x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/input/misc/pf1550-onkey.c b/drivers/input/misc/pf1550-onkey.c
new file mode 100644
index 000000000..0d1b570bb
--- /dev/null
+++ b/drivers/input/misc/pf1550-onkey.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the PF1550 ONKEY
+ * Copyright (C) 2016 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * Portions Copyright (c) 2025 Savoir-faire Linux Inc.
+ * Samuel Kayode <samuel.kayode@savoirfairelinux.com>
+ */
+
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/pf1550.h>
+#include <linux/platform_device.h>
+
+#define PF1550_ONKEY_IRQ_NR	6
+
+struct onkey_drv_data {
+	struct device *dev;
+	const struct pf1550_ddata *pf1550;
+	bool wakeup;
+	struct input_dev *input;
+};
+
+static irqreturn_t pf1550_onkey_irq_handler(int irq, void *data)
+{
+	struct onkey_drv_data *onkey = data;
+	struct platform_device *pdev = to_platform_device(onkey->dev);
+	int i, state, irq_type = -1;
+
+	for (i = 0; i < PF1550_ONKEY_IRQ_NR; i++)
+		if (irq == platform_get_irq(pdev, i))
+			irq_type = i;
+
+	switch (irq_type) {
+	case PF1550_ONKEY_IRQ_PUSHI:
+		state = 0;
+		break;
+	case PF1550_ONKEY_IRQ_1SI:
+	case PF1550_ONKEY_IRQ_2SI:
+	case PF1550_ONKEY_IRQ_3SI:
+	case PF1550_ONKEY_IRQ_4SI:
+	case PF1550_ONKEY_IRQ_8SI:
+		state = 1;
+		break;
+	default:
+		dev_err(onkey->dev, "onkey interrupt: irq %d occurred\n",
+			irq_type);
+		return IRQ_HANDLED;
+	}
+
+	input_event(onkey->input, EV_KEY, KEY_POWER, state);
+	input_sync(onkey->input);
+
+	return IRQ_HANDLED;
+}
+
+static int pf1550_onkey_probe(struct platform_device *pdev)
+{
+	struct onkey_drv_data *onkey;
+	struct input_dev *input;
+	bool key_power = false;
+	int i, irq, error;
+
+	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
+	if (!onkey)
+		return -ENOMEM;
+
+	onkey->dev = &pdev->dev;
+
+	onkey->pf1550 = dev_get_drvdata(pdev->dev.parent);
+	if (!onkey->pf1550->regmap)
+		return dev_err_probe(&pdev->dev, -ENODEV,
+				     "failed to get regmap\n");
+
+	onkey->wakeup = device_property_read_bool(pdev->dev.parent,
+						  "wakeup-source");
+
+	if (device_property_read_bool(pdev->dev.parent,
+				      "nxp,disable-key-power")) {
+		error = regmap_clear_bits(onkey->pf1550->regmap,
+					  PF1550_PMIC_REG_PWRCTRL1,
+					  PF1550_ONKEY_RST_EN);
+		if (error)
+			return dev_err_probe(&pdev->dev, error,
+					     "failed: disable turn system off");
+	} else {
+		key_power = true;
+	}
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input)
+		return dev_err_probe(&pdev->dev, -ENOMEM,
+				     "failed to allocate the input device\n");
+
+	input->name = pdev->name;
+	input->phys = "pf1550-onkey/input0";
+	input->id.bustype = BUS_HOST;
+
+	if (key_power)
+		input_set_capability(input, EV_KEY, KEY_POWER);
+
+	onkey->input = input;
+	platform_set_drvdata(pdev, onkey);
+
+	for (i = 0; i < PF1550_ONKEY_IRQ_NR; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			return irq;
+
+		error = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+						  pf1550_onkey_irq_handler,
+						  IRQF_NO_SUSPEND,
+						  "pf1550-onkey", onkey);
+		if (error)
+			return dev_err_probe(&pdev->dev, error,
+					     "failed: irq request (IRQ: %d)\n",
+					     i);
+	}
+
+	error = input_register_device(input);
+	if (error)
+		return dev_err_probe(&pdev->dev, error,
+				     "failed to register input device\n");
+
+	device_init_wakeup(&pdev->dev, onkey->wakeup);
+
+	return 0;
+}
+
+static int pf1550_onkey_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct onkey_drv_data *onkey = platform_get_drvdata(pdev);
+	int i, irq;
+
+	if (!device_may_wakeup(&pdev->dev))
+		regmap_write(onkey->pf1550->regmap,
+			     PF1550_PMIC_REG_ONKEY_INT_MASK0,
+			     ONKEY_IRQ_PUSHI | ONKEY_IRQ_1SI | ONKEY_IRQ_2SI |
+			     ONKEY_IRQ_3SI | ONKEY_IRQ_4SI | ONKEY_IRQ_8SI);
+	else
+		for (i = 0; i < PF1550_ONKEY_IRQ_NR; i++) {
+			irq = platform_get_irq(pdev, i);
+			if (irq > 0)
+				enable_irq_wake(irq);
+		}
+
+	return 0;
+}
+
+static int pf1550_onkey_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct onkey_drv_data *onkey = platform_get_drvdata(pdev);
+	int i, irq;
+
+	if (!device_may_wakeup(&pdev->dev))
+		regmap_write(onkey->pf1550->regmap,
+			     PF1550_PMIC_REG_ONKEY_INT_MASK0,
+			     ~((u8)(ONKEY_IRQ_PUSHI | ONKEY_IRQ_1SI |
+			     ONKEY_IRQ_2SI | ONKEY_IRQ_3SI | ONKEY_IRQ_4SI |
+			     ONKEY_IRQ_8SI)));
+	else
+		for (i = 0; i < PF1550_ONKEY_IRQ_NR; i++) {
+			irq = platform_get_irq(pdev, i);
+			if (irq > 0)
+				disable_irq_wake(irq);
+		}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pf1550_onkey_pm_ops, pf1550_onkey_suspend,
+			 pf1550_onkey_resume);
+
+static const struct platform_device_id pf1550_onkey_id[] = {
+	{ "pf1550-onkey", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, pf1550_onkey_id);
+
+static struct platform_driver pf1550_onkey_driver = {
+	.driver = {
+		.name = "pf1550-onkey",
+		.pm   = pm_sleep_ptr(&pf1550_onkey_pm_ops),
+	},
+	.probe = pf1550_onkey_probe,
+	.id_table = pf1550_onkey_id,
+};
+module_platform_driver(pf1550_onkey_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor");
+MODULE_DESCRIPTION("PF1550 onkey Driver");
+MODULE_LICENSE("GPL");