From 5db417ed2522367290c365831f9d6628d31c346c Mon Sep 17 00:00:00 2001 From: Ruiyu Ni Date: Wed, 16 Aug 2017 10:26:49 -0700 Subject: [PATCH] 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 Signed-off-by: Ruiyu Ni Reviewed-by: Jiewen Yao Cc: Michael D Kinney --- .../Bus/Pci/PciBusDxe/PciDeviceSupport.c | 16 +++++++++++++--- .../Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 18 +++++++++++++++--- MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c | 8 ++++---- 3 files changed, 32 insertions(+), 10 deletions(-) diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c index c0227fa2b6..359b9ded6d 100644 --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c @@ -1,7 +1,7 @@ /** @file Supporting functions implementaion for PCI devices management. -Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
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, diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c index 81171c82d9..f73756a31e 100644 --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c @@ -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); // diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c index cc7125e4fc..659f480d71 100644 --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c @@ -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; -- 2.39.2