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 --- arch/mips/mm/sc-debugfs.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 arch/mips/mm/sc-debugfs.c (limited to 'arch/mips/mm/sc-debugfs.c') diff --git a/arch/mips/mm/sc-debugfs.c b/arch/mips/mm/sc-debugfs.c new file mode 100644 index 000000000..80ff39471 --- /dev/null +++ b/arch/mips/mm/sc-debugfs.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015 Imagination Technologies + * Author: Paul Burton + */ + +#include +#include +#include +#include +#include + +static ssize_t sc_prefetch_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + bool enabled = bc_prefetch_is_enabled(); + char buf[3]; + + buf[0] = enabled ? 'Y' : 'N'; + buf[1] = '\n'; + buf[2] = 0; + + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static ssize_t sc_prefetch_write(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + bool enabled; + int err; + + err = kstrtobool_from_user(user_buf, count, &enabled); + if (err) + return err; + + if (enabled) + bc_prefetch_enable(); + else + bc_prefetch_disable(); + + return count; +} + +static const struct file_operations sc_prefetch_fops = { + .open = simple_open, + .llseek = default_llseek, + .read = sc_prefetch_read, + .write = sc_prefetch_write, +}; + +static int __init sc_debugfs_init(void) +{ + struct dentry *dir; + + dir = debugfs_create_dir("l2cache", mips_debugfs_dir); + debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir, NULL, + &sc_prefetch_fops); + return 0; +} +late_initcall(sc_debugfs_init); -- cgit v1.3.1