Commit 75d4bf1f authored by Felix Fietkau's avatar Felix Fietkau
Browse files

mt76: dma: cache dma map address/len in struct mt76_queue_entry 



Accessing them from uncached memory can be expensive, so it's cheaper to
cache them

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent 2fe1a5d6

drivers/net/wireless/mediatek/mt76/dma.c

+20 −23
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 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_queue_entry *entry;

	struct mt76_desc *desc;

	u32 ctrl;

	int i, idx = -1;
@@ -61,16 +62,27 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q, 
	for (i = 0; i < nbufs; i += 2, buf += 2) {

		u32 buf0 = buf[0].addr, buf1 = 0;



		idx = q->head;

		q->head = (q->head + 1) % q->ndesc;



		desc = &q->desc[idx];

		entry = &q->entry[idx];



		if (buf[0].skip_unmap)

			q->entry[q->head].skip_buf0 = true;

		q->entry[q->head].skip_buf1 = i == nbufs - 1;

			entry->skip_buf0 = true;

		entry->skip_buf1 = i == nbufs - 1;



		entry->dma_addr[0] = buf[0].addr;

		entry->dma_len[0] = buf[0].len;



		ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len);

		if (i < nbufs - 1) {

			entry->dma_addr[1] = buf[1].addr;

			entry->dma_len[1] = buf[1].len;

			buf1 = buf[1].addr;

			ctrl |= FIELD_PREP(MT_DMA_CTL_SD_LEN1, buf[1].len);

			if (buf[1].skip_unmap)

				q->entry[q->head].skip_buf1 = true;

				entry->skip_buf1 = true;

		}



		if (i == nbufs - 1)
@@ -78,11 +90,6 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q, 
		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));
@@ -102,24 +109,14 @@ 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->skip_buf0) {

		__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,

	if (!e->skip_buf0)

		dma_unmap_single(dev->dev, e->dma_addr[0], e->dma_len[0],

				 DMA_TO_DEVICE);

	}



	if (!e->skip_buf1) {

		__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,

	if (!e->skip_buf1)

		dma_unmap_single(dev->dev, e->dma_addr[1], e->dma_len[1],

				 DMA_TO_DEVICE);

	}



	if (e->txwi == DMA_DUMMY_DATA)

		e->txwi = NULL;
@@ -207,7 +204,7 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx, 
	void *buf = e->buf;

	int buf_len = SKB_WITH_OVERHEAD(q->buf_size);



	buf_addr = le32_to_cpu(READ_ONCE(desc->buf0));

	buf_addr = e->dma_addr[0];

	if (len) {

		u32 ctl = le32_to_cpu(READ_ONCE(desc->ctrl));

		*len = FIELD_GET(MT_DMA_CTL_SD_LEN0, ctl);

drivers/net/wireless/mediatek/mt76/mt76.h

+2 −0
Original line number Diff line number Diff line
@@ -102,6 +102,8 @@ struct mt76_queue_entry { 
		struct urb *urb;

		int buf_sz;

	};

	u32 dma_addr[2];

	u16 dma_len[2];

	u16 wcid;

	bool skip_buf0:1;

	bool skip_buf1:1;