wifi: mt76: handle possible mt76_rx_token_consume failures

Take into account possible error conditions of mt76_rx_token_consume
routine in mt7915_mmio_wed_init_rx_buf() and mt76_dma_add_buf()

Fixes: cd372b8c ("wifi: mt76: add WED RX support to mt76_dma_{add,get}_buf")
Fixes: 4f831d18 ("wifi: mt76: mt7915: enable WED RX support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -234,6 +234,9 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
 
 			rx_token = mt76_rx_token_consume(dev, (void *)skb, t,
 							 buf[0].addr);
+			if (rx_token < 0)
+				return -ENOMEM;
+
 			buf1 |= FIELD_PREP(MT_DMA_CTL_TOKEN, rx_token);
 			ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len) |
 			       MT_DMA_CTL_TO_HOST;
@@ -602,7 +605,12 @@ mt76_dma_rx_fill(struct mt76_dev *dev, struct mt76_queue *q)
 		qbuf.addr = addr + offset;
 		qbuf.len = len - offset;
 		qbuf.skip_unmap = false;
-		mt76_dma_add_buf(dev, q, &qbuf, 1, 0, buf, t);
+		if (mt76_dma_add_buf(dev, q, &qbuf, 1, 0, buf, t) < 0) {
+			dma_unmap_single(dev->dma_dev, addr, len,
+					 DMA_FROM_DEVICE);
+			skb_free_frag(buf);
+			break;
+		}
 		frames++;
 	}
 

drivers/net/wireless/mediatek/mt76/mt7915/mmio.c

@@ -653,6 +653,13 @@ static u32 mt7915_mmio_wed_init_rx_buf(struct mtk_wed_device *wed, int size)
 
 		desc->buf0 = cpu_to_le32(phy_addr);
 		token = mt76_rx_token_consume(&dev->mt76, ptr, t, phy_addr);
+		if (token < 0) {
+			dma_unmap_single(dev->mt76.dma_dev, phy_addr,
+					 wed->wlan.rx_size, DMA_TO_DEVICE);
+			skb_free_frag(ptr);
+			goto unmap;
+		}
+
 		desc->token |= cpu_to_le32(FIELD_PREP(MT_DMA_CTL_TOKEN,
 						      token));
 		desc++;

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

@@ -764,10 +764,11 @@ int mt76_rx_token_consume(struct mt76_dev *dev, void *ptr,
 	spin_lock_bh(&dev->rx_token_lock);
 	token = idr_alloc(&dev->rx_token, t, 0, dev->rx_token_size,
 			  GFP_ATOMIC);
-	spin_unlock_bh(&dev->rx_token_lock);
-
+	if (token >= 0) {
 		t->ptr = ptr;
 		t->dma_addr = phys;
+	}
+	spin_unlock_bh(&dev->rx_token_lock);
 
 	return token;
 }