468,6 +481,11 @@ MvFvbGetPhysicalAddress (
>
>    FlashInstance = INSTANCE_FROM_FVB_THIS (This);
>
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
> +
>    *Address = FlashInstance->RegionBaseAddress;
>
>    return EFI_SUCCESS;
> @@ -588,6 +606,10 @@ MvFvbRead (
>
>    FlashInstance = INSTANCE_FROM_FVB_THIS (This);
>
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
>
>    // Cache the block size to avoid de-referencing pointers all the time
>    BlockSize = FlashInstance->Media.BlockSize;
> @@ -697,6 +719,11 @@ MvFvbWrite (
>
>    FlashInstance = INSTANCE_FROM_FVB_THIS (This);
>
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
> +
>    DataOffset = GET_DATA_OFFSET (FlashInstance->FvbOffset + Offset,
>                   FlashInstance->StartLba + Lba,
>                   FlashInstance->Media.BlockSize);
> @@ -770,6 +797,11 @@ MvFvbEraseBlocks (
>
>    FlashInstance = INSTANCE_FROM_FVB_THIS (This);
>
> +  // Ensure proper access to the flash device from OS level
> +  if (EfiAtRuntime ()) {
> +    FlashInstance->SpiFlashProtocol->FlashPowerOn (&FlashInstance->SpiDevice);
> +  }
> +
>    Status = EFI_SUCCESS;
>
>    // Detect WriteDisabled state
> @@ -882,11 +914,13 @@ MvFvbVirtualNotifyEvent (
>    // Convert SPI device description
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiDevice.Info);
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiDevice.HostRegisterBaseAddress);
> +  EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiDevice.HostClockEnableRegister);
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiDevice);
>
>    // Convert SpiFlashProtocol
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiFlashProtocol->Erase);
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiFlashProtocol->Write);
> +  EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiFlashProtocol->FlashPowerOn);
>    EfiConvertPointer (0x0, (VOID**)&mFvbDevice->SpiFlashProtocol);
>
>    return;
> diff --git a/Silicon/Marvell/Drivers/Spi/MvSpiFlashDxe/MvSpiFlashDxe.c b/Silicon/Marvell/Drivers/Spi/MvSpiFlashDxe/MvSpiFlashDxe.c
> index d81f6e3..4cc897f 100755
> --- a/Silicon/Marvell/Drivers/Spi/MvSpiFlashDxe/MvSpiFlashDxe.c
> +++ b/Silicon/Marvell/Drivers/Spi/MvSpiFlashDxe/MvSpiFlashDxe.c
> @@ -548,6 +548,15 @@ MvSpiFlashInit (
>  }
>
>  EFI_STATUS
> +EFIAPI
> +MvSpiFlashPowerOn (
> +  IN SPI_DEVICE *Slave
> +  )
> +{
> +  return SpiMasterProtocol->ControllerPowerOn (Slave);
> +}
> +
> +EFI_STATUS
>  MvSpiFlashInitProtocol (
>    IN MARVELL_SPI_FLASH_PROTOCOL *SpiFlashProtocol
>    )
> @@ -560,6 +569,7 @@ MvSpiFlashInitProtocol (
>    SpiFlashProtocol->Erase = MvSpiFlashErase;
>    SpiFlashProtocol->Update = MvSpiFlashUpdate;
>    SpiFlashProtocol->UpdateWithProgress = MvSpiFlashUpdateWithProgress;
> +  SpiFlashProtocol->FlashPowerOn = MvSpiFlashPowerOn;
>
>    return EFI_SUCCESS;
>  }
> @@ -586,6 +596,7 @@ MvSpiFlashVirtualNotifyEvent (
>    //
>    EfiConvertPointer (0x0, (VOID**)&SpiMasterProtocol->ReadWrite);
>    EfiConvertPointer (0x0, (VOID**)&SpiMasterProtocol->Transfer);
> +  EfiConvertPointer (0x0, (VOID**)&SpiMasterProtocol->ControllerPowerOn);
>    EfiConvertPointer (0x0, (VOID**)&SpiMasterProtocol);
>
>    return;
> diff --git a/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.c b/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.c
> index cbf403f..3f7f67e 100755
> --- a/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.c
> +++ b/Silicon/Marvell/Drivers/Spi/MvSpiOrionDxe/MvSpiOrionDxe.c
> @@ -323,6 +323,11 @@ MvSpiSetupSlave (
>    }
>
>    Slave->HostRegisterBaseAddress = PcdGet32 (PcdSpiRegBase);
> +  Slave->HostClockFixed = PcdGetBool (PcdSpiClockFixed);
> +  if (!Slave->HostClockFixed) {
> +    Slave->HostClockEnableRegister = PcdGet64 (PcdSpiClockRegBase);
> +    Slave->HostClockEnableMask = PcdGet32 (PcdSpiClockMask);
> +  }
>    Slave->CoreClock = PcdGet32 (PcdSpiClockFrequency);
>    Slave->MaxFreq = PcdGet32 (PcdSpiMaxFrequency);
>
> @@ -344,12 +349,26 @@ MvSpiFreeSlave (
>
>  EFI_STATUS
>  EFIAPI
> +MvSpiControllerPowerOn (
> +  IN SPI_DEVICE *Slave
> +  )
> +{
> +  if (!Slave->HostClockFixed) {
> +    MmioOr32 (Slave->HostClockEnableRegister, Slave->HostClockEnableMask);
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +EFI_STATUS
> +EFIAPI
>  MvSpiConfigRuntime (
>    IN SPI_DEVICE *Slave
>    )
>  {
>    EFI_STATUS Status;
>    UINTN AlignedAddress;
> +  UINTN ClockEnableAlignedAddress;
>
>    //
>    // Host register base may be not aligned to the page size,
> @@ -373,11 +392,50 @@ MvSpiConfigRuntime (
>                    EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
>    if (EFI_ERROR (Status)) {
>      DEBUG ((DEBUG_ERROR, "%a: Failed to set memory attributes\n", __FUNCTION__));
> -    gDS->RemoveMemorySpace (AlignedAddress, SIZE_4KB);
> -    return Status;
> +    goto ErrorSetHostMemorySpace;
> +  }
> +
> +  //
> +  // In case a clock feeding the SPI interface is always on, skip its
> +  // configuration for Runtime.
> +  //
> +  if (Slave->HostClockFixed) {
> +    return EFI_SUCCESS;
> +  }
> +
> +  //
> +  // Make sure about an alignment of the memory space needed for clock enabling.
> +  // Add one aligned page of memory space which covers the clock enabling
> +  // register.
> +  //
> +  ClockEnableAlignedAddress = Slave->HostClockEnableRegister & ~(SIZE_4KB - 1);
> +
> +  Status = gDS->AddMemorySpace (EfiGcdMemoryTypeMemoryMappedIo,
> +                  ClockEnableAlignedAddress,
> +                  SIZE_4KB,
> +                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_ERROR, "%a: Failed to add memory space\n", __FUNCTION__));
> +    goto ErrorSetHostMemorySpace;
> +  }
> +
> +  Status = gDS->SetMemorySpaceAttributes (ClockEnableAlignedAddress,
> +                  SIZE_4KB,
> +                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_ERROR, "%a: Failed to set memory attributes\n", __FUNCTION__));
> +    goto ErrorSetClockMemorySpace;
>    }
>
>    return EFI_SUCCESS;
> +
> +ErrorSetClockMemorySpace:
> +  gDS->RemoveMemorySpace (ClockEnableAlignedAddress, SIZE_4KB);
> +
> +ErrorSetHostMemorySpace:
> +  gDS->RemoveMemorySpace (AlignedAddress, SIZE_4KB);
> +
> +  return Status;
>  }
>
>  STATIC
> @@ -393,6 +451,7 @@ SpiMasterInitProtocol (
>    SpiMasterProtocol->Transfer    = MvSpiTransfer;
>    SpiMasterProtocol->ReadWrite   = MvSpiReadWrite;
>    SpiMasterProtocol->ConfigRuntime = MvSpiConfigRuntime;
> +  SpiMasterProtocol->ControllerPowerOn = MvSpiControllerPowerOn;
>
>    return EFI_SUCCESS;
>  }
> --
> 2.7.4
>