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authorCheng Lingfei <chenglingfei@foxmail.com>2026-08-24 20:45:46 +0800
committerTejun Heo <tj@kernel.org>2026-08-24 06:55:59 -1000
commit909a3f0e9d8b0d8001cf6e99808f88eca8e44328 (patch)
treebe05d18bd5619b55ff3b30f28a292907021768ee /include/asm-generic/bitops/ffs.h
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docs: cgroup-v2: fix misc.events key format descriptiongrafted
In misc cgroup, misc.events does not output a simple "max" key. Instead, each registered misc resource outputs a separate key suffixed with ".max" (i.e., "<res>.max"). Update the documentation to clarify that the entry key is "<res>.max". Suggested-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/asm-generic/bitops/ffs.h')
-rw-r--r--include/asm-generic/bitops/ffs.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/ffs.h b/include/asm-generic/bitops/ffs.h
new file mode 100644
index 000000000..5ff2b7fbd
--- /dev/null
+++ b/include/asm-generic/bitops/ffs.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FFS_H_
+#define _ASM_GENERIC_BITOPS_FFS_H_
+
+/**
+ * generic_ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from ffz (man ffs).
+ */
+static inline __attribute_const__ int generic_ffs(int x)
+{
+ int r = 1;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+
+#ifndef __HAVE_ARCH_FFS
+#define ffs(x) generic_ffs(x)
+#endif
+
+#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */