tx.c revision 00d201001bd4e8a46e3d03c970abcb72256c368b
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/kernel.h> 25#include <linux/module.h> 26 27#include "wl12xx.h" 28#include "io.h" 29#include "reg.h" 30#include "ps.h" 31#include "tx.h" 32 33static int wl1271_alloc_tx_id(struct wl1271 *wl, struct sk_buff *skb) 34{ 35 int id; 36 37 id = find_first_zero_bit(wl->tx_frames_map, ACX_TX_DESCRIPTORS); 38 if (id >= ACX_TX_DESCRIPTORS) 39 return -EBUSY; 40 41 __set_bit(id, wl->tx_frames_map); 42 wl->tx_frames[id] = skb; 43 wl->tx_frames_cnt++; 44 return id; 45} 46 47static void wl1271_free_tx_id(struct wl1271 *wl, int id) 48{ 49 if (__test_and_clear_bit(id, wl->tx_frames_map)) { 50 wl->tx_frames[id] = NULL; 51 wl->tx_frames_cnt--; 52 } 53} 54 55static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra, 56 u32 buf_offset) 57{ 58 struct wl1271_tx_hw_descr *desc; 59 u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra; 60 u32 total_blocks; 61 int id, ret = -EBUSY; 62 63 if (buf_offset + total_len > WL1271_AGGR_BUFFER_SIZE) 64 return -EAGAIN; 65 66 /* allocate free identifier for the packet */ 67 id = wl1271_alloc_tx_id(wl, skb); 68 if (id < 0) 69 return id; 70 71 /* approximate the number of blocks required for this packet 72 in the firmware */ 73 total_blocks = total_len + TX_HW_BLOCK_SIZE - 1; 74 total_blocks = total_blocks / TX_HW_BLOCK_SIZE + TX_HW_BLOCK_SPARE; 75 if (total_blocks <= wl->tx_blocks_available) { 76 desc = (struct wl1271_tx_hw_descr *)skb_push( 77 skb, total_len - skb->len); 78 79 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE; 80 desc->total_mem_blocks = total_blocks; 81 desc->id = id; 82 83 wl->tx_blocks_available -= total_blocks; 84 85 ret = 0; 86 87 wl1271_debug(DEBUG_TX, 88 "tx_allocate: size: %d, blocks: %d, id: %d", 89 total_len, total_blocks, id); 90 } else { 91 wl1271_free_tx_id(wl, id); 92 } 93 94 return ret; 95} 96 97static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb, 98 u32 extra, struct ieee80211_tx_info *control) 99{ 100 struct timespec ts; 101 struct wl1271_tx_hw_descr *desc; 102 int pad, ac; 103 s64 hosttime; 104 u16 tx_attr; 105 106 desc = (struct wl1271_tx_hw_descr *) skb->data; 107 108 /* relocate space for security header */ 109 if (extra) { 110 void *framestart = skb->data + sizeof(*desc); 111 u16 fc = *(u16 *)(framestart + extra); 112 int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc)); 113 memmove(framestart, framestart + extra, hdrlen); 114 } 115 116 /* configure packet life time */ 117 getnstimeofday(&ts); 118 hosttime = (timespec_to_ns(&ts) >> 10); 119 desc->start_time = cpu_to_le32(hosttime - wl->time_offset); 120 desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU); 121 122 /* configure the tx attributes */ 123 tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER; 124 125 /* queue (we use same identifiers for tid's and ac's */ 126 ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb)); 127 desc->tid = ac; 128 129 desc->aid = TX_HW_DEFAULT_AID; 130 desc->reserved = 0; 131 132 /* align the length (and store in terms of words) */ 133 pad = WL1271_TX_ALIGN(skb->len); 134 desc->length = cpu_to_le16(pad >> 2); 135 136 /* calculate number of padding bytes */ 137 pad = pad - skb->len; 138 tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD; 139 140 /* if the packets are destined for AP (have a STA entry) send them 141 with AP rate policies, otherwise use default basic rates */ 142 if (control->control.sta) 143 tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY; 144 145 desc->tx_attr = cpu_to_le16(tx_attr); 146 147 wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad); 148} 149 150/* caller must hold wl->mutex */ 151static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb, 152 u32 buf_offset) 153{ 154 struct ieee80211_tx_info *info; 155 u32 extra = 0; 156 int ret = 0; 157 u8 idx; 158 u32 total_len; 159 160 if (!skb) 161 return -EINVAL; 162 163 info = IEEE80211_SKB_CB(skb); 164 165 if (info->control.hw_key && 166 info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) 167 extra = WL1271_TKIP_IV_SPACE; 168 169 if (info->control.hw_key) { 170 idx = info->control.hw_key->hw_key_idx; 171 172 /* FIXME: do we have to do this if we're not using WEP? */ 173 if (unlikely(wl->default_key != idx)) { 174 ret = wl1271_cmd_set_default_wep_key(wl, idx); 175 if (ret < 0) 176 return ret; 177 wl->default_key = idx; 178 } 179 } 180 181 ret = wl1271_tx_allocate(wl, skb, extra, buf_offset); 182 if (ret < 0) 183 return ret; 184 185 wl1271_tx_fill_hdr(wl, skb, extra, info); 186 187 /* 188 * The length of each packet is stored in terms of words. Thus, we must 189 * pad the skb data to make sure its length is aligned. 190 * The number of padding bytes is computed and set in wl1271_tx_fill_hdr 191 */ 192 total_len = WL1271_TX_ALIGN(skb->len); 193 memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len); 194 memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len); 195 196 return total_len; 197} 198 199u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set) 200{ 201 struct ieee80211_supported_band *band; 202 u32 enabled_rates = 0; 203 int bit; 204 205 band = wl->hw->wiphy->bands[wl->band]; 206 for (bit = 0; bit < band->n_bitrates; bit++) { 207 if (rate_set & 0x1) 208 enabled_rates |= band->bitrates[bit].hw_value; 209 rate_set >>= 1; 210 } 211 212#ifdef CONFIG_WL12XX_HT 213 /* MCS rates indication are on bits 16 - 23 */ 214 rate_set >>= HW_HT_RATES_OFFSET - band->n_bitrates; 215 216 for (bit = 0; bit < 8; bit++) { 217 if (rate_set & 0x1) 218 enabled_rates |= (CONF_HW_BIT_RATE_MCS_0 << bit); 219 rate_set >>= 1; 220 } 221#endif 222 223 return enabled_rates; 224} 225 226static void handle_tx_low_watermark(struct wl1271 *wl) 227{ 228 unsigned long flags; 229 230 if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) && 231 skb_queue_len(&wl->tx_queue) <= WL1271_TX_QUEUE_LOW_WATERMARK) { 232 /* firmware buffer has space, restart queues */ 233 spin_lock_irqsave(&wl->wl_lock, flags); 234 ieee80211_wake_queues(wl->hw); 235 clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags); 236 spin_unlock_irqrestore(&wl->wl_lock, flags); 237 } 238} 239 240void wl1271_tx_work_locked(struct wl1271 *wl) 241{ 242 struct sk_buff *skb; 243 bool woken_up = false; 244 u32 sta_rates = 0; 245 u32 buf_offset = 0; 246 bool sent_packets = false; 247 int ret; 248 249 /* check if the rates supported by the AP have changed */ 250 if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED, 251 &wl->flags))) { 252 unsigned long flags; 253 254 spin_lock_irqsave(&wl->wl_lock, flags); 255 sta_rates = wl->sta_rate_set; 256 spin_unlock_irqrestore(&wl->wl_lock, flags); 257 } 258 259 if (unlikely(wl->state == WL1271_STATE_OFF)) 260 goto out; 261 262 /* if rates have changed, re-configure the rate policy */ 263 if (unlikely(sta_rates)) { 264 ret = wl1271_ps_elp_wakeup(wl, false); 265 if (ret < 0) 266 goto out; 267 woken_up = true; 268 269 wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates); 270 wl1271_acx_rate_policies(wl); 271 } 272 273 while ((skb = skb_dequeue(&wl->tx_queue))) { 274 if (!woken_up) { 275 ret = wl1271_ps_elp_wakeup(wl, false); 276 if (ret < 0) 277 goto out_ack; 278 woken_up = true; 279 } 280 281 ret = wl1271_prepare_tx_frame(wl, skb, buf_offset); 282 if (ret == -EAGAIN) { 283 /* 284 * Aggregation buffer is full. 285 * Flush buffer and try again. 286 */ 287 skb_queue_head(&wl->tx_queue, skb); 288 wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf, 289 buf_offset, true); 290 sent_packets = true; 291 buf_offset = 0; 292 continue; 293 } else if (ret == -EBUSY) { 294 /* 295 * Firmware buffer is full. 296 * Queue back last skb, and stop aggregating. 297 */ 298 skb_queue_head(&wl->tx_queue, skb); 299 /* No work left, avoid scheduling redundant tx work */ 300 set_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags); 301 goto out_ack; 302 } else if (ret < 0) { 303 dev_kfree_skb(skb); 304 goto out_ack; 305 } 306 buf_offset += ret; 307 wl->tx_packets_count++; 308 } 309 310out_ack: 311 if (buf_offset) { 312 wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf, 313 buf_offset, true); 314 sent_packets = true; 315 } 316 if (sent_packets) { 317 /* interrupt the firmware with the new packets */ 318 wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count); 319 handle_tx_low_watermark(wl); 320 } 321 322out: 323 if (woken_up) 324 wl1271_ps_elp_sleep(wl); 325} 326 327void wl1271_tx_work(struct work_struct *work) 328{ 329 struct wl1271 *wl = container_of(work, struct wl1271, tx_work); 330 331 mutex_lock(&wl->mutex); 332 wl1271_tx_work_locked(wl); 333 mutex_unlock(&wl->mutex); 334} 335 336static void wl1271_tx_complete_packet(struct wl1271 *wl, 337 struct wl1271_tx_hw_res_descr *result) 338{ 339 struct ieee80211_tx_info *info; 340 struct sk_buff *skb; 341 int id = result->id; 342 int rate = -1; 343 u8 retries = 0; 344 345 /* check for id legality */ 346 if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) { 347 wl1271_warning("TX result illegal id: %d", id); 348 return; 349 } 350 351 skb = wl->tx_frames[id]; 352 info = IEEE80211_SKB_CB(skb); 353 354 /* update the TX status info */ 355 if (result->status == TX_SUCCESS) { 356 if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) 357 info->flags |= IEEE80211_TX_STAT_ACK; 358 rate = wl1271_rate_to_idx(result->rate_class_index, wl->band); 359 retries = result->ack_failures; 360 } else if (result->status == TX_RETRY_EXCEEDED) { 361 wl->stats.excessive_retries++; 362 retries = result->ack_failures; 363 } 364 365 info->status.rates[0].idx = rate; 366 info->status.rates[0].count = retries; 367 info->status.rates[0].flags = 0; 368 info->status.ack_signal = -1; 369 370 wl->stats.retry_count += result->ack_failures; 371 372 /* update security sequence number */ 373 wl->tx_security_seq += (result->lsb_security_sequence_number - 374 wl->tx_security_last_seq); 375 wl->tx_security_last_seq = result->lsb_security_sequence_number; 376 377 /* remove private header from packet */ 378 skb_pull(skb, sizeof(struct wl1271_tx_hw_descr)); 379 380 /* remove TKIP header space if present */ 381 if (info->control.hw_key && 382 info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) { 383 int hdrlen = ieee80211_get_hdrlen_from_skb(skb); 384 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen); 385 skb_pull(skb, WL1271_TKIP_IV_SPACE); 386 } 387 388 wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x" 389 " status 0x%x", 390 result->id, skb, result->ack_failures, 391 result->rate_class_index, result->status); 392 393 /* return the packet to the stack */ 394 ieee80211_tx_status(wl->hw, skb); 395 wl1271_free_tx_id(wl, result->id); 396} 397 398/* Called upon reception of a TX complete interrupt */ 399void wl1271_tx_complete(struct wl1271 *wl) 400{ 401 struct wl1271_acx_mem_map *memmap = 402 (struct wl1271_acx_mem_map *)wl->target_mem_map; 403 u32 count, fw_counter; 404 u32 i; 405 406 /* read the tx results from the chipset */ 407 wl1271_read(wl, le32_to_cpu(memmap->tx_result), 408 wl->tx_res_if, sizeof(*wl->tx_res_if), false); 409 fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter); 410 411 /* write host counter to chipset (to ack) */ 412 wl1271_write32(wl, le32_to_cpu(memmap->tx_result) + 413 offsetof(struct wl1271_tx_hw_res_if, 414 tx_result_host_counter), fw_counter); 415 416 count = fw_counter - wl->tx_results_count; 417 wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count); 418 419 /* verify that the result buffer is not getting overrun */ 420 if (unlikely(count > TX_HW_RESULT_QUEUE_LEN)) 421 wl1271_warning("TX result overflow from chipset: %d", count); 422 423 /* process the results */ 424 for (i = 0; i < count; i++) { 425 struct wl1271_tx_hw_res_descr *result; 426 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK; 427 428 /* process the packet */ 429 result = &(wl->tx_res_if->tx_results_queue[offset]); 430 wl1271_tx_complete_packet(wl, result); 431 432 wl->tx_results_count++; 433 } 434} 435 436/* caller must hold wl->mutex */ 437void wl1271_tx_reset(struct wl1271 *wl) 438{ 439 int i; 440 struct sk_buff *skb; 441 442 /* TX failure */ 443 while ((skb = skb_dequeue(&wl->tx_queue))) { 444 wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb); 445 ieee80211_tx_status(wl->hw, skb); 446 } 447 448 /* 449 * Make sure the driver is at a consistent state, in case this 450 * function is called from a context other than interface removal. 451 */ 452 handle_tx_low_watermark(wl); 453 454 for (i = 0; i < ACX_TX_DESCRIPTORS; i++) 455 if (wl->tx_frames[i] != NULL) { 456 skb = wl->tx_frames[i]; 457 wl1271_free_tx_id(wl, i); 458 wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb); 459 ieee80211_tx_status(wl->hw, skb); 460 } 461} 462 463#define WL1271_TX_FLUSH_TIMEOUT 500000 464 465/* caller must *NOT* hold wl->mutex */ 466void wl1271_tx_flush(struct wl1271 *wl) 467{ 468 unsigned long timeout; 469 timeout = jiffies + usecs_to_jiffies(WL1271_TX_FLUSH_TIMEOUT); 470 471 while (!time_after(jiffies, timeout)) { 472 mutex_lock(&wl->mutex); 473 wl1271_debug(DEBUG_TX, "flushing tx buffer: %d", 474 wl->tx_frames_cnt); 475 if ((wl->tx_frames_cnt == 0) && 476 skb_queue_empty(&wl->tx_queue)) { 477 mutex_unlock(&wl->mutex); 478 return; 479 } 480 mutex_unlock(&wl->mutex); 481 msleep(1); 482 } 483 484 wl1271_warning("Unable to flush all TX buffers, timed out."); 485} 486