Reviewed-by: Eric Dong <eric.d...@intel.com>
-----Original Message-----
From: Ni, Ruiyu
Sent: Thursday, July 30, 2015 11:11 AM
To: edk2-devel@lists.01.org
Cc: Ni, Ruiyu; Dong, Eric
Subject: [Patch] MdeModulePkg: Enhance PciBusDxe to handle high 32bit of MEM64
BAR returns 0
According to the PCI spec, when software writes all-one to BAR for size
probing, the value read back should be 0b1...10...0 after masking the BAR type
bits.
But in real world, it's possible that certain device returns 0b0...01...10...0
for MEM64 BAR size probing: some bits in the high 32bit may be 0.
PciBus driver has the code to handle such case. However, it doesn't handle the
case that the high 32bit is totally 0. The patch is to handle the special case.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ruiyu Ni <ruiyu...@intel.com>
Cc: Eric Dong <eric.d...@intel.com>
---
MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
index 9e7ac74..f46025e 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -1,7 +1,7 @@
/** @file
PCI emumeration support functions implementation for PCI Bus module.
-Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available
under the terms and conditions of the BSD License which accompanies this
distribution. The full text of the license may be found at @@ -1770,14
+1770,19 @@ PciParseBar (
// some device implement MMIO bar with 0 length, need to treat it as
no-bar
//
PciIoDevice->PciBar[BarIndex].BarType = PciBarTypeUnknown;
+ return Offset + 4;
}
- return Offset + 4;
}
//
// Fix the length to support some spefic 64 bit BAR
//
- Value |= ((UINT32)(-1) << HighBitSet32 (Value));
+ if (Value == 0) {
+ DEBUG ((EFI_D_INFO, "[PciBus]BAR probing for upper 32bit of MEM64 BAR
returns 0, change to 0xFFFFFFFF.\n"));
+ Value = (UINT32) -1;
+ } else {
+ Value |= ((UINT32)(-1) << HighBitSet32 (Value));
+ }
//
// Calculate the size of 64bit bar
--
1.9.5.msysgit.1
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