[PATCH] EmbeddedPkg/MmcDxe: Align the ExtCSD buffer

[Jun Nie <jun.nie@linaro.org>]

ExtCSD structure may be read via DMA. So align it to
page to avoid data corruption.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
 EmbeddedPkg/Universal/MmcDxe/Mmc.h               |  2 +-
 EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/EmbeddedPkg/Universal/MmcDxe/Mmc.h b/EmbeddedPkg/Universal/MmcDxe/Mmc.h
index 8a7d5a3..f3e56ff 100644
--- a/EmbeddedPkg/Universal/MmcDxe/Mmc.h
+++ b/EmbeddedPkg/Universal/MmcDxe/Mmc.h
@@ -319,7 +319,7 @@ typedef struct  {
   OCR       OCRData;
   CID       CIDData;
   CSD       CSDData;
-  ECSD      ECSDData;                         // MMC V4 extended card specific
+  ECSD      *ECSDData;                         // MMC V4 extended card specific
 } CARD_INFO;
 
 typedef struct _MMC_HOST_INSTANCE {
diff --git a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
index c28207e..6bb65c3 100644
--- a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
+++ b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c
@@ -13,6 +13,7 @@
 **/
 
 #include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
 #include <Library/TimerLib.h>
 
 #include "Mmc.h"
@@ -210,12 +211,16 @@ EmmcIdentificationMode (
   }
 
   // Fetch ECSD
+  MmcHostInstance->CardInfo.ECSDData = AllocatePages (1);
+  if (MmcHostInstance->CardInfo.ECSDData == NULL) {
+    return EFI_BUFFER_TOO_SMALL;
+  }
   Status = Host->SendCommand (Host, MMC_CMD8, 0);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "EmmcIdentificationMode(): ECSD fetch error, Status=%r.\n", Status));
   }
 
-  Status = Host->ReadBlockData (Host, 0, 512, (UINT32 *)&(MmcHostInstance->CardInfo.ECSDData));
+  Status = Host->ReadBlockData (Host, 0, 512, (UINT32 *)MmcHostInstance->CardInfo.ECSDData);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "EmmcIdentificationMode(): ECSD read error, Status=%r.\n", Status));
     return Status;
@@ -237,7 +242,7 @@ EmmcIdentificationMode (
   Media->LogicalBlocksPerPhysicalBlock = 1;
   Media->IoAlign = 4;
   // Compute last block using bits [215:212] of the ECSD
-  Media->LastBlock = MmcHostInstance->CardInfo.ECSDData.SECTOR_COUNT - 1; // eMMC isn't supposed to report this for
+  Media->LastBlock = MmcHostInstance->CardInfo.ECSDData->SECTOR_COUNT - 1; // eMMC isn't supposed to report this for
   // Cards <2GB in size, but the model does.
 
   // Setup card type
@@ -258,7 +263,7 @@ InitializeEmmcDevice (
   UINT32     TimingMode[4] = {EMMCHS52DDR1V2, EMMCHS52DDR1V8, EMMCHS52, EMMCHS26};
 
   Host  = MmcHostInstance->MmcHost;
-  ECSDData = &MmcHostInstance->CardInfo.ECSDData;
+  ECSDData = MmcHostInstance->CardInfo.ECSDData;
   if (ECSDData->DEVICE_TYPE == EMMCBACKWARD)
     return EFI_SUCCESS;
 
-- 
1.9.1