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/md/dm-path-selector.h | 107 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 drivers/md/dm-path-selector.h (limited to 'drivers/md/dm-path-selector.h') diff --git a/drivers/md/dm-path-selector.h b/drivers/md/dm-path-selector.h new file mode 100644 index 000000000..7b2270532 --- /dev/null +++ b/drivers/md/dm-path-selector.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2003 Sistina Software. + * Copyright (C) 2004 Red Hat, Inc. All rights reserved. + * + * Module Author: Heinz Mauelshagen + * + * This file is released under the GPL. + * + * Path-Selector registration. + */ + +#ifndef DM_PATH_SELECTOR_H +#define DM_PATH_SELECTOR_H + +#include + +#include "dm-mpath.h" + +/* + * We provide an abstraction for the code that chooses which path + * to send some io down. + */ +struct path_selector_type; +struct path_selector { + struct path_selector_type *type; + void *context; +}; + +/* + * If a path selector uses this flag, a high resolution timer is used + * (via ktime_get_ns) to account for IO start time in BIO-based mpath. + * This improves performance of some path selectors (i.e. HST), in + * exchange for slightly higher overhead when submitting the BIO. + * The extra cost is usually offset by improved path selection for + * some benchmarks. + * + * This has no effect for request-based mpath, since it already uses a + * higher precision timer by default. + */ +#define DM_PS_USE_HR_TIMER 0x00000001 +#define dm_ps_use_hr_timer(type) ((type)->features & DM_PS_USE_HR_TIMER) + +/* Information about a path selector type */ +struct path_selector_type { + char *name; + struct module *module; + + unsigned int features; + unsigned int table_args; + unsigned int info_args; + + /* + * Constructs a path selector object, takes custom arguments + */ + int (*create)(struct path_selector *ps, unsigned int argc, char **argv); + void (*destroy)(struct path_selector *ps); + + /* + * Add an opaque path object, along with some selector specific + * path args (eg, path priority). + */ + int (*add_path)(struct path_selector *ps, struct dm_path *path, + int argc, char **argv, char **error); + + /* + * Chooses a path for this io, if no paths are available then + * NULL will be returned. + */ + struct dm_path *(*select_path)(struct path_selector *ps, size_t nr_bytes); + + /* + * Notify the selector that a path has failed. + */ + void (*fail_path)(struct path_selector *ps, struct dm_path *p); + + /* + * Ask selector to reinstate a path. + */ + int (*reinstate_path)(struct path_selector *ps, struct dm_path *p); + + /* + * Table content based on parameters added in ps_add_path_fn + * or path selector status + */ + int (*status)(struct path_selector *ps, struct dm_path *path, + status_type_t type, char *result, unsigned int maxlen); + + int (*start_io)(struct path_selector *ps, struct dm_path *path, + size_t nr_bytes); + int (*end_io)(struct path_selector *ps, struct dm_path *path, + size_t nr_bytes, u64 start_time); +}; + +/* Register a path selector */ +int dm_register_path_selector(struct path_selector_type *type); + +/* Unregister a path selector */ +void dm_unregister_path_selector(struct path_selector_type *type); + +/* Returns a registered path selector type */ +struct path_selector_type *dm_get_path_selector(const char *name); + +/* Releases a path selector */ +void dm_put_path_selector(struct path_selector_type *pst); + +#endif -- cgit v1.3.1