iwmc3200wifi: Add new Intel Wireless Multicomm 802.11 driver

This driver supports Intel's full MAC wireless multicomm 802.11 hardware.
Although the hardware is a 802.11agn device, we currently only support
802.11ag, in managed and ad-hoc mode (no AP mode for now).

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Samuel Ortiz <samuel.ortiz@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 492 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwmc3200wifi/tx.c b/drivers/net/wireless/iwmc3200wifi/tx.c
new file mode 100644
index 000000000000..e3b4f7902daf
--- /dev/null
+++ b/drivers/net/wireless/iwmc3200wifi/tx.c
@@ -0,0 +1,492 @@
+/*
+ * 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/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 avaliable 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 int 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 0;
+}
+
+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);
+
+	ret = iwm_bus_send_chunk(iwm, txq->concat_buf, txq->concat_count);
+
+	txq->concat_count = 0;
+	txq->concat_ptr = txq->concat_buf;
+
+	return ret;
+}
+
+#define CONFIG_IWM_TX_CONCATENATED 1
+
+void iwm_tx_worker(struct work_struct *work)
+{
+	struct iwm_priv *iwm;
+	struct iwm_tx_info *tx_info = NULL;
+	struct sk_buff *skb;
+	int cmdlen, ret;
+	struct iwm_tx_queue *txq;
+	int 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)) {
+
+		skb = skb_dequeue(&txq->queue);
+		tx_info = skb_to_tx_info(skb);
+		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 !CONFIG_IWM_TX_CONCATENATED
+		/* temporarily keep this to comparing the performance */
+		ret = iwm_send_packet(iwm, skb, pool_id);
+#else
+
+		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);
+			skb_queue_head(&txq->queue, skb);
+			break;
+		}
+
+		txq->concat_ptr = txq->concat_buf + txq->concat_count;
+		iwm_tx_build_packet(iwm, skb, pool_id, txq->concat_ptr);
+		txq->concat_count += ALIGN(cmdlen, 16);
+#endif
+		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 net_device *ndev = iwm_to_ndev(iwm);
+	struct wireless_dev *wdev = iwm_to_wdev(iwm);
+	u8 *dst_addr;
+	struct iwm_tx_info *tx_info;
+	struct iwm_tx_queue *txq;
+	struct iwm_sta_info *sta_info;
+	u8 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) {
+		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;
+
+	skb_queue_tail(&iwm->txq[queue].queue, skb);
+
+	queue_work(iwm->txq[queue].wq, &iwm->txq[queue].worker);
+
+	ndev->stats.tx_packets++;
+	ndev->stats.tx_bytes += skb->len;
+	return NETDEV_TX_OK;
+
+ drop:
+	ndev->stats.tx_dropped++;
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}