1 files changed, 522 insertions, 0 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/dma.c b/drivers/net/wireless/mediatek/mt76/mt76x0/dma.c
new file mode 100644
index 000000000000..e2efb430419b
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/dma.c
@@ -0,0 +1,522 @@
+/*
+ * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
+ * Copyright (C) 2018 Stanislaw Gruszka <stf_xl@wp.pl>
+ *
+ * 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.
+ */
+
+#include "mt76x0.h"
+#include "dma.h"
+#include "usb.h"
+#include "trace.h"
+
+static int mt76x0_submit_rx_buf(struct mt76x0_dev *dev,
+				 struct mt76x0_dma_buf_rx *e, gfp_t gfp);
+
+static unsigned int ieee80211_get_hdrlen_from_buf(const u8 *data, unsigned len)
+{
+	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)data;
+	unsigned int hdrlen;
+
+	if (unlikely(len < 10))
+		return 0;
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
+	if (unlikely(hdrlen > len))
+		return 0;
+	return hdrlen;
+}
+
+static struct sk_buff *
+mt76x0_rx_skb_from_seg(struct mt76x0_dev *dev, struct mt76x0_rxwi *rxwi,
+			void *data, u32 seg_len, u32 truesize, struct page *p)
+{
+	struct sk_buff *skb;
+	u32 true_len, hdr_len = 0, copy, frag;
+
+	skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+
+	true_len = mt76x0_mac_process_rx(dev, skb, data, rxwi);
+	if (!true_len || true_len > seg_len)
+		goto bad_frame;
+
+	hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len);
+	if (!hdr_len)
+		goto bad_frame;
+
+	if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) {
+		memcpy(skb_put(skb, hdr_len), data, hdr_len);
+
+		data += hdr_len + 2;
+		true_len -= hdr_len;
+		hdr_len = 0;
+	}
+
+	/* If not doing paged RX allocated skb will always have enough space */
+	copy = (true_len <= skb_tailroom(skb)) ? true_len : hdr_len + 8;
+	frag = true_len - copy;
+
+	memcpy(skb_put(skb, copy), data, copy);
+	data += copy;
+
+	if (frag) {
+		skb_add_rx_frag(skb, 0, p, data - page_address(p),
+				frag, truesize);
+		get_page(p);
+	}
+
+	return skb;
+
+bad_frame:
+	dev_err_ratelimited(dev->mt76.dev, "Error: incorrect frame len:%u hdr:%u\n",
+			    true_len, hdr_len);
+	dev_kfree_skb(skb);
+	return NULL;
+}
+
+static void mt76x0_rx_process_seg(struct mt76x0_dev *dev, u8 *data,
+				   u32 seg_len, struct page *p)
+{
+	struct sk_buff *skb;
+	struct mt76x0_rxwi *rxwi;
+	u32 fce_info, truesize = seg_len;
+
+	/* DMA_INFO field at the beginning of the segment contains only some of
+	 * the information, we need to read the FCE descriptor from the end.
+	 */
+	fce_info = get_unaligned_le32(data + seg_len - MT_FCE_INFO_LEN);
+	seg_len -= MT_FCE_INFO_LEN;
+
+	data += MT_DMA_HDR_LEN;
+	seg_len -= MT_DMA_HDR_LEN;
+
+	rxwi = (struct mt76x0_rxwi *) data;
+	data += sizeof(struct mt76x0_rxwi);
+	seg_len -= sizeof(struct mt76x0_rxwi);
+
+	if (unlikely(FIELD_GET(MT_RXD_INFO_TYPE, fce_info)))
+		dev_err_once(dev->mt76.dev, "Error: RX path seen a non-pkt urb\n");
+
+	trace_mt76x0_rx(&dev->mt76, rxwi, fce_info);
+
+	skb = mt76x0_rx_skb_from_seg(dev, rxwi, data, seg_len, truesize, p);
+	if (!skb)
+		return;
+
+	spin_lock(&dev->mac_lock);
+	ieee80211_rx(dev->mt76.hw, skb);
+	spin_unlock(&dev->mac_lock);
+}
+
+static u16 mt76x0_rx_next_seg_len(u8 *data, u32 data_len)
+{
+	u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
+		sizeof(struct mt76x0_rxwi) + MT_FCE_INFO_LEN;
+	u16 dma_len = get_unaligned_le16(data);
+
+	if (data_len < min_seg_len ||
+	    WARN_ON(!dma_len) ||
+	    WARN_ON(dma_len + MT_DMA_HDRS > data_len) ||
+	    WARN_ON(dma_len & 0x3))
+		return 0;
+
+	return MT_DMA_HDRS + dma_len;
+}
+
+static void
+mt76x0_rx_process_entry(struct mt76x0_dev *dev, struct mt76x0_dma_buf_rx *e)
+{
+	u32 seg_len, data_len = e->urb->actual_length;
+	u8 *data = page_address(e->p);
+	struct page *new_p = NULL;
+	int cnt = 0;
+
+	if (!test_bit(MT76_STATE_INITIALIZED, &dev->mt76.state))
+		return;
+
+	/* Copy if there is very little data in the buffer. */
+	if (data_len > 512)
+		new_p = dev_alloc_pages(MT_RX_ORDER);
+
+	while ((seg_len = mt76x0_rx_next_seg_len(data, data_len))) {
+		mt76x0_rx_process_seg(dev, data, seg_len, new_p ? e->p : NULL);
+
+		data_len -= seg_len;
+		data += seg_len;
+		cnt++;
+	}
+
+	if (cnt > 1)
+		trace_mt76x0_rx_dma_aggr(&dev->mt76, cnt, !!new_p);
+
+	if (new_p) {
+		/* we have one extra ref from the allocator */
+		__free_pages(e->p, MT_RX_ORDER);
+
+		e->p = new_p;
+	}
+}
+
+static struct mt76x0_dma_buf_rx *
+mt76x0_rx_get_pending_entry(struct mt76x0_dev *dev)
+{
+	struct mt76x0_rx_queue *q = &dev->rx_q;
+	struct mt76x0_dma_buf_rx *buf = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->rx_lock, flags);
+
+	if (!q->pending)
+		goto out;
+
+	buf = &q->e[q->start];
+	q->pending--;
+	q->start = (q->start + 1) % q->entries;
+out:
+	spin_unlock_irqrestore(&dev->rx_lock, flags);
+
+	return buf;
+}
+
+static void mt76x0_complete_rx(struct urb *urb)
+{
+	struct mt76x0_dev *dev = urb->context;
+	struct mt76x0_rx_queue *q = &dev->rx_q;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->rx_lock, flags);
+
+	if (mt76x0_urb_has_error(urb))
+		dev_err(dev->mt76.dev, "Error: RX urb failed:%d\n", urb->status);
+	if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
+		goto out;
+
+	q->end = (q->end + 1) % q->entries;
+	q->pending++;
+	tasklet_schedule(&dev->rx_tasklet);
+out:
+	spin_unlock_irqrestore(&dev->rx_lock, flags);
+}
+
+static void mt76x0_rx_tasklet(unsigned long data)
+{
+	struct mt76x0_dev *dev = (struct mt76x0_dev *) data;
+	struct mt76x0_dma_buf_rx *e;
+
+	while ((e = mt76x0_rx_get_pending_entry(dev))) {
+		if (e->urb->status)
+			continue;
+
+		mt76x0_rx_process_entry(dev, e);
+		mt76x0_submit_rx_buf(dev, e, GFP_ATOMIC);
+	}
+}
+
+static void mt76x0_complete_tx(struct urb *urb)
+{
+	struct mt76x0_tx_queue *q = urb->context;
+	struct mt76x0_dev *dev = q->dev;
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->tx_lock, flags);
+
+	if (mt76x0_urb_has_error(urb))
+		dev_err(dev->mt76.dev, "Error: TX urb failed:%d\n", urb->status);
+	if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
+		goto out;
+
+	skb = q->e[q->start].skb;
+	trace_mt76x0_tx_dma_done(&dev->mt76, skb);
+
+	__skb_queue_tail(&dev->tx_skb_done, skb);
+	tasklet_schedule(&dev->tx_tasklet);
+
+	if (q->used == q->entries - q->entries / 8)
+		ieee80211_wake_queue(dev->mt76.hw, skb_get_queue_mapping(skb));
+
+	q->start = (q->start + 1) % q->entries;
+	q->used--;
+out:
+	spin_unlock_irqrestore(&dev->tx_lock, flags);
+}
+
+static void mt76x0_tx_tasklet(unsigned long data)
+{
+	struct mt76x0_dev *dev = (struct mt76x0_dev *) data;
+	struct sk_buff_head skbs;
+	unsigned long flags;
+
+	__skb_queue_head_init(&skbs);
+
+	spin_lock_irqsave(&dev->tx_lock, flags);
+
+	set_bit(MT76_MORE_STATS, &dev->mt76.state);
+	if (!test_and_set_bit(MT76_READING_STATS, &dev->mt76.state))
+		queue_delayed_work(dev->stat_wq, &dev->stat_work,
+				   msecs_to_jiffies(10));
+
+	skb_queue_splice_init(&dev->tx_skb_done, &skbs);
+
+	spin_unlock_irqrestore(&dev->tx_lock, flags);
+
+	while (!skb_queue_empty(&skbs)) {
+		struct sk_buff *skb = __skb_dequeue(&skbs);
+
+		mt76x0_tx_status(dev, skb);
+	}
+}
+
+static int mt76x0_dma_submit_tx(struct mt76x0_dev *dev,
+				 struct sk_buff *skb, u8 ep)
+{
+	struct usb_device *usb_dev = mt76x0_to_usb_dev(dev);
+	unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_ep[ep]);
+	struct mt76x0_dma_buf_tx *e;
+	struct mt76x0_tx_queue *q = &dev->tx_q[ep];
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&dev->tx_lock, flags);
+
+	if (WARN_ON_ONCE(q->entries <= q->used)) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	e = &q->e[q->end];
+	e->skb = skb;
+	usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
+			  mt76x0_complete_tx, q);
+	ret = usb_submit_urb(e->urb, GFP_ATOMIC);
+	if (ret) {
+		/* Special-handle ENODEV from TX urb submission because it will
+		 * often be the first ENODEV we see after device is removed.
+		 */
+		if (ret == -ENODEV)
+			set_bit(MT76_REMOVED, &dev->mt76.state);
+		else
+			dev_err(dev->mt76.dev, "Error: TX urb submit failed:%d\n",
+				ret);
+		goto out;
+	}
+
+	q->end = (q->end + 1) % q->entries;
+	q->used++;
+
+	if (q->used >= q->entries)
+		ieee80211_stop_queue(dev->mt76.hw, skb_get_queue_mapping(skb));
+out:
+	spin_unlock_irqrestore(&dev->tx_lock, flags);
+
+	return ret;
+}
+
+/* Map USB endpoint number to Q id in the DMA engine */
+static enum mt76_qsel ep2dmaq(u8 ep)
+{
+	if (ep == 5)
+		return MT_QSEL_MGMT;
+	return MT_QSEL_EDCA;
+}
+
+int mt76x0_dma_enqueue_tx(struct mt76x0_dev *dev, struct sk_buff *skb,
+			   struct mt76_wcid *wcid, int hw_q)
+{
+	u8 ep = q2ep(hw_q);
+	u32 dma_flags;
+	int ret;
+
+	dma_flags = MT_TXD_PKT_INFO_80211;
+	if (wcid->hw_key_idx == 0xff)
+		dma_flags |= MT_TXD_PKT_INFO_WIV;
+
+	ret = mt76x0_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
+	if (ret)
+		return ret;
+
+	ret = mt76x0_dma_submit_tx(dev, skb, ep);
+
+	if (ret) {
+		ieee80211_free_txskb(dev->mt76.hw, skb);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mt76x0_kill_rx(struct mt76x0_dev *dev)
+{
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->rx_lock, flags);
+
+	for (i = 0; i < dev->rx_q.entries; i++) {
+		int next = dev->rx_q.end;
+
+		spin_unlock_irqrestore(&dev->rx_lock, flags);
+		usb_poison_urb(dev->rx_q.e[next].urb);
+		spin_lock_irqsave(&dev->rx_lock, flags);
+	}
+
+	spin_unlock_irqrestore(&dev->rx_lock, flags);
+}
+
+static int mt76x0_submit_rx_buf(struct mt76x0_dev *dev,
+				 struct mt76x0_dma_buf_rx *e, gfp_t gfp)
+{
+	struct usb_device *usb_dev = mt76x0_to_usb_dev(dev);
+	u8 *buf = page_address(e->p);
+	unsigned pipe;
+	int ret;
+
+	pipe = usb_rcvbulkpipe(usb_dev, dev->in_ep[MT_EP_IN_PKT_RX]);
+
+	usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
+			  mt76x0_complete_rx, dev);
+
+	trace_mt76x0_submit_urb(&dev->mt76, e->urb);
+	ret = usb_submit_urb(e->urb, gfp);
+	if (ret)
+		dev_err(dev->mt76.dev, "Error: submit RX URB failed:%d\n", ret);
+
+	return ret;
+}
+
+static int mt76x0_submit_rx(struct mt76x0_dev *dev)
+{
+	int i, ret;
+
+	for (i = 0; i < dev->rx_q.entries; i++) {
+		ret = mt76x0_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void mt76x0_free_rx(struct mt76x0_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < dev->rx_q.entries; i++) {
+		__free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
+		usb_free_urb(dev->rx_q.e[i].urb);
+	}
+}
+
+static int mt76x0_alloc_rx(struct mt76x0_dev *dev)
+{
+	int i;
+
+	memset(&dev->rx_q, 0, sizeof(dev->rx_q));
+	dev->rx_q.dev = dev;
+	dev->rx_q.entries = N_RX_ENTRIES;
+
+	for (i = 0; i < N_RX_ENTRIES; i++) {
+		dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
+		dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
+
+		if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void mt76x0_free_tx_queue(struct mt76x0_tx_queue *q)
+{
+	int i;
+
+	WARN_ON(q->used);
+
+	for (i = 0; i < q->entries; i++)  {
+		usb_poison_urb(q->e[i].urb);
+		usb_free_urb(q->e[i].urb);
+	}
+}
+
+static void mt76x0_free_tx(struct mt76x0_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < __MT_EP_OUT_MAX; i++)
+		mt76x0_free_tx_queue(&dev->tx_q[i]);
+}
+
+static int mt76x0_alloc_tx_queue(struct mt76x0_dev *dev,
+				  struct mt76x0_tx_queue *q)
+{
+	int i;
+
+	q->dev = dev;
+	q->entries = N_TX_ENTRIES;
+
+	for (i = 0; i < N_TX_ENTRIES; i++) {
+		q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!q->e[i].urb)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int mt76x0_alloc_tx(struct mt76x0_dev *dev)
+{
+	int i;
+
+	dev->tx_q = devm_kcalloc(dev->mt76.dev, __MT_EP_OUT_MAX,
+				 sizeof(*dev->tx_q), GFP_KERNEL);
+
+	for (i = 0; i < __MT_EP_OUT_MAX; i++)
+		if (mt76x0_alloc_tx_queue(dev, &dev->tx_q[i]))
+			return -ENOMEM;
+
+	return 0;
+}
+
+int mt76x0_dma_init(struct mt76x0_dev *dev)
+{
+	int ret = -ENOMEM;
+
+	tasklet_init(&dev->tx_tasklet, mt76x0_tx_tasklet, (unsigned long) dev);
+	tasklet_init(&dev->rx_tasklet, mt76x0_rx_tasklet, (unsigned long) dev);
+
+	ret = mt76x0_alloc_tx(dev);
+	if (ret)
+		goto err;
+	ret = mt76x0_alloc_rx(dev);
+	if (ret)
+		goto err;
+
+	ret = mt76x0_submit_rx(dev);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	mt76x0_dma_cleanup(dev);
+	return ret;
+}
+
+void mt76x0_dma_cleanup(struct mt76x0_dev *dev)
+{
+	mt76x0_kill_rx(dev);
+
+	tasklet_kill(&dev->rx_tasklet);
+
+	mt76x0_free_rx(dev);
+	mt76x0_free_tx(dev);
+
+	tasklet_kill(&dev->tx_tasklet);
+}