[PATCH 1/3] wifi: mt76: Separate skb and page_pool_buf pointers in mt76_txwi_cache

[Eason Lai <eason.lai@mediatek.com>]

From: Eason Lai <Eason.Lai@mediatek.com>

Refactor mt76_txwi_cache structure to use separate skb and page_pool_buf
fields instead of a union with ptr. This improves type safety and makes
the code more explicit about which pointer type is being used in
different contexts.

Also add skip_unmap flag to tx_info.buf to handle cases where DMA
unmapping should be skipped.

Signed-off-by: Eason Lai <Eason.Lai@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/dma.c      | 29 ++++++++++++-------
 drivers/net/wireless/mediatek/mt76/mt76.h     |  4 +--
 .../net/wireless/mediatek/mt76/mt7996/mac.c   | 10 +++----
 drivers/net/wireless/mediatek/mt76/tx.c       |  2 +-
 drivers/net/wireless/mediatek/mt76/wed.c      |  6 ++--
 5 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index f8c2fe5f2f58..2716278788bd 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -43,7 +43,8 @@ mt76_alloc_rxwi(struct mt76_dev *dev)
 	if (!t)
 		return NULL;
 
-	t->ptr = NULL;
+	t->skb = NULL;
+	t->page_pool_buf = NULL;
 	return t;
 }
 
@@ -84,8 +85,11 @@ mt76_get_txwi(struct mt76_dev *dev)
 {
 	struct mt76_txwi_cache *t = __mt76_get_txwi(dev);
 
-	if (t)
+	if (t) {
+		t->skb = NULL;
+		t->page_pool_buf = NULL;
 		return t;
+	}
 
 	return mt76_alloc_txwi(dev);
 }
@@ -147,8 +151,8 @@ mt76_free_pending_rxwi(struct mt76_dev *dev)
 
 	local_bh_disable();
 	while ((t = __mt76_get_rxwi(dev)) != NULL) {
-		if (t->ptr)
-			mt76_put_page_pool_buf(t->ptr, false);
+		if (t->page_pool_buf)
+			mt76_put_page_pool_buf(t->page_pool_buf, false);
 		kfree(t);
 	}
 	local_bh_enable();
@@ -475,14 +479,14 @@ mt76_dma_get_rxdmad_c_buf(struct mt76_dev *dev, struct mt76_queue *q,
 	if (more)
 		*more = !FIELD_GET(RRO_RXDMAD_DATA1_LS_MASK, data1);
 
-	buf = t->ptr;
+	buf = t->page_pool_buf;
 	ind_reason = FIELD_GET(RRO_RXDMAD_DATA2_IND_REASON_MASK, data2);
 	if (ind_reason == MT_DMA_WED_IND_REASON_REPEAT ||
 	    ind_reason == MT_DMA_WED_IND_REASON_OLDPKT) {
 		mt76_put_page_pool_buf(buf, false);
 		buf = ERR_PTR(-EAGAIN);
 	}
-	t->ptr = NULL;
+	t->page_pool_buf = NULL;
 	t->dma_addr = 0;
 
 	mt76_put_rxwi(dev, t);
@@ -529,9 +533,9 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
 				SKB_WITH_OVERHEAD(q->buf_size),
 				page_pool_get_dma_dir(q->page_pool));
 
-		buf = t->ptr;
+		buf = t->page_pool_buf;
 		t->dma_addr = 0;
-		t->ptr = NULL;
+		t->page_pool_buf = NULL;
 
 		mt76_put_rxwi(dev, t);
 		if (drop)
@@ -694,6 +698,7 @@ mt76_dma_tx_queue_skb(struct mt76_phy *phy, struct mt76_queue *q,
 			goto unmap;
 
 		tx_info.buf[n].addr = addr;
+		tx_info.buf[n].skip_unmap = false;
 		tx_info.buf[n++].len = iter->len;
 	}
 	tx_info.nbuf = n;
@@ -718,9 +723,11 @@ mt76_dma_tx_queue_skb(struct mt76_phy *phy, struct mt76_queue *q,
 				tx_info.info, tx_info.skb, t);
 
 unmap:
-	for (n--; n > 0; n--)
-		dma_unmap_single(dev->dma_dev, tx_info.buf[n].addr,
-				 tx_info.buf[n].len, DMA_TO_DEVICE);
+	for (n--; n > 0; n--) {
+		if (!tx_info.buf[n].skip_unmap)
+			dma_unmap_single(dev->dma_dev, tx_info.buf[n].addr,
+					 tx_info.buf[n].len, DMA_TO_DEVICE);
+	}
 
 free:
 #ifdef CONFIG_NL80211_TESTMODE
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 527bef97e122..927c21536f4e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -445,10 +445,8 @@ struct mt76_txwi_cache {
 	struct list_head list;
 	dma_addr_t dma_addr;
 
-	union {
 		struct sk_buff *skb;
-		void *ptr;
-	};
+	void *page_pool_buf;
 
 	u8 qid;
 	u8 phy_idx;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
index e2a83da3a09c..924b0dc0ff1e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
@@ -1775,12 +1775,12 @@ static void mt7996_rx_token_put(struct mt7996_dev *dev)
 		struct mt76_txwi_cache *t;
 
 		t = mt76_rx_token_release(&dev->mt76, i);
-		if (!t || !t->ptr)
+		if (!t || !t->page_pool_buf)
 			continue;
 
-		mt76_put_page_pool_buf(t->ptr, false);
+		mt76_put_page_pool_buf(t->page_pool_buf, false);
 		t->dma_addr = 0;
-		t->ptr = NULL;
+		t->page_pool_buf = NULL;
 
 		mt76_put_rxwi(&dev->mt76, t);
 	}
@@ -1928,14 +1928,14 @@ void mt7996_rro_rx_process(struct mt76_dev *mdev, void *data)
 				goto next_page;
 
 			qid = t->qid;
-			buf = t->ptr;
+			buf = t->page_pool_buf;
 			q = &mdev->q_rx[qid];
 			dma_sync_single_for_cpu(mdev->dma_dev, t->dma_addr,
 						SKB_WITH_OVERHEAD(q->buf_size),
 						page_pool_get_dma_dir(q->page_pool));
 
 			t->dma_addr = 0;
-			t->ptr = NULL;
+			t->page_pool_buf = NULL;
 			mt76_put_rxwi(mdev, t);
 			if (!buf)
 				goto next_page;
diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 22f9690634c9..665156a7ea65 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -899,7 +899,7 @@ int mt76_rx_token_consume(struct mt76_dev *dev, void *ptr,
 	token = idr_alloc(&dev->rx_token, t, 0, dev->rx_token_size,
 			  GFP_ATOMIC);
 	if (token >= 0) {
-		t->ptr = ptr;
+		t->page_pool_buf = ptr;
 		t->dma_addr = phys;
 	}
 	spin_unlock_bh(&dev->rx_token_lock);
diff --git a/drivers/net/wireless/mediatek/mt76/wed.c b/drivers/net/wireless/mediatek/mt76/wed.c
index ed657d952de2..e1cf81d722b8 100644
--- a/drivers/net/wireless/mediatek/mt76/wed.c
+++ b/drivers/net/wireless/mediatek/mt76/wed.c
@@ -15,11 +15,11 @@ void mt76_wed_release_rx_buf(struct mtk_wed_device *wed)
 		struct mt76_txwi_cache *t;
 
 		t = mt76_rx_token_release(dev, i);
-		if (!t || !t->ptr)
+		if (!t || !t->page_pool_buf)
 			continue;
 
-		mt76_put_page_pool_buf(t->ptr, false);
-		t->ptr = NULL;
+		mt76_put_page_pool_buf(t->page_pool_buf, false);
+		t->page_pool_buf = NULL;
 
 		mt76_put_rxwi(dev, t);
 	}
-- 
2.45.2