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 --- tools/perf/util/mem2node.c | 139 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 tools/perf/util/mem2node.c (limited to 'tools/perf/util/mem2node.c') diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c new file mode 100644 index 000000000..51a2292cb --- /dev/null +++ b/tools/perf/util/mem2node.c @@ -0,0 +1,139 @@ +#include +#include +#include +#include +#include +#include +#include "debug.h" +#include "env.h" +#include "mem2node.h" + +struct phys_entry { + struct rb_node rb_node; + u64 start; + u64 end; + u64 node; +}; + +static void phys_entry__insert(struct phys_entry *entry, struct rb_root *root) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct phys_entry *e; + + while (*p != NULL) { + parent = *p; + e = rb_entry(parent, struct phys_entry, rb_node); + + if (entry->start < e->start) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + rb_link_node(&entry->rb_node, parent, p); + rb_insert_color(&entry->rb_node, root); +} + +static void +phys_entry__init(struct phys_entry *entry, u64 start, u64 bsize, u64 node) +{ + entry->start = start; + entry->end = start + bsize; + entry->node = node; + RB_CLEAR_NODE(&entry->rb_node); +} + +int mem2node__init(struct mem2node *map, struct perf_env *env) +{ + struct memory_node *n, *nodes = &env->memory_nodes[0]; + struct phys_entry *entries, *tmp_entries; + u64 bsize = env->memory_bsize; + int i, j = 0, max = 0; + + memset(map, 0x0, sizeof(*map)); + map->root = RB_ROOT; + + for (i = 0; i < env->nr_memory_nodes; i++) { + n = &nodes[i]; + max += bitmap_weight(n->set, n->size); + } + + entries = calloc(max, sizeof(*entries)); + if (!entries) + return -ENOMEM; + + for (i = 0; i < env->nr_memory_nodes; i++) { + u64 bit; + + n = &nodes[i]; + + for (bit = 0; bit < n->size; bit++) { + u64 start; + + if (!test_bit(bit, n->set)) + continue; + + start = bit * bsize; + + /* + * Merge nearby areas, we walk in order + * through the bitmap, so no need to sort. + */ + if (j > 0) { + struct phys_entry *prev = &entries[j - 1]; + + if ((prev->end == start) && + (prev->node == n->node)) { + prev->end += bsize; + continue; + } + } + + phys_entry__init(&entries[j++], start, bsize, n->node); + } + } + + /* Cut unused entries, due to merging. */ + tmp_entries = realloc(entries, sizeof(*entries) * j); + if (tmp_entries || + WARN_ONCE(j == 0, "No memory nodes, is CONFIG_MEMORY_HOTPLUG enabled?\n")) + entries = tmp_entries; + + for (i = 0; i < j; i++) { + pr_debug("mem2node %03" PRIu64 " [0x%016" PRIx64 "-0x%016" PRIx64 "]\n", + entries[i].node, entries[i].start, entries[i].end); + + phys_entry__insert(&entries[i], &map->root); + } + + map->entries = entries; + return 0; +} + +void mem2node__exit(struct mem2node *map) +{ + zfree(&map->entries); +} + +int mem2node__node(struct mem2node *map, u64 addr) +{ + struct rb_node **p, *parent = NULL; + struct phys_entry *entry; + + p = &map->root.rb_node; + while (*p != NULL) { + parent = *p; + entry = rb_entry(parent, struct phys_entry, rb_node); + if (addr < entry->start) + p = &(*p)->rb_left; + else if (addr >= entry->end) + p = &(*p)->rb_right; + else + goto out; + } + + entry = NULL; +out: + return entry ? (int) entry->node : -1; +} -- cgit v1.3.1