CoherentDmaLib.c

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#include <Uefi.h>
#include <Library/DebugLib.h>
#include <Library/DmaLib.h>
#include <Library/MemoryAllocationLib.h>
 
STATIC
PHYSICAL_ADDRESS
HostToDeviceAddress (
  IN  VOID  *Address
  )
{
  return (PHYSICAL_ADDRESS)(UINTN)Address + PcdGet64 (PcdDmaDeviceOffset);
}
 
EFI_STATUS
EFIAPI
DmaMap (
  IN     DMA_MAP_OPERATION  Operation,
  IN     VOID               *HostAddress,
  IN OUT UINTN              *NumberOfBytes,
  OUT    PHYSICAL_ADDRESS   *DeviceAddress,
  OUT    VOID               **Mapping
  )
{
  if ((HostAddress == NULL) ||
      (NumberOfBytes == NULL) ||
      (DeviceAddress == NULL) ||
      (Mapping == NULL))
  {
    return EFI_INVALID_PARAMETER;
  }
 
  *DeviceAddress = HostToDeviceAddress (HostAddress);
  *Mapping       = NULL;
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
DmaUnmap (
  IN  VOID  *Mapping
  )
{
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
DmaAllocateBuffer (
  IN  EFI_MEMORY_TYPE  MemoryType,
  IN  UINTN            Pages,
  OUT VOID             **HostAddress
  )
{
  return DmaAllocateAlignedBuffer (MemoryType, Pages, 0, HostAddress);
}
 
EFI_STATUS
EFIAPI
DmaAllocateAlignedBuffer (
  IN  EFI_MEMORY_TYPE  MemoryType,
  IN  UINTN            Pages,
  IN  UINTN            Alignment,
  OUT VOID             **HostAddress
  )
{
  if (Alignment == 0) {
    Alignment = EFI_PAGE_SIZE;
  }
 
  if ((HostAddress == NULL) ||
      ((Alignment & (Alignment - 1)) != 0))
  {
    return EFI_INVALID_PARAMETER;
  }
 
  //
  // The only valid memory types are EfiBootServicesData and EfiRuntimeServicesData
  //
  if (MemoryType == EfiBootServicesData) {
    *HostAddress = AllocateAlignedPages (Pages, Alignment);
  } else if (MemoryType == EfiRuntimeServicesData) {
    *HostAddress = AllocateAlignedRuntimePages (Pages, Alignment);
  } else {
    return EFI_INVALID_PARAMETER;
  }
 
  if (*HostAddress == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
DmaFreeBuffer (
  IN  UINTN  Pages,
  IN  VOID   *HostAddress
  )
{
  if (HostAddress == NULL) {
    return EFI_INVALID_PARAMETER;
  }
 
  FreePages (HostAddress, Pages);
  return EFI_SUCCESS;
}