[PATCH 5/7] MdeModulePkg/XhciDxe: enable 64-bit PCI DMA

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

PCI controller drivers must set the EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE
attribute if the controller supports 64-bit DMA addressing.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c | 22 +++++++++++++++++++-
 MdeModulePkg/Bus/Pci/XhciDxe/Xhci.h |  2 ++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
index 4798bea86061..cdff1c3b8849 100644
--- a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
+++ b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
@@ -125,7 +125,7 @@ XhcGetCapability (
   Xhc             = XHC_FROM_THIS (This);
   *MaxSpeed       = EFI_USB_SPEED_SUPER;
   *PortNumber     = (UINT8) (Xhc->HcSParams1.Data.MaxPorts);
-  *Is64BitCapable = (UINT8) (Xhc->HcCParams.Data.Ac64);
+  *Is64BitCapable = (UINT8) Xhc->Support64BitDma;
   DEBUG ((EFI_D_INFO, "XhcGetCapability: %d ports, 64 bit %d\n", *PortNumber, *Is64BitCapable));
 
   gBS->RestoreTPL (OldTpl);
@@ -2020,6 +2020,26 @@ XhcDriverBindingStart (
     return EFI_OUT_OF_RESOURCES;
   }
 
+  //
+  // Enable 64-bit DMA support in the PCI layer if this controller
+  // supports it.
+  //
+  if ((Xhc->HcCParams.Data.Ac64) != 0) {
+    Status = PciIo->Attributes (
+                      PciIo,
+                      EfiPciIoAttributeOperationEnable,
+                      EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE,
+                      NULL
+                      );
+    if (!EFI_ERROR (Status)) {
+      Xhc->Support64BitDma = TRUE;
+    } else {
+      DEBUG ((EFI_D_WARN,
+        "XhcDriverBindingStart: failed to enable 64-bit DMA on 64-bit capable controller @ %p (%r)\n",
+        Controller, Status));
+    }
+  }
+
   XhcSetBiosOwnership (Xhc);
 
   XhcResetHC (Xhc, XHC_RESET_TIMEOUT);
diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.h b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.h
index 7999151b3fde..0f53bb0eff7c 100644
--- a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.h
+++ b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.h
@@ -256,6 +256,8 @@ struct _USB_XHCI_INSTANCE {
   // The array supports up to 255 devices, entry 0 is reserved and should not be used.
   //
   USB_DEV_CONTEXT           UsbDevContext[256];
+
+  BOOLEAN                   Support64BitDma; // Whether 64 bit DMA may be used with this device
 };
 
 
-- 
2.7.4