ice: enable symmetric-xor RSS for Toeplitz hash function

Allow the user to set the symmetric Toeplitz hash function via:

    # ethtool -X eth0 hfunc toeplitz symmetric-xor

All existing RSS configurations will be converted to symmetric unless they
have a non-symmetric field (other than IP src/dst and L4 src/dst ports)
used for hashing. The driver will reject a new RSS configuration if such
a field is requested.

The hash function in the E800 NICs is set per-VSI and a specific AQ
command is needed to modify the hash function. Use the AQ command to
enable setting the symmetric Toeplitz RSS hash function for any VSI
in the new ice_set_rss_hfunc().

When the Symmetric Toeplitz hash function is used, the hardware sets the
input set of the RSS (Toeplitz) algorithm to be the XOR of the fields
index by HSYMM and the fields index by the INSET registers. We use this
to create a symmetric hash by setting the HSYMM registers to point to
their counterparts in the INSET registers:

 HSYMM [src_fv] = dst_fv;
 HSYMM [dst_fv] = src_fv;

where src_fv and dst_fv are the indexes of the protocol's src and dst
fields.

Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Jeff Guo <jia.guo@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Co-developed-by: Ahmed Zaki <ahmed.zaki@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://lore.kernel.org/r/20231213003321.605376-8-ahmed.zaki@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 3ea33947b878..2b3aa37df4f3 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -360,6 +360,7 @@ struct ice_vsi {
 	/* RSS config */
 	u16 rss_table_size;	/* HW RSS table size */
 	u16 rss_size;		/* Allocated RSS queues */
+	u8 rss_hfunc;		/* User configured hash type */
 	u8 *rss_hkey_user;	/* User configured hash keys */
 	u8 *rss_lut_user;	/* User configured lookup table entries */
 	u8 rss_lut_type;	/* used to configure Get/Set RSS LUT AQ call */
@@ -920,6 +921,7 @@ int ice_set_rss_lut(struct ice_vsi *vsi, u8 *lut, u16 lut_size);
 int ice_get_rss_lut(struct ice_vsi *vsi, u8 *lut, u16 lut_size);
 int ice_set_rss_key(struct ice_vsi *vsi, u8 *seed);
 int ice_get_rss_key(struct ice_vsi *vsi, u8 *seed);
+int ice_set_rss_hfunc(struct ice_vsi *vsi, u8 hfunc);
 void ice_fill_rss_lut(u8 *lut, u16 rss_table_size, u16 rss_size);
 int ice_schedule_reset(struct ice_pf *pf, enum ice_reset_req reset);
 void ice_print_link_msg(struct ice_vsi *vsi, bool isup);