#include <Protocol/IoMmu.h>\r
\r
#include <Library/BaseLib.h>\r
+#include <Library/IoLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
STATIC BOOLEAN mQemuFwCfgDmaSupported;\r
\r
STATIC EDKII_IOMMU_PROTOCOL *mIoMmuProtocol;\r
-/**\r
-\r
- Returns a boolean indicating whether SEV is enabled\r
-\r
- @retval TRUE SEV is enabled\r
- @retval FALSE SEV is disabled\r
-**/\r
-BOOLEAN\r
-InternalQemuFwCfgSevIsEnabled (\r
- VOID\r
- )\r
-{\r
- return MemEncryptSevIsEnabled ();\r
-}\r
\r
/**\r
Returns a boolean indicating if the firmware configuration interface\r
// IoMmuDxe driver must have installed the IOMMU protocol. If we are not\r
// able to locate the protocol then something must have gone wrong.\r
//\r
- Status = gBS->LocateProtocol (&gEdkiiIoMmuProtocolGuid, NULL, (VOID **)&mIoMmuProtocol);\r
+ Status = gBS->LocateProtocol (&gEdkiiIoMmuProtocolGuid, NULL,\r
+ (VOID **)&mIoMmuProtocol);\r
if (EFI_ERROR (Status)) {\r
DEBUG ((DEBUG_ERROR,\r
"QemuFwCfgSevDma %a:%a Failed to locate IOMMU protocol.\n",\r
}\r
\r
/**\r
- Allocate a bounce buffer for SEV DMA.\r
-\r
- @param[in] NumPage Number of pages.\r
- @param[out] Buffer Allocated DMA Buffer pointer\r
+ Function is used for allocating a bi-directional FW_CFG_DMA_ACCESS used\r
+ between Host and device to exchange the information. The buffer must be free'd\r
+ using FreeFwCfgDmaAccessBuffer ().\r
\r
**/\r
+STATIC\r
VOID\r
-InternalQemuFwCfgSevDmaAllocateBuffer (\r
- OUT VOID **Buffer,\r
- IN UINT32 NumPages\r
+AllocFwCfgDmaAccessBuffer (\r
+ OUT VOID **Access,\r
+ OUT VOID **MapInfo\r
)\r
{\r
- EFI_STATUS Status;\r
+ UINTN Size;\r
+ UINTN NumPages;\r
+ EFI_STATUS Status;\r
+ VOID *HostAddress;\r
+ EFI_PHYSICAL_ADDRESS DmaAddress;\r
+ VOID *Mapping;\r
\r
- ASSERT (mIoMmuProtocol != NULL);\r
+ Size = sizeof (FW_CFG_DMA_ACCESS);\r
+ NumPages = EFI_SIZE_TO_PAGES (Size);\r
\r
+ //\r
+ // As per UEFI spec, in order to map a host address with\r
+ // BusMasterCommomBuffer64, the buffer must be allocated using the IOMMU\r
+ // AllocateBuffer()\r
+ //\r
Status = mIoMmuProtocol->AllocateBuffer (\r
- mIoMmuProtocol,\r
- 0,\r
- EfiBootServicesData,\r
- NumPages,\r
- Buffer,\r
- EDKII_IOMMU_ATTRIBUTE_MEMORY_CACHED\r
- );\r
+ mIoMmuProtocol,\r
+ AllocateAnyPages,\r
+ EfiBootServicesData,\r
+ NumPages,\r
+ &HostAddress,\r
+ EDKII_IOMMU_ATTRIBUTE_DUAL_ADDRESS_CYCLE\r
+ );\r
if (EFI_ERROR (Status)) {\r
DEBUG ((DEBUG_ERROR,\r
- "%a:%a failed to allocate %u pages\n", gEfiCallerBaseName, __FUNCTION__,\r
- NumPages));\r
+ "%a:%a failed to allocate FW_CFG_DMA_ACCESS\n", gEfiCallerBaseName,\r
+ __FUNCTION__));\r
ASSERT (FALSE);\r
CpuDeadLoop ();\r
}\r
\r
- DEBUG ((DEBUG_VERBOSE,\r
- "%a:%a buffer 0x%Lx Pages %u\n", gEfiCallerBaseName, __FUNCTION__,\r
- (UINT64)(UINTN)Buffer, NumPages));\r
+ //\r
+ // Map the host buffer with BusMasterCommonBuffer64\r
+ //\r
+ Status = mIoMmuProtocol->Map (\r
+ mIoMmuProtocol,\r
+ EdkiiIoMmuOperationBusMasterCommonBuffer64,\r
+ HostAddress,\r
+ &Size,\r
+ &DmaAddress,\r
+ &Mapping\r
+ );\r
+ if (EFI_ERROR (Status)) {\r
+ mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, HostAddress);\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to Map() FW_CFG_DMA_ACCESS\n", gEfiCallerBaseName,\r
+ __FUNCTION__));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
+\r
+ if (Size < sizeof (FW_CFG_DMA_ACCESS)) {\r
+ mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
+ mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, HostAddress);\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to Map() - requested 0x%Lx got 0x%Lx\n", gEfiCallerBaseName,\r
+ __FUNCTION__, (UINT64)sizeof (FW_CFG_DMA_ACCESS), (UINT64)Size));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
+\r
+ *Access = HostAddress;\r
+ *MapInfo = Mapping;\r
}\r
\r
/**\r
- Free the DMA buffer allocated using InternalQemuFwCfgSevDmaAllocateBuffer\r
+ Function is to used for freeing the Access buffer allocated using\r
+ AllocFwCfgDmaAccessBuffer()\r
+\r
+**/\r
+STATIC\r
+VOID\r
+FreeFwCfgDmaAccessBuffer (\r
+ IN VOID *Access,\r
+ IN VOID *Mapping\r
+ )\r
+{\r
+ UINTN NumPages;\r
+ EFI_STATUS Status;\r
+\r
+ NumPages = EFI_SIZE_TO_PAGES (sizeof (FW_CFG_DMA_ACCESS));\r
\r
- @param[in] NumPage Number of pages.\r
- @param[in] Buffer DMA Buffer pointer\r
+ Status = mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
+ if (EFI_ERROR (Status)) {\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to UnMap() Mapping 0x%Lx\n", gEfiCallerBaseName,\r
+ __FUNCTION__, (UINT64)(UINTN)Mapping));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
+\r
+ Status = mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, Access);\r
+ if (EFI_ERROR (Status)) {\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to Free() 0x%Lx\n", gEfiCallerBaseName, __FUNCTION__,\r
+ (UINT64)(UINTN)Access));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
+}\r
+\r
+/**\r
+ Function is used for mapping host address to device address. The buffer must\r
+ be unmapped with UnmapDmaDataBuffer ().\r
\r
**/\r
+STATIC\r
VOID\r
-InternalQemuFwCfgSevDmaFreeBuffer (\r
- IN VOID *Buffer,\r
- IN UINT32 NumPages\r
+MapFwCfgDmaDataBuffer (\r
+ IN BOOLEAN IsWrite,\r
+ IN VOID *HostAddress,\r
+ IN UINT32 Size,\r
+ OUT EFI_PHYSICAL_ADDRESS *DeviceAddress,\r
+ OUT VOID **MapInfo\r
)\r
{\r
- EFI_STATUS Status;\r
+ EFI_STATUS Status;\r
+ UINTN NumberOfBytes;\r
+ VOID *Mapping;\r
+ EFI_PHYSICAL_ADDRESS PhysicalAddress;\r
+\r
+ NumberOfBytes = Size;\r
+ Status = mIoMmuProtocol->Map (\r
+ mIoMmuProtocol,\r
+ (IsWrite ?\r
+ EdkiiIoMmuOperationBusMasterRead64 :\r
+ EdkiiIoMmuOperationBusMasterWrite64),\r
+ HostAddress,\r
+ &NumberOfBytes,\r
+ &PhysicalAddress,\r
+ &Mapping\r
+ );\r
+ if (EFI_ERROR (Status)) {\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to Map() Address 0x%Lx Size 0x%Lx\n", gEfiCallerBaseName,\r
+ __FUNCTION__, (UINT64)(UINTN)HostAddress, (UINT64)Size));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
\r
- ASSERT (mIoMmuProtocol != NULL);\r
+ if (NumberOfBytes < Size) {\r
+ mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
+ DEBUG ((DEBUG_ERROR,\r
+ "%a:%a failed to Map() - requested 0x%x got 0x%Lx\n", gEfiCallerBaseName,\r
+ __FUNCTION__, Size, (UINT64)NumberOfBytes));\r
+ ASSERT (FALSE);\r
+ CpuDeadLoop ();\r
+ }\r
\r
- Status = mIoMmuProtocol->FreeBuffer (\r
- mIoMmuProtocol,\r
- NumPages,\r
- Buffer\r
- );\r
+ *DeviceAddress = PhysicalAddress;\r
+ *MapInfo = Mapping;\r
+}\r
+\r
+STATIC\r
+VOID\r
+UnmapFwCfgDmaDataBuffer (\r
+ IN VOID *Mapping\r
+ )\r
+{\r
+ EFI_STATUS Status;\r
+\r
+ Status = mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
if (EFI_ERROR (Status)) {\r
DEBUG ((DEBUG_ERROR,\r
- "%a:%a failed to free buffer 0x%Lx pages %u\n", gEfiCallerBaseName,\r
- __FUNCTION__, (UINT64)(UINTN)Buffer, NumPages));\r
+ "%a:%a failed to UnMap() Mapping 0x%Lx\n", gEfiCallerBaseName,\r
+ __FUNCTION__, (UINT64)(UINTN)Mapping));\r
ASSERT (FALSE);\r
CpuDeadLoop ();\r
}\r
+}\r
\r
- DEBUG ((DEBUG_VERBOSE,\r
- "%a:%a buffer 0x%Lx Pages %u\n", gEfiCallerBaseName,__FUNCTION__,\r
- (UINT64)(UINTN)Buffer, NumPages));\r
+/**\r
+ Transfer an array of bytes, or skip a number of bytes, using the DMA\r
+ interface.\r
+\r
+ @param[in] Size Size in bytes to transfer or skip.\r
+\r
+ @param[in,out] Buffer Buffer to read data into or write data from. Ignored,\r
+ and may be NULL, if Size is zero, or Control is\r
+ FW_CFG_DMA_CTL_SKIP.\r
+\r
+ @param[in] Control One of the following:\r
+ FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r
+ FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer.\r
+ FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.\r
+**/\r
+VOID\r
+InternalQemuFwCfgDmaBytes (\r
+ IN UINT32 Size,\r
+ IN OUT VOID *Buffer OPTIONAL,\r
+ IN UINT32 Control\r
+ )\r
+{\r
+ volatile FW_CFG_DMA_ACCESS LocalAccess;\r
+ volatile FW_CFG_DMA_ACCESS *Access;\r
+ UINT32 AccessHigh, AccessLow;\r
+ UINT32 Status;\r
+ VOID *AccessMapping, *DataMapping;\r
+ VOID *DataBuffer;\r
+\r
+ ASSERT (Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||\r
+ Control == FW_CFG_DMA_CTL_SKIP);\r
+\r
+ if (Size == 0) {\r
+ return;\r
+ }\r
+\r
+ Access = &LocalAccess;\r
+ AccessMapping = NULL;\r
+ DataMapping = NULL;\r
+ DataBuffer = Buffer;\r
+\r
+ //\r
+ // When SEV is enabled, map Buffer to DMA address before issuing the DMA\r
+ // request\r
+ //\r
+ if (MemEncryptSevIsEnabled ()) {\r
+ VOID *AccessBuffer;\r
+ EFI_PHYSICAL_ADDRESS DataBufferAddress;\r
+\r
+ //\r
+ // Allocate DMA Access buffer\r
+ //\r
+ AllocFwCfgDmaAccessBuffer (&AccessBuffer, &AccessMapping);\r
+\r
+ Access = AccessBuffer;\r
+\r
+ //\r
+ // Map actual data buffer\r
+ //\r
+ if (Control != FW_CFG_DMA_CTL_SKIP) {\r
+ MapFwCfgDmaDataBuffer (\r
+ Control == FW_CFG_DMA_CTL_WRITE,\r
+ Buffer,\r
+ Size,\r
+ &DataBufferAddress,\r
+ &DataMapping\r
+ );\r
+\r
+ DataBuffer = (VOID *) (UINTN) DataBufferAddress;\r
+ }\r
+ }\r
+\r
+ Access->Control = SwapBytes32 (Control);\r
+ Access->Length = SwapBytes32 (Size);\r
+ Access->Address = SwapBytes64 ((UINTN)DataBuffer);\r
+\r
+ //\r
+ // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
+ // write, from writes to Buffer by the caller.\r
+ //\r
+ MemoryFence ();\r
+\r
+ //\r
+ // Start the transfer.\r
+ //\r
+ AccessHigh = (UINT32)RShiftU64 ((UINTN)Access, 32);\r
+ AccessLow = (UINT32)(UINTN)Access;\r
+ IoWrite32 (FW_CFG_IO_DMA_ADDRESS, SwapBytes32 (AccessHigh));\r
+ IoWrite32 (FW_CFG_IO_DMA_ADDRESS + 4, SwapBytes32 (AccessLow));\r
+\r
+ //\r
+ // Don't look at Access.Control before starting the transfer.\r
+ //\r
+ MemoryFence ();\r
+\r
+ //\r
+ // Wait for the transfer to complete.\r
+ //\r
+ do {\r
+ Status = SwapBytes32 (Access->Control);\r
+ ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
+ } while (Status != 0);\r
+\r
+ //\r
+ // After a read, the caller will want to use Buffer.\r
+ //\r
+ MemoryFence ();\r
+\r
+ //\r
+ // If Access buffer was dynamically allocated then free it.\r
+ //\r
+ if (AccessMapping != NULL) {\r
+ FreeFwCfgDmaAccessBuffer ((VOID *)Access, AccessMapping);\r
+ }\r
+\r
+ //\r
+ // If DataBuffer was mapped then unmap it.\r
+ //\r
+ if (DataMapping != NULL) {\r
+ UnmapFwCfgDmaDataBuffer (DataMapping);\r
+ }\r
}\r
IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)(UINTN) QemuFwCfgItem);\r
}\r
\r
-\r
-/**\r
- Transfer an array of bytes, or skip a number of bytes, using the DMA\r
- interface.\r
-\r
- @param[in] Size Size in bytes to transfer or skip.\r
-\r
- @param[in,out] Buffer Buffer to read data into or write data from. Ignored,\r
- and may be NULL, if Size is zero, or Control is\r
- FW_CFG_DMA_CTL_SKIP.\r
-\r
- @param[in] Control One of the following:\r
- FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r
- FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer.\r
- FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.\r
-**/\r
-VOID\r
-InternalQemuFwCfgDmaBytes (\r
- IN UINT32 Size,\r
- IN OUT VOID *Buffer OPTIONAL,\r
- IN UINT32 Control\r
- )\r
-{\r
- volatile FW_CFG_DMA_ACCESS LocalAccess;\r
- volatile FW_CFG_DMA_ACCESS *Access;\r
- UINT32 AccessHigh, AccessLow;\r
- UINT32 Status;\r
- UINT32 NumPages;\r
- VOID *DmaBuffer, *BounceBuffer;\r
-\r
- ASSERT (Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||\r
- Control == FW_CFG_DMA_CTL_SKIP);\r
-\r
- if (Size == 0) {\r
- return;\r
- }\r
-\r
- //\r
- // set NumPages to suppress incorrect compiler/analyzer warnings\r
- //\r
- NumPages = 0;\r
-\r
- //\r
- // When SEV is enabled then allocate DMA bounce buffer\r
- //\r
- if (InternalQemuFwCfgSevIsEnabled ()) {\r
- UINTN TotalSize;\r
-\r
- TotalSize = sizeof (*Access);\r
- //\r
- // Skip operation does not need buffer\r
- //\r
- if (Control != FW_CFG_DMA_CTL_SKIP) {\r
- TotalSize += Size;\r
- }\r
-\r
- //\r
- // Allocate SEV DMA buffer\r
- //\r
- NumPages = (UINT32)EFI_SIZE_TO_PAGES (TotalSize);\r
- InternalQemuFwCfgSevDmaAllocateBuffer (&BounceBuffer, NumPages);\r
-\r
- Access = BounceBuffer;\r
- DmaBuffer = (UINT8*)BounceBuffer + sizeof (*Access);\r
-\r
- //\r
- // Decrypt data from encrypted guest buffer into DMA buffer\r
- //\r
- if (Control == FW_CFG_DMA_CTL_WRITE) {\r
- CopyMem (DmaBuffer, Buffer, Size);\r
- }\r
- } else {\r
- Access = &LocalAccess;\r
- DmaBuffer = Buffer;\r
- BounceBuffer = NULL;\r
- }\r
-\r
- Access->Control = SwapBytes32 (Control);\r
- Access->Length = SwapBytes32 (Size);\r
- Access->Address = SwapBytes64 ((UINTN)DmaBuffer);\r
-\r
- //\r
- // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
- // write, from writes to Buffer by the caller.\r
- //\r
- MemoryFence ();\r
-\r
- //\r
- // Start the transfer.\r
- //\r
- AccessHigh = (UINT32)RShiftU64 ((UINTN)Access, 32);\r
- AccessLow = (UINT32)(UINTN)Access;\r
- IoWrite32 (FW_CFG_IO_DMA_ADDRESS, SwapBytes32 (AccessHigh));\r
- IoWrite32 (FW_CFG_IO_DMA_ADDRESS + 4, SwapBytes32 (AccessLow));\r
-\r
- //\r
- // Don't look at Access.Control before starting the transfer.\r
- //\r
- MemoryFence ();\r
-\r
- //\r
- // Wait for the transfer to complete.\r
- //\r
- do {\r
- Status = SwapBytes32 (Access->Control);\r
- ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
- } while (Status != 0);\r
-\r
- //\r
- // After a read, the caller will want to use Buffer.\r
- //\r
- MemoryFence ();\r
-\r
- //\r
- // If Bounce buffer was allocated then copy the data into guest buffer and\r
- // free the bounce buffer\r
- //\r
- if (BounceBuffer != NULL) {\r
- //\r
- // Encrypt the data from DMA buffer into guest buffer\r
- //\r
- if (Control == FW_CFG_DMA_CTL_READ) {\r
- CopyMem (Buffer, DmaBuffer, Size);\r
- }\r
-\r
- InternalQemuFwCfgSevDmaFreeBuffer (BounceBuffer, NumPages);\r
- }\r
-}\r
-\r
-\r
/**\r
Reads firmware configuration bytes into a buffer\r
\r
**/\r
\r
#include <Library/BaseLib.h>\r
+#include <Library/IoLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/MemEncryptSevLib.h>\r
// (which need to allocate dynamic memory and allocating a PAGE size'd\r
// buffer can be challenge in PEI phase)\r
//\r
- if (InternalQemuFwCfgSevIsEnabled ()) {\r
+ if (MemEncryptSevIsEnabled ()) {\r
DEBUG ((DEBUG_INFO, "SEV: QemuFwCfg fallback to IO Port interface.\n"));\r
} else {\r
mQemuFwCfgDmaSupported = TRUE;\r
}\r
\r
/**\r
+ Transfer an array of bytes, or skip a number of bytes, using the DMA\r
+ interface.\r
\r
- Returns a boolean indicating whether SEV is enabled\r
+ @param[in] Size Size in bytes to transfer or skip.\r
\r
- @retval TRUE SEV is enabled\r
- @retval FALSE SEV is disabled\r
+ @param[in,out] Buffer Buffer to read data into or write data from. Ignored,\r
+ and may be NULL, if Size is zero, or Control is\r
+ FW_CFG_DMA_CTL_SKIP.\r
+\r
+ @param[in] Control One of the following:\r
+ FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r
+ FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer.\r
+ FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.\r
**/\r
-BOOLEAN\r
-InternalQemuFwCfgSevIsEnabled (\r
- VOID\r
+VOID\r
+InternalQemuFwCfgDmaBytes (\r
+ IN UINT32 Size,\r
+ IN OUT VOID *Buffer OPTIONAL,\r
+ IN UINT32 Control\r
)\r
{\r
- return MemEncryptSevIsEnabled ();\r
-}\r
+ volatile FW_CFG_DMA_ACCESS Access;\r
+ UINT32 AccessHigh, AccessLow;\r
+ UINT32 Status;\r
\r
-/**\r
- Allocate a bounce buffer for SEV DMA.\r
+ ASSERT (Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||\r
+ Control == FW_CFG_DMA_CTL_SKIP);\r
\r
- @param[in] NumPage Number of pages.\r
- @param[out] Buffer Allocated DMA Buffer pointer\r
+ if (Size == 0) {\r
+ return;\r
+ }\r
\r
-**/\r
-VOID\r
-InternalQemuFwCfgSevDmaAllocateBuffer (\r
- OUT VOID **Buffer,\r
- IN UINT32 NumPages\r
- )\r
-{\r
//\r
- // We should never reach here\r
+ // SEV does not support DMA operations in PEI stage, we should\r
+ // not have reached here.\r
//\r
- ASSERT (FALSE);\r
- CpuDeadLoop ();\r
-}\r
+ ASSERT (!MemEncryptSevIsEnabled ());\r
\r
-/**\r
- Free the DMA buffer allocated using InternalQemuFwCfgSevDmaAllocateBuffer\r
+ Access.Control = SwapBytes32 (Control);\r
+ Access.Length = SwapBytes32 (Size);\r
+ Access.Address = SwapBytes64 ((UINTN)Buffer);\r
\r
- @param[in] NumPage Number of pages.\r
- @param[in] Buffer DMA Buffer pointer\r
+ //\r
+ // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
+ // write, from writes to Buffer by the caller.\r
+ //\r
+ MemoryFence ();\r
+\r
+ //\r
+ // Start the transfer.\r
+ //\r
+ AccessHigh = (UINT32)RShiftU64 ((UINTN)&Access, 32);\r
+ AccessLow = (UINT32)(UINTN)&Access;\r
+ IoWrite32 (FW_CFG_IO_DMA_ADDRESS, SwapBytes32 (AccessHigh));\r
+ IoWrite32 (FW_CFG_IO_DMA_ADDRESS + 4, SwapBytes32 (AccessLow));\r
\r
-**/\r
-VOID\r
-InternalQemuFwCfgSevDmaFreeBuffer (\r
- IN VOID *Buffer,\r
- IN UINT32 NumPages\r
- )\r
-{\r
//\r
- // We should never reach here\r
+ // Don't look at Access.Control before starting the transfer.\r
//\r
- ASSERT (FALSE);\r
- CpuDeadLoop ();\r
+ MemoryFence ();\r
+\r
+ //\r
+ // Wait for the transfer to complete.\r
+ //\r
+ do {\r
+ Status = SwapBytes32 (Access.Control);\r
+ ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
+ } while (Status != 0);\r
+\r
+ //\r
+ // After a read, the caller will want to use Buffer.\r
+ //\r
+ MemoryFence ();\r
}\r
+\r
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