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authorJoseph Shifflett <joseph.shifflett@hpe.com>2015-10-06 20:55:31 +0000
committerlersek <lersek@Edk2>2015-10-06 20:55:31 +0000
commit25a2664625f892e4a35cdb57a567e060bcde043c (patch)
tree45175d9ab9de186c594b4e2c4b82363dfd1f7b61
parentc5a693cea60823e0a3df5a3e92604e4e8936c84a (diff)
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MdeModulePkg: exit pci function loops early if device is not multi-function
When looping through all PCI functions, code should not look for functions 1-7 if function 0 is not present or if function 0 indicates the device is not multifunction. Prior to this fix the code would use stale data in a buffer to determine if a device is multifunction even if function 0 is not present. This fixes a code bug and provides very small performance improvements. PCI 2.3 Specification states: They [multifunction devices] are also required to always implement function 0 in the device. Implementing other functions is optional and may be assigned in any order. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Joseph Shifflett <joseph.shifflett@hpe.com> Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18574 6f19259b-4bc3-4df7-8a09-765794883524
-rw-r--r--MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c8
-rw-r--r--MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c16
-rw-r--r--MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c8
3 files changed, 32 insertions, 0 deletions
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c
index 7329143..597c083 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c
@@ -2,6 +2,7 @@
PCI eunmeration implementation on entire PCI bus system for PCI Bus module.
Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP<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
@@ -407,6 +408,13 @@ PciAssignBusNumber (
Func
);
+ if (EFI_ERROR (Status) && Func == 0) {
+ //
+ // go to next device if there is no Function 0
+ //
+ break;
+ }
+
if (!EFI_ERROR (Status) &&
(IS_PCI_BRIDGE (&Pci) || IS_CARDBUS_BRIDGE (&Pci))) {
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
index f46025e..f7aea4f 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -2,6 +2,7 @@
PCI emumeration support functions implementation for PCI Bus module.
Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP<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
@@ -119,6 +120,14 @@ PciPciDeviceInfoCollector (
(UINT8) Device,
(UINT8) Func
);
+
+ if (EFI_ERROR (Status) && Func == 0) {
+ //
+ // go to next device if there is no Function 0
+ //
+ break;
+ }
+
if (!EFI_ERROR (Status)) {
//
@@ -2597,6 +2606,13 @@ ResetAllPpbBusNumber (
Func
);
+ if (EFI_ERROR (Status) && Func == 0) {
+ //
+ // go to next device if there is no Function 0
+ //
+ break;
+ }
+
if (!EFI_ERROR (Status) && (IS_PCI_BRIDGE (&Pci))) {
Register = 0;
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
index b3d91a8..3e275e3 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
@@ -2,6 +2,7 @@
Internal library implementation for PCI Bus module.
Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP<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
@@ -1022,6 +1023,13 @@ PciScanBus (
Func
);
+ if (EFI_ERROR (Status) && Func == 0) {
+ //
+ // go to next device if there is no Function 0
+ //
+ break;
+ }
+
if (EFI_ERROR (Status)) {
continue;
}