drivers/net/wireless/ti/wl1251/rx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * This file is part of wl1251
   4  *
   5  * Copyright (c) 1998-2007 Texas Instruments Incorporated
   6  * Copyright (C) 2008 Nokia Corporation
   7  */
   8
   9 #include <linux/skbuff.h>
  10 #include <linux/gfp.h>
  11 #include <net/mac80211.h>
  12
  13 #include "wl1251.h"
  14 #include "reg.h"
  15 #include "io.h"
  16 #include "rx.h"
  17 #include "cmd.h"
  18 #include "acx.h"
  19
  20 static void wl1251_rx_header(struct wl1251 *wl,
  21                              struct wl1251_rx_descriptor *desc)
  22 {
  23         u32 rx_packet_ring_addr;
  24
  25         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
  26         if (wl->rx_current_buffer)
  27                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
  28
  29         wl1251_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
  30 }
  31
  32 static void wl1251_rx_status(struct wl1251 *wl,
  33                              struct wl1251_rx_descriptor *desc,
  34                              struct ieee80211_rx_status *status,
  35                              u8 beacon)
  36 {
  37         u64 mactime;
  38         int ret;
  39
  40         memset(status, 0, sizeof(struct ieee80211_rx_status));
  41
  42         status->band = NL80211_BAND_2GHZ;
  43         status->mactime = desc->timestamp;
  44
  45         /*
  46          * The rx status timestamp is a 32 bits value while the TSF is a
  47          * 64 bits one.
  48          * For IBSS merging, TSF is mandatory, so we have to get it
  49          * somehow, so we ask for ACX_TSF_INFO.
  50          * That could be moved to the get_tsf() hook, but unfortunately,
  51          * this one must be atomic, while our SPI routines can sleep.
  52          */
  53         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  54                 ret = wl1251_acx_tsf_info(wl, &mactime);
  55                 if (ret == 0)
  56                         status->mactime = mactime;
  57         }
  58
  59         status->signal = desc->rssi;
  60
  61         /*
  62          * FIXME: guessing that snr needs to be divided by two, otherwise
  63          * the values don't make any sense
  64          */
  65         wl->noise = desc->rssi - desc->snr / 2;
  66
  67         status->freq = ieee80211_channel_to_frequency(desc->channel,
  68                                                       status->band);
  69
  70         status->flag |= RX_FLAG_MACTIME_START;
  71
  72         if (!wl->monitor_present && (desc->flags & RX_DESC_ENCRYPTION_MASK)) {
  73                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  74
  75                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
  76                         status->flag |= RX_FLAG_DECRYPTED;
  77
  78                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
  79                         status->flag |= RX_FLAG_MMIC_ERROR;
  80         }
  81
  82         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
  83                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
  84
  85         switch (desc->rate) {
  86                 /* skip 1 and 12 Mbps because they have same value 0x0a */
  87         case RATE_2MBPS:
  88                 status->rate_idx = 1;
  89                 break;
  90         case RATE_5_5MBPS:
  91                 status->rate_idx = 2;
  92                 break;
  93         case RATE_11MBPS:
  94                 status->rate_idx = 3;
  95                 break;
  96         case RATE_6MBPS:
  97                 status->rate_idx = 4;
  98                 break;
  99         case RATE_9MBPS:
 100                 status->rate_idx = 5;
 101                 break;
 102         case RATE_18MBPS:
 103                 status->rate_idx = 7;
 104                 break;
 105         case RATE_24MBPS:
 106                 status->rate_idx = 8;
 107                 break;
 108         case RATE_36MBPS:
 109                 status->rate_idx = 9;
 110                 break;
 111         case RATE_48MBPS:
 112                 status->rate_idx = 10;
 113                 break;
 114         case RATE_54MBPS:
 115                 status->rate_idx = 11;
 116                 break;
 117         }
 118
 119         /* for 1 and 12 Mbps we have to check the modulation */
 120         if (desc->rate == RATE_1MBPS) {
 121                 if (!(desc->mod_pre & OFDM_RATE_BIT))
 122                         /* CCK -> RATE_1MBPS */
 123                         status->rate_idx = 0;
 124                 else
 125                         /* OFDM -> RATE_12MBPS */
 126                         status->rate_idx = 6;
 127         }
 128
 129         if (desc->mod_pre & SHORT_PREAMBLE_BIT)
 130                 status->enc_flags |= RX_ENC_FLAG_SHORTPRE;
 131 }
 132
 133 static void wl1251_rx_body(struct wl1251 *wl,
 134                            struct wl1251_rx_descriptor *desc)
 135 {
 136         struct sk_buff *skb;
 137         struct ieee80211_rx_status status;
 138         u8 *rx_buffer, beacon = 0;
 139         u16 length, *fc;
 140         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 141
 142         length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 143         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 144         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 145
 146         if (last_id_inc != curr_id) {
 147                 wl1251_warning("curr ID:%d, last ID inc:%d",
 148                                curr_id, last_id_inc);
 149                 wl->rx_last_id = curr_id;
 150         } else {
 151                 wl->rx_last_id = last_id_inc;
 152         }
 153
 154         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 155                 sizeof(struct wl1251_rx_descriptor) + 20;
 156         if (wl->rx_current_buffer)
 157                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 158
 159         skb = __dev_alloc_skb(length, GFP_KERNEL);
 160         if (!skb) {
 161                 wl1251_error("Couldn't allocate RX frame");
 162                 return;
 163         }
 164
 165         rx_buffer = skb_put(skb, length);
 166         wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 167
 168         /* The actual length doesn't include the target's alignment */
 169         skb_trim(skb, desc->length - PLCP_HEADER_LENGTH);
 170
 171         fc = (u16 *)skb->data;
 172
 173         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 174                 beacon = 1;
 175
 176         wl1251_rx_status(wl, desc, &status, beacon);
 177
 178         wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 179                      beacon ? "beacon" : "");
 180
 181         memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
 182         ieee80211_rx_ni(wl->hw, skb);
 183 }
 184
 185 static void wl1251_rx_ack(struct wl1251 *wl)
 186 {
 187         u32 data, addr;
 188
 189         if (wl->rx_current_buffer) {
 190                 addr = ACX_REG_INTERRUPT_TRIG_H;
 191                 data = INTR_TRIG_RX_PROC1;
 192         } else {
 193                 addr = ACX_REG_INTERRUPT_TRIG;
 194                 data = INTR_TRIG_RX_PROC0;
 195         }
 196
 197         wl1251_reg_write32(wl, addr, data);
 198
 199         /* Toggle buffer ring */
 200         wl->rx_current_buffer = !wl->rx_current_buffer;
 201 }
 202
 203
 204 void wl1251_rx(struct wl1251 *wl)
 205 {
 206         struct wl1251_rx_descriptor *rx_desc;
 207
 208         if (wl->state != WL1251_STATE_ON)
 209                 return;
 210
 211         rx_desc = wl->rx_descriptor;
 212
 213         /* We first read the frame's header */
 214         wl1251_rx_header(wl, rx_desc);
 215
 216         /* Now we can read the body */
 217         wl1251_rx_body(wl, rx_desc);
 218
 219         /* Finally, we need to ACK the RX */
 220         wl1251_rx_ack(wl);
 221 }