Merge branch 'mlxsw-spectrum_acl-Add-Bloom-filter-support'

Ido Schimmel says:

====================
mlxsw: spectrum_acl: Add Bloom filter support

Nir says:

Spectrum-2 uses Bloom filter to reduce the number of lookups in the
algorithmic TCAM (A-TCAM). HW performs multiple exact match lookups in a
given region using a key composed of { packet & mask, mask ID, region ID }.
The masks which are used in a region are called rule patterns or RP.
When such multiple masks are used, the A-TCAM region uses an eRP
(extended RP) table that describes which rule patterns are in use and
defines the order of the lookup. When eRP table is used in a region, one
way to reduce the number of the lookups is to consult a Bloom filter
before doing the lookup.

A Bloom filter is a space-efficient probabilistic data structure, on
which a query returns either "possibly in set" or "definitely not in
set". HW can skip a lookup if a query on the Bloom filter results a
"definitely not set" response. The mlxsw driver implements a "counting
filter" and when either a new entry is marked or the last entry is
removed it will update the HW. Update of this counting filter occurs
when rule is configured or deleted from a region.

Patch #1 adds PEABFE register which is used for setting Bloom filter
entries.

Patch #2 adds Bloom filter resources.

Patch #3 and patch #4 provide Bloom filter handling within mlxsw, by
adding initialization and logic for updating the Bloom bit vector in HW.

Patch #5 and patch #6 add required calls for Bloom filter update as part
of rule configuration flow.

Patch #7 handles transitions to and from eRP table. It uses a list to
keep A-TCAM rules in order to update rules in Bloom filter, in cases of
transitions from master mask based A-TCAM region to an eRP table based
region and vice versa.

Patch #8 removes a trick done on master RP index to a remaining RP,
since Bloom filter is updated on eRP transitions.

Finally, patch #9 activates Bloom filter mechanism in HW, by cancelling
the bypass that was configured before and the remaining three patches
are selftests that exercise the new code.
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -20,7 +20,7 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_acl_tcam.o spectrum_acl_ctcam.o \
 				   spectrum_acl_atcam.o spectrum_acl_erp.o \
 				   spectrum1_acl_tcam.o spectrum2_acl_tcam.o \
-				   spectrum_acl.o \
+				   spectrum_acl_bloom_filter.o spectrum_acl.o \
 				   spectrum_flower.o spectrum_cnt.o \
 				   spectrum_fid.o spectrum_ipip.o \
 				   spectrum_acl_flex_actions.o \

drivers/net/ethernet/mellanox/mlxsw/reg.h

@@ -2743,7 +2743,7 @@ mlxsw_reg_perpt_pack(char *payload, u8 erpt_bank, u8 erpt_index,
 	mlxsw_reg_perpt_erpt_bank_set(payload, erpt_bank);
 	mlxsw_reg_perpt_erpt_index_set(payload, erpt_index);
 	mlxsw_reg_perpt_key_size_set(payload, key_size);
-	mlxsw_reg_perpt_bf_bypass_set(payload, true);
+	mlxsw_reg_perpt_bf_bypass_set(payload, false);
 	mlxsw_reg_perpt_erp_id_set(payload, erp_id);
 	mlxsw_reg_perpt_erpt_base_bank_set(payload, erpt_base_bank);
 	mlxsw_reg_perpt_erpt_base_index_set(payload, erpt_base_index);
@@ -3006,7 +3006,7 @@ static inline void mlxsw_reg_percr_pack(char *payload, u16 region_id)
 	mlxsw_reg_percr_region_id_set(payload, region_id);
 	mlxsw_reg_percr_atcam_ignore_prune_set(payload, false);
 	mlxsw_reg_percr_ctcam_ignore_prune_set(payload, false);
-	mlxsw_reg_percr_bf_bypass_set(payload, true);
+	mlxsw_reg_percr_bf_bypass_set(payload, false);
 }
 
 /* PERERP - Policy-Engine Region eRP Register
@@ -3095,6 +3095,72 @@ static inline void mlxsw_reg_pererp_pack(char *payload, u16 region_id,
 	mlxsw_reg_pererp_master_rp_id_set(payload, master_rp_id);
 }
 
+/* PEABFE - Policy-Engine Algorithmic Bloom Filter Entries Register
+ * ----------------------------------------------------------------
+ * This register configures the Bloom filter entries.
+ */
+#define MLXSW_REG_PEABFE_ID 0x3022
+#define MLXSW_REG_PEABFE_BASE_LEN 0x10
+#define MLXSW_REG_PEABFE_BF_REC_LEN 0x4
+#define MLXSW_REG_PEABFE_BF_REC_MAX_COUNT 256
+#define MLXSW_REG_PEABFE_LEN (MLXSW_REG_PEABFE_BASE_LEN + \
+			      MLXSW_REG_PEABFE_BF_REC_LEN * \
+			      MLXSW_REG_PEABFE_BF_REC_MAX_COUNT)
+
+MLXSW_REG_DEFINE(peabfe, MLXSW_REG_PEABFE_ID, MLXSW_REG_PEABFE_LEN);
+
+/* reg_peabfe_size
+ * Number of BF entries to be updated.
+ * Range 1..256
+ * Access: Op
+ */
+MLXSW_ITEM32(reg, peabfe, size, 0x00, 0, 9);
+
+/* reg_peabfe_bf_entry_state
+ * Bloom filter state
+ * 0 - Clear
+ * 1 - Set
+ * Access: RW
+ */
+MLXSW_ITEM32_INDEXED(reg, peabfe, bf_entry_state,
+		     MLXSW_REG_PEABFE_BASE_LEN,	31, 1,
+		     MLXSW_REG_PEABFE_BF_REC_LEN, 0x00, false);
+
+/* reg_peabfe_bf_entry_bank
+ * Bloom filter bank ID
+ * Range 0..cap_max_erp_table_banks-1
+ * Access: Index
+ */
+MLXSW_ITEM32_INDEXED(reg, peabfe, bf_entry_bank,
+		     MLXSW_REG_PEABFE_BASE_LEN,	24, 4,
+		     MLXSW_REG_PEABFE_BF_REC_LEN, 0x00, false);
+
+/* reg_peabfe_bf_entry_index
+ * Bloom filter entry index
+ * Range 0..2^cap_max_bf_log-1
+ * Access: Index
+ */
+MLXSW_ITEM32_INDEXED(reg, peabfe, bf_entry_index,
+		     MLXSW_REG_PEABFE_BASE_LEN,	0, 24,
+		     MLXSW_REG_PEABFE_BF_REC_LEN, 0x00, false);
+
+static inline void mlxsw_reg_peabfe_pack(char *payload)
+{
+	MLXSW_REG_ZERO(peabfe, payload);
+}
+
+static inline void mlxsw_reg_peabfe_rec_pack(char *payload, int rec_index,
+					     u8 state, u8 bank, u32 bf_index)
+{
+	u8 num_rec = mlxsw_reg_peabfe_size_get(payload);
+
+	if (rec_index >= num_rec)
+		mlxsw_reg_peabfe_size_set(payload, rec_index + 1);
+	mlxsw_reg_peabfe_bf_entry_state_set(payload, rec_index, state);
+	mlxsw_reg_peabfe_bf_entry_bank_set(payload, rec_index, bank);
+	mlxsw_reg_peabfe_bf_entry_index_set(payload, rec_index, bf_index);
+}
+
 /* IEDR - Infrastructure Entry Delete Register
  * ----------------------------------------------------
  * This register is used for deleting entries from the entry tables.
@@ -9608,6 +9674,7 @@ static const struct mlxsw_reg_info *mlxsw_reg_infos[] = {
 	MLXSW_REG(pemrbt),
 	MLXSW_REG(ptce2),
 	MLXSW_REG(perpt),
+	MLXSW_REG(peabfe),
 	MLXSW_REG(perar),
 	MLXSW_REG(ptce3),
 	MLXSW_REG(percr),

drivers/net/ethernet/mellanox/mlxsw/resources.h

@@ -41,6 +41,7 @@ enum mlxsw_res_id {
 	MLXSW_RES_ID_ACL_ERPT_ENTRIES_4KB,
 	MLXSW_RES_ID_ACL_ERPT_ENTRIES_8KB,
 	MLXSW_RES_ID_ACL_ERPT_ENTRIES_12KB,
+	MLXSW_RES_ID_ACL_MAX_BF_LOG,
 	MLXSW_RES_ID_MAX_CPU_POLICERS,
 	MLXSW_RES_ID_MAX_VRS,
 	MLXSW_RES_ID_MAX_RIFS,
@@ -93,6 +94,7 @@ static u16 mlxsw_res_ids[] = {
 	[MLXSW_RES_ID_ACL_ERPT_ENTRIES_4KB] = 0x2951,
 	[MLXSW_RES_ID_ACL_ERPT_ENTRIES_8KB] = 0x2952,
 	[MLXSW_RES_ID_ACL_ERPT_ENTRIES_12KB] = 0x2953,
+	[MLXSW_RES_ID_ACL_MAX_BF_LOG] = 0x2960,
 	[MLXSW_RES_ID_MAX_CPU_POLICERS] = 0x2A13,
 	[MLXSW_RES_ID_MAX_VRS] = 0x2C01,
 	[MLXSW_RES_ID_MAX_RIFS] = 0x2C02,

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_atcam.c

@@ -323,6 +323,7 @@ mlxsw_sp_acl_atcam_region_init(struct mlxsw_sp *mlxsw_sp,
 	aregion->region = region;
 	aregion->atcam = atcam;
 	mlxsw_sp_acl_atcam_region_type_init(aregion);
+	INIT_LIST_HEAD(&aregion->entries_list);
 
 	err = rhashtable_init(&aregion->entries_ht,
 			      &mlxsw_sp_acl_atcam_entries_ht_params);
@@ -356,6 +357,7 @@ void mlxsw_sp_acl_atcam_region_fini(struct mlxsw_sp_acl_atcam_region *aregion)
 	mlxsw_sp_acl_erp_region_fini(aregion);
 	aregion->ops->fini(aregion);
 	rhashtable_destroy(&aregion->entries_ht);
+	WARN_ON(!list_empty(&aregion->entries_list));
 }
 
 void mlxsw_sp_acl_atcam_chunk_init(struct mlxsw_sp_acl_atcam_region *aregion,
@@ -499,6 +501,12 @@ __mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 		mlxsw_sp_acl_erp_delta_value(delta, aentry->full_enc_key);
 	mlxsw_sp_acl_erp_delta_clear(delta, aentry->ht_key.enc_key);
 
+	/* Add rule to the list of A-TCAM rules, assuming this
+	 * rule is intended to A-TCAM. In case this rule does
+	 * not fit into A-TCAM it will be removed from the list.
+	 */
+	list_add(&aentry->list, &aregion->entries_list);
+
 	/* We can't insert identical rules into the A-TCAM, so fail and
 	 * let the rule spill into C-TCAM
 	 */
@@ -508,6 +516,13 @@ __mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 	if (err)
 		goto err_rhashtable_insert;
 
+	/* Bloom filter must be updated here, before inserting the rule into
+	 * the A-TCAM.
+	 */
+	err = mlxsw_sp_acl_erp_bf_insert(mlxsw_sp, aregion, erp_mask, aentry);
+	if (err)
+		goto err_bf_insert;
+
 	err = mlxsw_sp_acl_atcam_region_entry_insert(mlxsw_sp, aregion, aentry,
 						     rulei);
 	if (err)
@@ -516,9 +531,12 @@ __mlxsw_sp_acl_atcam_entry_add(struct mlxsw_sp *mlxsw_sp,
 	return 0;
 
 err_rule_insert:
+	mlxsw_sp_acl_erp_bf_remove(mlxsw_sp, aregion, erp_mask, aentry);
+err_bf_insert:
 	rhashtable_remove_fast(&aregion->entries_ht, &aentry->ht_node,
 			       mlxsw_sp_acl_atcam_entries_ht_params);
 err_rhashtable_insert:
+	list_del(&aentry->list);
 	mlxsw_sp_acl_erp_mask_put(aregion, erp_mask);
 	return err;
 }
@@ -529,8 +547,10 @@ __mlxsw_sp_acl_atcam_entry_del(struct mlxsw_sp *mlxsw_sp,
 			       struct mlxsw_sp_acl_atcam_entry *aentry)
 {
 	mlxsw_sp_acl_atcam_region_entry_remove(mlxsw_sp, aregion, aentry);
+	mlxsw_sp_acl_erp_bf_remove(mlxsw_sp, aregion, aentry->erp_mask, aentry);
 	rhashtable_remove_fast(&aregion->entries_ht, &aentry->ht_node,
 			       mlxsw_sp_acl_atcam_entries_ht_params);
+	list_del(&aentry->list);
 	mlxsw_sp_acl_erp_mask_put(aregion, aentry->erp_mask);
 }