Add a BPF iterator for traversing through wakeup_sources.
Setup iterators to traverse through a SRCUs of wakeup_sources. This is a more elegant and efficient traversal than going through the options today, such as at /sys/class/wakeup, or through debugfs.
Signed-off-by: Samuel Wu wusamuel@google.com --- kernel/bpf/Makefile | 3 + kernel/bpf/wakeup_source_iter.c | 103 ++++++++++++++++++++++++++++++++ 2 files changed, 106 insertions(+) create mode 100644 kernel/bpf/wakeup_source_iter.c
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 79cf22860a99..1259373298e1 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -66,6 +66,9 @@ obj-$(CONFIG_BPF_SYSCALL) += kmem_cache_iter.o ifeq ($(CONFIG_DMA_SHARED_BUFFER),y) obj-$(CONFIG_BPF_SYSCALL) += dmabuf_iter.o endif +ifeq ($(CONFIG_PM_SLEEP),y) +obj-$(CONFIG_BPF_SYSCALL) += wakeup_source_iter.o +endif
CFLAGS_REMOVE_percpu_freelist.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_bpf_lru_list.o = $(CC_FLAGS_FTRACE) diff --git a/kernel/bpf/wakeup_source_iter.c b/kernel/bpf/wakeup_source_iter.c new file mode 100644 index 000000000000..ab83d212a1f9 --- /dev/null +++ b/kernel/bpf/wakeup_source_iter.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2026 Google LLC */ +#include <linux/bpf.h> +#include <linux/btf_ids.h> +#include <linux/kernel.h> +#include <linux/pm_wakeup.h> +#include <linux/seq_file.h> + +struct bpf_iter__wakeup_source { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct wakeup_source *, wakeup_source); +}; + +static void *wakeup_source_iter_seq_start(struct seq_file *seq, loff_t *pos) +{ + int *srcuidx = seq->private; + struct wakeup_source *ws; + loff_t i; + + *srcuidx = wakeup_sources_read_lock(); + + ws = wakeup_sources_walk_start(); + for (i = 0; ws && i < *pos; i++) + ws = wakeup_sources_walk_next(ws); + + return ws; +} + +static void *wakeup_source_iter_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct wakeup_source *ws = v; + + ++*pos; + + return wakeup_sources_walk_next(ws); +} + +static void wakeup_source_iter_seq_stop(struct seq_file *seq, void *v) +{ + int *srcuidx = seq->private; + + if (*srcuidx >= 0) + wakeup_sources_read_unlock(*srcuidx); + *srcuidx = -1; +} + +static int __wakeup_source_seq_show(struct seq_file *seq, void *v, bool in_stop) +{ + struct bpf_iter_meta meta = { + .seq = seq, + }; + struct bpf_iter__wakeup_source ctx = { + .meta = &meta, + .wakeup_source = v, + }; + struct bpf_prog *prog = bpf_iter_get_info(&meta, in_stop); + + if (prog) + return bpf_iter_run_prog(prog, &ctx); + + return 0; +} + +static int wakeup_source_iter_seq_show(struct seq_file *seq, void *v) +{ + return __wakeup_source_seq_show(seq, v, false); +} + +static const struct seq_operations wakeup_source_iter_seq_ops = { + .start = wakeup_source_iter_seq_start, + .next = wakeup_source_iter_seq_next, + .stop = wakeup_source_iter_seq_stop, + .show = wakeup_source_iter_seq_show, +}; + +static const struct bpf_iter_seq_info wakeup_source_iter_seq_info = { + .seq_ops = &wakeup_source_iter_seq_ops, + .seq_priv_size = sizeof(int), +}; + +static struct bpf_iter_reg bpf_wakeup_source_reg_info = { + .target = "wakeup_source", + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { + offsetof(struct bpf_iter__wakeup_source, wakeup_source), + PTR_TO_BTF_ID_OR_NULL + }, + }, + .seq_info = &wakeup_source_iter_seq_info, +}; + +DEFINE_BPF_ITER_FUNC(wakeup_source, struct bpf_iter_meta *meta, + struct wakeup_source *wakeup_source) +BTF_ID_LIST_SINGLE(bpf_wakeup_source_btf_id, struct, wakeup_source) + +static int __init wakeup_source_iter_init(void) +{ + bpf_wakeup_source_reg_info.ctx_arg_info[0].btf_id = bpf_wakeup_source_btf_id[0]; + return bpf_iter_reg_target(&bpf_wakeup_source_reg_info); +} + +late_initcall(wakeup_source_iter_init);