wifi: mt76: Add mt76_dma_get_rxdmad_c_buf utility routione

Introduce mt76_dma_get_rxdmad_c_buf routine to process packets received
by HW-RRO v3.1 module.
This is a preliminary patch to introduce SW path for HW-RRO v3.1 module
available on MT7992 chipset.

Co-developed-by: Rex Lu <rex.lu@mediatek.com>
Signed-off-by: Rex Lu <rex.lu@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250909-mt7996-rro-rework-v5-15-7d66f6eb7795@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -427,15 +427,61 @@ mt76_dma_tx_cleanup(struct mt76_dev *dev, struct mt76_queue *q, bool flush)
 		wake_up(&dev->tx_wait);
 }
 
+static void *
+mt76_dma_get_rxdmad_c_buf(struct mt76_dev *dev, struct mt76_queue *q,
+			  int idx, int *len, bool *more)
+{
+	struct mt76_queue_entry *e = &q->entry[idx];
+	struct mt76_rro_rxdmad_c *dmad = e->buf;
+	u32 data1 = le32_to_cpu(dmad->data1);
+	u32 data2 = le32_to_cpu(dmad->data2);
+	struct mt76_txwi_cache *t;
+	u16 rx_token_id;
+	u8 ind_reason;
+	void *buf;
+
+	rx_token_id = FIELD_GET(RRO_RXDMAD_DATA2_RX_TOKEN_ID_MASK, data2);
+	t = mt76_rx_token_release(dev, rx_token_id);
+	if (!t)
+		return ERR_PTR(-EAGAIN);
+
+	q = &dev->q_rx[t->qid];
+	dma_sync_single_for_cpu(dev->dma_dev, t->dma_addr,
+				SKB_WITH_OVERHEAD(q->buf_size),
+				page_pool_get_dma_dir(q->page_pool));
+
+	if (len)
+		*len = FIELD_GET(RRO_RXDMAD_DATA1_SDL0_MASK, data1);
+	if (more)
+		*more = !FIELD_GET(RRO_RXDMAD_DATA1_LS_MASK, data1);
+
+	buf = t->ptr;
+	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->dma_addr = 0;
+
+	mt76_put_rxwi(dev, t);
+
+	return buf;
+}
+
 static void *
 mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
-		 int *len, u32 *info, bool *more, bool *drop)
+		 int *len, u32 *info, bool *more, bool *drop, bool flush)
 {
 	struct mt76_queue_entry *e = &q->entry[idx];
 	struct mt76_desc *desc = &q->desc[idx];
 	u32 ctrl, desc_info, buf1;
 	void *buf = e->buf;
 
+	if (mt76_queue_is_wed_rro_rxdmad_c(q) && !flush)
+		buf = mt76_dma_get_rxdmad_c_buf(dev, q, idx, len, more);
+
 	if (mt76_queue_is_wed_rro(q))
 		goto done;
 
@@ -516,7 +562,7 @@ mt76_dma_dequeue(struct mt76_dev *dev, struct mt76_queue *q, bool flush,
 	q->tail = (q->tail + 1) % q->ndesc;
 	q->queued--;
 
-	return mt76_dma_get_buf(dev, q, idx, len, info, more, drop);
+	return mt76_dma_get_buf(dev, q, idx, len, info, more, drop, flush);
 }
 
 static int
@@ -885,10 +931,16 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
 		if (!data)
 			break;
 
+		if (PTR_ERR(data) == -EAGAIN) {
+			done++;
+			continue;
+		}
+
 		if (mt76_queue_is_wed_rro_ind(q) && dev->drv->rx_rro_ind_process)
 			dev->drv->rx_rro_ind_process(dev, data);
 
-		if (mt76_queue_is_wed_rro(q)) {
+		if (mt76_queue_is_wed_rro(q) &&
+		    !mt76_queue_is_wed_rro_rxdmad_c(q)) {
 			done++;
 			continue;
 		}

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

@@ -58,6 +58,21 @@ struct mt76_wed_rro_desc {
 	__le32 buf1;
 } __packed __aligned(4);
 
+/* data1 */
+#define RRO_RXDMAD_DATA1_LS_MASK		BIT(30)
+#define RRO_RXDMAD_DATA1_SDL0_MASK		GENMASK(29, 16)
+/* data2 */
+#define RRO_RXDMAD_DATA2_RX_TOKEN_ID_MASK	GENMASK(31, 16)
+#define RRO_RXDMAD_DATA2_IND_REASON_MASK	GENMASK(15, 12)
+/* data3 */
+#define RRO_RXDMAD_DATA3_MAGIC_CNT_MASK		GENMASK(31, 28)
+struct mt76_rro_rxdmad_c {
+	__le32 data0;
+	__le32 data1;
+	__le32 data2;
+	__le32 data3;
+};
+
 enum mt76_qsel {
 	MT_QSEL_MGMT,
 	MT_QSEL_HCCA,

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

@@ -45,6 +45,7 @@
 #define MT_WED_RRO_Q_DATA(_n)	__MT_WED_RRO_Q(MT76_WED_RRO_Q_DATA, _n)
 #define MT_WED_RRO_Q_MSDU_PG(_n)	__MT_WED_RRO_Q(MT76_WED_RRO_Q_MSDU_PG, _n)
 #define MT_WED_RRO_Q_IND	__MT_WED_RRO_Q(MT76_WED_RRO_Q_IND, 0)
+#define MT_WED_RRO_Q_RXDMAD_C	__MT_WED_RRO_Q(MT76_WED_RRO_Q_RXDMAD_C, 0)
 
 struct mt76_dev;
 struct mt76_phy;
@@ -71,6 +72,7 @@ enum mt76_wed_type {
 	MT76_WED_RRO_Q_DATA,
 	MT76_WED_RRO_Q_MSDU_PG,
 	MT76_WED_RRO_Q_IND,
+	MT76_WED_RRO_Q_RXDMAD_C,
 };
 
 struct mt76_bus_ops {
@@ -1794,6 +1796,12 @@ static inline bool mt76_queue_is_wed_rro_ind(struct mt76_queue *q)
 	       FIELD_GET(MT_QFLAG_WED_TYPE, q->flags) == MT76_WED_RRO_Q_IND;
 }
 
+static inline bool mt76_queue_is_wed_rro_rxdmad_c(struct mt76_queue *q)
+{
+	return mt76_queue_is_wed_rro(q) &&
+	       FIELD_GET(MT_QFLAG_WED_TYPE, q->flags) == MT76_WED_RRO_Q_RXDMAD_C;
+}
+
 static inline bool mt76_queue_is_wed_rro_data(struct mt76_queue *q)
 {
 	return mt76_queue_is_wed_rro(q) &&