diff options
Diffstat (limited to 'drivers/net/wireless/iwlwifi/mvm/rx.c')
| -rw-r--r-- | drivers/net/wireless/iwlwifi/mvm/rx.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/drivers/net/wireless/iwlwifi/mvm/rx.c b/drivers/net/wireless/iwlwifi/mvm/rx.c new file mode 100644 index 000000000000..3f40ab05bbd8 --- /dev/null +++ b/drivers/net/wireless/iwlwifi/mvm/rx.c @@ -0,0 +1,356 @@ +/****************************************************************************** + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, + * USA + * + * The full GNU General Public License is included in this distribution + * in the file called LICENSE.GPL. + * + * Contact Information: + * Intel Linux Wireless <ilw@linux.intel.com> + * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 + * + * BSD LICENSE + * + * Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + *****************************************************************************/ +#include "iwl-trans.h" + +#include "mvm.h" +#include "fw-api.h" + +/* + * iwl_mvm_rx_rx_phy_cmd - REPLY_RX_PHY_CMD handler + * + * Copies the phy information in mvm->last_phy_info, it will be used when the + * actual data will come from the fw in the next packet. + */ +int iwl_mvm_rx_rx_phy_cmd(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb, + struct iwl_device_cmd *cmd) +{ + struct iwl_rx_packet *pkt = rxb_addr(rxb); + + memcpy(&mvm->last_phy_info, pkt->data, sizeof(mvm->last_phy_info)); + mvm->ampdu_ref++; + return 0; +} + +/* + * iwl_mvm_pass_packet_to_mac80211 - builds the packet for mac80211 + * + * Adds the rxb to a new skb and give it to mac80211 + */ +static void iwl_mvm_pass_packet_to_mac80211(struct iwl_mvm *mvm, + struct ieee80211_hdr *hdr, u16 len, + u32 ampdu_status, + struct iwl_rx_cmd_buffer *rxb, + struct ieee80211_rx_status *stats) +{ + struct sk_buff *skb; + unsigned int hdrlen, fraglen; + + /* Dont use dev_alloc_skb(), we'll have enough headroom once + * ieee80211_hdr pulled. + */ + skb = alloc_skb(128, GFP_ATOMIC); + if (!skb) { + IWL_ERR(mvm, "alloc_skb failed\n"); + return; + } + /* If frame is small enough to fit in skb->head, pull it completely. + * If not, only pull ieee80211_hdr so that splice() or TCP coalesce + * are more efficient. + */ + hdrlen = (len <= skb_tailroom(skb)) ? len : sizeof(*hdr); + + memcpy(skb_put(skb, hdrlen), hdr, hdrlen); + fraglen = len - hdrlen; + + if (fraglen) { + int offset = (void *)hdr + hdrlen - + rxb_addr(rxb) + rxb_offset(rxb); + + skb_add_rx_frag(skb, 0, rxb_steal_page(rxb), offset, + fraglen, rxb->truesize); + } + + memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats)); + + ieee80211_rx_ni(mvm->hw, skb); +} + +/* + * iwl_mvm_calc_rssi - calculate the rssi in dBm + * @phy_info: the phy information for the coming packet + */ +static int iwl_mvm_calc_rssi(struct iwl_mvm *mvm, + struct iwl_rx_phy_info *phy_info) +{ + u32 rssi_a, rssi_b, rssi_c, max_rssi, agc_db; + u32 val; + + /* Find max rssi among 3 possible receivers. + * These values are measured by the Digital Signal Processor (DSP). + * They should stay fairly constant even as the signal strength varies, + * if the radio's Automatic Gain Control (AGC) is working right. + * AGC value (see below) will provide the "interesting" info. + */ + val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_RSSI_AB_IDX]); + rssi_a = (val & IWL_OFDM_RSSI_INBAND_A_MSK) >> IWL_OFDM_RSSI_A_POS; + rssi_b = (val & IWL_OFDM_RSSI_INBAND_B_MSK) >> IWL_OFDM_RSSI_B_POS; + val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_RSSI_C_IDX]); + rssi_c = (val & IWL_OFDM_RSSI_INBAND_C_MSK) >> IWL_OFDM_RSSI_C_POS; + + val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_AGC_IDX]); + agc_db = (val & IWL_OFDM_AGC_DB_MSK) >> IWL_OFDM_AGC_DB_POS; + + max_rssi = max_t(u32, rssi_a, rssi_b); + max_rssi = max_t(u32, max_rssi, rssi_c); + + IWL_DEBUG_STATS(mvm, "Rssi In A %d B %d C %d Max %d AGC dB %d\n", + rssi_a, rssi_b, rssi_c, max_rssi, agc_db); + + /* dBm = max_rssi dB - agc dB - constant. + * Higher AGC (higher radio gain) means lower signal. */ + return max_rssi - agc_db - IWL_RSSI_OFFSET; +} + +/* + * iwl_mvm_set_mac80211_rx_flag - translate fw status to mac80211 format + * @mvm: the mvm object + * @hdr: 80211 header + * @stats: status in mac80211's format + * @rx_pkt_status: status coming from fw + * + * returns non 0 value if the packet should be dropped + */ +static u32 iwl_mvm_set_mac80211_rx_flag(struct iwl_mvm *mvm, + struct ieee80211_hdr *hdr, + struct ieee80211_rx_status *stats, + u32 rx_pkt_status) +{ + if (!ieee80211_has_protected(hdr->frame_control) || + (rx_pkt_status & RX_MPDU_RES_STATUS_SEC_ENC_MSK) == + RX_MPDU_RES_STATUS_SEC_NO_ENC) + return 0; + + /* packet was encrypted with unknown alg */ + if ((rx_pkt_status & RX_MPDU_RES_STATUS_SEC_ENC_MSK) == + RX_MPDU_RES_STATUS_SEC_ENC_ERR) + return 0; + + switch (rx_pkt_status & RX_MPDU_RES_STATUS_SEC_ENC_MSK) { + case RX_MPDU_RES_STATUS_SEC_CCM_ENC: + /* alg is CCM: check MIC only */ + if (!(rx_pkt_status & RX_MPDU_RES_STATUS_MIC_OK)) + return -1; + + stats->flag |= RX_FLAG_DECRYPTED; + IWL_DEBUG_WEP(mvm, "hw decrypted CCMP successfully\n"); + return 0; + + case RX_MPDU_RES_STATUS_SEC_TKIP_ENC: + /* Don't drop the frame and decrypt it in SW */ + if (!(rx_pkt_status & RX_MPDU_RES_STATUS_TTAK_OK)) + return 0; + /* fall through if TTAK OK */ + + case RX_MPDU_RES_STATUS_SEC_WEP_ENC: + if (!(rx_pkt_status & RX_MPDU_RES_STATUS_ICV_OK)) + return -1; + + stats->flag |= RX_FLAG_DECRYPTED; + return 0; + + default: + IWL_ERR(mvm, "Unhandled alg: 0x%x\n", rx_pkt_status); + } + + return 0; +} + +/* + * iwl_mvm_rx_rx_mpdu - REPLY_RX_MPDU_CMD handler + * + * Handles the actual data of the Rx packet from the fw + */ +int iwl_mvm_rx_rx_mpdu(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb, + struct iwl_device_cmd *cmd) +{ + struct ieee80211_hdr *hdr; + struct ieee80211_rx_status rx_status = {}; + struct iwl_rx_packet *pkt = rxb_addr(rxb); + struct iwl_rx_phy_info *phy_info; + struct iwl_rx_mpdu_res_start *rx_res; + u32 len; + u32 ampdu_status; + u32 rate_n_flags; + u32 rx_pkt_status; + + phy_info = &mvm->last_phy_info; + rx_res = (struct iwl_rx_mpdu_res_start *)pkt->data; + hdr = (struct ieee80211_hdr *)(pkt->data + sizeof(*rx_res)); + len = le16_to_cpu(rx_res->byte_count); + rx_pkt_status = le32_to_cpup((__le32 *) + (pkt->data + sizeof(*rx_res) + len)); + + memset(&rx_status, 0, sizeof(rx_status)); + + /* + * drop the packet if it has failed being decrypted by HW + */ + if (iwl_mvm_set_mac80211_rx_flag(mvm, hdr, &rx_status, rx_pkt_status)) { + IWL_DEBUG_DROP(mvm, "Bad decryption results 0x%08x\n", + rx_pkt_status); + return 0; + } + + if ((unlikely(phy_info->cfg_phy_cnt > 20))) { + IWL_DEBUG_DROP(mvm, "dsp size out of range [0,20]: %d\n", + phy_info->cfg_phy_cnt); + return 0; + } + + if (!(rx_pkt_status & RX_MPDU_RES_STATUS_CRC_OK) || + !(rx_pkt_status & RX_MPDU_RES_STATUS_OVERRUN_OK)) { + IWL_DEBUG_RX(mvm, "Bad CRC or FIFO: 0x%08X.\n", rx_pkt_status); + return 0; + } + + /* This will be used in several places later */ + rate_n_flags = le32_to_cpu(phy_info->rate_n_flags); + + /* rx_status carries information about the packet to mac80211 */ + rx_status.mactime = le64_to_cpu(phy_info->timestamp); + rx_status.device_timestamp = le32_to_cpu(phy_info->system_timestamp); + rx_status.band = + (phy_info->phy_flags & cpu_to_le16(RX_RES_PHY_FLAGS_BAND_24)) ? + IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ; + rx_status.freq = + ieee80211_channel_to_frequency(le16_to_cpu(phy_info->channel), + rx_status.band); + /* + * TSF as indicated by the fw is at INA time, but mac80211 expects the + * TSF at the beginning of the MPDU. + */ + /*rx_status.flag |= RX_FLAG_MACTIME_MPDU;*/ + + /* Find max signal strength (dBm) among 3 antenna/receiver chains */ + rx_status.signal = iwl_mvm_calc_rssi(mvm, phy_info); + + IWL_DEBUG_STATS_LIMIT(mvm, "Rssi %d, TSF %llu\n", rx_status.signal, + (unsigned long long)rx_status.mactime); + + /* + * "antenna number" + * + * It seems that the antenna field in the phy flags value + * is actually a bit field. This is undefined by radiotap, + * it wants an actual antenna number but I always get "7" + * for most legacy frames I receive indicating that the + * same frame was received on all three RX chains. + * + * I think this field should be removed in favor of a + * new 802.11n radiotap field "RX chains" that is defined + * as a bitmask. + */ + rx_status.antenna = (le16_to_cpu(phy_info->phy_flags) & + RX_RES_PHY_FLAGS_ANTENNA) + >> RX_RES_PHY_FLAGS_ANTENNA_POS; + + /* set the preamble flag if appropriate */ + if (phy_info->phy_flags & cpu_to_le16(RX_RES_PHY_FLAGS_SHORT_PREAMBLE)) + rx_status.flag |= RX_FLAG_SHORTPRE; + + if (phy_info->phy_flags & cpu_to_le16(RX_RES_PHY_FLAGS_AGG)) { + /* + * We know which subframes of an A-MPDU belong + * together since we get a single PHY response + * from the firmware for all of them + */ + rx_status.flag |= RX_FLAG_AMPDU_DETAILS; + rx_status.ampdu_reference = mvm->ampdu_ref; + } + + /* Set up the HT phy flags */ + switch (rate_n_flags & RATE_MCS_CHAN_WIDTH_MSK) { + case RATE_MCS_CHAN_WIDTH_20: + break; + case RATE_MCS_CHAN_WIDTH_40: + rx_status.flag |= RX_FLAG_40MHZ; + break; + case RATE_MCS_CHAN_WIDTH_80: + rx_status.flag |= RX_FLAG_80MHZ; + break; + case RATE_MCS_CHAN_WIDTH_160: + rx_status.flag |= RX_FLAG_160MHZ; + break; + } + if (rate_n_flags & RATE_MCS_SGI_MSK) + rx_status.flag |= RX_FLAG_SHORT_GI; + if (rate_n_flags & RATE_HT_MCS_GF_MSK) + rx_status.flag |= RX_FLAG_HT_GF; + if (rate_n_flags & RATE_MCS_HT_MSK) { + rx_status.flag |= RX_FLAG_HT; + rx_status.rate_idx = rate_n_flags & RATE_HT_MCS_INDEX_MSK; + } else if (rate_n_flags & RATE_MCS_VHT_MSK) { + rx_status.vht_nss = + ((rate_n_flags & RATE_VHT_MCS_NSS_MSK) >> + RATE_VHT_MCS_NSS_POS) + 1; + rx_status.rate_idx = rate_n_flags & RATE_VHT_MCS_RATE_CODE_MSK; + rx_status.flag |= RX_FLAG_VHT; + } else { + rx_status.rate_idx = + iwl_mvm_legacy_rate_to_mac80211_idx(rate_n_flags, + rx_status.band); + } + + iwl_mvm_pass_packet_to_mac80211(mvm, hdr, len, ampdu_status, + rxb, &rx_status); + return 0; +} |