diff options
Diffstat (limited to 'drivers/net/wireless/wl12xx/tx.c')
| -rw-r--r-- | drivers/net/wireless/wl12xx/tx.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c new file mode 100644 index 000000000000..d332b3f6d0fa --- /dev/null +++ b/drivers/net/wireless/wl12xx/tx.c @@ -0,0 +1,485 @@ +/* + * This file is part of wl1271 + * + * Copyright (C) 2009 Nokia Corporation + * + * Contact: Luciano Coelho <luciano.coelho@nokia.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 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 St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> + +#include "wl12xx.h" +#include "io.h" +#include "reg.h" +#include "ps.h" +#include "tx.h" + +static int wl1271_alloc_tx_id(struct wl1271 *wl, struct sk_buff *skb) +{ + int id; + + id = find_first_zero_bit(wl->tx_frames_map, ACX_TX_DESCRIPTORS); + if (id >= ACX_TX_DESCRIPTORS) + return -EBUSY; + + __set_bit(id, wl->tx_frames_map); + wl->tx_frames[id] = skb; + wl->tx_frames_cnt++; + return id; +} + +static void wl1271_free_tx_id(struct wl1271 *wl, int id) +{ + if (__test_and_clear_bit(id, wl->tx_frames_map)) { + wl->tx_frames[id] = NULL; + wl->tx_frames_cnt--; + } +} + +static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra, + u32 buf_offset) +{ + struct wl1271_tx_hw_descr *desc; + u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra; + u32 total_blocks; + int id, ret = -EBUSY; + + if (buf_offset + total_len > WL1271_AGGR_BUFFER_SIZE) + return -EAGAIN; + + /* allocate free identifier for the packet */ + id = wl1271_alloc_tx_id(wl, skb); + if (id < 0) + return id; + + /* approximate the number of blocks required for this packet + in the firmware */ + total_blocks = total_len + TX_HW_BLOCK_SIZE - 1; + total_blocks = total_blocks / TX_HW_BLOCK_SIZE + TX_HW_BLOCK_SPARE; + if (total_blocks <= wl->tx_blocks_available) { + desc = (struct wl1271_tx_hw_descr *)skb_push( + skb, total_len - skb->len); + + desc->extra_mem_blocks = TX_HW_BLOCK_SPARE; + desc->total_mem_blocks = total_blocks; + desc->id = id; + + wl->tx_blocks_available -= total_blocks; + + ret = 0; + + wl1271_debug(DEBUG_TX, + "tx_allocate: size: %d, blocks: %d, id: %d", + total_len, total_blocks, id); + } else { + wl1271_free_tx_id(wl, id); + } + + return ret; +} + +static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb, + u32 extra, struct ieee80211_tx_info *control) +{ + struct timespec ts; + struct wl1271_tx_hw_descr *desc; + int pad, ac; + s64 hosttime; + u16 tx_attr; + + desc = (struct wl1271_tx_hw_descr *) skb->data; + + /* relocate space for security header */ + if (extra) { + void *framestart = skb->data + sizeof(*desc); + u16 fc = *(u16 *)(framestart + extra); + int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc)); + memmove(framestart, framestart + extra, hdrlen); + } + + /* configure packet life time */ + getnstimeofday(&ts); + hosttime = (timespec_to_ns(&ts) >> 10); + desc->start_time = cpu_to_le32(hosttime - wl->time_offset); + desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU); + + /* configure the tx attributes */ + tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER; + + /* queue (we use same identifiers for tid's and ac's */ + ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb)); + desc->tid = ac; + + desc->aid = TX_HW_DEFAULT_AID; + desc->reserved = 0; + + /* align the length (and store in terms of words) */ + pad = WL1271_TX_ALIGN(skb->len); + desc->length = cpu_to_le16(pad >> 2); + + /* calculate number of padding bytes */ + pad = pad - skb->len; + tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD; + + /* if the packets are destined for AP (have a STA entry) send them + with AP rate policies, otherwise use default basic rates */ + if (control->control.sta) + tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY; + + desc->tx_attr = cpu_to_le16(tx_attr); + + wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad); +} + +/* caller must hold wl->mutex */ +static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb, + u32 buf_offset) +{ + struct ieee80211_tx_info *info; + u32 extra = 0; + int ret = 0; + u8 idx; + u32 total_len; + + if (!skb) + return -EINVAL; + + info = IEEE80211_SKB_CB(skb); + + if (info->control.hw_key && + info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) + extra = WL1271_TKIP_IV_SPACE; + + if (info->control.hw_key) { + idx = info->control.hw_key->hw_key_idx; + + /* FIXME: do we have to do this if we're not using WEP? */ + if (unlikely(wl->default_key != idx)) { + ret = wl1271_cmd_set_default_wep_key(wl, idx); + if (ret < 0) + return ret; + wl->default_key = idx; + } + } + + ret = wl1271_tx_allocate(wl, skb, extra, buf_offset); + if (ret < 0) + return ret; + + wl1271_tx_fill_hdr(wl, skb, extra, info); + + /* + * The length of each packet is stored in terms of words. Thus, we must + * pad the skb data to make sure its length is aligned. + * The number of padding bytes is computed and set in wl1271_tx_fill_hdr + */ + total_len = WL1271_TX_ALIGN(skb->len); + memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len); + memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len); + + return total_len; +} + +u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set) +{ + struct ieee80211_supported_band *band; + u32 enabled_rates = 0; + int bit; + + band = wl->hw->wiphy->bands[wl->band]; + for (bit = 0; bit < band->n_bitrates; bit++) { + if (rate_set & 0x1) + enabled_rates |= band->bitrates[bit].hw_value; + rate_set >>= 1; + } + +#ifdef CONFIG_WL12XX_HT + /* MCS rates indication are on bits 16 - 23 */ + rate_set >>= HW_HT_RATES_OFFSET - band->n_bitrates; + + for (bit = 0; bit < 8; bit++) { + if (rate_set & 0x1) + enabled_rates |= (CONF_HW_BIT_RATE_MCS_0 << bit); + rate_set >>= 1; + } +#endif + + return enabled_rates; +} + +static void handle_tx_low_watermark(struct wl1271 *wl) +{ + unsigned long flags; + + if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) && + skb_queue_len(&wl->tx_queue) <= WL1271_TX_QUEUE_LOW_WATERMARK) { + /* firmware buffer has space, restart queues */ + spin_lock_irqsave(&wl->wl_lock, flags); + ieee80211_wake_queues(wl->hw); + clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags); + spin_unlock_irqrestore(&wl->wl_lock, flags); + } +} + +void wl1271_tx_work_locked(struct wl1271 *wl) +{ + struct sk_buff *skb; + bool woken_up = false; + u32 sta_rates = 0; + u32 buf_offset = 0; + bool sent_packets = false; + int ret; + + /* check if the rates supported by the AP have changed */ + if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED, + &wl->flags))) { + unsigned long flags; + + spin_lock_irqsave(&wl->wl_lock, flags); + sta_rates = wl->sta_rate_set; + spin_unlock_irqrestore(&wl->wl_lock, flags); + } + + if (unlikely(wl->state == WL1271_STATE_OFF)) + goto out; + + /* if rates have changed, re-configure the rate policy */ + if (unlikely(sta_rates)) { + ret = wl1271_ps_elp_wakeup(wl, false); + if (ret < 0) + goto out; + woken_up = true; + + wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates); + wl1271_acx_rate_policies(wl); + } + + while ((skb = skb_dequeue(&wl->tx_queue))) { + if (!woken_up) { + ret = wl1271_ps_elp_wakeup(wl, false); + if (ret < 0) + goto out_ack; + woken_up = true; + } + + ret = wl1271_prepare_tx_frame(wl, skb, buf_offset); + if (ret == -EAGAIN) { + /* + * Aggregation buffer is full. + * Flush buffer and try again. + */ + skb_queue_head(&wl->tx_queue, skb); + wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf, + buf_offset, true); + sent_packets = true; + buf_offset = 0; + continue; + } else if (ret == -EBUSY) { + /* + * Firmware buffer is full. + * Queue back last skb, and stop aggregating. + */ + skb_queue_head(&wl->tx_queue, skb); + /* No work left, avoid scheduling redundant tx work */ + set_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags); + goto out_ack; + } else if (ret < 0) { + dev_kfree_skb(skb); + goto out_ack; + } + buf_offset += ret; + wl->tx_packets_count++; + } + +out_ack: + if (buf_offset) { + wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf, + buf_offset, true); + sent_packets = true; + } + if (sent_packets) { + /* interrupt the firmware with the new packets */ + wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count); + handle_tx_low_watermark(wl); + } + +out: + if (woken_up) + wl1271_ps_elp_sleep(wl); +} + +void wl1271_tx_work(struct work_struct *work) +{ + struct wl1271 *wl = container_of(work, struct wl1271, tx_work); + + mutex_lock(&wl->mutex); + wl1271_tx_work_locked(wl); + mutex_unlock(&wl->mutex); +} + +static void wl1271_tx_complete_packet(struct wl1271 *wl, + struct wl1271_tx_hw_res_descr *result) +{ + struct ieee80211_tx_info *info; + struct sk_buff *skb; + int id = result->id; + int rate = -1; + u8 retries = 0; + + /* check for id legality */ + if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) { + wl1271_warning("TX result illegal id: %d", id); + return; + } + + skb = wl->tx_frames[id]; + info = IEEE80211_SKB_CB(skb); + + /* update the TX status info */ + if (result->status == TX_SUCCESS) { + if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) + info->flags |= IEEE80211_TX_STAT_ACK; + rate = wl1271_rate_to_idx(result->rate_class_index, wl->band); + retries = result->ack_failures; + } else if (result->status == TX_RETRY_EXCEEDED) { + wl->stats.excessive_retries++; + retries = result->ack_failures; + } + + info->status.rates[0].idx = rate; + info->status.rates[0].count = retries; + info->status.rates[0].flags = 0; + info->status.ack_signal = -1; + + wl->stats.retry_count += result->ack_failures; + + /* update security sequence number */ + wl->tx_security_seq += (result->lsb_security_sequence_number - + wl->tx_security_last_seq); + wl->tx_security_last_seq = result->lsb_security_sequence_number; + + /* remove private header from packet */ + skb_pull(skb, sizeof(struct wl1271_tx_hw_descr)); + + /* remove TKIP header space if present */ + if (info->control.hw_key && + info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) { + int hdrlen = ieee80211_get_hdrlen_from_skb(skb); + memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen); + skb_pull(skb, WL1271_TKIP_IV_SPACE); + } + + wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x" + " status 0x%x", + result->id, skb, result->ack_failures, + result->rate_class_index, result->status); + + /* return the packet to the stack */ + ieee80211_tx_status(wl->hw, skb); + wl1271_free_tx_id(wl, result->id); +} + +/* Called upon reception of a TX complete interrupt */ +void wl1271_tx_complete(struct wl1271 *wl) +{ + struct wl1271_acx_mem_map *memmap = + (struct wl1271_acx_mem_map *)wl->target_mem_map; + u32 count, fw_counter; + u32 i; + + /* read the tx results from the chipset */ + wl1271_read(wl, le32_to_cpu(memmap->tx_result), + wl->tx_res_if, sizeof(*wl->tx_res_if), false); + fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter); + + /* write host counter to chipset (to ack) */ + wl1271_write32(wl, le32_to_cpu(memmap->tx_result) + + offsetof(struct wl1271_tx_hw_res_if, + tx_result_host_counter), fw_counter); + + count = fw_counter - wl->tx_results_count; + wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count); + + /* verify that the result buffer is not getting overrun */ + if (unlikely(count > TX_HW_RESULT_QUEUE_LEN)) + wl1271_warning("TX result overflow from chipset: %d", count); + + /* process the results */ + for (i = 0; i < count; i++) { + struct wl1271_tx_hw_res_descr *result; + u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK; + + /* process the packet */ + result = &(wl->tx_res_if->tx_results_queue[offset]); + wl1271_tx_complete_packet(wl, result); + + wl->tx_results_count++; + } +} + +/* caller must hold wl->mutex */ +void wl1271_tx_reset(struct wl1271 *wl) +{ + int i; + struct sk_buff *skb; + + /* TX failure */ + while ((skb = skb_dequeue(&wl->tx_queue))) { + wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb); + ieee80211_tx_status(wl->hw, skb); + } + + /* + * Make sure the driver is at a consistent state, in case this + * function is called from a context other than interface removal. + */ + handle_tx_low_watermark(wl); + + for (i = 0; i < ACX_TX_DESCRIPTORS; i++) + if (wl->tx_frames[i] != NULL) { + skb = wl->tx_frames[i]; + wl1271_free_tx_id(wl, i); + wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb); + ieee80211_tx_status(wl->hw, skb); + } +} + +#define WL1271_TX_FLUSH_TIMEOUT 500000 + +/* caller must *NOT* hold wl->mutex */ +void wl1271_tx_flush(struct wl1271 *wl) +{ + unsigned long timeout; + timeout = jiffies + usecs_to_jiffies(WL1271_TX_FLUSH_TIMEOUT); + + while (!time_after(jiffies, timeout)) { + mutex_lock(&wl->mutex); + wl1271_debug(DEBUG_TX, "flushing tx buffer: %d", + wl->tx_frames_cnt); + if ((wl->tx_frames_cnt == 0) && + skb_queue_empty(&wl->tx_queue)) { + mutex_unlock(&wl->mutex); + return; + } + mutex_unlock(&wl->mutex); + msleep(1); + } + + wl1271_warning("Unable to flush all TX buffers, timed out."); +} |