-\r
-/**\r
- Transfer an array of bytes using the DMA interface.\r
-\r
- @param[in] Size Size in bytes to transfer.\r
- @param[in,out] Buffer Buffer to read data into or write data from. May be\r
- NULL if Size is zero.\r
- @param[in] Write TRUE if writing to fw_cfg from Buffer, FALSE if\r
- reading from fw_cfg into Buffer.\r
-**/\r
-VOID\r
-InternalQemuFwCfgDmaBytes (\r
- IN UINT32 Size,\r
- IN OUT VOID *Buffer OPTIONAL,\r
- IN BOOLEAN Write\r
- )\r
-{\r
- volatile FW_CFG_DMA_ACCESS Access;\r
- UINT32 AccessHigh, AccessLow;\r
- UINT32 Status;\r
-\r
- if (Size == 0) {\r
- return;\r
- }\r
-\r
- Access.Control = SwapBytes32 (\r
- Write ? FW_CFG_DMA_CTL_WRITE : FW_CFG_DMA_CTL_READ\r
- );\r
- Access.Length = SwapBytes32 (Size);\r
- Access.Address = SwapBytes64 ((UINTN)Buffer);\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 (0x514, SwapBytes32 (AccessHigh));\r
- IoWrite32 (0x518, 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
-\r