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path: root/drivers/net/wireless/mediatek/mt76/dma.c
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Diffstat (limited to 'drivers/net/wireless/mediatek/mt76/dma.c')
-rw-r--r--drivers/net/wireless/mediatek/mt76/dma.c459
1 files changed, 459 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 0000000..3518703
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -0,0 +1,459 @@
+/*
+ * 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;
+ 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);
+}
+
+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 page *page = virt_to_head_page(data);
+ int offset = data - page_address(page);
+ struct sk_buff *skb = q->rx_head;
+
+ offset += q->buf_offset;
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, len,
+ q->buf_size);
+
+ if (more)
+ return;
+
+ q->rx_head = NULL;
+ dev->drv->rx_skb(dev, q - dev->q_rx, 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);
+ 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_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);
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