nfp: add metadata to each flow offload

Adds metadata describing the mask id of each flow and keeps track of
flows installed in hardware. Previously a flow could not be removed
from hardware as there was no way of knowing if that a specific flow
was installed. This is solved by storing the offloaded flows in a
hash table.

Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/flower/metadata.c b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
new file mode 100644
index 000000000000..8a359ef3cc27
--- /dev/null
+++ b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
@@ -0,0 +1,318 @@
+/*
+ * Copyright (C) 2017 Netronome Systems, Inc.
+ *
+ * This software is dual licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree or the BSD 2-Clause License provided below.  You have the
+ * option to license this software under the complete terms of either license.
+ *
+ * The BSD 2-Clause License:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      1. Redistributions of source code must retain the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer.
+ *
+ *      2. 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 <linux/hash.h>
+#include <linux/hashtable.h>
+#include <linux/jhash.h>
+#include <linux/vmalloc.h>
+#include <net/pkt_cls.h>
+
+#include "cmsg.h"
+#include "main.h"
+#include "../nfp_app.h"
+
+struct nfp_mask_id_table {
+	struct hlist_node link;
+	u32 hash_key;
+	u32 ref_cnt;
+	u8 mask_id;
+};
+
+/* Must be called with either RTNL or rcu_read_lock */
+struct nfp_fl_payload *
+nfp_flower_search_fl_table(struct nfp_app *app, unsigned long tc_flower_cookie)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct nfp_fl_payload *flower_entry;
+
+	hash_for_each_possible_rcu(priv->flow_table, flower_entry, link,
+				   tc_flower_cookie)
+		if (flower_entry->tc_flower_cookie == tc_flower_cookie)
+			return flower_entry;
+
+	return NULL;
+}
+
+static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct circ_buf *ring;
+	struct timespec64 now;
+
+	ring = &priv->mask_ids.mask_id_free_list;
+	/* Checking if buffer is full. */
+	if (CIRC_SPACE(ring->head, ring->tail, NFP_FLOWER_MASK_ENTRY_RS) == 0)
+		return -ENOBUFS;
+
+	memcpy(&ring->buf[ring->head], &mask_id, NFP_FLOWER_MASK_ELEMENT_RS);
+	ring->head = (ring->head + NFP_FLOWER_MASK_ELEMENT_RS) %
+		     (NFP_FLOWER_MASK_ENTRY_RS * NFP_FLOWER_MASK_ELEMENT_RS);
+
+	getnstimeofday64(&now);
+	priv->mask_ids.last_used[mask_id] = now;
+
+	return 0;
+}
+
+static int nfp_mask_alloc(struct nfp_app *app, u8 *mask_id)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct timespec64 delta, now;
+	struct circ_buf *ring;
+	u8 temp_id, freed_id;
+
+	ring = &priv->mask_ids.mask_id_free_list;
+	freed_id = NFP_FLOWER_MASK_ENTRY_RS - 1;
+	/* Checking for unallocated entries first. */
+	if (priv->mask_ids.init_unallocated > 0) {
+		*mask_id = priv->mask_ids.init_unallocated;
+		priv->mask_ids.init_unallocated--;
+		return 0;
+	}
+
+	/* Checking if buffer is empty. */
+	if (ring->head == ring->tail)
+		goto err_not_found;
+
+	memcpy(&temp_id, &ring->buf[ring->tail], NFP_FLOWER_MASK_ELEMENT_RS);
+	*mask_id = temp_id;
+
+	getnstimeofday64(&now);
+	delta = timespec64_sub(now, priv->mask_ids.last_used[*mask_id]);
+
+	if (timespec64_to_ns(&delta) < NFP_FL_MASK_REUSE_TIME_NS)
+		goto err_not_found;
+
+	memcpy(&ring->buf[ring->tail], &freed_id, NFP_FLOWER_MASK_ELEMENT_RS);
+	ring->tail = (ring->tail + NFP_FLOWER_MASK_ELEMENT_RS) %
+		     (NFP_FLOWER_MASK_ENTRY_RS * NFP_FLOWER_MASK_ELEMENT_RS);
+
+	return 0;
+
+err_not_found:
+	*mask_id = freed_id;
+	return -ENOENT;
+}
+
+static int
+nfp_add_mask_table(struct nfp_app *app, char *mask_data, u32 mask_len)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct nfp_mask_id_table *mask_entry;
+	unsigned long hash_key;
+	u8 mask_id;
+
+	if (nfp_mask_alloc(app, &mask_id))
+		return -ENOENT;
+
+	mask_entry = kmalloc(sizeof(*mask_entry), GFP_KERNEL);
+	if (!mask_entry) {
+		nfp_release_mask_id(app, mask_id);
+		return -ENOMEM;
+	}
+
+	INIT_HLIST_NODE(&mask_entry->link);
+	mask_entry->mask_id = mask_id;
+	hash_key = jhash(mask_data, mask_len, priv->mask_id_seed);
+	mask_entry->hash_key = hash_key;
+	mask_entry->ref_cnt = 1;
+	hash_add(priv->mask_table, &mask_entry->link, hash_key);
+
+	return mask_id;
+}
+
+static struct nfp_mask_id_table *
+nfp_search_mask_table(struct nfp_app *app, char *mask_data, u32 mask_len)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct nfp_mask_id_table *mask_entry;
+	unsigned long hash_key;
+
+	hash_key = jhash(mask_data, mask_len, priv->mask_id_seed);
+
+	hash_for_each_possible(priv->mask_table, mask_entry, link, hash_key)
+		if (mask_entry->hash_key == hash_key)
+			return mask_entry;
+
+	return NULL;
+}
+
+static int
+nfp_find_in_mask_table(struct nfp_app *app, char *mask_data, u32 mask_len)
+{
+	struct nfp_mask_id_table *mask_entry;
+
+	mask_entry = nfp_search_mask_table(app, mask_data, mask_len);
+	if (!mask_entry)
+		return -ENOENT;
+
+	mask_entry->ref_cnt++;
+
+	/* Casting u8 to int for later use. */
+	return mask_entry->mask_id;
+}
+
+static bool
+nfp_check_mask_add(struct nfp_app *app, char *mask_data, u32 mask_len,
+		   u8 *meta_flags, u8 *mask_id)
+{
+	int id;
+
+	id = nfp_find_in_mask_table(app, mask_data, mask_len);
+	if (id < 0) {
+		id = nfp_add_mask_table(app, mask_data, mask_len);
+		if (id < 0)
+			return false;
+		*meta_flags |= NFP_FL_META_FLAG_NEW_MASK;
+	}
+	*mask_id = id;
+
+	return true;
+}
+
+static bool
+nfp_check_mask_remove(struct nfp_app *app, char *mask_data, u32 mask_len,
+		      u8 *meta_flags, u8 *mask_id)
+{
+	struct nfp_mask_id_table *mask_entry;
+
+	mask_entry = nfp_search_mask_table(app, mask_data, mask_len);
+	if (!mask_entry)
+		return false;
+
+	*mask_id = mask_entry->mask_id;
+	mask_entry->ref_cnt--;
+	if (!mask_entry->ref_cnt) {
+		hash_del(&mask_entry->link);
+		nfp_release_mask_id(app, *mask_id);
+		kfree(mask_entry);
+		if (meta_flags)
+			*meta_flags |= NFP_FL_META_FLAG_LAST_MASK;
+	}
+
+	return true;
+}
+
+int nfp_compile_flow_metadata(struct nfp_app *app,
+			      struct tc_cls_flower_offload *flow,
+			      struct nfp_fl_payload *nfp_flow)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	struct nfp_fl_payload *check_entry;
+	u8 new_mask_id;
+
+	new_mask_id = 0;
+	if (!nfp_check_mask_add(app, nfp_flow->mask_data,
+				nfp_flow->meta.mask_len,
+				&nfp_flow->meta.flags, &new_mask_id))
+		return -ENOENT;
+
+	nfp_flow->meta.flow_version = cpu_to_be64(priv->flower_version);
+	priv->flower_version++;
+
+	/* Update flow payload with mask ids. */
+	nfp_flow->unmasked_data[NFP_FL_MASK_ID_LOCATION] = new_mask_id;
+
+	check_entry = nfp_flower_search_fl_table(app, flow->cookie);
+	if (check_entry) {
+		if (!nfp_check_mask_remove(app, nfp_flow->mask_data,
+					   nfp_flow->meta.mask_len,
+					   NULL, &new_mask_id))
+			return -EINVAL;
+
+		return -EEXIST;
+	}
+
+	return 0;
+}
+
+int nfp_modify_flow_metadata(struct nfp_app *app,
+			     struct nfp_fl_payload *nfp_flow)
+{
+	struct nfp_flower_priv *priv = app->priv;
+	u8 new_mask_id = 0;
+
+	nfp_check_mask_remove(app, nfp_flow->mask_data,
+			      nfp_flow->meta.mask_len, &nfp_flow->meta.flags,
+			      &new_mask_id);
+
+	nfp_flow->meta.flow_version = cpu_to_be64(priv->flower_version);
+	priv->flower_version++;
+
+	/* Update flow payload with mask ids. */
+	nfp_flow->unmasked_data[NFP_FL_MASK_ID_LOCATION] = new_mask_id;
+
+	return 0;
+}
+
+int nfp_flower_metadata_init(struct nfp_app *app)
+{
+	struct nfp_flower_priv *priv = app->priv;
+
+	hash_init(priv->mask_table);
+	hash_init(priv->flow_table);
+	get_random_bytes(&priv->mask_id_seed, sizeof(priv->mask_id_seed));
+
+	/* Init ring buffer and unallocated mask_ids. */
+	priv->mask_ids.mask_id_free_list.buf =
+		kmalloc_array(NFP_FLOWER_MASK_ENTRY_RS,
+			      NFP_FLOWER_MASK_ELEMENT_RS, GFP_KERNEL);
+	if (!priv->mask_ids.mask_id_free_list.buf)
+		return -ENOMEM;
+
+	priv->mask_ids.init_unallocated = NFP_FLOWER_MASK_ENTRY_RS - 1;
+
+	/* Init timestamps for mask id*/
+	priv->mask_ids.last_used =
+		kmalloc_array(NFP_FLOWER_MASK_ENTRY_RS,
+			      sizeof(*priv->mask_ids.last_used), GFP_KERNEL);
+	if (!priv->mask_ids.last_used)
+		goto err_free_mask_id;
+
+	return 0;
+
+err_free_mask_id:
+	kfree(priv->mask_ids.mask_id_free_list.buf);
+	return -ENOMEM;
+}
+
+void nfp_flower_metadata_cleanup(struct nfp_app *app)
+{
+	struct nfp_flower_priv *priv = app->priv;
+
+	if (!priv)
+		return;
+
+	kfree(priv->mask_ids.mask_id_free_list.buf);
+	kfree(priv->mask_ids.last_used);
+}