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IntelSiliconPkg IntelVTdDxe: Check HeaderType if func 0 is implemented

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REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1169

Current code checks HeaderType of Function 0 even Function 0 is not
implemented. HeaderType value will be 0xFF if Function 0 is not
implemented, then MaxFunction will be set to PCI_MAX_FUNC + 1.

The code can be optimized to only check HeaderType if Function 0 is
implemented.

Test done:
With this patch, the result is same with the result after the patch at
https://lists.01.org/pipermail/edk2-devel/2018-September/029623.html.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Tomson Chang <tomson.chang@intel.com>
Cc: Jenny Huang <jenny.huang@intel.com>
Cc: Amy Chan <amy.chan@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
(cherry picked from commit b06dfd40bb)
This commit is contained in:
Star Zeng
2018-09-13 14:27:47 +08:00
parent 935c402311
commit c924df7ccf
1 changed files with 12 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
IntelSiliconPkg/Feature/VTd/IntelVTdDxe/PciInfo.c
View File

@@ -231,19 +231,13 @@ ScanPciBus (
UINT8 HeaderType;
UINT8 BaseClass;
UINT8 SubClass;
UINT32 MaxFunction;
UINT16 VendorID;
UINT16 DeviceID;
EFI_STATUS Status;
// Scan the PCI bus for devices
for (Device = 0; Device < PCI_MAX_DEVICE + 1; Device++) {
HeaderType = PciSegmentRead8 (PCI_SEGMENT_LIB_ADDRESS(Segment, Bus, Device, 0, PCI_HEADER_TYPE_OFFSET));
MaxFunction = PCI_MAX_FUNC + 1;
if ((HeaderType & HEADER_TYPE_MULTI_FUNCTION) == 0x00) {
MaxFunction = 1;
}
for (Function = 0; Function < MaxFunction; Function++) {
for (Device = 0; Device <= PCI_MAX_DEVICE; Device++) {
for (Function = 0; Function <= PCI_MAX_FUNC; Function++) {
VendorID = PciSegmentRead16 (PCI_SEGMENT_LIB_ADDRESS(Segment, Bus, Device, Function, PCI_VENDOR_ID_OFFSET));
DeviceID = PciSegmentRead16 (PCI_SEGMENT_LIB_ADDRESS(Segment, Bus, Device, Function, PCI_DEVICE_ID_OFFSET));
if (VendorID == 0xFFFF && DeviceID == 0xFFFF) {
@@ -275,6 +269,16 @@ ScanPciBus (
}
}
}
if (Function == 0) {
HeaderType = PciSegmentRead8 (PCI_SEGMENT_LIB_ADDRESS(Segment, Bus, Device, 0, PCI_HEADER_TYPE_OFFSET));
if ((HeaderType & HEADER_TYPE_MULTI_FUNCTION) == 0x00) {
//
// It is not a multi-function device, do not scan other functions.
//
break;
}
}
}
}