cxgb4: add support for offloading u32 filters

Add support for offloading u32 filter onto hardware.  Links are stored
in a jump table to perform necessary jumps to match TCP/UDP header.
When inserting rules in the linked bucket, the TCP/UDP match fields
in the corresponding entry of the jump table are appended to the filter
rule before insertion.  If a link is deleted, then all corresponding
filters associated with the link are also deleted.  Also enable
hardware tc offload as a supported feature.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 412 insertions, 0 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_u32.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_u32.c
new file mode 100644
index 000000000000..d63b8955ea05
--- /dev/null
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_u32.c
@@ -0,0 +1,412 @@
+/*
+ * This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "cxgb4.h"
+#include "cxgb4_tc_u32_parse.h"
+#include "cxgb4_tc_u32.h"
+
+/* Fill ch_filter_specification with parsed match value/mask pair. */
+static int fill_match_fields(struct adapter *adap,
+			     struct ch_filter_specification *fs,
+			     struct tc_cls_u32_offload *cls,
+			     const struct cxgb4_match_field *entry,
+			     bool next_header)
+{
+	unsigned int i, j;
+	u32 val, mask;
+	int off, err;
+	bool found;
+
+	for (i = 0; i < cls->knode.sel->nkeys; i++) {
+		off = cls->knode.sel->keys[i].off;
+		val = cls->knode.sel->keys[i].val;
+		mask = cls->knode.sel->keys[i].mask;
+
+		if (next_header) {
+			/* For next headers, parse only keys with offmask */
+			if (!cls->knode.sel->keys[i].offmask)
+				continue;
+		} else {
+			/* For the remaining, parse only keys without offmask */
+			if (cls->knode.sel->keys[i].offmask)
+				continue;
+		}
+
+		found = false;
+
+		for (j = 0; entry[j].val; j++) {
+			if (off == entry[j].off) {
+				found = true;
+				err = entry[j].val(fs, val, mask);
+				if (err)
+					return err;
+				break;
+			}
+		}
+
+		if (!found)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+int cxgb4_config_knode(struct net_device *dev, __be16 protocol,
+		       struct tc_cls_u32_offload *cls)
+{
+	const struct cxgb4_match_field *start, *link_start = NULL;
+	struct adapter *adapter = netdev2adap(dev);
+	struct ch_filter_specification fs;
+	struct cxgb4_tc_u32_table *t;
+	struct cxgb4_link *link;
+	unsigned int filter_id;
+	u32 uhtid, link_uhtid;
+	bool is_ipv6 = false;
+	int ret;
+
+	if (!can_tc_u32_offload(dev))
+		return -EOPNOTSUPP;
+
+	if (protocol != htons(ETH_P_IP) && protocol != htons(ETH_P_IPV6))
+		return -EOPNOTSUPP;
+
+	/* Fetch the location to insert the filter. */
+	filter_id = cls->knode.handle & 0xFFFFF;
+
+	if (filter_id > adapter->tids.nftids) {
+		dev_err(adapter->pdev_dev,
+			"Location %d out of range for insertion. Max: %d\n",
+			filter_id, adapter->tids.nftids);
+		return -ERANGE;
+	}
+
+	t = adapter->tc_u32;
+	uhtid = TC_U32_USERHTID(cls->knode.handle);
+	link_uhtid = TC_U32_USERHTID(cls->knode.link_handle);
+
+	/* Ensure that uhtid is either root u32 (i.e. 0x800)
+	 * or a a valid linked bucket.
+	 */
+	if (uhtid != 0x800 && uhtid >= t->size)
+		return -EINVAL;
+
+	/* Ensure link handle uhtid is sane, if specified. */
+	if (link_uhtid >= t->size)
+		return -EINVAL;
+
+	memset(&fs, 0, sizeof(fs));
+
+	if (protocol == htons(ETH_P_IPV6)) {
+		start = cxgb4_ipv6_fields;
+		is_ipv6 = true;
+	} else {
+		start = cxgb4_ipv4_fields;
+		is_ipv6 = false;
+	}
+
+	if (uhtid != 0x800) {
+		/* Link must exist from root node before insertion. */
+		if (!t->table[uhtid - 1].link_handle)
+			return -EINVAL;
+
+		/* Link must have a valid supported next header. */
+		link_start = t->table[uhtid - 1].match_field;
+		if (!link_start)
+			return -EINVAL;
+	}
+
+	/* Parse links and record them for subsequent jumps to valid
+	 * next headers.
+	 */
+	if (link_uhtid) {
+		const struct cxgb4_next_header *next;
+		bool found = false;
+		unsigned int i, j;
+		u32 val, mask;
+		int off;
+
+		if (t->table[link_uhtid - 1].link_handle) {
+			dev_err(adapter->pdev_dev,
+				"Link handle exists for: 0x%x\n",
+				link_uhtid);
+			return -EINVAL;
+		}
+
+		next = is_ipv6 ? cxgb4_ipv6_jumps : cxgb4_ipv4_jumps;
+
+		/* Try to find matches that allow jumps to next header. */
+		for (i = 0; next[i].jump; i++) {
+			if (next[i].offoff != cls->knode.sel->offoff ||
+			    next[i].shift != cls->knode.sel->offshift ||
+			    next[i].mask != cls->knode.sel->offmask ||
+			    next[i].offset != cls->knode.sel->off)
+				continue;
+
+			/* Found a possible candidate.  Find a key that
+			 * matches the corresponding offset, value, and
+			 * mask to jump to next header.
+			 */
+			for (j = 0; j < cls->knode.sel->nkeys; j++) {
+				off = cls->knode.sel->keys[j].off;
+				val = cls->knode.sel->keys[j].val;
+				mask = cls->knode.sel->keys[j].mask;
+
+				if (next[i].match_off == off &&
+				    next[i].match_val == val &&
+				    next[i].match_mask == mask) {
+					found = true;
+					break;
+				}
+			}
+
+			if (!found)
+				continue; /* Try next candidate. */
+
+			/* Candidate to jump to next header found.
+			 * Translate all keys to internal specification
+			 * and store them in jump table. This spec is copied
+			 * later to set the actual filters.
+			 */
+			ret = fill_match_fields(adapter, &fs, cls,
+						start, false);
+			if (ret)
+				goto out;
+
+			link = &t->table[link_uhtid - 1];
+			link->match_field = next[i].jump;
+			link->link_handle = cls->knode.handle;
+			memcpy(&link->fs, &fs, sizeof(fs));
+			break;
+		}
+
+		/* No candidate found to jump to next header. */
+		if (!found)
+			return -EINVAL;
+
+		return 0;
+	}
+
+	/* Fill ch_filter_specification match fields to be shipped to hardware.
+	 * Copy the linked spec (if any) first.  And then update the spec as
+	 * needed.
+	 */
+	if (uhtid != 0x800 && t->table[uhtid - 1].link_handle) {
+		/* Copy linked ch_filter_specification */
+		memcpy(&fs, &t->table[uhtid - 1].fs, sizeof(fs));
+		ret = fill_match_fields(adapter, &fs, cls,
+					link_start, true);
+		if (ret)
+			goto out;
+	}
+
+	ret = fill_match_fields(adapter, &fs, cls, start, false);
+	if (ret)
+		goto out;
+
+	/* The filter spec has been completely built from the info
+	 * provided from u32.  We now set some default fields in the
+	 * spec for sanity.
+	 */
+
+	/* Match only packets coming from the ingress port where this
+	 * filter will be created.
+	 */
+	fs.val.iport = netdev2pinfo(dev)->port_id;
+	fs.mask.iport = ~0;
+
+	/* Enable filter hit counts. */
+	fs.hitcnts = 1;
+
+	/* Set type of filter - IPv6 or IPv4 */
+	fs.type = is_ipv6 ? 1 : 0;
+
+	/* Set the filter */
+	ret = cxgb4_set_filter(dev, filter_id, &fs);
+	if (ret)
+		goto out;
+
+	/* If this is a linked bucket, then set the corresponding
+	 * entry in the bitmap to mark it as belonging to this linked
+	 * bucket.
+	 */
+	if (uhtid != 0x800 && t->table[uhtid - 1].link_handle)
+		set_bit(filter_id, t->table[uhtid - 1].tid_map);
+
+out:
+	return ret;
+}
+
+int cxgb4_delete_knode(struct net_device *dev, __be16 protocol,
+		       struct tc_cls_u32_offload *cls)
+{
+	struct adapter *adapter = netdev2adap(dev);
+	unsigned int filter_id, max_tids, i, j;
+	struct cxgb4_link *link = NULL;
+	struct cxgb4_tc_u32_table *t;
+	u32 handle, uhtid;
+	int ret;
+
+	if (!can_tc_u32_offload(dev))
+		return -EOPNOTSUPP;
+
+	/* Fetch the location to delete the filter. */
+	filter_id = cls->knode.handle & 0xFFFFF;
+
+	if (filter_id > adapter->tids.nftids) {
+		dev_err(adapter->pdev_dev,
+			"Location %d out of range for deletion. Max: %d\n",
+			filter_id, adapter->tids.nftids);
+		return -ERANGE;
+	}
+
+	t = adapter->tc_u32;
+	handle = cls->knode.handle;
+	uhtid = TC_U32_USERHTID(cls->knode.handle);
+
+	/* Ensure that uhtid is either root u32 (i.e. 0x800)
+	 * or a a valid linked bucket.
+	 */
+	if (uhtid != 0x800 && uhtid >= t->size)
+		return -EINVAL;
+
+	/* Delete the specified filter */
+	if (uhtid != 0x800) {
+		link = &t->table[uhtid - 1];
+		if (!link->link_handle)
+			return -EINVAL;
+
+		if (!test_bit(filter_id, link->tid_map))
+			return -EINVAL;
+	}
+
+	ret = cxgb4_del_filter(dev, filter_id);
+	if (ret)
+		goto out;
+
+	if (link)
+		clear_bit(filter_id, link->tid_map);
+
+	/* If a link is being deleted, then delete all filters
+	 * associated with the link.
+	 */
+	max_tids = adapter->tids.nftids;
+	for (i = 0; i < t->size; i++) {
+		link = &t->table[i];
+
+		if (link->link_handle == handle) {
+			for (j = 0; j < max_tids; j++) {
+				if (!test_bit(j, link->tid_map))
+					continue;
+
+				ret = __cxgb4_del_filter(dev, j, NULL);
+				if (ret)
+					goto out;
+
+				clear_bit(j, link->tid_map);
+			}
+
+			/* Clear the link state */
+			link->match_field = NULL;
+			link->link_handle = 0;
+			memset(&link->fs, 0, sizeof(link->fs));
+			break;
+		}
+	}
+
+out:
+	return ret;
+}
+
+void cxgb4_cleanup_tc_u32(struct adapter *adap)
+{
+	struct cxgb4_tc_u32_table *t;
+	unsigned int i;
+
+	if (!adap->tc_u32)
+		return;
+
+	/* Free up all allocated memory. */
+	t = adap->tc_u32;
+	for (i = 0; i < t->size; i++) {
+		struct cxgb4_link *link = &t->table[i];
+
+		t4_free_mem(link->tid_map);
+	}
+	t4_free_mem(adap->tc_u32);
+}
+
+struct cxgb4_tc_u32_table *cxgb4_init_tc_u32(struct adapter *adap,
+					     unsigned int size)
+{
+	struct cxgb4_tc_u32_table *t;
+	unsigned int i;
+
+	if (!size)
+		return NULL;
+
+	t = t4_alloc_mem(sizeof(*t) +
+			 (size * sizeof(struct cxgb4_link)));
+	if (!t)
+		return NULL;
+
+	t->size = size;
+
+	for (i = 0; i < t->size; i++) {
+		struct cxgb4_link *link = &t->table[i];
+		unsigned int bmap_size;
+		unsigned int max_tids;
+
+		max_tids = adap->tids.nftids;
+		bmap_size = BITS_TO_LONGS(max_tids);
+		link->tid_map = t4_alloc_mem(sizeof(unsigned long) * bmap_size);
+		if (!link->tid_map)
+			goto out_no_mem;
+		bitmap_zero(link->tid_map, max_tids);
+	}
+
+	return t;
+
+out_no_mem:
+	for (i = 0; i < t->size; i++) {
+		struct cxgb4_link *link = &t->table[i];
+
+		if (link->tid_map)
+			t4_free_mem(link->tid_map);
+	}
+
+	if (t)
+		t4_free_mem(t);
+
+	return NULL;
+}