ieee80211: add new VHT capability fields/parsing

IEEE 802.11-2016 extended the VHT capability fields to allow
indicating the number of spatial streams depending on the
actually used bandwidth, add support for decoding this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 6c75148d4c9bd2349038630464d3dcf137e9e1e0..9fa250078933d2431fe5278ab6c480001909fe68 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1479,13 +1479,16 @@ struct ieee80211_ht_operation {
  *     STA can receive. Rate expressed in units of 1 Mbps.
  *     If this field is 0 this value should not be used to
  *     consider the highest RX data rate supported.
- *     The top 3 bits of this field are reserved.
+ *     The top 3 bits of this field indicate the Maximum NSTS,total
+ *     (a beamformee capability.)
  * @tx_mcs_map: TX MCS map 2 bits for each stream, total 8 streams
  * @tx_highest: Indicates highest long GI VHT PPDU data rate
  *     STA can transmit. Rate expressed in units of 1 Mbps.
  *     If this field is 0 this value should not be used to
  *     consider the highest TX data rate supported.
- *     The top 3 bits of this field are reserved.
+ *     The top 2 bits of this field are reserved, the
+ *     3rd bit from the top indiciates VHT Extended NSS BW
+ *     Capability.
  */
 struct ieee80211_vht_mcs_info {
        __le16 rx_mcs_map;
@@ -1494,6 +1497,13 @@ struct ieee80211_vht_mcs_info {
        __le16 tx_highest;
 } __packed;
 
+/* for rx_highest */
+#define IEEE80211_VHT_MAX_NSTS_TOTAL_SHIFT     13
+#define IEEE80211_VHT_MAX_NSTS_TOTAL_MASK      (7 << IEEE80211_VHT_MAX_NSTS_TOTAL_SHIFT)
+
+/* for tx_highest */
+#define IEEE80211_VHT_EXT_NSS_BW_CAPABLE       (1 << 13)
+
 /**
  * enum ieee80211_vht_mcs_support - VHT MCS support definitions
  * @IEEE80211_VHT_MCS_SUPPORT_0_7: MCSes 0-7 are supported for the
@@ -1668,6 +1678,8 @@ struct ieee80211_mu_edca_param_set {
 #define IEEE80211_VHT_CAP_MAX_MPDU_MASK                                0x00000003
 #define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ               0x00000004
 #define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ      0x00000008
+#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK                 0x0000000C
+#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_SHIFT                        2
 #define IEEE80211_VHT_CAP_RXLDPC                               0x00000010
 #define IEEE80211_VHT_CAP_SHORT_GI_80                          0x00000020
 #define IEEE80211_VHT_CAP_SHORT_GI_160                         0x00000040
@@ -1696,6 +1708,26 @@ struct ieee80211_mu_edca_param_set {
 #define IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB      0x0c000000
 #define IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN                   0x10000000
 #define IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN                   0x20000000
+#define IEEE80211_VHT_CAP_EXT_NSS_BW_SHIFT                     30
+#define IEEE80211_VHT_CAP_EXT_NSS_BW_MASK                      0xc0000000
+
+/**
+ * ieee80211_get_vht_max_nss - return max NSS for a given bandwidth/MCS
+ * @cap: VHT capabilities of the peer
+ * @bw: bandwidth to use
+ * @mcs: MCS index to use
+ * @ext_nss_bw_capable: indicates whether or not the local transmitter
+ *     (rate scaling algorithm) can deal with the new logic
+ *     (dot11VHTExtendedNSSBWCapable)
+ *
+ * Due to the VHT Extended NSS Bandwidth Support, the maximum NSS can
+ * vary for a given BW/MCS. This function parses the data.
+ *
+ * Note: This function is exported by cfg80211.
+ */
+int ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap,
+                             enum ieee80211_vht_chanwidth bw,
+                             int mcs, bool ext_nss_bw_capable);
 
 /* 802.11ax HE MAC capabilities */
 #define IEEE80211_HE_MAC_CAP0_HTC_HE                           0x01