drivers/net/wireless/wl12xx/rx.c

   1 /*
   2  * This file is part of wl1271
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  *
   6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/gfp.h>
  25
  26 #include "wl12xx.h"
  27 #include "acx.h"
  28 #include "reg.h"
  29 #include "rx.h"
  30 #include "io.h"
  31
  32 static u8 wl1271_rx_get_mem_block(struct wl1271_fw_status *status,
  33                                   u32 drv_rx_counter)
  34 {
  35         return le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
  36                 RX_MEM_BLOCK_MASK;
  37 }
  38
  39 static u32 wl1271_rx_get_buf_size(struct wl1271_fw_status *status,
  40                                  u32 drv_rx_counter)
  41 {
  42         return (le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
  43                 RX_BUF_SIZE_MASK) >> RX_BUF_SIZE_SHIFT_DIV;
  44 }
  45
  46 static void wl1271_rx_status(struct wl1271 *wl,
  47                              struct wl1271_rx_descriptor *desc,
  48                              struct ieee80211_rx_status *status,
  49                              u8 beacon)
  50 {
  51         enum ieee80211_band desc_band;
  52
  53         memset(status, 0, sizeof(struct ieee80211_rx_status));
  54
  55         status->band = wl->band;
  56
  57         if ((desc->flags & WL1271_RX_DESC_BAND_MASK) == WL1271_RX_DESC_BAND_BG)
  58                 desc_band = IEEE80211_BAND_2GHZ;
  59         else
  60                 desc_band = IEEE80211_BAND_5GHZ;
  61
  62         status->rate_idx = wl1271_rate_to_idx(desc->rate, desc_band);
  63
  64 #ifdef CONFIG_WL12XX_HT
  65         /* 11n support */
  66         if (desc->rate <= CONF_HW_RXTX_RATE_MCS0)
  67                 status->flag |= RX_FLAG_HT;
  68 #endif
  69
  70         status->signal = desc->rssi;
  71
  72         /*
  73          * FIXME: In wl1251, the SNR should be divided by two.  In wl1271 we
  74          * need to divide by two for now, but TI has been discussing about
  75          * changing it.  This needs to be rechecked.
  76          */
  77         wl->noise = desc->rssi - (desc->snr >> 1);
  78
  79         status->freq = ieee80211_channel_to_frequency(desc->channel);
  80
  81         if (desc->flags & WL1271_RX_DESC_ENCRYPT_MASK) {
  82                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  83
  84                 if (likely(!(desc->status & WL1271_RX_DESC_DECRYPT_FAIL)))
  85                         status->flag |= RX_FLAG_DECRYPTED;
  86                 if (unlikely(desc->status & WL1271_RX_DESC_MIC_FAIL))
  87                         status->flag |= RX_FLAG_MMIC_ERROR;
  88         }
  89 }
  90
  91 static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
  92 {
  93         struct wl1271_rx_descriptor *desc;
  94         struct sk_buff *skb;
  95         u16 *fc;
  96         u8 *buf;
  97         u8 beacon = 0;
  98
  99         /*
 100          * In PLT mode we seem to get frames and mac80211 warns about them,
 101          * workaround this by not retrieving them at all.
 102          */
 103         if (unlikely(wl->state == WL1271_STATE_PLT))
 104                 return -EINVAL;
 105
 106         skb = __dev_alloc_skb(length, GFP_KERNEL);
 107         if (!skb) {
 108                 wl1271_error("Couldn't allocate RX frame");
 109                 return -ENOMEM;
 110         }
 111
 112         buf = skb_put(skb, length);
 113         memcpy(buf, data, length);
 114
 115         /* the data read starts with the descriptor */
 116         desc = (struct wl1271_rx_descriptor *) buf;
 117
 118         /* now we pull the descriptor out of the buffer */
 119         skb_pull(skb, sizeof(*desc));
 120
 121         fc = (u16 *)skb->data;
 122         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 123                 beacon = 1;
 124
 125         wl1271_rx_status(wl, desc, IEEE80211_SKB_RXCB(skb), beacon);
 126
 127         wl1271_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 128                      beacon ? "beacon" : "");
 129
 130         skb_trim(skb, skb->len - desc->pad_len);
 131
 132         ieee80211_rx_ni(wl->hw, skb);
 133
 134         return 0;
 135 }
 136
 137 void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_status *status)
 138 {
 139         struct wl1271_acx_mem_map *wl_mem_map = wl->target_mem_map;
 140         u32 buf_size;
 141         u32 fw_rx_counter  = status->fw_rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
 142         u32 drv_rx_counter = wl->rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
 143         u32 rx_counter;
 144         u32 mem_block;
 145         u32 pkt_length;
 146         u32 pkt_offset;
 147
 148         while (drv_rx_counter != fw_rx_counter) {
 149                 buf_size = 0;
 150                 rx_counter = drv_rx_counter;
 151                 while (rx_counter != fw_rx_counter) {
 152                         pkt_length = wl1271_rx_get_buf_size(status, rx_counter);
 153                         if (buf_size + pkt_length > WL1271_AGGR_BUFFER_SIZE)
 154                                 break;
 155                         buf_size += pkt_length;
 156                         rx_counter++;
 157                         rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
 158                 }
 159
 160                 if (buf_size == 0) {
 161                         wl1271_warning("received empty data");
 162                         break;
 163                 }
 164
 165                 /*
 166                  * Choose the block we want to read
 167                  * For aggregated packets, only the first memory block should
 168                  * be retrieved. The FW takes care of the rest.
 169                  */
 170                 mem_block = wl1271_rx_get_mem_block(status, drv_rx_counter);
 171                 wl->rx_mem_pool_addr.addr = (mem_block << 8) +
 172                         le32_to_cpu(wl_mem_map->packet_memory_pool_start);
 173                 wl->rx_mem_pool_addr.addr_extra =
 174                         wl->rx_mem_pool_addr.addr + 4;
 175                 wl1271_write(wl, WL1271_SLV_REG_DATA, &wl->rx_mem_pool_addr,
 176                                 sizeof(wl->rx_mem_pool_addr), false);
 177
 178                 /* Read all available packets at once */
 179                 wl1271_read(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
 180                                 buf_size, true);
 181
 182                 /* Split data into separate packets */
 183                 pkt_offset = 0;
 184                 while (pkt_offset < buf_size) {
 185                         pkt_length = wl1271_rx_get_buf_size(status,
 186                                         drv_rx_counter);
 187                         /*
 188                          * the handle data call can only fail in memory-outage
 189                          * conditions, in that case the received frame will just
 190                          * be dropped.
 191                          */
 192                         wl1271_rx_handle_data(wl,
 193                                               wl->aggr_buf + pkt_offset,
 194                                               pkt_length);
 195                         wl->rx_counter++;
 196                         drv_rx_counter++;
 197                         drv_rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
 198                         pkt_offset += pkt_length;
 199                 }
 200         }
 201         wl1271_write32(wl, RX_DRIVER_COUNTER_ADDRESS,
 202                         cpu_to_le32(wl->rx_counter));
 203 }