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/base/regmap/regcache-flat.c | 175 ++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 drivers/base/regmap/regcache-flat.c (limited to 'drivers/base/regmap/regcache-flat.c') diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c new file mode 100644 index 000000000..be8497fd2 --- /dev/null +++ b/drivers/base/regmap/regcache-flat.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register cache access API - flat caching support +// +// Copyright 2012 Wolfson Microelectronics plc +// +// Author: Mark Brown + +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +static inline unsigned int regcache_flat_get_index(const struct regmap *map, + unsigned int reg) +{ + return regcache_get_index_by_order(map, reg); +} + +struct regcache_flat_data { + unsigned long *valid; + unsigned int data[]; +}; + +static int regcache_flat_init(struct regmap *map) +{ + unsigned int cache_size; + struct regcache_flat_data *cache; + + if (!map || map->reg_stride_order < 0 || !map->max_register_is_set) + return -EINVAL; + + cache_size = regcache_flat_get_index(map, map->max_register) + 1; + cache = kzalloc_flex(*cache, data, cache_size, map->alloc_flags); + if (!cache) + return -ENOMEM; + + cache->valid = bitmap_zalloc(cache_size, map->alloc_flags); + if (!cache->valid) + goto err_free; + + map->cache = cache; + + return 0; + +err_free: + kfree(cache); + return -ENOMEM; +} + +static void regcache_flat_exit(struct regmap *map) +{ + struct regcache_flat_data *cache = map->cache; + + if (cache) + bitmap_free(cache->valid); + + kfree(cache); + map->cache = NULL; +} + +static int regcache_flat_populate(struct regmap *map) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int i; + + for (i = 0; i < map->num_reg_defaults; i++) { + unsigned int reg = map->reg_defaults[i].reg; + unsigned int index = regcache_flat_get_index(map, reg); + + cache->data[index] = map->reg_defaults[i].def; + __set_bit(index, cache->valid); + } + + if (map->reg_default_cb) { + dev_dbg(map->dev, + "Populating regcache_flat using reg_default_cb callback\n"); + + for (i = 0; i <= map->max_register; i += map->reg_stride) { + unsigned int index = regcache_flat_get_index(map, i); + unsigned int value; + + if (test_bit(index, cache->valid)) + continue; + + if (map->reg_default_cb(map->dev, i, &value)) + continue; + + cache->data[index] = value; + __set_bit(index, cache->valid); + } + } + + return 0; +} + +static int regcache_flat_read(struct regmap *map, + unsigned int reg, unsigned int *value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + /* legacy behavior: ignore validity, but warn the user */ + if (unlikely(!test_bit(index, cache->valid))) + dev_warn_once(map->dev, + "using zero-initialized flat cache, this may cause unexpected behavior"); + + *value = cache->data[index]; + + return 0; +} + +static int regcache_flat_sparse_read(struct regmap *map, + unsigned int reg, unsigned int *value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + if (unlikely(!test_bit(index, cache->valid))) + return -ENOENT; + + *value = cache->data[index]; + + return 0; +} + +static int regcache_flat_write(struct regmap *map, unsigned int reg, + unsigned int value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + cache->data[index] = value; + __set_bit(index, cache->valid); + + return 0; +} + +static int regcache_flat_drop(struct regmap *map, unsigned int min, + unsigned int max) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int bitmap_min = regcache_flat_get_index(map, min); + unsigned int bitmap_max = regcache_flat_get_index(map, max); + + bitmap_clear(cache->valid, bitmap_min, bitmap_max + 1 - bitmap_min); + + return 0; +} + +struct regcache_ops regcache_flat_ops = { + .type = REGCACHE_FLAT, + .name = "flat", + .init = regcache_flat_init, + .exit = regcache_flat_exit, + .populate = regcache_flat_populate, + .read = regcache_flat_read, + .write = regcache_flat_write, +}; + +struct regcache_ops regcache_flat_sparse_ops = { + .type = REGCACHE_FLAT_S, + .name = "flat-sparse", + .init = regcache_flat_init, + .exit = regcache_flat_exit, + .populate = regcache_flat_populate, + .read = regcache_flat_sparse_read, + .write = regcache_flat_write, + .drop = regcache_flat_drop, +}; -- cgit v1.3.1