linux-kernel - [RFC v3 6/7] arm64: PCI: Support root bridge preparation for Hyper-V PCI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 10 Jun 2021 00:32:10 +0800
From:   Boqun Feng <boqun.feng@...il.com>
To:     Bjorn Helgaas <bhelgaas@...gle.com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-hyperv@...r.kernel.org, linux-pci@...r.kernel.org
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        Wei Liu <wei.liu@...nel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Rob Herring <robh@...nel.org>, Clint Sbisa <csbisa@...zon.com>,
        Boqun Feng <boqun.feng@...il.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        Sunil Muthuswamy <sunilmut@...rosoft.com>
Subject: [RFC v3 6/7] arm64: PCI: Support root bridge preparation for Hyper-V PCI

Currently at root bridge preparation, the corresponding ACPI device will
be set as the companion, however for a Hyper-V virtual PCI root bridge,
there is no corresponding ACPI device, because a Hyper-V virtual PCI
root bridge is discovered via VMBus rather than ACPI table. In order to
support this, we need to make pcibios_root_bridge_prepare() work with
cfg->parent being NULL.

Signed-off-by: Boqun Feng <boqun.feng@...il.com>
---
 arch/arm64/kernel/pci.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 1006ed2d7c60..020bc268bf06 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -84,7 +84,12 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 {
 	if (!acpi_disabled) {
 		struct pci_config_window *cfg = bridge->bus->sysdata;
-		struct acpi_device *adev = to_acpi_device(cfg->parent);
+		/*
+		 * On Hyper-V, there is no corresponding APCI device for a root
+		 * bridge, therefore ->parent is set as NULL by the driver. Then
+		 * 'adev' should be NULL in this case.
+		 */
+		struct acpi_device *adev = cfg->parent ? to_acpi_device(cfg->parent) : NULL;
 		struct device *bus_dev = &bridge->bus->dev;
 
 		ACPI_COMPANION_SET(&bridge->dev, adev);
-- 
2.30.2