Files
system76-edk2/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
Laszlo Ersek 46e46eaf62 OvmfPkg: PciHostBridgeLib: convert main loop from PciHostBridgeDxe
In this patch we import the scan for extra root buses from the
InitializePciHostBridge() function, in file
"OvmfPkg/PciHostBridgeDxe/PciHostBridge.c".

For the time being, the InitRootBridge() and UninitRootBridge() functions
are just placeholders.

The PciHostBridgeGetRootBridges() API expects us to return the
PCI_ROOT_BRIDGE structures in a contiguous array, instead of a linked
list. Therefore the following bits have to be converted manually:

(1) The array is allocated in advance, in a single step.

(2) The calculation of the array size depends on an explicit
    multiplication, which we must check against overflow. Since more than
    255 extra root bridges make no sense anyway, we use (1 + 255) as the
    limit on the main plus all extra root bridges. This also ensures that
    the UINTN multiplication doesn't overflow.

(3) The PciHostBridgeDxe code decrements "ExtraRootBridgesLeft" to
    terminate the scanning early. Here we need track the increasing count
    of used array elements as well, so we employ "ExtraRootBridges" as a
    constant limit, and increment the new local variable "Initialized".

(4) The prototypes of InitRootBridge() and UninitRootBridge() reflect that
    the PCI_ROOT_BRIDGE structure is allocated by the caller; only
    in-place initialization is necessary.

Additionally, macros are employed for standard PCI quantities, from
"MdePkg/Include/IndustryStandard/Pci22.h":

- MAX_PCI_DEVICE_NUMBER (31) is replaced with PCI_MAX_DEVICE (same),
- the constant 255 is replaced with PCI_MAX_BUS,
- the (RootBridgeNumber < 256) condition is replaced with
  (RootBridgeNumber <= PCI_MAX_BUS).

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
2016-03-03 18:18:35 +01:00

46 lines
1.3 KiB
INI

## @file
# OVMF's instance of the PCI Host Bridge Library.
#
# Copyright (C) 2016, Red Hat, Inc.
# Copyright (c) 2016, 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
# http://opensource.org/licenses/bsd-license.php
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
# IMPLIED.
#
#
##
[Defines]
INF_VERSION = 0x00010005
BASE_NAME = PciHostBridgeLib
FILE_GUID = 9F2BC05E-51EA-4AED-9A3E-7699641734E8
MODULE_TYPE = DXE_DRIVER
VERSION_STRING = 1.0
LIBRARY_CLASS = PciHostBridgeLib
#
# The following information is for reference only and not required by the build
# tools.
#
# VALID_ARCHITECTURES = IA32 X64 IPF EBC
#
[Sources]
PciHostBridgeLib.c
[Packages]
MdeModulePkg/MdeModulePkg.dec
MdePkg/MdePkg.dec
OvmfPkg/OvmfPkg.dec
[LibraryClasses]
DebugLib
MemoryAllocationLib
PciLib
QemuFwCfgLib