MdeModulePkg/PciBusDxe: Enable Bus Master on P2P bridges on demand

The patch dynamically enables Bus Master on P2P bridges only
when requested by a device driver through PciIo.Attribute() to enable
the Bus Master.

Signed-off-by: Sean Brogan <sean.brogan@microsoft.com>
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
This commit is contained in:
Ruiyu Ni 2017-08-16 10:26:49 -07:00
parent 265e5c82f5
commit 5db417ed25
3 changed files with 32 additions and 10 deletions

View File

@ -1,7 +1,7 @@
/** @file
Supporting functions implementaion for PCI devices management.
Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2006 - 2017, 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
@ -711,7 +711,12 @@ StartPciDevicesOnBridge (
0,
&Supports
);
Supports &= (UINT64)EFI_PCI_DEVICE_ENABLE;
//
// By default every bridge's IO and MMIO spaces are enabled.
// Bridge's Bus Master will be enabled when any device behind it requests
// to enable Bus Master.
//
Supports &= (UINT64) (EFI_PCI_IO_ATTRIBUTE_IO | EFI_PCI_IO_ATTRIBUTE_MEMORY);
PciIoDevice->PciIo.Attributes (
&(PciIoDevice->PciIo),
EfiPciIoAttributeOperationEnable,
@ -763,7 +768,12 @@ StartPciDevicesOnBridge (
0,
&Supports
);
Supports &= (UINT64)EFI_PCI_DEVICE_ENABLE;
//
// By default every bridge's IO and MMIO spaces are enabled.
// Bridge's Bus Master will be enabled when any device behind it requests
// to enable Bus Master.
//
Supports &= (UINT64) (EFI_PCI_IO_ATTRIBUTE_IO | EFI_PCI_IO_ATTRIBUTE_MEMORY);
PciIoDevice->PciIo.Attributes (
&(PciIoDevice->PciIo),
EfiPciIoAttributeOperationEnable,

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@ -1218,11 +1218,12 @@ DetermineDeviceAttribute (
return Status;
}
//
// Assume the PCI Root Bridge supports DAC
// Assume the PCI Root Bridge supports DAC and Bus Master.
//
PciIoDevice->Supports |= (UINT64)(EFI_PCI_IO_ATTRIBUTE_EMBEDDED_DEVICE |
EFI_PCI_IO_ATTRIBUTE_EMBEDDED_ROM |
EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE);
EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE |
EFI_PCI_IO_ATTRIBUTE_BUS_MASTER);
} else {
@ -1233,9 +1234,16 @@ DetermineDeviceAttribute (
//
Command = EFI_PCI_COMMAND_IO_SPACE |
EFI_PCI_COMMAND_MEMORY_SPACE |
EFI_PCI_COMMAND_BUS_MASTER |
EFI_PCI_COMMAND_VGA_PALETTE_SNOOP;
//
// Per PCI-to-PCI Bridge Architecture all PCI-to-PCI bridges are Bus Master capable.
// So only test the Bus Master capability for PCI devices.
//
if (!IS_PCI_BRIDGE(&PciIoDevice->Pci)) {
Command |= EFI_PCI_COMMAND_BUS_MASTER;
}
BridgeControl = EFI_PCI_BRIDGE_CONTROL_ISA | EFI_PCI_BRIDGE_CONTROL_VGA | EFI_PCI_BRIDGE_CONTROL_VGA_16;
//
@ -1245,7 +1253,11 @@ DetermineDeviceAttribute (
//
// Set the supported attributes for specified PCI device
// Per PCI-to-PCI Bridge Architecture all PCI-to-PCI bridges are Bus Master capable.
//
if (IS_PCI_BRIDGE(&PciIoDevice->Pci)) {
Command |= EFI_PCI_COMMAND_BUS_MASTER;
}
PciSetDeviceAttribute (PciIoDevice, Command, BridgeControl, EFI_SET_SUPPORTS);
//

View File

@ -1348,7 +1348,8 @@ ModifyRootBridgeAttributes (
//
Attributes &= ~(UINT64)(EFI_PCI_IO_ATTRIBUTE_EMBEDDED_DEVICE |
EFI_PCI_IO_ATTRIBUTE_EMBEDDED_ROM |
EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE);
EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE |
EFI_PCI_IO_ATTRIBUTE_BUS_MASTER);
//
// Record the new attribute of the Root Bridge
@ -1726,12 +1727,11 @@ PciIoAttributes (
}
//
// The upstream bridge should be also set to revelant attribute
// expect for IO, Mem and BusMaster
// expect for IO and Mem
//
UpStreamAttributes = Attributes &
(~(EFI_PCI_IO_ATTRIBUTE_IO |
EFI_PCI_IO_ATTRIBUTE_MEMORY |
EFI_PCI_IO_ATTRIBUTE_BUS_MASTER
EFI_PCI_IO_ATTRIBUTE_MEMORY
)
);
UpStreamBridge = PciIoDevice->Parent;