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: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 7f669a2..38cc40c 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -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);

diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 2d44fe5..9dbb7dd 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -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;