diff options
| -rw-r--r-- | OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c | 214 |
1 files changed, 76 insertions, 138 deletions
diff --git a/OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c b/OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c index 0a5c5d48c7..0343131a54 100644 --- a/OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c +++ b/OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c @@ -576,23 +576,20 @@ NorFlashWriteSingleBlock ( IN UINT8 *Buffer
)
{
- EFI_STATUS TempStatus;
- UINT32 Tmp;
- UINT32 TmpBuf;
- UINT32 WordToWrite;
- UINT32 Mask;
- BOOLEAN DoErase;
- UINTN BytesToWrite;
+ EFI_STATUS Status;
UINTN CurOffset;
- UINTN WordAddr;
UINTN BlockSize;
UINTN BlockAddress;
- UINTN PrevBlockAddress;
-
- PrevBlockAddress = 0;
+ UINT8 *OrigData;
DEBUG ((DEBUG_BLKIO, "NorFlashWriteSingleBlock(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Lba, Offset, *NumBytes, Buffer));
+ // Check we did get some memory. Buffer is BlockSize.
+ if (Instance->ShadowBuffer == NULL) {
+ DEBUG ((DEBUG_ERROR, "FvbWrite: ERROR - Buffer not ready\n"));
+ return EFI_DEVICE_ERROR;
+ }
+
// Cache the block size to avoid de-referencing pointers all the time
BlockSize = Instance->BlockSize;
@@ -612,148 +609,89 @@ NorFlashWriteSingleBlock ( return EFI_BAD_BUFFER_SIZE;
}
- // Pick 128bytes as a good start for word operations as opposed to erasing the
- // block and writing the data regardless if an erase is really needed.
- // It looks like most individual NV variable writes are smaller than 128bytes.
- if (*NumBytes <= 128) {
+ // Pick P30_MAX_BUFFER_SIZE_IN_BYTES (== 128 bytes) as a good start for word
+ // operations as opposed to erasing the block and writing the data regardless
+ // if an erase is really needed. It looks like most individual NV variable
+ // writes are smaller than 128 bytes.
+ // To avoid pathological cases were a 2 byte write is disregarded because it
+ // occurs right at a 128 byte buffered write alignment boundary, permit up to
+ // twice the max buffer size, and perform two writes if needed.
+ if ((*NumBytes + (Offset & BOUNDARY_OF_32_WORDS)) <= (2 * P30_MAX_BUFFER_SIZE_IN_BYTES)) {
// Check to see if we need to erase before programming the data into NOR.
// If the destination bits are only changing from 1s to 0s we can just write.
// After a block is erased all bits in the block is set to 1.
// If any byte requires us to erase we just give up and rewrite all of it.
- DoErase = FALSE;
- BytesToWrite = *NumBytes;
- CurOffset = Offset;
-
- while (BytesToWrite > 0) {
- // Read full word from NOR, splice as required. A word is the smallest
- // unit we can write.
- TempStatus = NorFlashRead (Instance, Lba, CurOffset & ~(0x3), sizeof (Tmp), &Tmp);
- if (EFI_ERROR (TempStatus)) {
- return EFI_DEVICE_ERROR;
- }
- // Physical address of word in NOR to write.
- WordAddr = (CurOffset & ~(0x3)) + GET_NOR_BLOCK_ADDRESS (
- Instance->RegionBaseAddress,
- Lba,
- BlockSize
- );
- // The word of data that is to be written.
- TmpBuf = *((UINT32 *)(Buffer + (*NumBytes - BytesToWrite)));
-
- // First do word aligned chunks.
- if ((CurOffset & 0x3) == 0) {
- if (BytesToWrite >= 4) {
- // Is the destination still in 'erased' state?
- if (~Tmp != 0) {
- // Check to see if we are only changing bits to zero.
- if ((Tmp ^ TmpBuf) & TmpBuf) {
- DoErase = TRUE;
- break;
- }
- }
-
- // Write this word to NOR
- WordToWrite = TmpBuf;
- CurOffset += sizeof (TmpBuf);
- BytesToWrite -= sizeof (TmpBuf);
- } else {
- // BytesToWrite < 4. Do small writes and left-overs
- Mask = ~((~0) << (BytesToWrite * 8));
- // Mask out the bytes we want.
- TmpBuf &= Mask;
- // Is the destination still in 'erased' state?
- if ((Tmp & Mask) != Mask) {
- // Check to see if we are only changing bits to zero.
- if ((Tmp ^ TmpBuf) & TmpBuf) {
- DoErase = TRUE;
- break;
- }
- }
-
- // Merge old and new data. Write merged word to NOR
- WordToWrite = (Tmp & ~Mask) | TmpBuf;
- CurOffset += BytesToWrite;
- BytesToWrite = 0;
- }
- } else {
- // Do multiple words, but starting unaligned.
- if (BytesToWrite > (4 - (CurOffset & 0x3))) {
- Mask = ((~0) << ((CurOffset & 0x3) * 8));
- // Mask out the bytes we want.
- TmpBuf &= Mask;
- // Is the destination still in 'erased' state?
- if ((Tmp & Mask) != Mask) {
- // Check to see if we are only changing bits to zero.
- if ((Tmp ^ TmpBuf) & TmpBuf) {
- DoErase = TRUE;
- break;
- }
- }
-
- // Merge old and new data. Write merged word to NOR
- WordToWrite = (Tmp & ~Mask) | TmpBuf;
- BytesToWrite -= (4 - (CurOffset & 0x3));
- CurOffset += (4 - (CurOffset & 0x3));
- } else {
- // Unaligned and fits in one word.
- Mask = (~((~0) << (BytesToWrite * 8))) << ((CurOffset & 0x3) * 8);
- // Mask out the bytes we want.
- TmpBuf = (TmpBuf << ((CurOffset & 0x3) * 8)) & Mask;
- // Is the destination still in 'erased' state?
- if ((Tmp & Mask) != Mask) {
- // Check to see if we are only changing bits to zero.
- if ((Tmp ^ TmpBuf) & TmpBuf) {
- DoErase = TRUE;
- break;
- }
- }
-
- // Merge old and new data. Write merged word to NOR
- WordToWrite = (Tmp & ~Mask) | TmpBuf;
- CurOffset += BytesToWrite;
- BytesToWrite = 0;
- }
+ // Read the old version of the data into the shadow buffer
+ Status = NorFlashRead (
+ Instance,
+ Lba,
+ Offset & ~BOUNDARY_OF_32_WORDS,
+ (*NumBytes | BOUNDARY_OF_32_WORDS) + 1,
+ Instance->ShadowBuffer
+ );
+ if (EFI_ERROR (Status)) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ // Make OrigData point to the start of the old version of the data inside
+ // the word aligned buffer
+ OrigData = Instance->ShadowBuffer + (Offset & BOUNDARY_OF_32_WORDS);
+
+ // Update the buffer containing the old version of the data with the new
+ // contents, while checking whether the old version had any bits cleared
+ // that we want to set. In that case, we will need to erase the block first.
+ for (CurOffset = 0; CurOffset < *NumBytes; CurOffset++) {
+ if (~OrigData[CurOffset] & Buffer[CurOffset]) {
+ goto DoErase;
}
- //
- // Write the word to NOR.
- //
+ OrigData[CurOffset] = Buffer[CurOffset];
+ }
- BlockAddress = GET_NOR_BLOCK_ADDRESS (Instance->RegionBaseAddress, Lba, BlockSize);
- if (BlockAddress != PrevBlockAddress) {
- TempStatus = NorFlashUnlockSingleBlockIfNecessary (Instance, BlockAddress);
- if (EFI_ERROR (TempStatus)) {
- return EFI_DEVICE_ERROR;
- }
+ //
+ // Write the updated buffer to NOR.
+ //
+ BlockAddress = GET_NOR_BLOCK_ADDRESS (Instance->RegionBaseAddress, Lba, BlockSize);
- PrevBlockAddress = BlockAddress;
- }
+ // Unlock the block if we have to
+ Status = NorFlashUnlockSingleBlockIfNecessary (Instance, BlockAddress);
+ if (EFI_ERROR (Status)) {
+ goto Exit;
+ }
- TempStatus = NorFlashWriteSingleWord (Instance, WordAddr, WordToWrite);
- // Put device back into Read Array mode
- SEND_NOR_COMMAND (Instance->DeviceBaseAddress, 0, P30_CMD_READ_ARRAY);
- if (EFI_ERROR (TempStatus)) {
- return EFI_DEVICE_ERROR;
- }
+ Status = NorFlashWriteBuffer (
+ Instance,
+ BlockAddress + (Offset & ~BOUNDARY_OF_32_WORDS),
+ P30_MAX_BUFFER_SIZE_IN_BYTES,
+ Instance->ShadowBuffer
+ );
+ if (EFI_ERROR (Status)) {
+ goto Exit;
}
- // Exit if we got here and could write all the data. Otherwise do the
- // Erase-Write cycle.
- if (!DoErase) {
- return EFI_SUCCESS;
+ if ((*NumBytes + (Offset & BOUNDARY_OF_32_WORDS)) > P30_MAX_BUFFER_SIZE_IN_BYTES) {
+ BlockAddress += P30_MAX_BUFFER_SIZE_IN_BYTES;
+
+ Status = NorFlashWriteBuffer (
+ Instance,
+ BlockAddress + (Offset & ~BOUNDARY_OF_32_WORDS),
+ P30_MAX_BUFFER_SIZE_IN_BYTES,
+ Instance->ShadowBuffer + P30_MAX_BUFFER_SIZE_IN_BYTES
+ );
}
- }
- // Check we did get some memory. Buffer is BlockSize.
- if (Instance->ShadowBuffer == NULL) {
- DEBUG ((DEBUG_ERROR, "FvbWrite: ERROR - Buffer not ready\n"));
- return EFI_DEVICE_ERROR;
+Exit:
+ // Put device back into Read Array mode
+ SEND_NOR_COMMAND (Instance->DeviceBaseAddress, 0, P30_CMD_READ_ARRAY);
+
+ return Status;
}
+DoErase:
// Read NOR Flash data into shadow buffer
- TempStatus = NorFlashReadBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
- if (EFI_ERROR (TempStatus)) {
+ Status = NorFlashReadBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
+ if (EFI_ERROR (Status)) {
// Return one of the pre-approved error statuses
return EFI_DEVICE_ERROR;
}
@@ -762,8 +700,8 @@ NorFlashWriteSingleBlock ( CopyMem ((VOID *)((UINTN)Instance->ShadowBuffer + Offset), Buffer, *NumBytes);
// Write the modified buffer back to the NorFlash
- TempStatus = NorFlashWriteBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
- if (EFI_ERROR (TempStatus)) {
+ Status = NorFlashWriteBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
+ if (EFI_ERROR (Status)) {
// Return one of the pre-approved error statuses
return EFI_DEVICE_ERROR;
}
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