\r
Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>\r
Copyright (C) 2013, Red Hat, Inc.\r
+ Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>\r
\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
-STATIC BOOLEAN mQemuFwCfgSupported = FALSE;\r
+#include "QemuFwCfgLibInternal.h"\r
\r
\r
/**\r
- Reads an 8-bit I/O port fifo into a block of memory.\r
-\r
- Reads the 8-bit I/O fifo port specified by Port.\r
-\r
- The port is read Count times, and the read data is\r
- stored in the provided Buffer.\r
-\r
- This function must guarantee that all I/O read and write operations are\r
- serialized.\r
-\r
- If 8-bit I/O port operations are not supported, then ASSERT().\r
+ Selects a firmware configuration item for reading.\r
+ \r
+ Following this call, any data read from this item will start from\r
+ the beginning of the configuration item's data.\r
\r
- @param Port The I/O port to read.\r
- @param Count The number of times to read I/O port.\r
- @param Buffer The buffer to store the read data into.\r
+ @param[in] QemuFwCfgItem - Firmware Configuration item to read\r
\r
**/\r
VOID\r
EFIAPI\r
-IoReadFifo8 (\r
- IN UINTN Port,\r
- IN UINTN Count,\r
- OUT VOID *Buffer\r
- );\r
+QemuFwCfgSelectItem (\r
+ IN FIRMWARE_CONFIG_ITEM QemuFwCfgItem\r
+ )\r
+{\r
+ DEBUG ((EFI_D_INFO, "Select Item: 0x%x\n", (UINT16)(UINTN) QemuFwCfgItem));\r
+ IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)(UINTN) QemuFwCfgItem);\r
+}\r
+\r
\r
/**\r
- Writes an 8-bit I/O port fifo from a block of memory.\r
+ Transfer an array of bytes, or skip a number of bytes, using the DMA\r
+ interface.\r
\r
- Writes the 8-bit I/O fifo port specified by Port.\r
+ @param[in] Size Size in bytes to transfer or skip.\r
\r
- The port is written Count times, and the data are obtained\r
- from the provided Buffer.\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
- This function must guarantee that all I/O read and write operations are\r
- serialized.\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
- If 8-bit I/O port operations are not supported, then ASSERT().\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
- @param Port The I/O port to read.\r
- @param Count The number of times to read I/O port.\r
- @param Buffer The buffer to store the read data into.\r
+ //\r
+ // Allocate SEV DMA buffer\r
+ //\r
+ NumPages = (UINT32)EFI_SIZE_TO_PAGES (TotalSize);\r
+ InternalQemuFwCfgSevDmaAllocateBuffer (&BounceBuffer, NumPages);\r
\r
-**/\r
-VOID\r
-EFIAPI\r
-IoWriteFifo8 (\r
- IN UINTN Port,\r
- IN UINTN Count,\r
- OUT VOID *Buffer\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
-/**\r
- Returns a boolean indicating if the firmware configuration interface\r
- is available or not.\r
+ Access->Control = SwapBytes32 (Control);\r
+ Access->Length = SwapBytes32 (Size);\r
+ Access->Address = SwapBytes64 ((UINTN)DmaBuffer);\r
\r
- This function may change fw_cfg state.\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
- @retval TRUE The interface is available\r
- @retval FALSE The interface is not available\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
-BOOLEAN\r
-EFIAPI\r
-QemuFwCfgIsAvailable (\r
- VOID\r
- )\r
-{\r
- return InternalQemuFwCfgIsAvailable ();\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
- Selects a firmware configuration item for reading.\r
- \r
- Following this call, any data read from this item will start from\r
- the beginning of the configuration item's data.\r
+ //\r
+ // After a read, the caller will want to use Buffer.\r
+ //\r
+ MemoryFence ();\r
\r
- @param[in] QemuFwCfgItem - Firmware Configuration item to read\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
-**/\r
-VOID\r
-EFIAPI\r
-QemuFwCfgSelectItem (\r
- IN FIRMWARE_CONFIG_ITEM QemuFwCfgItem\r
- )\r
-{\r
- DEBUG ((EFI_D_INFO, "Select Item: 0x%x\n", (UINT16)(UINTN) QemuFwCfgItem));\r
- IoWrite16 (0x510, (UINT16)(UINTN) QemuFwCfgItem);\r
+ InternalQemuFwCfgSevDmaFreeBuffer (BounceBuffer, NumPages);\r
+ }\r
}\r
\r
\r
IN VOID *Buffer OPTIONAL\r
)\r
{\r
- IoReadFifo8 (0x511, Size, Buffer);\r
+ if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
+ InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, FW_CFG_DMA_CTL_READ);\r
+ return;\r
+ }\r
+ IoReadFifo8 (FW_CFG_IO_DATA, Size, Buffer);\r
}\r
\r
\r
)\r
{\r
if (InternalQemuFwCfgIsAvailable ()) {\r
- IoWriteFifo8 (0x511, Size, Buffer);\r
+ if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
+ InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, FW_CFG_DMA_CTL_WRITE);\r
+ return;\r
+ }\r
+ IoWriteFifo8 (FW_CFG_IO_DATA, Size, Buffer);\r
+ }\r
+}\r
+\r
+\r
+/**\r
+ Skip bytes in the firmware configuration item.\r
+\r
+ Increase the offset of the firmware configuration item without transferring\r
+ bytes between the item and a caller-provided buffer. Subsequent read, write\r
+ or skip operations will commence at the increased offset.\r
+\r
+ @param[in] Size Number of bytes to skip.\r
+**/\r
+VOID\r
+EFIAPI\r
+QemuFwCfgSkipBytes (\r
+ IN UINTN Size\r
+ )\r
+{\r
+ UINTN ChunkSize;\r
+ UINT8 SkipBuffer[256];\r
+\r
+ if (!InternalQemuFwCfgIsAvailable ()) {\r
+ return;\r
+ }\r
+\r
+ if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
+ InternalQemuFwCfgDmaBytes ((UINT32)Size, NULL, FW_CFG_DMA_CTL_SKIP);\r
+ return;\r
+ }\r
+\r
+ //\r
+ // Emulate the skip by reading data in chunks, and throwing it away. The\r
+ // implementation below is suitable even for phases where RAM or dynamic\r
+ // allocation is not available or appropriate. It also doesn't affect the\r
+ // static data footprint for client modules. Large skips are not expected,\r
+ // therefore this fallback is not performance critical. The size of\r
+ // SkipBuffer is thought not to exert a large pressure on the stack in any\r
+ // phase.\r
+ //\r
+ while (Size > 0) {\r
+ ChunkSize = MIN (Size, sizeof SkipBuffer);\r
+ IoReadFifo8 (FW_CFG_IO_DATA, ChunkSize, SkipBuffer);\r
+ Size -= ChunkSize;\r
}\r
}\r
\r
}\r
\r
\r
-RETURN_STATUS\r
-EFIAPI\r
-QemuFwCfgInitialize (\r
- VOID\r
- )\r
-{\r
- UINT32 Signature;\r
- UINT32 Revision;\r
-\r
- //\r
- // Enable the access routines while probing to see if it is supported.\r
- //\r
- mQemuFwCfgSupported = TRUE;\r
-\r
- QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r
- Signature = QemuFwCfgRead32 ();\r
- DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));\r
- QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r
- Revision = QemuFwCfgRead32 ();\r
- DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));\r
- if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r
- (Revision < 1)\r
- ) {\r
- DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));\r
- mQemuFwCfgSupported = FALSE;\r
- return RETURN_SUCCESS;\r
- }\r
-\r
- DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));\r
- return RETURN_SUCCESS;\r
-}\r
-\r
-\r
/**\r
Find the configuration item corresponding to the firmware configuration file.\r
\r
UINT32 FileSize;\r
UINT16 FileSelect;\r
UINT16 FileReserved;\r
- CHAR8 FName[56];\r
+ CHAR8 FName[QEMU_FW_CFG_FNAME_SIZE];\r
\r
FileSize = QemuFwCfgRead32 ();\r
FileSelect = QemuFwCfgRead16 ();\r
FileReserved = QemuFwCfgRead16 ();\r
+ (VOID) FileReserved; /* Force a do-nothing reference. */\r
InternalQemuFwCfgReadBytes (sizeof (FName), FName);\r
\r
if (AsciiStrCmp (Name, FName) == 0) {\r
\r
return RETURN_NOT_FOUND;\r
}\r
-\r
-\r
-/**\r
- Returns a boolean indicating if the firmware configuration interface is\r
- available for library-internal purposes.\r
-\r
- This function never changes fw_cfg state.\r
-\r
- @retval TRUE The interface is available internally.\r
- @retval FALSE The interface is not available internally.\r
-**/\r
-BOOLEAN\r
-EFIAPI\r
-InternalQemuFwCfgIsAvailable (\r
- VOID\r
- )\r
-{\r
- return mQemuFwCfgSupported;\r
-}\r
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