diff mbox series

[net-next,3/4] mlxsw: spectrum_router: Apply user-defined multipath hash seed

Message ID 20240529111844.13330-4-petrm@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Allow configuration of multipath hash seed | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 902 this patch: 902
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 906 this patch: 906
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 906 this patch: 906
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 25 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-05-30--06-00 (tests: 1042)

Commit Message

Petr Machata May 29, 2024, 11:18 a.m. UTC 
When Spectrum machines compute hash for the purposes of ECMP routing, they
use a seed specified through RECR_v2 (Router ECMP Configuration Register).
Up until now mlxsw computed the seed by hashing the machine's base MAC.
Now that we can optionally have a user-provided seed, use that if possible.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
---
 .../net/ethernet/mellanox/mlxsw/spectrum_router.c  | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 40ba314fbc72..e5b669f0822d 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -11449,13 +11449,23 @@  static int mlxsw_sp_mp_hash_parsing_depth_adjust(struct mlxsw_sp *mlxsw_sp,
 static int mlxsw_sp_mp_hash_init(struct mlxsw_sp *mlxsw_sp)
 {
 	bool old_inc_parsing_depth, new_inc_parsing_depth;
+	struct sysctl_fib_multipath_hash_seed *mphs;
 	struct mlxsw_sp_mp_hash_config config = {};
+	struct net *net = mlxsw_sp_net(mlxsw_sp);
 	char recr2_pl[MLXSW_REG_RECR2_LEN];
 	unsigned long bit;
-	u32 seed;
+	u32 seed = 0;
 	int err;
 
-	seed = jhash(mlxsw_sp->base_mac, sizeof(mlxsw_sp->base_mac), 0);
+	rcu_read_lock();
+	mphs = rcu_dereference(net->ipv4.sysctl_fib_multipath_hash_seed);
+	if (mphs)
+		seed = mphs->user_seed;
+	rcu_read_unlock();
+
+	if (!seed)
+		seed = jhash(mlxsw_sp->base_mac, sizeof(mlxsw_sp->base_mac), 0);
+
 	mlxsw_reg_recr2_pack(recr2_pl, seed);
 	mlxsw_sp_mp4_hash_init(mlxsw_sp, &config);
 	mlxsw_sp_mp6_hash_init(mlxsw_sp, &config);