net: microchip: sparx5: add support for PSFP flow-meters

Add support for configuring PSFP flow-meters (IEEE 802.1Q-2018,
8.6.5.1.3).

The VCAP CLM (VCAP IS0 ingress classifier) classifies streams,
identified by ISDX (Ingress Service Index, frame metadata), and maps
ISDX to flow-meters. SDLB's provide the flow-meter parameters.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/Makefile

@@ -10,7 +10,7 @@ sparx5-switch-y  := sparx5_main.o sparx5_packet.o \
  sparx5_switchdev.o sparx5_calendar.o sparx5_ethtool.o sparx5_fdma.o \
  sparx5_ptp.o sparx5_pgid.o sparx5_tc.o sparx5_qos.o \
  sparx5_vcap_impl.o sparx5_vcap_ag_api.o sparx5_tc_flower.o \
- sparx5_tc_matchall.o sparx5_pool.o sparx5_sdlb.o sparx5_police.o
+ sparx5_tc_matchall.o sparx5_pool.o sparx5_sdlb.o sparx5_police.o sparx5_psfp.o
 
 sparx5-switch-$(CONFIG_SPARX5_DCB) += sparx5_dcb.o
 sparx5-switch-$(CONFIG_DEBUG_FS) += sparx5_vcap_debugfs.o

drivers/net/ethernet/microchip/sparx5/sparx5_main.h

@@ -472,6 +472,15 @@ struct sparx5_policer {
 
 int sparx5_policer_conf_set(struct sparx5 *sparx5, struct sparx5_policer *pol);
 
+/* sparx5_psfp.c */
+struct sparx5_psfp_fm {
+	struct sparx5_policer pol;
+};
+
+int sparx5_psfp_fm_add(struct sparx5 *sparx5, u32 uidx,
+		       struct sparx5_psfp_fm *fm, u32 *id);
+int sparx5_psfp_fm_del(struct sparx5 *sparx5, u32 id);
+
 /* Clock period in picoseconds */
 static inline u32 sparx5_clk_period(enum sparx5_core_clockfreq cclock)
 {

drivers/net/ethernet/microchip/sparx5/sparx5_psfp.c

@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Microchip Sparx5 Switch driver
+ *
+ * Copyright (c) 2023 Microchip Technology Inc. and its subsidiaries.
+ */
+
+#include "sparx5_main_regs.h"
+#include "sparx5_main.h"
+
+/* Pool of available service policers */
+static struct sparx5_pool_entry sparx5_psfp_fm_pool[SPX5_SDLB_CNT];
+
+static int sparx5_psfp_fm_get(u32 idx, u32 *id)
+{
+	return sparx5_pool_get_with_idx(sparx5_psfp_fm_pool, SPX5_SDLB_CNT, idx,
+					id);
+}
+
+static int sparx5_psfp_fm_put(u32 id)
+{
+	return sparx5_pool_put(sparx5_psfp_fm_pool, SPX5_SDLB_CNT, id);
+}
+
+static int sparx5_sdlb_conf_set(struct sparx5 *sparx5,
+				struct sparx5_psfp_fm *fm)
+{
+	int (*sparx5_sdlb_group_action)(struct sparx5 *sparx5, u32 group,
+					u32 idx);
+
+	if (!fm->pol.rate && !fm->pol.burst)
+		sparx5_sdlb_group_action = &sparx5_sdlb_group_del;
+	else
+		sparx5_sdlb_group_action = &sparx5_sdlb_group_add;
+
+	sparx5_policer_conf_set(sparx5, &fm->pol);
+
+	return sparx5_sdlb_group_action(sparx5, fm->pol.group, fm->pol.idx);
+}
+
+int sparx5_psfp_fm_add(struct sparx5 *sparx5, u32 uidx,
+		       struct sparx5_psfp_fm *fm, u32 *id)
+{
+	struct sparx5_policer *pol = &fm->pol;
+	int ret;
+
+	/* Get flow meter */
+	ret = sparx5_psfp_fm_get(uidx, &fm->pol.idx);
+	if (ret < 0)
+		return ret;
+	/* Was already in use, no need to reconfigure */
+	if (ret > 1)
+		return 0;
+
+	ret = sparx5_sdlb_group_get_by_rate(sparx5, pol->rate, pol->burst);
+	if (ret < 0)
+		return ret;
+
+	fm->pol.group = ret;
+
+	ret = sparx5_sdlb_conf_set(sparx5, fm);
+	if (ret < 0)
+		return ret;
+
+	*id = fm->pol.idx;
+
+	return 0;
+}
+
+int sparx5_psfp_fm_del(struct sparx5 *sparx5, u32 id)
+{
+	struct sparx5_psfp_fm fm = { .pol.idx = id,
+				     .pol.type = SPX5_POL_SERVICE };
+	int ret;
+
+	/* Find the group that this lb belongs to */
+	ret = sparx5_sdlb_group_get_by_index(sparx5, id, &fm.pol.group);
+	if (ret < 0)
+		return ret;
+
+	ret = sparx5_psfp_fm_put(id);
+	if (ret < 0)
+		return ret;
+	/* Do not reset flow-meter if still in use. */
+	if (ret > 0)
+		return 0;
+
+	return sparx5_sdlb_conf_set(sparx5, &fm);
+}