[edk2-devel] [PATCH v2 2/2] MdeModulePkg:New Pcd to platform constrain BarSize

[Foster Nong <foster.nong@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4868
1. Define a new dynamic PCD in MdeModulePkg
   gEfiMdeModulePkgTokenSpaceGuid.PcdPcieResizableMaxBarSize
2. Modify PciProgramResizableBar() to implement configure BAR Size
   within platform constrain provided in PcdPcieResizableMaxBarSize

Signed-off-by: Foster Nong <foster.nong@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Ray Ni <ray.ni@intel.com>
---
 MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf |  1 +
 MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c      | 25 +++++++++++++++++---
 MdeModulePkg/MdeModulePkg.dec                |  5 ++++
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
index e317169d9c..f038b6eef2 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
@@ -107,6 +107,7 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdMrIovSupport                ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdPciDisableBusEnumeration    ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdPcieResizableBarSupport     ## CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPcieResizableMaxBarSize     ## CONSUMES
 
 [UserExtensions.TianoCore."ExtraFiles"]
   PciBusDxeExtra.uni
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
index dc5fd27665..95f331d0af 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
@@ -1797,6 +1797,7 @@ PciProgramResizableBar (
 {
   EFI_PCI_IO_PROTOCOL                                    *PciIo;
   UINT64                                                 Capabilities;
+  UINT64                                                 CapabilitiesMask;
   UINT32                                                 Index;
   UINT32                                                 Offset;
   INTN                                                   Bit;
@@ -1804,12 +1805,17 @@ PciProgramResizableBar (
   PCI_EXPRESS_EXTENDED_CAPABILITIES_RESIZABLE_BAR_ENTRY  Entries[PCI_MAX_BAR];
 
   ASSERT (PciIoDevice->ResizableBarOffset != 0);
-
+  //
+  // PCIE SPEC v6.0 section 7.8.6.3 Resizable BAR Control Register
+  // Bits[13:8] BAR Size define 43(8 EB) as maximum
+  //
+  CapabilitiesMask = LShiftU64 (1, MIN (PcdGet8 (PcdPcieResizableMaxBarSize), 43) + 1) - 1;
   DEBUG ((
     DEBUG_INFO,
-    "   Programs Resizable BAR register, offset: 0x%08x, number: %d\n",
+    "   Programs Resizable BAR register, offset: 0x%08x, number: %d, PcdPcieResizableMaxBarSize: %d\n",
     PciIoDevice->ResizableBarOffset,
-    PciIoDevice->ResizableBarNumber
+    PciIoDevice->ResizableBarNumber,
+    PcdGet8 (PcdPcieResizableMaxBarSize)
     ));
 
   if ((PciIoDevice->ResizableBarNumber > PCI_MAX_BAR) || (PciIoDevice->ResizableBarNumber == 0)) {
@@ -1853,9 +1859,22 @@ PciProgramResizableBar (
     // Bit 0 is set: supports operating with the BAR sized to 1 MB
     // Bit 1 is set: supports operating with the BAR sized to 2 MB
     // Bit n is set: supports operating with the BAR sized to (2^n) MB
+    // Platform may impose limitation on the BAR size it supports using PcdPcieResizableMaxBarSize.
     //
     Capabilities = LShiftU64 (Entries[Index].ResizableBarControl.Bits.BarSizeCapability, 28)
                    | Entries[Index].ResizableBarCapability.Bits.BarSizeCapability;
+    Capabilities &= CapabilitiesMask;
+
+    if (Capabilities == 0) {
+      DEBUG ((
+        DEBUG_ERROR,
+        " WARNING: Resizable BAR Entry[%d] skip, Capabilities=0x%llx CapabilitiesMask=0x%llx\n",
+        Index,
+        Entries[Index].ResizableBarCapability.Bits.BarSizeCapability,
+        CapabilitiesMask
+        ));
+      continue;
+    }
 
     if (ResizableBarOp == PciResizableBarMax) {
       Bit = HighBitSet64 (Capabilities);
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 1324b6d100..59fa506bd8 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -2264,6 +2264,11 @@
   # @Prompt The value is use for Usb Network rate limiting supported.
   gEfiMdeModulePkgTokenSpaceGuid.PcdUsbNetworkRateLimitingFactor|100|UINT32|0x10000028
 
+  # This PCD set maximum size of all PCIE Resizable BARs
+  # The max size equals to (2^PcdPcieResizableMaxBarSize) MB
+  # @Prompt Maximum size of PCIE Resizable BARs
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPcieResizableMaxBarSize|0x2B|UINT8|0x00030009
+
 [PcdsPatchableInModule]
   ## Specify memory size with page number for PEI code when
   #  Loading Module at Fixed Address feature is enabled.
-- 
2.37.1.windows.1



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