cfg80211/nl80211: Add packet coalesce support

In most cases, host that receives IPv4 and IPv6 multicast/broadcast
packets does not do anything with these packets. Therefore the
reception of these unwanted packets causes unnecessary processing
and power consumption.

Packet coalesce feature helps to reduce number of received
interrupts to host by buffering these packets in firmware/hardware
for some predefined time. Received interrupt will be generated when
one of the following events occur.
a) Expiration of hardware timer whose expiration time is set to
maximum coalescing delay of matching coalesce rule.
b) Coalescing buffer in hardware reaches it's limit.
c) Packet doesn't match any of the configured coalesce rules.

This patch adds set/get configuration support for packet coalesce.
User needs to configure following parameters for creating a coalesce
rule.
a) Maximum coalescing delay
b) List of packet patterns which needs to be matched
c) Condition for coalescence. pattern 'match' or 'no match'
Multiple such rules can be created.

This feature needs to be advertised during driver initialization.
Drivers are supposed to do required firmware/hardware settings based
on user configuration.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
[fix kernel-doc, change free function, fix copy/paste error]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

4 files changed, 321 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 4f9f216..389a3f2 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -462,6 +462,14 @@ int wiphy_register(struct wiphy *wiphy)
 		return -EINVAL;
 #endif
 
+	if (WARN_ON(wiphy->coalesce &&
+		    (!wiphy->coalesce->n_rules ||
+		     !wiphy->coalesce->n_patterns) &&
+		    (!wiphy->coalesce->pattern_min_len ||
+		     wiphy->coalesce->pattern_min_len >
+			wiphy->coalesce->pattern_max_len)))
+		return -EINVAL;
+
 	if (WARN_ON(wiphy->ap_sme_capa &&
 		    !(wiphy->flags & WIPHY_FLAG_HAVE_AP_SME)))
 		return -EINVAL;
@@ -668,6 +676,7 @@ void wiphy_unregister(struct wiphy *wiphy)
 		rdev_set_wakeup(rdev, false);
 #endif
 	cfg80211_rdev_free_wowlan(rdev);
+	cfg80211_rdev_free_coalesce(rdev);
 }
 EXPORT_SYMBOL(wiphy_unregister);
 
diff --git a/net/wireless/core.h b/net/wireless/core.h
index a6b45bf..9ad43c6 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -79,6 +79,8 @@ struct cfg80211_registered_device {
 	/* netlink port which started critical protocol (0 means not started) */
 	u32 crit_proto_nlportid;
 
+	struct cfg80211_coalesce *coalesce;
+
 	/* must be last because of the way we do wiphy_priv(),
 	 * and it should at least be aligned to NETDEV_ALIGN */
 	struct wiphy wiphy __aligned(NETDEV_ALIGN);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0492478..6dca5a7 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -403,6 +403,14 @@ nl80211_wowlan_tcp_policy[NUM_NL80211_WOWLAN_TCP] = {
 	[NL80211_WOWLAN_TCP_WAKE_MASK] = { .len = 1 },
 };
 
+/* policy for coalesce rule attributes */
+static const struct nla_policy
+nl80211_coalesce_policy[NUM_NL80211_ATTR_COALESCE_RULE] = {
+	[NL80211_ATTR_COALESCE_RULE_DELAY] = { .type = NLA_U32 },
+	[NL80211_ATTR_COALESCE_RULE_CONDITION] = { .type = NLA_U32 },
+	[NL80211_ATTR_COALESCE_RULE_PKT_PATTERN] = { .type = NLA_NESTED },
+};
+
 /* policy for GTK rekey offload attributes */
 static const struct nla_policy
 nl80211_rekey_policy[NUM_NL80211_REKEY_DATA] = {
@@ -995,6 +1003,27 @@ static int nl80211_send_wowlan(struct sk_buff *msg,
 }
 #endif
 
+static int nl80211_send_coalesce(struct sk_buff *msg,
+				 struct cfg80211_registered_device *dev)
+{
+	struct nl80211_coalesce_rule_support rule;
+
+	if (!dev->wiphy.coalesce)
+		return 0;
+
+	rule.max_rules = dev->wiphy.coalesce->n_rules;
+	rule.max_delay = dev->wiphy.coalesce->max_delay;
+	rule.pat.max_patterns = dev->wiphy.coalesce->n_patterns;
+	rule.pat.min_pattern_len = dev->wiphy.coalesce->pattern_min_len;
+	rule.pat.max_pattern_len = dev->wiphy.coalesce->pattern_max_len;
+	rule.pat.max_pkt_offset = dev->wiphy.coalesce->max_pkt_offset;
+
+	if (nla_put(msg, NL80211_ATTR_COALESCE_RULE, sizeof(rule), &rule))
+		return -ENOBUFS;
+
+	return 0;
+}
+
 static int nl80211_send_band_rateinfo(struct sk_buff *msg,
 				      struct ieee80211_supported_band *sband)
 {
@@ -1513,6 +1542,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
 			    dev->wiphy.vht_capa_mod_mask))
 			goto nla_put_failure;
 
+		state->split_start++;
+		break;
+	case 10:
+		if (nl80211_send_coalesce(msg, dev))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;
@@ -8043,6 +8078,264 @@ static int nl80211_set_wowlan(struct sk_buff *skb, struct genl_info *info)
 }
 #endif
 
+static int nl80211_send_coalesce_rules(struct sk_buff *msg,
+				       struct cfg80211_registered_device *rdev)
+{
+	struct nlattr *nl_pats, *nl_pat, *nl_rule, *nl_rules;
+	int i, j, pat_len;
+	struct cfg80211_coalesce_rules *rule;
+
+	if (!rdev->coalesce->n_rules)
+		return 0;
+
+	nl_rules = nla_nest_start(msg, NL80211_ATTR_COALESCE_RULE);
+	if (!nl_rules)
+		return -ENOBUFS;
+
+	for (i = 0; i < rdev->coalesce->n_rules; i++) {
+		nl_rule = nla_nest_start(msg, i + 1);
+		if (!nl_rule)
+			return -ENOBUFS;
+
+		rule = &rdev->coalesce->rules[i];
+		if (nla_put_u32(msg, NL80211_ATTR_COALESCE_RULE_DELAY,
+				rule->delay))
+			return -ENOBUFS;
+
+		if (nla_put_u32(msg, NL80211_ATTR_COALESCE_RULE_CONDITION,
+				rule->condition))
+			return -ENOBUFS;
+
+		nl_pats = nla_nest_start(msg,
+				NL80211_ATTR_COALESCE_RULE_PKT_PATTERN);
+		if (!nl_pats)
+			return -ENOBUFS;
+
+		for (j = 0; j < rule->n_patterns; j++) {
+			nl_pat = nla_nest_start(msg, j + 1);
+			if (!nl_pat)
+				return -ENOBUFS;
+			pat_len = rule->patterns[j].pattern_len;
+			if (nla_put(msg, NL80211_PKTPAT_MASK,
+				    DIV_ROUND_UP(pat_len, 8),
+				    rule->patterns[j].mask) ||
+			    nla_put(msg, NL80211_PKTPAT_PATTERN, pat_len,
+				    rule->patterns[j].pattern) ||
+			    nla_put_u32(msg, NL80211_PKTPAT_OFFSET,
+					rule->patterns[j].pkt_offset))
+				return -ENOBUFS;
+			nla_nest_end(msg, nl_pat);
+		}
+		nla_nest_end(msg, nl_pats);
+		nla_nest_end(msg, nl_rule);
+	}
+	nla_nest_end(msg, nl_rules);
+
+	return 0;
+}
+
+static int nl80211_get_coalesce(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct sk_buff *msg;
+	void *hdr;
+
+	if (!rdev->wiphy.coalesce)
+		return -EOPNOTSUPP;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = nl80211hdr_put(msg, info->snd_portid, info->snd_seq, 0,
+			     NL80211_CMD_GET_COALESCE);
+	if (!hdr)
+		goto nla_put_failure;
+
+	if (rdev->coalesce && nl80211_send_coalesce_rules(msg, rdev))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+	return genlmsg_reply(msg, info);
+
+nla_put_failure:
+	nlmsg_free(msg);
+	return -ENOBUFS;
+}
+
+void cfg80211_rdev_free_coalesce(struct cfg80211_registered_device *rdev)
+{
+	struct cfg80211_coalesce *coalesce = rdev->coalesce;
+	int i, j;
+	struct cfg80211_coalesce_rules *rule;
+
+	if (!coalesce)
+		return;
+
+	for (i = 0; i < coalesce->n_rules; i++) {
+		rule = &coalesce->rules[i];
+		for (j = 0; j < rule->n_patterns; j++)
+			kfree(rule->patterns[j].mask);
+		kfree(rule->patterns);
+	}
+	kfree(coalesce->rules);
+	kfree(coalesce);
+	rdev->coalesce = NULL;
+}
+
+static int nl80211_parse_coalesce_rule(struct cfg80211_registered_device *rdev,
+				       struct nlattr *rule,
+				       struct cfg80211_coalesce_rules *new_rule)
+{
+	int err, i;
+	const struct wiphy_coalesce_support *coalesce = rdev->wiphy.coalesce;
+	struct nlattr *tb[NUM_NL80211_ATTR_COALESCE_RULE], *pat;
+	int rem, pat_len, mask_len, pkt_offset, n_patterns = 0;
+	struct nlattr *pat_tb[NUM_NL80211_PKTPAT];
+
+	err = nla_parse(tb, NL80211_ATTR_COALESCE_RULE_MAX, nla_data(rule),
+			nla_len(rule), nl80211_coalesce_policy);
+	if (err)
+		return err;
+
+	if (tb[NL80211_ATTR_COALESCE_RULE_DELAY])
+		new_rule->delay =
+			nla_get_u32(tb[NL80211_ATTR_COALESCE_RULE_DELAY]);
+	if (new_rule->delay > coalesce->max_delay)
+		return -EINVAL;
+
+	if (tb[NL80211_ATTR_COALESCE_RULE_CONDITION])
+		new_rule->condition =
+			nla_get_u32(tb[NL80211_ATTR_COALESCE_RULE_CONDITION]);
+	if (new_rule->condition != NL80211_COALESCE_CONDITION_MATCH &&
+	    new_rule->condition != NL80211_COALESCE_CONDITION_NO_MATCH)
+		return -EINVAL;
+
+	if (!tb[NL80211_ATTR_COALESCE_RULE_PKT_PATTERN])
+		return -EINVAL;
+
+	nla_for_each_nested(pat, tb[NL80211_ATTR_COALESCE_RULE_PKT_PATTERN],
+			    rem)
+		n_patterns++;
+	if (n_patterns > coalesce->n_patterns)
+		return -EINVAL;
+
+	new_rule->patterns = kcalloc(n_patterns, sizeof(new_rule->patterns[0]),
+				     GFP_KERNEL);
+	if (!new_rule->patterns)
+		return -ENOMEM;
+
+	new_rule->n_patterns = n_patterns;
+	i = 0;
+
+	nla_for_each_nested(pat, tb[NL80211_ATTR_COALESCE_RULE_PKT_PATTERN],
+			    rem) {
+		nla_parse(pat_tb, MAX_NL80211_PKTPAT, nla_data(pat),
+			  nla_len(pat), NULL);
+		if (!pat_tb[NL80211_PKTPAT_MASK] ||
+		    !pat_tb[NL80211_PKTPAT_PATTERN])
+			return -EINVAL;
+		pat_len = nla_len(pat_tb[NL80211_PKTPAT_PATTERN]);
+		mask_len = DIV_ROUND_UP(pat_len, 8);
+		if (nla_len(pat_tb[NL80211_PKTPAT_MASK]) != mask_len)
+			return -EINVAL;
+		if (pat_len > coalesce->pattern_max_len ||
+		    pat_len < coalesce->pattern_min_len)
+			return -EINVAL;
+
+		if (!pat_tb[NL80211_PKTPAT_OFFSET])
+			pkt_offset = 0;
+		else
+			pkt_offset = nla_get_u32(pat_tb[NL80211_PKTPAT_OFFSET]);
+		if (pkt_offset > coalesce->max_pkt_offset)
+			return -EINVAL;
+		new_rule->patterns[i].pkt_offset = pkt_offset;
+
+		new_rule->patterns[i].mask =
+			kmalloc(mask_len + pat_len, GFP_KERNEL);
+		if (!new_rule->patterns[i].mask)
+			return -ENOMEM;
+		new_rule->patterns[i].pattern =
+			new_rule->patterns[i].mask + mask_len;
+		memcpy(new_rule->patterns[i].mask,
+		       nla_data(pat_tb[NL80211_PKTPAT_MASK]), mask_len);
+		new_rule->patterns[i].pattern_len = pat_len;
+		memcpy(new_rule->patterns[i].pattern,
+		       nla_data(pat_tb[NL80211_PKTPAT_PATTERN]), pat_len);
+		i++;
+	}
+
+	return 0;
+}
+
+static int nl80211_set_coalesce(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	const struct wiphy_coalesce_support *coalesce = rdev->wiphy.coalesce;
+	struct cfg80211_coalesce new_coalesce = {};
+	struct cfg80211_coalesce *n_coalesce;
+	int err, rem_rule, n_rules = 0, i, j;
+	struct nlattr *rule;
+	struct cfg80211_coalesce_rules *tmp_rule;
+
+	if (!rdev->wiphy.coalesce || !rdev->ops->set_coalesce)
+		return -EOPNOTSUPP;
+
+	if (!info->attrs[NL80211_ATTR_COALESCE_RULE]) {
+		cfg80211_rdev_free_coalesce(rdev);
+		rdev->ops->set_coalesce(&rdev->wiphy, NULL);
+		return 0;
+	}
+
+	nla_for_each_nested(rule, info->attrs[NL80211_ATTR_COALESCE_RULE],
+			    rem_rule)
+		n_rules++;
+	if (n_rules > coalesce->n_rules)
+		return -EINVAL;
+
+	new_coalesce.rules = kcalloc(n_rules, sizeof(new_coalesce.rules[0]),
+				     GFP_KERNEL);
+	if (!new_coalesce.rules)
+		return -ENOMEM;
+
+	new_coalesce.n_rules = n_rules;
+	i = 0;
+
+	nla_for_each_nested(rule, info->attrs[NL80211_ATTR_COALESCE_RULE],
+			    rem_rule) {
+		err = nl80211_parse_coalesce_rule(rdev, rule,
+						  &new_coalesce.rules[i]);
+		if (err)
+			goto error;
+
+		i++;
+	}
+
+	err = rdev->ops->set_coalesce(&rdev->wiphy, &new_coalesce);
+	if (err)
+		goto error;
+
+	n_coalesce = kmemdup(&new_coalesce, sizeof(new_coalesce), GFP_KERNEL);
+	if (!n_coalesce) {
+		err = -ENOMEM;
+		goto error;
+	}
+	cfg80211_rdev_free_coalesce(rdev);
+	rdev->coalesce = n_coalesce;
+
+	return 0;
+error:
+	for (i = 0; i < new_coalesce.n_rules; i++) {
+		tmp_rule = &new_coalesce.rules[i];
+		for (j = 0; j < tmp_rule->n_patterns; j++)
+			kfree(tmp_rule->patterns[j].mask);
+		kfree(tmp_rule->patterns);
+	}
+	kfree(new_coalesce.rules);
+
+	return err;
+}
+
 static int nl80211_set_rekey_data(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -9050,6 +9343,21 @@ static struct genl_ops nl80211_ops[] = {
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = NL80211_FLAG_NEED_WDEV_UP |
 				  NL80211_FLAG_NEED_RTNL,
+	},
+	{
+		.cmd = NL80211_CMD_GET_COALESCE,
+		.doit = nl80211_get_coalesce,
+		.policy = nl80211_policy,
+		.internal_flags = NL80211_FLAG_NEED_WIPHY |
+				  NL80211_FLAG_NEED_RTNL,
+	},
+	{
+		.cmd = NL80211_CMD_SET_COALESCE,
+		.doit = nl80211_set_coalesce,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL80211_FLAG_NEED_WIPHY |
+				  NL80211_FLAG_NEED_RTNL,
 	}
 };
 
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index a4073e8..44341bf 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -74,4 +74,6 @@ nl80211_radar_notify(struct cfg80211_registered_device *rdev,
 		     enum nl80211_radar_event event,
 		     struct net_device *netdev, gfp_t gfp);
 
+void cfg80211_rdev_free_coalesce(struct cfg80211_registered_device *rdev);
+
 #endif /* __NET_WIRELESS_NL80211_H */