Merge branch 'mlxsw-spectrum_acl-Include-delta-bits-into-hashtable-key'

Ido Schimmel says:

====================
mlxsw: spectrum_acl: Include delta bits into hashtable key

The Spectrum-2 ASIC allows multiple rules to use the same mask provided
that the difference between their masks is small enough (up to 8
consecutive delta bits). A more detailed explanation is provided in
merge commit 756cd36626f7 ("Merge branch
'mlxsw-Introduce-algorithmic-TCAM-support'").

These delta bits are part of the rule's key and therefore rules that
only differ in their delta bits can be inserted with the same A-TCAM
mask. In case two rules share the same key and only differ in their
priority, then the second will spill to the C-TCAM.

Current code does not take the delta bits into account when checking for
duplicate rules, which leads to unnecessary spillage to the C-TCAM.
This may result in reduced scale and performance.

Patch #1 includes the delta bits in the rule's key to avoid the above
mentioned problem.

Patch #2 adds a tracepoint when a rule is inserted into the C-TCAM.

Patches #3-#5 add test cases to make sure unnecessary spillage into the
C-TCAM does not occur.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 20 insertions, 16 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_atcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_atcam.c
index 40dc76a5c412..a74a390901ac 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_atcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_atcam.c
@@ -7,6 +7,8 @@
 #include <linux/gfp.h>
 #include <linux/refcount.h>
 #include <linux/rhashtable.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/mlxsw.h>
 
 #include "reg.h"
 #include "core.h"
@@ -390,8 +392,7 @@ mlxsw_sp_acl_atcam_region_entry_insert(struct mlxsw_sp *mlxsw_sp,
 	if (err)
 		return err;
 
-	lkey_id = aregion->ops->lkey_id_get(aregion, aentry->ht_key.enc_key,
-					    erp_id);
+	lkey_id = aregion->ops->lkey_id_get(aregion, aentry->enc_key, erp_id);
 	if (IS_ERR(lkey_id))
 		return PTR_ERR(lkey_id);
 	aentry->lkey_id = lkey_id;
@@ -399,7 +400,7 @@ mlxsw_sp_acl_atcam_region_entry_insert(struct mlxsw_sp *mlxsw_sp,
 	kvdl_index = mlxsw_afa_block_first_kvdl_index(rulei->act_block);
 	mlxsw_reg_ptce3_pack(ptce3_pl, true, MLXSW_REG_PTCE3_OP_WRITE_WRITE,
 			     priority, region->tcam_region_info,
-			     aentry->ht_key.enc_key, erp_id,
+			     aentry->enc_key, erp_id,
 			     aentry->delta_info.start,
 			     aentry->delta_info.mask,
 			     aentry->delta_info.value,
@@ -424,12 +425,11 @@ mlxsw_sp_acl_atcam_region_entry_remove(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_acl_atcam_lkey_id *lkey_id = aentry->lkey_id;
 	struct mlxsw_sp_acl_tcam_region *region = aregion->region;
 	u8 erp_id = mlxsw_sp_acl_erp_mask_erp_id(aentry->erp_mask);
-	char *enc_key = aentry->ht_key.enc_key;
 	char ptce3_pl[MLXSW_REG_PTCE3_LEN];
 
 	mlxsw_reg_ptce3_pack(ptce3_pl, false, MLXSW_REG_PTCE3_OP_WRITE_WRITE, 0,
 			     region->tcam_region_info,
-			     enc_key, erp_id,
+			     aentry->enc_key, erp_id,
 			     aentry->delta_info.start,
 			     aentry->delta_info.mask,
 			     aentry->delta_info.value,
@@ -458,7 +458,7 @@ mlxsw_sp_acl_atcam_region_entry_action_replace(struct mlxsw_sp *mlxsw_sp,
 	kvdl_index = mlxsw_afa_block_first_kvdl_index(rulei->act_block);
 	mlxsw_reg_ptce3_pack(ptce3_pl, true, MLXSW_REG_PTCE3_OP_WRITE_UPDATE,
 			     priority, region->tcam_region_info,
-			     aentry->ht_key.enc_key, erp_id,
+			     aentry->enc_key, erp_id,
 			     aentry->delta_info.start,
 			     aentry->delta_info.mask,
 			     aentry->delta_info.value,
@@ -481,15 +481,15 @@ __mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 	int err;
 
 	mlxsw_afk_encode(afk, region->key_info, &rulei->values,
-			 aentry->full_enc_key, mask);
+			 aentry->ht_key.full_enc_key, mask);
 
 	erp_mask = mlxsw_sp_acl_erp_mask_get(aregion, mask, false);
 	if (IS_ERR(erp_mask))
 		return PTR_ERR(erp_mask);
 	aentry->erp_mask = erp_mask;
 	aentry->ht_key.erp_id = mlxsw_sp_acl_erp_mask_erp_id(erp_mask);
-	memcpy(aentry->ht_key.enc_key, aentry->full_enc_key,
-	       sizeof(aentry->ht_key.enc_key));
+	memcpy(aentry->enc_key, aentry->ht_key.full_enc_key,
+	       sizeof(aentry->enc_key));
 
 	/* Compute all needed delta information and clear the delta bits
 	 * from the encrypted key.
@@ -498,8 +498,9 @@ __mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 	aentry->delta_info.start = mlxsw_sp_acl_erp_delta_start(delta);
 	aentry->delta_info.mask = mlxsw_sp_acl_erp_delta_mask(delta);
 	aentry->delta_info.value =
-		mlxsw_sp_acl_erp_delta_value(delta, aentry->full_enc_key);
-	mlxsw_sp_acl_erp_delta_clear(delta, aentry->ht_key.enc_key);
+		mlxsw_sp_acl_erp_delta_value(delta,
+					     aentry->ht_key.full_enc_key);
+	mlxsw_sp_acl_erp_delta_clear(delta, aentry->enc_key);
 
 	/* Add rule to the list of A-TCAM rules, assuming this
 	 * rule is intended to A-TCAM. In case this rule does
@@ -579,6 +580,7 @@ int mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 	/* It is possible we failed to add the rule to the A-TCAM due to
 	 * exceeded number of masks. Try to spill into C-TCAM.
 	 */
+	trace_mlxsw_sp_acl_atcam_entry_add_ctcam_spill(mlxsw_sp, aregion);
 	err = mlxsw_sp_acl_ctcam_entry_add(mlxsw_sp, &aregion->cregion,
 					   &achunk->cchunk, &aentry->centry,
 					   rulei, true);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
index f5c381dcb015..9545b572747e 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
@@ -133,7 +133,7 @@ mlxsw_sp_acl_bf_key_encode(struct mlxsw_sp_acl_atcam_region *aregion,
 		memcpy(chunk + MLXSW_BLOOM_CHUNK_PAD_BYTES, &erp_region_id,
 		       sizeof(erp_region_id));
 		memcpy(chunk + MLXSW_BLOOM_CHUNK_KEY_OFFSET,
-		       &aentry->ht_key.enc_key[chunk_key_offsets[chunk_index]],
+		       &aentry->enc_key[chunk_key_offsets[chunk_index]],
 		       MLXSW_BLOOM_CHUNK_KEY_BYTES);
 		chunk += MLXSW_BLOOM_KEY_CHUNK_BYTES;
 	}
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
index 10512b7c6d50..0858d5b06353 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
@@ -161,9 +161,9 @@ struct mlxsw_sp_acl_atcam_region {
 };
 
 struct mlxsw_sp_acl_atcam_entry_ht_key {
-	char enc_key[MLXSW_REG_PTCEX_FLEX_KEY_BLOCKS_LEN]; /* Encoded key,
-							    * minus delta bits.
-							    */
+	char full_enc_key[MLXSW_REG_PTCEX_FLEX_KEY_BLOCKS_LEN]; /* Encoded
+								 * key.
+								 */
 	u8 erp_id;
 };
 
@@ -175,7 +175,9 @@ struct mlxsw_sp_acl_atcam_entry {
 	struct rhash_head ht_node;
 	struct list_head list; /* Member in entries_list */
 	struct mlxsw_sp_acl_atcam_entry_ht_key ht_key;
-	char full_enc_key[MLXSW_REG_PTCEX_FLEX_KEY_BLOCKS_LEN]; /* Encoded key */
+	char enc_key[MLXSW_REG_PTCEX_FLEX_KEY_BLOCKS_LEN]; /* Encoded key,
+							    * minus delta bits.
+							    */
 	struct {
 		u16 start;
 		u8 mask;