libbpf: Add documentation for bpf_map batch operations

This adds documention for:

- bpf_map_delete_batch()
- bpf_map_lookup_batch()
- bpf_map_lookup_and_delete_batch()
- bpf_map_update_batch()

This also updates the public API for the `keys` parameter
of `bpf_map_delete_batch()`, and both the
`keys` and `values` parameters of `bpf_map_update_batch()`
to be constants.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220106201304.112675-1-grantseltzer@gmail.com

1 files changed, 4 insertions, 4 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 9b64eed2b003..550b4cbb6c99 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -691,11 +691,11 @@ static int bpf_map_batch_common(int cmd, int fd, void  *in_batch,
 	return libbpf_err_errno(ret);
 }
 
-int bpf_map_delete_batch(int fd, void *keys, __u32 *count,
+int bpf_map_delete_batch(int fd, const void *keys, __u32 *count,
 			 const struct bpf_map_batch_opts *opts)
 {
 	return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL,
-				    NULL, keys, NULL, count, opts);
+				    NULL, (void *)keys, NULL, count, opts);
 }
 
 int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys,
@@ -715,11 +715,11 @@ int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch,
 				    count, opts);
 }
 
-int bpf_map_update_batch(int fd, void *keys, void *values, __u32 *count,
+int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *count,
 			 const struct bpf_map_batch_opts *opts)
 {
 	return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL,
-				    keys, values, count, opts);
+				    (void *)keys, (void *)values, count, opts);
 }
 
 int bpf_obj_pin(int fd, const char *pathname)