drivers/net/wireless/wl12xx/wl1271_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 "wl1271.h"
  27 #include "wl1271_acx.h"
  28 #include "wl1271_reg.h"
  29 #include "wl1271_rx.h"
  30 #include "wl1271_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         memset(status, 0, sizeof(struct ieee80211_rx_status));
  52
  53         status->band = wl->band;
  54         status->rate_idx = wl1271_rate_to_idx(wl, desc->rate);
  55
  56         status->signal = desc->rssi;
  57
  58         /*
  59          * FIXME: In wl1251, the SNR should be divided by two.  In wl1271 we
  60          * need to divide by two for now, but TI has been discussing about
  61          * changing it.  This needs to be rechecked.
  62          */
  63         wl->noise = desc->rssi - (desc->snr >> 1);
  64
  65         status->freq = ieee80211_channel_to_frequency(desc->channel);
  66
  67         if (desc->flags & WL1271_RX_DESC_ENCRYPT_MASK) {
  68                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  69
  70                 if (likely(!(desc->status & WL1271_RX_DESC_DECRYPT_FAIL)))
  71                         status->flag |= RX_FLAG_DECRYPTED;
  72                 if (unlikely(desc->status & WL1271_RX_DESC_MIC_FAIL))
  73                         status->flag |= RX_FLAG_MMIC_ERROR;
  74         }
  75 }
  76
  77 static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
  78 {
  79         struct wl1271_rx_descriptor *desc;
  80         struct sk_buff *skb;
  81         u16 *fc;
  82         u8 *buf;
  83         u8 beacon = 0;
  84
  85         /*
  86          * In PLT mode we seem to get frames and mac80211 warns about them,
  87          * workaround this by not retrieving them at all.
  88          */
  89         if (unlikely(wl->state == WL1271_STATE_PLT))
  90                 return -EINVAL;
  91
  92         skb = __dev_alloc_skb(length, GFP_KERNEL);
  93         if (!skb) {
  94                 wl1271_error("Couldn't allocate RX frame");
  95                 return -ENOMEM;
  96         }
  97
  98         buf = skb_put(skb, length);
  99         memcpy(buf, data, length);
 100
 101         /* the data read starts with the descriptor */
 102         desc = (struct wl1271_rx_descriptor *) buf;
 103
 104         /* now we pull the descriptor out of the buffer */
 105         skb_pull(skb, sizeof(*desc));
 106
 107         fc = (u16 *)skb->data;
 108         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 109                 beacon = 1;
 110
 111         wl1271_rx_status(wl, desc, IEEE80211_SKB_RXCB(skb), beacon);
 112
 113         wl1271_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 114                      beacon ? "beacon" : "");
 115
 116         skb_trim(skb, skb->len - desc->pad_len);
 117
 118         ieee80211_rx_ni(wl->hw, skb);
 119
 120         return 0;
 121 }
 122
 123 void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_status *status)
 124 {
 125         struct wl1271_acx_mem_map *wl_mem_map = wl->target_mem_map;
 126         u32 buf_size;
 127         u32 fw_rx_counter  = status->fw_rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
 128         u32 drv_rx_counter = wl->rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
 129         u32 rx_counter;
 130         u32 mem_block;
 131         u32 pkt_length;
 132         u32 pkt_offset;
 133
 134         while (drv_rx_counter != fw_rx_counter) {
 135                 buf_size = 0;
 136                 rx_counter = drv_rx_counter;
 137                 while (rx_counter != fw_rx_counter) {
 138                         pkt_length = wl1271_rx_get_buf_size(status, rx_counter);
 139                         if (buf_size + pkt_length > WL1271_AGGR_BUFFER_SIZE)
 140                                 break;
 141                         buf_size += pkt_length;
 142                         rx_counter++;
 143                         rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
 144                 }
 145
 146                 if (buf_size == 0) {
 147                         wl1271_warning("received empty data");
 148                         break;
 149                 }
 150
 151                 /*
 152                  * Choose the block we want to read
 153                  * For aggregated packets, only the first memory block should
 154                  * be retrieved. The FW takes care of the rest.
 155                  */
 156                 mem_block = wl1271_rx_get_mem_block(status, drv_rx_counter);
 157                 wl->rx_mem_pool_addr.addr = (mem_block << 8) +
 158                         le32_to_cpu(wl_mem_map->packet_memory_pool_start);
 159                 wl->rx_mem_pool_addr.addr_extra =
 160                         wl->rx_mem_pool_addr.addr + 4;
 161                 wl1271_write(wl, WL1271_SLV_REG_DATA, &wl->rx_mem_pool_addr,
 162                                 sizeof(wl->rx_mem_pool_addr), false);
 163
 164                 /* Read all available packets at once */
 165                 wl1271_read(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
 166                                 buf_size, true);
 167
 168                 /* Split data into separate packets */
 169                 pkt_offset = 0;
 170                 while (pkt_offset < buf_size) {
 171                         pkt_length = wl1271_rx_get_buf_size(status,
 172                                         drv_rx_counter);
 173                         if (wl1271_rx_handle_data(wl,
 174                                         wl->aggr_buf + pkt_offset,
 175                                         pkt_length) < 0)
 176                                 break;
 177                         wl->rx_counter++;
 178                         drv_rx_counter++;
 179                         drv_rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
 180                         pkt_offset += pkt_length;
 181                 }
 182         }
 183         wl1271_write32(wl, RX_DRIVER_COUNTER_ADDRESS,
 184                         cpu_to_le32(wl->rx_counter));
 185 }