net: stmmac: Add support for U32 TC filter using Flexible RX Parser

This adds support for U32 filter by using an HW only feature called
Flexible RX Parser. This allow us to match any given packet field with a
pattern and accept/reject or even route the packet to a specific DMA
channel.

Right now we only support acception or rejection of frame and we only
support simple rules. Though, the Parser has the flexibility of jumping to
specific rules as an if condition so complex rules can be established.

This is only supported in GMAC5.10+.

The following commands can be used to test this code:

	1) Setup an ingress qdisk:
	# tc qdisc add dev eth0 handle ffff: ingress

	2) Setup a filter (e.g. filter by IP):
	# tc filter add dev eth0 parent ffff: protocol ip u32 match ip \
		src 192.168.0.3 skip_sw action drop

In every tests performed we always used the "skip_sw" flag to make sure
only the RX Parser was involved.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 295 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
new file mode 100644
index 000000000000..881c94b73e2f
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
+ * stmmac TC Handling (HW only)
+ */
+
+#include <net/pkt_cls.h>
+#include <net/tc_act/tc_gact.h>
+#include "common.h"
+#include "dwmac4.h"
+#include "dwmac5.h"
+#include "stmmac.h"
+
+static void tc_fill_all_pass_entry(struct stmmac_tc_entry *entry)
+{
+	memset(entry, 0, sizeof(*entry));
+	entry->in_use = true;
+	entry->is_last = true;
+	entry->is_frag = false;
+	entry->prio = ~0x0;
+	entry->handle = 0;
+	entry->val.match_data = 0x0;
+	entry->val.match_en = 0x0;
+	entry->val.af = 1;
+	entry->val.dma_ch_no = 0x0;
+}
+
+static struct stmmac_tc_entry *tc_find_entry(struct stmmac_priv *priv,
+					     struct tc_cls_u32_offload *cls,
+					     bool free)
+{
+	struct stmmac_tc_entry *entry, *first = NULL, *dup = NULL;
+	u32 loc = cls->knode.handle;
+	int i;
+
+	for (i = 0; i < priv->tc_entries_max; i++) {
+		entry = &priv->tc_entries[i];
+		if (!entry->in_use && !first && free)
+			first = entry;
+		if (entry->handle == loc && !free)
+			dup = entry;
+	}
+
+	if (dup)
+		return dup;
+	if (first) {
+		first->handle = loc;
+		first->in_use = true;
+
+		/* Reset HW values */
+		memset(&first->val, 0, sizeof(first->val));
+	}
+
+	return first;
+}
+
+static int tc_fill_actions(struct stmmac_tc_entry *entry,
+			   struct stmmac_tc_entry *frag,
+			   struct tc_cls_u32_offload *cls)
+{
+	struct stmmac_tc_entry *action_entry = entry;
+	const struct tc_action *act;
+	struct tcf_exts *exts;
+	LIST_HEAD(actions);
+
+	exts = cls->knode.exts;
+	if (!tcf_exts_has_actions(exts))
+		return -EINVAL;
+	if (frag)
+		action_entry = frag;
+
+	tcf_exts_to_list(exts, &actions);
+	list_for_each_entry(act, &actions, list) {
+		/* Accept */
+		if (is_tcf_gact_ok(act)) {
+			action_entry->val.af = 1;
+			break;
+		}
+		/* Drop */
+		if (is_tcf_gact_shot(act)) {
+			action_entry->val.rf = 1;
+			break;
+		}
+
+		/* Unsupported */
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tc_fill_entry(struct stmmac_priv *priv,
+			 struct tc_cls_u32_offload *cls)
+{
+	struct stmmac_tc_entry *entry, *frag = NULL;
+	struct tc_u32_sel *sel = cls->knode.sel;
+	u32 off, data, mask, real_off, rem;
+	u32 prio = cls->common.prio;
+	int ret;
+
+	/* Only 1 match per entry */
+	if (sel->nkeys <= 0 || sel->nkeys > 1)
+		return -EINVAL;
+
+	off = sel->keys[0].off << sel->offshift;
+	data = sel->keys[0].val;
+	mask = sel->keys[0].mask;
+
+	switch (ntohs(cls->common.protocol)) {
+	case ETH_P_ALL:
+		break;
+	case ETH_P_IP:
+		off += ETH_HLEN;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (off > priv->tc_off_max)
+		return -EINVAL;
+
+	real_off = off / 4;
+	rem = off % 4;
+
+	entry = tc_find_entry(priv, cls, true);
+	if (!entry)
+		return -EINVAL;
+
+	if (rem) {
+		frag = tc_find_entry(priv, cls, true);
+		if (!frag) {
+			ret = -EINVAL;
+			goto err_unuse;
+		}
+
+		entry->frag_ptr = frag;
+		entry->val.match_en = (mask << (rem * 8)) &
+			GENMASK(31, rem * 8);
+		entry->val.match_data = (data << (rem * 8)) &
+			GENMASK(31, rem * 8);
+		entry->val.frame_offset = real_off;
+		entry->prio = prio;
+
+		frag->val.match_en = (mask >> (rem * 8)) &
+			GENMASK(rem * 8 - 1, 0);
+		frag->val.match_data = (data >> (rem * 8)) &
+			GENMASK(rem * 8 - 1, 0);
+		frag->val.frame_offset = real_off + 1;
+		frag->prio = prio;
+		frag->is_frag = true;
+	} else {
+		entry->frag_ptr = NULL;
+		entry->val.match_en = mask;
+		entry->val.match_data = data;
+		entry->val.frame_offset = real_off;
+		entry->prio = prio;
+	}
+
+	ret = tc_fill_actions(entry, frag, cls);
+	if (ret)
+		goto err_unuse;
+
+	return 0;
+
+err_unuse:
+	if (frag)
+		frag->in_use = false;
+	entry->in_use = false;
+	return ret;
+}
+
+static void tc_unfill_entry(struct stmmac_priv *priv,
+			    struct tc_cls_u32_offload *cls)
+{
+	struct stmmac_tc_entry *entry;
+
+	entry = tc_find_entry(priv, cls, false);
+	if (!entry)
+		return;
+
+	entry->in_use = false;
+	if (entry->frag_ptr) {
+		entry = entry->frag_ptr;
+		entry->is_frag = false;
+		entry->in_use = false;
+	}
+}
+
+static int tc_config_knode(struct stmmac_priv *priv,
+			   struct tc_cls_u32_offload *cls)
+{
+	int ret;
+
+	ret = tc_fill_entry(priv, cls);
+	if (ret)
+		return ret;
+
+	ret = stmmac_rxp_config(priv, priv->hw->pcsr, priv->tc_entries,
+			priv->tc_entries_max);
+	if (ret)
+		goto err_unfill;
+
+	return 0;
+
+err_unfill:
+	tc_unfill_entry(priv, cls);
+	return ret;
+}
+
+static int tc_delete_knode(struct stmmac_priv *priv,
+			   struct tc_cls_u32_offload *cls)
+{
+	int ret;
+
+	/* Set entry and fragments as not used */
+	tc_unfill_entry(priv, cls);
+
+	ret = stmmac_rxp_config(priv, priv->hw->pcsr, priv->tc_entries,
+			priv->tc_entries_max);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int tc_setup_cls_u32(struct stmmac_priv *priv,
+			    struct tc_cls_u32_offload *cls)
+{
+	switch (cls->command) {
+	case TC_CLSU32_REPLACE_KNODE:
+		tc_unfill_entry(priv, cls);
+		/* Fall through */
+	case TC_CLSU32_NEW_KNODE:
+		return tc_config_knode(priv, cls);
+	case TC_CLSU32_DELETE_KNODE:
+		return tc_delete_knode(priv, cls);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int tc_init(struct stmmac_priv *priv)
+{
+	struct dma_features *dma_cap = &priv->dma_cap;
+	unsigned int count;
+
+	if (!dma_cap->frpsel)
+		return -EINVAL;
+
+	switch (dma_cap->frpbs) {
+	case 0x0:
+		priv->tc_off_max = 64;
+		break;
+	case 0x1:
+		priv->tc_off_max = 128;
+		break;
+	case 0x2:
+		priv->tc_off_max = 256;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (dma_cap->frpes) {
+	case 0x0:
+		count = 64;
+		break;
+	case 0x1:
+		count = 128;
+		break;
+	case 0x2:
+		count = 256;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Reserve one last filter which lets all pass */
+	priv->tc_entries_max = count;
+	priv->tc_entries = devm_kzalloc(priv->device,
+			sizeof(*priv->tc_entries) * count, GFP_KERNEL);
+	if (!priv->tc_entries)
+		return -ENOMEM;
+
+	tc_fill_all_pass_entry(&priv->tc_entries[count - 1]);
+
+	dev_info(priv->device, "Enabling HW TC (entries=%d, max_off=%d)\n",
+			priv->tc_entries_max, priv->tc_off_max);
+	return 0;
+}
+
+const struct stmmac_tc_ops dwmac510_tc_ops = {
+	.init = tc_init,
+	.setup_cls_u32 = tc_setup_cls_u32,
+};