[PATCH 2/7] MdeModulePkg/EhciDxe: 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/EhciDxe/Ehci.c      | 22 +++++++++++++++++++-
 MdeModulePkg/Bus/Pci/EhciDxe/Ehci.h      |  2 ++
 MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c |  2 +-
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
index 4e9e05f0e431..e4c7e59526de 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
@@ -89,7 +89,7 @@ EhcGetCapability (
 
   *MaxSpeed       = EFI_USB_SPEED_HIGH;
   *PortNumber     = (UINT8) (Ehc->HcStructParams & HCSP_NPORTS);
-  *Is64BitCapable = (UINT8) (Ehc->HcCapParams & HCCP_64BIT);
+  *Is64BitCapable = (UINT8) Ehc->Support64BitDma;
 
   DEBUG ((EFI_D_INFO, "EhcGetCapability: %d ports, 64 bit %d\n", *PortNumber, *Is64BitCapable));
 
@@ -1877,6 +1877,26 @@ EhcDriverBindingStart (
     goto CLOSE_PCIIO;
   }
 
+  //
+  // Enable 64-bit DMA support in the PCI layer if this controller
+  // supports it.
+  //
+  if ((Ehc->HcCapParams & HCCP_64BIT) != 0) {
+    Status = PciIo->Attributes (
+                      PciIo,
+                      EfiPciIoAttributeOperationEnable,
+                      EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE,
+                      NULL
+                      );
+    if (!EFI_ERROR (Status)) {
+      Ehc->Support64BitDma = TRUE;
+    } else {
+      DEBUG ((EFI_D_WARN,
+        "EhcDriverBindingStart: failed to enable 64-bit DMA on 64-bit capable controller @ %p (%r)\n",
+        Controller, Status));
+    }
+  }
+
   Status = gBS->InstallProtocolInterface (
                   &Controller,
                   &gEfiUsb2HcProtocolGuid,
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.h b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.h
index 7177658092c3..be81bde40d9b 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.h
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.h
@@ -173,6 +173,8 @@ struct _USB2_HC_DEV {
   UINT16                    DebugPortOffset; // The offset of debug port mmio register
   UINT8                     DebugPortBarNum; // The bar number of debug port mmio register
   UINT8                     DebugPortNum;    // The port number of usb debug port
+
+  BOOLEAN                   Support64BitDma; // Whether 64 bit DMA may be used with this device
 };
 
 
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
index 5594e6699ea6..036c00b32b40 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
@@ -178,7 +178,7 @@ EhcInitSched (
   //
   Ehc->MemPool = UsbHcInitMemPool (
                    PciIo,
-                   EHC_BIT_IS_SET (Ehc->HcCapParams, HCCP_64BIT),
+                   Ehc->Support64BitDma,
                    EHC_HIGH_32BIT (PhyAddr)
                    );
 
-- 
2.7.4