linux-kernel - [PATCH v9 2/5] PCI/pwrctl: Reuse the OF node for power controlled devices

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]

Message-ID: <20240612082019.19161-3-brgl@bgdev.pl>
Date: Wed, 12 Jun 2024 10:20:15 +0200
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Bjorn Helgaas <bhelgaas@...gle.com>
Cc: linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
	Amit Pundir <amit.pundir@...aro.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Caleb Connolly <caleb.connolly@...aro.org>
Subject: [PATCH v9 2/5] PCI/pwrctl: Reuse the OF node for power controlled devices

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

With PCI power control we deal with two struct device objects bound to
two different drivers but consuming the same OF node. We must not bind
the pinctrl twice. To that end: before setting the OF node of the newly
instantiated PCI device, check if a platform device consuming the same
OF node doesn't already exist on the platform bus and - if so - mark the
PCI device as reusing the OF node.

Tested-by: Amit Pundir <amit.pundir@...aro.org>
Tested-by: Neil Armstrong <neil.armstrong@...aro.org> # on SM8550-QRD, SM8650-QRD & SM8650-HDK
Tested-by: Caleb Connolly <caleb.connolly@...aro.org> # OnePlus 8T
Acked-by: Bjorn Helgaas <bhelgaas@...gle.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/pci/of.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 48ba95e4ab05..dacea3fc5128 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -6,6 +6,7 @@
  */
 #define pr_fmt(fmt)	"PCI: OF: " fmt
 
+#include <linux/cleanup.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
@@ -13,6 +14,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
+#include <linux/platform_device.h>
 #include "pci.h"
 
 #ifdef CONFIG_PCI
@@ -25,16 +27,20 @@
  */
 int pci_set_of_node(struct pci_dev *dev)
 {
-	struct device_node *node;
-
 	if (!dev->bus->dev.of_node)
 		return 0;
 
-	node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
+	struct device_node *node __free(device_node) =
+		of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
 	if (!node)
 		return 0;
 
-	device_set_node(&dev->dev, of_fwnode_handle(node));
+	struct device *pdev __free(put_device) =
+		bus_find_device_by_of_node(&platform_bus_type, node);
+	if (pdev)
+		dev->bus->dev.of_node_reused = true;
+
+	device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
 	return 0;
 }
 
-- 
2.40.1