[PATCH 7/8] PCI: hv: Allocate a named fwnode instead of an address-based one

From: Marc Zyngier <maz@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linusw@kernel.org>, Imre Kaloz <kaloz@openwrt.org>,
	Krzysztof Halasa <khalasa@piap.pl>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 7/8] PCI: hv: Allocate a named fwnode instead of an address-based one
Date: Tue,  6 Aug 2019 15:57:15 +0100	[thread overview]
Message-ID: <20190806145716.125421-8-maz@kernel.org> (raw)
In-Reply-To: <20190806145716.125421-1-maz@kernel.org>

To allocate its fwnode that is then used to allocate an irqdomain,
the driver uses irq_domain_alloc_fwnode(), passing it a VA as an
identifier. This is a rather bad idea, as this address ends up
published in debugfs (and we want to move away from VAs there
anyway).

Instead, let's allocate a named fwnode by using the device GUID as
an identifier. It is allegedly unique, and can be traced back to
the original device.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/pci/controller/pci-hyperv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 40b625458afa..f6ed2583167a 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -2521,6 +2521,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 			const struct hv_vmbus_device_id *dev_id)
 {
 	struct hv_pcibus_device *hbus;
+	char *name;
 	int ret;
 
 	/*
@@ -2589,7 +2590,14 @@ static int hv_pci_probe(struct hv_device *hdev,
 		goto free_config;
 	}
 
-	hbus->sysdata.fwnode = irq_domain_alloc_fwnode(hbus);
+	name = kasprintf("%pUL", &hdev->dev_instance);
+	if (!name) {
+		ret = -ENOMEM;
+		goto unmap;
+	}
+
+	hbus->sysdata.fwnode = irq_domain_alloc_named_fwnode(name);
+	kfree(name);
 	if (!hbus->sysdata.fwnode) {
 		ret = -ENOMEM;
 		goto unmap;
-- 
2.20.1

