MdeModulePkg/PciBusDxe: Refine code to make it more readable

[mirror_edk2.git] / MdeModulePkg / Bus / Pci / PciBusDxe / PciHotPlugSupport.c

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciHotPlugSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciHotPlugSupport.c
index 61172be78e67dee991666e01a2bd40671ec7ac00..73bcd32788d1c2ffb5a7f540e2df7b0693df8602 100644 (file)
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciHotPlugSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciHotPlugSupport.c
@@ -1,7 +1,7 @@
 /** @file\r
   PCI Hot Plug support functions implementation for PCI Bus module..\r
 \r
-Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials\r
 are licensed and made available under the terms and conditions of the BSD License\r
 which accompanies this distribution.  The full text of the license may be found at\r
@@ -254,7 +254,7 @@ AllRootHPCInitialized (
   do {\r
     for (Index = 0; Index < gPciRootHpcCount; Index++) {\r
 \r
-      if (!gPciRootHpcData[Index].Initialized) {\r
+      if (gPciRootHpcData[Index].Found && !gPciRootHpcData[Index].Initialized) {\r
         break;\r
       }\r
     }\r
@@ -300,7 +300,7 @@ IsSHPC (
   Offset = 0;\r
   Status = LocateCapabilityRegBlock (\r
             PciIoDevice,\r
-            EFI_PCI_CAPABILITY_ID_HOTPLUG,\r
+            EFI_PCI_CAPABILITY_ID_SHPC,\r
             &Offset,\r
             NULL\r
             );\r
@@ -316,6 +316,94 @@ IsSHPC (
   return FALSE;\r
 }\r
 \r
+/**\r
+  Check whether PciIoDevice supports PCIe hotplug.\r
+\r
+  This is equivalent to the following condition:\r
+  - the device is either a PCIe switch downstream port or a root port,\r
+  - and the device has the SlotImplemented bit set in its PCIe capability\r
+    register,\r
+  - and the device has the HotPlugCapable bit set in its slot capabilities\r
+    register.\r
+\r
+  @param[in] PciIoDevice  The device being checked.\r
+\r
+  @retval TRUE   PciIoDevice is a PCIe port that accepts a hotplugged device.\r
+  @retval FALSE  Otherwise.\r
+\r
+**/\r
+BOOLEAN\r
+SupportsPcieHotplug (\r
+  IN PCI_IO_DEVICE                      *PciIoDevice\r
+  )\r
+{\r
+  UINT32                       Offset;\r
+  EFI_STATUS                   Status;\r
+  PCI_REG_PCIE_CAPABILITY      Capability;\r
+  PCI_REG_PCIE_SLOT_CAPABILITY SlotCapability;\r
+\r
+  if (PciIoDevice == NULL) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Read the PCI Express Capabilities Register\r
+  //\r
+  if (!PciIoDevice->IsPciExp) {\r
+    return FALSE;\r
+  }\r
+  Offset = PciIoDevice->PciExpressCapabilityOffset +\r
+           OFFSET_OF (PCI_CAPABILITY_PCIEXP, Capability);\r
+  Status = PciIoDevice->PciIo.Pci.Read (\r
+                                    &PciIoDevice->PciIo,\r
+                                    EfiPciIoWidthUint16,\r
+                                    Offset,\r
+                                    1,\r
+                                    &Capability\r
+                                    );\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Check the contents of the register\r
+  //\r
+  switch (Capability.Bits.DevicePortType) {\r
+  case PCIE_DEVICE_PORT_TYPE_ROOT_PORT:\r
+  case PCIE_DEVICE_PORT_TYPE_DOWNSTREAM_PORT:\r
+    break;\r
+  default:\r
+    return FALSE;\r
+  }\r
+  if (!Capability.Bits.SlotImplemented) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Read the Slot Capabilities Register\r
+  //\r
+  Offset = PciIoDevice->PciExpressCapabilityOffset +\r
+           OFFSET_OF (PCI_CAPABILITY_PCIEXP, SlotCapability);\r
+  Status = PciIoDevice->PciIo.Pci.Read (\r
+                                    &PciIoDevice->PciIo,\r
+                                    EfiPciIoWidthUint32,\r
+                                    Offset,\r
+                                    1,\r
+                                    &SlotCapability\r
+                                    );\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Check the contents of the register\r
+  //\r
+  if (SlotCapability.Bits.HotPlugCapable) {\r
+    return TRUE;\r
+  }\r
+  return FALSE;\r
+}\r
+\r
 /**\r
   Get resource padding if the specified PCI bridge is a hot plug bus.\r
 \r
@@ -382,6 +470,14 @@ IsPciHotPlugBus (
     return TRUE;\r
   }\r
 \r
+  if (SupportsPcieHotplug (PciIoDevice)) {\r
+    //\r
+    // If the PPB is a PCIe root complex port or a switch downstream port, and\r
+    // implements a hot-plug capable slot, then also return TRUE.\r
+    //\r
+    return TRUE;\r
+  }\r
+\r
   //\r
   // Otherwise, see if it is a Root HPC\r
   //\r