Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/tools/perf/util/fncache.c b/tools/perf/util/fncache.c
new file mode 100644
index 0000000..6225cbc
--- /dev/null
+++ b/tools/perf/util/fncache.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Manage a cache of file names' existence */
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <linux/list.h>
+#include "fncache.h"
+
+struct fncache {
+ struct hlist_node nd;
+ bool res;
+ char name[];
+};
+
+#define FNHSIZE 61
+
+static struct hlist_head fncache_hash[FNHSIZE];
+
+unsigned shash(const unsigned char *s)
+{
+ unsigned h = 0;
+ while (*s)
+ h = 65599 * h + *s++;
+ return h ^ (h >> 16);
+}
+
+static bool lookup_fncache(const char *name, bool *res)
+{
+ int h = shash((const unsigned char *)name) % FNHSIZE;
+ struct fncache *n;
+
+ hlist_for_each_entry(n, &fncache_hash[h], nd) {
+ if (!strcmp(n->name, name)) {
+ *res = n->res;
+ return true;
+ }
+ }
+ return false;
+}
+
+static void update_fncache(const char *name, bool res)
+{
+ struct fncache *n = malloc(sizeof(struct fncache) + strlen(name) + 1);
+ int h = shash((const unsigned char *)name) % FNHSIZE;
+
+ if (!n)
+ return;
+ strcpy(n->name, name);
+ n->res = res;
+ hlist_add_head(&n->nd, &fncache_hash[h]);
+}
+
+/* No LRU, only use when bounded in some other way. */
+bool file_available(const char *name)
+{
+ bool res;
+
+ if (lookup_fncache(name, &res))
+ return res;
+ res = access(name, R_OK) == 0;
+ update_fncache(name, res);
+ return res;
+}