Merge branch 'devmap_hash'

Toke Høiland-Jørgensen says:

====================
This series adds a new map type, devmap_hash, that works like the existing
devmap type, but using a hash-based indexing scheme. This is useful for the use
case where a devmap is indexed by ifindex (for instance for use with the routing
table lookup helper). For this use case, the regular devmap needs to be sized
after the maximum ifindex number, not the number of devices in it. A hash-based
indexing scheme makes it possible to size the map after the number of devices it
should contain instead.

This was previously part of my patch series that also turned the regular
bpf_redirect() helper into a map-based one; for this series I just pulled out
the patches that introduced the new map type.

Changelog:

v5:

- Dynamically set the number of hash buckets by rounding up max_entries to the
  nearest power of two (mirroring the regular hashmap), as suggested by Jesper.

v4:

- Remove check_memlock parameter that was left over from an earlier patch
  series.
- Reorder struct members to avoid holes.

v3:

- Rework the split into different patches
- Use spin_lock_irqsave()
- Also add documentation and bash completion definitions for bpftool

v2:

- Split commit adding the new map type so uapi and tools changes are separate.

Changes to these patches since the previous series:

- Rebase on top of the other devmap changes (makes this one simpler!)
- Don't enforce key==val, but allow arbitrary indexes.
- Rename the type to devmap_hash to reflect the fact that it's just a hashmap now.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

3 files changed, 5 insertions, 4 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 490b4501cb6e..61d1d270eb5e 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -46,7 +46,7 @@ MAP COMMANDS
 |	*TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**
 |		| **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash**
 |		| **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps**
-|		| **devmap** | **sockmap** | **cpumap** | **xskmap** | **sockhash**
+|		| **devmap** | **devmap_hash** | **sockmap** | **cpumap** | **xskmap** | **sockhash**
 |		| **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage**
 |		| **queue** | **stack** }
 
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index c8f42e1fcbc9..6b961a5ed100 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -489,8 +489,8 @@ _bpftool()
                                 perf_event_array percpu_hash percpu_array \
                                 stack_trace cgroup_array lru_hash \
                                 lru_percpu_hash lpm_trie array_of_maps \
-                                hash_of_maps devmap sockmap cpumap xskmap \
-                                sockhash cgroup_storage reuseport_sockarray \
+                                hash_of_maps devmap devmap_hash sockmap cpumap \
+                                xskmap sockhash cgroup_storage reuseport_sockarray \
                                 percpu_cgroup_storage queue stack' -- \
                                                    "$cur" ) )
                             return 0
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 5da5a7311f13..bfbbc6b4cb83 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -37,6 +37,7 @@ const char * const map_type_name[] = {
 	[BPF_MAP_TYPE_ARRAY_OF_MAPS]		= "array_of_maps",
 	[BPF_MAP_TYPE_HASH_OF_MAPS]		= "hash_of_maps",
 	[BPF_MAP_TYPE_DEVMAP]			= "devmap",
+	[BPF_MAP_TYPE_DEVMAP_HASH]		= "devmap_hash",
 	[BPF_MAP_TYPE_SOCKMAP]			= "sockmap",
 	[BPF_MAP_TYPE_CPUMAP]			= "cpumap",
 	[BPF_MAP_TYPE_XSKMAP]			= "xskmap",
@@ -1271,7 +1272,7 @@ static int do_help(int argc, char **argv)
 		"       TYPE := { hash | array | prog_array | perf_event_array | percpu_hash |\n"
 		"                 percpu_array | stack_trace | cgroup_array | lru_hash |\n"
 		"                 lru_percpu_hash | lpm_trie | array_of_maps | hash_of_maps |\n"
-		"                 devmap | sockmap | cpumap | xskmap | sockhash |\n"
+		"                 devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n"
 		"                 cgroup_storage | reuseport_sockarray | percpu_cgroup_storage }\n"
 		"       " HELP_SPEC_OPTIONS "\n"
 		"",