From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() 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 Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/reset/reset-ath79.c | 127 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 drivers/reset/reset-ath79.c (limited to 'drivers/reset/reset-ath79.c') diff --git a/drivers/reset/reset-ath79.c b/drivers/reset/reset-ath79.c new file mode 100644 index 000000000..1a2c0f8a5 --- /dev/null +++ b/drivers/reset/reset-ath79.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * AR71xx Reset Controller Driver + * Author: Alban Bedel + * + * Copyright (C) 2015 Alban Bedel + */ + +#include +#include +#include +#include +#include + +struct ath79_reset { + struct reset_controller_dev rcdev; + void __iomem *base; + spinlock_t lock; +}; + +#define FULL_CHIP_RESET 24 + +static int ath79_reset_update(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct ath79_reset *ath79_reset = + container_of(rcdev, struct ath79_reset, rcdev); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&ath79_reset->lock, flags); + val = readl(ath79_reset->base); + if (assert) + val |= BIT(id); + else + val &= ~BIT(id); + writel(val, ath79_reset->base); + spin_unlock_irqrestore(&ath79_reset->lock, flags); + + return 0; +} + +static int ath79_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ath79_reset_update(rcdev, id, true); +} + +static int ath79_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ath79_reset_update(rcdev, id, false); +} + +static int ath79_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ath79_reset *ath79_reset = + container_of(rcdev, struct ath79_reset, rcdev); + u32 val; + + val = readl(ath79_reset->base); + + return !!(val & BIT(id)); +} + +static const struct reset_control_ops ath79_reset_ops = { + .assert = ath79_reset_assert, + .deassert = ath79_reset_deassert, + .status = ath79_reset_status, +}; + +static int ath79_reset_restart_handler(struct sys_off_data *data) +{ + struct ath79_reset *ath79_reset = data->cb_data; + + ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET); + + return NOTIFY_DONE; +} + +static int ath79_reset_probe(struct platform_device *pdev) +{ + struct ath79_reset *ath79_reset; + int err; + + ath79_reset = devm_kzalloc(&pdev->dev, + sizeof(*ath79_reset), GFP_KERNEL); + if (!ath79_reset) + return -ENOMEM; + + ath79_reset->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ath79_reset->base)) + return PTR_ERR(ath79_reset->base); + + spin_lock_init(&ath79_reset->lock); + ath79_reset->rcdev.ops = &ath79_reset_ops; + ath79_reset->rcdev.owner = THIS_MODULE; + ath79_reset->rcdev.of_node = pdev->dev.of_node; + ath79_reset->rcdev.of_reset_n_cells = 1; + ath79_reset->rcdev.nr_resets = 32; + + err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev); + if (err) + return err; + + err = devm_register_restart_handler(&pdev->dev, ath79_reset_restart_handler, ath79_reset); + if (err) + dev_warn(&pdev->dev, "Failed to register restart handler\n"); + + return 0; +} + +static const struct of_device_id ath79_reset_dt_ids[] = { + { .compatible = "qca,ar7100-reset", }, + { }, +}; + +static struct platform_driver ath79_reset_driver = { + .probe = ath79_reset_probe, + .driver = { + .name = "ath79-reset", + .of_match_table = ath79_reset_dt_ids, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(ath79_reset_driver); -- cgit v1.3.1