/*
* Intel Wireless Multicomm 3200 WiFi driver
*
* Copyright (C) 2009 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
* Intel Corporation <ilw@linux.intel.com>
* Samuel Ortiz <samuel.ortiz@intel.com>
* Zhu Yi <yi.zhu@intel.com>
*
*/
/*
* iwm Tx theory of operation:
*
* 1) We receive a 802.3 frame from the stack
* 2) We convert it to a 802.11 frame [iwm_xmit_frame]
* 3) We queue it to its corresponding tx queue [iwm_xmit_frame]
* 4) We schedule the tx worker. There is one worker per tx
* queue. [iwm_xmit_frame]
* 5) The tx worker is scheduled
* 6) We go through every queued skb on the tx queue, and for each
* and every one of them: [iwm_tx_worker]
* a) We check if we have enough Tx credits (see below for a Tx
* credits description) for the frame length. [iwm_tx_worker]
* b) If we do, we aggregate the Tx frame into a UDMA one, by
* concatenating one REPLY_TX command per Tx frame. [iwm_tx_worker]
* c) When we run out of credits, or when we reach the maximum
* concatenation size, we actually send the concatenated UDMA
* frame. [iwm_tx_worker]
*
* When we run out of Tx credits, the skbs are filling the tx queue,
* and eventually we will stop the netdev queue. [iwm_tx_worker]
* The tx queue is emptied as we're getting new tx credits, by
* scheduling the tx_worker. [iwm_tx_credit_inc]
* The netdev queue is started again when we have enough tx credits,
* and when our tx queue has some reasonable amout of space available
* (i.e. half of the max size). [iwm_tx_worker]
*/
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/ieee80211.h>
#include "iwm.h"
#include "debug.h"
#include "commands.h"
#include "hal.h"
#include "umac.h"
#include "bus.h"
#define IWM_UMAC_PAGE_ALLOC_WRAP 0xffff
#define BYTES_TO_PAGES(n) (1 + ((n) >> ilog2(IWM_UMAC_PAGE_SIZE)) - \
(((n) & (IWM_UMAC_PAGE_SIZE - 1)) == 0))
#define pool_id_to_queue(id) ((id < IWM_TX_CMD_QUEUE) ? id : id - 1)
#define queue_to_pool_id(q) ((q < IWM_TX_CMD_QUEUE) ? q : q + 1)
/* require to hold tx_credit lock */
static int iwm_tx_credit_get(struct iwm_tx_credit *tx_credit, int id)
{
struct pool_entry *pool = &tx_credit->pools[id];
struct spool_entry *spool = &tx_credit->spools[pool->sid];
int spool_pages;
/* number of pages can be taken from spool by this pool */
spool_pages = spool->max_pages - spool->alloc_pages +
max(pool->min_pages - pool->alloc_pages, 0);
return min(pool->max_pages - pool->alloc_pages, spool_pages);
}
static bool iwm_tx_credit_ok(struct iwm_priv *iwm, int id, int nb)
{
u32 npages = BYTES_TO_PAGES(nb);
if (npages <= iwm_tx_credit_get(&iwm->tx_credit, id))
return 1;
set_bit(id, &iwm->tx_credit.full_pools_map);
IWM_DBG_TX(iwm, DBG, "LINK: stop txq[%d], available credit: %d\n",
pool_id_to_queue(id),
iwm_tx_credit_get(&iwm->tx_credit, id));
return 0;
}
void iwm_tx_credit_inc(struct iwm_priv *iwm, int id, int total_freed_pages)
{
struct pool_entry *pool;
struct spool_entry *spool;
int freed_pages;
int queue;
BUG_ON(id >= IWM_MACS_OUT_GROUPS);
pool = &iwm->tx_credit.pools[id];
spool = &iwm->tx_credit.spools[pool->sid];
freed_pages = total_freed_pages - pool->total_freed_pages;
IWM_DBG_TX(iwm, DBG, "Free %d pages for pool[%d]\n", freed_pages, id);
if (!freed_pages) {
IWM_DBG_TX(iwm, DBG, "No pages are freed by UMAC\n");
return;
} else if (freed_pages < 0)
freed_pages += IWM_UMAC_PAGE_ALLOC_WRAP + 1;
if (pool->alloc_pages > pool->min_pages) {
int spool_pages = pool->alloc_pages - pool->min_pages;
spool_pages = min(spool_pages, freed_pages);
spool->alloc_pages -= spool_pages;
}
pool->alloc_pages -= freed_pages;
pool->total_freed_pages = total_freed_pages;
IWM_DBG_TX(iwm, DBG, "Pool[%d] pages alloc: %d, total_freed: %d, "
"Spool[%d] pages alloc: %d\n", id, pool->alloc_pages,
pool->total_freed_pages, pool->sid, spool->alloc_pages);
if (test_bit(id, &iwm->tx_credit.full_pools_map) &&
(pool->alloc_pages < pool->max_pages / 2)) {
clear_bit(id, &iwm->tx_credit.full_pools_map);
queue = pool_id_to_queue(id);
IWM_DBG_TX(iwm, DBG, "LINK: start txq[%d], available "
"credit: %d\n", queue,
iwm_tx_credit_get(&iwm->tx_credit, id));
queue_work(iwm->txq[queue].wq, &iwm->txq[queue].worker);
}
}
static void iwm_tx_credit_dec(struct iwm_priv *iwm, int id, int alloc_pages)
{
struct pool_entry *pool;
struct spool_entry *spool;
int spool_pages;
IWM_DBG_TX(iwm, DBG, "Allocate %d pages for pool[%d]\n",
alloc_pages, id);
BUG_ON(id >= IWM_MACS_OUT_GROUPS);
pool = &iwm->tx_credit.pools[id];
spool = &iwm->tx_credit.spools[pool->sid];
spool_pages = pool->alloc_pages + alloc_pages - pool->min_pages;
if (pool->alloc_pages >= pool->min_pages)
spool->alloc_pages += alloc_pages;
else if (spool_pages > 0)
spool->alloc_pages += spool_pages;
pool->alloc_pages += alloc_pages;
IWM_DBG_TX(iwm, DBG, "Pool[%d] pages alloc: %d, total_freed: %d, "
"Spool[%d] pages alloc: %d\n", id, pool->alloc_pages,
pool->total_freed_pages, pool->sid, spool->alloc_pages);
}
int iwm_tx_credit_alloc(struct iwm_priv *iwm, int id, int nb)
{
u32 npages = BYTES_TO_PAGES(nb);
int ret = 0;
spin_lock(&iwm->tx_credit.lock);
if (!iwm_tx_credit_ok(iwm, id, nb)) {
IWM_DBG_TX(iwm, DBG, "No credit available for pool[%d]\n", id);
ret = -ENOSPC;
goto out;
}
iwm_tx_credit_dec(iwm, id, npages);
out:
spin_unlock(&iwm->tx_credit.lock);
return ret;
}
/*
* Since we're on an SDIO or USB bus, we are not sharing memory
* for storing to be transmitted frames. The host needs to push
* them upstream. As a consequence there needs to be a way for
* the target to let us know if it can actually take more TX frames
* or not. This is what Tx credits are for.
*
* For each Tx HW queue, we have a Tx pool, and then we have one
* unique super pool (spool), which is actually a global pool of
* all the UMAC pages.
* For each Tx pool we have a min_pages, a max_pages fields, and a
* alloc_pages fields. The alloc_pages tracks the number of pages
* currently allocated from the tx pool.
* Here are the rules to check if given a tx frame we have enough
* tx credits for it:
* 1) We translate the frame length into a number of UMAC pages.
* Let's call them n_pages.
* 2) For the corresponding tx pool, we check if n_pages +
* pool->alloc_pages is higher than pool->min_pages. min_pages
* represent a set of pre-allocated pages on the tx pool. If
* that's the case, then we need to allocate those pages from
* the spool. We can do so until we reach spool->max_pages.
* 3) Each tx pool is not allowed to allocate more than pool->max_pages
* from the spool, so once we're over min_pages, we can allocate
* pages from the spool, but not more than max_pages.
*
* When the tx code path needs to send a tx frame, it checks first
* if it has enough tx credits, following those rules. [iwm_tx_credit_get]
* If it does, it then updates the pool and spool counters and
* then send the frame. [iwm_tx_credit_alloc and iwm_tx_credit_dec]
* On the other side, when the UMAC is done transmitting frames, it
* will send a credit update notification to the host. This is when
* the pool and spool counters gets to be decreased. [iwm_tx_credit_inc,
* called from rx.c:iwm_ntf_tx_credit_update]
*
*/
void iwm_tx_credit_init_pools(struct iwm_priv *iwm,
struct iwm_umac_notif_alive *alive)
{
int i, sid, pool_pages;
spin_lock(&iwm->tx_credit.lock);
iwm->tx_credit.pool_nr = le16_to_cpu(alive->page_grp_count);
iwm->tx_credit.full_pools_map = 0;
memset(&iwm->tx_credit.spools[0], 0, sizeof(struct spool_entry));
IWM_DBG_TX(iwm, DBG, "Pools number is %d\n", iwm->tx_credit.pool_nr);
for (i = 0; i < iwm->tx_credit.pool_nr; i++) {
__le32 page_grp_state = alive->page_grp_state[i];
iwm->tx_credit.pools[i].id = GET_VAL32(page_grp_state,
UMAC_ALIVE_PAGE_STS_GRP_NUM);
iwm->tx_credit.pools[i].sid = GET_VAL32(page_grp_state,
UMAC_ALIVE_PAGE_STS_SGRP_NUM);
iwm->tx_credit.pools[i].min_pages = GET_VAL32(page_grp_state,
UMAC_ALIVE_PAGE_STS_GRP_MIN_SIZE);
iwm->tx_credit.pools[i].max_pages = GET_VAL32(page_grp_state,
UMAC_ALIVE_PAGE_STS_GRP_MAX_SIZE);
iwm->tx_credit.pools[i].alloc_pages = 0;
iwm->tx_credit.pools[i].total_freed_pages = 0;
sid = iwm->tx_credit.pools[i].sid;
pool_pages = iwm->tx_credit.pools[i].min_pages;
if (iwm->tx_credit.spools[sid].max_pages == 0) {
iwm->tx_credit.spools[sid].id = sid;
iwm->tx_credit.spools[sid].max_pages =
GET_VAL32(page_grp_state,
UMAC_ALIVE_PAGE_STS_SGRP_MAX_SIZE);
iwm->tx_credit.spools[sid].alloc_pages = 0;
}
iwm->tx_credit.spools[sid].alloc_pages += pool_pages;
IWM_DBG_TX(iwm, DBG, "Pool idx: %d, id: %d, sid: %d, capacity "
"min: %d, max: %d, pool alloc: %d, total_free: %d, "
"super poll alloc: %d\n",
i, iwm->tx_credit.pools[i].id,
iwm->tx_credit.pools[i].sid,
iwm->tx_credit.pools[i].min_pages,
iwm->tx_credit.pools[i].max_pages,
iwm->tx_credit.pools[i].alloc_pages,
iwm->tx_credit.pools[i].total_freed_pages,
iwm->tx_credit.spools[sid].alloc_pages);
}
spin_unlock(&iwm->tx_credit.lock);
}
#define IWM_UDMA_HDR_LEN sizeof(struct iwm_umac_wifi_out_hdr)
static __le16 iwm_tx_build_packet(struct iwm_priv *iwm, struct sk_buff *skb,
int pool_id, u8 *buf)
{
struct iwm_umac_wifi_out_hdr *hdr = (struct iwm_umac_wifi_out_hdr *)buf;
struct iwm_udma_wifi_cmd udma_cmd;
struct iwm_umac_cmd umac_cmd;
struct iwm_tx_info *tx_info = skb_to_tx_info(skb);
udma_cmd.count = cpu_to_le16(skb->len +
sizeof(struct iwm_umac_fw_cmd_hdr));
/* set EOP to 0 here. iwm_udma_wifi_hdr_set_eop() will be
* called later to set EOP for the last packet. */
udma_cmd.eop = 0;
udma_cmd.credit_group = pool_id;
udma_cmd.ra_tid = tx_info->sta << 4 | tx_info->tid;
udma_cmd.lmac_offset = 0;
umac_cmd.id = REPLY_TX;
umac_cmd.count = cpu_to_le16(skb->len);
umac_cmd.color = tx_info->color;
umac_cmd.resp = 0;
umac_cmd.seq_num = cpu_to_le16(iwm_alloc_wifi_cmd_seq(iwm));
iwm_build_udma_wifi_hdr(iwm, &hdr->hw_hdr, &udma_cmd);
iwm_build_umac_hdr(iwm, &hdr->sw_hdr, &umac_cmd);
memcpy(buf + sizeof(*hdr), skb->data, skb->len);
return umac_cmd.seq_num;
}
static int iwm_tx_send_concat_packets(struct iwm_priv *iwm,
struct iwm_tx_queue *txq)
{
int ret;
if (!txq->concat_count)
return 0;
IWM_DBG_TX(iwm, DBG, "Send concatenated Tx: queue %d, %d bytes\n",
txq->id, txq->concat_count);
/* mark EOP for the last packet */
iwm_udma_wifi_hdr_set_eop(iwm, txq->concat_ptr, 1);
trace_iwm_tx_packets(iwm, txq->concat_buf, txq->concat_count);
ret = iwm_bus_send_chunk(iwm, txq->concat_buf, txq->concat_count);
txq->concat_count = 0;
txq->concat_ptr = txq->concat_buf;
return ret;
}
void iwm_tx_worker(struct work_struct *work)
{
struct iwm_priv *iwm;
struct iwm_tx_info *tx_info = NULL;
struct sk_buff *skb;
struct iwm_tx_queue *txq;
struct iwm_sta_info *sta_info;
struct iwm_tid_info *tid_info;
int cmdlen, ret, pool_id;
txq = container_of(work, struct iwm_tx_queue, worker);
iwm = container_of(txq, struct iwm_priv, txq[txq->id]);
pool_id = queue_to_pool_id(txq->id);
while (!test_bit(pool_id, &iwm->tx_credit.full_pools_map) &&
!skb_queue_empty(&txq->queue)) {
spin_lock_bh(&txq->lock);
skb = skb_dequeue(&txq->queue);
spin_unlock_bh(&txq->lock);
tx_info = skb_to_tx_info(skb);
sta_info = &iwm->sta_table[tx_info->sta];
if (!sta_info->valid) {
IWM_ERR(iwm, "Trying to send a frame to unknown STA\n");
kfree_skb(skb);
continue;
}
tid_info = &sta_info->tid_info[tx_info->tid];
mutex_lock(&tid_info->mutex);
/*
* If the RAxTID is stopped, we queue the skb to the stopped
* queue.
* Whenever we'll get a UMAC notification to resume the tx flow
* for this RAxTID, we'll merge back the stopped queue into the
* regular queue. See iwm_ntf_stop_resume_tx() from rx.c.
*/
if (tid_info->stopped) {
IWM_DBG_TX(iwm, DBG, "%dx%d stopped\n",
tx_info->sta, tx_info->tid);
spin_lock_bh(&txq->lock);
skb_queue_tail(&txq->stopped_queue, skb);
spin_unlock_bh(&txq->lock);
mutex_unlock(&tid_info->mutex);
continue;
}
cmdlen = IWM_UDMA_HDR_LEN + skb->len;
IWM_DBG_TX(iwm, DBG, "Tx frame on queue %d: skb: 0x%p, sta: "
"%d, color: %d\n", txq->id, skb, tx_info->sta,
tx_info->color);
if (txq->concat_count + cmdlen > IWM_HAL_CONCATENATE_BUF_SIZE)
iwm_tx_send_concat_packets(iwm, txq);
ret = iwm_tx_credit_alloc(iwm, pool_id, cmdlen);
if (ret) {
IWM_DBG_TX(iwm, DBG, "not enough tx_credit for queue "
"%d, Tx worker stopped\n", txq->id);
spin_lock_bh(&txq->lock);
skb_queue_head(&txq->queue, skb);
spin_unlock_bh(&txq->lock);
mutex_unlock(&tid_info->mutex);
break;
}
txq->concat_ptr = txq->concat_buf + txq->concat_count;
tid_info->last_seq_num =
iwm_tx_build_packet(iwm, skb, pool_id, txq->concat_ptr);
txq->concat_count += ALIGN(cmdlen, 16);
mutex_unlock(&tid_info->mutex);
kfree_skb(skb);
}
iwm_tx_send_concat_packets(iwm, txq);
if (__netif_subqueue_stopped(iwm_to_ndev(iwm), txq->id) &&
!test_bit(pool_id, &iwm->tx_credit.full_pools_map) &&
(skb_queue_len(&txq->queue) < IWM_TX_LIST_SIZE / 2)) {
IWM_DBG_TX(iwm, DBG, "LINK: start netif_subqueue[%d]", txq->id);
netif_wake_subqueue(iwm_to_ndev(iwm), txq->id);
}
}
int iwm_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
struct iwm_priv *iwm = ndev_to_iwm(netdev);
struct wireless_dev *wdev = iwm_to_wdev(iwm);
struct iwm_tx_info *tx_info;
struct iwm_tx_queue *txq;
struct iwm_sta_info *sta_info;
u8 *dst_addr, sta_id;
u16 queue;
int ret;
if (!test_bit(IWM_STATUS_ASSOCIATED, &iwm->status)) {
IWM_DBG_TX(iwm, DBG, "LINK: stop netif_all_queues: "
"not associated\n");
netif_tx_stop_all_queues(netdev);
goto drop;
}
queue = skb_get_queue_mapping(skb);
BUG_ON(queue >= IWM_TX_DATA_QUEUES); /* no iPAN yet */
txq = &iwm->txq[queue];
/* No free space for Tx, tx_worker is too slow */
if ((skb_queue_len(&txq->queue) > IWM_TX_LIST_SIZE) ||
(skb_queue_len(&txq->stopped_queue) > IWM_TX_LIST_SIZE)) {
IWM_DBG_TX(iwm, DBG, "LINK: stop netif_subqueue[%d]\n", queue);
netif_stop_subqueue(netdev, queue);
return NETDEV_TX_BUSY;
}
ret = ieee80211_data_from_8023(skb, netdev->dev_addr, wdev->iftype,
iwm->bssid, 0);
if (ret) {
IWM_ERR(iwm, "build wifi header failed\n");
goto drop;
}
dst_addr = ((struct ieee80211_hdr *)(skb->data))->addr1;
for (sta_id = 0; sta_id < IWM_STA_TABLE_NUM; sta_id++) {
sta_info = &iwm->sta_table[sta_id];
if (sta_info->valid &&
!memcmp(dst_addr, sta_info->addr, ETH_ALEN))
break;
}
if (sta_id == IWM_STA_TABLE_NUM) {
IWM_ERR(iwm, "STA %pM not found in sta_table, Tx ignored\n",
dst_addr);
goto drop;
}
tx_info = skb_to_tx_info(skb);
tx_info->sta = sta_id;
tx_info->color = sta_info->color;
/* UMAC uses TID 8 (vs. 0) for non QoS packets */
if (sta_info->qos)
tx_info->tid = skb->priority;
else
tx_info->tid = IWM_UMAC_MGMT_TID;
spin_lock_bh(&iwm->txq[queue].lock);
skb_queue_tail(&iwm->txq[queue].queue, skb);
spin_unlock_bh(&iwm->txq[queue].lock);
queue_work(iwm->txq[queue].wq, &iwm->txq[queue].worker);
netdev->stats.tx_packets++;
netdev->stats.tx_bytes += skb->len;
return NETDEV_TX_OK;
drop:
netdev->stats.tx_dropped++;
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
