On 14-2-2017 14:22, Johannes Berg wrote: > From: Johannes Berg <[email protected]> > > 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 <[email protected]> > --- > include/linux/ieee80211.h | 105 > +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 103 insertions(+), 2 deletions(-) > > diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h > index 4a7200c6c9ea..c51d309a45e7 100644 > --- a/include/linux/ieee80211.h > +++ b/include/linux/ieee80211.h > @@ -1457,13 +1457,16 @@ 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; > @@ -1472,6 +1475,13 @@ 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 > @@ -1547,6 +1557,7 @@ struct ieee80211_vht_operation { > #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 > @@ -1575,6 +1586,96 @@ struct ieee80211_vht_operation { > #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 > + > +static int __maybe_unused > +ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap, > + enum ieee80211_vht_chanwidth bw, > + int mcs) > +{ > + u16 map = le16_to_cpu(cap->supp_mcs.rx_mcs_map); > + int max_vht_nss; > + int ext_nss_bw; > + int supp_width; > + int i, mcs_encoding; > + > + if (map == 0xffff) > + return 0; > + > + if (WARN_ON(mcs > 9)) > + return 0; > + if (mcs <= 7) > + mcs_encoding = 0; > + else if (mcs == 8) > + mcs_encoding = 1; > + else > + mcs_encoding = 2; > + > + /* find max_vht_nss for the given MCS */ > + for (i = 7; i >= 0; i--) { > + int supp = (map >> (2*i)) & 3; > + > + if (supp == 3) > + continue; > + > + if (supp >= mcs_encoding) { > + max_vht_nss = i; > + break; > + } > + } > + > + if (!(cap->supp_mcs.tx_mcs_map & > cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE))) > + return max_vht_nss; > + > + ext_nss_bw = (le32_to_cpu(cap->vht_cap_info) & > + IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) > + >> IEEE80211_VHT_CAP_EXT_NSS_BW_SHIFT; > + supp_width = (le32_to_cpu(cap->vht_cap_info) & > + IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) > + >> IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_SHIFT; > + > + /* > + * Cover all the special cases according to IEEE 802.11-2016 Table > 9-250. > + * All other cases are either factor of 1 or not valid/supported. > + */ > + switch (bw) { > + case IEEE80211_VHT_CHANWIDTH_USE_HT: > + case IEEE80211_VHT_CHANWIDTH_80MHZ: > + if ((supp_width == 1 || supp_width == 2) && > + ext_nss_bw == 3) > + return 2 * max_vht_nss; > + break; > + case IEEE80211_VHT_CHANWIDTH_160MHZ: > + if (supp_width == 0 && > + (ext_nss_bw == 1 || ext_nss_bw == 2)) > + return DIV_ROUND_UP(max_vht_nss, 2); > + if (supp_width == 0 && > + ext_nss_bw == 3) > + return DIV_ROUND_UP(3 * max_vht_nss, 4); > + if (supp_width == 1 && > + ext_nss_bw == 3) > + return 2 * max_vht_nss; > + break; > + case IEEE80211_VHT_CHANWIDTH_80P80MHZ: > + if (supp_width == 0 && > + ext_nss_bw == 2) > + return DIV_ROUND_UP(max_vht_nss, 2); > + if (supp_width == 0 && > + ext_nss_bw == 3) > + return DIV_ROUND_UP(3 * max_vht_nss, 4); > + if (supp_width == 1 && > + ext_nss_bw == 1) > + return DIV_ROUND_UP(max_vht_nss, 2); > + if (supp_width == 1 && > + ext_nss_bw == 2) > + return DIV_ROUND_UP(3 * max_vht_nss, 4); > + break; > + }
Looks good to me. > + /* not covered or invalid combination received */ Do you want to inform about the invalid/reserved combination. Regards, Arend > + return max_vht_nss; > +} > > /* Authentication algorithms */ > #define WLAN_AUTH_OPEN 0 >
