[edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 10/12] PciBusDxe: New PCI feature Relax Ordering

["Javeed, Ashraf" <ashraf.javeed@intel.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2313

The code changes are made to enable the configuration of new PCI feature
Relax Ordering (OR), which enables the PCI function to initiate requests
if it does not require strong write ordering for its transactions; as per
the PCI Base Specification 4 Revision 1.

The code changes are made to configure only those PCI devices which are
requested to override by platform through the new PCI Platform protocol
interface for device-specific policies.

Signed-off-by: Ashraf Javeed <ashraf.javeed@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
---
 MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h             |  2 ++
 MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c  | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.h  | 26 ++++++++++++++++++++++++++
 MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 150 insertions(+)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
index 38abd20..9f017b7 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
@@ -82,6 +82,7 @@ typedef enum {
 #include "PciHotPlugSupport.h"
 #include "PciLib.h"
 #include "PciPlatformSupport.h"
+#include "PciFeatureSupport.h"
 
 #define VGABASE1  0x3B0
 #define VGALIMIT1 0x3BB
@@ -291,6 +292,7 @@ struct _PCI_IO_DEVICE {
   //
   UINT8                                     SetupMPS;
   UINT8                                     SetupMRRS;
+  PCI_FEATURE_POLICY                        SetupRO;
 };
 
 #define PCI_IO_DEVICE_FROM_PCI_IO_THIS(a) \
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
index 614285f..a60cb42 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
@@ -911,6 +911,81 @@ OverrideMaxReadReqSize (
   return Status;
 }
 
+/**
+  Overrides the PCI Device Control register Relax Order register field; if
+  the hardware value is different than the intended value.
+
+  @param  PciDevice             A pointer to the PCI_IO_DEVICE instance.
+
+  @retval EFI_SUCCESS           The data was read from or written to the PCI device.
+  @retval EFI_UNSUPPORTED       The address range specified by Offset, Width, and Count is not
+                                valid for the PCI configuration header of the PCI controller.
+  @retval EFI_INVALID_PARAMETER Buffer is NULL or Width is invalid.
+
+**/
+EFI_STATUS
+OverrideRelaxOrder (
+  IN PCI_IO_DEVICE          *PciDevice
+  )
+{
+  PCI_REG_PCIE_DEVICE_CONTROL PcieDev;
+  UINT32                      Offset;
+  EFI_STATUS                  Status;
+  EFI_TPL                     OldTpl;
+
+  PcieDev.Uint16 = 0;
+  Offset = PciDevice->PciExpressCapabilityOffset +
+               OFFSET_OF (PCI_CAPABILITY_PCIEXP, DeviceControl);
+  Status = PciDevice->PciIo.Pci.Read (
+                                  &PciDevice->PciIo,
+                                  EfiPciIoWidthUint16,
+                                  Offset,
+                                  1,
+                                  &PcieDev.Uint16
+                                );
+  if (EFI_ERROR(Status)){
+    DEBUG (( DEBUG_ERROR, "Unexpected DeviceControl register (0x%x) read error!",
+        Offset
+    ));
+    return Status;
+  }
+  if (PciDevice->SetupRO.Override
+      &&  PcieDev.Bits.RelaxedOrdering != PciDevice->SetupRO.Act
+      ) {
+    PcieDev.Bits.RelaxedOrdering = PciDevice->SetupRO.Act;
+    DEBUG (( DEBUG_INFO, "RO=%d,", PciDevice->SetupRO.Act));
+
+    //
+    // Raise TPL to high level to disable timer interrupt while the write operation completes
+    //
+    OldTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL);
+
+    Status = PciDevice->PciIo.Pci.Write (
+                                    &PciDevice->PciIo,
+                                    EfiPciIoWidthUint16,
+                                    Offset,
+                                    1,
+                                    &PcieDev.Uint16
+                                  );
+    //
+    // Restore TPL to its original level
+    //
+    gBS->RestoreTPL (OldTpl);
+
+    if (!EFI_ERROR(Status)) {
+      PciDevice->PciExpStruct.DeviceControl.Uint16 = PcieDev.Uint16;
+    } else {
+      DEBUG (( DEBUG_ERROR, "Unexpected DeviceControl register (0x%x) write error!",
+          Offset
+      ));
+    }
+  } else {
+    DEBUG (( DEBUG_INFO, "No write of RO,", PciDevice->SetupRO.Act));
+  }
+
+  return Status;
+}
+
 /**
   helper routine to dump the PCIe Device Port Type
 **/
@@ -1122,6 +1197,9 @@ ProgramDevicePciFeatures (
   if (SetupMaxReadReqSize ()) {
     Status = OverrideMaxReadReqSize (PciDevice);
   }
+  if (SetupRelaxOrder ()) {
+    Status = OverrideRelaxOrder (PciDevice);
+  }
   DEBUG (( DEBUG_INFO, "\n"));
   return Status;
 }
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.h b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.h
index 96ee6ff..5044dc2 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.h
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.h
@@ -40,6 +40,11 @@ typedef struct _OTHER_PCI_FEATURES_CONFIGURATION_TABLE  OTHER_PCI_FEATURES_CONFI
 //
 typedef struct _PCI_FEATURE_CONFIGURATION_COMPLETION_LIST  PCI_FEATURE_CONFIGURATION_COMPLETION_LIST;
 
+//
+// define the data type for the PCI feature policy support
+//
+typedef struct _PCI_FEATURE_POLICY  PCI_FEATURE_POLICY;
+
 //
 // Signature value for the PCI Root Port node
 //
@@ -151,6 +156,27 @@ typedef enum {
 
 }PCI_FEATURE_CONFIGURATION_PHASE;
 
+//
+// declaration for the data type to harbor the PCI feature policies
+//
+struct  _PCI_FEATURE_POLICY {
+  //
+  // if set, it indicates the feature should be enabled
+  // if clear, it indicates the feature should be disabled
+  //
+  UINT8   Act : 1;
+  //
+  // this field will be specific to feature, it can be implementation specific
+  // or it can be reserved and remain unused
+  //
+  UINT8   Support : 6;
+  //
+  // if set indicates override the feature policy defined by the members above
+  // if clear it indicates that this feature policy should be ignored completely
+  // this means the above two members should not be used
+  //
+  UINT8   Override : 1;
+};
 
 /**
   Main routine to indicate platform selection of any of the other PCI features
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
index f032b5d..f1e7039 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
@@ -470,6 +470,45 @@ TranslateMrrsSetupValueToPci (
   }
 }
 
+/**
+  Routine to set the device-specific policy for the PCI feature Relax Ordering
+
+  @param  RelaxOrder    value corresponding to data type EFI_PCI_CONF_RELAX_ORDER
+  @param  PciDevice     A pointer to PCI_IO_DEVICE
+**/
+VOID
+SetDevicePolicyRelaxOrder (
+  IN  EFI_PCI_CONF_RELAX_ORDER    RelaxOrder,
+  OUT PCI_IO_DEVICE               *PciDevice
+  )
+{
+  //
+  // implementation specific rules for the usage of PCI_FEATURE_POLICY members
+  // exclusively for the PCI Feature Relax Ordering (RO)
+  //
+  // .Override = 0 to skip this PCI feature RO for the PCI device
+  // .Override = 1 to program this RO PCI feature
+  //      .Act = 1 to enable the RO in the PCI device
+  //      .Act = 0 to disable the RO in the PCI device
+  //
+  switch (RelaxOrder) {
+    case  EFI_PCI_CONF_RO_AUTO:
+      PciDevice->SetupRO.Override = 0;
+      break;
+    case  EFI_PCI_CONF_RO_DISABLE:
+      PciDevice->SetupRO.Override = 1;
+      PciDevice->SetupRO.Act = 0;
+      break;
+    case  EFI_PCI_CONF_RO_ENABLE:
+      PciDevice->SetupRO.Override = 1;
+      PciDevice->SetupRO.Act = 1;
+      break;
+    default:
+      PciDevice->SetupRO.Override = 0;
+      break;
+  }
+}
+
 /**
   Generic routine to setup the PCI features as per its predetermined defaults.
 **/
@@ -480,6 +519,7 @@ SetupDefaultsDevicePlatformPolicy (
 {
   PciDevice->SetupMPS = EFI_PCI_CONF_MAX_PAYLOAD_SIZE_AUTO;
   PciDevice->SetupMRRS = EFI_PCI_CONF_MAX_READ_REQ_SIZE_AUTO;
+  PciDevice->SetupRO.Override = 0;
 }
 
 /**
@@ -517,6 +557,10 @@ GetPciDevicePlatformPolicyEx (
       //
       PciIoDevice->SetupMPS = PciPlatformExtendedPolicy.DeviceCtlMPS;
       PciIoDevice->SetupMRRS = PciPlatformExtendedPolicy.DeviceCtlMRRS;
+      //
+      // set device specific policy for Relax Ordering
+      //
+      SetDevicePolicyRelaxOrder (PciPlatformExtendedPolicy.DeviceCtlRelaxOrder, PciIoDevice);
 
       DEBUG ((
           DEBUG_INFO, "[device policy: platform]"
-- 
2.21.0.windows.1