ice: Add tracepoint for adding and removing switch rules

Track the number of rules and recipes added to switch. Add a tracepoint to
ice_aq_sw_rules(), which shows both rule and recipe count. This information
can be helpful when designing a set of rules to program to the hardware, as
it shows where the practical limit is. Actual limits are known (64 recipes,
32k rules), but it's hard to translate these values to how many rules the
*user* can actually create, because of extra metadata being implicitly
added, and recipe/rule chaining. Chaining combines several recipes/rules to
create a larger recipe/rule, so one large rule added by the user might
actually consume multiple rules from hardware perspective.

Rule counter is simply incremented/decremented in ice_aq_sw_rules(), since
all rules are added or removed via it.

Counting recipes is harder, as recipes can't be removed (only overwritten).
Recipes added via ice_aq_add_recipe() could end up being unused, when
there is an error in later stages of rule creation. Instead, track the
allocation and freeing of recipes, which should reflect the actual usage of
recipes (if something fails after recipe(s) were created, caller should
free them). Also, a number of recipes are loaded from NVM by default -
initialize the recipe counter with the number of these recipes on switch
initialization.

Example configuration:
  cd /sys/kernel/tracing
  echo function > current_tracer
  echo ice_aq_sw_rules > set_ftrace_filter
  echo ice_aq_sw_rules > set_event
  echo 1 > tracing_on
  cat trace

Example output:
  tc-4097    [069] ...1.   787.595536: ice_aq_sw_rules <-ice_rem_adv_rule
  tc-4097    [069] .....   787.595705: ice_aq_sw_rules: rules=9 recipes=15
  tc-4098    [057] ...1.   787.652033: ice_aq_sw_rules <-ice_add_adv_rule
  tc-4098    [057] .....   787.652201: ice_aq_sw_rules: rules=10 recipes=16

Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_common.c

@@ -934,6 +934,9 @@ static int ice_init_fltr_mgmt_struct(struct ice_hw *hw)
 	INIT_LIST_HEAD(&sw->vsi_list_map_head);
 	sw->prof_res_bm_init = 0;
 
+	/* Initialize recipe count with default recipes read from NVM */
+	sw->recp_cnt = ICE_SW_LKUP_LAST;
+
 	status = ice_init_def_sw_recp(hw);
 	if (status) {
 		devm_kfree(ice_hw_to_dev(hw), hw->switch_info);

drivers/net/ethernet/intel/ice/ice_switch.c

@@ -3,6 +3,7 @@
 
 #include "ice_lib.h"
 #include "ice_switch.h"
+#include "ice_trace.h"
 
 #define ICE_ETH_DA_OFFSET		0
 #define ICE_ETH_ETHTYPE_OFFSET		12
@@ -1961,6 +1962,15 @@ ice_aq_sw_rules(struct ice_hw *hw, void *rule_list, u16 rule_list_sz,
 	    hw->adminq.sq_last_status == ICE_AQ_RC_ENOENT)
 		status = -ENOENT;
 
+	if (!status) {
+		if (opc == ice_aqc_opc_add_sw_rules)
+			hw->switch_info->rule_cnt += num_rules;
+		else if (opc == ice_aqc_opc_remove_sw_rules)
+			hw->switch_info->rule_cnt -= num_rules;
+	}
+
+	trace_ice_aq_sw_rules(hw->switch_info);
+
 	return status;
 }
 
@@ -2181,8 +2191,10 @@ int ice_alloc_recipe(struct ice_hw *hw, u16 *rid)
 	sw_buf->res_type = cpu_to_le16(res_type);
 	status = ice_aq_alloc_free_res(hw, sw_buf, buf_len,
 				       ice_aqc_opc_alloc_res);
-	if (!status)
+	if (!status) {
 		*rid = le16_to_cpu(sw_buf->elem[0].e.sw_resp);
+		hw->switch_info->recp_cnt++;
+	}
 
 	return status;
 }
@@ -2196,7 +2208,13 @@ int ice_alloc_recipe(struct ice_hw *hw, u16 *rid)
  */
 static int ice_free_recipe_res(struct ice_hw *hw, u16 rid)
 {
-	return ice_free_hw_res(hw, ICE_AQC_RES_TYPE_RECIPE, 1, &rid);
+	int status;
+
+	status = ice_free_hw_res(hw, ICE_AQC_RES_TYPE_RECIPE, 1, &rid);
+	if (!status)
+		hw->switch_info->recp_cnt--;
+
+	return status;
 }
 
 /**

drivers/net/ethernet/intel/ice/ice_trace.h

@@ -330,6 +330,24 @@ DEFINE_EVENT(ice_esw_br_port_template,
 	     TP_ARGS(port)
 );
 
+DECLARE_EVENT_CLASS(ice_switch_stats_template,
+		    TP_PROTO(struct ice_switch_info *sw_info),
+		    TP_ARGS(sw_info),
+		    TP_STRUCT__entry(__field(u16, rule_cnt)
+				     __field(u8, recp_cnt)),
+		    TP_fast_assign(__entry->rule_cnt = sw_info->rule_cnt;
+				   __entry->recp_cnt = sw_info->recp_cnt;),
+		    TP_printk("rules=%u recipes=%u",
+			      __entry->rule_cnt,
+			      __entry->recp_cnt)
+);
+
+DEFINE_EVENT(ice_switch_stats_template,
+	     ice_aq_sw_rules,
+	     TP_PROTO(struct ice_switch_info *sw_info),
+	     TP_ARGS(sw_info)
+);
+
 /* End tracepoints */
 
 #endif /* _ICE_TRACE_H_ */

drivers/net/ethernet/intel/ice/ice_type.h

@@ -761,6 +761,8 @@ struct ice_switch_info {
 	struct ice_sw_recipe *recp_list;
 	u16 prof_res_bm_init;
 	u16 max_used_prof_index;
+	u16 rule_cnt;
+	u8 recp_cnt;
 
 	DECLARE_BITMAP(prof_res_bm[ICE_MAX_NUM_PROFILES], ICE_MAX_FV_WORDS);
 };