mac80211: add STBC flag for radiotap

Some chips can tell us if received frame was
encoded with STBC or not. To make this information available
in user space we can use updated radiotap specification:
http://www.radiotap.org/defined-fields/MCS

This patch will set number of STBC encoded spatial streams (Nss).
The HAVE_STBC flag should be provided by driver.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index c399963..c6d07cb 100644 (file)
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -269,6 +269,7 @@ enum ieee80211_radiotap_type {
 #define IEEE80211_RADIOTAP_MCS_HAVE_GI         0x04
 #define IEEE80211_RADIOTAP_MCS_HAVE_FMT                0x08
 #define IEEE80211_RADIOTAP_MCS_HAVE_FEC                0x10
+#define IEEE80211_RADIOTAP_MCS_HAVE_STBC       0x20
 
 #define IEEE80211_RADIOTAP_MCS_BW_MASK         0x03
 #define                IEEE80211_RADIOTAP_MCS_BW_20    0
@@ -278,6 +279,12 @@ enum ieee80211_radiotap_type {
 #define IEEE80211_RADIOTAP_MCS_SGI             0x04
 #define IEEE80211_RADIOTAP_MCS_FMT_GF          0x08
 #define IEEE80211_RADIOTAP_MCS_FEC_LDPC                0x10
+#define IEEE80211_RADIOTAP_MCS_STBC_MASK       0x60
+#define                IEEE80211_RADIOTAP_MCS_STBC_1   1
+#define                IEEE80211_RADIOTAP_MCS_STBC_2   2
+#define                IEEE80211_RADIOTAP_MCS_STBC_3   3
+
+#define IEEE80211_RADIOTAP_MCS_STBC_SHIFT      5
 
 /* For IEEE80211_RADIOTAP_AMPDU_STATUS */
 #define IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN                0x0001

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index c36535e..c9e6fb7 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -805,6 +805,7 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
  *     on this subframe
  * @RX_FLAG_AMPDU_DELIM_CRC_KNOWN: The delimiter CRC field is known (the CRC
  *     is stored in the @ampdu_delimiter_crc field)
+ * @RX_FLAG_STBC_MASK: STBC 2 bit bitmask. 1 - Nss=1, 2 - Nss=2, 3 - Nss=3
  */
 enum mac80211_rx_flags {
        RX_FLAG_MMIC_ERROR              = BIT(0),
@@ -832,8 +833,11 @@ enum mac80211_rx_flags {
        RX_FLAG_80MHZ                   = BIT(23),
        RX_FLAG_80P80MHZ                = BIT(24),
        RX_FLAG_160MHZ                  = BIT(25),
+       RX_FLAG_STBC_MASK               = BIT(26) | BIT(27),
 };
 
+#define RX_FLAG_STBC_SHIFT             26
+
 /**
  * struct ieee80211_rx_status - receive status
  *

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6e2c8c5..7507f7c 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -258,6 +258,8 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
        pos += 2;
 
        if (status->flag & RX_FLAG_HT) {
+               unsigned int stbc;
+
                rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
                *pos++ = local->hw.radiotap_mcs_details;
                *pos = 0;
@@ -267,6 +269,8 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
                        *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
                if (status->flag & RX_FLAG_HT_GF)
                        *pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
+               stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
+               *pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
                pos++;
                *pos++ = status->rate_idx;
        }