1 files changed, 546 insertions, 0 deletions
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
new file mode 100644
index 000000000..57866c1e9
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -0,0 +1,546 @@
+/*
+ * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/dma-mapping.h>
+#include "mt76.h"
+#include "dma.h"
+
+#define DMA_DUMMY_TXWI	((void *) ~0)
+
+static int
+mt76_dma_alloc_queue(struct mt76_dev *dev, struct mt76_queue *q)
+{
+	int size;
+	int i;
+
+	spin_lock_init(&q->lock);
+	INIT_LIST_HEAD(&q->swq);
+
+	size = q->ndesc * sizeof(struct mt76_desc);
+	q->desc = dmam_alloc_coherent(dev->dev, size, &q->desc_dma, GFP_KERNEL);
+	if (!q->desc)
+		return -ENOMEM;
+
+	size = q->ndesc * sizeof(*q->entry);
+	q->entry = devm_kzalloc(dev->dev, size, GFP_KERNEL);
+	if (!q->entry)
+		return -ENOMEM;
+
+	/* clear descriptors */
+	for (i = 0; i < q->ndesc; i++)
+		q->desc[i].ctrl = cpu_to_le32(MT_DMA_CTL_DMA_DONE);
+
+	iowrite32(q->desc_dma, &q->regs->desc_base);
+	iowrite32(0, &q->regs->cpu_idx);
+	iowrite32(0, &q->regs->dma_idx);
+	iowrite32(q->ndesc, &q->regs->ring_size);
+
+	return 0;
+}
+
+static int
+mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
+		 struct mt76_queue_buf *buf, int nbufs, u32 info,
+		 struct sk_buff *skb, void *txwi)
+{
+	struct mt76_desc *desc;
+	u32 ctrl;
+	int i, idx = -1;
+
+	if (txwi)
+		q->entry[q->head].txwi = DMA_DUMMY_TXWI;
+
+	for (i = 0; i < nbufs; i += 2, buf += 2) {
+		u32 buf0 = buf[0].addr, buf1 = 0;
+
+		ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len);
+		if (i < nbufs - 1) {
+			buf1 = buf[1].addr;
+			ctrl |= FIELD_PREP(MT_DMA_CTL_SD_LEN1, buf[1].len);
+		}
+
+		if (i == nbufs - 1)
+			ctrl |= MT_DMA_CTL_LAST_SEC0;
+		else if (i == nbufs - 2)
+			ctrl |= MT_DMA_CTL_LAST_SEC1;
+
+		idx = q->head;
+		q->head = (q->head + 1) % q->ndesc;
+
+		desc = &q->desc[idx];
+
+		WRITE_ONCE(desc->buf0, cpu_to_le32(buf0));
+		WRITE_ONCE(desc->buf1, cpu_to_le32(buf1));
+		WRITE_ONCE(desc->info, cpu_to_le32(info));
+		WRITE_ONCE(desc->ctrl, cpu_to_le32(ctrl));
+
+		q->queued++;
+	}
+
+	q->entry[idx].txwi = txwi;
+	q->entry[idx].skb = skb;
+
+	return idx;
+}
+
+static void
+mt76_dma_tx_cleanup_idx(struct mt76_dev *dev, struct mt76_queue *q, int idx,
+			struct mt76_queue_entry *prev_e)
+{
+	struct mt76_queue_entry *e = &q->entry[idx];
+	__le32 __ctrl = READ_ONCE(q->desc[idx].ctrl);
+	u32 ctrl = le32_to_cpu(__ctrl);
+
+	if (!e->txwi || !e->skb) {
+		__le32 addr = READ_ONCE(q->desc[idx].buf0);
+		u32 len = FIELD_GET(MT_DMA_CTL_SD_LEN0, ctrl);
+
+		dma_unmap_single(dev->dev, le32_to_cpu(addr), len,
+				 DMA_TO_DEVICE);
+	}
+
+	if (!(ctrl & MT_DMA_CTL_LAST_SEC0)) {
+		__le32 addr = READ_ONCE(q->desc[idx].buf1);
+		u32 len = FIELD_GET(MT_DMA_CTL_SD_LEN1, ctrl);
+
+		dma_unmap_single(dev->dev, le32_to_cpu(addr), len,
+				 DMA_TO_DEVICE);
+	}
+
+	if (e->txwi == DMA_DUMMY_TXWI)
+		e->txwi = NULL;
+
+	*prev_e = *e;
+	memset(e, 0, sizeof(*e));
+}
+
+static void
+mt76_dma_sync_idx(struct mt76_dev *dev, struct mt76_queue *q)
+{
+	q->head = ioread32(&q->regs->dma_idx);
+	q->tail = q->head;
+	iowrite32(q->head, &q->regs->cpu_idx);
+}
+
+static void
+mt76_dma_tx_cleanup(struct mt76_dev *dev, enum mt76_txq_id qid, bool flush)
+{
+	struct mt76_queue *q = &dev->q_tx[qid];
+	struct mt76_queue_entry entry;
+	bool wake = false;
+	int last;
+
+	if (!q->ndesc)
+		return;
+
+	spin_lock_bh(&q->lock);
+	if (flush)
+		last = -1;
+	else
+		last = ioread32(&q->regs->dma_idx);
+
+	while (q->queued && q->tail != last) {
+		mt76_dma_tx_cleanup_idx(dev, q, q->tail, &entry);
+		if (entry.schedule)
+			q->swq_queued--;
+
+		if (entry.skb)
+			dev->drv->tx_complete_skb(dev, q, &entry, flush);
+
+		if (entry.txwi) {
+			mt76_put_txwi(dev, entry.txwi);
+			wake = true;
+		}
+
+		q->tail = (q->tail + 1) % q->ndesc;
+		q->queued--;
+
+		if (!flush && q->tail == last)
+			last = ioread32(&q->regs->dma_idx);
+	}
+
+	if (!flush)
+		mt76_txq_schedule(dev, q);
+	else
+		mt76_dma_sync_idx(dev, q);
+
+	wake = wake && qid < IEEE80211_NUM_ACS && q->queued < q->ndesc - 8;
+
+	if (!q->queued)
+		wake_up(&dev->tx_wait);
+
+	spin_unlock_bh(&q->lock);
+
+	if (wake)
+		ieee80211_wake_queue(dev->hw, qid);
+}
+
+static void *
+mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
+		 int *len, u32 *info, bool *more)
+{
+	struct mt76_queue_entry *e = &q->entry[idx];
+	struct mt76_desc *desc = &q->desc[idx];
+	dma_addr_t buf_addr;
+	void *buf = e->buf;
+	int buf_len = SKB_WITH_OVERHEAD(q->buf_size);
+
+	buf_addr = le32_to_cpu(READ_ONCE(desc->buf0));
+	if (len) {
+		u32 ctl = le32_to_cpu(READ_ONCE(desc->ctrl));
+		*len = FIELD_GET(MT_DMA_CTL_SD_LEN0, ctl);
+		*more = !(ctl & MT_DMA_CTL_LAST_SEC0);
+	}
+
+	if (info)
+		*info = le32_to_cpu(desc->info);
+
+	dma_unmap_single(dev->dev, buf_addr, buf_len, DMA_FROM_DEVICE);
+	e->buf = NULL;
+
+	return buf;
+}
+
+static void *
+mt76_dma_dequeue(struct mt76_dev *dev, struct mt76_queue *q, bool flush,
+		 int *len, u32 *info, bool *more)
+{
+	int idx = q->tail;
+
+	*more = false;
+	if (!q->queued)
+		return NULL;
+
+	if (!flush && !(q->desc[idx].ctrl & cpu_to_le32(MT_DMA_CTL_DMA_DONE)))
+		return NULL;
+
+	q->tail = (q->tail + 1) % q->ndesc;
+	q->queued--;
+
+	return mt76_dma_get_buf(dev, q, idx, len, info, more);
+}
+
+static void
+mt76_dma_kick_queue(struct mt76_dev *dev, struct mt76_queue *q)
+{
+	iowrite32(q->head, &q->regs->cpu_idx);
+}
+
+int mt76_dma_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q,
+			  struct sk_buff *skb, struct mt76_wcid *wcid,
+			  struct ieee80211_sta *sta)
+{
+	struct mt76_queue_entry e;
+	struct mt76_txwi_cache *t;
+	struct mt76_queue_buf buf[32];
+	struct sk_buff *iter;
+	dma_addr_t addr;
+	int len;
+	u32 tx_info = 0;
+	int n, ret;
+
+	t = mt76_get_txwi(dev);
+	if (!t) {
+		ieee80211_free_txskb(dev->hw, skb);
+		return -ENOMEM;
+	}
+
+	dma_sync_single_for_cpu(dev->dev, t->dma_addr, sizeof(t->txwi),
+				DMA_TO_DEVICE);
+	ret = dev->drv->tx_prepare_skb(dev, &t->txwi, skb, q, wcid, sta,
+				       &tx_info);
+	dma_sync_single_for_device(dev->dev, t->dma_addr, sizeof(t->txwi),
+				   DMA_TO_DEVICE);
+	if (ret < 0)
+		goto free;
+
+	len = skb->len - skb->data_len;
+	addr = dma_map_single(dev->dev, skb->data, len, DMA_TO_DEVICE);
+	if (dma_mapping_error(dev->dev, addr)) {
+		ret = -ENOMEM;
+		goto free;
+	}
+
+	n = 0;
+	buf[n].addr = t->dma_addr;
+	buf[n++].len = dev->drv->txwi_size;
+	buf[n].addr = addr;
+	buf[n++].len = len;
+
+	skb_walk_frags(skb, iter) {
+		if (n == ARRAY_SIZE(buf))
+			goto unmap;
+
+		addr = dma_map_single(dev->dev, iter->data, iter->len,
+				      DMA_TO_DEVICE);
+		if (dma_mapping_error(dev->dev, addr))
+			goto unmap;
+
+		buf[n].addr = addr;
+		buf[n++].len = iter->len;
+	}
+
+	if (q->queued + (n + 1) / 2 >= q->ndesc - 1)
+		goto unmap;
+
+	return dev->queue_ops->add_buf(dev, q, buf, n, tx_info, skb, t);
+
+unmap:
+	ret = -ENOMEM;
+	for (n--; n > 0; n--)
+		dma_unmap_single(dev->dev, buf[n].addr, buf[n].len,
+				 DMA_TO_DEVICE);
+
+free:
+	e.skb = skb;
+	e.txwi = t;
+	dev->drv->tx_complete_skb(dev, q, &e, true);
+	mt76_put_txwi(dev, t);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mt76_dma_tx_queue_skb);
+
+static int
+mt76_dma_rx_fill(struct mt76_dev *dev, struct mt76_queue *q, bool napi)
+{
+	dma_addr_t addr;
+	void *buf;
+	int frames = 0;
+	int len = SKB_WITH_OVERHEAD(q->buf_size);
+	int offset = q->buf_offset;
+	int idx;
+	void *(*alloc)(unsigned int fragsz);
+
+	if (napi)
+		alloc = napi_alloc_frag;
+	else
+		alloc = netdev_alloc_frag;
+
+	spin_lock_bh(&q->lock);
+
+	while (q->queued < q->ndesc - 1) {
+		struct mt76_queue_buf qbuf;
+
+		buf = alloc(q->buf_size);
+		if (!buf)
+			break;
+
+		addr = dma_map_single(dev->dev, buf, len, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev->dev, addr)) {
+			skb_free_frag(buf);
+			break;
+		}
+
+		qbuf.addr = addr + offset;
+		qbuf.len = len - offset;
+		idx = mt76_dma_add_buf(dev, q, &qbuf, 1, 0, buf, NULL);
+		frames++;
+	}
+
+	if (frames)
+		mt76_dma_kick_queue(dev, q);
+
+	spin_unlock_bh(&q->lock);
+
+	return frames;
+}
+
+static void
+mt76_dma_rx_cleanup(struct mt76_dev *dev, struct mt76_queue *q)
+{
+	void *buf;
+	bool more;
+
+	spin_lock_bh(&q->lock);
+	do {
+		buf = mt76_dma_dequeue(dev, q, true, NULL, NULL, &more);
+		if (!buf)
+			break;
+
+		skb_free_frag(buf);
+	} while (1);
+	spin_unlock_bh(&q->lock);
+}
+
+static void
+mt76_dma_rx_reset(struct mt76_dev *dev, enum mt76_rxq_id qid)
+{
+	struct mt76_queue *q = &dev->q_rx[qid];
+	int i;
+
+	for (i = 0; i < q->ndesc; i++)
+		q->desc[i].ctrl &= ~cpu_to_le32(MT_DMA_CTL_DMA_DONE);
+
+	mt76_dma_rx_cleanup(dev, q);
+	mt76_dma_sync_idx(dev, q);
+	mt76_dma_rx_fill(dev, q, false);
+}
+
+static void
+mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data,
+		  int len, bool more)
+{
+	struct sk_buff *skb = q->rx_head;
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	int nr_frags = shinfo->nr_frags;
+
+	if (nr_frags < ARRAY_SIZE(shinfo->frags)) {
+		struct page *page = virt_to_head_page(data);
+		int offset = data - page_address(page) + q->buf_offset;
+
+		skb_add_rx_frag(skb, nr_frags, page, offset, len, q->buf_size);
+	} else {
+		skb_free_frag(data);
+	}
+
+	if (more)
+		return;
+
+	q->rx_head = NULL;
+	if (nr_frags < ARRAY_SIZE(shinfo->frags))
+		dev->drv->rx_skb(dev, q - dev->q_rx, skb);
+	else
+		dev_kfree_skb(skb);
+}
+
+static int
+mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
+{
+	struct sk_buff *skb;
+	unsigned char *data;
+	int len;
+	int done = 0;
+	bool more;
+
+	while (done < budget) {
+		u32 info;
+
+		data = mt76_dma_dequeue(dev, q, false, &len, &info, &more);
+		if (!data)
+			break;
+
+		if (q->rx_head) {
+			mt76_add_fragment(dev, q, data, len, more);
+			continue;
+		}
+
+		skb = build_skb(data, q->buf_size);
+		if (!skb) {
+			skb_free_frag(data);
+			continue;
+		}
+
+		skb_reserve(skb, q->buf_offset);
+		if (skb->tail + len > skb->end) {
+			dev_kfree_skb(skb);
+			continue;
+		}
+
+		if (q == &dev->q_rx[MT_RXQ_MCU]) {
+			u32 *rxfce = (u32 *) skb->cb;
+			*rxfce = info;
+		}
+
+		__skb_put(skb, len);
+		done++;
+
+		if (more) {
+			q->rx_head = skb;
+			continue;
+		}
+
+		dev->drv->rx_skb(dev, q - dev->q_rx, skb);
+	}
+
+	mt76_dma_rx_fill(dev, q, true);
+	return done;
+}
+
+static int
+mt76_dma_rx_poll(struct napi_struct *napi, int budget)
+{
+	struct mt76_dev *dev;
+	int qid, done = 0, cur;
+
+	dev = container_of(napi->dev, struct mt76_dev, napi_dev);
+	qid = napi - dev->napi;
+
+	rcu_read_lock();
+
+	do {
+		cur = mt76_dma_rx_process(dev, &dev->q_rx[qid], budget - done);
+		mt76_rx_poll_complete(dev, qid, napi);
+		done += cur;
+	} while (cur && done < budget);
+
+	rcu_read_unlock();
+
+	if (done < budget) {
+		napi_complete(napi);
+		dev->drv->rx_poll_complete(dev, qid);
+	}
+
+	return done;
+}
+
+static int
+mt76_dma_init(struct mt76_dev *dev)
+{
+	int i;
+
+	init_dummy_netdev(&dev->napi_dev);
+
+	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++) {
+		netif_napi_add(&dev->napi_dev, &dev->napi[i], mt76_dma_rx_poll,
+			       64);
+		mt76_dma_rx_fill(dev, &dev->q_rx[i], false);
+		skb_queue_head_init(&dev->rx_skb[i]);
+		napi_enable(&dev->napi[i]);
+	}
+
+	return 0;
+}
+
+static const struct mt76_queue_ops mt76_dma_ops = {
+	.init = mt76_dma_init,
+	.alloc = mt76_dma_alloc_queue,
+	.add_buf = mt76_dma_add_buf,
+	.tx_queue_skb = mt76_dma_tx_queue_skb,
+	.tx_cleanup = mt76_dma_tx_cleanup,
+	.rx_reset = mt76_dma_rx_reset,
+	.kick = mt76_dma_kick_queue,
+};
+
+int mt76_dma_attach(struct mt76_dev *dev)
+{
+	dev->queue_ops = &mt76_dma_ops;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mt76_dma_attach);
+
+void mt76_dma_cleanup(struct mt76_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(dev->q_tx); i++)
+		mt76_dma_tx_cleanup(dev, i, true);
+
+	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++) {
+		netif_napi_del(&dev->napi[i]);
+		mt76_dma_rx_cleanup(dev, &dev->q_rx[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(mt76_dma_cleanup);