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From:   Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
To:     <johannes@sipsolutions.net>
CC:     <linux-wireless@vger.kernel.org>
Subject: [RFC 2/4] wifi: nl80211: send underlying multi-hardware channel capabilities to user space
Date:   Tue, 20 Sep 2022 15:35:16 +0530
Message-ID: <20220920100518.19705-3-quic_vthiagar@quicinc.com>
In-Reply-To: <20220920100518.19705-1-quic_vthiagar@quicinc.com>
References: <20220920100518.19705-1-quic_vthiagar@quicinc.com>
MIME-Version: 1.0
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When driver supports multiple physical hardware under one wiphy,
wiphy->num_hw != 0, send per-hardware supported frequency list to
user space. List of frequency are reported inside an index which
identifies the hardware as in wiphy->hw_chans[]. This hardware index
will be used in follow up patches to identify the interface combination
capability for each of the underlying physical hardware abstracted
under one wiphy.

Signed-off-by: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
---
 include/uapi/linux/nl80211.h | 28 +++++++++++++++++++++
 net/wireless/nl80211.c       | 47 ++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c32e7616a366..070b31277402 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2749,6 +2749,12 @@ enum nl80211_commands {
  *	When used with %NL80211_CMD_FRAME_TX_STATUS, indicates the ack RX
  *	timestamp. When used with %NL80211_CMD_FRAME RX notification, indicates
  *	the incoming frame RX timestamp.
+ *
+ * @NL80211_ATTR_MULTI_HW_MACS: nested attribute to send the hardware mac
+ *	specific channel capabilities to user space. Drivers registering
+ *	multiple physical hardware under a wiphy can use this attribute,
+ *	see &enum nl80211_multi_hw_mac_attrs.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3277,6 +3283,8 @@ enum nl80211_attrs {
 	NL80211_ATTR_TX_HW_TIMESTAMP,
 	NL80211_ATTR_RX_HW_TIMESTAMP,
 
+	NL80211_ATTR_MULTI_HW_MACS,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -7720,4 +7728,24 @@ enum nl80211_ap_settings_flags {
 	NL80211_AP_SETTINGS_SA_QUERY_OFFLOAD_SUPPORT	= 1 << 1,
 };
 
+/**
+ * nl80211_multi_hw_mac_attrs - multi-hw mac attributes
+ *
+ * @NL80211_MULTI_HW_MAC_ATTR_INVALID: invalid
+ * @NL80211_MULTI_HW_MAC_ATTR_IDX: (u8) array index in wiphy @hw_chans to refer an
+ *	underlying hw mac for which the supported channel list is advertised.
+ * @NL80211_MULTI_HW_MAC_ATTR_FREQS: array of supported center frequencies
+ * @__NL80211_MULTI_HW_MAC_ATTR_LAST: internal use
+ * @NL80211_MULTI_HW_MAC_ATTR_MAX: maximum multi-hw mac attribute
+ */
+enum nl80211_multi_hw_mac_attrs {
+	__NL80211_MULTI_HW_MAC_ATTR_INVALID,
+
+	NL80211_MULTI_HW_MAC_ATTR_IDX,
+	NL80211_MULTI_HW_MAC_ATTR_FREQS,
+
+	/* keep last */
+	__NL80211_MULTI_HW_MAC_ATTR_LAST,
+	NL80211_MULTI_HW_MAC_ATTR_MAX = __NL80211_MULTI_HW_MAC_ATTR_LAST - 1
+};
 #endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 8ff8b1c040f0..b7d466010e81 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2355,6 +2355,47 @@ static int nl80211_put_mbssid_support(struct wiphy *wiphy, struct sk_buff *msg)
 	return -ENOBUFS;
 }
 
+static int nl80211_put_multi_hw_support(struct wiphy *wiphy,
+					struct sk_buff *msg)
+{
+	struct nlattr *hw_macs, *hw_mac;
+	struct nlattr *freqs;
+	int i, c;
+
+	if (!wiphy->num_hw)
+		return 0;
+
+	hw_macs = nla_nest_start(msg, NL80211_ATTR_MULTI_HW_MACS);
+	if (!hw_macs)
+		return -ENOBUFS;
+
+	for (i = 0; i < wiphy->num_hw; i++) {
+		hw_mac = nla_nest_start(msg, i + 1);
+		if (!hw_mac)
+			return -ENOBUFS;
+
+		if (nla_put_u8(msg, NL80211_MULTI_HW_MAC_ATTR_IDX, i))
+			return -ENOBUFS;
+
+		freqs = nla_nest_start(msg,
+				       NL80211_MULTI_HW_MAC_ATTR_FREQS);
+		if (!freqs)
+			return -ENOBUFS;
+
+		for (c = 0; c < wiphy->hw_chans[i]->n_chans; c++)
+			if (nla_put_u32(msg, c + 1,
+					wiphy->hw_chans[i]->chans[c].center_freq))
+				return -ENOBUFS;
+
+		nla_nest_end(msg, freqs);
+
+		nla_nest_end(msg, hw_mac);
+	}
+
+	nla_nest_end(msg, hw_macs);
+	return 0;
+}
+
 struct nl80211_dump_wiphy_state {
 	s64 filter_wiphy;
 	long start;
@@ -2959,6 +3000,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 		if (rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_MLO)
 			nla_put_flag(msg, NL80211_ATTR_MLO_SUPPORT);
 
+		state->split_start++;
+		break;
+	case 17:
+		if (nl80211_put_multi_hw_support(&rdev->wiphy, msg))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;
-- 
2.17.1