[v2,11/13] ip_tunnel: convert __be16 tunnel flags to bitmaps

From: Yury Norov <yury.norov@gmail.com>

Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT
have been defined as __be16. Now all of those 16 bits are occupied
and there's no more free space for new flags.
It can't be simply switched to a bigger container with no
adjustments to the values, since it's an explicit Endian storage,
and on LE systems (__be16)0x0001 equals to
(__be64)0x0001000000000000.
We could probably define new 64-bit flags depending on the
Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on
LE, but that would introduce an Endianness dependency and spawn a
ton of Sparse warnings. To mitigate them, all of those places which
were adjusted with this change would be touched anyway, so why not
define stuff properly if there's no choice.

Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the
value already coded and a fistful of <16 <-> bitmap> converters and
helpers. The two flags which have a different bit position are
SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as
__cpu_to_be16(), but as (__force __be16), i.e. had different
positions on LE and BE. Now they both have strongly defined places.
Change all __be16 fields which were used to store those flags, to
IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) ->
unsigned long[1] for now, and replace all TUNNEL_* occurrences to
their bitmap counterparts. Use the converters in the places which talk
to the userspace, hardware (NFP) or other hosts (GRE header). The rest
must explicitly use the new flags only. This must be done at once,
otherwise there will be too many conversions throughout the code in
the intermediate commits.
Finally, disable the old __be16 flags for use in the kernel code
(except for the two 'irregular' flags mentioned above), to prevent
any accidental (mis)use of them. For the userspace, nothing is
changed, only additions were made.

Most noticeable bloat-o-meter difference (.text):

vmlinux:	307/-1 (306)
gre.ko:		62/0 (62)
ip_gre.ko:	941/-217 (724)	[*]
ip_tunnel.ko:	390/-900 (-510)	[**]
ip_vti.ko:	138/0 (138)
ip6_gre.ko:	534/-18 (516)	[*]
ip6_tunnel.ko:	118/-10 (108)

[*] gre_flags_to_tnl_flags() grew, but still is inlined
[**] ip_tunnel_find() got uninlined, hence such decrease

The average code size increase in non-extreme case is 100-200 bytes
per module, mostly due to sizeof(long) > sizeof(__be16), as
%__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers
are able to expand the majority of bitmap_*() calls here into direct
operations on scalars.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/bareudp.c                         |  19 ++-
 .../ethernet/mellanox/mlx5/core/en/tc_tun.h   |   2 +-
 .../mellanox/mlx5/core/en/tc_tun_encap.c      |   6 +-
 .../mellanox/mlx5/core/en/tc_tun_geneve.c     |  12 +-
 .../mellanox/mlx5/core/en/tc_tun_gre.c        |   8 +-
 .../mellanox/mlx5/core/en/tc_tun_vxlan.c      |   9 +-
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   |  16 ++-
 .../ethernet/mellanox/mlxsw/spectrum_ipip.c   |  26 ++--
 .../ethernet/mellanox/mlxsw/spectrum_span.c   |   6 +-
 .../ethernet/netronome/nfp/flower/action.c    |  27 +++-
 drivers/net/geneve.c                          |  44 +++---
 drivers/net/vxlan/vxlan_core.c                |  14 +-
 include/net/dst_metadata.h                    |  10 +-
 include/net/flow_dissector.h                  |   2 +-
 include/net/gre.h                             |  70 +++++-----
 include/net/ip6_tunnel.h                      |   4 +-
 include/net/ip_tunnels.h                      | 119 +++++++++++++---
 include/net/udp_tunnel.h                      |   4 +-
 include/uapi/linux/if_tunnel.h                |  33 +++++
 net/bridge/br_vlan_tunnel.c                   |   9 +-
 net/core/filter.c                             |  26 ++--
 net/core/flow_dissector.c                     |  20 ++-
 net/ipv4/fou_bpf.c                            |   2 +-
 net/ipv4/gre_demux.c                          |   2 +-
 net/ipv4/ip_gre.c                             | 127 +++++++++++-------
 net/ipv4/ip_tunnel.c                          |  54 ++++----
 net/ipv4/ip_tunnel_core.c                     |  80 ++++++-----
 net/ipv4/ip_vti.c                             |  29 ++--
 net/ipv4/ipip.c                               |  21 ++-
 net/ipv4/udp_tunnel_core.c                    |   5 +-
 net/ipv6/ip6_gre.c                            |  85 +++++++-----
 net/ipv6/ip6_tunnel.c                         |  14 +-
 net/ipv6/sit.c                                |   5 +-
 net/netfilter/ipvs/ip_vs_core.c               |   6 +-
 net/netfilter/ipvs/ip_vs_xmit.c               |  20 +--
 net/netfilter/nft_tunnel.c                    |  44 +++---
 net/openvswitch/flow_netlink.c                |  61 +++++----
 net/psample/psample.c                         |  26 ++--
 net/sched/act_tunnel_key.c                    |  36 ++---
 net/sched/cls_flower.c                        |  27 ++--
 40 files changed, 715 insertions(+), 415 deletions(-)

Message ID	20231016165247.14212-12-aleksander.lobakin@intel.com (mailing list archive)
State	Changes Requested
Delegated to:	Netdev Maintainers
Headers	show Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2715930FA3 for <netdev@vger.kernel.org>; Mon, 16 Oct 2023 16:55:12 +0000 (UTC) From: Alexander Lobakin <aleksander.lobakin@intel.com> To: Yury Norov <yury.norov@gmail.com> Cc: Alexander Lobakin <aleksander.lobakin@intel.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, Alexander Potapenko <glider@google.com>, Jakub Kicinski <kuba@kernel.org>, Eric Dumazet <edumazet@google.com>, David Ahern <dsahern@kernel.org>, Przemek Kitszel <przemyslaw.kitszel@intel.com>, Simon Horman <simon.horman@corigine.com>, netdev@vger.kernel.org, linux-btrfs@vger.kernel.org, dm-devel@redhat.com, ntfs3@lists.linux.dev, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 11/13] ip_tunnel: convert __be16 tunnel flags to bitmaps Date: Mon, 16 Oct 2023 18:52:45 +0200 Message-ID: <20231016165247.14212-12-aleksander.lobakin@intel.com> In-Reply-To: <20231016165247.14212-1-aleksander.lobakin@intel.com> References: <20231016165247.14212-1-aleksander.lobakin@intel.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	ip_tunnel: convert __be16 tunnel flags to bitmaps \| expand [v2,00/13] ip_tunnel: convert __be16 tunnel flags to bitmaps [v2,01/13] bitops: add missing prototype check [v2,02/13] bitops: make BYTES_TO_BITS() treewide-available [v2,03/13] bitops: let the compiler optimize {__,}assign_bit() [v2,04/13] linkmode: convert linkmode_{test,set,clear,mod}_bit() to macros [v2,05/13] s390/cio: rename bitmap_size() -> idset_bitmap_size() [v2,06/13] fs/ntfs3: add prefix to bitmap_size() and use BITS_TO_U64() [v2,07/13] btrfs: rename bitmap_set_bits() -> btrfs_bitmap_set_bits() [v2,08/13] bitmap: introduce generic optimized bitmap_size() [v2,09/13] bitmap: make bitmap_{get,set}_value8() use bitmap_{read,write}() [v2,10/13] ip_tunnel: use a separate struct to store tunnel params in the kernel [v2,11/13] ip_tunnel: convert __be16 tunnel flags to bitmaps [v2,12/13] lib/bitmap: add compile-time test for __assign_bit() optimization [v2,13/13] lib/bitmap: add tests for IP tunnel flags conversion helpers

Context	Check	Description
bpf/vmtest-bpf-PR	fail	merge-conflict
netdev/tree_selection	success	Guessing tree name failed - patch did not apply, async

[v2,11/13] ip_tunnel: convert __be16 tunnel flags to bitmaps

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