Merge branch 'PTP-for-DSA-tag_ocelot_8021q'

Vladimir Oltean says:

====================
PTP for DSA tag_ocelot_8021q

Changes in v2:
Add stub definition for ocelot_port_inject_frame when switch driver is
not compiled in.

This is part two of the errata workaround begun here:
https://patchwork.kernel.org/project/netdevbpf/cover/20210129010009.3959398-1-olteanv@gmail.com/

Now that we have basic traffic support when we operate the Ocelot DSA
switches without an NPI port, it would be nice to regain some of the
features lost due to the lack of the NPI port functionality. An
important one is PTP timestamping, which is intimately tied to the DSA
frame header added by the NPI port: on TX, we put a "timestamp request
ID" in the Injection Frame Header, while on RX, the Extraction Frame
Header contains a partial 32-bit PTP timestamp. Get rid of the NPI port
and replace it with a VLAN-based tagger, and you lose PTP, right?

Well, not quite, this is what this patch series is about. The NPI port
is basically a regular Ethernet port configured to service the packets
in and out of the switch's CPU port module (which has other non-DSA I/O
mechanisms too, such as register-based MMIO and DMA). If we disable the
NPI port, we can in theory still access the packets delivered to the CPU
port module by doing exactly what the ocelot switchdev driver does:
extracting Ethernet packets through registers (yes, it is as icky as it
sounds).

However, there's a catch. The Felix switch was integrated into NXP
LS1028A with the idea in mind that it will operate as DSA, i.e. using
the CPU port module connected to the NPI port, not having I/O over
register-based MMIO which is painfully slow and CPU intensive. So
register-based packet I/O not supposed to work - those registers aren't
even documented in the hardware reference manual for Felix. However
they kinda do, with the exception of the fact that an RX interrupt was
really not wired to the CPU cores - so we don't know when the CPU port
module receives a new packet. But we can hack even around that, by
replicating every packet that goes to the CPU port module and making it
also go to a plain internal Ethernet port. Then drop the Ethernet packet
and read the other copy of it from the CPU port module, this time
annotated with the much-wanted RX timestamp.

This is all fine and it works, but it does raise some questions about
what DSA even is anymore, if we start having switches that inject some
of their packets over Ethernet and some through registers, where do we
draw the line. In principle I believe these concerns are founded, but at
the same time, the way that the Felix driver uses register MMIO based
packet I/O is fundamentally the same as any other DSA driver capable of
PTP makes use of a side-channel for timestamps like a FIFO (just that
this one is a lot more complicated, and comes with the entire actual
packet, not just the timestamp).

Nonetheless, I tried to keep the extra pressure added by this ERR
workaround upon the DSA subsystem as small as possible, so some of the
patches are just a revisit of some of Andrew's complaints w.r.t. the
fact that tag_ocelot already violates any driver <-> tagger boundary,
and as a consequence, is not able to be used on testbeds such as
dsa_loop (which it now can). So now, the tag_ocelot and tag_ocelot_8021q
drivers should be dsa_loop-clean, and have the ERR workarounds as
self-contained as possible, using all the designated features for PTP
timestamping and nothing more.

Comments appreciated.
====================

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

13 files changed, 825 insertions, 495 deletions

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index d3180b0f2307..336d93d03a9a 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -14,8 +14,9 @@
 #include <soc/mscc/ocelot_ptp.h>
 #include <soc/mscc/ocelot.h>
 #include <linux/dsa/8021q.h>
+#include <linux/dsa/ocelot.h>
 #include <linux/platform_device.h>
-#include <linux/packing.h>
+#include <linux/ptp_classify.h>
 #include <linux/module.h>
 #include <linux/of_net.h>
 #include <linux/pci.h>
@@ -264,6 +265,129 @@ static void felix_8021q_cpu_port_deinit(struct ocelot *ocelot, int port)
 	ocelot_apply_bridge_fwd_mask(ocelot);
 }
 
+/* Set up a VCAP IS2 rule for delivering PTP frames to the CPU port module.
+ * If the quirk_no_xtr_irq is in place, then also copy those PTP frames to the
+ * tag_8021q CPU port.
+ */
+static int felix_setup_mmio_filtering(struct felix *felix)
+{
+	unsigned long user_ports = 0, cpu_ports = 0;
+	struct ocelot_vcap_filter *redirect_rule;
+	struct ocelot_vcap_filter *tagging_rule;
+	struct ocelot *ocelot = &felix->ocelot;
+	struct dsa_switch *ds = felix->ds;
+	int port, ret;
+
+	tagging_rule = kzalloc(sizeof(struct ocelot_vcap_filter), GFP_KERNEL);
+	if (!tagging_rule)
+		return -ENOMEM;
+
+	redirect_rule = kzalloc(sizeof(struct ocelot_vcap_filter), GFP_KERNEL);
+	if (!redirect_rule) {
+		kfree(tagging_rule);
+		return -ENOMEM;
+	}
+
+	for (port = 0; port < ocelot->num_phys_ports; port++) {
+		if (dsa_is_user_port(ds, port))
+			user_ports |= BIT(port);
+		if (dsa_is_cpu_port(ds, port))
+			cpu_ports |= BIT(port);
+	}
+
+	tagging_rule->key_type = OCELOT_VCAP_KEY_ETYPE;
+	*(__be16 *)tagging_rule->key.etype.etype.value = htons(ETH_P_1588);
+	*(__be16 *)tagging_rule->key.etype.etype.mask = htons(0xffff);
+	tagging_rule->ingress_port_mask = user_ports;
+	tagging_rule->prio = 1;
+	tagging_rule->id.cookie = ocelot->num_phys_ports;
+	tagging_rule->id.tc_offload = false;
+	tagging_rule->block_id = VCAP_IS1;
+	tagging_rule->type = OCELOT_VCAP_FILTER_OFFLOAD;
+	tagging_rule->lookup = 0;
+	tagging_rule->action.pag_override_mask = 0xff;
+	tagging_rule->action.pag_val = ocelot->num_phys_ports;
+
+	ret = ocelot_vcap_filter_add(ocelot, tagging_rule, NULL);
+	if (ret) {
+		kfree(tagging_rule);
+		kfree(redirect_rule);
+		return ret;
+	}
+
+	redirect_rule->key_type = OCELOT_VCAP_KEY_ANY;
+	redirect_rule->ingress_port_mask = user_ports;
+	redirect_rule->pag = ocelot->num_phys_ports;
+	redirect_rule->prio = 1;
+	redirect_rule->id.cookie = ocelot->num_phys_ports;
+	redirect_rule->id.tc_offload = false;
+	redirect_rule->block_id = VCAP_IS2;
+	redirect_rule->type = OCELOT_VCAP_FILTER_OFFLOAD;
+	redirect_rule->lookup = 0;
+	redirect_rule->action.cpu_copy_ena = true;
+	if (felix->info->quirk_no_xtr_irq) {
+		/* Redirect to the tag_8021q CPU but also copy PTP packets to
+		 * the CPU port module
+		 */
+		redirect_rule->action.mask_mode = OCELOT_MASK_MODE_REDIRECT;
+		redirect_rule->action.port_mask = cpu_ports;
+	} else {
+		/* Trap PTP packets only to the CPU port module (which is
+		 * redirected to the NPI port)
+		 */
+		redirect_rule->action.mask_mode = OCELOT_MASK_MODE_PERMIT_DENY;
+		redirect_rule->action.port_mask = 0;
+	}
+
+	ret = ocelot_vcap_filter_add(ocelot, redirect_rule, NULL);
+	if (ret) {
+		ocelot_vcap_filter_del(ocelot, tagging_rule);
+		kfree(redirect_rule);
+		return ret;
+	}
+
+	/* The ownership of the CPU port module's queues might have just been
+	 * transferred to the tag_8021q tagger from the NPI-based tagger.
+	 * So there might still be all sorts of crap in the queues. On the
+	 * other hand, the MMIO-based matching of PTP frames is very brittle,
+	 * so we need to be careful that there are no extra frames to be
+	 * dequeued over MMIO, since we would never know to discard them.
+	 */
+	ocelot_drain_cpu_queue(ocelot, 0);
+
+	return 0;
+}
+
+static int felix_teardown_mmio_filtering(struct felix *felix)
+{
+	struct ocelot_vcap_filter *tagging_rule, *redirect_rule;
+	struct ocelot_vcap_block *block_vcap_is1;
+	struct ocelot_vcap_block *block_vcap_is2;
+	struct ocelot *ocelot = &felix->ocelot;
+	int err;
+
+	block_vcap_is1 = &ocelot->block[VCAP_IS1];
+	block_vcap_is2 = &ocelot->block[VCAP_IS2];
+
+	tagging_rule = ocelot_vcap_block_find_filter_by_id(block_vcap_is1,
+							   ocelot->num_phys_ports,
+							   false);
+	if (!tagging_rule)
+		return -ENOENT;
+
+	err = ocelot_vcap_filter_del(ocelot, tagging_rule);
+	if (err)
+		return err;
+
+	redirect_rule = ocelot_vcap_block_find_filter_by_id(block_vcap_is2,
+							    ocelot->num_phys_ports,
+							    false);
+	if (!redirect_rule)
+		return -ENOENT;
+
+	return ocelot_vcap_filter_del(ocelot, redirect_rule);
+}
+
 static int felix_setup_tag_8021q(struct dsa_switch *ds, int cpu)
 {
 	struct ocelot *ocelot = ds->priv;
@@ -292,9 +416,9 @@ static int felix_setup_tag_8021q(struct dsa_switch *ds, int cpu)
 				 ANA_PORT_CPU_FWD_BPDU_CFG, port);
 	}
 
-	/* In tag_8021q mode, the CPU port module is unused. So we
-	 * want to disable flooding of any kind to the CPU port module,
-	 * since packets going there will end in a black hole.
+	/* In tag_8021q mode, the CPU port module is unused, except for PTP
+	 * frames. So we want to disable flooding of any kind to the CPU port
+	 * module, since packets going there will end in a black hole.
 	 */
 	cpu_flood = ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports));
 	ocelot_rmw_rix(ocelot, 0, cpu_flood, ANA_PGID_PGID, PGID_UC);
@@ -314,8 +438,14 @@ static int felix_setup_tag_8021q(struct dsa_switch *ds, int cpu)
 	if (err)
 		goto out_free_dsa_8021_ctx;
 
+	err = felix_setup_mmio_filtering(felix);
+	if (err)
+		goto out_teardown_dsa_8021q;
+
 	return 0;
 
+out_teardown_dsa_8021q:
+	dsa_8021q_setup(felix->dsa_8021q_ctx, false);
 out_free_dsa_8021_ctx:
 	kfree(felix->dsa_8021q_ctx);
 	return err;
@@ -327,6 +457,11 @@ static void felix_teardown_tag_8021q(struct dsa_switch *ds, int cpu)
 	struct felix *felix = ocelot_to_felix(ocelot);
 	int err, port;
 
+	err = felix_teardown_mmio_filtering(felix);
+	if (err)
+		dev_err(ds->dev, "felix_teardown_mmio_filtering returned %d",
+			err);
+
 	err = dsa_8021q_setup(felix->dsa_8021q_ctx, false);
 	if (err)
 		dev_err(ds->dev, "dsa_8021q_setup returned %d", err);
@@ -431,6 +566,7 @@ static int felix_set_tag_protocol(struct dsa_switch *ds, int cpu,
 	int err;
 
 	switch (proto) {
+	case DSA_TAG_PROTO_SEVILLE:
 	case DSA_TAG_PROTO_OCELOT:
 		err = felix_setup_tag_npi(ds, cpu);
 		break;
@@ -448,6 +584,7 @@ static void felix_del_tag_protocol(struct dsa_switch *ds, int cpu,
 				   enum dsa_tag_protocol proto)
 {
 	switch (proto) {
+	case DSA_TAG_PROTO_SEVILLE:
 	case DSA_TAG_PROTO_OCELOT:
 		felix_teardown_tag_npi(ds, cpu);
 		break;
@@ -471,7 +608,8 @@ static int felix_change_tag_protocol(struct dsa_switch *ds, int cpu,
 	enum dsa_tag_protocol old_proto = felix->tag_proto;
 	int err;
 
-	if (proto != DSA_TAG_PROTO_OCELOT &&
+	if (proto != DSA_TAG_PROTO_SEVILLE &&
+	    proto != DSA_TAG_PROTO_OCELOT &&
 	    proto != DSA_TAG_PROTO_OCELOT_8021Q)
 		return -EPROTONOSUPPORT;
 
@@ -1003,7 +1141,6 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	for (port = 0; port < num_phys_ports; port++) {
 		struct ocelot_port *ocelot_port;
 		struct regmap *target;
-		u8 *template;
 
 		ocelot_port = devm_kzalloc(ocelot->dev,
 					   sizeof(struct ocelot_port),
@@ -1029,22 +1166,10 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 			return PTR_ERR(target);
 		}
 
-		template = devm_kzalloc(ocelot->dev, OCELOT_TOTAL_TAG_LEN,
-					GFP_KERNEL);
-		if (!template) {
-			dev_err(ocelot->dev,
-				"Failed to allocate memory for DSA tag\n");
-			kfree(port_phy_modes);
-			return -ENOMEM;
-		}
-
 		ocelot_port->phy_mode = port_phy_modes[port];
 		ocelot_port->ocelot = ocelot;
 		ocelot_port->target = target;
-		ocelot_port->xmit_template = template;
 		ocelot->ports[port] = ocelot_port;
-
-		felix->info->xmit_template_populate(ocelot, port);
 	}
 
 	kfree(port_phy_modes);
@@ -1158,20 +1283,79 @@ static int felix_hwtstamp_set(struct dsa_switch *ds, int port,
 	return ocelot_hwstamp_set(ocelot, port, ifr);
 }
 
+static bool felix_check_xtr_pkt(struct ocelot *ocelot, unsigned int ptp_type)
+{
+	struct felix *felix = ocelot_to_felix(ocelot);
+	int err, grp = 0;
+
+	if (felix->tag_proto != DSA_TAG_PROTO_OCELOT_8021Q)
+		return false;
+
+	if (!felix->info->quirk_no_xtr_irq)
+		return false;
+
+	if (ptp_type == PTP_CLASS_NONE)
+		return false;
+
+	while (ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp)) {
+		struct sk_buff *skb;
+		unsigned int type;
+
+		err = ocelot_xtr_poll_frame(ocelot, grp, &skb);
+		if (err)
+			goto out;
+
+		/* We trap to the CPU port module all PTP frames, but
+		 * felix_rxtstamp() only gets called for event frames.
+		 * So we need to avoid sending duplicate general
+		 * message frames by running a second BPF classifier
+		 * here and dropping those.
+		 */
+		__skb_push(skb, ETH_HLEN);
+
+		type = ptp_classify_raw(skb);
+
+		__skb_pull(skb, ETH_HLEN);
+
+		if (type == PTP_CLASS_NONE) {
+			kfree_skb(skb);
+			continue;
+		}
+
+		netif_rx(skb);
+	}
+
+out:
+	if (err < 0)
+		ocelot_drain_cpu_queue(ocelot, 0);
+
+	return true;
+}
+
 static bool felix_rxtstamp(struct dsa_switch *ds, int port,
 			   struct sk_buff *skb, unsigned int type)
 {
+	u8 *extraction = skb->data - ETH_HLEN - OCELOT_TAG_LEN;
 	struct skb_shared_hwtstamps *shhwtstamps;
 	struct ocelot *ocelot = ds->priv;
-	u8 *extraction = skb->data - ETH_HLEN - OCELOT_TAG_LEN;
 	u32 tstamp_lo, tstamp_hi;
 	struct timespec64 ts;
 	u64 tstamp, val;
 
+	/* If the "no XTR IRQ" workaround is in use, tell DSA to defer this skb
+	 * for RX timestamping. Then free it, and poll for its copy through
+	 * MMIO in the CPU port module, and inject that into the stack from
+	 * ocelot_xtr_poll().
+	 */
+	if (felix_check_xtr_pkt(ocelot, type)) {
+		kfree_skb(skb);
+		return true;
+	}
+
 	ocelot_ptp_gettime64(&ocelot->ptp_info, &ts);
 	tstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
 
-	packing(extraction, &val,  116, 85, OCELOT_TAG_LEN, UNPACK, 0);
+	ocelot_xfh_get_rew_val(extraction, &val);
 	tstamp_lo = (u32)val;
 
 	tstamp_hi = tstamp >> 32;
diff --git a/drivers/net/dsa/ocelot/felix.h b/drivers/net/dsa/ocelot/felix.h
index 9d4459f2fffb..4d96cad815d5 100644
--- a/drivers/net/dsa/ocelot/felix.h
+++ b/drivers/net/dsa/ocelot/felix.h
@@ -23,6 +23,19 @@ struct felix_info {
 	int				switch_pci_bar;
 	int				imdio_pci_bar;
 	const struct ptp_clock_info	*ptp_caps;
+
+	/* Some Ocelot switches are integrated into the SoC without the
+	 * extraction IRQ line connected to the ARM GIC. By enabling this
+	 * workaround, the few packets that are delivered to the CPU port
+	 * module (currently only PTP) are copied not only to the hardware CPU
+	 * port module, but also to the 802.1Q Ethernet CPU port, and polling
+	 * the extraction registers is triggered once the DSA tagger sees a PTP
+	 * frame. The Ethernet frame is only used as a notification: it is
+	 * dropped, and the original frame is extracted over MMIO and annotated
+	 * with the RX timestamp.
+	 */
+	bool				quirk_no_xtr_irq;
+
 	int	(*mdio_bus_alloc)(struct ocelot *ocelot);
 	void	(*mdio_bus_free)(struct ocelot *ocelot);
 	void	(*phylink_validate)(struct ocelot *ocelot, int port,
@@ -34,7 +47,6 @@ struct felix_info {
 				 enum tc_setup_type type, void *type_data);
 	void	(*port_sched_speed_set)(struct ocelot *ocelot, int port,
 					u32 speed);
-	void	(*xmit_template_populate)(struct ocelot *ocelot, int port);
 };
 
 extern const struct dsa_switch_ops felix_switch_ops;
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index e944868cc120..5ff623ee76a6 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -8,7 +8,7 @@
 #include <soc/mscc/ocelot_ptp.h>
 #include <soc/mscc/ocelot_sys.h>
 #include <soc/mscc/ocelot.h>
-#include <linux/packing.h>
+#include <linux/dsa/ocelot.h>
 #include <linux/pcs-lynx.h>
 #include <net/pkt_sched.h>
 #include <linux/iopoll.h>
@@ -1339,31 +1339,6 @@ static int vsc9959_port_setup_tc(struct dsa_switch *ds, int port,
 	}
 }
 
-static void vsc9959_xmit_template_populate(struct ocelot *ocelot, int port)
-{
-	struct ocelot_port *ocelot_port = ocelot->ports[port];
-	u8 *template = ocelot_port->xmit_template;
-	u64 bypass, dest, src;
-	__be32 *prefix;
-	u8 *injection;
-
-	/* Set the source port as the CPU port module and not the
-	 * NPI port
-	 */
-	src = ocelot->num_phys_ports;
-	dest = BIT(port);
-	bypass = true;
-
-	injection = template + OCELOT_SHORT_PREFIX_LEN;
-	prefix = (__be32 *)template;
-
-	packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0);
-	packing(injection, &dest,    68,  56, OCELOT_TAG_LEN, PACK, 0);
-	packing(injection, &src,     46,  43, OCELOT_TAG_LEN, PACK, 0);
-
-	*prefix = cpu_to_be32(0x8880000a);
-}
-
 static const struct felix_info felix_info_vsc9959 = {
 	.target_io_res		= vsc9959_target_io_res,
 	.port_io_res		= vsc9959_port_io_res,
@@ -1379,6 +1354,7 @@ static const struct felix_info felix_info_vsc9959 = {
 	.num_tx_queues		= OCELOT_NUM_TC,
 	.switch_pci_bar		= 4,
 	.imdio_pci_bar		= 0,
+	.quirk_no_xtr_irq	= true,
 	.ptp_caps		= &vsc9959_ptp_caps,
 	.mdio_bus_alloc		= vsc9959_mdio_bus_alloc,
 	.mdio_bus_free		= vsc9959_mdio_bus_free,
@@ -1386,7 +1362,6 @@ static const struct felix_info felix_info_vsc9959 = {
 	.prevalidate_phy_mode	= vsc9959_prevalidate_phy_mode,
 	.port_setup_tc		= vsc9959_port_setup_tc,
 	.port_sched_speed_set	= vsc9959_sched_speed_set,
-	.xmit_template_populate	= vsc9959_xmit_template_populate,
 };
 
 static irqreturn_t felix_irq_handler(int irq, void *data)
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index 512f677a6c1c..84f93a874d50 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -8,7 +8,7 @@
 #include <soc/mscc/ocelot.h>
 #include <linux/of_platform.h>
 #include <linux/pcs-lynx.h>
-#include <linux/packing.h>
+#include <linux/dsa/ocelot.h>
 #include <linux/iopoll.h>
 #include "felix.h"
 
@@ -1165,31 +1165,6 @@ static void vsc9953_mdio_bus_free(struct ocelot *ocelot)
 	mdiobus_unregister(felix->imdio);
 }
 
-static void vsc9953_xmit_template_populate(struct ocelot *ocelot, int port)
-{
-	struct ocelot_port *ocelot_port = ocelot->ports[port];
-	u8 *template = ocelot_port->xmit_template;
-	u64 bypass, dest, src;
-	__be32 *prefix;
-	u8 *injection;
-
-	/* Set the source port as the CPU port module and not the
-	 * NPI port
-	 */
-	src = ocelot->num_phys_ports;
-	dest = BIT(port);
-	bypass = true;
-
-	injection = template + OCELOT_SHORT_PREFIX_LEN;
-	prefix = (__be32 *)template;
-
-	packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0);
-	packing(injection, &dest,    67,  57, OCELOT_TAG_LEN, PACK, 0);
-	packing(injection, &src,     46,  43, OCELOT_TAG_LEN, PACK, 0);
-
-	*prefix = cpu_to_be32(0x88800005);
-}
-
 static const struct felix_info seville_info_vsc9953 = {
 	.target_io_res		= vsc9953_target_io_res,
 	.port_io_res		= vsc9953_port_io_res,
@@ -1206,7 +1181,6 @@ static const struct felix_info seville_info_vsc9953 = {
 	.mdio_bus_free		= vsc9953_mdio_bus_free,
 	.phylink_validate	= vsc9953_phylink_validate,
 	.prevalidate_phy_mode	= vsc9953_prevalidate_phy_mode,
-	.xmit_template_populate	= vsc9953_xmit_template_populate,
 };
 
 static int seville_probe(struct platform_device *pdev)
@@ -1246,7 +1220,7 @@ static int seville_probe(struct platform_device *pdev)
 	ds->ops = &felix_switch_ops;
 	ds->priv = ocelot;
 	felix->ds = ds;
-	felix->tag_proto = DSA_TAG_PROTO_OCELOT;
+	felix->tag_proto = DSA_TAG_PROTO_SEVILLE;
 
 	err = dsa_register_switch(ds);
 	if (err) {
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index d1a9cdbf7a3e..8d97c731e953 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -4,6 +4,7 @@
  *
  * Copyright (c) 2017 Microsemi Corporation
  */
+#include <linux/dsa/ocelot.h>
 #include <linux/if_bridge.h>
 #include <soc/mscc/ocelot_vcap.h>
 #include "ocelot.h"
@@ -628,6 +629,221 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 }
 EXPORT_SYMBOL(ocelot_get_txtstamp);
 
+static int ocelot_rx_frame_word(struct ocelot *ocelot, u8 grp, bool ifh,
+				u32 *rval)
+{
+	u32 bytes_valid, val;
+
+	val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+	if (val == XTR_NOT_READY) {
+		if (ifh)
+			return -EIO;
+
+		do {
+			val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		} while (val == XTR_NOT_READY);
+	}
+
+	switch (val) {
+	case XTR_ABORT:
+		return -EIO;
+	case XTR_EOF_0:
+	case XTR_EOF_1:
+	case XTR_EOF_2:
+	case XTR_EOF_3:
+	case XTR_PRUNED:
+		bytes_valid = XTR_VALID_BYTES(val);
+		val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		if (val == XTR_ESCAPE)
+			*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		else
+			*rval = val;
+
+		return bytes_valid;
+	case XTR_ESCAPE:
+		*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+
+		return 4;
+	default:
+		*rval = val;
+
+		return 4;
+	}
+}
+
+static int ocelot_xtr_poll_xfh(struct ocelot *ocelot, int grp, u32 *xfh)
+{
+	int i, err = 0;
+
+	for (i = 0; i < OCELOT_TAG_LEN / 4; i++) {
+		err = ocelot_rx_frame_word(ocelot, grp, true, &xfh[i]);
+		if (err != 4)
+			return (err < 0) ? err : -EIO;
+	}
+
+	return 0;
+}
+
+int ocelot_xtr_poll_frame(struct ocelot *ocelot, int grp, struct sk_buff **nskb)
+{
+	struct skb_shared_hwtstamps *shhwtstamps;
+	u64 tod_in_ns, full_ts_in_ns;
+	u64 timestamp, src_port, len;
+	u32 xfh[OCELOT_TAG_LEN / 4];
+	struct net_device *dev;
+	struct timespec64 ts;
+	struct sk_buff *skb;
+	int sz, buf_len;
+	u32 val, *buf;
+	int err;
+
+	err = ocelot_xtr_poll_xfh(ocelot, grp, xfh);
+	if (err)
+		return err;
+
+	ocelot_xfh_get_src_port(xfh, &src_port);
+	ocelot_xfh_get_len(xfh, &len);
+	ocelot_xfh_get_rew_val(xfh, &timestamp);
+
+	if (WARN_ON(src_port >= ocelot->num_phys_ports))
+		return -EINVAL;
+
+	dev = ocelot->ops->port_to_netdev(ocelot, src_port);
+	if (!dev)
+		return -EINVAL;
+
+	skb = netdev_alloc_skb(dev, len);
+	if (unlikely(!skb)) {
+		netdev_err(dev, "Unable to allocate sk_buff\n");
+		return -ENOMEM;
+	}
+
+	buf_len = len - ETH_FCS_LEN;
+	buf = (u32 *)skb_put(skb, buf_len);
+
+	len = 0;
+	do {
+		sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
+		if (sz < 0) {
+			err = sz;
+			goto out_free_skb;
+		}
+		*buf++ = val;
+		len += sz;
+	} while (len < buf_len);
+
+	/* Read the FCS */
+	sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
+	if (sz < 0) {
+		err = sz;
+		goto out_free_skb;
+	}
+
+	/* Update the statistics if part of the FCS was read before */
+	len -= ETH_FCS_LEN - sz;
+
+	if (unlikely(dev->features & NETIF_F_RXFCS)) {
+		buf = (u32 *)skb_put(skb, ETH_FCS_LEN);
+		*buf = val;
+	}
+
+	if (ocelot->ptp) {
+		ocelot_ptp_gettime64(&ocelot->ptp_info, &ts);
+
+		tod_in_ns = ktime_set(ts.tv_sec, ts.tv_nsec);
+		if ((tod_in_ns & 0xffffffff) < timestamp)
+			full_ts_in_ns = (((tod_in_ns >> 32) - 1) << 32) |
+					timestamp;
+		else
+			full_ts_in_ns = (tod_in_ns & GENMASK_ULL(63, 32)) |
+					timestamp;
+
+		shhwtstamps = skb_hwtstamps(skb);
+		memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
+		shhwtstamps->hwtstamp = full_ts_in_ns;
+	}
+
+	/* Everything we see on an interface that is in the HW bridge
+	 * has already been forwarded.
+	 */
+	if (ocelot->bridge_mask & BIT(src_port))
+		skb->offload_fwd_mark = 1;
+
+	skb->protocol = eth_type_trans(skb, dev);
+	*nskb = skb;
+
+	return 0;
+
+out_free_skb:
+	kfree_skb(skb);
+	return err;
+}
+EXPORT_SYMBOL(ocelot_xtr_poll_frame);
+
+bool ocelot_can_inject(struct ocelot *ocelot, int grp)
+{
+	u32 val = ocelot_read(ocelot, QS_INJ_STATUS);
+
+	if (!(val & QS_INJ_STATUS_FIFO_RDY(BIT(grp))))
+		return false;
+	if (val & QS_INJ_STATUS_WMARK_REACHED(BIT(grp)))
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL(ocelot_can_inject);
+
+void ocelot_port_inject_frame(struct ocelot *ocelot, int port, int grp,
+			      u32 rew_op, struct sk_buff *skb)
+{
+	u32 ifh[OCELOT_TAG_LEN / 4] = {0};
+	unsigned int i, count, last;
+
+	ocelot_write_rix(ocelot, QS_INJ_CTRL_GAP_SIZE(1) |
+			 QS_INJ_CTRL_SOF, QS_INJ_CTRL, grp);
+
+	ocelot_ifh_set_bypass(ifh, 1);
+	ocelot_ifh_set_dest(ifh, BIT(port));
+	ocelot_ifh_set_tag_type(ifh, IFH_TAG_TYPE_C);
+	ocelot_ifh_set_vid(ifh, skb_vlan_tag_get(skb));
+	ocelot_ifh_set_rew_op(ifh, rew_op);
+
+	for (i = 0; i < OCELOT_TAG_LEN / 4; i++)
+		ocelot_write_rix(ocelot, ifh[i], QS_INJ_WR, grp);
+
+	count = DIV_ROUND_UP(skb->len, 4);
+	last = skb->len % 4;
+	for (i = 0; i < count; i++)
+		ocelot_write_rix(ocelot, ((u32 *)skb->data)[i], QS_INJ_WR, grp);
+
+	/* Add padding */
+	while (i < (OCELOT_BUFFER_CELL_SZ / 4)) {
+		ocelot_write_rix(ocelot, 0, QS_INJ_WR, grp);
+		i++;
+	}
+
+	/* Indicate EOF and valid bytes in last word */
+	ocelot_write_rix(ocelot, QS_INJ_CTRL_GAP_SIZE(1) |
+			 QS_INJ_CTRL_VLD_BYTES(skb->len < OCELOT_BUFFER_CELL_SZ ? 0 : last) |
+			 QS_INJ_CTRL_EOF,
+			 QS_INJ_CTRL, grp);
+
+	/* Add dummy CRC */
+	ocelot_write_rix(ocelot, 0, QS_INJ_WR, grp);
+	skb_tx_timestamp(skb);
+
+	skb->dev->stats.tx_packets++;
+	skb->dev->stats.tx_bytes += skb->len;
+}
+EXPORT_SYMBOL(ocelot_port_inject_frame);
+
+void ocelot_drain_cpu_queue(struct ocelot *ocelot, int grp)
+{
+	while (ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp))
+		ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+}
+EXPORT_SYMBOL(ocelot_drain_cpu_queue);
+
 int ocelot_fdb_add(struct ocelot *ocelot, int port,
 		   const unsigned char *addr, u16 vid)
 {
diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h
index c485795c606b..db6b1a4c3926 100644
--- a/drivers/net/ethernet/mscc/ocelot.h
+++ b/drivers/net/ethernet/mscc/ocelot.h
@@ -32,15 +32,6 @@
 
 #define OCELOT_PTP_QUEUE_SZ	128
 
-struct frame_info {
-	u32 len;
-	u16 port;
-	u16 vid;
-	u8 tag_type;
-	u16 rew_op;
-	u32 timestamp;	/* rew_val */
-};
-
 struct ocelot_port_tc {
 	bool block_shared;
 	unsigned long offload_cnt;
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index b5ffe6724eb7..6518262532f0 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -488,53 +488,20 @@ static int ocelot_port_stop(struct net_device *dev)
 	return 0;
 }
 
-/* Generate the IFH for frame injection
- *
- * The IFH is a 128bit-value
- * bit 127: bypass the analyzer processing
- * bit 56-67: destination mask
- * bit 28-29: pop_cnt: 3 disables all rewriting of the frame
- * bit 20-27: cpu extraction queue mask
- * bit 16: tag type 0: C-tag, 1: S-tag
- * bit 0-11: VID
- */
-static int ocelot_gen_ifh(u32 *ifh, struct frame_info *info)
-{
-	ifh[0] = IFH_INJ_BYPASS | ((0x1ff & info->rew_op) << 21);
-	ifh[1] = (0xf00 & info->port) >> 8;
-	ifh[2] = (0xff & info->port) << 24;
-	ifh[3] = (info->tag_type << 16) | info->vid;
-
-	return 0;
-}
-
-static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ocelot_port_private *priv = netdev_priv(dev);
-	struct skb_shared_info *shinfo = skb_shinfo(skb);
 	struct ocelot_port *ocelot_port = &priv->port;
 	struct ocelot *ocelot = ocelot_port->ocelot;
-	u32 val, ifh[OCELOT_TAG_LEN / 4];
-	struct frame_info info = {};
-	u8 grp = 0; /* Send everything on CPU group 0 */
-	unsigned int i, count, last;
 	int port = priv->chip_port;
+	u32 rew_op = 0;
 
-	val = ocelot_read(ocelot, QS_INJ_STATUS);
-	if (!(val & QS_INJ_STATUS_FIFO_RDY(BIT(grp))) ||
-	    (val & QS_INJ_STATUS_WMARK_REACHED(BIT(grp))))
+	if (!ocelot_can_inject(ocelot, 0))
 		return NETDEV_TX_BUSY;
 
-	ocelot_write_rix(ocelot, QS_INJ_CTRL_GAP_SIZE(1) |
-			 QS_INJ_CTRL_SOF, QS_INJ_CTRL, grp);
-
-	info.port = BIT(port);
-	info.tag_type = IFH_TAG_TYPE_C;
-	info.vid = skb_vlan_tag_get(skb);
-
 	/* Check if timestamping is needed */
-	if (ocelot->ptp && (shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
-		info.rew_op = ocelot_port->ptp_cmd;
+	if (ocelot->ptp && (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
+		rew_op = ocelot_port->ptp_cmd;
 
 		if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
 			struct sk_buff *clone;
@@ -547,45 +514,11 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
 
 			ocelot_port_add_txtstamp_skb(ocelot, port, clone);
 
-			info.rew_op |= clone->cb[0] << 3;
+			rew_op |= clone->cb[0] << 3;
 		}
 	}
 
-	if (ocelot->ptp && shinfo->tx_flags & SKBTX_HW_TSTAMP) {
-		info.rew_op = ocelot_port->ptp_cmd;
-		if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
-			info.rew_op |= skb->cb[0] << 3;
-	}
-
-	ocelot_gen_ifh(ifh, &info);
-
-	for (i = 0; i < OCELOT_TAG_LEN / 4; i++)
-		ocelot_write_rix(ocelot, (__force u32)cpu_to_be32(ifh[i]),
-				 QS_INJ_WR, grp);
-
-	count = (skb->len + 3) / 4;
-	last = skb->len % 4;
-	for (i = 0; i < count; i++)
-		ocelot_write_rix(ocelot, ((u32 *)skb->data)[i], QS_INJ_WR, grp);
-
-	/* Add padding */
-	while (i < (OCELOT_BUFFER_CELL_SZ / 4)) {
-		ocelot_write_rix(ocelot, 0, QS_INJ_WR, grp);
-		i++;
-	}
-
-	/* Indicate EOF and valid bytes in last word */
-	ocelot_write_rix(ocelot, QS_INJ_CTRL_GAP_SIZE(1) |
-			 QS_INJ_CTRL_VLD_BYTES(skb->len < OCELOT_BUFFER_CELL_SZ ? 0 : last) |
-			 QS_INJ_CTRL_EOF,
-			 QS_INJ_CTRL, grp);
-
-	/* Add dummy CRC */
-	ocelot_write_rix(ocelot, 0, QS_INJ_WR, grp);
-	skb_tx_timestamp(skb);
-
-	dev->stats.tx_packets++;
-	dev->stats.tx_bytes += skb->len;
+	ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);
 
 	kfree_skb(skb);
 
diff --git a/drivers/net/ethernet/mscc/ocelot_vsc7514.c b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
index 6b6eb92149ba..4bd7e9d9ec61 100644
--- a/drivers/net/ethernet/mscc/ocelot_vsc7514.c
+++ b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
@@ -4,6 +4,7 @@
  *
  * Copyright (c) 2017 Microsemi Corporation
  */
+#include <linux/dsa/ocelot.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of_net.h>
@@ -18,8 +19,6 @@
 #include <soc/mscc/ocelot_hsio.h>
 #include "ocelot.h"
 
-#define IFH_EXTRACT_BITFIELD64(x, o, w) (((x) >> (o)) & GENMASK_ULL((w) - 1, 0))
-
 static const u32 ocelot_ana_regmap[] = {
 	REG(ANA_ADVLEARN,				0x009000),
 	REG(ANA_VLANMASK,				0x009004),
@@ -532,181 +531,28 @@ static int ocelot_chip_init(struct ocelot *ocelot, const struct ocelot_ops *ops)
 	return 0;
 }
 
-static int ocelot_parse_ifh(u32 *_ifh, struct frame_info *info)
-{
-	u8 llen, wlen;
-	u64 ifh[2];
-
-	ifh[0] = be64_to_cpu(((__force __be64 *)_ifh)[0]);
-	ifh[1] = be64_to_cpu(((__force __be64 *)_ifh)[1]);
-
-	wlen = IFH_EXTRACT_BITFIELD64(ifh[0], 7,  8);
-	llen = IFH_EXTRACT_BITFIELD64(ifh[0], 15,  6);
-
-	info->len = OCELOT_BUFFER_CELL_SZ * wlen + llen - 80;
-
-	info->timestamp = IFH_EXTRACT_BITFIELD64(ifh[0], 21, 32);
-
-	info->port = IFH_EXTRACT_BITFIELD64(ifh[1], 43, 4);
-
-	info->tag_type = IFH_EXTRACT_BITFIELD64(ifh[1], 16,  1);
-	info->vid = IFH_EXTRACT_BITFIELD64(ifh[1], 0,  12);
-
-	return 0;
-}
-
-static int ocelot_rx_frame_word(struct ocelot *ocelot, u8 grp, bool ifh,
-				u32 *rval)
-{
-	u32 val;
-	u32 bytes_valid;
-
-	val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
-	if (val == XTR_NOT_READY) {
-		if (ifh)