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, 165 insertions, 0 deletions

diff --git a/arch/arm/mach-omap1/timer.c b/arch/arm/mach-omap1/timer.c
new file mode 100644
index 000000000..399e6d840
--- /dev/null
+++ b/arch/arm/mach-omap1/timer.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMAP1 Dual-Mode Timers - platform device registration
+ *
+ * Contains first level initialization routines which internally
+ * generates timer device information and registers with linux
+ * device model. It also has a low level function to change the timer
+ * input clock source.
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
+ * Tarun Kanti DebBarma <tarun.kanti@ti.com>
+ * Thara Gopinath <thara@ti.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/dmtimer-omap.h>
+#include <linux/soc/ti/omap1-io.h>
+
+#include <clocksource/timer-ti-dm.h>
+
+#include "soc.h"
+
+#define OMAP1610_GPTIMER1_BASE		0xfffb1400
+#define OMAP1610_GPTIMER2_BASE		0xfffb1c00
+#define OMAP1610_GPTIMER3_BASE		0xfffb2400
+#define OMAP1610_GPTIMER4_BASE		0xfffb2c00
+#define OMAP1610_GPTIMER5_BASE		0xfffb3400
+#define OMAP1610_GPTIMER6_BASE		0xfffb3c00
+#define OMAP1610_GPTIMER7_BASE		0xfffb7400
+#define OMAP1610_GPTIMER8_BASE		0xfffbd400
+
+#define OMAP1_DM_TIMER_COUNT		8
+
+static int omap1_dm_timer_set_src(struct platform_device *pdev,
+				int source)
+{
+	int n = (pdev->id - 1) << 1;
+	u32 l;
+
+	l = omap_readl(MOD_CONF_CTRL_1) & ~(0x03 << n);
+	l |= source << n;
+	omap_writel(l, MOD_CONF_CTRL_1);
+
+	return 0;
+}
+
+static int __init omap1_dm_timer_init(void)
+{
+	int i;
+	int ret;
+	struct dmtimer_platform_data *pdata;
+	struct platform_device *pdev;
+
+	if (!cpu_is_omap16xx())
+		return 0;
+
+	for (i = 1; i <= OMAP1_DM_TIMER_COUNT; i++) {
+		struct resource res[2];
+		u32 base, irq;
+
+		switch (i) {
+		case 1:
+			base = OMAP1610_GPTIMER1_BASE;
+			irq = INT_1610_GPTIMER1;
+			break;
+		case 2:
+			base = OMAP1610_GPTIMER2_BASE;
+			irq = INT_1610_GPTIMER2;
+			break;
+		case 3:
+			base = OMAP1610_GPTIMER3_BASE;
+			irq = INT_1610_GPTIMER3;
+			break;
+		case 4:
+			base = OMAP1610_GPTIMER4_BASE;
+			irq = INT_1610_GPTIMER4;
+			break;
+		case 5:
+			base = OMAP1610_GPTIMER5_BASE;
+			irq = INT_1610_GPTIMER5;
+			break;
+		case 6:
+			base = OMAP1610_GPTIMER6_BASE;
+			irq = INT_1610_GPTIMER6;
+			break;
+		case 7:
+			base = OMAP1610_GPTIMER7_BASE;
+			irq = INT_1610_GPTIMER7;
+			break;
+		case 8:
+			base = OMAP1610_GPTIMER8_BASE;
+			irq = INT_1610_GPTIMER8;
+			break;
+		default:
+			/*
+			 * not supposed to reach here.
+			 * this is to remove warning.
+			 */
+			return -EINVAL;
+		}
+
+		pdev = platform_device_alloc("omap_timer", i);
+		if (!pdev) {
+			pr_err("%s: Failed to device alloc for dmtimer%d\n",
+				__func__, i);
+			return -ENOMEM;
+		}
+
+		memset(res, 0, 2 * sizeof(struct resource));
+		res[0].start = base;
+		res[0].end = base + 0x46;
+		res[0].flags = IORESOURCE_MEM;
+		res[1].start = irq;
+		res[1].end = irq;
+		res[1].flags = IORESOURCE_IRQ;
+		ret = platform_device_add_resources(pdev, res,
+				ARRAY_SIZE(res));
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add resources.\n",
+				__func__);
+			goto err_free_pdev;
+		}
+
+		pdata = kzalloc_obj(*pdata);
+		if (!pdata) {
+			ret = -ENOMEM;
+			goto err_free_pdata;
+		}
+
+		pdata->set_timer_src = omap1_dm_timer_set_src;
+		pdata->timer_capability = OMAP_TIMER_ALWON |
+				OMAP_TIMER_NEEDS_RESET | OMAP_TIMER_HAS_DSP_IRQ;
+
+		ret = platform_device_add_data(pdev, pdata, sizeof(*pdata));
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add platform data.\n",
+				__func__);
+			goto err_free_pdata;
+		}
+
+		ret = platform_device_add(pdev);
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add platform device.\n",
+				__func__);
+			goto err_free_pdata;
+		}
+
+		dev_dbg(&pdev->dev, " Registered.\n");
+	}
+
+	return 0;
+
+err_free_pdata:
+	kfree(pdata);
+
+err_free_pdev:
+	platform_device_put(pdev);
+
+	return ret;
+}
+arch_initcall(omap1_dm_timer_init);