OvmfPkg/LsiScsiDxe: Map DMA buffer

Map DMA buffer and perpare for the implementation of LsiScsiPassThru().

v2:
  - Replace 0x10000 with SIZE_64KB macro for the DMA buffer data array
  - Remove DUAL_ADDRESS_CYCLE from PciIo since we don't really need
    64-bit DMA address

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200717061130.8881-9-glin@suse.com>

OvmfPkg/LsiScsiDxe/LsiScsi.c

@@ -356,6 +356,8 @@ LsiScsiControllerStart (
 {
   EFI_STATUS           Status;
   LSI_SCSI_DEV         *Dev;
+  UINTN                Pages;
+  UINTN                BytesMapped;
 
   Dev = AllocateZeroPool (sizeof (*Dev));
   if (Dev == NULL) {
@@ -411,11 +413,45 @@ LsiScsiControllerStart (
     goto CloseProtocol;
   }
 
-  Status = LsiScsiReset (Dev);
+  //
+  // Create buffers for data transfer
+  //
+  Pages = EFI_SIZE_TO_PAGES (sizeof (*Dev->Dma));
+  Status = Dev->PciIo->AllocateBuffer (
+                         Dev->PciIo,
+                         AllocateAnyPages,
+                         EfiBootServicesData,
+                         Pages,
+                         (VOID **)&Dev->Dma,
+                         EFI_PCI_ATTRIBUTE_MEMORY_CACHED
+                         );
   if (EFI_ERROR (Status)) {
     goto RestoreAttributes;
   }
 
+  BytesMapped = EFI_PAGES_TO_SIZE (Pages);
+  Status = Dev->PciIo->Map (
+                         Dev->PciIo,
+                         EfiPciIoOperationBusMasterCommonBuffer,
+                         Dev->Dma,
+                         &BytesMapped,
+                         &Dev->DmaPhysical,
+                         &Dev->DmaMapping
+                         );
+  if (EFI_ERROR (Status)) {
+    goto FreeBuffer;
+  }
+
+  if (BytesMapped != EFI_PAGES_TO_SIZE (Pages)) {
+    Status = EFI_OUT_OF_RESOURCES;
+    goto Unmap;
+  }
+
+  Status = LsiScsiReset (Dev);
+  if (EFI_ERROR (Status)) {
+    goto Unmap;
+  }
+
   Status = gBS->CreateEvent (
                   EVT_SIGNAL_EXIT_BOOT_SERVICES,
                   TPL_CALLBACK,
@@ -462,6 +498,19 @@ CloseExitBoot:
 UninitDev:
   LsiScsiReset (Dev);
 
+Unmap:
+  Dev->PciIo->Unmap (
+                Dev->PciIo,
+                Dev->DmaMapping
+                );
+
+FreeBuffer:
+  Dev->PciIo->FreeBuffer (
+                Dev->PciIo,
+                Pages,
+                Dev->Dma
+                );
+
 RestoreAttributes:
   Dev->PciIo->Attributes (
                 Dev->PciIo,
@@ -524,6 +573,17 @@ LsiScsiControllerStop (
 
   LsiScsiReset (Dev);
 
+  Dev->PciIo->Unmap (
+                Dev->PciIo,
+                Dev->DmaMapping
+                );
+
+  Dev->PciIo->FreeBuffer (
+                Dev->PciIo,
+                EFI_SIZE_TO_PAGES (sizeof (*Dev->Dma)),
+                Dev->Dma
+                );
+
   Dev->PciIo->Attributes (
                 Dev->PciIo,
                 EfiPciIoAttributeOperationSet,

OvmfPkg/LsiScsiDxe/LsiScsi.h

@@ -12,6 +12,17 @@
 #ifndef _LSI_SCSI_DXE_H_
 #define _LSI_SCSI_DXE_H_
 
+typedef struct {
+  //
+  // Allocate 64KB for read/write buffer. It seems sufficient for the common
+  // boot scenarios.
+  //
+  // NOTE: The number of bytes for data transmission is bounded by DMA Byte
+  //       Count (DBC), a 24-bit register, so the maximum is 0xFFFFFF (16MB-1).
+  //
+  UINT8                           Data[SIZE_64KB];
+} LSI_SCSI_DMA_BUFFER;
+
 typedef struct {
   UINT32                          Signature;
   UINT64                          OrigPciAttrs;
@@ -19,6 +30,9 @@ typedef struct {
   EFI_PCI_IO_PROTOCOL             *PciIo;
   UINT8                           MaxTarget;
   UINT8                           MaxLun;
+  LSI_SCSI_DMA_BUFFER             *Dma;
+  EFI_PHYSICAL_ADDRESS            DmaPhysical;
+  VOID                            *DmaMapping;
   EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;
   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;
 } LSI_SCSI_DEV;