Add bpf prog attach helpers and prepare for supporting ublk bpf, in which
multiple ublk device may attach to same bpf prog, and there can be
multiple bpf progs.
`bpf_prog_consumer` will be embedded in the bpf prog user side, such as
ublk device, `bpf_prog_provider` will be embedded in the bpf struct_ops
prog side.
Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
drivers/block/ublk/bpf_reg.h | 77 ++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)
create mode 100644 drivers/block/ublk/bpf_reg.h
diff --git a/drivers/block/ublk/bpf_reg.h b/drivers/block/ublk/bpf_reg.h
new file mode 100644
index 000000000000..79d02e93aea8
--- /dev/null
+++ b/drivers/block/ublk/bpf_reg.h
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef UBLK_INT_BPF_REG_HEADER
+#define UBLK_INT_BPF_REG_HEADER
+
+#include <linux/types.h>
+
+struct bpf_prog_consumer;
+struct bpf_prog_provider;
+
+typedef int (*bpf_prog_attach_t)(struct bpf_prog_consumer *consumer,
+ struct bpf_prog_provider *provider);
+typedef void (*bpf_prog_detach_t)(struct bpf_prog_consumer *consumer,
+ bool unreg);
+
+struct bpf_prog_consumer_ops {
+ bpf_prog_attach_t attach_fn;
+ bpf_prog_detach_t detach_fn;
+};
+
+struct bpf_prog_consumer {
+ const struct bpf_prog_consumer_ops *ops;
+ unsigned int prog_id;
+ struct list_head node;
+ struct bpf_prog_provider *provider;
+};
+
+struct bpf_prog_provider {
+ struct list_head list;
+};
+
+static inline void bpf_prog_provider_init(struct bpf_prog_provider *provider)
+{
+ INIT_LIST_HEAD(&provider->list);
+}
+
+static inline bool bpf_prog_provider_is_empty(
+ struct bpf_prog_provider *provider)
+{
+ return list_empty(&provider->list);
+}
+
+static inline int bpf_prog_consumer_attach(struct bpf_prog_consumer *consumer,
+ struct bpf_prog_provider *provider)
+{
+ const struct bpf_prog_consumer_ops *ops = consumer->ops;
+
+ if (!ops || !ops->attach_fn)
+ return -EINVAL;
+
+ if (ops->attach_fn) {
+ int ret = ops->attach_fn(consumer, provider);
+
+ if (ret)
+ return ret;
+ }
+ consumer->provider = provider;
+ list_add(&consumer->node, &provider->list);
+ return 0;
+}
+
+static inline void bpf_prog_consumer_detach(struct bpf_prog_consumer *consumer,
+ bool unreg)
+{
+ const struct bpf_prog_consumer_ops *ops = consumer->ops;
+
+ if (!consumer->provider)
+ return;
+
+ if (!list_empty(&consumer->node)) {
+ if (ops && ops->detach_fn)
+ ops->detach_fn(consumer, unreg);
+ list_del_init(&consumer->node);
+ consumer->provider = NULL;
+ }
+}
+
+#endif
--
2.47.0
